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Sample records for left occipital cortex

  1. Inattention Predicts Increased Thickness of Left Occipital Cortex in Men with Attention-Deficit/Hyperactivity Disorder

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    Peter Sörös

    2017-09-01

    Full Text Available BackgroundAttention-deficit/hyperactivity disorder (ADHD in adulthood is a serious and frequent psychiatric disorder with the core symptoms inattention, impulsivity, and hyperactivity. The principal aim of this study was to investigate associations between brain morphology, i.e., cortical thickness and volumes of subcortical gray matter, and individual symptom severity in adult ADHD.MethodsSurface-based brain morphometry was performed in 35 women and 29 men with ADHD using FreeSurfer. Linear regressions were calculated between cortical thickness and the volumes of subcortical gray matter and the inattention, hyperactivity, and impulsivity subscales of the Conners Adult ADHD Rating Scales (CAARS. Two separate analyses were performed. For the first analysis, age was included as additional regressor. For the second analysis, both age and severity of depression were included as additional regressors. Study participants were recruited between June 2012 and January 2014.ResultsLinear regression identified an area in the left occipital cortex of men, covering parts of the middle occipital sulcus and gyrus, in which the score on the CAARS inattention subscale predicted increased mean cortical thickness [F(1,27 = 26.27, p < 0.001, adjusted R2 = 0.4744]. No significant associations were found between cortical thickness and the scores on CAARS subscales in women. No significant associations were found between the volumes of subcortical gray matter and the scores on CAARS subscales, neither in men nor in women. These results remained stable when severity of depression was included as additional regressor, together with age.ConclusionIncreased cortical thickness in the left occipital cortex may represent a mechanism to compensate for dysfunctional attentional networks in male adult ADHD patients.

  2. Inattention Predicts Increased Thickness of Left Occipital Cortex in Men with Attention-Deficit/Hyperactivity Disorder.

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    Sörös, Peter; Bachmann, Katharina; Lam, Alexandra P; Kanat, Manuela; Hoxhaj, Eliza; Matthies, Swantje; Feige, Bernd; Müller, Helge H O; Thiel, Christiane; Philipsen, Alexandra

    2017-01-01

    Attention-deficit/hyperactivity disorder (ADHD) in adulthood is a serious and frequent psychiatric disorder with the core symptoms inattention, impulsivity, and hyperactivity. The principal aim of this study was to investigate associations between brain morphology, i.e., cortical thickness and volumes of subcortical gray matter, and individual symptom severity in adult ADHD. Surface-based brain morphometry was performed in 35 women and 29 men with ADHD using FreeSurfer. Linear regressions were calculated between cortical thickness and the volumes of subcortical gray matter and the inattention, hyperactivity, and impulsivity subscales of the Conners Adult ADHD Rating Scales (CAARS). Two separate analyses were performed. For the first analysis, age was included as additional regressor. For the second analysis, both age and severity of depression were included as additional regressors. Study participants were recruited between June 2012 and January 2014. Linear regression identified an area in the left occipital cortex of men, covering parts of the middle occipital sulcus and gyrus, in which the score on the CAARS inattention subscale predicted increased mean cortical thickness [ F (1,27) = 26.27, p  attentional networks in male adult ADHD patients.

  3. Occipital cortex of blind individuals is functionally coupled with executive control areas of frontal cortex.

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    Deen, Ben; Saxe, Rebecca; Bedny, Marina

    2015-08-01

    In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.

  4. Modality-specific involvement of occipital cortex in Early Blind?

    NARCIS (Netherlands)

    van der Lubbe, Robert Henricus Johannes; van Mierlo, C.M.; Postma, A.

    2008-01-01

    What happens in occipital cortex when neuronal activity is no longer evoked by regular visual stimulation? Studying brain activity induced by tactile and auditory stimuli in the blind may provide an answer. Several studies indicate that occipital cortex in the blind is recruited in simple tasks,

  5. Leptomeningeal angiomatosis of the left occipital surface detected by CT scan

    International Nuclear Information System (INIS)

    Niiro, Masaki; Mihara, Tadahiro; Maeda, Yoshiki; Awa, Hiroshi; Kadota, Koki; Asakura, Tetsuhiko

    1982-01-01

    A case of left occipital leptomeningeal angiomatosis was reported. The patient was a 12-year-old boy who had episodes of severe vascular type headache accompanied by transient right homonymous hemianopsia. CT scan showed localized superficial high density area in the left occipital pole. Remarkable enhancement of the lower and inner surface of the left occipital lobe was demonstrated. Angiography showed poor filling of the distal portion of the left posterior cerebral artery. Skull tomograms showed linear calcifications in the left occipital region. Brain scan showed increased RI uptake in the left occipital region. During operation, the surface of the left occipital lobe was covered by excessive, fine, vascular networks which extended over the arachnoid membrane. The abnormal vessels were cauterized by a CO 2 laser as throughly as possible. The occipital pole, felt gritty. Histologically, the abnormal vessels had spread into the subarachnoid space and were predominantly veins with thin and enlarged walls. The abnormal vessels followed the leptomeninges in the sulci of the cerebral cortex. Underneath the abnormal vessels, in the external layers of the cerebral cortex, calcium deposits were scattered and gliosis and degeneration of the ganglion cells were observed. The lesion was comparable with leptomeningeal angiomatosis. Though the pathological findings of the specimen, CT findings, and brain scan findings were extremely similar to those of Sturge-Weber disease, in this case, the typical clinical and roentgenographic findings of Sturge-Weber disease were all absent. (author)

  6. The occipital cortex in detection and categorisation abilities: an fMRI study in hemianopia

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    Perez, C.; Coubard, O.; Cavezian, C.; Gout, O.; Chokron, S.; Peyrin, C.; Andersson, F.; Doucet, G.

    2011-01-01

    Complete text of publication follows: Previous studies have shown that the right and left hemispheres are predominant for detection and categorization tasks, respectively. This asymmetry appears to be instantiated at a processing stage as early as the occipital cortex. The present study was intended to assess the cerebral network responsible for natural scenes perception in hemianopic patients suffering from an occipital cortex lesion. One Left and one Right hemianopic patient (LH or RH; respectively right and left occipital damage) were compared with 14 healthy controls in detection and categorisation tasks of natural scenes. Both tasks were performed in a 1.5 T scanner to collect anatomical and functional data. In healthy controls, occipital activation was observed in the extra-striate areas of both hemispheres in the detection task but only of the left hemisphere in the categorization task. The LH (patient showed a bilateral occipital activation in both tasks. while, the RH patient showed unilateral right (intact) occipital activation in both tasks. These results highlight the importance of the perceptual task (detection vs. categorization) on the hemispheric asymmetry. They also suggest that different cortical reorganisations take place depending on the occipital lesion side

  7. Progressive microstructural changes of the occipital cortex in Huntington's disease.

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    Odish, Omar F F; Reijntjes, Robert H A M; van den Bogaard, Simon J A; Roos, Raymund A C; Leemans, Alexander

    2018-02-28

    In this study we longitudinally investigated the rate of microstructural alterations in the occipital cortex in different stages of Huntington's disease (HD) by applying an automated atlas-based approach to diffusion MRI data. Twenty-two premanifest (preHD), 10 early manifest HD (early HD) and 24 healthy control subjects completed baseline and two year follow-up scans. The preHD group was stratified based on the predicted years to disease onset into a far (preHD-A) and near (preHD-B) to disease onset group. Clinical and behavioral measures were collected per assessment time point. An automated atlas-based DTI analysis approach was used to obtain the mean, axial and radial diffusivities of the occipital cortex. We found that the longitudinal rate of diffusivity change in the superior occipital gyrus (SOG), middle occipital gyrus (MOG), and inferior occipital gyrus (IOG) was significantly higher in early HD compared to both preHD and controls (all p's ≤ 0.005), which can be interpreted as an increased rate of microstructural degeneration. Furthermore, the change rate in the diffusivity of the MOG could significantly discriminate between preHD-B compared to preHD-A and the other groups (all p's ≤ 0.04). Finally, we found an inverse correlation between the Stroop Word Reading task and diffusivities in the SOG and MOG (all p's ≤ 0.01). These findings suggest that measures obtained from the occipital cortex can serve as sensitive longitudinal biomarkers for disease progression in preHD-B and early HD. These could in turn be used to assess potential effects of proposed disease modifying therapies.

  8. Androgen receptor immunoreactivity in rat occipital cortex after callosotomy

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    G Lepore

    2009-08-01

    Full Text Available Gonadal steroidogenesis can be influenced by direct neural links between the central nervous system and the gonads. It is known that androgen receptor (AR is expressed in many areas of the rat brain involved in neuroendocrine control of reproduction, such as the cerebral cortex. It has been recently shown that the occipital cortex exerts an inhibitory effect on testicular stereoidogenesis by a pituitary-independent neural mechanism. Moreover, the complete transection of the corpus callosum leads to an increase in testosterone (T secretion of hemigonadectomized rats. The present study was undertaken to analyze the possible corticocortical influences regulating male reproductive activities. Adult male Wistar rats were divided into 4 groups: 1 intact animals as control; 2 rats undergoing sham callosotomy; 3 posterior callosotomy; 4 gonadectomy and posterior callosotomy. Western blot analysis showed no remarkable variations in cortical AR expression in any of the groups except in group I where a significant decrease in AR levels was found. Similarly, both immunocytochemical study and cell count estimation showed a lower AR immunoreactivity in occipital cortex of callosotomized rats than in other groups. In addition, there was no difference in serum T and LH concentration between sham-callosotomized and callosotomized rats. In conclusion, our results show that posterior callosotomy led to a reduction in AR in the right occipital cortex suggesting a putative inhibiting effect of the contralateral cortical area.

  9. Riluzole Effect on Occipital Cortex: A Structural and Spectroscopy Pilot Study

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    Abdallah, Chadi G.; Coplan, Jeremy D.; Jackowski, Andrea; Sato, João R.; Mao, Xiangling; Shungu, Dikoma C.; Mathew, Sanjay J.

    2012-01-01

    Background To investigate the mechanism underlying the anxiolytic properties of riluzole, a glutamate-modulating agent, we previously studied the effect of this drug on hippocampal N-Acetylaspartate (NAA) and volume in patients with Generalized Anxiety Disorder (GAD). In the same cohort, we now extend our investigation to the occipital cortex, a brain region that was recently implicated in the antidepressant effect of riluzole. Methods Fourteen medication-free adult patients with GAD received 8-week of open-label riluzole. Ten healthy subjects served as a comparison group. The healthy group did not receive riluzole treatment. Both groups underwent magnetic resonance imaging and spectroscopy at baseline and at the end of Week 8. Hamilton Anxiety Rating Scale (HAM-A) and Penn State Worry Questionnaire (PSWQ) were used as the primary and secondary outcome measures, respectively. Results At baseline, we found clusters of increased cortical thickness in the occipital region in GAD compared to healthy subjects. In the right hemisphere, eight weeks of treatment reduced occipital cortical thickness in the GAD group (t = 3.67, p = 0.004). In addition, the improvement in HAM-A scores was negatively correlated with post-treatment right occipital NAA (r = − 0.68, p = 0.008), and with changes in NAA levels (r = − 0.53, p = 0.051). In the left hemisphere, we found positive associations between changes in occipital cortical thickness and improvement in HAM-A (r = 0.60, p = 0.04) and PSWQ (r = 0.62, p = 0.03). Conclusion These pilot findings implicate the occipital cortex as a brain region associated with pathology and clinical improvement in GAD. In addition, the region specific effect of riluzole implies a distinct pathophysiology in the occipital cortex – compared to other, previously studied, frontolimbic brain structures. PMID:23043888

  10. Right Occipital Cortex Activation Correlates with Superior Odor Processing Performance in the Early Blind

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    Grandin, Cécile B.; Dricot, Laurence; Plaza, Paula; Lerens, Elodie; Rombaux, Philippe; De Volder, Anne G.

    2013-01-01

    Using functional magnetic resonance imaging (fMRI) in ten early blind humans, we found robust occipital activation during two odor-processing tasks (discrimination or categorization of fruit and flower odors), as well as during control auditory-verbal conditions (discrimination or categorization of fruit and flower names). We also found evidence for reorganization and specialization of the ventral part of the occipital cortex, with dissociation according to stimulus modality: the right fusiform gyrus was most activated during olfactory conditions while part of the left ventral lateral occipital complex showed a preference for auditory-verbal processing. Only little occipital activation was found in sighted subjects, but the same right-olfactory/left-auditory-verbal hemispheric lateralization was found overall in their brain. This difference between the groups was mirrored by superior performance of the blind in various odor-processing tasks. Moreover, the level of right fusiform gyrus activation during the olfactory conditions was highly correlated with individual scores in a variety of odor recognition tests, indicating that the additional occipital activation may play a functional role in odor processing. PMID:23967263

  11. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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    Andreas A Ioannides

    2013-08-01

    Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  12. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

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    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  13. Stereoscopic vision in the absence of the lateral occipital cortex.

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    Jenny C A Read

    2010-09-01

    Full Text Available Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better than many control observers at using binocular disparity to judge whether an isolated object appears near or far, and to resolve ambiguous structure-from-motion. DF is, however, poor at using relative disparity between features at different locations across the visual field. This may stem from a difficulty in identifying the surface boundaries where relative disparity is available. We suggest that the ventral processing stream may play a critical role in enabling healthy observers to extract fine depth information from relative disparities within one surface or between surfaces located in different parts of the visual field.

  14. Neuronal populations in the occipital cortex of the blind synchronize to the temporal dynamics of speech

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    Van Ackeren, Markus Johannes; Barbero, Francesca M; Mattioni, Stefania; Bottini, Roberto

    2018-01-01

    The occipital cortex of early blind individuals (EB) activates during speech processing, challenging the notion of a hard-wired neurobiology of language. But, at what stage of speech processing do occipital regions participate in EB? Here we demonstrate that parieto-occipital regions in EB enhance their synchronization to acoustic fluctuations in human speech in the theta-range (corresponding to syllabic rate), irrespective of speech intelligibility. Crucially, enhanced synchronization to the intelligibility of speech was selectively observed in primary visual cortex in EB, suggesting that this region is at the interface between speech perception and comprehension. Moreover, EB showed overall enhanced functional connectivity between temporal and occipital cortices that are sensitive to speech intelligibility and altered directionality when compared to the sighted group. These findings suggest that the occipital cortex of the blind adopts an architecture that allows the tracking of speech material, and therefore does not fully abstract from the reorganized sensory inputs it receives. PMID:29338838

  15. Activation of the occipital cortex and deactivation of the default mode network during working memory in the early blind.

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    Park, Hae-Jeong; Chun, Ji-Won; Park, Bumhee; Park, Haeil; Kim, Joong Il; Lee, Jong Doo; Kim, Jae-Jin

    2011-05-01

    Although blind people heavily depend on working memory to manage daily life without visual information, it is not clear yet whether their working memory processing involves functional reorganization of the memory-related cortical network. To explore functional reorganization of the cortical network that supports various types of working memory processes in the early blind, we investigated activation differences between 2-back tasks and 0-back tasks using fMRI in 10 congenitally blind subjects and 10 sighted subjects. We used three types of stimulus sequences: words for a verbal task, pitches for a non-verbal task, and sound locations for a spatial task. When compared to the sighted, the blind showed additional activations in the occipital lobe for all types of stimulus sequences for working memory and more significant deactivation in the posterior cingulate cortex of the default mode network. The blind had increased effective connectivity from the default mode network to the left parieto-frontal network and from the occipital cortex to the right parieto-frontal network during the 2-back tasks than the 0-back tasks. These findings suggest not only cortical plasticity of the occipital cortex but also reorganization of the cortical network for the executive control of working memory.

  16. TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers.

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    Ptito, M; Fumal, A; de Noordhout, A Martens; Schoenen, J; Gjedde, A; Kupers, R

    2008-01-01

    Various non-visual inputs produce cross-modal responses in the visual cortex of early blind subjects. In order to determine the qualitative experience associated with these occipital activations, we systematically stimulated the entire occipital cortex using single pulse transcranial magnetic stimulation (TMS) in early blind subjects and in blindfolded seeing controls. Whereas blindfolded seeing controls reported only phosphenes following occipital cortex stimulation, some of the blind subjects reported tactile sensations in the fingers that were somatotopically organized onto the visual cortex. The number of cortical sites inducing tactile sensations appeared to be related to the number of hours of Braille reading per day, Braille reading speed and dexterity. These data, taken in conjunction with previous anatomical, behavioural and functional imaging results, suggest the presence of a polysynaptic cortical pathway between the somatosensory cortex and the visual cortex in early blind subjects. These results also add new evidence that the activity of the occipital lobe in the blind takes its qualitative expression from the character of its new input source, therefore supporting the cortical deference hypothesis.

  17. [Total dream loss secondary to left temporo-occipital brain injury].

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    Poza, J J; Martí Massó, J F

    2006-04-01

    Recently the case of a woman who reported cessation of dreaming after a bilateral PCA stroke but without REM sleep loss has been reported, suggesting that deep bilateral occipital lobe damage including the right inferior lingual gyrus may represent the "minimal lesion extension" necessary for dream loss. We report the case of a 24-year-old man who ceased dreaming after a unilateral left temporo- occipital hematoma. The polysomnographic characteristics in rapid eyes movements (REM) sleep were otherwise normal. Our patient demonstrates that a unilateral left temporo-occipital injury could be sufficient for losing dreams.

  18. Relevance of Spectral Cues for Auditory Spatial Processing in the Occipital Cortex of the Blind

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    Voss, Patrice; Lepore, Franco; Gougoux, Frédéric; Zatorre, Robert J.

    2011-01-01

    We have previously shown that some blind individuals can localize sounds more accurately than their sighted counterparts when one ear is obstructed, and that this ability is strongly associated with occipital cortex activity. Given that spectral cues are important for monaurally localizing sounds when one ear is obstructed, and that blind individuals are more sensitive to small spectral differences, we hypothesized that enhanced use of spectral cues via occipital cortex mechanisms could explain the better performance of blind individuals in monaural localization. Using positron-emission tomography (PET), we scanned blind and sighted persons as they discriminated between sounds originating from a single spatial position, but with different spectral profiles that simulated different spatial positions based on head-related transfer functions. We show here that a sub-group of early blind individuals showing superior monaural sound localization abilities performed significantly better than any other group on this spectral discrimination task. For all groups, performance was best for stimuli simulating peripheral positions, consistent with the notion that spectral cues are more helpful for discriminating peripheral sources. PET results showed that all blind groups showed cerebral blood flow increases in the occipital cortex; but this was also the case in the sighted group. A voxel-wise covariation analysis showed that more occipital recruitment was associated with better performance across all blind subjects but not the sighted. An inter-regional covariation analysis showed that the occipital activity in the blind covaried with that of several frontal and parietal regions known for their role in auditory spatial processing. Overall, these results support the notion that the superior ability of a sub-group of early-blind individuals to localize sounds is mediated by their superior ability to use spectral cues, and that this ability is subserved by cortical processing in

  19. [A patient with prosopagnosia which developed after an infarction in the left occipital lobe in addition to an old infarction in the right occipital lobe].

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    Iwanaga, Keisuke; Satoh, Akira; Satoh, Hideyo; Seto, Makiko; Ochi, Makoto; Tsujihata, Mitsuhiro

    2011-05-01

    A 66-year-old, right-handed male, was admitted to our hospital with difficulty in recognizing faces and colors. He had suffered a stroke in the right occipital region three years earlier that had induced left homonymous hemianopsia, but not prosopagnosia. A neurological examination revealed prosopagnosia, color agnosia, constructional apraxia, and topographical disorientation, but not either hemineglect or dressing apraxia. The patient was unable to distinguish faces of familiar persons such as his family and friends, as well as those of unfamiliar persons such as doctors and nurses. Brain MRI demonstrated an old infarction in the right medial occipital lobe and a new hemorrhagic infarction in the left medial occipital lobe, including the fusiform and lingual gyrus. It is unclear whether a purely right medial occipital lesion can be responsible for prosopagnosia, or whether bilateral medial occipital lesions are necessary for this occurrence. The current case indicated that bilateral medial occipital lesions play an important role in inducing porsopagnosia.

  20. Imagery of a moving object: the role of occipital cortex and human MT/V5+.

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    Kaas, Amanda; Weigelt, Sarah; Roebroeck, Alard; Kohler, Axel; Muckli, Lars

    2010-01-01

    Visual imagery--similar to visual perception--activates feature-specific and category-specific visual areas. This is frequently observed in experiments where the instruction is to imagine stimuli that have been shown immediately before the imagery task. Hence, feature-specific activation could be related to the short-term memory retrieval of previously presented sensory information. Here, we investigated mental imagery of stimuli that subjects had not seen before, eliminating the effects of short-term memory. We recorded brain activation using fMRI while subjects performed a behaviourally controlled guided imagery task in predefined retinotopic coordinates to optimize sensitivity in early visual areas. Whole brain analyses revealed activation in a parieto-frontal network and lateral-occipital cortex. Region of interest (ROI) based analyses showed activation in left hMT/V5+. Granger causality mapping taking left hMT/V5+ as source revealed an imagery-specific directed influence from the left inferior parietal lobule (IPL). Interestingly, we observed a negative BOLD response in V1-3 during imagery, modulated by the retinotopic location of the imagined motion trace. Our results indicate that rule-based motion imagery can activate higher-order visual areas involved in motion perception, with a role for top-down directed influences originating in IPL. Lower-order visual areas (V1, V2 and V3) were down-regulated during this type of imagery, possibly reflecting inhibition to avoid visual input from interfering with the imagery construction. This suggests that the activation in early visual areas observed in previous studies might be related to short- or long-term memory retrieval of specific sensory experiences.

  1. Distinct Oscillatory Frequencies Underlie Excitability of Human Occipital and Parietal Cortex.

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    Samaha, Jason; Gosseries, Olivia; Postle, Bradley R

    2017-03-15

    Transcranial magnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes. We used near-threshold TMS with concurrent EEG recordings to measure how oscillatory brain dynamics covary, on single trials, with the perception of phosphenes after occipital and parietal TMS. Prestimulus power and phase, predominantly in the alpha band (8-13 Hz), predicted occipital TMS phosphenes, whereas higher-frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS-evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (∼5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception of near-threshold visual stimuli. The regionally differential pattern of prestimulus predictors of phosphene perception suggests that distinct frequencies may reflect cortical excitability in occipital versus posterior parietal cortex, calling into question the broader assumption that the alpha rhythm may serve as a general index of cortical excitability. SIGNIFICANCE STATEMENT Alpha-band oscillations are thought to reflect cortical excitability and are therefore ascribed an important role in gating information transmission across cortex. We probed cortical excitability directly in human occipital and parietal cortex and observed that, whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes (phosphenes), which were manifest in both early and late patterns of evoked activity, revealing the time

  2. Grammatical distinctions in the left frontal cortex.

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    Shapiro, K A; Pascual-Leone, A; Mottaghy, F M; Gangitano, M; Caramazza, A

    2001-08-15

    Selective deficits in producing verbs relative to nouns in speech are well documented in neuropsychology and have been associated with left hemisphere frontal cortical lesions resulting from stroke and other neurological disorders. The basis for these impairments is unresolved: Do they arise because of differences in the way grammatical categories of words are organized in the brain, or because of differences in the neural representation of actions and objects? We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of a portion of left prefrontal cortex and to assess its role in producing nouns and verbs. In one experiment subjects generated real words; in a second, they produced pseudowords as nouns or verbs. In both experiments, response latencies increased for verbs but were unaffected for nouns following rTMS. These results demonstrate that grammatical categories have a neuroanatomical basis and that the left prefrontal cortex is selectively engaged in processing verbs as grammatical objects.

  3. Functional organization of the face-sensitive areas in human occipital-temporal cortex.

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    Shao, Hanyu; Weng, Xuchu; He, Sheng

    2017-08-15

    face-selective response similarity with r-pFFA and r-OFA, indicating it was specifically involved in processing face information. Results also reveal two properties of these face sensitive regions across the two hemispheres: (1) the averaged left intra-hemispheric response similarity for the images was lower than the averaged right intra-hemispheric and the inter-hemispheric response similarity, implying convergence of face processing towards the right hemisphere, and (2) the response similarities between homologous regions in the two hemispheres decreased as information processing proceeded from the early, more posterior, processing stage (OFA), indicating an increasing degree of hemispheric specialization and right hemisphere bias for face information processing. This study contributes to an emerging picture of how faces are processed within the occipital and temporal cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Differential contribution of right and left temporo-occipital and anterior temporal lesions to face recognition disorders

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    Guido eGainotti

    2011-06-01

    Full Text Available In the study of prosopagnosia, several issues (such as the specific or non-specific manifestations of prosopagnosia, the unitary or non-unitary nature of this syndrome and the mechanisms underlying face recognition disorders are still controversial. Two main sources of variance partially accounting for these controversies could be the qualitative differences between the face recognition disorders observed in patients with prevalent lesions of the right or left hemisphere and in those with lesions encroaching upon the temporo-occipital or the (right anterior temporal cortex.Results of our review seem to confirm these suggestions. Indeed, they show that (a the most specific forms of prosopagnosia are due to lesions of a right posterior network including the OFA and the FFA, whereas (b the face identification defects observed in patients with left temporo-occipital lesions seem due to a semantic defect impeding access to person-specific semantic information from the visual modality. Furthermore, face recognition defects resulting from right anterior temporal lesions can usually be considered as part of a multimodal people recognition disorder.The implications of our review are, therefore, the following: (1 to consider the components of visual agnosia often observed in prosopagnosic patients with bilateral temporo-occipital lesions as part of a semantic defect, resulting from left-sided lesions (and not from prosopagnosia proper; (2 to systematically investigate voice recognition disorders in patients with right anterior temporal lesions to determine whether the face recognition defect should be considered a form of ‘associative prosopagnosia’ or a form of the ‘multimodal people recognition disorder’.

  5. Spontaneous and visually-driven high-frequency oscillations in the occipital cortex: Intracranial recording in epileptic patients

    Science.gov (United States)

    Nagasawa, Tetsuro; Juhász, Csaba; Rothermel, Robert; Hoechstetter, Karsten; Sood, Sandeep; Asano, Eishi

    2011-01-01

    SUMMARY High-frequency oscillations (HFOs) at ≧80 Hz of nonepileptic nature spontaneously emerge from human cerebral cortex. In 10 patients with extra-occipital lobe epilepsy, we compared the spectral-spatial characteristics of HFOs spontaneously arising from the nonepileptic occipital cortex with those of HFOs driven by a visual task as well as epileptogenic HFOs arising from the extra-occipital seizure focus. We identified spontaneous HFOs at ≧80 Hz with a mean duration of 330 msec intermittently emerging from the occipital cortex during interictal slow-wave sleep. The spectral frequency band of spontaneous occipital HFOs was similar to that of visually-driven HFOs. Spontaneous occipital HFOs were spatially sparse and confined to smaller areas, whereas visually-driven HFOs involved the larger areas including the more rostral sites. Neither spectral frequency band nor amplitude of spontaneous occipital HFOs significantly differed from those of epileptogenic HFOs. Spontaneous occipital HFOs were strongly locked to the phase of delta activity, but the strength of delta-phase coupling decayed from 1 to 3 Hz. Conversely, epileptogenic extra-occipital HFOs were locked to the phase of delta activity about equally in the range from 1 to 3 Hz. The occipital cortex spontaneously generates physiological HFOs which may stand out on electrocorticography traces as prominently as pathological HFOs arising from elsewhere; this observation should be taken into consideration during presurgical evaluation. Coupling of spontaneous delta and HFOs may increase the understanding of significance of delta-oscillations during slow-wave sleep. Further studies are warranted to determine whether delta-phase coupling distinguishes physiological from pathological HFOs or simply differs across anatomical locations. PMID:21432945

  6. Alpha2-adrenoceptor modulation of long-term potentiation elicited in vivo in rat occipital cortex.

    Science.gov (United States)

    Mondaca, Mauricio; Hernández, Alejandro; Pérez, Hernán; Valladares, Luis; Sierralta, Walter; Fernández, Victor; Soto-Moyano, Rubén

    2004-09-24

    Pretreatment with the alpha(2)-adrenoceptor agonist clonidine (31.25, 62.5, or 125 microg/kg, i.p.) dose-dependently reduced long-term potentiation (LTP) elicited in vivo in the occipital cortex of anesthetized rats, whereas pretreatment with the alpha(2)-adrenoceptor antagonist yohimbine (0.133, 0.4, or 1.2 mg/kg, i.p.) increased neocortical LTP in a dose-dependent fashion. These effects could be related to the reported disruptive and facilitatory actions induced on memory formation by pretreatment with alpha(2)-adrenoceptor agonists and antagonists, respectively.

  7. Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex.

    Science.gov (United States)

    Ptak, Radek; Lazeyras, François; Di Pietro, Marie; Schnider, Armin; Simon, Stéphane R

    2014-07-01

    Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studied a patient with object agnosia following isolated damage to the left occipito-temporal cortex overlapping with the LOC. The patient showed intact processing of object structure, yet often made identification errors that were mainly based on the global visual similarity between objects. Using functional Magnetic Resonance Imaging (fMRI) we found that the damaged as well as the contralateral, structurally intact right LOC failed to show any object-selective fMRI activity, though the latter retained selectivity for faces. Thus, unilateral damage to the left LOC led to a bilateral breakdown of neural responses to a specific stimulus class (objects and artefacts) while preserving the response to a different stimulus class (faces). These findings indicate that representations of structure necessary for the identification of objects crucially rely on bilateral, distributed coding of shape features. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Cystic solitary fibrous tumor arising from the left occipital meninges: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Bae Geun; Hwang, Yoon Joon; Cha, Soon Joo; Hur, Gham; Kim, Yong Hoon; Kim, Su Young; Seo, Jung Wook; Lee, Ji Young; Kim, Han Seung [Ilsan Paik Hospital, Inje University, School of Medicine, Goyang (Korea, Republic of)

    2007-02-15

    Solitary fibrous tumor (SFT) is a benign mesenchymal neoplasm of a spindle-cell origin, and it usually involves the pleura. It's occurrence in various organs of the body has recently been described. Meningeal SFT is very rare. Radiologically, it is a strongly enhancing solid mass and is undistinguishable from fibrous meningioma and hemangiopericytoma. Yet we report here on a case of SFT with massive cystic degeneration that arose from the meninges of the left occipital region.

  9. Dissociative Disturbance in Hangul-Hanja Reading after a Left Posterior Occipital Lesion

    Directory of Open Access Journals (Sweden)

    Key-Chung Park

    2008-01-01

    Full Text Available Since the Korean language has two distinct writing systems, phonogram (Hangul and ideogram (Hanja: Chinese characters, alexia can present with dissociative disturbances in reading between the two systems. A 74-year-old right-handed man presented with a prominent reading impairment in Hangul with agraphia of both Hangul and Hanja after a left posterior occipital- parietal lesion. He could not recognize single syllable words and nonwords in Hangul, and visual errors were predominant in both Hanja reading and the Korean Boston Naming Test. In addition, he had difficulties in visuoperceptual tests including Judgment of Line Orientation, Hierarchical Navon figures, and complex picture scanning. These findings are consistent with the hypothesis that Hangul reading impairment results from a general visual perceptual deficit. However, this assumption cannot explain why performance on visually complex Hanja was better than performance on visually simple Hanja in our patient. In addition, the patient did not demonstrate higher accuracy on Hanja characters with fewer strokes than on words with more strokes. Thus, we speculate that the left posterior occipital area may be specialized for Hangul letter identification in this patient. This case demonstrates that Hangul-Hanja reading dissociation impairment can occur after occipital-parietal lesions.

  10. MRI in occipital lobe infarcts: classification by involvement of the striate cortex

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, M. [Department of Radiology, Kumamoto University School of Medicine, Kumamoto (Japan)]|[Department of Radiology, Kumamoto Rousai Hospital, Kumamoto (Japan); Korogi, Y.; Takahashi, M. [Department of Radiology, Kumamoto University School of Medicine, Kumamoto (Japan); Kido, T.; Ikeda, O.; Morishita, S. [Department of Radiology, Kumamoto Rousai Hospital, Kumamoto (Japan)

    1998-11-01

    We reviewed the MRI studies of 25 patients with occipital lobe infarcts to clarify the distribution of infarcts in the posterior cerebral arterial territory, focussing on their relationship to the striate cortex. Visual field defects and MRI findings were also correlated in 16 patients. On coronal and/or sagittal images, the distribution of the infarct and its relationship to the striate cortex were classified. Involvement of the cortex of both upper and lower lips of the calcarine fissure was observed in 10 patients, and involvement of the lower lip alone in 15. The upper cortical lesions were always accompanied by lower cortical lesions. The visual field defects were complete hemianopia in nine patients, superior quadrantanopia in six and hemianopia with a preserved temporal crescent in one. All patients with superior quadrantanopia had involvement of the lower cortex alone; there were no cases of inferior quadrantanopia. The characteristic vascular anatomy, and poor development of the collateral circulation in the lower cortical area, may explain the vulnerability of this area to infarcts. (orig.) With 6 figs., 21 refs.

  11. Recruitment of occipital cortex during sensory substitution training linked to subjective experience of seeing in people with blindness.

    Directory of Open Access Journals (Sweden)

    Tomás Ortiz

    Full Text Available Over three months of intensive training with a tactile stimulation device, 18 blind and 10 blindfolded seeing subjects improved in their ability to identify geometric figures by touch. Seven blind subjects spontaneously reported 'visual qualia', the subjective sensation of seeing flashes of light congruent with tactile stimuli. In the latter subjects tactile stimulation evoked activation of occipital cortex on electroencephalography (EEG. None of the blind subjects who failed to experience visual qualia, despite identical tactile stimulation training, showed EEG recruitment of occipital cortex. None of the blindfolded seeing humans reported visual-like sensations during tactile stimulation. These findings support the notion that the conscious experience of seeing is linked to the activation of occipital brain regions in people with blindness. Moreover, the findings indicate that provision of visual information can be achieved through non-visual sensory modalities which may help to minimize the disability of blind individuals, affording them some degree of object recognition and navigation aid.

  12. Recruitment of occipital cortex during sensory substitution training linked to subjective experience of seeing in people with blindness.

    Science.gov (United States)

    Ortiz, Tomás; Poch, Joaquín; Santos, Juan M; Requena, Carmen; Martínez, Ana M; Ortiz-Terán, Laura; Turrero, Agustín; Barcia, Juan; Nogales, Ramón; Calvo, Agustín; Martínez, José M; Córdoba, José L; Pascual-Leone, Alvaro

    2011-01-01

    Over three months of intensive training with a tactile stimulation device, 18 blind and 10 blindfolded seeing subjects improved in their ability to identify geometric figures by touch. Seven blind subjects spontaneously reported 'visual qualia', the subjective sensation of seeing flashes of light congruent with tactile stimuli. In the latter subjects tactile stimulation evoked activation of occipital cortex on electroencephalography (EEG). None of the blind subjects who failed to experience visual qualia, despite identical tactile stimulation training, showed EEG recruitment of occipital cortex. None of the blindfolded seeing humans reported visual-like sensations during tactile stimulation. These findings support the notion that the conscious experience of seeing is linked to the activation of occipital brain regions in people with blindness. Moreover, the findings indicate that provision of visual information can be achieved through non-visual sensory modalities which may help to minimize the disability of blind individuals, affording them some degree of object recognition and navigation aid.

  13. Augmenting distractor filtering via transcranial magnetic stimulation of the lateral occipital cortex.

    Science.gov (United States)

    Eštočinová, Jana; Lo Gerfo, Emanuele; Della Libera, Chiara; Chelazzi, Leonardo; Santandrea, Elisa

    2016-11-01

    Visual selective attention (VSA) optimizes perception and behavioral control by enabling efficient selection of relevant information and filtering of distractors. While focusing resources on task-relevant information helps counteract distraction, dedicated filtering mechanisms have recently been demonstrated, allowing neural systems to implement suitable policies for the suppression of potential interference. Limited evidence is presently available concerning the neural underpinnings of these mechanisms, and whether neural circuitry within the visual cortex might play a causal role in their instantiation, a possibility that we directly tested here. In two related experiments, transcranial magnetic stimulation (TMS) was applied over the lateral occipital cortex of healthy humans at different times during the execution of a behavioral task which entailed varying levels of distractor interference and need for attentional engagement. While earlier TMS boosted target selection, stimulation within a restricted time epoch close to (and in the course of) stimulus presentation engendered selective enhancement of distractor suppression, by affecting the ongoing, reactive instantiation of attentional filtering mechanisms required by specific task conditions. The results attest to a causal role of mid-tier ventral visual areas in distractor filtering and offer insights into the mechanisms through which TMS may have affected ongoing neural activity in the stimulated tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Exploratory Metabolomic Analyses Reveal Compounds Correlated with Lutein Concentration in Frontal Cortex, Hippocampus, and Occipital Cortex of Human Infant Brain.

    Directory of Open Access Journals (Sweden)

    Jacqueline C Lieblein-Boff

    Full Text Available Lutein is a dietary carotenoid well known for its role as an antioxidant in the macula, and recent reports implicate a role for lutein in cognitive function. Lutein is the dominant carotenoid in both pediatric and geriatric brain tissue. In addition, cognitive function in older adults correlated with macular and postmortem brain lutein concentrations. Furthermore, lutein was found to preferentially accumulate in the infant brain in comparison to other carotenoids that are predominant in diet. While lutein is consistently related to cognitive function, the mechanisms by which lutein may influence cognition are not clear. In an effort to identify potential mechanisms through which lutein might influence neurodevelopment, an exploratory study relating metabolite signatures and lutein was completed. Post-mortem metabolomic analyses were performed on human infant brain tissues in three regions important for learning and memory: the frontal cortex, hippocampus, and occipital cortex. Metabolomic profiles were compared to lutein concentration, and correlations were identified and reported here. A total of 1276 correlations were carried out across all brain regions. Of 427 metabolites analyzed, 257 were metabolites of known identity. Unidentified metabolite correlations (510 were excluded. In addition, moderate correlations with xenobiotic relationships (2 or those driven by single outliers (3 were excluded from further study. Lutein concentrations correlated with lipid pathway metabolites, energy pathway metabolites, brain osmolytes, amino acid neurotransmitters, and the antioxidant homocarnosine. These correlations were often brain region-specific. Revealing relationships between lutein and metabolic pathways may help identify potential candidates on which to complete further analyses and may shed light on important roles of lutein in the human brain during development.

  15. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    DEFF Research Database (Denmark)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

    2013-01-01

    magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified...... reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first...

  16. Neural associations of the early retinotopic cortex with the lateral occipital complex during visual perception.

    Directory of Open Access Journals (Sweden)

    Delong Zhang

    Full Text Available Previous studies have demonstrated that the early retinotopic cortex (ERC, i.e., V1/V2/V3 is highly associated with the lateral occipital complex (LOC during visual perception. However, it remains largely unclear how to evaluate their associations in quantitative way. The present study tried to apply a multivariate pattern analysis (MVPA to quantify the neural activity in ERC and its association with that of the LOC when participants saw visual images. To this end, we assessed whether low-level visual features (Gabor features could predict the neural activity in the ERC and LOC according to a voxel-based encoding model (VBEM, and then quantified the association of the neural activity between these regions by using an analogical VBEM. We found that the Gabor features remarkably predicted the activity of the ERC (e.g., the predicted accuracy was 52.5% for a participant instead of that of the LOC (4.2%. Moreover, the MVPA approach can also be used to establish corresponding relationships between the activity patterns in the LOC and those in the ERC (64.2%. In particular, we found that the integration of the Gabor features and LOC visual information could dramatically improve the 'prediction' of ERC activity (88.3%. Overall, the present study provides new evidences for the possibility of quantifying the association of the neural activity between the regions of ERC and LOC. This approach will help to provide further insights into the neural substrates of the visual processing.

  17. Synaptic proteome changes in the superior frontal gyrus and occipital cortex of the alcoholic brain.

    Science.gov (United States)

    Etheridge, Naomi; Lewohl, Joanne M; Mayfield, R Dayne; Harris, R Adron; Dodd, Peter R

    2009-06-24

    Cognitive deficits and behavioral changes that result from chronic alcohol abuse are a consequence of neuropathological changes which alter signal transmission through the neural network. To focus on the changes that occur at the point of connection between the neural network cells, synaptosomal preparations from post-mortem human brain of six chronic alcoholics and six non-alcoholic controls were compared using 2D-DIGE. Functionally affected and spared regions (superior frontal gyrus, SFG, and occipital cortex, OC, respectively) were analyzed from both groups to further investigate the specific pathological response that alcoholism has on the brain. Forty-nine proteins were differentially regulated between the SFG of alcoholics and the SFG of controls and 94 proteins were regulated in the OC with an overlap of 23 proteins. Additionally, the SFG was compared to the OC within each group (alcoholics or controls) to identify region specific differences. A selection were identified by MALDI-TOF mass spectrometry revealing proteins involved in vesicle transport, metabolism, folding and trafficking, and signal transduction, all of which have the potential to influence synaptic activity. A number of proteins identified in this study have been previously related to alcoholism; however, the focus on synaptic proteins has also uncovered novel alcoholism-affected proteins. Further exploration of these proteins will illuminate the mechanisms altering synaptic plasticity, and thus neuronal signaling and response, in the alcoholic brain.

  18. Diabetic brain or retina? Visual psychophysical performance in diabetic patients in relation to GABA levels in occipital cortex.

    Science.gov (United States)

    Sanches, Mafalda; Abuhaiba, Sulaiman I; d'Almeida, Otília C; Quendera, Bruno; Gomes, Leonor; Moreno, Carolina; Guelho, Daniela; Castelo-Branco, Miguel

    2017-06-01

    Visual impairment is one of the most feared complications of Type 2 Diabetes Mellitus. Here, we aimed to investigate the role of occipital cortex γ-aminobutyric acid (GABA) as a predictor of visual performance in type 2 diabetes. 18 type 2 diabetes patients were included in a longitudinal prospective one-year study, as well as 22 healthy age-matched controls. We collected demographic data, HbA1C and used a novel set of visual psychophysical tests addressing color, achromatic luminance and speed discrimination in both groups. Psychophysical tests underwent dimension reduction with principle component analysis into three synthetic variables: speed, achromatic luminance and color discrimination. A MEGA-PRESS magnetic resonance brain spectroscopy sequence was used to measure occipital GABA levels in the type 2 diabetes group. Retinopathy grading and retinal microaneurysms counting were performed in the type 2 diabetes group for single-armed correlations. Speed discrimination thresholds were significantly higher in the type 2 diabetes group in both visits; mean difference (95% confidence interval), [0.86 (0.32-1.40) in the first visit, 0.74 (0.04-1.44) in the second visit]. GABA from the occipital cortex predicted speed and achromatic luminance discrimination thresholds within the same visit (r = 0.54 and 0.52; p = 0.02 and 0.03, respectively) in type 2 diabetes group. GABA from the occipital cortex also predicted speed discrimination thresholds one year later (r = 0.52; p = 0.03) in the type 2 diabetes group. Our results suggest that speed discrimination is impaired in type 2 diabetes and that occipital cortical GABA is a novel predictor of visual psychophysical performance independently from retinopathy grade, metabolic control or disease duration in the early stages of the disease.

  19. Differential involvement of left prefrontal cortex in inductive and deductive reasoning.

    Science.gov (United States)

    Goel, Vinod; Dolan, Raymond J

    2004-10-01

    While inductive and deductive reasoning are considered distinct logical and psychological processes, little is known about their respective neural basis. To address this issue we scanned 16 subjects with fMRI, using an event-related design, while they engaged in inductive and deductive reasoning tasks. Both types of reasoning were characterized by activation of left lateral prefrontal and bilateral dorsal frontal, parietal, and occipital cortices. Neural responses unique to each type of reasoning determined from the Reasoning Type (deduction and induction) by Task (reasoning and baseline) interaction indicated greater involvement of left inferior frontal gyrus (BA 44) in deduction than induction, while left dorsolateral (BA 8/9) prefrontal gyrus showed greater activity during induction than deduction. This pattern suggests a dissociation within prefrontal cortex for deductive and inductive reasoning.

  20. The Visual Word Form Area remains in the dominant hemisphere for language in late-onset left occipital lobe epilepsies: A postsurgery analysis of two cases.

    Science.gov (United States)

    Lopes, Ricardo; Nunes, Rita Gouveia; Simões, Mário Rodrigues; Secca, Mário Forjaz; Leal, Alberto

    2015-05-01

    Automatic recognition of words from letter strings is a critical processing step in reading that is lateralized to the left-hemisphere middle fusiform gyrus in the so-called Visual Word Form Area (VWFA). Surgical lesions in this location can lead to irreversible alexia. Very early left hemispheric lesions can lead to transfer of the VWFA to the nondominant hemisphere, but it is currently unknown if this capability is preserved in epilepsies developing after reading acquisition. In this study, we aimed to determine the lateralization of the VWFA in late-onset left inferior occipital lobe epilepsies and also the effect of surgical disconnection from the adjacent secondary visual areas. Two patients with focal epilepsies with onset near the VWFA underwent to surgery for epilepsy, with sparing of this area. Neuropsychology evaluations were performed before and after surgery, as well as quantitative evaluation of the speed of word reading. Comparison of the surgical localization of the lesion, with the BOLD activation associated with the contrast of words-strings, was performed, as well as a study of the associated main white fiber pathways using diffusion-weighted imaging. Neither of the patients developed alexia after surgery (similar word reading speed before and after surgery) despite the fact that the inferior occipital surgical lesions reached the neighborhood (less than 1cm) of the VWFA. Surgeries partly disconnected the VWFA from left secondary visual areas, suggesting that pathways connecting to the posterior visual ventral stream were severely affected but did not induce alexia. The anterior and superior limits of the resection suggest that the critical connection between the VWFA and the Wernicke's Angular Gyrus cortex was not affected, which is supported by the detection of this tract with probabilistic tractography. Left occipital lobe epilepsies developing after reading acquisition did not produce atypical localizations of the VWFA, even with foci in the

  1. Effect of luminance contrast on BOLD-fMRI response in deaf and normal occipital visual cortex

    International Nuclear Information System (INIS)

    Xue Yanping; Zhai Renyou; Jiang Tao; Cui Yong; Zhou Tiangang; Rao Hengyi; Zhuo Yan

    2002-01-01

    Objective: To examine the effect of luminance contrast stimulus by using blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) within deaf occipital visual cortex, and to compare the distribution, extent, and intensity of activated areas between deaf subjects and normal hearing subjects. Methods: Twelve deaf subjects (average age 16.5) and 15 normal hearing subjects (average age 23.7) were stimulated by 4 kinds of luminance contrast (0.7, 2.2, 50.0, 180.0 lm). The fMRI data were collected on GE 1.5 T Signa Horizon LX MRI system and analyzed by AFNI to generate the activation map. Results: Responding to all 4 kinds of stimulus luminance contrast, all deaf and normal subjects showed significant activations in occipital visual cortex. For both deaf and normal subjects, the number of activated pixels increased significantly with increasing luminance contrast (F normal = 4.27, P deaf = 6.41, P 0.05). The local mean activation level for all activated pixels remained constant with increasing luminance contrast. However, there was an increase in the mean activation level for those activated pixels common to all trials as the stimulus luminance contrast was increased, but no significant difference was found within them (F normal = 0.79, P > 0.05; F deaf = 1.6, P > 0.05). Conclusion: The effect of luminance contrast on occipital visual cortex of deaf is similar to but somewhat higher than that of normal hearing subjects. In addition, it also proved that fMRI is a feasible method in the study of the deaf visual cortex

  2. Working memory training in congenitally blind individuals results in an integration of occipital cortex in functional networks.

    Science.gov (United States)

    Gudi-Mindermann, Helene; Rimmele, Johanna M; Nolte, Guido; Bruns, Patrick; Engel, Andreas K; Röder, Brigitte

    2018-08-01

    The functional relevance of crossmodal activation (e.g. auditory activation of occipital brain regions) in congenitally blind individuals is still not fully understood. The present study tested whether the occipital cortex of blind individuals is integrated into a challenged functional network. A working memory (WM) training over four sessions was implemented. Congenitally blind and matched sighted participants were adaptively trained with an n-back task employing either voices (auditory training) or tactile stimuli (tactile training). In addition, a minimally demanding 1-back task served as an active control condition. Power and functional connectivity of EEG activity evolving during the maintenance period of an auditory 2-back task were analyzed, run prior to and after the WM training. Modality-specific (following auditory training) and modality-independent WM training effects (following both auditory and tactile training) were assessed. Improvements in auditory WM were observed in all groups, and blind and sighted individuals did not differ in training gains. Auditory and tactile training of sighted participants led, relative to the active control group, to an increase in fronto-parietal theta-band power, suggesting a training-induced strengthening of the existing modality-independent WM network. No power effects were observed in the blind. Rather, after auditory training the blind showed a decrease in theta-band connectivity between central, parietal, and occipital electrodes compared to the blind tactile training and active control groups. Furthermore, in the blind auditory training increased beta-band connectivity between fronto-parietal, central and occipital electrodes. In the congenitally blind, these findings suggest a stronger integration of occipital areas into the auditory WM network. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

    Science.gov (United States)

    Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

    2014-01-01

    Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

  4. The cognitive profile of occipital lobe epilepsy and the selective association of left temporal lobe hypometabolism with verbal memory impairment.

    Science.gov (United States)

    Knopman, Alex A; Wong, Chong H; Stevenson, Richard J; Homewood, Judi; Mohamed, Armin; Somerville, Ernest; Eberl, Stefan; Wen, Lingfeng; Fulham, Michael; Bleasel, Andrew F

    2014-08-01

    We investigated the cognitive profile of structural occipital lobe epilepsy (OLE) and whether verbal memory impairment is selectively associated with left temporal lobe hypometabolism on [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET). Nine patients with OLE, ages 8-29 years, completed presurgical neuropsychological assessment. Composite measures were calculated for intelligence quotient (IQ), speed, attention, verbal memory, nonverbal memory, and executive functioning. In addition, the Wisconsin Card Sorting Test (WCST) was used as a specific measure of frontal lobe functioning. Presurgical FDG-PET was analyzed with statistical parametric mapping in 8 patients relative to 16 healthy volunteers. Mild impairments were evident for IQ, speed, attention, and executive functioning. Four patients demonstrated moderate or severe verbal memory impairment. Temporal lobe hypometabolism was found in seven of eight patients. Poorer verbal memory was associated with left temporal lobe hypometabolism (p = 0.002), which was stronger (p = 0.03 and p = 0.005, respectively) than the association of left temporal lobe hypometabolism with executive functioning or with performance on the WCST. OLE is associated with widespread cognitive comorbidity, suggesting cortical dysfunction beyond the occipital lobe. Verbal memory impairment is selectively associated with left temporal lobe hypometabolism in OLE, supporting a link between neuropsychological dysfunction and remote hypometabolism in focal epilepsy. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

  5. Alfred Walter Campbell and the visual functions of the occipital cortex.

    Science.gov (United States)

    Macmillan, Malcolm

    2014-07-01

    In his pioneering cytoarchitectonic studies of the human brain, Alfred Walter Campbell identified two structurally different areas in the occipital lobes and assigned two different kinds of visual functions to them. The first area, the visuosensory, was essentially on the mesial surface of the calcarine fissure. It was the terminus of nervous impulses generated in the retina and was where simple visual sensations arose. The second area, the visuopsychic, which surrounded or invested the first, was where sensations were interpreted and elaborated into visual perceptions. I argue that Campbell's distinction between the two areas was the starting point for the eventual differentiation of areas V1-V5. After a brief outline of Campbell's early life and education in Australia and of his Scottish medical education and early work as a pathologist at the Lancashire County Lunatic Asylum at Rainhill near Liverpool, I summarise his work on the human brain. In describing the structures he identified in the occipital lobes, I analyse the similarities and differences between them and the related structures identified by Joseph Shaw Bolton. I conclude by proposing some reasons for how that work came to be overshadowed by the later studies of Brodmann and for the more general lack of recognition given Campbell and his work. Those reasons include the effect of the controversies precipitated by Campbell's alliance with Charles Sherrington over the functions of the sensory and motor cortices. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Anodal-tDCS over the human right occipital cortex enhances the perception and memory of both faces and objects.

    Science.gov (United States)

    Barbieri, Marica; Negrini, Marcello; Nitsche, Michael A; Rivolta, Davide

    2016-01-29

    Accurate face processing skills are pivotal for typical social cognition, and impairments in this ability characterise various clinical conditions (e.g., prosopagnosia). No study to date has investigated whether transcranial direct current stimulation (tDCS) can causally enhance face processing. In addition, the category- and the process-specificity of tDCS effects, as well as the role of the timing of neuromodulation with respect to the execution of cognitive tasks are still unknown. In this single-blind, sham-controlled study, we examined whether the administration of anodal-tDCS (a-tDCS) over the right occipital cortex of healthy volunteers (N=64) enhances performance on perceptual and memory tasks involving both face and object stimuli. Neuromodulation was delivered in two conditions: online (a-tDCS during task execution) and offline (a-tDCS before task execution). The results demonstrate that offline a-tDCS enhances the perception and memory performance of both faces and objects. There was no effect of online a-tDCS on behaviour. Furthermore, the offline effect was site-specific since a-tDCS over the sensory-motor cortex did not lead to behavioural changes. Our results add relevant information about the breadth of cognitive processes and visual stimuli that can be modulated by tDCS, and about the design of effective neuromodulation protocols, which have implications for advancing theories in cognitive neuroscience and clinical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Development of neuropeptide Y (NPY) immunoreactive neurons in the rat occipital cortex: A combined immunohistochemical-autoradiographic study

    International Nuclear Information System (INIS)

    Cavanagh, M.E.; Parnavelas, J.G.

    1990-01-01

    The postnatal development of neuropeptide Y (NPY)-immunoreactive neurons, previously labeled with [3H]thymidine on embryonic days E14-E21, has been studied in the rat occipital cortex. Immunohistochemistry combined with autoradiography showed evidence of a modified inside-out pattern of maturation. NPY-neurons are generated between E14 and E20 and are found in layers II-VI of the cortex and the subcortical white matter. NPY neurons from all these birthdates are overproduced at first, although cells generated at E16 produce the greatest excess, followed by E15 and E17. Some of these transient neurons are found in the wrong layer for their birthdates, and their elimination produces a more correct alignment at maturity. However, most of the NPY neurons that survive are generated at E17, and these cells are found throughout layers II-VI with a preponderance in layer VI. This evidence is strongly suggestive of cell death rather than merely cessation of production of NPY

  8. Transient contribution of left posterior parietal cortex to cognitive restructuring.

    Science.gov (United States)

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-03-17

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring.

  9. Hyperfamiliarity for unknown faces after left lateral temporo-occipital venous infarction: a double dissociation with prosopagnosia.

    Science.gov (United States)

    Vuilleumier, Patrik; Mohr, Christine; Valenza, Nathalie; Wetzel, Corinne; Landis, Theodor

    2003-04-01

    Right hemisphere dominance in face processing is well established and unilateral right inferior temporo-occipital damage can result in prosopagnosia. Here, we describe a 21-year-old right-handed woman with acute impairment in face recognition that selectively concerned unfamiliar faces, following a focal left lateral temporo-occipital venous infarct. She was severely impaired in discerning that unknown people seen in everyday life were unfamiliar, although she had no difficulty recognizing familiar people. Thus, she had no prosopagnosia, but abnormal 'hyperfamiliarity' for unknown faces. Her difficulty was not accompanied by delusions or deficits in discrimination, identification or memory for faces. Standard neuropsychological testing showed that her recognition of familiar faces was entirely normal. By contrast, her sense of personally knowing faces was severely impaired when unknown faces evoked weak signals of familiarity based on spurious cues, to the extent that she would misattribute fame to faces that were unknown but to which she had been incidentally exposed on a prior occasion. Priming experiments also revealed that, unlike normal subjects, she made familiarity judgements without accessing semantic identity representations. Moreover, in face recognition tests, she generally showed bias in that she relied more on right-hemisphere strategies to identify global traits and less on left-hemisphere processes compared with healthy subjects. This case provides novel evidence for a differential contribution of the two hemispheres to face recognition. Hyperfamiliarity for unknown faces might arise from an imbalance between reciprocal hemispheric functions in face recognition, with relative hypoactivation of left hemisphere processes but hyperactivation of right-hemisphere processes for retrieving stored associations about people, linking seen faces to representations of affective and personal relevance. Hence, abnormal bias in attributing some personal meaning to

  10. Activity in the lateral occipital cortex between 200 and 300 ms distinguishes between physically identical seen and unseen stimuli

    Directory of Open Access Journals (Sweden)

    Ying eLiu

    2012-07-01

    Full Text Available There is converging evidence that electrophysiological responses over posterior cortical regions in the 200-300 ms range distinguish between physically identical stimuli that reach consciousness or remain unseen. Here, we attempt at determining the sources of this awareness-related activity using MEG. Fourteen subjects were presented with faint colored gratings at threshold for contrast and reported on each trial whether the grating was seen or unseen. Subjects were primed with a color cue that could be congruent or incongruent with the color of the grating, to probe to what extent two co-localized features (color and orientation would be bound in consciousness. The contrast between neural responses to seen and unseen physically identical gratings revealed a sustained posterior difference between 190 and 350 ms, thereby replicating prior studies. We further show that the main sources of the awareness-related activity were localized bilaterally on the lateral convexity of the occipito-temporal region, in the lateral occipital (LO complex, as well as in the right posterior infero-temporal region. No activity differentiating seen and unseen trials could be observed in frontal or parietal regions in this latency range, even at lower threshold. Color congruency did not improve gratings' detection, and the awareness-related activity was independent from color congruency. However, at the neural level, color congruency was processed differently in grating-present and grating-absent trials. The pattern of results suggests the existence of a neural process of color congruency engaging left parietal regions that is affected by the mere presence of another feature, whether this feature reaches consciousness or not. Altogether, our results reveal an occipital source of visual awareness insensitive to color congruency, and a simultaneous parietal source not engaged in visual awareness, but sensitive to the manipulation of co-localized features.

  11. Cytoarchitecture of the human lateral occipital cortex: mapping of two extrastriate areas hOc4la and hOc4lp.

    Science.gov (United States)

    Malikovic, Aleksandar; Amunts, Katrin; Schleicher, Axel; Mohlberg, Hartmut; Kujovic, Milenko; Palomero-Gallagher, Nicola; Eickhoff, Simon B; Zilles, Karl

    2016-05-01

    The microstructural correlates of the functional segregation of the human lateral occipital cortex are largely unknown. Therefore, we analyzed the cytoarchitecture of this region in ten human post-mortem brains using an observer-independent and statistically testable parcellation method to define the position and extent of areas in the lateral occipital cortex. Two new cytoarchitectonic areas were found: an anterior area hOc4la and a posterior area hOc4lp. hOc4la was located behind the anterior occipital sulcus in rostral and ventral portions of this region where it occupies the anterior third of the middle and inferior lateral occipital gyri. hOc4lp was found in caudal and dorsal portions of this region where it extends along the superior and middle lateral occipital gyri. The cytoarchitectonic areas were registered to 3D reconstructions of the corresponding brains, which were subsequently spatially normalized to the Montreal Neurological Institute reference space. Continuous probabilistic maps of both areas based on the analysis of ten brains were generated to characterize their inter-subject variability in location and size. The maps of hOc4la and hOc4lp were then used as seeds for meta-analytic connectivity modeling and quantitative functional decoding to identify their co-activation patterns and assignment to functional domains. Convergent evidence from their location, topography, size, functional domains and connectivity indicates that hOc4la and hOc4lp are the potential anatomical correlates of the functionally defined lateral occipital areas LO-1 and LO-2.

  12. Effects of post-traumatic stress disorder on occipital lobe function and structure.

    Science.gov (United States)

    Chao, Linda L; Lenoci, Maryann; Neylan, Thomas C

    2012-05-09

    Although there is evidence for strong connectivity between the amygdala and the visual cortex and some evidence for reduced occipital lobe gray matter volume in patients with post-traumatic stress disorder (PTSD), few studies have directly examined the effects of PTSD on occipital function. The current study used functional and structural MRI to examine occipital cortex function and structure in male combat veterans with and without PTSD. Left occipital gray matter volume was reduced in PTSD patients relative to the controls and correlated negatively with the severity of PTSD symptoms. Functional activity in the lateral occipital complex to aversive and nonaversive pictures presented in novel and repeated presentations was not altered by PTSD. These findings suggest that PTSD adversely affects occipital lobe volume but not the reactivity of the lateral occipital complex to generally aversive, trauma nonspecific stimuli.

  13. OCCIPITAL LOBE SYNDROME

    OpenAIRE

    Shahdevi Nandar Kurniawan

    2016-01-01

    The ability to recognize objects and words is not just depend on the integrity of visual pathway and primary vision area on cerebral cortex (Brodmann area 17), but also secondary vision area 18 and tertiary vision area 19 on occipital lobe. Lesion in occipital lobe could disturb of human visual function such as visual field defects, inability to recognize colors, inability to recognize words, visual hallucinations and illusions, occipital lobe epilepsy, and Anton’s syndrome. Some causes of oc...

  14. Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD-2300 specimen.

    Science.gov (United States)

    García-Tabernero, Antonio; Peña-Melián, Angel; Rosas, Antonio

    2018-07-01

    The comparative analysis of the endocranial surface of the El Sidrón new occipital fragment SD-2300 shows meaningful differences in the configuration of the occipital pole region between neandertals and anatomically modern humans (AMH). The particular asymmetries found in neandertals in the venous sinus drainage and the petalial patterns are recognizable in this new specimen as well. In addition, the supra- and infracalcarine fossae of the occipital pole region appear to deviate obliquely from the mid-line when compared with sapiens. Due to the excellent preservation conditions of SD-2300, the main sulci and gyri of the occipital pole area have been identified, this degree of detail being uncommon in a fossil specimen; in general, the gyrification pattern is similar to AMH, but with some notable differences. Particularly interesting is the description of the lunate and the calcarine sulci. The lunate sulcus is located close to the occipital pole, in a similar posterior position to in other Homo species. Regarding the calcarine sulcus, there are significant differences in the primary visual cortex, with the V1 area, or Brodmann area 17, being larger in Homo neanderthalensis than in Homo sapiens. This may lead to greater visual acuity in neandertals than in sapiens. © 2018 Anatomical Society.

  15. Human left ventral premotor cortex mediates matching of hand posture to object use.

    Directory of Open Access Journals (Sweden)

    Guy Vingerhoets

    Full Text Available Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP has been identified as the anterior part of the intraparietal sulcus (aIPS, whereas the putative human equivalent of the monkey frontal region (F5 is located in the ventral part of the premotor cortex (vPMC. Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS, the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA 44. We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands.

  16. Photoreactivity of the occipital cortex measured by functional magnetic resonance imaging-blood oxygenation level dependent in migraine patients and healthy volunteers: pathophysiological implications.

    Science.gov (United States)

    Martín, Helena; Sánchez del Río, Margarita; de Silanes, Carlos López; Álvarez-Linera, Juan; Hernández, Juan Antonio; Pareja, Juan A

    2011-01-01

    The brain of migraineurs is hyperexcitable, particularly the occipital cortex, which is probably hypersensitive to light. Photophobia or hypersensitivity to light may be accounted for by an increased excitability of trigeminal, the visual pathways, and the occipital cortex. To study light sensitivity and photophobia by assessing the response to light stimuli with functional magnetic resonance imaging-blood oxygenation level dependent (fMRI-BOLD) of the occipital cortex in migraineurs and in controls. Also, to try to decipher the contribution of the occipital cortex to photophobia and whether the cortical reactivity of migraineurs may be part of a constitutional (defensive) mechanism or represents an acquired (sensitization) phenomenon. Nineteen patients with migraine (7 with aura and 12 without aura) and 19 controls were studied with fMRI-BOLD during 4 increasing light intensities. Eight axial image sections of 0.5 cm that covered the occipital cortex were acquired for each intensity. We measured the extension and the intensity of activation for every light stimuli. Photophobia was estimated according to a 0 to 3 semiquantitative scale of light discomfort. Migraineurs had a significantly higher number of fMRI-activated voxels at low (320.4 for migraineurs [SD = 253.9] and 164.3 for controls [SD = 102.7], P = .027) and medium-low luminance levels (501.2 for migraineurs [SD = 279.5] and 331.1 for controls [SD = 194.3], P = .034) but not at medium-high (579.5 for migraineurs [SD = 201.4] and 510.2 for controls [SD = 239.5], P = .410) and high light stimuli (496.2 for migraineurs [SD = 216.2] and 394.7 for controls [SD = 240], P = .210). No differences were found with respect to the voxel activation intensity (amplitude of the BOLD wave) between migraineurs and controls (8.98 [SD = 2.58] vs 7.99 [SD = 2.57], P = .25; 10.82 [SD = 3.27] vs 9.81 [SD = 3.19], P = .31; 11.90 [SD = 3.18] vs 11.06 [SD = 2.56], P = .62; 11.45 [SD = 2.65] vs 10.25 [SD = 2.22], P = .16). Light

  17. Subcomponents and connectivity of the inferior fronto-occipital fasciculus revealed by diffusion spectrum imaging fiber tracking

    Directory of Open Access Journals (Sweden)

    Yupeng Wu

    2016-09-01

    Full Text Available The definitive structure and functional role of the inferior fronto-occipital fasciculus (IFOF are still controversial. In this study, we aimed to investigate the connectivity, asymmetry and segmentation patterns of this bundle. High angular diffusion spectrum imaging (DSI analysis was performed on ten healthy adults and a 90-subject DSI template (NTU-90 Atlas. In addition, a new tractography approach based on the anatomic subregions and two regions of interest (ROI was evaluated for the fiber reconstructions. More widespread anterior-posterior connections than previous standard definition of the IFOF were found. This distinct pathway demonstrated a greater inter-subjects connective variability with a maximum of 40% overlap in its central part. The statistical results revealed no asymmetry between the left and right hemispheres and no significant differences existed in distributions of the IFOF according to sex. In addition, five subcomponents within the IFOF were identified according to the frontal areas of originations. As the subcomponents passed through the anterior floor of the external capsule, the fibers radiated to the posterior terminations. The most common connection patterns of the subcomponents were as follows: IFOF-I, from frontal polar cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe and pericalcarine; IFOF-II, from orbito-frontal cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe and pericalcarine; IFOF-III, from inferior frontal gyrus to inferior occipital lobe, middle occipital lobe, superior occipital lobe, occipital pole and pericalcarine; IFOF-IV, from middle frontal gyrus to occipital pole and inferior occipital lobe; IFOF-V, from superior frontal gyrus to occipital pole, inferior occipital lobe and middle occipital lobe. Our work demonstrates the feasibility of high resolution diffusion tensor tractography with sufficient

  18. Subcomponents and Connectivity of the Inferior Fronto-Occipital Fasciculus Revealed by Diffusion Spectrum Imaging Fiber Tracking.

    Science.gov (United States)

    Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao

    2016-01-01

    The definitive structure and functional role of the inferior fronto-occipital fasciculus (IFOF) are still controversial. In this study, we aimed to investigate the connectivity, asymmetry, and segmentation patterns of this bundle. High angular diffusion spectrum imaging (DSI) analysis was performed on 10 healthy adults and a 90-subject DSI template (NTU-90 Atlas). In addition, a new tractography approach based on the anatomic subregions and two regions of interest (ROI) was evaluated for the fiber reconstructions. More widespread anterior-posterior connections than previous "standard" definition of the IFOF were found. This distinct pathway demonstrated a greater inter-subjects connective variability with a maximum of 40% overlap in its central part. The statistical results revealed no asymmetry between the left and right hemispheres and no significant differences existed in distributions of the IFOF according to sex. In addition, five subcomponents within the IFOF were identified according to the frontal areas of originations. As the subcomponents passed through the anterior floor of the external capsule, the fibers radiated to the posterior terminations. The most common connection patterns of the subcomponents were as follows: IFOF-I, from frontal polar cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-II, from orbito-frontal cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-III, from inferior frontal gyrus to inferior occipital lobe, middle occipital lobe, superior occipital lobe, occipital pole, and pericalcarine; IFOF-IV, from middle frontal gyrus to occipital pole, and inferior occipital lobe; IFOF-V, from superior frontal gyrus to occipital pole, inferior occipital lobe, and middle occipital lobe. Our work demonstrates the feasibility of high resolution diffusion tensor tractography with sufficient sensitivity to

  19. Subcomponents and Connectivity of the Inferior Fronto-Occipital Fasciculus Revealed by Diffusion Spectrum Imaging Fiber Tracking

    Science.gov (United States)

    Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao

    2016-01-01

    The definitive structure and functional role of the inferior fronto-occipital fasciculus (IFOF) are still controversial. In this study, we aimed to investigate the connectivity, asymmetry, and segmentation patterns of this bundle. High angular diffusion spectrum imaging (DSI) analysis was performed on 10 healthy adults and a 90-subject DSI template (NTU-90 Atlas). In addition, a new tractography approach based on the anatomic subregions and two regions of interest (ROI) was evaluated for the fiber reconstructions. More widespread anterior-posterior connections than previous “standard” definition of the IFOF were found. This distinct pathway demonstrated a greater inter-subjects connective variability with a maximum of 40% overlap in its central part. The statistical results revealed no asymmetry between the left and right hemispheres and no significant differences existed in distributions of the IFOF according to sex. In addition, five subcomponents within the IFOF were identified according to the frontal areas of originations. As the subcomponents passed through the anterior floor of the external capsule, the fibers radiated to the posterior terminations. The most common connection patterns of the subcomponents were as follows: IFOF-I, from frontal polar cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-II, from orbito-frontal cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-III, from inferior frontal gyrus to inferior occipital lobe, middle occipital lobe, superior occipital lobe, occipital pole, and pericalcarine; IFOF-IV, from middle frontal gyrus to occipital pole, and inferior occipital lobe; IFOF-V, from superior frontal gyrus to occipital pole, inferior occipital lobe, and middle occipital lobe. Our work demonstrates the feasibility of high resolution diffusion tensor tractography with sufficient sensitivity

  20. Using fNIRS to Examine Occipital and Temporal Responses to Stimulus Repetition in Young Infants: Evidence of Selective Frontal Cortex Involvement

    Science.gov (United States)

    Emberson, Lauren L.; Cannon, Grace; Palmeri, Holly; Richards, John E.; Aslin, Richard N.

    2016-01-01

    How does the developing brain respond to recent experience? Repetition suppression (RS) is a robust and well-characterized response of to recent experience found, predominantly, in the perceptual cortices of the adult brain. We use functional near-infrared spectroscopy (fNIRS) to investigate how perceptual (temporal and occipital) and frontal cortices in the infant brain respond to auditory and visual stimulus repetitions (spoken words and faces). In Experiment 1, we find strong evidence of repetition suppression in the frontal cortex but only for auditory stimuli. In perceptual cortices, we find only suggestive evidence of auditory RS in the temporal cortex and no evidence of visual RS in any ROI. In Experiments 2 and 3, we replicate and extend these findings. Overall, we provide the first evidence that infant and adult brains respond differently to stimulus repetition. We suggest that the frontal lobe may support the development of RS in perceptual cortices. PMID:28012401

  1. Hemifacial Pain and Hemisensory Disturbance Referred from Occipital Neuralgia Caused by Pathological Vascular Contact of the Greater Occipital Nerve

    OpenAIRE

    Son, Byung-chul; Choi, Jin-gyu

    2017-01-01

    Here we report a unique case of chronic occipital neuralgia caused by pathological vascular contact of the left greater occipital nerve. After 12 months of left-sided, unremitting occipital neuralgia, a hypesthesia and facial pain developed in the left hemiface. The decompression of the left greater occipital nerve from pathological contacts with the occipital artery resulted in immediate relief for hemifacial sensory change and facial pain, as well as chronic occipital neuralgia. Although re...

  2. Modulation of left primary motor cortex excitability after bimanual training and intermittent theta burst stimulation to left dorsal premotor cortex.

    Science.gov (United States)

    Neva, Jason L; Vesia, Michael; Singh, Amaya M; Staines, W Richard

    2014-03-15

    Bimanual visuomotor movement training (BMT) enhances the excitability of human preparatory premotor and primary motor (M1) cortices compared to unimanual movement. This occurs when BMT involves mirror symmetrical movements of both upper-limbs (in-phase) but not with non-symmetrical movements (anti-phase). The neural mechanisms mediating the effect of BMT is unclear, but may involve interhemispheric connections between homologous M1 representations as well as the dorsal premotor cortices (PMd). The purpose of this study is to assess how intermittent theta burst stimulation (iTBS) of the left PMd affects left M1 excitability, and the possible combined effects of iTBS to left PMd applied before a single session of BMT. Left M1 excitability was quantified using transcranial magnetic stimulation (TMS) in terms of both the amplitudes and spatial extent of motor evoked potentials (MEPs) for the extensor carpi radialis (ECR) before and multiple time points following (1) BMT, (2) iTBS to left PMd or (3) iTBS to left PMd and BMT. Although there was not a greater increase in either specific measure of M1 excitability due to the combination of the interventions, iTBS applied before BMT showed that both the spatial extent and global MEP amplitude for the ECR became larger in parallel, whereas the spatial extent was enhanced with BMT alone and global MEP amplitude was enhanced with iTBS to left PMd alone. These results suggest that the modulation of rapid functional M1 excitability associated with BMT and iTBS of the left PMd could operate under related early markers of neuro-plastic mechanisms, which may be expressed in concurrent and distinct patterns of M1 excitability. Critically, this work may guide rehabilitation training and stimulation techniques that modulate cortical excitability after brain injury. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Study the left prefrontal cortex activity of Chinese children with dyslexia in phonological processing by NIRS

    Science.gov (United States)

    Zhang, Zhili; Li, Ting; Zheng, Yi; Luo, Qingming; Song, Ranran; Gong, Hui

    2006-02-01

    Developmental dyslexia, a kind of prevalent psychological disease, represents that dyslexic children have unexpected difficulties in phonological processing and recognition test of Chinese characters. Some functional imaging technologies, such as fMRI and PET, have been used to study the brain activities of the children with dyslexia whose first language is English. In this paper, a portable, 16-channel, continuous-wave (CW) NIRS instrument was used to monitor the concentration changes of each hemoglobin species when Chinese children did the task of phonological processing and recognition test. The NIRS recorded the hemodynamic changes in the left prefrontal cortex of the children. 20 dyslexia-reading children (10~12 years old) and 20 normal-reading children took part in the phonological processing of Chinese characters including the phonological awareness section and the phonological decoding section. During the phonological awareness section, the changed concentration of deoxy-hemoglobin in dyslexia-reading children were significantly higher (p<0.05) than normal-reading children in the left ventrolateral prefrontal cortex (VLPFC). While in the phonological decoding section, both normal and dyslexic reading children had more activity in the left VLPFC, but only normal-reading children had activity in the left middorsal prefrontal cortex. In conclusion, both dyslexic and normal-reading children have activity in the left prefrontal cortex, but the degree and the areas of the prefrontal cortex activity are different between them when they did phonological processing.

  4. Changes in cytochrome-oxidase oxidation in the occipital cortex during visual simulation: improvement in sensitivity by the determination of the wavelength dependence of the differential pathlength

    Science.gov (United States)

    Kohl-Bareis, Matthias; Nolte, Christian; Heekeren, Hauke R.; Horst, Susanne; Scholz, J.; Obrig, Hellmuth; Villringer, Arno

    1998-01-01

    In this study we assess changes in the hemoglobin oxygenation (oxy-Hb, deoxy-Hb) and the Cytochrome-C-Oxidase redox state (Cyt-ox) in the occipital cortex during visual stimulation by near infrared spectroscopy. For the calculation of changes in oxy-Hb, deoxy-Hb and Cyt-ox from attenuation data via a modified Beer-Lambert equation, the wavelength dependence of the differential pathlength factor (DPF), i.e. the ratio of the mean optical pathlength and the physical light-source-detector separation, has to be taken into account. The wavelength dependence of the DPF determines the crosstalk between the different concentrations and is therefore essential for a high sensitivity. Here a simple method is suggested to estimate the wavelength dependence of the DPF((lambda) ) from pulse induced attenuation changes measured on the head of adult humans. The essence is that the DPF is the ratio of the attenuation changes over absorption coefficient changes and the spectral form of the pulse correlated absorption coefficient change is proportional to the extinction coefficient of blood. Indicators for the validity of the DPF((lambda) ) derived for wavelengths between 700 and 970 nm are the stability of the calculated oxy-Hb, deoxy-Hb and Cyt-ox signals with variations of the wavelength range included for their calculation and its overall agreement with the data available from the literature. The DPF derived from pulse measurements was used for the analysis of attenuation data from cortical stimulations. We show that Cyt-ox in the occipital cortex of human subjects is transiently oxidized during visual stimulation.

  5. Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

    Science.gov (United States)

    Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

    2015-02-01

    Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Intracerebral stimulation of left and right ventral temporal cortex during object naming.

    Science.gov (United States)

    Bédos Ulvin, Line; Jonas, Jacques; Brissart, Hélène; Colnat-Coulbois, Sophie; Thiriaux, Anne; Vignal, Jean-Pierre; Maillard, Louis

    2017-12-01

    While object naming is traditionally considered asa left hemisphere function, neuroimaging studies have reported activations related to naming in the ventral temporal cortex (VTC) bilaterally. Our aim was to use intracerebral electrical stimulation to specifically compare left and right VTC in naming. In twenty-three epileptic patients tested for visual object naming during stimulation, the proportion of naming impairments was significantly higher in the left than in the right VTC (31.3% vs 13.6%). The highest proportions of positive naming sites were found in the left fusiform gyrus and occipito-temporal sulcus (47.5% and 31.8%). For 17 positive left naming sites, an additional semantic picture matching was carried out, always successfully performed. Our results showed the enhanced role of the left compared to the right VTC in naming and suggest that it may be involved in lexical retrieval rather than in semantic processing. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Occipital GABA correlates with cognitive failures in daily life.

    Science.gov (United States)

    Sandberg, Kristian; Blicher, Jakob Udby; Dong, Mia Yuan; Rees, Geraint; Near, Jamie; Kanai, Ryota

    2014-02-15

    The brain has limited capacity, and so selective attention enhances relevant incoming information while suppressing irrelevant information. This process is not always successful, and the frequency of such cognitive failures varies to a large extent between individuals. Here we hypothesised that individual differences in cognitive failures might be reflected in inhibitory processing in the sensory cortex. To test this hypothesis, we measured GABA in human visual cortex using MR spectroscopy and found a negative correlation between occipital GABA (GABA+/Cr ratio) and cognitive failures as measured by an established cognitive failures questionnaire (CFQ). For a second site in parietal cortex, no correlation between CFQ score and GABA+/Cr ratio was found, thus establishing the regional specificity of the link between occipital GABA and cognitive failures. We further found that grey matter volume in the left superior parietal lobule (SPL) correlated with cognitive failures independently from the impact of occipital GABA and together, occipital GABA and SPL grey matter volume statistically explained around 50% of the individual variability in daily cognitive failures. We speculate that the amount of GABA in sensory areas may reflect the potential capacity to selectively suppress irrelevant information already at the sensory level, or alternatively that GABA influences the specificity of neural representations in visual cortex thus improving the effectiveness of successful attentional modulation. © 2013. Published by Elsevier Inc. All rights reserved.

  8. Early sensitivity of left perisylvian cortex to relationality in nouns and verbs.

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    Williams, Adina; Reddigari, Samir; Pylkkänen, Liina

    2017-06-01

    The ability to track the relationality of concepts, i.e., their capacity to encode a relationship between entities, is one of the core semantic abilities humans possess. In language processing, we systematically leverage this ability when computing verbal argument structure, in order to link participants to the events they participate in. Previous work has converged on a large region of left posterior perisylvian cortex as a locus for such processing, but the wide range of experimental stimuli and manipulations has yielded an unclear picture of the region's exact role(s). Importantly, there is a tendency for effects of relationality in single-word studies to localize to posterior temporo-parietal cortex, while argument structure effects in sentences appear in left superior temporal cortex. To characterize these sensitivities, we designed two MEG experiments that cross the factors relationality and eventivity. The first used minimal noun phrases and tested for an effect of semantic composition, while the second employed full sentences and a manipulation of grammatical category. The former identified a region of the left inferior parietal lobe sensitive to relationality, but not eventivity or combination, beginning at 170ms. The latter revealed a similarly-timed effect of relationality in left mid-superior temporal cortex, independent of eventivity and category. The results suggest that i) multiple sub-regions of perisylvian cortex are sensitive to the relationality carried by concepts even in the absence of arguments, ii) linguistic context modulates the locus of this sensitivity, consistent with prior studies, and iii) relationality information is accessed early - before 200ms - regardless of the concept's event status or syntactic category. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Joint Contribution of Left Dorsal Premotor Cortex and Supramarginal Gyrus to Rapid Action Reprogramming

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Siebner, Hartwig R

    2015-01-01

    human subjects performed a spatially-precued reaction time task. RESULTS: Relative to sham rTMS, effective online perturbation of left PMd significantly impaired both the response speed and accuracy in trials that were invalidly pre-cued and required the subject to reprogram the prepared action......BACKGROUND: The rapid adaptation of actions to changes in the environment is crucial for survival. We previously demonstrated a joint contribution of left dorsal premotor cortex (PMd) and left supramarginal gyrus (SMG) to action reprogramming. However, we did not probe the contribution of PMd...... to the speed and accuracy of action reprogramming and how the functional relevance of PMd changes in the presence of a dysfunctional SMG. OBJECTIVE: This study further dissociated the unique contribution of left PMd and SMG to action reprogramming. Specifically, we tested whether the critical contribution...

  10. Top-down and bottom-up influences on the left ventral occipito-temporal cortex during visual word recognition: an analysis of effective connectivity.

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    Schurz, Matthias; Kronbichler, Martin; Crone, Julia; Richlan, Fabio; Klackl, Johannes; Wimmer, Heinz

    2014-04-01

    The functional role of the left ventral occipito-temporal cortex (vOT) in visual word processing has been studied extensively. A prominent observation is higher activation for unfamiliar but pronounceable letter strings compared to regular words in this region. Some functional accounts have interpreted this finding as driven by top-down influences (e.g., Dehaene and Cohen [2011]: Trends Cogn Sci 15:254-262; Price and Devlin [2011]: Trends Cogn Sci 15:246-253), while others have suggested a difference in bottom-up processing (e.g., Glezer et al. [2009]: Neuron 62:199-204; Kronbichler et al. [2007]: J Cogn Neurosci 19:1584-1594). We used dynamic causal modeling for fMRI data to test bottom-up and top-down influences on the left vOT during visual processing of regular words and unfamiliar letter strings. Regular words (e.g., taxi) and unfamiliar letter strings of pseudohomophones (e.g., taksi) were presented in the context of a phonological lexical decision task (i.e., "Does the item sound like a word?"). We found no differences in top-down signaling, but a strong increase in bottom-up signaling from the occipital cortex to the left vOT for pseudohomophones compared to words. This finding can be linked to functional accounts which assume that the left vOT contains neurons tuned to complex orthographic features such as morphemes or words [e.g., Dehaene and Cohen [2011]: Trends Cogn Sci 15:254-262; Kronbichler et al. [2007]: J Cogn Neurosci 19:1584-1594]: For words, bottom-up signals converge onto a matching orthographic representation in the left vOT. For pseudohomophones, the propagated signals do not converge, but (partially) activate multiple orthographic word representations, reflected in increased effective connectivity. Copyright © 2013 Wiley Periodicals, Inc.

  11. Task-dependent modulation of regions in the left temporal cortex during auditory sentence comprehension.

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    Zhang, Linjun; Yue, Qiuhai; Zhang, Yang; Shu, Hua; Li, Ping

    2015-01-01

    Numerous studies have revealed the essential role of the left lateral temporal cortex in auditory sentence comprehension along with evidence of the functional specialization of the anterior and posterior temporal sub-areas. However, it is unclear whether task demands (e.g., active vs. passive listening) modulate the functional specificity of these sub-areas. In the present functional magnetic resonance imaging (fMRI) study, we addressed this issue by applying both independent component analysis (ICA) and general linear model (GLM) methods. Consistent with previous studies, intelligible sentences elicited greater activity in the left lateral temporal cortex relative to unintelligible sentences. Moreover, responses to intelligibility in the sub-regions were differentially modulated by task demands. While the overall activation patterns of the anterior and posterior superior temporal sulcus and middle temporal gyrus (STS/MTG) were equivalent during both passive and active tasks, a middle portion of the STS/MTG was found to be selectively activated only during the active task under a refined analysis of sub-regional contributions. Our results not only confirm the critical role of the left lateral temporal cortex in auditory sentence comprehension but further demonstrate that task demands modulate functional specialization of the anterior-middle-posterior temporal sub-areas. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving.

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    Noriyuki Oka

    Full Text Available In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves, but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS.The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task. Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections.Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05, but cerebral oxygen exchange increased significantly more during left curves (p < 0.05 in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05 only in the right frontal eye field.Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions.

  13. Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving

    Science.gov (United States)

    Oka, Noriyuki; Yoshino, Kayoko; Yamamoto, Kouji; Takahashi, Hideki; Li, Shuguang; Sugimachi, Toshiyuki; Nakano, Kimihiko; Suda, Yoshihiro; Kato, Toshinori

    2015-01-01

    Objectives In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves), but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS). Research Design and Methods The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task). Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections. Results Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05), but cerebral oxygen exchange increased significantly more during left curves (p right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p right frontal eye field. Conclusions Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions

  14. Focal epileptic seizures with secondary generalization in cortical atrophy and gliosis dysplasia in the left temporal lobe and hemimegalencephaly in the left occipital lobe

    International Nuclear Information System (INIS)

    Manchev, I.; Mancheva-Ganeva, V.; Manolova, T.; Manchev, L.

    2016-01-01

    It is a case of an eight-year-old patient with cortical dysplasia and gliosis in the left temporal lobe clinically manifested with focal epileptic seizures with secondary generalization. Signs of mental retardation and a number of somatic complications - diabetes, etc., were found. The complex therapy with anticonvulsant medications, immunovenin, plasmaphoresis and anti-diabetic drugs was partially effective

  15. Bilateral primary motor cortex circuitry is modulated due to theta burst stimulation to left dorsal premotor cortex and bimanual training.

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    Neva, Jason L; Vesia, Michael; Singh, Amaya M; Staines, W Richard

    2015-08-27

    Motor preparatory and execution activity is enhanced after a single session of bimanual visuomotor training (BMT). Recently, we have shown that increased primary motor cortex (M1) excitability occurs when BMT involves simultaneous activation of homologous muscles and these effects are enhanced when BMT is preceded by intermittent theta burst stimulation (iTBS) to the left dorsal premotor cortex (lPMd). The neural mechanisms underlying these modulations are unclear, but may include interhemispheric interactions between homologous M1s and connectivity with premotor regions. The purpose of this study was to investigate the possible intracortical and interhemispheric modulations of the extensor carpi radials (ECR) representation in M1 bilaterally due to: (1) BMT, (2) iTBS to lPMd, and (3) iTBS to lPMd followed by BMT. This study tests three related hypotheses: (1) BMT will enhance excitability within and between M1 bilaterally, (2) iTBS to lPMd will primarily enhance left M1 (lM1) excitability, and (3) the combination of these interventions will cause a greater enhancement of bilateral M1 excitability. We used single and paired-pulse transcranial magnetic stimulation (TMS) to quantify M1 circuitry bilaterally. The results demonstrate the neural mechanisms underlying the early markers of rapid functional plasticity associated with BMT and iTBS to lPMd primarily relate to modulations of long-interval inhibitory (i.e. GABAB-mediated) circuitry within and between M1s. This work provides novel insight into the underlying neural mechanisms involved in M1 excitability changes associated with BMT and iTBS to lPMd. Critically, this work may inform rehabilitation training and stimulation techniques that modulate cortical plasticity after brain injury. Copyright © 2015. Published by Elsevier B.V.

  16. Left auditory cortex is involved in pairwise comparisons of the direction of frequency modulated tones

    Directory of Open Access Journals (Sweden)

    Nicole eAngenstein

    2013-07-01

    Full Text Available Evaluating series of complex sounds like those in speech and music requires sequential comparisons to extract task-relevant relations between subsequent sounds. With the present functional magnetic resonance imaging (fMRI study, we investigated whether sequential comparison of a specific acoustic feature within pairs of tones leads to a change in lateralized processing in the auditory cortex of humans. For this we used the active categorization of the direction (up versus down of slow frequency modulated (FM tones. Several studies suggest that this task is mainly processed in the right auditory cortex. These studies, however, tested only the categorization of the FM direction of each individual tone. In the present study we ask the question whether the right lateralized processing changes when, in addition, the FM direction is compared within pairs of successive tones. For this we use an experimental approach involving contralateral noise presentation in order to explore the contributions made by the left and right auditory cortex in the completion of the auditory task. This method has already been applied to confirm the right-lateralized processing of the FM direction of individual tones. In the present study, the subjects were required to perform, in addition, a sequential comparison of the FM-direction in pairs of tones. The results suggest a division of labor between the two hemispheres such that the FM direction of each individual tone is mainly processed in the right auditory cortex whereas the sequential comparison of this feature between tones in a pair is probably performed in the left auditory cortex.

  17. Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.

    Science.gov (United States)

    Smirni, Daniela; Turriziani, Patrizia; Mangano, Giuseppa Renata; Bracco, Martina; Oliveri, Massimiliano; Cipolotti, Lisa

    2017-07-28

    A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS) over left and right lateral frontal cortex (BA 47) on two phonemic fluency tasks (FAS or FPL). 44 right-handed HCs were administered rTMS or sham over the left or right lateral frontal cortex in two separate testing sessions, with a 24h interval, followed by the two phonemic fluency tasks. To account for possible practice effects, an additional 22 HCs were tested on only the phonemic fluency task across two sessions with no stimulation. We found that rTMS-inhibition over the left lateral frontal cortex significantly worsened phonemic fluency performance when compared to sham. In contrast, rTMS-inhibition over the right lateral frontal cortex significantly improved phonemic fluency performance when compared to sham. These results were not accounted for practice effects. We speculated that rTMS over the right lateral frontal cortex may induce plastic neural changes to the left lateral frontal cortex by suppressing interhemispheric inhibitory interactions. This resulted in an increased excitability (disinhibition) of the contralateral unstimulated left lateral frontal cortex, consequently enhancing phonemic fluency performance. Conversely, application of rTMS over the left lateral frontal cortex may induce a temporary, virtual lesion, with effects similar to those reported in left frontal

  18. Left Dorsal Premotor Cortex and Supramarginal Gyrus Complement Each Other during Rapid Action Reprogramming

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Bestmann, Sven; Ward, Nick S

    2012-01-01

    The ability to discard a prepared action plan in favor of an alternative action is critical when facing sudden environmental changes. We tested whether the functional contribution of left supramarginal gyrus (SMG) during action reprogramming depends on the functional integrity of left dorsal...... premotor cortex (PMd). Adopting a dual-site repetitive transcranial magnetic stimulation (rTMS) strategy, we first transiently disrupted PMd with "off-line" 1 Hz rTMS and then applied focal "on-line" rTMS to SMG while human subjects performed a spatially precued reaction time (RT) task. Effective on-line r......TMS of SMG but not sham rTMS of SMG increased errors when subjects had to reprogram their action in response to an invalid precue regardless of the type of preceding off-line rTMS. This suggests that left SMG primarily contributes to the on-line updating of actions by suppressing invalidly prepared responses...

  19. Contralateral white noise selectively changes left human auditory cortex activity in a lexical decision task.

    Science.gov (United States)

    Behne, Nicole; Wendt, Beate; Scheich, Henning; Brechmann, André

    2006-04-01

    In a previous study, we hypothesized that the approach of presenting information-bearing stimuli to one ear and noise to the other ear may be a general strategy to determine hemispheric specialization in auditory cortex (AC). In that study, we confirmed the dominant role of the right AC in directional categorization of frequency modulations by showing that fMRI activation of right but not left AC was sharply emphasized when masking noise was presented to the contralateral ear. Here, we tested this hypothesis using a lexical decision task supposed to be mainly processed in the left hemisphere. Subjects had to distinguish between pseudowords and natural words presented monaurally to the left or right ear either with or without white noise to the other ear. According to our hypothesis, we expected a strong effect of contralateral noise on fMRI activity in left AC. For the control conditions without noise, we found that activation in both auditory cortices was stronger on contralateral than on ipsilateral word stimulation consistent with a more influential contralateral than ipsilateral auditory pathway. Additional presentation of contralateral noise did not significantly change activation in right AC, whereas it led to a significant increase of activation in left AC compared with the condition without noise. This is consistent with a left hemispheric specialization for lexical decisions. Thus our results support the hypothesis that activation by ipsilateral information-bearing stimuli is upregulated mainly in the hemisphere specialized for a given task when noise is presented to the more influential contralateral ear.

  20. Accurate external localization of the left frontal cortex in dogs by using pointer based frameless neuronavigation

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    Robrecht Dockx

    2017-07-01

    Full Text Available Background In humans, non-stereotactic frameless neuronavigation systems are used as a topographical tool for non-invasive brain stimulation methods such as Transcranial Magnetic Stimulation (TMS. TMS studies in dogs may provide treatment modalities for several neuropsychological disorders in dogs. Nevertheless, an accurate non-invasive localization of a stimulation target has not yet been performed in this species. Hypothesis This study was primarily put forward to externally locate the left frontal cortex in 18 healthy dogs by means of a human non-stereotactic neuronavigation system. Secondly, the accuracy of the external localization was assessed. Animals A total of 18 healthy dogs, drawn at random from the research colony present at the faculty of Veterinary Medicine (Ghent University, were used. Methods Two sets of coordinates (X, Y, Z and X″, Y″, Z″ were compared on each dog their tomographical dataset. Results The non-stereotactic neuronavigation system was able to externally locate the frontal cortex in dogs with accuracy comparable with human studies. Conclusion and clinical importance This result indicates that a non-stereotactic neuronavigation system can accurately externally locate the left frontal cortex and paves the way to use guided non-invasive brain stimulation methods as an alternative treatment procedure for neurological and behavioral disorders in dogs. This technique could, in analogy with human guided non-invasive brain stimulation, provide a better treatment outcome for dogs suffering from anxiety disorders when compared to its non-guided alternative.

  1. Left auditory cortex gamma synchronization and auditory hallucination symptoms in schizophrenia

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    Shenton Martha E

    2009-07-01

    Full Text Available Abstract Background Oscillatory electroencephalogram (EEG abnormalities may reflect neural circuit dysfunction in neuropsychiatric disorders. Previously we have found positive correlations between the phase synchronization of beta and gamma oscillations and hallucination symptoms in schizophrenia patients. These findings suggest that the propensity for hallucinations is associated with an increased tendency for neural circuits in sensory cortex to enter states of oscillatory synchrony. Here we tested this hypothesis by examining whether the 40 Hz auditory steady-state response (ASSR generated in the left primary auditory cortex is positively correlated with auditory hallucination symptoms in schizophrenia. We also examined whether the 40 Hz ASSR deficit in schizophrenia was associated with cross-frequency interactions. Sixteen healthy control subjects (HC and 18 chronic schizophrenia patients (SZ listened to 40 Hz binaural click trains. The EEG was recorded from 60 electrodes and average-referenced offline. A 5-dipole model was fit from the HC grand average ASSR, with 2 pairs of superior temporal dipoles and a deep midline dipole. Time-frequency decomposition was performed on the scalp EEG and source data. Results Phase locking factor (PLF and evoked power were reduced in SZ at fronto-central electrodes, replicating prior findings. PLF was reduced in SZ for non-homologous right and left hemisphere sources. Left hemisphere source PLF in SZ was positively correlated with auditory hallucination symptoms, and was modulated by delta phase. Furthermore, the correlations between source evoked power and PLF found in HC was reduced in SZ for the LH sources. Conclusion These findings suggest that differential neural circuit abnormalities may be present in the left and right auditory cortices in schizophrenia. In addition, they provide further support for the hypothesis that hallucinations are related to cortical hyperexcitability, which is manifested by

  2. Functional specialization of the left ventral parietal cortex in working memory

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    Jennifer Lou Langel

    2014-06-01

    Full Text Available The function of the ventral parietal cortex (VPC is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

  3. Brain structural network topological alterations of the left prefrontal and limbic cortex in psychogenic erectile dysfunction.

    Science.gov (United States)

    Chen, Jianhuai; Chen, Yun; Gao, Qingqiang; Chen, Guotao; Dai, Yutian; Yao, Zhijian; Lu, Qing

    2018-05-01

    Despite increasing understanding of the cerebral functional changes and structural abnormalities in erectile dysfunction, alterations in the topological organization of brain networks underlying psychogenic erectile dysfunction remain unclear. Here, based on the diffusion tensor image data of 25 patients and 26 healthy controls, we investigated the topological organization of brain structural networks and its correlations with the clinical variables using the graph theoretical analysis. Patients displayed a preserved overall small-world organization and exhibited a less connectivity strength in the left inferior frontal gyrus, amygdale and the right inferior temporal gyrus. Moreover, an abnormal hub pattern was observed in patients, which might disturb the information interactions of the remaining brain network. Additionally, the clustering coefficient of the left hippocampus was positively correlated with the duration of patients and the normalized betweenness centrality of the right anterior cingulate gyrus and the left calcarine fissure were negatively correlated with the sum scores of the 17-item Hamilton Depression Rating Scale. These findings suggested that the damaged white matter and the abnormal hub distribution of the left prefrontal and limbic cortex might contribute to the pathogenesis of psychogenic erectile dysfunction and provided new insights into the understanding of the pathophysiological mechanisms of psychogenic erectile dysfunction.

  4. Subliminal semantic priming changes the dynamic causal influence between the left frontal and temporal cortex.

    Science.gov (United States)

    Matsumoto, Atsushi; Kakigi, Ryusuke

    2014-01-01

    Recent neuroimaging experiments have revealed that subliminal priming of a target stimulus leads to the reduction of neural activity in specific regions concerned with processing the target. Such findings lead to questions about the degree to which the subliminal priming effect is based only on decreased activity in specific local brain regions, as opposed to the influence of neural mechanisms that regulate communication between brain regions. To address this question, this study recorded EEG during performance of a subliminal semantic priming task. We adopted an information-based approach that used independent component analysis and multivariate autoregressive modeling. Results indicated that subliminal semantic priming caused significant modulation of alpha band activity in the left inferior frontal cortex and modulation of gamma band activity in the left inferior temporal regions. The multivariate autoregressive approach confirmed significant increases in information flow from the inferior frontal cortex to inferior temporal regions in the early time window that was induced by subliminal priming. In the later time window, significant enhancement of bidirectional causal flow between these two regions underlying subliminal priming was observed. Results suggest that unconscious processing of words influences not only local activity of individual brain regions but also the dynamics of neural communication between those regions.

  5. Enhancement Of Motor Recovery Through Left Dorsolateral Prefrontal Cortex Stimulation After Acute Ischemic Stroke

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    Shahram Oveisgharan

    2017-02-01

    Full Text Available Background: Two previous studies, which investigated transcranial direct current stimulation (tDCS use in motor recovery after acute ischemic stroke, did not show tDCS to be effective in this regard. We speculated that additional left dorsolateral prefrontal cortex ‎(DLPFC ‎stimulation may enhance post stroke motor recovery.  ‎ Methods: In the present randomized clinical trial, 20 acute ischemic stroke patients were recruited. Patients received real motor cortex (M1 stimulation in both arms of the trial. The two arms differed in terms of real vs. sham stimulation over the left DLPFC‎. Motor component of the Fugl-Meyer upper extremity assessment (FM and Action Research Arm Test (ARAT scores were used to assess primary outcomes, and non-linear mixed effects models were used for data analyses. Results: Primary outcome measures improved more and faster among the real stimulation group. During the first days of stimulations, sham group’s FM scores increased 1.2 scores per day, while real group’s scores increased 1.7 scores per day (P = 0.003. In the following days, FM improvement decelerated in both groups. Based on the derived models, a hypothetical stroke patient with baseline FM score of 15 improves to 32 in the sham stimulation group and to 41 in the real stimulation group within the first month after stroke. Models with ARAT scores yielded nearly similar results. Conclusion: The current study results showed that left DLPFC‎ stimulation in conjunction with M1 stimulation resulted in better motor recovery than M1 stimulation alone.

  6. Enhancing motor network activity using real-time functional MRI neurofeedback of left premotor cortex

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    Theo Ferreira Marins

    2015-12-01

    Full Text Available Neurofeedback by functional Magnetic Resonance Imaging (fMRI is a technique of potential therapeutic relevance that allows individuals to be aware of their own neurophysiological responses and to voluntarily modulate the activity of specific brain regions, such as the premotor cortex (PMC, important for motor recovery after brain injury. We investigated (i whether healthy human volunteers are able to up-regulate the activity of the left PMC during a right hand finger tapping motor imagery (MI task while receiving continuous fMRI-neurofeedback, and (ii whether successful modulation of brain activity influenced non-targeted motor control regions. During the MI task, participants of the neurofeedback group (NFB received ongoing visual feedback representing the level of fMRI responses within their left PMC. Control (CTL group participants were shown similar visual stimuli, but these were non-contingent on brain activity. Both groups showed equivalent levels of behavioral ratings on arousal and motor imagery, before and during the fMRI protocol. In the NFB, but not in CLT group, brain activation during the last run compared to the first run revealed increased activation in the left PMC. In addition, the NFB group showed increased activation in motor control regions extending beyond the left PMC target area, including the supplementary motor area, basal ganglia and cerebellum. Moreover, in the last run, the NFB group showed stronger activation in the left PMC/inferior frontal gyrus when compared to the CTL group. Our results indicate that modulation of PMC and associated motor control areas can be achieved during a single neurofeedback-fMRI session. These results contribute to a better understanding of the underlying mechanisms of MI-based neurofeedback training, with direct implications for rehabilitation strategies in severe brain disorders, such as stroke.

  7. Lesions to the left lateral prefrontal cortex impair decision threshold adjustment for lexical selection.

    Science.gov (United States)

    Anders, Royce; Riès, Stéphanie; Van Maanen, Leendert; Alario, F-Xavier

    Patients with lesions in the left prefrontal cortex (PFC) have been shown to be impaired in lexical selection, especially when interference between semantically related alternatives is increased. To more deeply investigate which computational mechanisms may be impaired following left PFC damage due to stroke, a psychometric modelling approach is employed in which we assess the cognitive parameters of the patients from an evidence accumulation (sequential information sampling) modelling of their response data. We also compare the results to healthy speakers. Analysis of the cognitive parameters indicates an impairment of the PFC patients to appropriately adjust their decision threshold, in order to handle the increased item difficulty that is introduced by semantic interference. Also, the modelling contributes to other topics in psycholinguistic theory, in which specific effects are observed on the cognitive parameters according to item familiarization, and the opposing effects of priming (lower threshold) and semantic interference (lower drift) which are found to depend on repetition. These results are developed for the blocked-cyclic picture naming paradigm, in which pictures are presented within semantically homogeneous (HOM) or heterogeneous (HET) blocks, and are repeated several times per block. Overall, the results are in agreement with a role of the left PFC in adjusting the decision threshold for lexical selection in language production.

  8. Transcranial direct current stimulation of the left dorsolateral prefrontal cortex shifts preference of moral judgments.

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    Maria Kuehne

    Full Text Available Attitude to morality, reflecting cultural norms and values, is considered unique to human social behavior. Resulting moral behavior in a social environment is controlled by a widespread neural network including the dorsolateral prefrontal cortex (DLPFC, which plays an important role in decision making. In the present study we investigate the influence of neurophysiological modulation of DLPFC reactivity by means of transcranial direct current stimulation (tDCS on moral reasoning. For that purpose we administered anodal, cathodal, and sham stimulation of the left DLPFC while subjects judged the appropriateness of hard moral personal dilemmas. In contrast to sham and cathodal stimulation, anodal stimulation induced a shift in judgment of personal moral dilemmas towards more non-utilitarian actions. Our results demonstrate that alterations of left DLPFC activity can change moral judgments and, in consequence, provide a causal link between left DLPFC activity and moral reasoning. Most important, the observed shift towards non-utilitarian actions suggests that moral decision making is not a permanent individual trait but can be manipulated; consequently individuals with boundless, uncontrollable, and maladaptive moral behavior, such as found in psychopathy, might benefit from neuromodulation-based approaches.

  9. Increased BOLD Signals Elicited by High Gamma Auditory Stimulation of the Left Auditory Cortex in Acute State Schizophrenia

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    Hironori Kuga, M.D.

    2016-10-01

    We acquired BOLD responses elicited by click trains of 20, 30, 40 and 80-Hz frequencies from 15 patients with acute episode schizophrenia (AESZ, 14 symptom-severity-matched patients with non-acute episode schizophrenia (NASZ, and 24 healthy controls (HC, assessed via a standard general linear-model-based analysis. The AESZ group showed significantly increased ASSR-BOLD signals to 80-Hz stimuli in the left auditory cortex compared with the HC and NASZ groups. In addition, enhanced 80-Hz ASSR-BOLD signals were associated with more severe auditory hallucination experiences in AESZ participants. The present results indicate that neural over activation occurs during 80-Hz auditory stimulation of the left auditory cortex in individuals with acute state schizophrenia. Given the possible association between abnormal gamma activity and increased glutamate levels, our data may reflect glutamate toxicity in the auditory cortex in the acute state of schizophrenia, which might lead to progressive changes in the left transverse temporal gyrus.

  10. Accessing orthographic representations from speech: the role of left ventral occipitotemporal cortex in spelling.

    Science.gov (United States)

    Ludersdorfer, Philipp; Kronbichler, Martin; Wimmer, Heinz

    2015-04-01

    The present fMRI study used a spelling task to investigate the hypothesis that the left ventral occipitotemporal cortex (vOT) hosts neuronal representations of whole written words. Such an orthographic word lexicon is posited by cognitive dual-route theories of reading and spelling. In the scanner, participants performed a spelling task in which they had to indicate if a visually presented letter is present in the written form of an auditorily presented word. The main experimental manipulation distinguished between an orthographic word spelling condition in which correct spelling decisions had to be based on orthographic whole-word representations, a word spelling condition in which reliance on orthographic whole-word representations was optional and a phonological pseudoword spelling condition in which no reliance on such representations was possible. To evaluate spelling-specific activations the spelling conditions were contrasted with control conditions that also presented auditory words and pseudowords, but participants had to indicate if a visually presented letter corresponded to the gender of the speaker. We identified a left vOT cluster activated for the critical orthographic word spelling condition relative to both the control condition and the phonological pseudoword spelling condition. Our results suggest that activation of left vOT during spelling can be attributed to the retrieval of orthographic whole-word representations and, thus, support the position that the left vOT potentially represents the neuronal equivalent of the cognitive orthographic word lexicon. © 2014 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  11. tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

    Science.gov (United States)

    Vanderhasselt, Marie-Anne; De Raedt, Rudi; Brunoni, Andre R; Campanhã, Camila; Baeken, Chris; Remue, Jonathan; Boggio, Paulo S

    2013-01-01

    Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP) as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation), we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right) prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

  12. tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

    Directory of Open Access Journals (Sweden)

    Marie-Anne Vanderhasselt

    Full Text Available Transcranial Direct Current Stimulation (tDCS is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation, we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

  13. Categorization is modulated by transcranial direct current stimulation over left prefrontal cortex.

    Science.gov (United States)

    Lupyan, Gary; Mirman, Daniel; Hamilton, Roy; Thompson-Schill, Sharon L

    2012-07-01

    Humans have an unparalleled ability to represent objects as members of multiple categories. A given object, such as a pillow may be-depending on current task demands-represented as an instance of something that is soft, as something that contains feathers, as something that is found in bedrooms, or something that is larger than a toaster. This type of processing requires the individual to dynamically highlight task-relevant properties and abstract over or suppress object properties that, although salient, are not relevant to the task at hand. Neuroimaging and neuropsychological evidence suggests that this ability may depend on cognitive control processes associated with the left inferior prefrontal gyrus. Here, we show that stimulating the left inferior frontal cortex using transcranial direct current stimulation alters performance of healthy subjects on a simple categorization task. Our task required subjects to select pictures matching a description, e.g., "click on all the round things." Cathodal stimulation led to poorer performance on classification trials requiring attention to specific dimensions such as color or shape as opposed to trials that required selecting items belonging to a more thematic category such as objects that hold water. A polarity reversal (anodal stimulation) lowered the threshold for selecting items that were more weakly associated with the target category. These results illustrate the role of frontally-mediated control processes in categorization and suggest potential interactions between categorization, cognitive control, and language. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Categorization is modulated by transcranical direct current stimulation over left prefrontal cortex

    Science.gov (United States)

    Lupyan, Gary; Mirman, Daniel; Hamilton, Roy; Thompson-Schill, Sharon L.

    2013-01-01

    Humans have an unparalleled ability to represent objects as members of multiple categories. A given object, such as a pillow may be—depending on current task demands—represented as an instance of something that is soft, as something that contains feathers, as something that is found in bedrooms, or something that is larger than a toaster. This type of processing requires the individual to dynamically highlight task-relevant properties and abstract over or suppress object properties that, although salient, are not relevant to the task at hand. Neuroimaging and neuropsychological evidence suggests that this ability may depend on cognitive control processes associated with the left inferior prefrontal gyrus. Here, we show that stimulating the left inferior frontal cortex using transcranial direct current stimulation alters performance of healthy subjects on a simple categorization task. Our task required subjects to select pictures matching a description, e.g., “click on all the round things.“ Cathodal stimulation led to poorer performance on classification trials requiring attention to specific dimensions such as color or shape as opposed to trials that required selecting items belonging to a more thematic category such as objects that hold water. A polarity reversal (anodal stimulation) lowered the threshold for selecting items that were more weakly associated with the target category. These results illustrate the role of frontally-mediated control processes in categorization and suggest potential interactions between categorization, cognitive control, and language. PMID:22578885

  15. Right vs. left sensorimotor cortex suction-ablation in the rat: no difference in beam-walking recovery.

    Science.gov (United States)

    Goldstein, L B

    1995-03-13

    The ability of rats to traverse a narrow elevated beam has been used to quantitate recovery of hindlimb motor function after unilateral injury to the sensorimotor cortex. We tested the hypothesis that the rate of spontaneous beam-walking recovery varies with the side of the cortex lesion. Groups of rats that were trained at the beam-walking task underwent suction-ablation of either the right or left hindlimb sensorimotor cortex. There was no difference in hindlimb motor function between the groups on the first post-operative beam-waking trial carried out the day after cortex ablation and no difference between the groups in overall recovery rates over the next two weeks. Subsequent analyses of lesion surface parameters showed no differences in lesion size or extent. Regardless of the side of the lesion, there were also no differences between the right and left hemispheres in norepinephrine content of the lesioned or contralateral cortex. We conclude that the side of sensorimotor cortex ablation injury does not differentially affect the rate of spontaneous motor recovery as measured with the beam-walking task.

  16. Low-frequency transcranial magnetic stimulation over left dorsal premotor cortex improves the dynamic control of visuospatially cued actions

    DEFF Research Database (Denmark)

    Ward, Nick S; Bestmann, Sven; Hartwigsen, Gesa

    2010-01-01

    Left rostral dorsal premotor cortex (rPMd) and supramarginal gyrus (SMG) have been implicated in the dynamic control of actions. In 12 right-handed healthy individuals, we applied 30 min of low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) over left rPMd to investigate...... the involvement of left rPMd and SMG in the rapid adjustment of actions guided by visuospatial cues. After rTMS, subjects underwent functional magnetic resonance imaging while making spatially congruent button presses with the right or left index finger in response to a left- or right-sided target. Subjects were...... that left rPMd and SMG-AIP contribute toward dynamic control of actions and demonstrate that low-frequency rTMS can enhance functional coupling between task-relevant brain regions and improve some aspects of motor performance....

  17. Transcranial direct current stimulation over left inferior frontal cortex improves speech fluency in adults who stutter.

    Science.gov (United States)

    Chesters, Jennifer; Möttönen, Riikka; Watkins, Kate E

    2018-04-01

    See Crinion (doi:10.1093/brain/awy075) for a scientific commentary on this article.Stuttering is a neurodevelopmental condition affecting 5% of children, and persisting in 1% of adults. Promoting lasting fluency improvement in adults who stutter is a particular challenge. Novel interventions to improve outcomes are of value, therefore. Previous work in patients with acquired motor and language disorders reported enhanced benefits of behavioural therapies when paired with transcranial direct current stimulation. Here, we report the results of the first trial investigating whether transcranial direct current stimulation can improve speech fluency in adults who stutter. We predicted that applying anodal stimulation to the left inferior frontal cortex during speech production with temporary fluency inducers would result in longer-lasting fluency improvements. Thirty male adults who stutter completed a randomized, double-blind, controlled trial of anodal transcranial direct current stimulation over left inferior frontal cortex. Fifteen participants received 20 min of 1-mA stimulation on five consecutive days while speech fluency was temporarily induced using choral and metronome-timed speech. The other 15 participants received the same speech fluency intervention with sham stimulation. Speech fluency during reading and conversation was assessed at baseline, before and after the stimulation on each day of the 5-day intervention, and at 1 and 6 weeks after the end of the intervention. Anodal stimulation combined with speech fluency training significantly reduced the percentage of disfluent speech measured 1 week after the intervention compared with fluency intervention alone. At 6 weeks after the intervention, this improvement was maintained during reading but not during conversation. Outcome scores at both post-intervention time points on a clinical assessment tool (the Stuttering Severity Instrument, version 4) also showed significant improvement in the group receiving

  18. Examining Brain-Cognition Effects of Ginkgo Biloba Extract: Brain Activation in the Left Temporal and Left Prefrontal Cortex in an Object Working Memory Task

    Directory of Open Access Journals (Sweden)

    R. B. Silberstein

    2011-01-01

    Full Text Available Ginkgo Biloba extract (GBE is increasingly used to alleviate symptoms of age related cognitive impairment, with preclinical evidence pointing to a pro-cholinergic effect. While a number of behavioral studies have reported improvements to working memory (WM associated with GBE, electrophysiological studies of GBE have typically been limited to recordings during a resting state. The current study investigated the chronic effects of GBE on steady state visually evoked potential (SSVEP topography in nineteen healthy middle-aged (50-61 year old male participants whilst completing an object WM task. A randomized double-blind crossover design was employed in which participants were allocated to receive 14 days GBE and 14 days placebo in random order. For both groups, SSVEP was recorded from 64 scalp electrode sites during the completion of an object WM task both pre- and 14 days post-treatment. GBE was found to improve behavioural performance on the WM task. GBE was also found to increase the SSVEP amplitude at occipital and frontal sites and increase SSVEP latency at left temporal and left frontal sites during the hold component of the WM task. These SSVEP changes associated with GBE may represent more efficient processing during WM task completion.

  19. Left insular cortex and left SFG underlie prismatic adaptation effects on time perception: evidence from fMRI.

    Science.gov (United States)

    Magnani, Barbara; Frassinetti, Francesca; Ditye, Thomas; Oliveri, Massimiliano; Costantini, Marcello; Walsh, Vincent

    2014-05-15

    Prismatic adaptation (PA) has been shown to affect left-to-right spatial representations of temporal durations. A leftward aftereffect usually distorts time representation toward an underestimation, while rightward aftereffect usually results in an overestimation of temporal durations. Here, we used functional magnetic resonance imaging (fMRI) to study the neural mechanisms that underlie PA effects on time perception. Additionally, we investigated whether the effect of PA on time is transient or stable and, in the case of stability, which cortical areas are responsible of its maintenance. Functional brain images were acquired while participants (n=17) performed a time reproduction task and a control-task before, immediately after and 30 min after PA inducing a leftward aftereffect, administered outside the scanner. The leftward aftereffect induced an underestimation of time intervals that lasted for at least 30 min. The left anterior insula and the left superior frontal gyrus showed increased functional activation immediately after versus before PA in the time versus the control-task, suggesting these brain areas to be involved in the executive spatial manipulation of the representation of time. The left middle frontal gyrus showed an increase of activation after 30 min with respect to before PA. This suggests that this brain region may play a key role in the maintenance of the PA effect over time. Copyright © 2014. Published by Elsevier Inc.

  20. Region-specific aging of the human brain as evidenced by neurochemical profiles measured noninvasively in the posterior cingulate cortex and the occipital lobe using 1H magnetic resonance spectroscopy at 7 T.

    Science.gov (United States)

    Marjańska, Małgorzata; McCarten, J Riley; Hodges, James; Hemmy, Laura S; Grant, Andrea; Deelchand, Dinesh K; Terpstra, Melissa

    2017-06-23

    The concentrations of fourteen neurochemicals associated with metabolism, neurotransmission, antioxidant capacity, and cellular structure were measured noninvasively from two distinct brain regions using 1 H magnetic resonance spectroscopy. Seventeen young adults (age 19-22years) and sixteen cognitively normal older adults (age 70-88years) were scanned. To increase sensitivity and specificity, 1 H magnetic resonance spectra were obtained at the ultra-high field of 7T and at ultra-short echo time. The concentrations of neurochemicals were determined using water as an internal reference and accounting for gray matter, white matter, and cerebrospinal fluid content of the volume of interest. In the posterior cingulate cortex (PCC), the concentrations of neurochemicals associated with energy (i.e., creatine plus phosphocreatine), membrane turnover (i.e., choline containing compounds), and gliosis (i.e., myo-inositol) were higher in the older adults while the concentrations of N-acetylaspartylglutamate (NAAG) and phosphorylethanolamine (PE) were lower. In the occipital cortex (OCC), the concentration of N-acetylaspartate (NAA), a marker of neuronal viability, concentrations of the neurotransmitters Glu and NAAG, antioxidant ascorbate (Asc), and PE were lower in the older adults while the concentration of choline containing compounds was higher. Altogether, these findings shed light on how the human brain ages differently depending on region. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Modulation of the Left Prefrontal Cortex with High Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Gait in Multiple Sclerosis

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    Amer M. Burhan

    2015-01-01

    Full Text Available Multiple Sclerosis (MS is a chronic central nervous system (CNS demyelinating disease. Gait abnormalities are common and disabling in patients with MS with limited treatment options available. Emerging evidence suggests a role of prefrontal attention networks in modulating gait. High-frequency repetitive transcranial magnetic stimulation (rTMS is known to enhance cortical excitability in stimulated cortex and its correlates. We investigated the effect of high-frequency left prefrontal rTMS on gait parameters in a 51-year-old Caucasian male with chronic relapsing/remitting MS with residual disabling attention and gait symptoms. Patient received 6 Hz, rTMS at 90% motor threshold using figure of eight coil centered on F3 location (using 10-20 electroencephalography (EEG lead localization system. GAITRite gait analysis system was used to collect objective gait measures before and after one session and in another occasion three consecutive daily sessions of rTMS. Two-tailed within subject repeated measure t-test showed significant enhancement in ambulation time, gait velocity, and cadence after three consecutive daily sessions of rTMS. Modulating left prefrontal cortex excitability using rTMS resulted in significant change in gait parameters after three sessions. To our knowledge, this is the first report that demonstrates the effect of rTMS applied to the prefrontal cortex on gait in MS patients.

  2. Improvement of visual field defects after focal resection for occipital lobe epilepsy: case report.

    Science.gov (United States)

    Yamamoto, Takahiro; Hamasaki, Tadashi; Nakamura, Hideo; Yamada, Kazumichi

    2018-03-01

    Improvement of visual field defects after surgical treatment for occipital lobe epilepsy is rare. Here, the authors report on a 24-year-old man with a 15-year history of refractory epilepsy that developed after he had undergone an occipital craniotomy to remove a cerebellar astrocytoma at the age of 4. His seizures started with an elementary visual aura, followed by secondary generalized tonic-clonic convulsion. Perimetry revealed left-sided incomplete hemianopia, and MRI showed an old contusion in the right occipital lobe. After evaluation with ictal video-electroencephalography, electrocorticography, and mapping of the visual cortex with subdural electrodes, the patient underwent resection of the scarred tissue, including the epileptic focus at the occipital lobe. After surgery, he became seizure free and his visual field defect improved gradually. In addition, postoperative 123 I-iomazenil (IMZ) SPECT showed partly normalized IMZ uptake in the visual cortex. This case is a practical example suggesting that neurological deficits attributable to the functional deficit zone can be remedied by successful focal resection.

  3. Occipital neuralgia: anatomic considerations.

    Science.gov (United States)

    Cesmebasi, Alper; Muhleman, Mitchel A; Hulsberg, Paul; Gielecki, Jerzy; Matusz, Petru; Tubbs, R Shane; Loukas, Marios

    2015-01-01

    Occipital neuralgia is a debilitating disorder first described in 1821 as recurrent headaches localized in the occipital region. Other symptoms that have been associated with this condition include paroxysmal burning and aching pain in the distribution of the greater, lesser, or third occipital nerves. Several etiologies have been identified in the cause of occipital neuralgia and include, but are not limited to, trauma, fibrositis, myositis, fracture of the atlas, and compression of the C-2 nerve root, C1-2 arthrosis syndrome, atlantoaxial lateral mass osteoarthritis, hypertrophic cervical pachymeningitis, cervical cord tumor, Chiari malformation, and neurosyphilis. The management of occipital neuralgia can include conservative approaches and/or surgical interventions. Occipital neuralgia is a multifactorial problem where multiple anatomic areas/structures may be involved with this pathology. A review of these etiologies may provide guidance in better understanding occipital neuralgia. © 2014 Wiley Periodicals, Inc.

  4. Mirror focus in a patient with intractable occipital lobe epilepsy.

    Science.gov (United States)

    Kim, Jiyoung; Shin, Hae Kyung; Hwang, Kyoung Jin; Choi, Su Jung; Joo, Eun Yeon; Hong, Seung Bong; Hong, Seung Chul; Seo, Dae-Won

    2014-06-01

    Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy. We have observed occipital lobe epilepsy with mirror focus. Before epilepsy surgery, the subject's seizure onset zone was observed in the left occipital area by ictal studies. Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then. The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area. This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.

  5. Hyperlexia and ambient echolalia in a case of cerebral infarction of the left anterior cingulate cortex and corpus callosum.

    Science.gov (United States)

    Suzuki, Tadashi; Itoh, Shouichi; Hayashi, Mototaka; Kouno, Masako; Takeda, Katsuhiko

    2009-10-01

    We report the case of a 69-year-old woman with cerebral infarction in the left anterior cingulate cortex and corpus callosum. She showed hyperlexia, which was a distinctive reading phenomenon, as well as ambient echolalia. Clinical features also included complex disorders such as visual groping, compulsive manipulation of tools, and callosal disconnection syndrome. She read words written on the cover of a book and repeated words emanating from unrelated conversations around her or from hospital announcements. The combination of these two features due to a focal lesion has never been reported previously. The supplementary motor area may control the execution of established subroutines according to external and internal inputs. Hyperlexia as well as the compulsive manipulation of tools could be interpreted as faulty inhibition of preexisting essentially intact motor subroutines by damage to the anterior cingulate cortex reciprocally interconnected with the supplementary motor area.

  6. Effects of Unilateral Transcranial Direct Current Stimulation of Left Prefrontal Cortex on Processing and Memory of Emotional Visual Stimuli.

    Directory of Open Access Journals (Sweden)

    Stefania Balzarotti

    Full Text Available The dorsolateral prefrontal cortex (DLPFC is generally thought to be involved in affect and emotional processing; however, the specific contribution of each hemisphere continues to be debated. In the present study, we employed unilateral tDCS to test the unique contribution of left DLPFC in the encoding and retrieval of emotional stimuli in healthy subjects. Forty-two right handed undergraduate students received either anodal, cathodal or sham stimulation of left DLPFC while viewing neutral, pleasant, and unpleasant pictures. After completing a filler task, participants were asked to remember as many pictures as possible. Results showed that participants were able to remember a larger amount of emotional (both pleasant and unpleasant pictures than of neutral ones, regardless of the type of tDCS condition. Participants who received anodal stimulation recalled a significantly higher number of pleasant images than participants in the sham and cathodal conditions, while no differences emerged in the recall of neutral and unpleasant pictures. We conclude that our results provide some support to the role of left prefrontal cortex in the encoding and retrieval of pleasant stimuli.

  7. Effects of Unilateral Transcranial Direct Current Stimulation of Left Prefrontal Cortex on Processing and Memory of Emotional Visual Stimuli.

    Science.gov (United States)

    Balzarotti, Stefania; Colombo, Barbara

    2016-01-01

    The dorsolateral prefrontal cortex (DLPFC) is generally thought to be involved in affect and emotional processing; however, the specific contribution of each hemisphere continues to be debated. In the present study, we employed unilateral tDCS to test the unique contribution of left DLPFC in the encoding and retrieval of emotional stimuli in healthy subjects. Forty-two right handed undergraduate students received either anodal, cathodal or sham stimulation of left DLPFC while viewing neutral, pleasant, and unpleasant pictures. After completing a filler task, participants were asked to remember as many pictures as possible. Results showed that participants were able to remember a larger amount of emotional (both pleasant and unpleasant) pictures than of neutral ones, regardless of the type of tDCS condition. Participants who received anodal stimulation recalled a significantly higher number of pleasant images than participants in the sham and cathodal conditions, while no differences emerged in the recall of neutral and unpleasant pictures. We conclude that our results provide some support to the role of left prefrontal cortex in the encoding and retrieval of pleasant stimuli.

  8. Motor facilitation during observation of implied motion: Evidence for a role of the left dorsolateral prefrontal cortex.

    Science.gov (United States)

    Mineo, Ludovico; Fetterman, Alexander; Concerto, Carmen; Warren, Michael; Infortuna, Carmenrita; Freedberg, David; Chusid, Eileen; Aguglia, Eugenio; Battaglia, Fortunato

    2018-06-01

    The phenomenon of motor resonance (the increase in motor cortex excitability during observation of actions) has been previously described. Transcranial magnetic stimulation (TMS) studies have demonstrated a similar effect during perception of implied motion (IM). The left dorsolateral prefrontal cortex (DLPFC) seems to be activated during action observation. Furthermore, the role of this brain area in motor resonance to IM is yet to be investigated. Fourteen healthy volunteers were enrolled into the study. We used transcranial direct current stimulation (tDCS) to stimulate DLPFC aiming to investigate whether stimulation with different polarities would affect the amplitude of motor evoked potential collected during observation of images with and without IM. The results of our experiment indicated that Cathodal tDCS over the left DLPFC prevented motor resonance during observation of IM. On the contrary, anodal and sham tDCS did not significantly modulate motor resonance to IM. The current study expands the understanding of the neural circuits engaged during observation of IM. Our results are consistent with the hypothesis that action understanding requires the interaction of large networks and that the left DLPFC plays a crucial role in generating motor resonance to IM. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. The role of the left ventrolateral prefrontal cortex in online sentence processing

    Directory of Open Access Journals (Sweden)

    Nazbanou Nozari

    2014-04-01

    Full Text Available Introduction: Patients with damage to the left ventrolateral prefrontal cortex (VLPFC are often not impaired in understanding simple sentences. It is, however, possible that the damage may cause subclinical effects. If VLPFC has a role in biasing competition towards what is relevant to the task, we would expect patients with VLPFC damage to be slower in using the relevant information and discarding the irrelevant information when they process sentences online. Methods: Nine patients, five with lesions limited to VLPFC, and four with lesions sparing VLPFC participated. The groups were matched in age, education, WAB-AQ and total lesion volume. Two experiments explored processing of online cues during sentence comprehension by tracking eye fixations in a Visual World paradigm with four pictures. Participants only listened to the sentences and looked at the pictures. Experiment 1 investigated how quickly cues can be used for target identification using a simple “She will [verb] the [target].” sentence structure. The verbs in the restrictive condition were compatible with only one of the four pictures (e.g., “eat”; target “apple” + three inedible competitors. The verbs in the control conditions were matched to the restrictive verbs in length and frequency, but did not point to a unique target (e.g., “see”. If VLPFC is critical for quickly biasing competition towards the relevant target, the VLPFC patients should to be slower than the non-VLPFC patients in fixating the noun when the verb is restrictive. Experiment 2 probed how effectively irrelevant cues are suppressed. A similar Visual World paradigm was used, but all verbs were restrictive, and one of the distractors was also compatible with the verb (e.g., “banana”. The sentences contained an adjective that ruled out one of verb-compatible pictures (e.g., “red”. The critical manipulation involved a third picture (the adjective competitor which was compatible with the

  10. Reading skill related to left ventral occipitotemporal cortex during a phonological awareness task in 5–6-year old children

    Directory of Open Access Journals (Sweden)

    Jin Wang

    2018-04-01

    Full Text Available The left ventral occipitotemporal cortex (vOT is important in visual word recognition. Studies have shown that the left vOT is generally observed to be involved in spoken language processing in skilled readers, suggesting automatic access to corresponding orthographic information. However, little is known about where and how the left vOT is involved in the spoken language processing of young children with emerging reading ability. In order to answer this question, we examined the relation of reading ability in 5–6-year-old kindergarteners to the activation of vOT during an auditory phonological awareness task. Two experimental conditions: onset word pairs that shared the first phoneme and rhyme word pairs that shared the final biphone/triphone, were compared to allow a measurement of vOT’s activation to small (i.e., onsets and large grain sizes (i.e., rhymes. We found that higher reading ability was associated with better accuracy of the onset, but not the rhyme, condition. In addition, higher reading ability was only associated with greater sensitivity in the posterior left vOT for the contrast of the onset versus rhyme condition. These results suggest that acquisition of reading results in greater specialization of the posterior vOT to smaller rather than larger grain sizes in young children. Keywords: Left vOT, Grain size, Phonological awareness, Spoken language

  11. Transcranial Direct Current Stimulation over the Medial Prefrontal Cortex and Left Primary Motor Cortex (mPFC-lPMC) Affects Subjective Beauty but Not Ugliness

    Science.gov (United States)

    Nakamura, Koyo; Kawabata, Hideaki

    2015-01-01

    Neuroaesthetics has been searching for the neural bases of the subjective experience of beauty. It has been demonstrated that neural activities in the medial prefrontal cortex (mPFC) and the left primary motor cortex (lPMC) correlate with the subjective experience of beauty. Although beauty and ugliness seem to be semantically and conceptually opposite, it is still unknown whether these two evaluations represent extreme opposites in unitary or bivariate dimensions. In this study, we applied transcranial direct current stimulation (tDCS) to examine whether non-invasive brain stimulation modulates two types of esthetic evaluation; evaluating beauty and ugliness. Participants rated the subjective beauty and ugliness of abstract paintings before and after the application of tDCS. Application of cathodal tDCS over the mPFC with anode electrode over the lPMC, which induced temporal inhibition of neural excitability of the mPFC, led to a decrease in beauty ratings but not ugliness ratings. There were no changes in ratings of both beauty and ugliness when applying anodal tDCS or sham stimulation over the mPFC. Results from our experiment indicate that the mPFC and the lPMC have a causal role in generating the subjective experience of beauty, with beauty and ugliness evaluations constituting two distinct dimensions. PMID:26696865

  12. Hemifacial Pain and Hemisensory Disturbance Referred from Occipital Neuralgia Caused by Pathological Vascular Contact of the Greater Occipital Nerve.

    Science.gov (United States)

    Son, Byung-Chul; Choi, Jin-Gyu

    2017-01-01

    Here we report a unique case of chronic occipital neuralgia caused by pathological vascular contact of the left greater occipital nerve. After 12 months of left-sided, unremitting occipital neuralgia, a hypesthesia and facial pain developed in the left hemiface. The decompression of the left greater occipital nerve from pathological contacts with the occipital artery resulted in immediate relief for hemifacial sensory change and facial pain, as well as chronic occipital neuralgia. Although referral of pain from the stimulation of occipital and cervical structures innervated by upper cervical nerves to the frontal head of V1 trigeminal distribution has been reported, the development of hemifacial sensory change associated with referred trigeminal pain from chronic occipital neuralgia is extremely rare. Chronic continuous and strong afferent input of occipital neuralgia caused by pathological vascular contact with the greater occipital nerve seemed to be associated with sensitization and hypersensitivity of the second-order neurons in the trigeminocervical complex, a population of neurons in the C2 dorsal horn characterized by receiving convergent input from dural and cervical structures.

  13. Occipital bending in schizophrenia.

    Science.gov (United States)

    Maller, Jerome J; Anderson, Rodney J; Thomson, Richard H; Daskalakis, Zafiris J; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

    2017-01-01

    To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls. Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls. Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.1%]) than in control subjects (6/44 [13.6%]). Furthermore, those with schizophrenia had greater normalized gray matter volume but less white matter volume and had larger brain-to-cranial ratio. The results suggest that occipital bending is more prevalent among schizophrenia patients than healthy subjects and that schizophrenia patients have different gray matter-white matter proportions. Although the cause and clinical ramifications of occipital bending are unclear, the results infer that occipital bending may be a marker of psychiatric illness.

  14. Preliminary Evidence of "Other-Race Effect"-Like Behavior Induced by Cathodal-tDCS over the Right Occipital Cortex, in the Absence of Overall Effects on Face/Object Processing.

    Science.gov (United States)

    Costantino, Andrea I; Titoni, Matilde; Bossi, Francesco; Premoli, Isabella; Nitsche, Michael A; Rivolta, Davide

    2017-01-01

    Neuromodulation techniques such as tDCS have provided important insight into the neurophysiological mechanisms that mediate cognition. Albeit anodal tDCS (a-tDCS) often enhances cognitive skills, the role of cathodal tDCS (c-tDCS) in visual cognition is largely unexplored and inconclusive. Here, in a single-blind, sham-controlled study, we investigated the offline effects of 1.5 mA c-tDCS over the right occipital cortex of 86 participants on four tasks assessing perception and memory of both faces and objects. Results demonstrated that c-tDCS does not overall affect performance on the four tasks. However, post-hoc exploratory analysis on participants' race (Caucasian vs. non-Caucasians), showed a "face-specific" performance decrease (≈10%) in non-Caucasian participants only . This preliminary evidence suggests that c-tDCS can induce "other-race effect (ORE)-like" behavior in non-Caucasian participants that did not show any ORE before stimulation (and in case of sham stimulation). Our results add relevant information about the breadth of cognitive processes and visual stimuli that can be modulated by c-tDCS, about the design of effective neuromodulation protocols, and have important implications for the potential neurophysiological bases of ORE.

  15. Direct current induced short-term modulation of the left dorsolateral prefrontal cortex while learning auditory presented nouns

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    Meyer Martin

    2009-07-01

    Full Text Available Abstract Background Little is known about the contribution of transcranial direct current stimulation (tDCS to the exploration of memory functions. The aim of the present study was to examine the behavioural effects of right or left-hemisphere frontal direct current delivery while committing to memory auditory presented nouns on short-term learning and subsequent long-term retrieval. Methods Twenty subjects, divided into two groups, performed an episodic verbal memory task during anodal, cathodal and sham current application on the right or left dorsolateral prefrontal cortex (DLPFC. Results Our results imply that only cathodal tDCS elicits behavioural effects on verbal memory performance. In particular, left-sided application of cathodal tDCS impaired short-term verbal learning when compared to the baseline. We did not observe tDCS effects on long-term retrieval. Conclusion Our results imply that the left DLPFC is a crucial area involved in short-term verbal learning mechanisms. However, we found further support that direct current delivery with an intensity of 1.5 mA to the DLPFC during short-term learning does not disrupt longer lasting consolidation processes that are mainly known to be related to mesial temporal lobe areas. In the present study, we have shown that the tDCS technique has the potential to modulate short-term verbal learning mechanism.

  16. Near-Infrared Spectroscopy Reveals Abnormal Hemodynamics in the Left Dorsolateral Prefrontal Cortex of Menopausal Depression Patients

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    Xiang-Yun Ma

    2017-01-01

    Full Text Available Background/Objective. Menopausal depression (MD is characterized by depressive symptoms along with hormonal fluctuations. We investigate brain function alteration between major depressive disorder (MDD and MD. Methods. The difference in oxygenated hemoglobin (Oxy-Hb for the prefrontal cortex (PFC was compared retrospectively among 90 females presented with 30 MDD, 30 MD, and 30 healthy controls (HCs using verbal fluency task (VFT with near-infrared spectroscopy (NIRS. Results. We observed a significant difference in Oxy-Hb alteration in the left dorsolateral PFC (DLPFC using VFT with NIRS (channel 18, P=0.007 between the MD and MDD groups. A significant difference in Oxy-Hb levels was observed among the three groups in the bilateral DLPFC (channels 18, 27, 33, 39, 41, and 45; P<0.05. Compared to the HCs, the MD group presented lower Oxy-Hb activation in the right DLPFC (channel 41; P=0.048 and the left DLPFC (channels 18, 39, and 45; P<0.05, and the MDD group presented lower Oxy-Hb activation in the right DLPFC (channels 27, 33, and 41; P<0.05 and the left DLPFC (channels 39 and 45; P<0.05. Conclusion. Abnormal hemodynamics of the left DLPFC can differentiate MD from MDD by NIRS.

  17. Left Posterior Orbitofrontal Cortex Is Associated With Odor-Induced Autobiographical Memory: An fMRI Study

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    Keiko Watanabe

    2018-05-01

    Full Text Available Autobiographical odor memory (AM-odor accompanied by a sense of realism of a specific memory elicits strong emotions. AM-odor differs from memory triggered by other sensory modalities, possibly because olfaction involves a unique sensory process. Here, we examined the orbitofrontal cortex (OFC, using functional magnetic resonance imaging (fMRI to determine which OFC subregions are related to AM-odor. Both AM-odor and a control odor successively increased subjective ratings of comfortableness and pleasantness. Importantly, AM-odor also increased arousal levels and the vividness of memories, and was associated with a deep and slow breathing pattern. fMRI analysis indicated robust activation in the left posterior OFC (L-POFC. Connectivity between the POFC and whole brain regions was estimated using psychophysiological interaction analysis (PPI. We detected several trends in connectivity between L-POFC and bilateral precuneus, bilateral rostral dorsal anterior cingulate cortex (rdACC, and left parahippocampus, which will be useful for targeting our hypotheses for future investigations. The slow breathing observed in AM-odor was correlated with rdACC activation. Odor associated with emotionally significant autobiographical memories was accompanied by slow and deep breathing, possibly involving rdACC processing.

  18. Left Posterior Orbitofrontal Cortex Is Associated With Odor-Induced Autobiographical Memory: An fMRI Study.

    Science.gov (United States)

    Watanabe, Keiko; Masaoka, Yuri; Kawamura, Mitsuru; Yoshida, Masaki; Koiwa, Nobuyoshi; Yoshikawa, Akira; Kubota, Satomi; Ida, Masahiro; Ono, Kenjiro; Izumizaki, Masahiko

    2018-01-01

    Autobiographical odor memory (AM-odor) accompanied by a sense of realism of a specific memory elicits strong emotions. AM-odor differs from memory triggered by other sensory modalities, possibly because olfaction involves a unique sensory process. Here, we examined the orbitofrontal cortex (OFC), using functional magnetic resonance imaging (fMRI) to determine which OFC subregions are related to AM-odor. Both AM-odor and a control odor successively increased subjective ratings of comfortableness and pleasantness. Importantly, AM-odor also increased arousal levels and the vividness of memories, and was associated with a deep and slow breathing pattern. fMRI analysis indicated robust activation in the left posterior OFC (L-POFC). Connectivity between the POFC and whole brain regions was estimated using psychophysiological interaction analysis (PPI). We detected several trends in connectivity between L-POFC and bilateral precuneus, bilateral rostral dorsal anterior cingulate cortex (rdACC), and left parahippocampus, which will be useful for targeting our hypotheses for future investigations. The slow breathing observed in AM-odor was correlated with rdACC activation. Odor associated with emotionally significant autobiographical memories was accompanied by slow and deep breathing, possibly involving rdACC processing.

  19. Tempering Proactive Cognitive Control by Transcranial Direct Current Stimulation of the Right (but Not the Left Lateral Prefrontal Cortex

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    Carlos J. Gómez-Ariza

    2017-05-01

    Full Text Available Behavioral and neuroimaging data support the distinction of two different modes of cognitive control: proactive, which involves the active and sustained maintenance of task-relevant information to bias behavior in accordance with internal goals; and reactive, which entails the detection and resolution of interference at the time it occurs. Both control modes may be flexibly deployed depending on a variety of conditions (i.e., age, brain alterations, motivational factors, prior experience. Critically, and in line with specific predictions derived from the dual mechanisms of control account (Braver, 2012, findings from neuroimaging studies indicate that the same lateral prefrontal regions (i.e., left dorsolateral cortex and right inferior frontal junction may implement different control modes on the basis of temporal dynamics of activity, which would be modulated in response to external or internal conditions. In the present study, we aimed to explore whether transcraneal direct current stimulation over either the left dorsolateral prefrontal cortex or the right inferior frontal junction would differentially modulate performance on the AX-CPT, a well-validated task that provides sensitive and reliable behavioral indices of proactive/reactive control. The study comprised six conditions of real stimulation [3 (site: left dorsolateral, right dorsolateral and right inferior frontal junction × 2 (polarity: anodal and cathodal], and one sham condition. The reference electrode was always placed extracephalically. Performance on the AX-CPT was assessed through two blocks of trials. The first block took place while stimulation was being delivered, whereas the second block was administered after stimulation completion. The results indicate that both offline cathodal stimulation of the right dorsolateral prefrontal cortex and online anodal stimulation of the right inferior frontal junction led participants to be much less proactive, with such a dissociation

  20. Occipital bending (Yakovlevian torque) in bipolar depression.

    Science.gov (United States)

    Maller, Jerome J; Anderson, Rodney; Thomson, Richard H; Rosenfeld, Jeffrey V; Daskalakis, Zafiris J; Fitzgerald, Paul B

    2015-01-30

    Differing levels of occipital lobe asymmetry and enlarged lateral ventricles have been reported within patients with bipolar disorder (BD) compared with healthy controls, suggesting different rates of occipital bending (OB). This may exert pressure on subcortical structures, such as the hippocampus, reduced among psychiatric patients. We investigated OB prevalence in 35 patients with BD and 36 healthy controls, and ventricular and occipital volumes. Prevalence was four times higher among BD patients (12/35 [34.3%]) than in control subjects (3/36 [8.3%]), as well as larger lateral ventricular volumes (LVVs). Furthermore, we found OB to relate to left-to-right ventricular and occipital lobe volume (OLV) ratios. Those with OB also had reduced left-to-right hippocampal volume ratios. The results suggest that OB is more common among BD patients than healthy subjects, and prevalent in both BD Type I and Type II patients. We posit that anomalies in neural pruning or ventricular enlargement may precipitate OB, consequently resulting in one occipital lobe twisting around the other. Although the clinical implications of these results are unclear, the study suggests that asymmetrical ventricular volume matched with a pattern of oppositely asymmetrical occipital volume is related to OB and may be a marker of psychiatric illness. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. The left dorsolateral prefrontal cortex and caudate pathway: New evidence for cue-induced craving of smokers.

    Science.gov (United States)

    Yuan, Kai; Yu, Dahua; Bi, Yanzhi; Wang, Ruonan; Li, Min; Zhang, Yajuan; Dong, Minghao; Zhai, Jinquan; Li, Yangding; Lu, Xiaoqi; Tian, Jie

    2017-09-01

    Although the activation of the prefrontal cortex (PFC) and the striatum had been found in smoking cue induced craving task, whether and how the functional interactions and white matter integrity between these brain regions contribute to craving processing during smoking cue exposure remains unknown. Twenty-five young male smokers and 26 age- and gender-matched nonsmokers participated in the smoking cue-reactivity task. Craving related brain activation was extracted and psychophysiological interactions (PPI) analysis was used to specify the PFC-efferent pathways contributed to smoking cue-induced craving. Diffusion tensor imaging (DTI) and probabilistic tractography was used to explore whether the fiber connectivity strength facilitated functional coupling of the circuit with the smoking cue-induced craving. The PPI analysis revealed the negative functional coupling of the left dorsolateral prefrontal cortex (DLPFC) and the caudate during smoking cue induced craving task, which positively correlated with the craving score. Neither significant activation nor functional connectivity in smoking cue exposure task was detected in nonsmokers. DTI analyses revealed that fiber tract integrity negatively correlated with functional coupling in the DLPFC-caudate pathway and activation of the caudate induced by smoking cue in smokers. Moreover, the relationship between the fiber connectivity integrity of the left DLPFC-caudate and smoking cue induced caudate activation can be fully mediated by functional coupling strength of this circuit in smokers. The present study highlighted the left DLPFC-caudate pathway in smoking cue-induced craving in smokers, which may reflect top-down prefrontal modulation of striatal reward processing in smoking cue induced craving processing. Hum Brain Mapp 38:4644-4656, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Giant high occipital encephalocele

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    Agrawal Amit

    2016-03-01

    Full Text Available Encephaloceles are rare embryological mesenchymal developmental anomalies resulting from inappropriate ossification in skull through with herniation of intracranial contents of the sac. Encephaloceles are classified based on location of the osseous defect and contents of sac. Convexity encephalocele with osseous defect in occipital bone is called occipital encephalocele. Giant occipital encephaloceles can be sometimes larger than the size of baby skull itself and they pose a great surgical challenge. Occipital encephaloceles (OE are further classified as high OE when defect is only in occipital bone above the foramen magnum, low OE when involving occipital bone and foramen magnum and occipito-cervical when there involvement of occipital bone, foramen magnum and posterior upper neural arches. Chiari III malformation can be associated with high or low occipital encephaloceles. Pre-operatively, it is essential to know the size of the sac, contents of the sac, relation to the adjacent structures, presence or absence of venous sinuses/vascular structures and osseous defect size. Sometimes it becomes imperative to perform both CT and MRI for the necessary information. Volume rendered CT images can depict the relation of osseous defect to foramen magnum and provide information about upper neural arches which is necessary in classifying these lesions.

  3. Epileptiform transients of the occipital lobe in pediatrics.

    Science.gov (United States)

    Campbell, Stefan

    2013-09-01

    Differentiating between benign occipital transients and epileptic discharges from the occipital lobes is imperative. Focal occipital spikes and sharp waves are not always associated with benign disorders. The occurrence of occipital spikes and spike and wave complexes depends on the child's age, the maturation of the occipital cortex, and the cortex's connection with other structures (Beaumanoir et al. 1993). Clinical manifestations also evolve as the patient ages. Seizure semiology is due to the maturation of the visual system and its connections. An infant from birth to twelve months of age could experience autonomic symptoms such as pallor and vomiting with possible minor motor movements. Visual symptoms and/or headaches are usually not noticed until between five and seven years of age. These visual phenomena can continue into adulthood.

  4. Occipital bending in depression.

    Science.gov (United States)

    Maller, Jerome J; Thomson, Richard H S; Rosenfeld, Jeffrey V; Anderson, Rodney; Daskalakis, Zafiris J; Fitzgerald, Paul B

    2014-06-01

    There are reports of differences in occipital lobe asymmetry within psychiatric populations when compared with healthy control subjects. Anecdotal evidence and enlarged lateral ventricles suggests that there may also be a different pattern of curvature whereby one occipital lobe wraps around the other, termed 'occipital bending'. We investigated the prevalence of occipital bending in 51 patients with major depressive disorder (males mean age = 41.96 ± 14.00 years, females mean age = 40.71 ± 12.41 years) and 48 age- and sex-matched healthy control subjects (males mean age = 40.29 ± 10.23 years, females mean age = 42.47 ± 14.25 years) and found the prevalence to be three times higher among patients with major depressive disorder (18/51, 35.3%) when compared with control subjects (6/48, 12.5%). The results suggest that occipital bending is more common among patients with major depressive disorder than healthy subjects, and that occipital asymmetry and occipital bending are separate phenomena. Incomplete neural pruning may lead to the cranial space available for brain growth being restricted, or ventricular enlargement may exacerbate the natural occipital curvature patterns, subsequently causing the brain to become squashed and forced to 'wrap' around the other occipital lobe. Although the clinical implications of these results are unclear, they provide an impetus for further research into the relevance of occipital bending in major depression disorder. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

    Science.gov (United States)

    Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W

    2015-01-01

    Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. A Proton Magnetic Resonance Spectroscopic Study in Autism Spectrum Disorder Using a 3-Tesla Clinical Magnetic Resonance Imaging (MRI) System: The Anterior Cingulate Cortex and the Left Cerebellum.

    Science.gov (United States)

    Ito, Hiromichi; Mori, Kenji; Harada, Masafumi; Hisaoka, Sonoka; Toda, Yoshihiro; Mori, Tatsuo; Goji, Aya; Abe, Yoko; Miyazaki, Masahito; Kagami, Shoji

    2017-07-01

    The pathophysiology of autism spectrum disorder (ASD) is not fully understood. We used proton magnetic resonance spectroscopy to investigate metabolite concentration ratios in the anterior cingulate cortex and left cerebellum in ASD. In the ACC and left cerebellum studies, the ASD group and intelligence quotient- and age-matched control group consisted of 112 and 114 subjects and 65 and 45 subjects, respectively. In the ASD group, γ-aminobutyric acid (GABA)+/ creatine/phosphocreatine (Cr) was significantly decreased in the anterior cingulate cortex, and glutamate (Glu)/Cr was significantly increased and GABA+/Cr was significantly decreased in the left cerebellum compared to those in the control group. In addition, both groups showed negative correlations between Glu/Cr and GABA+/Cr in the left cerebellum, and positive correlations between GABA+/Cr in the anterior cingulate cortex and left cerebellum. ASD subjects have hypoGABAergic alterations in the anterior cingulate cortex and hyperglutamatergic/hypoGABAergic alterations in the left cerebellum.

  7. Monocular Visual Deprivation Suppresses Excitability in Adult Human Visual Cortex

    DEFF Research Database (Denmark)

    Lou, Astrid Rosenstand; Madsen, Kristoffer Hougaard; Paulson, Olaf Bjarne

    2011-01-01

    The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... of visual deprivation has a substantial impact on experience-dependent plasticity of the human visual cortex.......The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... employed TMS to trace plastic changes in adult visual cortex before, during, and after 48 h of monocular deprivation (MD) of the right dominant eye. In healthy adult volunteers, MD-induced changes in visual cortex excitability were probed with paired-pulse TMS applied to the left and right occipital cortex...

  8. Unimodal and multimodal regions for logographic language processing in left ventral occipitotemporal cortex

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    Yuan eDeng

    2013-09-01

    Full Text Available The human neocortex appears to contain a dedicated visual word form area (VWFA and an adjacent multimodal (visual/auditory area. However, these conclusions are based on functional magnetic resonance imaging (fMRI of alphabetic language processing, languages that have clear grapheme-to-phoneme correspondence (GPC rules that make it difficult to disassociate visual-specific processing from form-to-sound mapping. In contrast, the Chinese language has no clear GPC rules. Therefore, the current study examined whether native Chinese readers also have the same VWFA and multimodal area. Two cross-modal tasks, phonological retrieval of visual words and orthographic retrieval of auditory words, were adopted. Different task requirements were also applied to explore how different levels of cognitive processing modulate activation of putative VWFA-like and multimodal-like regions. Results showed that the left occipitotemporal sulcus responded exclusively to visual inputs and an adjacent region, the left inferior temporal gyrus, showed comparable activation for both visual and auditory inputs. Surprisingly, processing levels did not significantly alter activation of these two regions. These findings indicated that there are both unimodal and multimodal word areas for non-alphabetic language reading, and that activity in these two word-specific regions are independent of task demands at the linguistic level.

  9. Occipital lobe infarction and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, Koichi; Nagata, Ken; Shishido, Fumio (Research Inst. of Brain and Blood Vessels, Akita (Japan))

    1990-08-01

    Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alesia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blidness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exibited cerebral color blindness and posopagnosia. (author).

  10. Occipital lobe infarction and positron emission tomography

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Nagata, Ken; Shishido, Fumio

    1990-01-01

    Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alesia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blidness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exibited cerebral color blindness and posopagnosia. (author)

  11. rTMS on left prefrontal cortex contributes to memories for positive emotional cues: a comparison between pictures and words.

    Science.gov (United States)

    Balconi, M; Cobelli, C

    2015-02-26

    The present research explored the cortical correlates of emotional memories in response to words and pictures. Subjects' performance (Accuracy Index, AI; response times, RTs; RTs/AI) was considered when a repetitive Transcranial Magnetic Stimulation (rTMS) was applied on the left dorsolateral prefrontal cortex (LDLPFC). Specifically, the role of LDLPFC was tested by performing a memory task, in which old (previously encoded targets) and new (previously not encoded distractors) emotional pictures/words had to be recognized. Valence (positive vs. negative) and arousing power (high vs. low) of stimuli were also modulated. Moreover, subjective evaluation of emotional stimuli in terms of valence/arousal was explored. We found significant performance improving (higher AI, reduced RTs, improved general performance) in response to rTMS. This "better recognition effect" was only related to specific emotional features, that is positive high arousal pictures or words. Moreover no significant differences were found between stimulus categories. A direct relationship was also observed between subjective evaluation of emotional cues and memory performance when rTMS was applied to LDLPFC. Supported by valence and approach model of emotions, we supposed that a left lateralized prefrontal system may induce a better recognition of positive high arousal words, and that evaluation of emotional cue is related to prefrontal activation, affecting the recognition memories of emotions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Left occipitotemporal cortex contributes to the discrimination of tool-associated hand actions: fMRI and TMS evidence

    Directory of Open Access Journals (Sweden)

    Francesca ePerini

    2014-08-01

    Full Text Available Functional neuroimaging studies have implicated the left lateral occipitotemporal cortex (LOTC in both tool and hand perception but the functional role of this region is not fully known. Here, by using a task manipulation, we tested whether tool-/hand-selective LOTC contributes to the discrimination of tool-associated hand actions. Participants viewed briefly presented pictures of kitchen and garage tools while they performed one of two tasks: in the action task, they judged whether the tool is associated with a hand rotation action (e.g., screwdriver or a hand squeeze action (e.g., garlic press, while in the location task they judged whether the tool is typically found in the kitchen (e.g., garlic press or in the garage (e.g., screwdriver. Both tasks were performed on the same stimulus set and were matched for difficulty. Contrasting fMRI responses between these tasks showed stronger activity during the action task than the location task in both tool- and hand-selective LOTC regions, which closely overlapped. No differences were found in nearby object- and motion-selective control regions. Importantly, these findings were confirmed by a TMS study, which showed that effective TMS over the tool-/hand-selective LOTC region significantly slowed responses for tool action discriminations relative to tool location discriminations, with no such difference during sham TMS. We conclude that left LOTC contributes to the discrimination of tool-associated hand actions.

  13. Left occipitotemporal cortex contributes to the discrimination of tool-associated hand actions: fMRI and TMS evidence.

    Science.gov (United States)

    Perini, Francesca; Caramazza, Alfonso; Peelen, Marius V

    2014-01-01

    Functional neuroimaging studies have implicated the left lateral occipitotemporal cortex (LOTC) in both tool and hand perception but the functional role of this region is not fully known. Here, by using a task manipulation, we tested whether tool-/hand-selective LOTC contributes to the discrimination of tool-associated hand actions. Participants viewed briefly presented pictures of kitchen and garage tools while they performed one of two tasks: in the action task, they judged whether the tool is associated with a hand rotation action (e.g., screwdriver) or a hand squeeze action (e.g., garlic press), while in the location task they judged whether the tool is typically found in the kitchen (e.g., garlic press) or in the garage (e.g., screwdriver). Both tasks were performed on the same stimulus set and were matched for difficulty. Contrasting fMRI responses between these tasks showed stronger activity during the action task than the location task in both tool- and hand-selective LOTC regions, which closely overlapped. No differences were found in nearby object- and motion-selective control regions. Importantly, these findings were confirmed by a TMS study, which showed that effective TMS over the tool-/hand-selective LOTC region significantly slowed responses for tool action discriminations relative to tool location discriminations, with no such difference during sham TMS. We conclude that left LOTC contributes to the discrimination of tool-associated hand actions.

  14. Brain Herniation in Neurofibromatosis with Dysplasia of Occipital Bone and Posterior Skull Base

    Directory of Open Access Journals (Sweden)

    Vithal Rangarajan

    2015-01-01

    Full Text Available A 22-year-old female, a known case of neurofibromatosis 1 (NF1, presented with a congenital swelling in the left occipital region. She had developed recent onset dysphagia and localized occipital headache. Neuroradiology revealed a left occipital meningoencephalocele and a left parapharyngeal meningocele. This was associated with ventriculomegaly. She was advised on cranioplasty along with duraplasty which she denied. She agreed to a lumbar-peritoneal shunt. She described a dramatic improvement in her symptoms following the lumbar-peritoneal shunt. Occipital dysplasias, though uncommon, have been reported in the literature. We review this case and its management and discuss relevant literature on occipital dysplasias in NF1.

  15. The causal role of category-specific neuronal representations in the left ventral premotor cortex (PMv) in semantic processing.

    Science.gov (United States)

    Cattaneo, Zaira; Devlin, Joseph T; Salvini, Francesca; Vecchi, Tomaso; Silvanto, Juha

    2010-02-01

    The left ventral premotor cortex (PMv) is preferentially activated by exemplars of tools, suggestive of category specificity in this region. Here we used state-dependent transcranial magnetic stimulation (TMS) to investigate the causal role of such category-specific neuronal representations in the encoding of tool words. Priming to a category name (either "Tool" or "Animal") was used with the objective of modulating the initial activation state of this region prior to application of TMS and the presentation of the target stimulus. When the target word was an exemplar of the "Tool" category, the effects of TMS applied over PMv (but not PMd) interacted with priming history by facilitating reaction times on incongruent trials while not affecting congruent trials. This congruency/TMS interaction implies that the "Tool" and "Animal" primes had a differential effect on the initial activation state of the left PMv and implies that this region is one neural locus of category-specific behavioral priming for the "Tool" category. TMS applied over PMv had no behavioral effect when the target stimulus was an exemplar of the "Animal" category, regardless of whether the target word was congruent or incongruent with the prime. That TMS applied over the left PMv interacted with a priming effect that extended from the category name ("Tool") to exemplars of that category suggests that this region contains neuronal representation associated with a specific semantic category. Our results also demonstrate that the state-dependent effects obtained in the combination of visual priming and TMS are useful in the study of higher-level cognitive functions. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  16. Comparison of Metabolite Concentrations in the Left Dorsolateral Prefrontal Cortex, the Left Frontal White Matter, and the Left Hippocampus in Patients in Stable Schizophrenia Treated with Antipsychotics with or without Antidepressants. 1H-NMR Spectroscopy Study

    Directory of Open Access Journals (Sweden)

    Dominik Strzelecki

    2015-10-01

    Full Text Available Managing affective, negative, and cognitive symptoms remains the most difficult therapeutic problem in stable phase of schizophrenia. Efforts include administration of antidepressants. Drugs effects on brain metabolic parameters can be evaluated by means of proton nuclear magnetic resonance (1H-NMR spectroscopy. We compared spectroscopic parameters in the left prefrontal cortex (DLPFC, the left frontal white matter (WM and the left hippocampus and assessed the relationship between treatment and the spectroscopic parameters in both groups. We recruited 25 patients diagnosed with schizophrenia (DSM-IV-TR, with dominant negative symptoms and in stable clinical condition, who were treated with antipsychotic and antidepressive medication for minimum of three months. A group of 25 patients with schizophrenia, who were taking antipsychotic drugs but not antidepressants, was matched. We compared metabolic parameters (N-acetylaspartate (NAA, myo-inositol (mI, glutamatergic parameters (Glx, choline (Cho, and creatine (Cr between the two groups. All patients were also assessed with the Positive and Negative Syndrome Scale (PANSS and the Calgary Depression Scale for Schizophrenia (CDSS. In patients receiving antidepressants we observed significantly higher NAA/Cr and NAA/Cho ratios within the DLPFC, as well as significantly higher mI/Cr within the frontal WM. Moreover, we noted significantly lower values of parameters associated with the glutamatergic transmission—Glx/Cr and Glx/Cho in the hippocampus. Doses of antipsychotic drugs in the group treated with antidepressants were also significantly lower in the patients showing similar severity of psychopathology.

  17. Transcranial Magnetic Stimulation over Left Inferior Frontal and Posterior Temporal Cortex Disrupts Gesture-Speech Integration.

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    Zhao, Wanying; Riggs, Kevin; Schindler, Igor; Holle, Henning

    2018-02-21

    Language and action naturally occur together in the form of cospeech gestures, and there is now convincing evidence that listeners display a strong tendency to integrate semantic information from both domains during comprehension. A contentious question, however, has been which brain areas are causally involved in this integration process. In previous neuroimaging studies, left inferior frontal gyrus (IFG) and posterior middle temporal gyrus (pMTG) have emerged as candidate areas; however, it is currently not clear whether these areas are causally or merely epiphenomenally involved in gesture-speech integration. In the present series of experiments, we directly tested for a potential critical role of IFG and pMTG by observing the effect of disrupting activity in these areas using transcranial magnetic stimulation in a mixed gender sample of healthy human volunteers. The outcome measure was performance on a Stroop-like gesture task (Kelly et al., 2010a), which provides a behavioral index of gesture-speech integration. Our results provide clear evidence that disrupting activity in IFG and pMTG selectively impairs gesture-speech integration, suggesting that both areas are causally involved in the process. These findings are consistent with the idea that these areas play a joint role in gesture-speech integration, with IFG regulating strategic semantic access via top-down signals acting upon temporal storage areas. SIGNIFICANCE STATEMENT Previous neuroimaging studies suggest an involvement of inferior frontal gyrus and posterior middle temporal gyrus in gesture-speech integration, but findings have been mixed and due to methodological constraints did not allow inferences of causality. By adopting a virtual lesion approach involving transcranial magnetic stimulation, the present study provides clear evidence that both areas are causally involved in combining semantic information arising from gesture and speech. These findings support the view that, rather than being

  18. Amount of lifetime video gaming is positively associated with entorhinal, hippocampal and occipital volume.

    Science.gov (United States)

    Kühn, S; Gallinat, J

    2014-07-01

    Playing video games is a popular leisure activity among children and adults, and may therefore potentially influence brain structure. We have previously shown a positive association between probability of gray matter (GM) volume in the ventral striatum and frequent video gaming in adolescence. Here we set out to investigate structural correlates of video gaming in adulthood, as the effects observed in adolescents may reflect only a fraction of the potential neural long-term effects seen in adults. On magnetic resonance imaging (MRI) scans of 62 male adults, we computed voxel-based morphometry to explore the correlation of GM with the lifetime amount of video gaming (termed joystick years). We found a significant positive association between GM in bilateral parahippocamal region (entorhinal cortex) and left occipital cortex/inferior parietal lobe and joystick years (Pvideo game genres played, such as logic/puzzle games and platform games contributing positively, and action-based role-playing games contributing negatively. Furthermore, joystick years were positively correlated with hippocampus volume. The association of lifetime amount of video game playing with bilateral entorhinal cortex, hippocampal and occipital GM volume could reflect adaptive neural plasticity related to navigation and visual attention.

  19. Semantic encoding and retrieval in the left inferior prefrontal cortex: a functional MRI study of task difficulty and process specificity.

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    Demb, J B; Desmond, J E; Wagner, A D; Vaidya, C J; Glover, G H; Gabrieli, J D

    1995-09-01

    Prefrontal cortical function was examined during semantic encoding and repetition priming using functional magnetic resonance imaging (fMRI), a noninvasive technique for localizing regional changes in blood oxygenation, a correlate of neural activity. Words studied in a semantic (deep) encoding condition were better remembered than words studied in both easier and more difficult nonsemantic (shallow) encoding conditions, with difficulty indexed by response time. The left inferior prefrontal cortex (LIPC) (Brodmann's areas 45, 46, 47) showed increased activation during semantic encoding relative to nonsemantic encoding regardless of the relative difficulty of the nonsemantic encoding task. Therefore, LIPC activation appears to be related to semantic encoding and not task difficulty. Semantic encoding decisions are performed faster the second time words are presented. This represents semantic repetition priming, a facilitation in semantic processing for previously encoded words that is not dependent on intentional recollection. The same LIPC area activated during semantic encoding showed decreased activation during repeated semantic encoding relative to initial semantic encoding of the same words. This decrease in activation during repeated encoding was process specific; it occurred when words were semantically reprocessed but not when words were nonsemantically reprocessed. The results were apparent in both individual and averaged functional maps. These findings suggest that the LIPC is part of a semantic executive system that contributes to the on-line retrieval of semantic information.

  20. Beta Peak Frequencies at Rest Correlate with Endogenous GABA+/Cr Concentrations in Sensorimotor Cortex Areas.

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    Thomas J Baumgarten

    Full Text Available Neuronal oscillatory activity in the beta band (15-30 Hz is a prominent signal within the human sensorimotor cortex. Computational modeling and pharmacological modulation studies suggest an influence of GABAergic interneurons on the generation of beta band oscillations. Accordingly, studies in humans have demonstrated a correlation between GABA concentrations and power of beta band oscillations. It remains unclear, however, if GABA concentrations also influence beta peak frequencies and whether this influence is present in the sensorimotor cortex at rest and without pharmacological modulation. In the present study, we investigated the relation between endogenous GABA concentration (measured by magnetic resonance spectroscopy and beta oscillations (measured by magnetoencephalography at rest in humans. GABA concentrations and beta band oscillations were measured for left and right sensorimotor and occipital cortex areas. A significant positive linear correlation between GABA concentration and beta peak frequency was found for the left sensorimotor cortex, whereas no significant correlations were found for the right sensorimotor and the occipital cortex. The results show a novel connection between endogenous GABA concentration and beta peak frequency at rest. This finding supports previous results that demonstrated a connection between oscillatory beta activity and pharmacologically modulated GABA concentration in the sensorimotor cortex. Furthermore, the results demonstrate that for a predominantly right-handed sample, the correlation between beta band oscillations and endogenous GABA concentrations is evident only in the left sensorimotor cortex.

  1. Beta Peak Frequencies at Rest Correlate with Endogenous GABA+/Cr Concentrations in Sensorimotor Cortex Areas

    Science.gov (United States)

    Baumgarten, Thomas J.; Oeltzschner, Georg; Hoogenboom, Nienke; Wittsack, Hans-Jörg; Schnitzler, Alfons; Lange, Joachim

    2016-01-01

    Neuronal oscillatory activity in the beta band (15–30 Hz) is a prominent signal within the human sensorimotor cortex. Computational modeling and pharmacological modulation studies suggest an influence of GABAergic interneurons on the generation of beta band oscillations. Accordingly, studies in humans have demonstrated a correlation between GABA concentrations and power of beta band oscillations. It remains unclear, however, if GABA concentrations also influence beta peak frequencies and whether this influence is present in the sensorimotor cortex at rest and without pharmacological modulation. In the present study, we investigated the relation between endogenous GABA concentration (measured by magnetic resonance spectroscopy) and beta oscillations (measured by magnetoencephalography) at rest in humans. GABA concentrations and beta band oscillations were measured for left and right sensorimotor and occipital cortex areas. A significant positive linear correlation between GABA concentration and beta peak frequency was found for the left sensorimotor cortex, whereas no significant correlations were found for the right sensorimotor and the occipital cortex. The results show a novel connection between endogenous GABA concentration and beta peak frequency at rest. This finding supports previous results that demonstrated a connection between oscillatory beta activity and pharmacologically modulated GABA concentration in the sensorimotor cortex. Furthermore, the results demonstrate that for a predominantly right-handed sample, the correlation between beta band oscillations and endogenous GABA concentrations is evident only in the left sensorimotor cortex. PMID:27258089

  2. Clinico-anatomical correlations of left posterior cerebral artery occlusion

    International Nuclear Information System (INIS)

    Isono, Osamu; Shiota, Junichi; Kawamura, Mitsuru; Hirayama, Keizou; Maki, Toshiyuki.

    1988-01-01

    The relation between neurological signs and symptoms and computed tomography (CT) and magnetic resonance imaging (MRI) was examined in 11 cases of occlusion of the left posterior cerebral artery. All the patients were righthanded. Right homonimous hemianopia was noted in 8 cases, right upper quadrantanopia in 2 cases, and right lower quadrantanopia in 1 case. Of the 11 cases, alexia without agraphia was noted in 9 cases, all 9 of which showed lesions of inferior occipital cortex (lingual and fusiform gyri) and subjacent white matter. Lesions of splenium were found in only 5 of the cases of alexia without agraphia. In 2 cases with neither alexia nor agraphia, lesions were seen in the medial occipital cortex and the subjacent white matter but not in the inferior occipital lobe. Three patients had color anomia which was accompanied by memory disturbances and alexia without agraphia. In 2 of these 3, lesions were widespread in the region of the left posterior cerebral artery. Memory disturbances were observed in 6 cases, all of which also showed alexia without agraphia. The lesions extended not only of the inferior surface of the occipital lobe and along the interhemispheric fissure, but also of hippocampal and parahippocampal gyri. In 3 cases of alexia without agraphia in which no memory distrubance was found, the symptoms of alexia were slight and disappeared at an early stage. (J.P.N.)

  3. Anodal transcranial direct current stimulation of the left dorsolateral prefrontal cortex enhances emotion recognition in depressed patients and controls.

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    Brennan, Sean; McLoughlin, Declan M; O'Connell, Redmond; Bogue, John; O'Connor, Stephanie; McHugh, Caroline; Glennon, Mark

    2017-05-01

    Transcranial direct current stimulation (tDCS) can enhance a range of neuropsychological functions but its efficacy in addressing clinically significant emotion recognition deficits associated with depression is largely untested. A randomized crossover placebo controlled study was used to investigate the effects of tDCS over the left dorsolateral prefrontal cortex (L-DLPFC) on a range of neuropsychological variables associated with depression as well as neural activity in the associated brain region. A series of computerized tests was administered to clinical (n = 17) and control groups (n = 20) during sham and anodal (1.5 mA) stimulation. Anodal tDCS led to a significant main effect for overall emotion recognition (p = .02), with a significant improvement in the control group (p = .04). Recognition of disgust was significantly greater in the clinical group (p = .01). Recognition of anger was significantly improved for the clinical group (p = .04) during anodal stimulation. Differences between groups for each of the six emotions at varying levels of expression found that at 40% during anodal stimulation, happy recognition significantly improved for the clinical group (p = .01). Anger recognition at 80% during anodal stimulation significantly improved for the clinical group (p = .02). These improvements were observed in the absence of any change in psychomotor speed or trail making ability during anodal stimulation. Working memory significantly improved during anodal stimulation for the clinical group but not for controls (p = .03). The tentative findings of this study indicate that tDCS can have a neuromodulatory effect on a range of neuropsychological variables. However, it is clear that there was a wide variation in responses to tDCS and that individual difference and different approaches to testing and stimulation have a significant impact on final outcomes. Nonetheless, tDCS remains a promising tool for future neuropsychological research.

  4. Occipital bone lacunae

    International Nuclear Information System (INIS)

    Pavlica, P.; Sciascia, R.

    1988-01-01

    Sixteen patients with lacunar alterations of the squamous occipital bone were studied in various radiographic projections; in many cases studies were also performed. In 7 cases lacunae in the cerebral fossa were observed, with an average diameter of 3 cm. These defects were due to a thinning of the inner table of the theca. In 9 cases smaller lacunae were demonstrated bilaterally, which were more radiolucent, isolated or confluent, located in the area corresponding to the internal occipital protuberance at the ridges of cruciform eminence. The latter were representative of diploic venous lakes, as the best demonstrated in lateral projection. This kind of lacunae are considered as anatomic variants, because no bone destruction is demonstrable, as confirmed by technetium scintigraphy

  5. Occipital lobe seizures and epilepsies.

    Science.gov (United States)

    Adcock, Jane E; Panayiotopoulos, Chrysostomos P

    2012-10-01

    Occipital lobe epilepsies (OLEs) manifest with occipital seizures from an epileptic focus within the occipital lobes. Ictal clinical symptoms are mainly visual and oculomotor. Elementary visual hallucinations are common and characteristic. Postictal headache occurs in more than half of patients (epilepsy-migraine sequence). Electroencephalography (EEG) is of significant diagnostic value, but certain limitations should be recognized. Occipital spikes and/or occipital paroxysms either spontaneous or photically induced are the main interictal EEG abnormalities in idiopathic OLE. However, occipital epileptiform abnormalities may also occur without clinical relationship to seizures particularly in children. In cryptogenic/symptomatic OLE, unilateral posterior EEG slowing is more common than occipital spikes. In neurosurgical series of symptomatic OLE, interictal EEG abnormalities are rarely strictly occipital. The most common localization is in the posterior temporal regions and less than one-fifth show occipital spikes. In photosensitive OLE, intermittent photic stimulation elicits (1) spikes/polyspikes confined in the occipital regions or (2) generalized spikes/polyspikes with posterior emphasis. In ictal EEG, a well-localized unifocal rhythmic ictal discharge during occipital seizures is infrequent. A bioccipital field spread to the temporal regions is common. Frequency, severity, and response to treatment vary considerably from good to intractable and progressive mainly depending on underlying causes.

  6. Network-wise cerebral blood flow redistribution after 20 Hz rTMS on left dorso-lateral prefrontal cortex.

    Science.gov (United States)

    Shang, Yuan-Qi; Xie, Jun; Peng, Wei; Zhang, Jian; Chang, Da; Wang, Ze

    2018-04-01

    The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) has been consistently shown to be beneficial for treating various neuropsychiatric or neuropsychological disorders, but its neural mechanisms still remain unclear. The purpose of this study was to measure the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF) collected from 40 young healthy subjects before and after applying 20 Hz left DLPFC rTMS or SHAM stimulations. Relative CBF (rCBF) changes before and after 20 Hz rTMS or SHAM were assessed with paired-t test. The results show that 20 Hz DLPFC rTMS induced CBF redistribution in the default mode network, including increased rCBF in left medial temporal cortex (MTC)/hippocampus, but reduced rCBF in precuneus and cerebellum. Meanwhile, SHAM stimulation didn't produce any rCBF changes. After controlling SHAM effects, only the rCBF increase in MTC/hippocampus remained. Those data suggest that the beneficial effects of high-frequency rTMS may be through a within-network rCBF redistribution. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Intramuscular Lipoma-Induced Occipital Neuralgia on the Lesser Occipital Nerve.

    Science.gov (United States)

    Han, Hyun Ho; Kim, Hak Soo; Rhie, Jong Won; Moon, Suk Ho

    2016-06-01

    Occipital neuralgia (ON) is commonly characterized by a neuralgiform headache accompanied by a paroxysmal burning sensation in the dermatome area of the greater, lesser, or third occipital nerve. The authors report a rare case of ON caused by an intramuscular lipoma originating from the lesser occipital nerve.A 52-year-old man presented with sharp pain in the left postauricular area with a 3 × 2-cm palpable mass. Computed tomography revealed a mass suspiciously resembling an intramuscular lipoma within splenius muscle. In the operation field, a protruding mass causing stretching of the lesser occipital nerve was found. After complete resection, the neuralgiform headache symptom had resolved and the intramuscular lipoma was confirmed through histopathology.Previous studies on the causes of ON have reported that variation in normal anatomic structures results in nerve compression. Occipital neuralgia, however, caused by intramuscular lipomas in splenius muscles have not been previously reported, and the dramatic resolution following surgery makes it an interesting case worth reporting.

  8. Q-Ball of Inferior Fronto-Occipital Fasciculus and Beyond

    Science.gov (United States)

    Amirbekian, Bagrat; Berger, Mitchel S.; Henry, Roland G.

    2014-01-01

    The inferior fronto-occipital fasciculus (IFOF) is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI) data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA) color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the “classical” fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a) diffuse projections in the frontal lobe, b) fronto-parietal lobes connections trough the external capsule in almost all the subjects and c) widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function. PMID:24945305

  9. Q-ball of inferior fronto-occipital fasciculus and beyond.

    Directory of Open Access Journals (Sweden)

    Eduardo Caverzasi

    Full Text Available The inferior fronto-occipital fasciculus (IFOF is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the "classical" fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a diffuse projections in the frontal lobe, b fronto-parietal lobes connections trough the external capsule in almost all the subjects and c widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function.

  10. Complications of occipital bone pneumatization

    International Nuclear Information System (INIS)

    Moss, Mary; Roche, Jim; Biggs, Michael; Forer, Martin; Fagan, Paul; Davis, Martin

    2004-01-01

    Four cases of occipital bone pneumatization and subsequent complications are described, which include a pathological fracture of C 1 and the occipital bone, spontaneous subcutaneous emphysema and pneumatocele formation. Reviews of the published literature and possible aetiological factors have been discussed Copyright (2004) Blackwell Publishing Asia Pty Ltd

  11. Fracture of the occipital condyle

    International Nuclear Information System (INIS)

    Wessels, L.S.

    1990-01-01

    The term fracture of the occipital condyle is a misnomer and and usually represents an extensive fracture of the posterior fossa skull base extending onto the squamous portion of the occipital bone and even further forward. These fractures should be suspected when the lower cranial nerves are affected after severe cranial trauma. Conservative management appears to be indicated. 2 figs., 5 refs

  12. Short-Term Memory Impairment and Left Dorsolateral Prefrontal Cortex Dysfunction in the Orthostatic Position: A Single Case Study of Sinking Skin Flap Syndrome

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    Luca Sebastianelli

    2015-01-01

    Full Text Available We describe the case of a patient who underwent craniectomy for hemorrhage of the left parietal lobe. Three weeks later, orthostatic memory impairment was detected as initial symptom of sinking skin flap syndrome (SSFS. This deficit was examined by neuropsychological testing and associated with a posture-dependent increase in the delta/alpha ratio at the F3 electrode, an electroencephalographic (EEG index related to brain hypoperfusion. This EEG spectral alteration was detected in a brain region that includes the left dorsolateral prefrontal cortex, an area known to be involved in memory processing; therefore we hypothesize that SSFS induced reversible hypoperfusion of this otherwise undamaged cortical region. Neither of these findings was present after cranioplasty. This case suggests that SSFS may induce neuropsychological deficits potentially influencing outcome in the postacute phase and is further evidence supporting the clinical benefits of early cranioplasty.

  13. Giant Occipital Intradiploic Epidermoid Cyst.

    Science.gov (United States)

    Oommen, Arun; Govindan, Jayasree; Peroor, Devan Surendran; Azeez, C Roshan; Rashmi, R; Abdul Jalal, Muhammed Jasim

    2018-01-01

    Intraparenchymal or intradiploic epidermoid cysts are very rare. Most of these cysts, when present, tend to involve the frontal and temporal lobes, and occasionally, the pineal gland or the brain stem. Here, we report a 45-year-old female, who presented with localized occipital headache and a tender occipital swelling, gradually increasing in size. She was hemodynamically and neurologically stable and did not have any focal neurological deficits. Whole skull and brain imaging revealed a well-demarcated expansile lytic lesion in the right occipital bone, which was hypointense on T1-weighted and hyperintense on both T2-weighted imaging and diffusion-weighted imaging without any contrast enhancement. The patient underwent a right occipital craniotomy and total excision of the intradiploic space occupying lesion. Histopathological examination confirmed the lytic bone lesion over occipital bone as intradiploic epidermoid cyst.

  14. Experience of Surgical Treatment for Occipital Migraine in Taiwan.

    Science.gov (United States)

    Lin, Shang-Hsi; Lin, Huwang-Chi; Jeng, Chu-Hsu; Hsieh, Cheng-Han; Lin, Yu-Hsien; Chen, Cha-Chun

    2016-03-01

    Refractory migraine surgery developed since 2003 has excellent results over the past 10 years. According to the pioneer of migraine surgery, Dr. Bahman Guyuron, 5 major surgical classifications of migraines are described in the field of plastic surgery, namely, frontal migraine, temporal migraine, rhinogenic migraine, occipital migraine, and auriculotemporal migraine. In this study, we present the preliminary surgical results of the occipital migraine surgery. A total of 22 patients with simple occipital migraines came to our outpatient clinic for help from June 2014 to February 2015. Thirteen cases were excluded owing to ineligibility for operation or other reasons. The patients who concurrently experienced other types of migraines were precluded even if they received combined migraine surgery. Therefore, 9 simple occipital migraine cases were enrolled in this study. Migraine severity was evaluated by uniform questionnaires to identify the source of migraine. Neurolysis was performed under general anesthesia, with the patient in a prone position. Postoperative conditions were evaluated at the second, fourth, sixth, and eighth weeks by posttreatment questionnaires. Of all the 9 patients, 5 experienced single-sided migraines of greater occipital nerve origin (2 left-sided and 3 right-sided cases). Two patients had bilateral migraines of greater occipital nerve origin, and unilateral right lesser occipital nerve origin was noted in one patient. The last patient had right-sided migraines of greater and lesser occipital nerve origin. As a result in the follow-up, a response rate greater than 90% was documented, and complete resolution was observed in 2 patients. Drug doses were reduced more than 50% in the remaining patients. The overall efficacy of occipital migraine surgery in this study was 88.8% (8/9 cases). Some patients with migraine are good candidates for surgical resolution with appropriate and meticulous selection. Similar to what is observed in Western

  15. Human V4 and ventral occipital retinotopic maps

    Science.gov (United States)

    Winawer, Jonathan; Witthoft, Nathan

    2016-01-01

    The ventral surface of the human occipital lobe contains multiple retinotopic maps. The most posterior of these maps is considered a potential homolog of macaque V4, and referred to as human V4 (‘hV4’). The location of the hV4 map, its retinotopic organization, its role in visual encoding, and the cortical areas it borders have been the subject of considerable investigation and debate over the last 25 years. We review the history of this map and adjacent maps in ventral occipital cortex, and consider the different hypotheses for how these ventral occipital maps are organized. Advances in neuroimaging, computational modeling, and characterization of the nearby anatomical landmarks and functional brain areas have improved our understanding of where human V4 is and what kind of visual representations it contains. PMID:26241699

  16. The Medial Temporal Lobe and the Left Inferior Prefrontal Cortex Jointly Support Interference Resolution in Verbal Working Memory

    Science.gov (United States)

    Oztekin, Ilke; Curtis, Clayton E.; McElree, Brian

    2009-01-01

    During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. Participants studied six-word lists and responded to a…

  17. Transcranial Direct Current Stimulation (tDCS) Targeting Left Dorsolateral Prefrontal Cortex Modulates Task-Induced Acute Pain in Healthy Volunteers.

    Science.gov (United States)

    Mariano, Timothy Y; Van't Wout, Mascha; Garnaat, Sarah L; Rasmussen, Steven A; Greenberg, Benjamin D

    2016-04-01

    Current chronic pain treatments target nociception rather than affective "suffering" and its associated functional and psychiatric comorbidities. The left dorsolateral prefrontal cortex (DLPFC) has been implicated in affective, cognitive, and attentional aspects of pain and is a primary target of neuromodulation for affective disorders. Transcranial direct current stimulation (tDCS) can non-invasively modulate cortical activity. The present study tests whether anodal tDCS targeting the left DLPFC will increase tolerability of acute painful stimuli vs cathodal tDCS. Forty tDCS-naive healthy volunteers received anodal and cathodal stimulation targeting the left DLPFC in two randomized and counterbalanced sessions. During stimulation, each participant performed cold pressor (CP) and breath holding (BH) tasks. We measured pain intensity with the Defense and Veterans Pain Rating Scale (DVPRS) before and after each task. Mixed ANOVA revealed no main effect of stimulation polarity for mean CP threshold, tolerance, or endurance, or mean BH time (allP > 0.27). However, DVPRS rise associated with CP was significantly smaller with anodal vs cathodal tDCS (P = 0.024). We further observed a significant tDCS polarity × stimulation order interaction (P = 0.042) on CP threshold, suggesting task sensitization. Although our results do not suggest that polarity of tDCS targeting the left DLPFC differentially modulates the tolerability of CP- and BH-related pain distress in healthy volunteers, there was a significant effect on DVPRS pain ratings. This contrasts with our previous findings that tDCS targeting the left dorsal anterior cingulate cortex showed a trend toward higher mean CP tolerance with cathodal vs anodal stimulation. The present results may suggest tDCS-related effects on nociception or DLPFC-mediated attention, or preferential modulation of the affective valence of pain as captured by the DVPRS. Sham-controlled clinical studies are needed. © 2015

  18. No Effects of Stimulating the Left Ventrolateral Prefrontal Cortex with tDCS on Verbal Working Memory Updating

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    Karolina M. Lukasik

    2018-01-01

    Full Text Available The effects of transcranial direct current stimulation (tDCS on dorsolateral prefrontal cortex functions, such as working memory (WM, have been examined in a number of studies. However, much less is known about the behavioral effects of tDCS over other important WM-related brain regions, such as the ventrolateral prefrontal cortex (VLPFC. In a counterbalanced within-subjects design with 33 young healthy participants, we examined whether online and offline single-session tDCS over VLPFC affects WM updating performance as measured by a digit 3-back task. We compared three conditions: anodal, cathodal and sham. We observed no significant tDCS effects on participants' accuracy or reaction times during or after the stimulation. Neither did we find any differences between anodal and cathodal stimulation. Largely similar results were obtained when comparing subgroups of high- and low-performing participants. Possible reasons for the lack of effects, including individual differences in responsiveness to tDCS, features of montage, task and sample characteristics, and the role of VLPFC in WM, are discussed.

  19. No change in N-acetyl aspartate in first episode of moderate depression after antidepressant treatment: 1H magnetic spectroscopy study of left amygdala and left dorsolateral prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Bajs Janović M

    2014-09-01

    Full Text Available Maja Bajs Janović,1,3 Petra Kalember,2 Špiro Janović,1,3 Pero Hrabač,2 Petra Folnegović Grošić,1 Vladimir Grošić,4 Marko Radoš,5 Neven Henigsberg2,61University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, 2Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, 3University North, Varaždin, 4Psychiatric Hospital Sveti Ivan, Zagreb, 5University Department of Radiology, Clinical Hospital Center Zagreb, Zagreb, 6Psychiatric Clinic Vrapče, Zagreb, CroatiaBackground: The role of brain metabolites as biological correlates of the intensity, symptoms, and course of major depression has not been determined. It has also been inconclusive whether the change in brain metabolites, measured with proton magnetic spectroscopy, could be correlated with the treatment outcome. Methods: Proton magnetic spectroscopy was performed in 29 participants with a first episode of moderate depression occurring in the left dorsolateral prefrontal cortex and left amygdala at baseline and after 8 weeks of antidepressant treatment with escitalopram. The Montgomery-Asberg Depression Rating Scale, the Hamilton Rating Scale for Depression, and the Beck Depression Inventory were used to assess the intensity of depression at baseline and at the endpoint of the study. At endpoint, the participants were identified as responders (n=17 or nonresponders (n=12 to the antidepressant therapy. Results: There was no significant change in the N-acetyl aspartate/creatine ratio (NAA/Cr after treatment with antidepressant medication. The baseline and endpoint NAA/Cr ratios were not significantly different between the responder and nonresponder groups. The correlation between NAA/Cr and changes in the scores of clinical scales were not significant in either group. Conclusion: This study could not confirm any significant changes in NAA after antidepressant treatment in the first episode of moderate depression, or in

  20. Early (N170/M170 face-sensitivity despite right lateral occipital brain damage in acquired prosopagnosia

    Directory of Open Access Journals (Sweden)

    Esther eAlonso Prieto

    2011-12-01

    Full Text Available Compared to objects, pictures of faces elicit a larger early electromagnetic response at occipito-temporal sites on the human scalp, with an onset of 130 ms and a peak at about 170 ms. This N170 face effect is larger in the right than the left hemisphere and has been associated with the early categorization of the stimulus as a face. Here we tested whether this effect can be observed in the absence of some of the visual areas showing a preferential response to faces as typically identified in neuroimaging. Event related potentials were recorded in response to faces, cars and their phase-scrambled versions in a well-known brain-damaged case of prosopagnosia (PS. Despite the patient’s right inferior occipital gyrus lesion encompassing the most posterior cortical area showing preferential response to faces (occipital face area, OFA, we identified an early face-sensitive component over the right occipito-temporal hemisphere of the patient that was identified as the N170. A second experiment supported this conclusion, showing the typical N170 increase of latency and amplitude in response to inverted faces. In contrast, there was no N170 in the left hemisphere, where PS has a lesion to the middle fusiform gyrus and shows no evidence of face-preferential response in neuroimaging (no left fusiform face area, or lFFA. These results were replicated by a magneto-encephalographic (MEG investigation of the patient, disclosing a M170 component only in the right hemisphere. These observations indicate that face preferential activation in the inferior occipital cortex is not necessary to elicit early visual responses associated with face perception (N170/M170 on the human scalp. These results further suggest that when the right inferior occipital cortex is damaged, the integrity of the middle fusiform gyrus and/or the superior temporal sulcus – two areas showing face preferential responses in the patient’s right hemisphere - might be necessary to generate

  1. Label-free and highly sensitive optical imaging of detailed microcirculation within meninges and cortex in mice with the cranium left intact

    Science.gov (United States)

    Jia, Yali; An, Lin; Wang, Ruikang K.

    2010-05-01

    We demonstrate for the first time that the detailed blood flow distribution within intracranial dura mater and cortex can be visualized by an ultrahigh sensitive optical microangiography (UHS-OMAG). The study uses an UHS-OMAG system operating at 1310 nm with an imaging speed at 150 frames per second that requires ~10 s to complete one 3-D scan of ~2.5×2.5 mm2. The system is sensitive to blood flow with a velocity ranging from ~4 μm/s to ~23 mm/s. We show superior performance of UHS-OMAG in providing functional images of capillary level microcirculation within meninges in mice with the cranium left intact, the results of which correlate well with the standard dural histopathology.

  2. Label-free in vivo optical micro-angiography imaging of cerebral capillary blood flow within meninges and cortex in mice with the skull left intact

    Science.gov (United States)

    Jia, Yali; Wang, Ruikang K.

    2011-03-01

    Abnormal microcirculation within meninges is common in many neurological diseases. There is a need for an imaging method that is capable of visualizing functional meningeal microcirculations alone, preferably decoupled from the cortical blood flow. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing 3D images of dynamic blood perfusion within micro-circulatory tissue beds at an imaging depth up to ~2 mm, with an unprecedented imaging sensitivity to the blood flow at ~4 μm/s. In this study, we demonstrate the utility of ultra-high sensitive OMAG in imaging the detailed blood flow distributions, at a capillary level resolution, within meninges and cortex in mice with the cranium left intact. The results indicate that OMAG can be a valuable tool for the study of meningeal circulations.

  3. Impact of Anodal and Cathodal Transcranial Direct Current Stimulation over the Left Dorsolateral Prefrontal Cortex during Attention Bias Modification: An Eye-Tracking Study.

    Directory of Open Access Journals (Sweden)

    Alexandre Heeren

    Full Text Available People with anxiety disorders show an attentional bias for threat (AB, and Attention Bias Modification (ABM procedures have been found to reduce this bias. However, the underlying processes accounting for this effect remain poorly understood. One explanation suggests that ABM requires the modification of attention control, driven by the recruitment of the dorsolateral prefrontal cortex (DLPFC. In the present double-blind study, we examined whether modifying left DLPFC activation influences the effect of ABM on AB. We used transcranial direct current stimulation (tDCS to directly modulate cortical excitability of the left DLPFC during an ABM procedure designed to reduce AB to threat. Anodal tDCS increases excitability, whereas cathodal tDCS decreases it. We randomly assigned highly trait-anxious individuals to one of three conditions: 1 ABM combined with cathodal tDCS, 2 ABM combined with anodal tDCS, or 3 ABM combined with sham tDCS. We assessed the effects of these manipulations on both reaction times and eye-movements on a task indexing AB. Results indicate that combining ABM and anodal tDCS over the left DLPFC reduces the total duration that participants' gaze remains fixated on threat, as assessed using eye-tracking measurement. However, in contrast to previous studies, there were no changes in AB from baseline to post-training for participants that received ABM without tDCS. As the tendency to maintain attention to threat is known to play an important role in the maintenance of anxiety, the present findings suggest that anodal tDCS over the left DLPFC may be considered as a promising tool to reduce the maintenance of gaze to threat. Implications for future translational research combining ABM and tDCS are discussed.

  4. Cathodal transcranial direct current stimulation (tDCS) applied to the left premotor cortex (PMC) stabilizes a newly learned motor sequence.

    Science.gov (United States)

    Focke, Jan; Kemmet, Sylvia; Krause, Vanessa; Keitel, Ariane; Pollok, Bettina

    2017-01-01

    While the primary motor cortex (M1) is involved in the acquisition the premotor cortex (PMC) has been related to over-night consolidation of a newly learned motor skill. The present study aims at investigating the possible contribution of the left PMC for the stabilization of a motor sequence immediately after acquisition as determined by susceptibility to interference. Thirty six healthy volunteers received anodal, cathodal and sham transcranial direct current stimulation (tDCS) to the left PMC either immediately prior to or during training on a serial reaction time task (SRTT) with the right hand. TDCS was applied for 10min, respectively. Reaction times were measured prior to training (t1), at the end of training (t2), and after presentation of an interfering random pattern (t3). Beyond interference from learning, the random pattern served as control condition in order to estimate general effects of tDCS on reaction times. TDCS applied during SRTT training did not result in any significant effects neither on acquisition nor on susceptibility to interference. In contrast to this, tDCS prior to SRTT training yielded an unspecific facilitation of reaction times at t2 independent of tDCS polarity. At t3, reduced susceptibility to interference was found following cathodal stimulation. The results suggest the involvement of the PMC in early consolidation and reveal a piece of evidence for the hypothesis that behavioral tDCS effects vary with the activation state of the stimulated area. Copyright © 2016. Published by Elsevier B.V.

  5. Repetitive transcranial magnetic stimulation of the left premotor/dorsolateral prefrontal cortex does not have analgesic effect on central poststroke pain.

    Science.gov (United States)

    de Oliveira, Rogério Adas Ayres; de Andrade, Daniel Ciampi; Mendonça, Melina; Barros, Rafael; Luvisoto, Tatiana; Myczkowski, Martin Luiz; Marcolin, Marco Antonio; Teixeira, Manoel Jacobsen

    2014-12-01

    Central poststroke pain (CPSP) is caused by an encephalic vascular lesion of the somatosensory pathways and is commonly refractory to current pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) can change thermal pain threshold toward analgesia in healthy subjects and has analgesic effects in acute postoperative pain as well as in fibromyalgia patients. However, its effect on neuropathic pain and in CPSP, in particular, has not been assessed. The aim of this prospective, double-blind, placebo-controlled study was to evaluate the analgesic effect of PMC/DLPFC rTMS in CPSP patients. Patients were randomized into 2 groups, active (a-) rTMS and sham (s-) rTMS, and were treated with 10 daily sessions of rTMS over the left PMC/DLPFC (10 Hz, 1,250 pulses/d). Outcomes were assessed at baseline, during the stimulation phase, and at 1, 2, and 4 weeks after the last stimulation. The main outcome was pain intensity changes measured by the visual analog scale on the last stimulation day compared to baseline. Interim analysis was scheduled when the first half of the patients completed the study. The study was terminated because of a significant lack of efficacy of the active arm after 21 patients completed the whole treatment and follow-up phases. rTMS of the left PMC/DLPFC did not improve pain in CPSP. The aim of this double-blind, placebo-controlled study was to evaluate the analgesic effects of rTMS to the PMC/DLPFC in CPSP patients. An interim analysis showed a consistent lack of analgesic effect, and the study was terminated. rTMS of the PMC/DLPFC is not effective in relieving CPSP. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Developmental specialization of the left parietal cortex for the semantic representation of Arabic numerals: An fMR-adaptation study

    Directory of Open Access Journals (Sweden)

    Stephan E. Vogel

    2015-04-01

    Full Text Available The way the human brain constructs representations of numerical symbols is poorly understood. While increasing evidence from neuroimaging studies has indicated that the intraparietal sulcus (IPS becomes increasingly specialized for symbolic numerical magnitude representation over developmental time, the extent to which these changes are associated with age-related differences in symbolic numerical magnitude representation or with developmental changes in non-numerical processes, such as response selection, remains to be uncovered. To address these outstanding questions we investigated developmental changes in the cortical representation of symbolic numerical magnitude in 6- to 14-year-old children using a passive functional magnetic resonance imaging adaptation design, thereby mitigating the influence of response selection. A single-digit Arabic numeral was repeatedly presented on a computer screen and interspersed with the presentation of novel digits deviating as a function of numerical ratio (smaller/larger number. Results demonstrated a correlation between age and numerical ratio in the left IPS, suggesting an age-related increase in the extent to which numerical symbols are represented in the left IPS. Brain activation of the right IPS was modulated by numerical ratio but did not correlate with age, indicating hemispheric differences in IPS engagement during the development of symbolic numerical representation.

  7. A case of viral encephalitis localized in the occipital lobe

    International Nuclear Information System (INIS)

    Izawa, Masahiro; Okino, Teruhiko; Kagawa, Mizuo; Kitamura, Koichi.

    1987-01-01

    A case is reported of a 63-year-old female admitted to our hospital in Oct., 1986, with complaints of headache and visual field disturbance. A plain CT scan showed no abnormal low-density focal area. A contrast-enhancement CT scan, however, showed a localized linear abnormal enhancement in the right occipital lobe, without any mass-effect. A dynamic CT scan demonstrated a hyperemic perfusion pattern of the right occipital lobe. A visual-field examination showed left homonymous hemianopsia with concentric narrowing. These abnormal findings on CT, EEG, and ophthalmological examination disappeared within 3 weeks. (author)

  8. Top-down regulation of left temporal cortex by hypnotic amusia for rhythm: a pilot study on mismatch negativity.

    Science.gov (United States)

    Facco, Enrico; Ermani, Mario; Rampazzo, Patrizia; Tikhonoff, Valérie; Saladini, Marina; Zanette, Gastone; Casiglia, Edoardo; Spiegel, David

    2014-01-01

    To evaluate the effect of hypnotically induced amusia for rhythm (a condition in which individuals are unable to recognize melodies or rhythms) on mismatch negativity (MMN), 5 highly (HH) and 5 poorly (LH) hypnotizable nonmusician volunteers underwent MMN recording before and during a hypnotic suggestion for amusia. MMN amplitude was recorded using a 19-channel montage and then processed using the low-resolution electromagnetic tomography (LORETA) to localize its sources. MMN amplitude was significantly decreased during hypnotic amusia (p < .04) only in HH, where the LORETA maps of MMN showed a decreased source amplitude in the left temporal lobe, suggesting a hypnotic top-down regulation of activity of these areas and that these changes can be assessed by neurophysiological investigations.

  9. Reduced dorso-lateral prefrontal cortex in treatment resistant schizophrenia.

    Science.gov (United States)

    Zugman, André; Gadelha, Ary; Assunção, Idaiane; Sato, João; Ota, Vanessa K; Rocha, Deyvis L; Mari, Jair J; Belangero, Sintia I; Bressan, Rodrigo A; Brietzke, Elisa; Jackowski, Andrea P

    2013-08-01

    Treatment resistance affects up to one third of patients with schizophrenia (SCZ). A better understanding of its biological underlying processes could improve treatment. The aim of this study was to compare cortical thickness between non-resistant SCZ (NR-SCZ), treatment-resistant SCZ (TR-SCZ) patients and healthy controls (HC). Structural MRI scans were obtained from 3 groups of individuals: 61 treatment resistant SCZ individuals, 67 non-resistant SCZ and 80 healthy controls. Images were analyzed using cortical surface modelling (implemented in freesurfer package) to identify group differences in cortical thickness. Statistical significant differences were identified using Monte-Carlo simulation method with a corrected p-cluster<0.01. Patients in the TR-SCZ group showed a widespread reduction in cortical thickness in frontal, parietal, temporal and occipital regions bilaterally. NR-SCZ group had reduced cortex in two regions (left superior frontal cortex and left caudal middle frontal cortex). TR-SCZ group also showed decreased thickness in the left dorsolateral prefrontal cortex (DLPFC) when compared with patients from NR-SCZ group. The reduction in cortical thickness in DLPFC indicates a more severe form of the disease or a specific finding for this group. Alterations in this region should be explored as a putative marker for treatment resistance. Prospective studies, with individuals being followed from first episode psychosis until refractoriness is diagnosed, are needed to clarify these hypotheses. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. [Intracranial remote epidural haematoma as a complication after resection of an occipital lobe metastatic tumour from a testicular embryonal carcinoma – a case report].

    Science.gov (United States)

    Andrusewicz, Wojciech; Limanówka, Bartosz; Sagan, Leszek; Kojder, Ireneusz

    We present the case of a patient who suffered from intracranial epidural haematoma in the left fronto -temporo -parietal region as a complication after left parieto -occipital craniotomy and a resection of a metastatic lesion from a testicular embryonal carcinoma to the left occipital lobe. We also discuss possible causes of this complication.

  11. Differential contribution of left and right prefrontal cortex to associative cued-recall memory: a parametric PET study.

    Science.gov (United States)

    Lepage, Martin

    2004-03-01

    Several brain imaging studies have implicated prefrontal regions bilaterally during cued-recall memory tasks and yet the functional significance of these regions remains poorly understood. Using PET, we examined the neural activity in prefrontal regions of 15 subjects while they performed three cued-recall tasks differing in pre-experimental semantic associations between cues and targets. This manipulation produced varying levels of retrieval performance when one member (a semantic category name) of the triad was used as a cue for the retrieval of the other two members. The percentage of items correctly recalled was 10, 46, and 70 in the low, medium, and high cued-recall conditions, respectively. Linear contrast analyses of the PET data identified brain regions where neural activity varied with the number of items retrieved from memory. A left lateral prefrontal region showed maximal activity during the high cued-recall condition, which likely reflects processes involved in retrieval success and possibly in the generation of memory responses. Three right prefrontal regions (anterior and dorsolateral) showed maximal activity during the low cued-recall condition, which likely reflects processes involved in memory search/monitoring. These findings add further support for a bilateral prefrontal contribution to memory cued-recall tasks and point to differential roles of the two hemispheres.

  12. A computed tomography morphometric study of occipital bone and C2 pedicle anatomy for occipital-cervical fusion.

    Science.gov (United States)

    King, Nicolas K K; Rajendra, Tiruchelvarayan; Ng, Ivan; Ng, Wai Hoe

    2014-01-01

    Occipital-cervical fusion (OCF) has been used to treat instability of the occipito-cervical junction and to provide biomechanical stability after decompressive surgery. The specific areas that require detailed morphologic knowledge to prevent technical failures are the thickness of the occipital bone and diameter of the C2 pedicle, as the occipital midline bone and the C2 pedicle have structurally the strongest bone to provide the biomechanical purchase for cranio-cervical instrumentation. The aim of this study was to perform a quantitative morphometric analysis using computed tomography (CT) to determine the variability of the occipital bone thickness and C2 pedicle thickness to optimize screw placement for OCF in a South East Asian population. Thirty patients undergoing cranio-cervical junction instrumentation during the period 2008-2010 were included. The thickness of the occipital bone and the length and diameter of the C2 pedicle were measured based on CT. The thickest point on the occipital bone was in the midline with a maximum thickness below the external occipital protuberance of 16.2 mm (±3.0 mm), which was thicker than in the Western population. The average C2 pedicle diameter was 5.3 mm (±2.0 mm). This was smaller than Western population pedicle diameters. The average length of the both pedicles to the midpoint of the C2 vertebral body was 23.5 mm (±3.3 mm on the left and ±2.3 mm on the right). The results of this first study in the South East Asian population should help guide and improve the safety in occipito-cervical region instrumentation. Thus reducing the risk of technical failures and neuro-vascular injury.

  13. Cervical myelitis presenting as occipital neuralgia.

    Science.gov (United States)

    Noh, Sang-Mi; Kang, Hyun Goo

    2018-07-01

    Occipital neuralgia is a common form of headache that is characterized by paroxysmal severe lancinating pain in the occipital nerve distribution. The exact pathophysiology is still not fully understood and occipital neuralgia often develops spontaneously. There are no specific guidelines for evaluation of patients with occipital neuralgia. Cervical spine, spinal cord and posterior neck muscle lesions can induce occipital neuralgia. Brain and spine imaging may be necessary in some cases, according to the nature of the headache or response to treatment. We report a case of cervical myelitis presenting as occipital neuralgia.

  14. Occipital Encephalocele: A Case Report

    OpenAIRE

    Aslanova, Rakhshanda; Dolgun, Zehra Nihal; Turhan, Emrah; Ökten, Sabri Berkem

    2015-01-01

    Encephalocele is a neural tube defect characterized by sac-like protrusions of the brain and the covering membranes through an opening in the skull. In this case we presented a 21-year old 20 weeks pregnant woman with fetal occipital encephalocele accompanying lemon sign, normal posterior fossa imaging and normal level of maternal serum alpha-fetoprotein (MSAFP).

  15. Childhood Falls With Occipital Impacts

    NARCIS (Netherlands)

    Atkinson, Norrell; van Rijn, Rick R.; Starling, Suzanne P.

    2017-01-01

    Falls are commonly reported in children who present with both accidental and inflicted brain injuries. Short falls rarely result in serious or life-threatening injuries. Our purpose is to describe a series of cases of short falls with occipital impact leading to subdural hemorrhage (SDH). We present

  16. Intractable Occipital Neuralgia Caused by an Entrapment in the Semispinalis Capitis

    Science.gov (United States)

    Kim, Deok-ryeong; Lee, Sang-won

    2013-01-01

    Occipital neuralgia is a rare pain syndrome characterized by periodic lancinating pain involving the occipital nerve complex. We present a unique case of entrapment of the greater occipital nerve (GON) within the semispinalis capitis, which was thought to be the cause of occipital neuralgia. A 66-year-old woman with refractory left occipital neuralgia revealed an abnormally low-loop of the left posterior inferior cerebellar artery on the magnetic resonance imaging, suggesting possible vascular compression of the upper cervical roots. During exploration, however, the GON was found to be entrapped at the perforation site of the semispinalis capitis. There was no other compression of the GON or of C1 and C2 dorsal roots in their intracranial course. Postoperatively, the patient experienced almost complete relief of typical neuralgic pain. Although occipital neuralgia has been reported to occur by stretching of the GON by inferior oblique muscle or C1-C2 arthrosis, peripheral compression in the transmuscular course of the GON in the semispinalis capitis as a cause of refractory occipital neuralgia has not been reported and this should be considered when assessing surgical options for refractory occipital neuralgia. PMID:24278663

  17. Adding Sarcosine to Antipsychotic Treatment in Patients with Stable Schizophrenia Changes the Concentrations of Neuronal and Glial Metabolites in the Left Dorsolateral Prefrontal Cortex.

    Science.gov (United States)

    Strzelecki, Dominik; Podgórski, Michał; Kałużyńska, Olga; Stefańczyk, Ludomir; Kotlicka-Antczak, Magdalena; Gmitrowicz, Agnieszka; Grzelak, Piotr

    2015-10-15

    The glutamatergic system is a key point in pathogenesis of schizophrenia. Sarcosine (N-methylglycine) is an exogenous amino acid that acts as a glycine transporter inhibitor. It modulates glutamatergic transmission by increasing glycine concentration around NMDA (N-methyl-d-aspartate) receptors. In patients with schizophrenia, the function of the glutamatergic system in the prefrontal cortex is impaired, which may promote negative and cognitive symptoms. Proton nuclear magnetic resonance (¹H-NMR) spectroscopy is a non-invasive imaging method enabling the evaluation of brain metabolite concentration, which can be applied to assess pharmacologically induced changes. The aim of the study was to evaluate the influence of a six-month course of sarcosine therapy on the concentration of metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine and γ-aminobutyric acid (GABA); mI, myo-inositol; Cr, creatine; Cho, choline) in the left dorso-lateral prefrontal cortex (DLPFC) in patients with stable schizophrenia. Fifty patients with schizophrenia, treated with constant antipsychotics doses, in stable clinical condition were randomly assigned to administration of sarcosine (25 patients) or placebo (25 patients) for six months. Metabolite concentrations in DLPFC were assessed with 1.5 Tesla ¹H-NMR spectroscopy. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS). The first spectroscopy revealed no differences in metabolite concentrations between groups. After six months, NAA/Cho, mI/Cr and mI/Cho ratios in the left DLPFC were significantly higher in the sarcosine than the placebo group. In the sarcosine group, NAA/Cr, NAA/Cho, mI/Cr, mI/Cho ratios also significantly increased compared to baseline values. In the placebo group, only the NAA/Cr ratio increased. The addition of sarcosine to antipsychotic therapy for six months increased markers of neurons viability (NAA) and neurogilal activity (mI) with simultaneous improvement

  18. Adding Sarcosine to Antipsychotic Treatment in Patients with Stable Schizophrenia Changes the Concentrations of Neuronal and Glial Metabolites in the Left Dorsolateral Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    Dominik Strzelecki

    2015-10-01

    Full Text Available The glutamatergic system is a key point in pathogenesis of schizophrenia. Sarcosine (N-methylglycine is an exogenous amino acid that acts as a glycine transporter inhibitor. It modulates glutamatergic transmission by increasing glycine concentration around NMDA (N-methyl-d-aspartate receptors. In patients with schizophrenia, the function of the glutamatergic system in the prefrontal cortex is impaired, which may promote negative and cognitive symptoms. Proton nuclear magnetic resonance (1H-NMR spectroscopy is a non-invasive imaging method enabling the evaluation of brain metabolite concentration, which can be applied to assess pharmacologically induced changes. The aim of the study was to evaluate the influence of a six-month course of sarcosine therapy on the concentration of metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine and γ-aminobutyric acid (GABA; mI, myo-inositol; Cr, creatine; Cho, choline in the left dorso-lateral prefrontal cortex (DLPFC in patients with stable schizophrenia. Fifty patients with schizophrenia, treated with constant antipsychotics doses, in stable clinical condition were randomly assigned to administration of sarcosine (25 patients or placebo (25 patients for six months. Metabolite concentrations in DLPFC were assessed with 1.5 Tesla 1H-NMR spectroscopy. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS. The first spectroscopy revealed no differences in metabolite concentrations between groups. After six months, NAA/Cho, mI/Cr and mI/Cho ratios in the left DLPFC were significantly higher in the sarcosine than the placebo group. In the sarcosine group, NAA/Cr, NAA/Cho, mI/Cr, mI/Cho ratios also significantly increased compared to baseline values. In the placebo group, only the NAA/Cr ratio increased. The addition of sarcosine to antipsychotic therapy for six months increased markers of neurons viability (NAA and neurogilal activity (mI with simultaneous

  19. Recovery of visual-field defects after occipital lobe infarction: a perimetric study.

    Science.gov (United States)

    Çelebisoy, Mehmet; Çelebisoy, Neşe; Bayam, Ece; Köse, Timur

    2011-06-01

    To assess the temporal course of homonymous visual-field defects due to occipital lobe infarction, by using automated perimetry. 32 patients with ischaemic infarction of the occipital lobe were studied prospectively, using a Humphrey Visual Field Analyser II. The visual field of each eye was divided into central, paracentral and peripheral zones. The mean visual sensitivity of each zone was calculated and used for the statistical analysis. The results of the initial examination, performed within 2 weeks of stroke, were compared with the results of the sixth-month control. The lesions were assigned to the localisations, optic radiation, striate cortex, occipital pole and occipital convexity, by MRI. A statistically significant improvement was noted, especially for the lower quadrants. Lesions of the occipital pole and convexity were not significantly associated with visual-field recovery. However, involvement of the striate cortex and extensive lesions involving all the areas studied was significantly associated with poor prognosis. Homonymous visual-field defects in our patients improved within 6 months. Restoration of the lower quadrants and especially the peripheral zones was noted. Incomplete damage to the striate cortex, which has a varying pattern of vascular supply, could explain this finding. Magnification factor theory, which is the increment of the receptive-field size of striate cortex cells with visual-field eccentricity, may explain the more significant improvement in the peripheral zones.

  20. Occipital White Matter Tracts in Human and Macaque.

    Science.gov (United States)

    Takemura, Hiromasa; Pestilli, Franco; Weiner, Kevin S; Keliris, Georgios A; Landi, Sofia M; Sliwa, Julia; Ye, Frank Q; Barnett, Michael A; Leopold, David A; Freiwald, Winrich A; Logothetis, Nikos K; Wandell, Brian A

    2017-06-01

    We compare several major white-matter tracts in human and macaque occipital lobe using diffusion magnetic resonance imaging. The comparison suggests similarities but also significant differences in the tracts. There are several apparently homologous tracts in the 2 species, including the vertical occipital fasciculus (VOF), optic radiation, forceps major, and inferior longitudinal fasciculus (ILF). There is one large human tract, the inferior fronto-occipital fasciculus, with no corresponding fasciculus in macaque. We could identify the macaque VOF (mVOF), which has been little studied. Its position is consistent with classical invasive anatomical studies by Wernicke. VOF homology is supported by similarity of the endpoints in V3A and ventral V4 across species. The mVOF fibers intertwine with the dorsal segment of the ILF, but the human VOF appears to be lateral to the ILF. These similarities and differences between the occipital lobe tracts will be useful in establishing which circuitry in the macaque can serve as an accurate model for human visual cortex. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. High-definition transcranial direct current stimulation (HD-tDCS) of left dorsolateral prefrontal cortex affects performance in Balloon Analogue Risk Task (BART).

    Science.gov (United States)

    Guo, Heng; Zhang, Zhuoran; Da, Shu; Sheng, Xiaotian; Zhang, Xichao

    2018-02-01

    Studies on risk preferences have long been of great concern and have examined the neural basis underlying risk-based decision making. However, studies using conventional transcranial direct current stimulation (tDCS) revealed that bilateral stimulation could change risk propensity with limited evidence of precisely focalized unilateral high-definition transcranial direct current stimulation (HD-tDCS). The aim of this experiment was to investigate the effect of HD-tDCS focalizing the left dorsal lateral prefrontal cortex (DLPFC) on risk-taking behavior during the Balloon Analogue Risk Task (BART). This study was designed as a between-subject, single-blind, sham-controlled experiment. University students were randomly assigned to three groups: the anodal group (F3 anode, AF3, F1, F5, FC3 returned), the cathodal group (F3 cathodal, AF3, F1, F5, FC3 returned) and the sham group. Subsequently, 1.5-mA 20-min HD-tDCS was applied during the BART, and the Positive Affect and Negative Affect Scale (PANAS), the Sensation Seeking Scale-5 (SSS-5), and the Behavioral Inhibition System and Behavioral Approach System scale (BIS/BAS) were measured as control variables. The cathodal group earned less total money than the sham group, and no significant difference was observed between the anodal group and the sham group. These results showed that, to some extent, focalized unilateral cathodal HD-tDCS on left DLPFC could change performance during risky tasks and diminish risky decision making. Further studies are needed to investigate the dose effect and electrode distribution of HD-tDCS during risky tasks and examine synchronous brain activity to show the neural basis.

  2. Alexia for Braille following bilateral occipital stroke in an early blind woman.

    Science.gov (United States)

    Hamilton, R; Keenan, J P; Catala, M; Pascual-Leone, A

    2000-02-07

    Recent functional imaging and neurophysiologic studies indicate that the occipital cortex may play a role in Braille reading in congenitally and early blind subjects. We report on a woman blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the patient was a proficient Braille reader. Following the stroke, she was no longer able to read Braille yet her somatosensory perception appeared otherwise to be unchanged. This case supports the emerging evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects.

  3. Low Dose Propofol-induced Amnesia Is Not Due to a Failure of Encoding: Left Inferior Prefrontal Cortex Is Still Active

    Science.gov (United States)

    Veselis, Robert A.; Pryor, Kane O.; Reinsel, Ruth A.; Mehta, Meghana; Pan, Hong; Johnson, Ray

    2008-01-01

    Background Propofol may produce amnesia by affecting encoding. The hypothesis that propofol weakens encoding was tested by measuring regional cerebral blood flow during verbal encoding. Methods 17 volunteer participants (12 M, 30.4±6.5 years old) had regional cerebral blood flow measured using H2O15 positron emission tomography during complex and simple encoding tasks (deep vs. shallow level of processing), to identify a region of interest in the left inferior prefrontal cortex (LIPFC). The effect of either propofol (n=6, 0.9 mcg/ml target concentration), placebo with a divided attention task (n=5), or thiopental at sedative doses (n=6, 3 mcg/ml) on regional cerebral blood flow activation in the LIPFC was tested. The divided attention task was expected to decrease activation in the LIPFC. Results Propofol did not impair encoding performance or reaction times, but impaired recognition memory of deeply encoded words 4 hours later (median recognition of 35% (17–54 interquartile) of words presented during propofol versus 65% (38–91) before drug, pdeep encoding was present in this region of interest in each group before drug (T>4.41, pprocesses. PMID:18648230

  4. Low-dose propofol-induced amnesia is not due to a failure of encoding: left inferior prefrontal cortex is still active.

    Science.gov (United States)

    Veselis, Robert A; Pryor, Kane O; Reinsel, Ruth A; Mehta, Meghana; Pan, Hong; Johnson, Ray

    2008-08-01

    Propofol may produce amnesia by affecting encoding. The hypothesis that propofol weakens encoding was tested by measuring regional cerebral blood flow during verbal encoding. Seventeen volunteer participants (12 men; aged 30.4 +/- 6.5 yr) had regional cerebral blood flow measured using H2O positron emission tomography during complex and simple encoding tasks (deep vs. shallow level of processing) to identify a region of interest in the left inferior prefrontal cortex (LIPFC). The effect of either propofol (n = 6, 0.9 microg/ml target concentration), placebo with a divided attention task (n = 5), or thiopental at sedative doses (n = 6, 3 microg/ml) on regional cerebral blood flow activation in the LIPFC was tested. The divided attention task was expected to decrease activation in the LIPFC. Propofol did not impair encoding performance or reaction times, but impaired recognition memory of deeply encoded words 4 h later (median recognition of 35% [interquartile range, 17-54%] of words presented during propofol vs. 65% [38-91%] before drug; P deep encoding was present in this region of interest in each group before drug (T > 4.41, P memory processes.

  5. Low-frequency brain stimulation to the left dorsolateral prefrontal cortex increases the negative impact of social exclusion among those high in personal distress.

    Science.gov (United States)

    Fitzgibbon, Bernadette Mary; Kirkovski, Melissa; Bailey, Neil Wayne; Thomson, Richard Hilton; Eisenberger, Naomi; Enticott, Peter Gregory; Fitzgerald, Paul Bernard

    2017-06-01

    The dorsolateral prefrontal cortex (DLPFC) is thought to play a key role in the cognitive control of emotion and has therefore, unsurprisingly, been implicated in the regulation of physical pain perception. This brain region may also influence the experience of social pain, which has been shown to activate similar neural networks as seen in response to physical pain. Here, we applied sham or active low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC, previously shown to exert bilateral effects in pain perception, in healthy participants. Following stimulation, participants played the "Cyberball Task"; an online ball-tossing game in which the subject participant is included or excluded. Compared to sham, rTMS did not modulate behavioural response to social exclusion. However, within the active rTMS group only, greater trait personal distress was related to enhanced negative outcomes to social exclusion. These results add further support to the notion that the effect of brain stimulation is not homogenous across individuals, and indicates the need to consider baseline individual differences when assessing response to brain stimulation. This seems particularly relevant in social neuroscience investigations, where trait factors may have a meaningful effect.

  6. Multiple-slice spiral CT evaluation of occipital condyle fractures

    International Nuclear Information System (INIS)

    Wang Xifu; Zhang Guixiang; Li Kang'an; Zhao Jinglong; Wang Han; Feng Yan; Zheng Linfeng

    2011-01-01

    Objective: To explore the MSCT findings of occipital condyle fracture (OCF) and improve its diagnostic accuracy. Methods: Nineteen patients with OCF, selected from 110 patients suffering high energy injuries at the craniocervical junction, were enrolled into the study. The MSCT appearances of OCFs were retrospectively analyzed by two experienced radiologists. OCF had four types: type Ⅰ was a comminuted fracture, type Ⅱ was a extension of basilar skull fracture, type Ⅲ was an avulsion fracture at the attachment site of alar ligament on occipital condyle, type Ⅳ was a fracture of mixed pattern consisting of two or more above fracture types. Results: In 19 patients, the left, right and bilateral OCFs were seen in 7, 11 cases, and 1 case, respectively. Type Ⅰ was found in one case, which was a comminution of the left occipital condyle. Type Ⅱ was found in 5 cases, which involved the middle and posterior parts of occipital condyles with 2 on the left and 3 on the right, Type Ⅲ was found in 12 cases which showed various degree of fragment displacement with 3 occurring on the left, 8 on the right, 1 involving bilateral sides, 6 involving articular surfaces and 7 accompanying by enlargement of alar ligaments. Type Ⅳ was found in one case, with coexistence of Type Ⅱ and type Ⅲ In addition, OCFs were accompanied by head and (or) cervical spine injuries in 14 cases, which included cranial fracture in 8 cases, epidural hematoma in 4 cases, subarachnoid hemorrhage in one case, cerebral contusion and laceration in one case, subfalcial hernia in one case, cervical spine fracture and dislocation in 9 cases, and so on. Conclusion: OCFs can be accurately diagnosed by MSCT, which is important for selection of treatment protocols. (authors)

  7. Occipital lobe infarctions are different

    OpenAIRE

    Naess, Halvor; Waje-Andreassen, Ulrikke; Thomassen, Lars

    2007-01-01

    Halvor Naess, Ulrikke Waje-Andreassen, Lars ThomassenDepartment of Neurology, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayObjectives: We hypothesized that occipital lobe infarctions differ from infarctions in other locations as to etiology, risk factors and prognosis among young adults.Methods: Location, etiology, risk factors and long-term outcome were evaluated among all young adults 15–49 years suffering from cerebral infarction in Hordaland County, Norw...

  8. CT diagnosis of occipital bone pacchionian depression

    International Nuclear Information System (INIS)

    Zhu Jianguo; Xu Xiaolin

    2004-01-01

    Objective: To improve the recognition of the CT findings of occipital bone pacchionian depression, in order to avoid misdiagnosis. Methods: occipital bone pacchionian depression underwent CT with plain scan and intravenous contrast enhancement in 11 cases, and then the CT findings were analyzed. Results: Occipital bone pacchionian depression situated beside the torcular herophilia in 11 cases. The depression or bone defect were found at occipital bone inner plate, they can reach diploe or outer plate and had no enhancement after contrast injection. Conclusions: CT scans play an important role in diagnosis and differential diagnosis of occipital bone pacchionian depression

  9. Large-scale remapping of visual cortex is absent in adult humans with macular degeneration

    NARCIS (Netherlands)

    Baseler, Heidi A.; Gouws, Andre; Haak, Koen V.; Racey, Christopher; Crossland, Michael D.; Tufail, Adnan; Rubin, Gary S.; Cornelissen, Frans W.; Morland, Antony B.

    The occipital lobe contains retinotopic representations of the visual field. The representation of the central retina in early visual areas (V1-3) is found at the occipital pole. When the central retina is lesioned in both eyes by macular degeneration, this region of visual cortex at the occipital

  10. The occipital lobe convexity sulci and gyri.

    Science.gov (United States)

    Alves, Raphael V; Ribas, Guilherme C; Párraga, Richard G; de Oliveira, Evandro

    2012-05-01

    The anatomy of the occipital lobe convexity is so intricate and variable that its precise description is not found in the classic anatomy textbooks, and the occipital sulci and gyri are described with different nomenclatures according to different authors. The aim of this study was to investigate and describe the anatomy of the occipital lobe convexity and clarify its nomenclature. The configurations of sulci and gyri on the lateral surface of the occipital lobe of 20 cerebral hemispheres were examined in order to identify the most characteristic and consistent patterns. The most characteristic and consistent occipital sulci identified in this study were the intraoccipital, transverse occipital, and lateral occipital sulci. The morphology of the transverse occipital sulcus and the intraoccipital sulcus connection was identified as the most important aspect to define the gyral pattern of the occipital lobe convexity. Knowledge of the main features of the occipital sulci and gyri permits the recognition of a basic configuration of the occipital lobe and the identification of its sulcal and gyral variations.

  11. Clinical study of the visual field defects caused by occipital lobe lesions.

    Science.gov (United States)

    Ogawa, Katsuhiko; Ishikawa, Hiroshi; Suzuki, Yutaka; Oishi, Minoru; Kamei, Satoshi

    2014-01-01

    The central visual field is projected to the region from the occipital tip to the posterior portion of the medial area in the striate cortex. However, central visual field disturbances have not been compared with the location of the lesions in the striate cortex. Thirteen patients with visual field defects caused by partial involvement of the striate cortex were enrolled. The lesions were classified according to their location into the anterior portion, the posterior portion of the medial area, and the occipital tip. Visual field defects were examined by the Goldmann perimetry, the Humphrey perimetry and the auto-plot tangent screen. We defined a defect within the central 10° of vision as a central visual field disturbance. The visual field defects in 13 patients were compared with the location of their lesions in the striate cortex. The medial area was involved in 7 patients with no involvement of the occipital tip. In 2 of them, peripheral homonymous hemianopia without central visual field disturbance was shown, and their lesions were located only in the anterior portion. One patient with a lesion in the posterior portion alone showed incomplete central homonymous hemianopia. Three of 4 patients with lesions located in both the anterior and posterior portions of the medial area showed incomplete central homonymous hemianopia and peripheral homonymous hemianopia. The occipital tip was involved in 6 patients. Five of them had small lesions in the occipital tip alone and showed complete central homonymous hemianopia or quadrantanopia. The other patient with a lesion in the lateral posterior portion and bilateral occipital tip lesions showed bilateral slight peripheral visual field disturbance in addition to complete central homonymous hemianopia on both sides. Lesions in the posterior portion of the medial area as well as the occipital tip caused central visual field disturbance in our study, as indicated in previous reports. Central homonymous hemianopia tended to

  12. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    International Nuclear Information System (INIS)

    Liu, Arthur K.; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-01-01

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications

  13. Occipital headaches and neuroimaging in children.

    Science.gov (United States)

    Bear, Joshua J; Gelfand, Amy A; Goadsby, Peter J; Bass, Nancy

    2017-08-01

    To investigate the common thinking, as reinforced by the International Classification of Headache Disorders, 3rd edition (beta), that occipital headaches in children are rare and suggestive of serious intracranial pathology. We performed a retrospective chart review cohort study of all patients ≤18 years of age referred to a university child neurology clinic for headache in 2009. Patients were stratified by headache location: solely occipital, occipital plus other area(s) of head pain, or no occipital involvement. Children with abnormal neurologic examinations were excluded. We assessed location as a predictor of whether neuroimaging was ordered and whether intracranial pathology was found. Analyses were performed with cohort study tools in Stata/SE 13.0 (StataCorp, College Station, TX). A total of 308 patients were included. Median age was 12 years (32 months-18 years), and 57% were female. Headaches were solely occipital in 7% and occipital-plus in 14%. Patients with occipital head pain were more likely to undergo neuroimaging than those without occipital involvement (solely occipital: 95%, relative risk [RR] 10.5, 95% confidence interval [CI] 1.4-77.3; occipital-plus: 88%, RR 3.7, 95% CI 1.5-9.2; no occipital pain: 63%, referent). Occipital pain alone or with other locations was not significantly associated with radiographic evidence of clinically significant intracranial pathology. Children with occipital headache are more likely to undergo neuroimaging. In the absence of concerning features on the history and in the setting of a normal neurologic examination, neuroimaging can be deferred in most pediatric patients when occipital pain is present. © 2017 American Academy of Neurology.

  14. Occipital lobe lesions result in a displacement of magnetoencephalography visual evoked field dipoles.

    Science.gov (United States)

    Pang, Elizabeth W; Chu, Bill H W; Otsubo, Hiroshi

    2014-10-01

    The pattern-reversal visual evoked potential measured electrically from scalp electrodes is known to be decreased, or absent, in patients with occipital lobe lesions. We questioned whether the measurement and source analysis of the neuromagnetic visual evoked field (VEF) might offer additional information regarding visual cortex relative to the occipital lesion. We retrospectively examined 12 children (6-18 years) with occipital lesions on MRI, who underwent magnetoencephalography and ophthalmology as part of their presurgical assessment. Binocular half-field pattern-reversal VEFs were obtained in a 151-channel whole-head magnetoencephalography. Data were averaged and dipole source analyses were performed for each half-field stimulation. A significant lateral shift (P occipital lesions. Magnetoencephalography may be useful as a screening test of visual function in young patients. We discuss potential explanations for this lateral shift and emphasize the utility of adding the magnetoencephalography pattern-reversal visual evoked field protocol to the neurologic work-up.

  15. Resting-State Connectivity of the Left Frontal Cortex to the Default Mode and Dorsal Attention Network Supports Reserve in Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Nicolai Franzmeier

    2017-08-01

    Full Text Available Reserve refers to the phenomenon of relatively preserved cognition in disproportion to the extent of neuropathology, e.g., in Alzheimer’s disease. A putative functional neural substrate underlying reserve is global functional connectivity of the left lateral frontal cortex (LFC, Brodmann Area 6/44. Resting-state fMRI-assessed global LFC-connectivity is associated with protective factors (education and better maintenance of memory in mild cognitive impairment (MCI. Since the LFC is a hub of the fronto-parietal control network that regulates the activity of other networks, the question arises whether LFC-connectivity to specific networks rather than the whole-brain may underlie reserve. We assessed resting-state fMRI in 24 MCI and 16 healthy controls (HC and in an independent validation sample (23 MCI/32 HC. Seed-based LFC-connectivity to seven major resting-state networks (i.e., fronto-parietal, limbic, dorsal-attention, somatomotor, default-mode, ventral-attention, visual was computed, reserve was quantified as residualized memory performance after accounting for age and hippocampal atrophy. In both samples of MCI, LFC-activity was anti-correlated with the default-mode network (DMN, but positively correlated with the dorsal-attention network (DAN. Greater education predicted stronger LFC-DMN-connectivity (anti-correlation and LFC-DAN-connectivity. Stronger LFC-DMN and LFC-DAN-connectivity each predicted higher reserve, consistently in both MCI samples. No associations were detected for LFC-connectivity to other networks. These novel results extend our previous findings on global functional connectivity of the LFC, showing that LFC-connectivity specifically to the DAN and DMN, two core memory networks, enhances reserve in the memory domain in MCI.

  16. Pseudoaneurysm of the occipital artery: an unusual cause of persisting headache after minor head injury.

    LENUS (Irish Health Repository)

    Aquilina, K

    2012-02-03

    Post-traumatic pseudoaneurysms of the extracranial arteries in the scalp are uncommon sequelae of head injury. We report on a patient who presented four weeks after a minor head injury with a tender, pulsating and enlarging mass in the course of the left occipital artery. There was associated headache radiating to the vertex. Computed tomographic angiography confirmed the lesion to be a pseudoaneurysm of the occipital artery. The lump was resected with complete resolution of symptoms.

  17. Decoding the content of visual short-term memory under distraction in occipital and parietal areas.

    Science.gov (United States)

    Bettencourt, Katherine C; Xu, Yaoda

    2016-01-01

    Recent studies have provided conflicting accounts regarding where in the human brain visual short-term memory (VSTM) content is stored, with strong univariate fMRI responses being reported in superior intraparietal sulcus (IPS), but robust multivariate decoding being reported in occipital cortex. Given the continuous influx of information in everyday vision, VSTM storage under distraction is often required. We found that neither distractor presence nor predictability during the memory delay affected behavioral performance. Similarly, superior IPS exhibited consistent decoding of VSTM content across all distractor manipulations and had multivariate responses that closely tracked behavioral VSTM performance. However, occipital decoding of VSTM content was substantially modulated by distractor presence and predictability. Furthermore, we found no effect of target-distractor similarity on VSTM behavioral performance, further challenging the role of sensory regions in VSTM storage. Overall, consistent with previous univariate findings, our results indicate that superior IPS, but not occipital cortex, has a central role in VSTM storage.

  18. Decoding the content of visual short-term memory under distraction in occipital and parietal areas

    Science.gov (United States)

    Bettencourt, Katherine C.; Xu, Yaoda

    2015-01-01

    Recent studies have provided conflicting accounts regarding where in the human brain visual short-term memory (VSTM) content is stored, with strong univariate fMRI responses reported in superior intraparietal sulcus (IPS) but robust multivariate decoding reported in occipital cortex. Given the continuous influx of information in everyday vision, VSTM storage under distraction is often required. We found that neither distractor presence nor predictability during the memory delay affected behavioral performance. Similarly, superior IPS exhibited consistent decoding of VSTM content across all distractor manipulations and had multivariate responses that closely tracked behavioral VSTM performance. However, occipital decoding of VSTM content was significantly modulated by distractor presence and predictability. Furthermore, we found no effect of target-distractor similarity on VSTM behavioral performance, further challenging the role of sensory regions in VSTM storage. Overall, consistent with previous univariate findings, these results show that superior IPS, not occipital cortex, plays a central role in VSTM storage. PMID:26595654

  19. Transient facial nerve palsy after occipital nerve block: a case report.

    Science.gov (United States)

    Strauss, Lauren; Loder, Elizabeth; Rizzoli, Paul

    2014-01-01

    Occipital nerve blocks are commonly performed to treat a variety of headache syndromes and are generally believed to be safe and well tolerated. We report the case of an otherwise healthy 24-year-old woman with left side-locked occipital, parietal, and temporal pain who was diagnosed with probable occipital neuralgia. She developed complete left facial nerve palsy within minutes of blockade of the left greater and lesser occipital nerves with a solution of bupivicaine and triamcinolone. Magnetic resonance imaging of the brain with gadolinium contrast showed no abnormalities, and symptoms had completely resolved 4-5 hours later. Unintended spread of the anesthetic solution along tissue planes seems the most likely explanation for this adverse event. An aberrant course of the facial nerve or connections between the facial and occipital nerves also might have played a role, along with the patient's prone position and the use of a relatively large injection volume of a potent anesthetic. Clinicians should be aware that temporary facial nerve palsy is a possible complication of occipital nerve block. © 2014 American Headache Society.

  20. More than blindsight: Case report of a child with extraordinary visual capacity following perinatal bilateral occipital lobe injury.

    Science.gov (United States)

    Mundinano, Inaki-Carril; Chen, Juan; de Souza, Mitchell; Sarossy, Marc G; Joanisse, Marc F; Goodale, Melvyn A; Bourne, James A

    2017-11-13

    Injury to the primary visual cortex (V1, striate cortex) and the geniculostriate pathway in adults results in cortical blindness, abolishing conscious visual perception. Early studies by Larry Weiskrantz and colleagues demonstrated that some patients with an occipital-lobe injury exhibited a degree of unconscious vision and visually-guided behaviour within the blind field. A more recent focus has been the observed phenomenon whereby early-life injury to V1 often results in the preservation of visual perception in both monkeys and humans. These findings initiated a concerted effort on multiple fronts, including nonhuman primate studies, to uncover the neural substrate/s of the spared conscious vision. In both adult and early-life cases of V1 injury, evidence suggests the involvement of the Middle Temporal area (MT) of the extrastriate visual cortex, which is an integral component area of the dorsal stream and is also associated with visually-guided behaviors. Because of the limited number of early-life V1 injury cases for humans, the outstanding question in the field is what secondary visual pathways are responsible for this extraordinary capacity? Here we report for the first time a case of a child (B.I.) who suffered a bilateral occipital-lobe injury in the first two weeks postnatally due to medium-chain acyl-Co-A dehydrogenase deficiency. At 6 years of age, B.I. underwent a battery of neurophysiological tests, as well as structural and diffusion MRI and ophthalmic examination at 7 years. Despite the extensive bilateral occipital cortical damage, B.I. has extensive conscious visual abilities, is not blind, and can use vision to navigate his environment. Furthermore, unlike blindsight patients, he can readily and consciously identify happy and neutral faces and colors, tasks associated with ventral stream processing. These findings suggest significant re-routing of visual information. To identify the putative visual pathway/s responsible for this ability, MRI

  1. Analysis of occipital lobe activation during functional MRI in patients with open-angle glaucoma and correlation with clinical results

    International Nuclear Information System (INIS)

    Dai Hui; Liu Yunlian; Hu Chunhong; Li Yonggang; Guo Liang; Qi Jianpin; Xia Liming

    2013-01-01

    Objective: To evaluate the activation of the visual cortex in patients with primary open angle glaucoma (POAG) and to explore whether the neuronal activity corresponds with retinal nerve fiber layer (RNFL) and cup-to-disc (C/D) values. Methods: Twenty-five patients and 25 gender-and age matched healthy volunteers were studied. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) and three-dimensional brain volume imaging (3D BRAVO) sequences were obtained using 3 T MR imaging system. A full-screen black-white shift checkerboard was used for visual stimulus during the fMRI experiment and was performed on each eye of all subjects using a visual-acoustical system. All acquired data were postprocessed and analyzed by statistical parametric mapping (SPM). After analysis, individual activated mapping, intra-group mean activated mapping, and inter-group variant mapping were observed. The voxel number, intensity, and Montreal Neurological Institute (MNI) coordinate of the activated clusters were recorded. The Xjviewer software was utilized to obtain activated voxel numbers in occipital lobe. A Pearson correlated test was performed to test the correlation between the number of activated voxels and RNFL, C/D and Hodapp-Anderson-Parrish (HAP) clinical stage. Results: Intra-group mean activated mappings of both patients and volunteers showed obvious activation in bilateral occipital lobes. As compared with healthy volunteers, the POAG patients exhibited statistically significantly decreased activation in bilateral occipital lobes, left hippocampus, and left cerebellum, along with lower mean RNFL [(71.56 ± 21.54) μm versus (111.88 ± 9.96) μm] and higher C/D values (0.71 ± 0.18 versus 0.36 ± 0.08 ; t value was respectively -10.901 and 11.643, P 0.05). Conclusions: fMRI demonstrated differences in visual cortex activation in POAG patients relative to healthy volunteers, suggesting it might be a promising complementary method for diagnosing

  2. Primary Occipital Ewing’s Sarcoma with Subsequent Spinal Seeding

    Directory of Open Access Journals (Sweden)

    Ali Alqahtani

    2017-01-01

    Full Text Available Ewing’s sarcoma is a primary bone cancer that mainly affects the long bones. This malignancy is particularly common in pediatric patients. Primary cranial involvement accounts for 1% of cases, with occipital involvement considered extremely rare. In this case study, primary occipital Ewing’s sarcoma with a posterior fossa mass and subsequent relapse resulting in spinal seeding is reported. A 3-year-old patient presented with a 1-year history of left-sided headaches, localized over the occipital bone with progressive torticollis. Computed tomography (CT imaging showed a mass in the left posterior fossa compressing the brainstem. The patient then underwent surgical excision followed by adjuvant chemoradiation therapy. Two years later, the patient presented with severe lower back pain and urinary incontinence. Whole-spine magnetic resonance imaging (MRI showed cerebrospinal fluid (CSF seeding from the L5 to the S4 vertebrae. Primary cranial Ewing’s sarcoma is considered in the differential diagnosis of children with extra-axial posterior fossa mass associated with destructive permeative bone lesions. Although primary cranial Ewing’s sarcoma typically has good prognosis, our patient developed metastasis in the lower spine. Therefore, with CNS Ewing’s sarcoma, screening of the entire neural axis should be taken into consideration for early detection of CSF seeding metastasis in order to decrease the associated morbidity and mortality.

  3. Primary Occipital Ewing's Sarcoma with Subsequent Spinal Seeding.

    Science.gov (United States)

    Alqahtani, Ali; Amer, Roaa; Bakhsh, Eman

    2017-01-01

    Ewing's sarcoma is a primary bone cancer that mainly affects the long bones. This malignancy is particularly common in pediatric patients. Primary cranial involvement accounts for 1% of cases, with occipital involvement considered extremely rare. In this case study, primary occipital Ewing's sarcoma with a posterior fossa mass and subsequent relapse resulting in spinal seeding is reported. A 3-year-old patient presented with a 1-year history of left-sided headaches, localized over the occipital bone with progressive torticollis. Computed tomography (CT) imaging showed a mass in the left posterior fossa compressing the brainstem. The patient then underwent surgical excision followed by adjuvant chemoradiation therapy. Two years later, the patient presented with severe lower back pain and urinary incontinence. Whole-spine magnetic resonance imaging (MRI) showed cerebrospinal fluid (CSF) seeding from the L5 to the S4 vertebrae. Primary cranial Ewing's sarcoma is considered in the differential diagnosis of children with extra-axial posterior fossa mass associated with destructive permeative bone lesions. Although primary cranial Ewing's sarcoma typically has good prognosis, our patient developed metastasis in the lower spine. Therefore, with CNS Ewing's sarcoma, screening of the entire neural axis should be taken into consideration for early detection of CSF seeding metastasis in order to decrease the associated morbidity and mortality.

  4. Morphologic Analysis of Occipital Sinuses for Occipital Screw Fixation Using Digital Subtraction Angiography.

    Science.gov (United States)

    Lee, Dong Hoon; Hong, Jae Taek; Sung, Jae Hoon; Jain, Ashish; Huh, Joon; Kim, Sang Uk; Kim, Joon Young; Kwon, Jae Yoel; Cho, Chul Bum; Kim, Il Sup; Lee, Sang Won

    2016-07-01

    Numerous methods to achieve occipitocervical stabilization have been described, including the use of occipital plate/screw constructs. Bicortical screws may increase the pullout strength, but intracranial injuries to venous sinuses have been reported. This study was performed to analyze the variations in occipital sinuses to prevent sinus injury caused by the bicortical screw. Occipital sinuses of 1720 patients were examined using digital subtraction angiography. The data collected included patient age and sex, occipital sinus type, distance between occipital sinus and midline, depth from inion to occipital sinus, and distance between occipital sinus and midline occiput at different levels. The mean age of patients was 57 years ± 13. There were 807 (46.9%) men and 913 (53.1%) women. The most common occipital sinus type was single occipital sinus off-midline (type B2). The least common occipital sinus type was absent occipital sinuses (type A; 8.7% of patients). There was no significant difference between age and occipital sinus type (P = 0.310). Also, the difference between sexes was not significant in regard to occipital sinus type in general. However, in subgroup analysis of type B1 and B2, there was a significant difference between sexes (P occipital sinus was 19.913 mm ± 7.437. The occipital sinus shows several variations, and many morphologic differences can be seen. Preoperative detailed examination by magnetic resonance venography or vertebral angiography may be required for cases in which bicortical occipital screw fixation is necessary to avoid occipital sinus-related complications. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Prevention of postoperative visual field defect after the occipital transtentorial approach: anatomical study.

    Science.gov (United States)

    Matsuo, Satoshi; Baydin, Serhat; Güngör, Abuzer; Middlebrooks, Erik H; Komune, Noritaka; Iihara, Koji; Rhoton, Albert L

    2017-10-20

    OBJECTIVE A postoperative visual field defect resulting from damage to the occipital lobe during surgery is a unique complication of the occipital transtentorial approach. Though the association between patient position and this complication is well investigated, preventing the complication remains a challenge. To define the area of the occipital lobe in which retraction is least harmful, the surface anatomy of the brain, course of the optic radiations, and microsurgical anatomy of the occipital transtentorial approach were examined. METHODS Twelve formalin-fixed cadaveric adult heads were examined with the aid of a surgical microscope and 0° and 45° endoscopes. The optic radiations were examined by fiber dissection and MR tractography techniques. RESULTS The arterial and venous relationships of the lateral, medial, and inferior surfaces of the occipital lobe were defined anatomically. The full course of the optic radiations was displayed via both fiber dissection and MR tractography. Although the stems of the optic radiations as exposed by both techniques are similar, the terminations of the fibers are slightly different. The occipital transtentorial approach provides access for the removal of lesions involving the splenium, pineal gland, collicular plate, cerebellomesencephalic fissure, and anterosuperior part of the cerebellum. An angled endoscope can aid in exposing the superior medullary velum and superior cerebellar peduncles. CONCLUSIONS Anatomical findings suggest that retracting the inferior surface of the occipital lobe may avoid direct damage and perfusion deficiency around the calcarine cortex and optic radiations near their termination. An accurate understanding of the course of the optic radiations and vascular relationships around the occipital lobe and careful retraction of the inferior surface of the occipital lobe may reduce the incidence of postoperative visual field defect.

  6. The impact of occipital lobe cortical thickness on cognitive task performance: An investigation in Huntington's Disease.

    Science.gov (United States)

    Johnson, Eileanoir B; Rees, Elin M; Labuschagne, Izelle; Durr, Alexandra; Leavitt, Blair R; Roos, Raymund A C; Reilmann, Ralf; Johnson, Hans; Hobbs, Nicola Z; Langbehn, Douglas R; Stout, Julie C; Tabrizi, Sarah J; Scahill, Rachael I

    2015-12-01

    The occipital lobe is an important visual processing region of the brain. Following consistent findings of early neural changes in the occipital lobe in Huntington's Disease (HD), we examined cortical thickness across four occipital regions in premanifest (preHD) and early HD groups compared with controls. Associations between cortical thickness in gene positive individuals and performance on six cognitive tasks, each with a visual component, were examined. In addition, the association between cortical thickness in gene positive participants and one non-visual motor task was also examined for comparison. Cortical thickness was determined using FreeSurfer on T1-weighted 3T MR datasets from controls (N=97), preHD (N=109) and HD (N=69) from the TRACK-HD study. Regression models were fitted to assess between-group differences in cortical thickness, and relationships between performance on the cognitive tasks, the motor task and occipital thickness were examined in a subset of gene-positive participants (N=141). Thickness of the occipital cortex in preHD and early HD participants was reduced compared with controls. Regionally-specific associations between reduced cortical thickness and poorer performance were found for five of the six cognitive tasks, with the strongest associations in lateral occipital and lingual regions. No associations were found with the cuneus. The non-visual motor task was not associated with thickness of any region. The heterogeneous pattern of associations found in the present study suggests that occipital thickness negatively impacts cognition, but only in regions that are linked to relatively advanced visual processing (e.g., lateral occipital, lingual regions), rather than in basic visual processing regions such as the cuneus. Our results show, for the first time, the functional implications of occipital atrophy highlighted in recent studies in HD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. [Neuroanatomy of Frontal Association Cortex].

    Science.gov (United States)

    Takada, Masahiko

    2016-11-01

    The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas. Given these facts, it is likely that the prefrontal cortex exerts executive functions for behavioral control. The functional input pathways from the posterior and paralimbic association cortical areas to the prefrontal cortex are classified primarily into six groups. Cognitive signals derived from the prefrontal cortex are conveyed to the rostral motor-related areas to transform them into motor signals, which finally enter the primary motor cortex via the caudal motor-related areas. Furthermore, it has been shown that, similar to the primary motor cortex, areas of the frontal association cortex form individual networks (known as "loop circuits") with the basal ganglia and cerebellum via the thalamus, and hence are extensively involved in the expression and control of behavioral actions.

  8. Occipital projections in the skeletal dysplasias

    International Nuclear Information System (INIS)

    Takamine, Yuji; Field, Fiona M.; Lachman, Ralph S.; Rimoin, David L.

    2004-01-01

    Occipital projections of the cranium have been reported in a number of skeletal dysplasias and syndromes. We observed two cases of atelosteogenesis type I with a bony occipital projection. This finding has neither been noted nor reported in any form of atelosteogenesis. This led us to search the International Skeletal Dysplasia Registry for occipital projections, and we found them in four other syndromes in which they had not been reported. Thus occipital spurs are a non-diagnostic feature that can be found in at least ten distinct disorders as well as a normal variant. (orig.)

  9. Occipital bone thickness: Implications on occipital-cervical fusion. A cadaveric study

    Directory of Open Access Journals (Sweden)

    Kourosh Zarghooni

    2016-12-01

    Conclusion: The measurements demonstrated a great individual variability of bone thickness of the occipital bone. The results emphasize the role of preoperative planning for the feasibility of placement of an occipital screw.

  10. Occipital alopecia following cardiopulmonary bypass.

    Science.gov (United States)

    Lwason, N W; Mills, N L; Ochsner, J L

    1976-03-01

    Postoperative alopecia is a minor complication of surgery but a cosmetic disaster to the patient. Over a 3 year period, 60 cases of occipital alopecia were discovered in patients following open-heart surgery and 5 cases on other surgical services. In contrast to previous reports, 29 patients had alopecia one year later, presumed to be permanent. Extensive operations, with prolonged recovery and elective overnight mechanical ventilation, were common to all. Retrospective analysis and prospective studies clearly demonstrated that localized scalp pressure was the cause of the alopecia and that the duration of pressure determined the extent of the damage. Moving the patient's head at regular intervals during operation and recovery eliminated the alopecia. The type of head rest used did not modify the development of alopecia. Electrical injury and the use of heparin, hypothermia, electrocautery, or hypotension were eliminated as possible causes. Conclusive evidence correlating periperative events with the formation of pressure sores in man has not been previously reported.

  11. Language networks in anophthalmia: maintained hierarchy of processing in 'visual' cortex.

    Science.gov (United States)

    Watkins, Kate E; Cowey, Alan; Alexander, Iona; Filippini, Nicola; Kennedy, James M; Smith, Stephen M; Ragge, Nicola; Bridge, Holly

    2012-05-01

    Imaging studies in blind subjects have consistently shown that sensory and cognitive tasks evoke activity in the occipital cortex, which is normally visual. The precise areas involved and degree of activation are dependent upon the cause and age of onset of blindness. Here, we investigated the cortical language network at rest and during an auditory covert naming task in five bilaterally anophthalmic subjects, who have never received visual input. When listening to auditory definitions and covertly retrieving words, these subjects activated lateral occipital cortex bilaterally in addition to the language areas activated in sighted controls. This activity was significantly greater than that present in a control condition of listening to reversed speech. The lateral occipital cortex was also recruited into a left-lateralized resting-state network that usually comprises anterior and posterior language areas. Levels of activation to the auditory naming and reversed speech conditions did not differ in the calcarine (striate) cortex. This primary 'visual' cortex was not recruited to the left-lateralized resting-state network and showed high interhemispheric correlation of activity at rest, as is typically seen in unimodal cortical areas. In contrast, the interhemispheric correlation of resting activity in extrastriate areas was reduced in anophthalmia to the level of cortical areas that are heteromodal, such as the inferior frontal gyrus. Previous imaging studies in the congenitally blind show that primary visual cortex is activated in higher-order tasks, such as language and memory to a greater extent than during more basic sensory processing, resulting in a reversal of the normal hierarchy of functional organization across 'visual' areas. Our data do not support such a pattern of organization in anophthalmia. Instead, the patterns of activity during task and the functional connectivity at rest are consistent with the known hierarchy of processing in these areas

  12. [The occipital sinus: a radioanatomic study].

    Science.gov (United States)

    Gaumont-Darcissac, M; Viart, L; Foulon, P; Le Gars, D; Havet, E; Peltier, J

    2015-03-01

    The aim of this study was to assess the presence of an occipital sinus in both children and adults, and to detail its main associated anatomical characteristics. One hundred of patients' MRI (3D T1 EG) between 0 and 86 years old were studied, in sagittal and axial sections, with the software DxMM. Occipital sinus length, perimeter, and cerebellar falx length measurements were performed with the software's tools. Forty-three percent of patients had an occipital sinus (average perimeter was 3.02 mm, average length was 19.85 mm), and 23.26% of these patients had a cerebellar falx, 30.23% of these patients had one vein or more draining into the occipital sinus. Sixty-two percent of children had an occipital sinus (average perimeter was 2.87 mm, average length was 21.63 mm), and 29.03% of them had a cerebellar falx. Twenty-four percent of adults had an occipital sinus (average perimeter was 3.4mm, average length was 15.28 mm), and 8.33% of them had a cerebellar falx. This work highlights a link between the age and the occipital sinus existence. The perimeter of this sinus seems to be superior for adults, but its length seems to be superior for children. A cerebellar falx with the occipital sinus was found more frequently for children. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Charles Bonnet Syndrome in a Patient With Right Medial Occipital Lobe Infarction: Epileptic or Deafferentation Phenomenon?

    Science.gov (United States)

    Kumral, Emre; Uluakay, Arzu; Dönmez, İlknur

    2015-07-01

    Charles Bonnet syndrome (CBS) is an uncommon disorder characterized by complex and recurrent visual hallucinations in patients with visual pathway pathologic defects. To describe a patient who experienced complex visual hallucinations following infarction in the right occipital lobe and epileptic seizure who was diagnosed as having CBS. A 65-year-old man presented acute ischemic stroke caused by artery to artery embolism involving the right occipital lobe. Following ischemic stroke, complex visual hallucinations in the left visual field not associated with loss of consciousness or delusion developed in the patient. Hallucinations persisted for >1 month and during hallucination, no electrographic seizures were recorded through 24 hours of videoelectroencephalographic monitoring. CBS may develop in a patient with occipital lobe infarction following an embolic event. CBS associated with medial occipital lobe infarction and epilepsy may coexist and reflects the abnormal functioning of an integrated neuronal network.

  14. Alterations of the occipital lobe in schizophrenia.

    Science.gov (United States)

    Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

    2015-07-01

    The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia.

  15. Alterations of the occipital lobe in schizophrenia

    Science.gov (United States)

    Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

    2015-01-01

    The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia. PMID:26166588

  16. Is there a role of visual cortex in spatial hearing?

    Science.gov (United States)

    Zimmer, Ulrike; Lewald, Jörg; Erb, Michael; Grodd, Wolfgang; Karnath, Hans-Otto

    2004-12-01

    The integration of auditory and visual spatial information is an important prerequisite for accurate orientation in the environment. However, while visual spatial information is based on retinal coordinates, the auditory system receives information on sound location in relation to the head. Thus, any deviation of the eyes from a central position results in a divergence between the retinal visual and the head-centred auditory coordinates. It has been suggested that this divergence is compensated for by a neural coordinate transformation, using a signal of eye-in-head position. Using functional magnetic resonance imaging, we investigated which cortical areas of the human brain participate in such auditory-visual coordinate transformations. Sounds were produced with different interaural level differences, leading to left, right or central intracranial percepts, while subjects directed their gaze to visual targets presented to the left, to the right or straight ahead. When gaze was to the left or right, we found the primary visual cortex (V1/V2) activated in both hemispheres. The occipital activation did not occur with sound lateralization per se, but was found exclusively in combination with eccentric eye positions. This result suggests a relation of neural processing in the visual cortex and the transformation of auditory spatial coordinates responsible for maintaining the perceptual alignment of audition and vision with changes in gaze direction.

  17. The anatomy of fronto-occipital connections from early blunt dissections to contemporary tractography.

    Science.gov (United States)

    Forkel, Stephanie J; Thiebaut de Schotten, Michel; Kawadler, Jamie M; Dell'Acqua, Flavio; Danek, Adrian; Catani, Marco

    2014-07-01

    The occipital and frontal lobes are anatomically distant yet functionally highly integrated to generate some of the most complex behaviour. A series of long associative fibres, such as the fronto-occipital networks, mediate this integration via rapid feed-forward propagation of visual input to anterior frontal regions and direct top-down modulation of early visual processing. Despite the vast number of anatomical investigations a general consensus on the anatomy of fronto-occipital connections is not forthcoming. For example, in the monkey the existence of a human equivalent of the 'inferior fronto-occipital fasciculus' (iFOF) has not been demonstrated. Conversely, a 'superior fronto-occipital fasciculus' (sFOF), also referred to as 'subcallosal bundle' by some authors, is reported in monkey axonal tracing studies but not in human dissections. In this study our aim is twofold. First, we use diffusion tractography to delineate the in vivo anatomy of the sFOF and the iFOF in 30 healthy subjects and three acallosal brains. Second, we provide a comprehensive review of the post-mortem and neuroimaging studies of the fronto-occipital connections published over the last two centuries, together with the first integral translation of Onufrowicz's original description of a human fronto-occipital fasciculus (1887) and Muratoff's report of the 'subcallosal bundle' in animals (1893). Our tractography dissections suggest that in the human brain (i) the iFOF is a bilateral association pathway connecting ventro-medial occipital cortex to orbital and polar frontal cortex, (ii) the sFOF overlaps with branches of the superior longitudinal fasciculus (SLF) and probably represents an 'occipital extension' of the SLF, (iii) the subcallosal bundle of Muratoff is probably a complex tract encompassing ascending thalamo-frontal and descending fronto-caudate connections and is therefore a projection rather than an associative tract. In conclusion, our experimental findings and review of the

  18. Dandy-Walker syndrome together with occipital encephalocele.

    Science.gov (United States)

    Cakmak, A; Zeyrek, D; Cekin, A; Karazeybek, H

    2008-08-01

    Dandy-Walker malformation is an anomaly characterized by dysgenesis of the foramina of Magendie and Lushka in the upper 4(th) ventricle, hypoplasia of the cerebellar vermis and agenesis of the corpus callosum. Encephalocele is diagnosed from the calvarium defect, cerebrospinal fluid (CSF) and herniation of the meninges. It is the rarest neural tube defect. A 7 x 9 cm encephalocele was found on physical examination of a 6-day old baby boy patient. From cranial magnetic resonance, it was seen that the posterior fossa was enlarged with cysts and there was agenesis of the vermis. A connection was established between the ventricle and the development of cysts on the posterior fossa. These findings were evaluated as significant from the aspect of Dandy-Walker malformation. The extension of the bone defect in the left occipital area towards the posterior, and the cranio-caudal diameter reaching 9 cm was seen to be in accordance with encephalocele. It is rare for Dandy-Walker syndrome to occur together with occipital encephalocele. The authors present a case of Dandy-Walker syndrome together with occipital encephalocele.

  19. Neurosurgical Interventions for Occipital Encephalocele

    Science.gov (United States)

    Rehman, Lal; Farooq, Ghulam; Bukhari, Irum

    2018-01-01

    Aims and Objectives: The aim of this study is to find the outcome of repair and resection of the occipital encephalocele. Study Design: Case series. Materials and Methods: The clinical data of fifty consecutive occipital encephalocele patients were retrieved from medical records including operative notes, postoperative follow-up visits, and postsurgical complications were noted for analysis from November 2009 to November 2013 at the Department of Neurosurgery, Jinnah Postgraduate Medical Centre, Karachi, Pakistan. All patients were assessed by computed tomography scan, magnetic resonance imaging brain, and ultrasound when needed. Physician's assessment, physical examination, and his/her questions to the family at follow-up were used as a tool to determine if there was a developmental delay rather than quantitative analysis like hydrocephalus questionnaires. Patients who developed complications and delayed milestone were regarded as no improvement and those who did not develop complications and achieved appropriate milestone were regarded as improved at 18 months follow-up. Results: Of 50 patients, 17 were males and 33 were females. The average age at presentation was 2.4 months. 16 (32%) patients had increased head circumference and hydrocephalus, 2 (4%) had associated Dandy–Walker cyst, 3 (6%) developed developmental delays, and 8 (15%) had a seizure disorder. None of our patients had neurological deficits. The size of the sac ranged from 2 cm × 3 cm to 27 cm × 15 cm. 9 (18%) patients were admitted with the complication of sac rupture and 2 (4%) patients sac ruptured after admission. Only one patient (2%) had a cerebrospinal fluid leak postoperatively that was repaired primarily without patch graft or dura seal while 4 (8%) developed hydrocephalus after repair of the sac which was treated with placement of ventriculoperitoneal shunt. One (2%) patient did not recover from anesthesia and expired. Conclusion: Encephalocele is commonly seen in the practice of

  20. Morphological dissociation between visual pathways and cortex: MRI of visually-deprived patients with congenital peripheral blindness

    International Nuclear Information System (INIS)

    Breitenseher, M.; Prayer Wimberger, D.; Trattnig, S.; Kramer, J.; Uhl, F.; Deecke, L.

    1998-01-01

    MRI was used to study possible morphological changes in the visual system in 12 patients suffering from congenital blindness of peripheral (ocular) origin. While their optical pathways showed degeneration, hypoplasia or atrophy in 7 out of 12 cases, the occipital cortex appeared normal in all cases. This dissociation between afferent pathways and the cortex is contrary to the assumption that visually deprived cortex may undergo degeneration. The finding is congruent with evidence that the occipital cortex is used for other, nonvisual functions. (orig.)

  1. How does occipitalization influence the dimensions of the cranium?

    DEFF Research Database (Denmark)

    Caspersen, L M; Kjaer, I; Sonnesen, L

    2010-01-01

    To describe occipitalization on human dry skulls and to compare craniofacial morphology including the posterior cranial fossa in skulls with occipitalization and in skulls without occipitalization and with normal craniofacial morphology (controls).......To describe occipitalization on human dry skulls and to compare craniofacial morphology including the posterior cranial fossa in skulls with occipitalization and in skulls without occipitalization and with normal craniofacial morphology (controls)....

  2. Ultrasound-Guided Intermediate Site Greater Occipital Nerve Infiltration: A Technical Feasibility Study.

    Science.gov (United States)

    Zipfel, Jonathan; Kastler, Adrian; Tatu, Laurent; Behr, Julien; Kechidi, Rachid; Kastler, Bruno

    2016-01-01

    Two studies recently reported that computed tomography (CT) guided infiltration of the greater occipital nerve at its intermediate site allows a high efficacy rate with long-lasting pain relief following procedure in occipital neuralgia and in various craniofacial pain syndromes. The purpose of our study was to evaluate the technical feasibility and safety of ultrasound-guided intermediate site greater occipital nerve infiltration. Retrospective study. This study was conducted at the imaging department of a 1,409 bed university hospital. Local institutional review board approval was obtained and written consent was waived. In this retrospective study, 12 patients suffering from refractory occipital neuralgia or craniofacial pain syndromes were included between April and October 2014. They underwent a total of 21 ultrasound-guided infiltrations. Infiltration of the greater occipital nerve was performed at the intermediate site of the greater occipital nerve, at its first bend between obliqus capitis inferior and semispinalis capitis muscles with local anestetics and cortivazol. Technical success was defined as satisfactory diffusion of added iodinated contrast media in the fatty space between these muscles depicted on control CT scan. We also reported first data of immediate block test efficacy and initial clinical efficacy at 7 days, one month, and 3 months, defined by a decrease of at least 50% of visual analog scale (VAS) scores. Technical success rate was 95.24%. Patients suffered from right unilateral occipital neuralgia in 3 cases, left unilateral occipital neuralgia in 2 cases, bilateral occipital neuralgia in 2 cases, migraine in one case, cervicogenic headache in one case, tension-type headache in 2 cases, and cluster headache in one case. Block test efficacy was found in 93.3% (14/15) cases. Clinical efficacy was found in 80% of cases at 7 days, in 66.7% of cases at one month and in 60% of cases at 3 months. No major complications were noted. Some of the

  3. A simplified CT-guided approach for greater occipital nerve infiltration in the management of occipital neuralgia.

    Science.gov (United States)

    Kastler, Adrian; Onana, Yannick; Comte, Alexandre; Attyé, Arnaud; Lajoie, Jean-Louis; Kastler, Bruno

    2015-08-01

    To evaluate the efficacy of a simplified CT-guided greater occipital nerve (GON) infiltration approach in the management of occipital neuralgia (ON). Local IRB approval was obtained and written informed consent was waived. Thirty three patients suffering from severe refractory ON who underwent a total of 37 CT-guided GON infiltrations were included between 2012 and 2014. GON infiltration was performed at the first bend of the GON, between the inferior obliqus capitis and semispinalis capitis muscles with local anaesthetics and cortivazol. Pain was evaluated via VAS scores. Clinical success was defined by pain relief greater than or equal to 50 % lasting for at least 3 months. The pre-procedure mean pain score was 8/10. Patients suffered from left GON neuralgia in 13 cases, right GON neuralgia in 16 cases and bilateral GON neuralgia in 4 cases. The clinical success rate was 86 %. In case of clinical success, the mean pain relief duration following the procedure was 9.16 months. Simplified CT-guided infiltration appears to be effective in managing refractory ON. With this technique, infiltration of the GON appears to be faster, technically easier and, therefore, safer compared with other previously described techniques. • Occipital neuralgia is a very painful and debilitating condition • GON infiltrations have been successful in the treatment of occipital neuralgia • This simplified technique presents a high efficacy rate with long-lasting pain relief • This infiltration technique does not require contrast media injection for pre-planning • GON infiltration at the first bend appears easier and safer.

  4. Human occipital cortices differentially exert saccadic suppression: intracranial recording in children

    Science.gov (United States)

    Uematsu, Mitsugu; Matsuzaki, Naoyuki; Brown, Erik C.; Kojima, Katsuaki; Asano, Eishi

    2013-01-01

    By repeating saccades unconsciously, humans explore the surrounding world every day. Saccades inevitably move external visual images across the retina at high velocity; nonetheless, healthy humans don’t perceive transient blurring of the visual scene during saccades. This perceptual stability is referred to as saccadic suppression. Functional suppression is believed to take place transiently in the visual systems, but it remains unknown how commonly or differentially the human occipital lobe activities are suppressed at the large-scale cortical network level. We determined the spatial-temporal dynamics of intracranially-recorded gamma activity at 80–150 Hz around spontaneous saccades under no-task conditions during wakefulness and those in darkness during REM sleep. Regardless of wakefulness or REM sleep, a small degree of attenuation of gamma activity was noted in the occipital regions during saccades, most extensively in the polar and least in the medial portions. Longer saccades were associated with more intense gamma-attenuation. Gamma-attenuation was subsequently followed by gamma-augmentation most extensively involving the medial and least involving the polar occipital region. Such gamma-augmentation was more intense during wakefulness and temporally locked to the offset of saccades. The polarities of initial peaks of perisaccadic event-related potentials (ERPs) were frequently positive in the medial and negative in the polar occipital regions. The present study, for the first time, provided the electrophysiological evidence that human occipital cortices differentially exert peri-saccadic modulation. Transiently suppressed sensitivity of the primary visual cortex in the polar region may be an important neural basis for saccadic suppression. Presence of occipital gamma-attenuation even during REM sleep suggests that saccadic suppression might be exerted even without external visual inputs. The primary visual cortex in the medial region, compared to the

  5. prenatal ultrasound diagnosis of discordant occipital encephalocele

    African Journals Online (AJOL)

    drclement

    PRENATAL ULTRASOUND DIAGNOSIS OF DISCORDANT OCCIPITAL. ENCEPHALOCELE IN MULTIPLE PREGNANCY - A CASE REPORT. *O.U Ogbeide (MBBS, FMCR), *EJ IKUBOR (MBBS). *Department of Radiology University of Benin Teaching Hospital, Benin-City, Nigeria. Correspondence: Dr Ogbeide Osesogie ...

  6. Distorted images of one's own body activates the prefrontal cortex and limbic/paralimbic system in young women: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Kurosaki, Mitsuhaya; Shirao, Naoko; Yamashita, Hidehisa; Okamoto, Yasumasa; Yamawaki, Shigeto

    2006-02-15

    Our aim was to study the gender differences in brain activation upon viewing visual stimuli of distorted images of one's own body. We performed functional magnetic resonance imaging on 11 healthy young men and 11 healthy young women using the "body image tasks" which consisted of fat, real, and thin shapes of the subject's own body. Comparison of the brain activation upon performing the fat-image task versus real-image task showed significant activation of the bilateral prefrontal cortex and left parahippocampal area including the amygdala in the women, and significant activation of the right occipital lobe including the primary and secondary visual cortices in the men. Comparison of brain activation upon performing the thin-image task versus real-image task showed significant activation of the left prefrontal cortex, left limbic area including the cingulate gyrus and paralimbic area including the insula in women, and significant activation of the occipital lobe including the left primary and secondary visual cortices in men. These results suggest that women tend to perceive distorted images of their own bodies by complex cognitive processing of emotion, whereas men tend to perceive distorted images of their own bodies by object visual processing and spatial visual processing.

  7. Occipital cortical proton MRS at 4 Tesla in human moderate MDMA polydrug users

    OpenAIRE

    Cowan, Ronald L.; Bolo, Nicolas R.; Dietrich, Mary; Haga, Erica; Lukas, Scott E.; Renshaw, Perry F.

    2007-01-01

    The recreational drug MDMA (3,4, methylenedioxymethamphetamine; sold under the street name of Ecstasy) is toxic to serotonergic axons in some animal models of MDMA administration. In humans, MDMA use is associated with alterations in markers of brain function that are pronounced in occipital cortex. Among neuroimaging methods, magnetic resonance spectroscopy (MRS) studies of brain metabolites N-acetylaspartate (NAA) and myoinositol (MI) at a field strength of 1.5 Tesla (T) reveal inconsistent...

  8. Emotional face expression modulates occipital-frontal effective connectivity during memory formation in a bottom-up fashion

    Directory of Open Access Journals (Sweden)

    Daiming eXiu

    2015-04-01

    Full Text Available This study investigated the role of bottom-up and top-down neural mechanisms in the processing of emotional face expression during memory formation. Functional brain imaging data was acquired during incidental learning of positive (‘happy’, neutral and negative (‘angry’ or ‘fearful’ faces. Dynamic Causal Modeling (DCM was applied on the fMRI data to characterize effective connectivity within a brain network involving face perception (inferior occipital gyrus and fusiform gyrus and successful memory formation related areas (hippocampus, superior parietal lobule, amygdala and orbitofrontal cortex. The bottom-up models assumed processing of emotional face expression along feed forward pathways to the orbitofrontal cortex. The top-down models assumed that the orbitofrontal cortex processed emotional valence and mediated connections to the hippocampus. A subsequent recognition memory test showed an effect of negative emotion on the response bias, but not on memory performance. Our DCM findings showed that the bottom-up model family of effective connectivity best explained the data across all subjects and specified that emotion affected most bottom-up connections to the orbitofrontal cortex, especially from the occipital visual cortex and superior parietal lobule. Of those pathways to the orbitofrontal cortex the connection from the inferior occipital gyrus correlated with memory performance independently of valence. We suggest that bottom-up neural mechanisms support effects of emotional face expression and memory formation in a parallel and partially overlapping fashion.

  9. Benign occipital unicameral bone cyst causing lower cranial nerve palsies complicated by iophendylate arachnoiditis

    Science.gov (United States)

    Bradley, W. G.; Kalbag, R. M.; Ramani, P. S.; Tomlinson, B. E.

    1974-01-01

    A 20 year old girl presented with a history of neck and occipital pain for six weeks, which was found to be due to a unicameral bone cyst of the left occipital condylar region. The differential diagnosis of bone cysts in the skull is discussed. Six months after the operation, the patient again presented with backache due to adhesive arachnoiditis. The latter was believed to have arisen as a result of a combination of spinal infective meningitis and intrathecal ethyl iodophenyl undecylate (iophendylate, Myodil, Pantopaque). The nature of meningeal reactions to iophendylate and the part played by intrathecal corticosteroids in relieving the arachnoiditis in the present case are discussed. Images

  10. Efficient visual object and word recognition relies on high spatial frequency coding in the left posterior fusiform gyrus: evidence from a case-series of patients with ventral occipito-temporal cortex damage.

    Science.gov (United States)

    Roberts, Daniel J; Woollams, Anna M; Kim, Esther; Beeson, Pelagie M; Rapcsak, Steven Z; Lambon Ralph, Matthew A

    2013-11-01

    Recent visual neuroscience investigations suggest that ventral occipito-temporal cortex is retinotopically organized, with high acuity foveal input projecting primarily to the posterior fusiform gyrus (pFG), making this region crucial for coding high spatial frequency information. Because high spatial frequencies are critical for fine-grained visual discrimination, we hypothesized that damage to the left pFG should have an adverse effect not only on efficient reading, as observed in pure alexia, but also on the processing of complex non-orthographic visual stimuli. Consistent with this hypothesis, we obtained evidence that a large case series (n = 20) of patients with lesions centered on left pFG: 1) Exhibited reduced sensitivity to high spatial frequencies; 2) demonstrated prolonged response latencies both in reading (pure alexia) and object naming; and 3) were especially sensitive to visual complexity and similarity when discriminating between novel visual patterns. These results suggest that the patients' dual reading and non-orthographic recognition impairments have a common underlying mechanism and reflect the loss of high spatial frequency visual information normally coded in the left pFG.

  11. DCDC2 polymorphism is associated with left temporoparietal gray and white matter structures during development.

    Science.gov (United States)

    Darki, Fahimeh; Peyrard-Janvid, Myriam; Matsson, Hans; Kere, Juha; Klingberg, Torkel

    2014-10-22

    Three genes, DYX1C1, DCDC2, and KIAA0319, have been previously associated with dyslexia, neuronal migration, and ciliary function. Three polymorphisms within these genes, rs3743204 (DYX1C1), rs793842 (DCDC2), and rs6935076 (KIAA0319) have also been linked to normal variability of left temporoparietal white matter volume connecting the middle temporal cortex to the angular and supramarginal gyri. Here, we assessed whether these polymorphisms are also related to the cortical thickness of the associated regions during childhood development using a longitudinal dataset of 76 randomly selected children and young adults who were scanned up to three times each, 2 years apart. rs793842 in DCDC2 was significantly associated with the thickness of left angular and supramarginal gyri as well as the left lateral occipital cortex. The cortex was significantly thicker for T-allele carriers, who also had lower white matter volume and lower reading comprehension scores. There was a negative correlation between white matter volume and cortical thickness, but only white matter volume predicted reading comprehension 2 years after scanning. These results show how normal variability in reading comprehension is related to gene, white matter volume, and cortical thickness in the inferior parietal lobe. Possibly, the variability of gray and white matter structures could both be related to the role of DCDC2 in ciliary function, which affects both neuronal migration and axonal outgrowth. Copyright © 2014 the authors 0270-6474/14/3414455-08$15.00/0.

  12. Changes in regional cerebral blood flow in the right cortex homologous to left language areas are directly affected by left hemispheric damage in aphasic stroke patients: evaluation by Tc-ECD SPECT and novel analytic software.

    Science.gov (United States)

    Uruma, G; Kakuda, W; Abo, M

    2010-03-01

    The objective of this study was to clarify the influence of regional cerebral blood flow (rCBF) changes in language-relevant areas of the dominant hemisphere on rCBF in each region in the non-dominant hemisphere in post-stroke aphasic patients. The study subjects were 27 aphasic patients who suffered their first symptomatic stroke in the left hemisphere. In each subject, we measured rCBF by means of 99mTc-ethylcysteinate dimmer single photon emission computed tomography (SPECT). The SPECT images were analyzed by the statistical imaging analysis programs easy Z-score Imaging System (eZIS) and voxel-based stereotactic extraction estimation (vbSEE). Segmented into Brodmann Area (BA) levels, Regions of Interest (ROIs) were set in language-relevant areas bilaterally, and changes in the relative rCBF as average negative and positive Z-values were computed fully automatically. To assess the relationship between rCBF changes of each ROIs in the left and right hemispheres, the Spearman ranked correlation analysis and stepwise multiple regression analysis were applied. Globally, a negative and asymmetric influence of rCBF changes in the language-relevant areas of the dominant hemisphere on the right hemisphere was found. The rCBF decrease in left BA22 significantly influenced the rCBF increase in right BA39, BA40, BA44 and BA45. The results suggested that the chronic increase in rCBF in the right language-relevant areas is due at least in part to reduction in the trancallosal inhibitory activity of the language-dominant left hemisphere caused by the stroke lesion itself and that these relationships are not always symmetric.

  13. Occipital Nerve Stimulation for the Treatment of Refractory Occipital Neuralgia: A Case Series.

    Science.gov (United States)

    Keifer, Orion P; Diaz, Ashley; Campbell, Melissa; Bezchlibnyk, Yarema B; Boulis, Nicholas M

    2017-09-01

    Occipital neuralgia is a chronic pain syndrome characterized by sharp, shooting pains in the distribution of the occipital nerves. Although relatively rare, it associated with extremely debilitating symptoms that drastically affect a patient's quality of life. Furthermore, it is extremely difficult to treat as the symptoms are refractory to traditional treatments, including pharmacologic and procedural interventions. A few previous case studies have established the use of a neurostimulation of the occipital nerves to treat occipital neuralgia. The following expands on that literature by retrospectively reviewing the results of occipital nerve stimulation in a relatively large patient cohort (29 patients). A retrospective review of 29 patients undergoing occipital nerve stimulation for occipital neuralgia from 2012 to 2017 at a single institution with a single neurosurgeon. Of those 29 patients, 5 were repair or replacement of previous systems, 4 did not have benefit from trial stimulation, and 20 saw benefit to their trial stage of stimulation and went on to full implantation. Of those 20 patients, even with a history of failed procedures and pharmacological therapies, there was an overall success rate of 85%. The average preoperative 10-point pain score dropped from 7.4 ± 1.7 to a postoperative score of 2.9 ± 1.7. However, as with any peripheral nerve stimulation procedure, there were complications (4 patients), including infection, hardware erosion, loss of effect, and lead migration, which required revision or system removal. Despite complications, the results suggest, overall, that occipital nerve stimulation is a safe and effective procedure for refractory occipital neuralgia and should be in the neurosurgical repertoire for occipital neuralgia treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Ultrasound-Guided Greater Occipital Nerve Blocks and Pulsed Radiofrequency Ablation for Diagnosis and Treatment of Occipital Neuralgia

    OpenAIRE

    VanderHoek, Matthew David; Hoang, Hieu T; Goff, Brandon

    2013-01-01

    Occipital neuralgia is a condition manifested by chronic occipital headaches and is thought to be caused by irritation or trauma to the greater occipital nerve (GON). Treatment for occipital neuralgia includes medications, nerve blocks, and pulsed radiofrequency ablation (PRFA). Landmark-guided GON blocks are the mainstay in both the diagnosis and treatment of occipital neuralgia. Ultrasound is being utilized more and more in the chronic pain clinic to guide needle advancement when performing...

  15. Cortical disconnection of the ipsilesional primary motor cortex is associated with gait speed and upper extremity motor impairment in chronic left hemispheric stroke.

    Science.gov (United States)

    Peters, Denise M; Fridriksson, Julius; Stewart, Jill C; Richardson, Jessica D; Rorden, Chris; Bonilha, Leonardo; Middleton, Addie; Gleichgerrcht, Ezequiel; Fritz, Stacy L

    2018-01-01

    Advances in neuroimaging have enabled the mapping of white matter connections across the entire brain, allowing for a more thorough examination of the extent of white matter disconnection after stroke. To assess how cortical disconnection contributes to motor impairments, we examined the relationship between structural brain connectivity and upper and lower extremity motor function in individuals with chronic stroke. Forty-three participants [mean age: 59.7 (±11.2) years; time poststroke: 64.4 (±58.8) months] underwent clinical motor assessments and MRI scanning. Nonparametric correlation analyses were performed to examine the relationship between structural connectivity amid a subsection of the motor network and upper/lower extremity motor function. Standard multiple linear regression analyses were performed to examine the relationship between cortical necrosis and disconnection of three main cortical areas of motor control [primary motor cortex (M1), premotor cortex (PMC), and supplementary motor area (SMA)] and motor function. Anatomical connectivity between ipsilesional M1/SMA and the (1) cerebral peduncle, (2) thalamus, and (3) red nucleus were significantly correlated with upper and lower extremity motor performance (P ≤ 0.003). M1-M1 interhemispheric connectivity was also significantly correlated with gross manual dexterity of the affected upper extremity (P = 0.001). Regression models with M1 lesion load and M1 disconnection (adjusted for time poststroke) explained a significant amount of variance in upper extremity motor performance (R 2  = 0.36-0.46) and gait speed (R 2  = 0.46), with M1 disconnection an independent predictor of motor performance. Cortical disconnection, especially of ipsilesional M1, could significantly contribute to variability seen in locomotor and upper extremity motor function and recovery in chronic stroke. Hum Brain Mapp 39:120-132, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  16. Pure alexia after right temporo-occipital hemorrhage in a right-handed female

    Directory of Open Access Journals (Sweden)

    Buse Rahime Hasırcı

    2016-12-01

    Full Text Available Alexia without agraphia is a rare clinical disorder which is characterized by impairment of reading in spite of protection of writing ability. It usually results from infarction within the vascular territory of the posterior cerebral artery. The lesions of left occipital lobe or splenium of corpus callosum can cause alexia without agraphia by the deterioration of connection between the right occipital lobe and left parietal lobe. We describe the case of a 70-year-old right-handed woman who was presented with moderate headache and blurred vision and affected by alexia without agraphia and aphasia. Our case indicates that pure alexia may arise as a consequence of damage to the right hemisphere in right-handed patients and may lead to a severe reading disorder, as in individuals with left-hemisphere dominance for language.

  17. The temporal dynamics of implicit processing of non-letter, letter, and word-forms in the human visual cortex

    Directory of Open Access Journals (Sweden)

    Lawrence Gregory Appelbaum

    2009-11-01

    Full Text Available The decoding of visually presented line segments into letters, and letters into words, is critical to fluent reading abilities. Here we investigate the temporal dynamics of visual orthographic processes, focusing specifically on right hemisphere contributions and interactions between the hemispheres involved in the implicit processing of visually presented words, consonants, false fonts, and symbolic strings. High-density EEG was recorded while participants detected infrequent, simple, perceptual targets (dot strings embedded amongst a of character strings. Beginning at 130ms, orthographic and non-orthographic stimuli were distinguished by a sequence of ERP effects over occipital recording sites. These early latency occipital effects were dominated by enhanced right-sided negative-polarity activation for non-orthographic stimuli that peaked at around 180ms. This right-sided effect was followed by bilateral positive occipital activity for false-fonts, but not symbol strings. Moreover the size of components of this later positive occipital wave was inversely correlated with the right-sided ROcc180 wave, suggesting that subjects who had larger early right-sided activation for non-orthographic stimuli had less need for more extended bilateral (e.g. interhemispheric processing of those stimuli shortly later. Additional early (130-150ms negative-polarity activity over left occipital cortex and longer-latency centrally distributed responses (>300ms were present, likely reflecting implicit activation of the previously reported ‘visual-word-form’ area and N400-related responses, respectively. Collectively, these results provide a close look at some relatively unexplored portions of the temporal flow of information processing in the brain related to the implicit processing of potentially linguistic information and provide valuable information about the interactions between hemispheres supporting visual orthographic processing.

  18. Primary Occipital Encephalocele in an Elderly Patient.

    Science.gov (United States)

    Barros, Fernanda Carvalho; Barros, Henrique Almeida; Júnior, Helvécio Marangon; Taitson, Paulo Franco

    2016-05-01

    The encephalocele is a condition characterized by the protrusion of the intracranial contents through a bone defect of the skull. The authors report a clinical case of an 80-year-old woman with primary occipital encephalocele on the right side and that was affected by trauma and presented liquor fistula and infection. Tomographic sections were obtained by injection intravenous of contrast. The images showed bone thickness thinning on the right occipital region and solution of continuity (encephalocele) with regular contours, reduction in brain volume, and hypodensity of the periventricular white substance were observed. The patient was successfully operated.

  19. Headache Following Occipital Brain Lesion: A Case of Migraine Triggered by Occipital Spikes?

    Science.gov (United States)

    Vollono, Catello; Mariotti, Paolo; Losurdo, Anna; Giannantoni, Nadia Mariagrazia; Mazzucchi, Edoardo; Valentini, Piero; De Rose, Paola; Della Marca, Giacomo

    2015-10-01

    This study describes the case of an 8-year-old boy who developed a genuine migraine after the surgical excision, from the right occipital lobe, of brain abscesses due to selective infestation of the cerebrum by Entamoeba histolytica. After the surgical treatment, the boy presented daily headaches with typical migraine features, including right-side parieto-temporal pain, nausea, vomiting, and photophobia. Electroencephalography (EEG) showed epileptiform discharges in the right occipital lobe, although he never presented seizures. Clinical and neurophysiological observations were performed, including video-EEG and polygraphic recordings. EEG showed "interictal" epileptiform discharges in the right occipital lobe. A prolonged video-EEG recording performed before, during, and after an acute attack ruled out ictal or postictal migraine. In this boy, an occipital lesion caused occipital epileptiform EEG discharges without seizures, probably prevented by the treatment. We speculate that occipital spikes, in turn, could have caused a chronic headache with features of migraine without aura. Occipital epileptiform discharges, even in absence of seizures, may trigger a genuine migraine, probably by means of either the trigeminovascular or brainstem system. © EEG and Clinical Neuroscience Society (ECNS) 2014.

  20. Occipital and occipital "plus" epilepsies: A study of involved epileptogenic networks through SEEG quantification.

    Science.gov (United States)

    Marchi, Angela; Bonini, Francesca; Lagarde, Stanislas; McGonigal, Aileen; Gavaret, Martine; Scavarda, Didier; Carron, Romain; Aubert, Sandrine; Villeneuve, Nathalie; Médina Villalon, Samuel; Bénar, Christian; Trebuchon, Agnes; Bartolomei, Fabrice

    2016-09-01

    Compared with temporal or frontal lobe epilepsies, the occipital lobe epilepsies (OLE) remain poorly characterized. In this study, we aimed at classifying the ictal networks involving OLE and investigated clinical features of the OLE network subtypes. We studied 194 seizures from 29 consecutive patients presenting with OLE and investigated by stereoelectroencephalography (SEEG). Epileptogenicity of occipital and extraoccipital regions was quantified according to the 'epileptogenicity index' (EI) method. We found that 79% of patients showed widespread epileptogenic zone organization, involving parietal or temporal regions in addition to the occipital lobe. Two main groups of epileptogenic zone organization within occipital lobe seizures were identified: a pure occipital group and an occipital "plus" group, the latter including two further subgroups, occipitotemporal and occipitoparietal. In 29% of patients, the epileptogenic zone was found to have a bilateral organization. The most epileptogenic structure was the fusiform gyrus (mean EI: 0.53). Surgery was proposed in 18/29 patients, leading to seizure freedom in 55% (Engel Class I). Results suggest that, in patient candidates for surgery, the majority of cases are characterized by complex organization of the EZ, corresponding to the occipital plus group. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Tomonori Kagawa

    Full Text Available A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS. Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7, extrastriate cortex (BA18, BA19, and striate cortex (BA17 activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7, extrastriate cortex (BA18, 19, and striate cortex (BA17, as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

  2. Gastaut type idiopathic childhood occipital epilepsy.

    Science.gov (United States)

    Ferrari-Marinho, Taissa; Macedo, Eugenia Fialho; Costa Neves, Rafael Scarpa; Costa, Lívia Vianez; Tudesco, Ivanda S S; Carvalho, Kelly C; Carrete, Henrique; Caboclo, Luis Otavio; Yacubian, Elza Marcia; Hamad, Ana Paula

    2013-03-01

    Gastaut type idiopathic childhood occipital epilepsy is an uncommon epileptic syndrome characterised by frequent seizures, most commonly presenting as elementary visual hallucinations or blindness. Other occipital (non-visual) symptoms may also occur. Interictal EEG typically shows occipital paroxysms, often with fixation-off sensitivity. Ictal EEG is usually characterised by interruption by paroxysms and sudden appearance of low-voltage, occipital, fast rhythm and/or spikes. Despite well described clinical and EEG patterns, to our knowledge, there are very few reports in the literature with video-EEG recording of either seizure semiology or fixation-off phenomena. We present a video-EEG recording of a 12-year-old girl with Gastaut type epilepsy, illustrating the interictal and ictal aspects of this syndrome. Our aim was to demonstrate the clinical and neurophysiological pattern of a typical seizure of Gastaut type epilepsy, as well as the fixation-off phenomena, in order to further clarify the typical presentation of this syndrome. [Published with video sequences].

  3. Prognostic factors in patients with occipital encephalocele.

    Science.gov (United States)

    Kiymaz, Nejmi; Yilmaz, Nebi; Demir, Ismail; Keskin, Siddik

    2010-01-01

    An encephalocele is a herniation of the brain and the meninges through a skull defect protruding towards the exterior. The condition is not rare when compared to spinal dysraphisms, but the worldwide incidence is not precisely known. The cases involving occipital encephaloceles which we have diagnosed in our clinic and the surgical approaches for this rare condition are presented herein. Thirty patients who were diagnosed with occipital encephaloceles and referred to our Neurosurgery Clinic at the Yuzuncu Yil University, Faculty of Medicine Research Hospital between 2000 and 2009 were enrolled in this study. The age of the patient, size of the sac, pathologies that accompanied the condition, and treatments applied were assessed. In the present study, 30 patients (22 girls and 8 boys), whose ages varied between newborn and 14 months, were evaluated. The encephalocele sac was located in the occipital region in 27 patients (90%) and in the occipitocervical region in 3 patients (3%). Nine (30%) of the 30 patients died; 2 in the preoperative period, 2 in the postoperative early period (0-7 days) and 5 in the late postoperative period (first week to 3 months). With the exception of the 2 patients who died preoperatively, surgery was performed on all of the patients. The mortality rate in our study was 29%. Our study demonstrated that factors which determine the prognosis of patients diagnosed with occipital encephaloceles include the size of the sac, the contents of the neural tissue, hydrocephaly, infections, and pathologies that accompany the condition. An occipital encephalocele is a congenital neurologic condition with an extremely high morbidity and mortality in spite of the treatments rendered pre- and postoperatively. Copyright 2010 S. Karger AG, Basel.

  4. Neuralgias of the Head: Occipital Neuralgia.

    Science.gov (United States)

    Choi, Il; Jeon, Sang Ryong

    2016-04-01

    Occipital neuralgia is defined by the International Headache Society as paroxysmal shooting or stabbing pain in the dermatomes of the greater or lesser occipital nerve. Various treatment methods exist, from medical treatment to open surgical procedures. Local injection with corticosteroid can improve symptoms, though generally only temporarily. More invasive procedures can be considered for cases that do not respond adequately to medical therapies or repeated injections. Radiofrequency lesioning of the greater occipital nerve can relieve symptoms, but there is a tendency for the pain to recur during follow-up. There also remains a substantial group of intractable patients that do not benefit from local injections and conventional procedures. Moreover, treatment of occipital neuralgia is sometimes challenging. More invasive procedures, such as C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, neurectomy, and neurolysis with or without sectioning of the inferior oblique muscle, are now rarely performed for medically refractory patients. Recently, a few reports have described positive results following peripheral nerve stimulation of the greater or lesser occipital nerve. Although this procedure is less invasive, the significance of the results is hampered by the small sample size and the lack of long-term data. Clinicians should always remember that destructive procedures carry grave risks: once an anatomic structure is destroyed, it cannot be easily recovered, if at all, and with any destructive procedure there is always the risk of the development of painful neuroma or causalgia, conditions that may be even harder to control than the original complaint.

  5. Condroblastoma benigno do osso occipital: Relato do caso Benign chondroblastoma of the occipital bone: case report

    Directory of Open Access Journals (Sweden)

    João Flávio Mattos Araújo

    1995-12-01

    Full Text Available Condroblastoma benigno é tumor ósseo raro, tendo como origem células cartilagíneas. Classicamente este tumor acomete regiões epifisárias de ossos longos, sendo incomum o envolvimento de ossos do crânio, principalmente o osso occipital. Relatamos o caso de uma paciente com 16 anos de idade, com o diagnóstico de condroblastoma benigno do osso occipital e discutimos os principais aspectos deste tumor.Benign chondroblastoma is a rare bone tumor of immature cartilage cell derivation. This lesion classically occur at the ends of long bones in young persons. Chondroblastoma arising from the occipital bone is extremely rare. We report the case of a 16 year old girl with a benign condroblastoma in the occipital bone, and discuss the clinical, radiological and treatment aspects of this tumor.

  6. Hypoxic-Ischemic Encephalopathy With Clinical and Imaging Abnormalities Limited to Occipital Lobe.

    Science.gov (United States)

    Parmar, Hemant A; Trobe, Jonathan D

    2016-09-01

    The vulnerable brain areas in hypoxic-ischemic encephalopathy (HIE) following systemic hypotension are typically the neocortex, deep cerebral gray nuclei, hippocampus, cerebellum, and the parieto-occipital arterial border zone region. The visual cortex is not commonly recognized as a target in this setting. Single-institution review from 2007 to 2015 of patients who suffered cortical visual loss as an isolated clinical manifestation following systemic hypotension and whose brain imaging showed abnormalities limited to the occipital lobe. Nine patients met inclusion criteria. Visual loss at outset ranged from hand movements to 20/20, but all patients had homonymous field loss at best. In 1 patient, imaging was initially normal but 4 months later showed encephalomalacia. In 2 patients, imaging was initially subtle enough to be recognized as abnormal only when radiologists were advised that cortical visual loss was present. The occipital lobe may be an isolated target in HIE with cortical visual loss as the only clinical manifestation. Imaging performed in the acute period may appear normal or disclose abnormalities subtle enough to be overlooked. Radiologists informed of the clinical manifestations may be more attune to these abnormalities, which will become more apparent months later when occipital volume loss develops.

  7. Occipital cortical proton MRS at 4 Tesla in human moderate MDMA polydrug users.

    Science.gov (United States)

    Cowan, Ronald L; Bolo, Nicolas R; Dietrich, Mary; Haga, Erica; Lukas, Scott E; Renshaw, Perry F

    2007-08-15

    The recreational drug MDMA (3,4, methylenedioxymethamphetamine; sold under the street name of Ecstasy) is toxic to serotonergic axons in some animal models of MDMA administration. In humans, MDMA use is associated with alterations in markers of brain function that are pronounced in occipital cortex. Among neuroimaging methods, magnetic resonance spectroscopy (MRS) studies of brain metabolites N-acetylaspartate (NAA) and myoinositol (MI) at a field strength of 1.5 Tesla (T) reveal inconsistent results in MDMA users. Because higher field strength proton MRS has theoretical advantages over lower field strengths, we used proton MRS at 4.0 T to study absolute concentrations of occipital cortical NAA and MI in a cohort of moderate MDMA users (n=9) versus non-MDMA using (n=7) controls. Mean NAA in non-MDMA users was 10.47 mM (+/-2.51), versus 9.83 mM (+/-1.94) in MDMA users. Mean MI in non-MDMA users was 7.43 mM (+/-.68), versus 6.57 mM (+/-1.59) in MDMA users. There were no statistical differences in absolute metabolite levels for NAA and MI in occipital cortex of MDMA users and controls. These findings are not supportive of MDMA-induced alterations in NAA or MI levels in this small sample of moderate MDMA users. Limitations to this study suggest caution in the interpretation of these results.

  8. Occipital bone thickness: Implications on occipital-cervical fusion. A cadaveric study.

    Science.gov (United States)

    Zarghooni, Kourosh; Boese, Chrisoph K; Siewe, Jan; Röllinghoff, Marc; Eysel, Peer; Scheyerer, Max J

    2016-12-01

    The aim of this study was to create a map of the occipital bone using a cadaveric morphometric analysis. Twelve heads, from seven male and five female cadavers, were studied. The thickness of the occipital bone was measured with a digital vernier caliper within a coordinate system. The maximum thickness of the occipital bone could be measured at the external occipital protuberance (mean 15.4 mm; range 9-29.3 mm). All male individuals had higher bone thickness around this point. Further lateral a steady decrease of bone thickness could be observed. Same could be observed in craniocaudal direction. However, values above the superior nuchal line were on average thicker than below. The measurements demonstrated a great individual variability of bone thickness of the occipital bone. The results emphasize the role of preoperative planning for the feasibility of placement of an occipital screw. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  9. Analysis of the volumetric relationship among human ocular, orbital and fronto-occipital cortical morphology

    Science.gov (United States)

    Masters, Michael; Bruner, Emiliano; Queer, Sarah; Traynor, Sarah; Senjem, Jess

    2015-01-01

    Recent research on the visual system has focused on investigating the relationship among eye (ocular), orbital, and visual cortical anatomy in humans. This issue is relevant in evolutionary and medical fields. In terms of evolution, only in modern humans and Neandertals are the orbits positioned beneath the frontal lobes, with consequent structural constraints. In terms of medicine, such constraints can be associated with minor deformation of the eye, vision defects, and patterns of integration among these features, and in association with the frontal lobes, are important to consider in reconstructive surgery. Further study is therefore necessary to establish how these variables are related, and to what extent ocular size is associated with orbital and cerebral cortical volumes. Relationships among these anatomical components were investigated using magnetic resonance images from a large sample of 83 individuals, which also included each subject’s body height, age, sex, and uncorrected visual acuity score. Occipital and frontal gyri volumes were calculated using two different cortical parcellation tools in order to provide a better understanding of how the eye and orbit vary in relation to visual cortical gyri, and frontal cortical gyri which are not directly related to visual processing. Results indicated that ocular and orbital volumes were weakly correlated, and that eye volume explains only a small proportion of the variance in orbital volume. Ocular and orbital volumes were also found to be equally and, in most cases, more highly correlated with five frontal lobe gyri than with occipital lobe gyri associated with V1, V2, and V3 of the visual cortex. Additionally, after accounting for age and sex variation, the relationship between ocular and total visual cortical volume was no longer statistically significant, but remained significantly related to total frontal lobe volume. The relationship between orbital and visual cortical volumes remained significant for

  10. Analysis of the volumetric relationship among human ocular, orbital and fronto-occipital cortical morphology.

    Science.gov (United States)

    Masters, Michael; Bruner, Emiliano; Queer, Sarah; Traynor, Sarah; Senjem, Jess

    2015-10-01

    Recent research on the visual system has focused on investigating the relationship among eye (ocular), orbital, and visual cortical anatomy in humans. This issue is relevant in evolutionary and medical fields. In terms of evolution, only in modern humans and Neandertals are the orbits positioned beneath the frontal lobes, with consequent structural constraints. In terms of medicine, such constraints can be associated with minor deformation of the eye, vision defects, and patterns of integration among these features, and in association with the frontal lobes, are important to consider in reconstructive surgery. Further study is therefore necessary to establish how these variables are related, and to what extent ocular size is associated with orbital and cerebral cortical volumes. Relationships among these anatomical components were investigated using magnetic resonance images from a large sample of 83 individuals, which also included each subject's body height, age, sex, and uncorrected visual acuity score. Occipital and frontal gyri volumes were calculated using two different cortical parcellation tools in order to provide a better understanding of how the eye and orbit vary in relation to visual cortical gyri, and frontal cortical gyri which are not directly related to visual processing. Results indicated that ocular and orbital volumes were weakly correlated, and that eye volume explains only a small proportion of the variance in orbital volume. Ocular and orbital volumes were also found to be equally and, in most cases, more highly correlated with five frontal lobe gyri than with occipital lobe gyri associated with V1, V2, and V3 of the visual cortex. Additionally, after accounting for age and sex variation, the relationship between ocular and total visual cortical volume was no longer statistically significant, but remained significantly related to total frontal lobe volume. The relationship between orbital and visual cortical volumes remained significant for a

  11. Continuous theta-burst stimulation over the dorsal premotor cortex interferes with associative learning during object lifting.

    Science.gov (United States)

    Nowak, Dennis A; Berner, Julia; Herrnberger, Bärbel; Kammer, Thomas; Grön, Georg; Schönfeldt-Lecuona, Carlos

    2009-04-01

    When lifting objects of different mass, humans scale grip force according to the expected mass. In this context, humans are able to associate a sensory cue, such as a colour, to a particular mass of an object and link this association to the grip forces necessary for lifting. Here, we study the role of the dorsal premotor cortex (PMd) in setting-up an association between a colour cue and a particular mass to be lifted. Healthy right-handed subjects used a precision grip between the index finger and thumb to lift two different masses. Colour cues provided information about which of the two masses subjects would have to lift. Subjects first performed a series of lifts with the right hand to establish a stable association between a colour cue and a mass, followed by 20sec of continuous high frequency repetitive trancranial magnetic stimulation using a recently developed protocol (continuous theta-burst stimulation, cTBS) over (i) the left primary motor cortex, (ii) the left PMd and (iii) the left occipital cortex to be commenced by another series of lifts with either the right or left hand. cTBS over the PMd, but not over the primary motor cortex or O1, disrupted the predictive scaling of isometric finger forces based on colour cues, irrespective of whether the right or left hand performed the lifts after the stimulation. Our data highlight the role of the PMd to generalize and maintain associative memory processes relevant for predictive control of grip forces during object manipulation.

  12. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to study the anatomy of ...

  13. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Nancy Mohamed El Sekily

    2014-08-19

    Aug 19, 2014 ... Abstract Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to ...

  14. Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning.

    Science.gov (United States)

    Hampshire, Adam; Thompson, Russell; Duncan, John; Owen, Adrian M

    2011-01-01

    Reasoning is a key component of adaptable "executive" behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand-or the requirement to remap rules on to novel features-recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions.

  15. Lateral Prefrontal Cortex Subregions Make Dissociable Contributions during Fluid Reasoning

    Science.gov (United States)

    Thompson, Russell; Duncan, John; Owen, Adrian M.

    2011-01-01

    Reasoning is a key component of adaptable “executive” behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand—or the requirement to remap rules on to novel features—recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions. PMID:20483908

  16. Altered SPECT 123I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Science.gov (United States)

    Nagamitsu, Shinichiro; Sakurai, Rieko; Matsuoka, Michiko; Chiba, Hiromi; Ozono, Shuichi; Tanigawa, Hitoshi; Yamashita, Yushiro; Kaida, Hayato; Ishibashi, Masatoshi; Kakuma, Tatsuki; Croarkin, Paul E.; Matsuishi, Toyojiro

    2016-01-01

    Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using 123I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). “Depression–Dejection” and “Confusion” POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered

  17. The radiologic spectrum of occipital condyle fractures

    International Nuclear Information System (INIS)

    Hanson, J.A.; Deliganis, A.V.; Baxter, A.B.; Cohen, W.A.; Wilson, A.J.; Mann, F.A.

    2002-01-01

    Full text: Occipital condyle fractures (OCFs) are increasingly diagnosed in survivors of high energy blunt trauma, and may be associated with craniocervical junction disruption.We aimed to describe and classify the imaging appearances of occipital condyle fractures in a large series of trauma patients. We reviewed conventional radiographs, computed tomography (CT), and magnetic resonance (MR) imaging in 95 patients with 107 OCFs, who were treated at a level 1 trauma centre (1992-1999). We described fracture patterns according to two current classification systems (Anderson and Montesano, and Tuli), and correlated imaging appearances with clinical findings, neurosurgical management and patient outcome. Fracture morphology and craniocervical junction integrity were best assessed by 1-1.5mm collimation CT. Inferomedial occipital condyle avulsion fractures (Anderson and Montesano type III) were the commonest OCF category, comprising 80/107 (75%). Unilateral OCFs were found in 73/95 (77%) patients, 58 of whom were managed by cervical orthotic brace or collar. Bilateral OCFs or occipito-atlanto-axial joint injuries were seen in the remaining 22/95 (23%) patients. Occipitocervical fusion or craniocervical halo traction were required in 12 patients, all of whom had CT evidence of bilateral occipito-atlanto-axial joint disruption. Associated cervical spine injuries were present in 29/95 (31%) patients. Ten (10/95, 10.5%) patients died in hospital, and 30/95 (32%) showed continuing disability. The remaining 55/95 (57.5%) patients showed good outcome and functional independence at 1 month. Occipital condyle fractures are rare injuries with a wide range of morphology, stability and clinical significance. Thorough radiological evaluation of all components of the occipito-atlanto-axial joint complex must be performed in order to determine the full extent of injury. In this series, most unilateral OCFs were managed by non-operative immobilisation, whereas bilateral occipito

  18. Occipital pressure sores in two neonates.

    Science.gov (United States)

    Liu, Yi; Xiao, Bin; Zhang, Cheng; Su, Zhihong

    2015-01-01

    The preference for a specific head shape can be influenced by people's culture, religious beliefs and race. Modern Chinese people prefer a "talented" head shape, which is rounded and has a long profile. To obtain their preferred head shape, some parents try to change their neonates' sleeping position. Due to these forced sleeping positions, positional skull deformities, such as plagiocephaly, may be present during the first few months of life. In this article, we report two neonatal cases, of Hui nationality and Dongxiang nationality, with occipital pressure sores that were caused by using hard objects as pillows with the intention of obtaining a flattened occiput. The pressure sores were deep to the occipital bone and needed surgical management. These pressure sores caused wounds that were repaired by local skin flaps, after debridement, and the use of external constraints from a dense sponge-made head frame for approximately two weeks. One case recovered with primary healing after surgical operation. The other case suffered from a disruption of the sutured wound, and a secondary operation was performed to cover the wound. These occipital pressure sores are avoidable by providing guidance to the parents in ethnic minorities' area regarding the prevention, diagnosis and management of positional skull deformity.

  19. Bilateral optical nerve atrophy secondary to lateral occipital lobe infarction.

    Science.gov (United States)

    Mao, Junfeng; Wei, Shihui

    2013-06-01

    To report a phenomenon of optical nerve atrophy secondary to lateral occipital lobe infarction. Two successive patients with unilateral occipital lobe infarction who experienced bilateral optical nerve atrophy during the follow-up underwent cranial imaging, fundus photography, and campimetry. Each patient was diagnosed with occipital lobe infarction by cranial MRI. During the follow-up, a bilateral optic atrophy was revealed, and campimetry showed a right homonymous hemianopia of both eyes with concomitant macular division. Bilateral optic atrophy was related to occipital lobe infarction, and a possible explanation for the atrophy was transneuronal degeneration caused by occipital lobe infarction.

  20. Hypoplasia of the basi-occipital bone and persistance of the spheno-occipital synchondrosis in a patient with transitory supplementary fissure of the basi-occipital

    International Nuclear Information System (INIS)

    Wackenheim, A.

    1985-01-01

    The author had the opportunity to observe the progressive development of a special form of basilar impression characterized by transitory supplementary fissure of the basi-occipital bone, persistance of the spheno-occipital synchondrosis and hypoplasia of the basi-occipital. He proposes to dissociate the general concept of basilar impression and to consider anatomo-clinical entities such as the example described in this paper. (orig.)

  1. Relationship between cortical resection and visual function after occipital lobe epilepsy surgery.

    Science.gov (United States)

    Heo, Won; Kim, June Sic; Chung, Chun Kee; Lee, Sang Kun

    2017-10-27

    OBJECTIVE In this study, the authors investigated long-term clinical and visual outcomes of patients after occipital lobe epilepsy (OLE) surgery and analyzed the relationship between visual cortical resection and visual function after OLE surgery. METHODS A total of 42 consecutive patients who were diagnosed with OLE and underwent occipital lobe resection between June 1995 and November 2013 were included. Clinical, radiological, and histopathological data were reviewed retrospectively. Seizure outcomes were categorized according to the Engel classification. Visual function after surgery was assessed using the National Eye Institute Visual Functioning Questionnaire 25. The relationship between the resected area of the visual cortex and visual function was demonstrated by multivariate linear regression models. RESULTS After a mean follow-up period of 102.2 months, 27 (64.3%) patients were seizure free, and 6 (14.3%) patients had an Engel Class II outcome. Nineteen (57.6%) of 33 patients had a normal visual field or quadrantanopia after surgery (normal and quadrantanopia groups). Patients in the normal and quadrantanopia groups had better vision-related quality of life than those in the hemianopsia group. The resection of lateral occipital areas 1 and 2 of the occipital lobe was significantly associated with difficulties in general vision, peripheral vision, and vision-specific roles. In addition, the resection of intraparietal sulcus 3 or 4 was significantly associated with decreased social functioning. CONCLUSIONS The authors found a favorable seizure control rate (Engel Class I or II) of 78.6%, and 57.6% of the subjects had good visual function (normal vision or quadrantanopia) after OLE surgery. Lateral occipital cortical resection had a significant effect on visual function despite preservation of the visual field.

  2. Occipital Headaches in Children: Are They a Red Flag?

    Science.gov (United States)

    Genizi, Jacob; Khourieh-Matar, Amal; Assaf, Nurit; Chistyakov, Irena; Srugo, Isaac

    2017-10-01

    Occipital headache is considered a risk factor for serious secondary headache pathology. The purpose of our study was to assess the etiology of occipital headaches among children visiting the emergency department. Subjects were children aged 5 to 18 years who were referred to the emergency department due to headaches during the years 2013 to 2014. A total of 314 patients with headaches were seen at our emergency department. Thirty-nine patients had occipital headaches. Viral infections were the most prevalent final diagnosis (97; 31%), followed by migraine (37; 11.8%). None of our patients had a brain tumor. There was no difference in final diagnosis between the occipital and nonoccipital groups. The most common causes of occipital headaches are viral infections and primary headaches. Serious intracranial disorders presenting solely as occipital headaches and not accompanied by other neurologic signs are uncommon. Thus, occipital headaches should be evaluated in the same manner as other headache locations.

  3. Ruptured Aneurysms of the Occipital Artery Associated with Congenital Occipital Bone Defect.

    Science.gov (United States)

    Kawasaki, Toshinari; Yoshida, Kazumichi; Kikuchi, Takayuki; Ishii, Akira; Takagi, Yasushi; Miyamoto, Susumu

    2017-01-01

    Traumatic aneurysms of the superficial temporal artery have been frequently reported in the literature, whereas traumatic aneurysms of the occipital artery (OA) are extremely rare. A 30-year-old man had been followed at another hospital for meningoencephalocele associated with his congenital occipital bone defect. He was admitted to our hospital with a chief complaint of neck swelling and pain during a football game. Computed tomography and magnetic resonance imaging showed a hematoma in his right neck along with the meningoencephalocele. In addition, it showed an atrophic cerebellum with a cyst protruding from his occipital bone defect. Digital subtraction angiography of the right OA showed 3 aneurysms responsible for the large hematoma in his neck. Endovascular embolization with 20% N-butyl-2-cyanoacrylate was performed for treatment of the ruptured aneurysms followed by emergent surgical evacuation of the hematoma. An occipital cranioplasty with titanium mesh was performed 10 months after the emergent intervention. In this patient, the congenital occipital bone defect with meningoencephalocele might have been the remote source of risk for traumatic pseudoaneurysms along the muscle branches of the OA. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Laparoscopic adrenal cortex

    International Nuclear Information System (INIS)

    Peyrolou, A.; Salom, A.; Harguindeguy; Taroco, L.; Ardao, G.; Broli, F. . E mail: andresssss@adinet.com.uy

    2005-01-01

    The paper presents the case of a female patient who carried an aldosterone-secreting tumor of adrenal cortex.In the analysis of diagnosis and para clinical examinations there is particular reference to the laparoscopic surgery mode of treatment.Diagnosis should be established on the basis of clinical and laboratory tests (hypopotassemia and hyperaldosteronism).Tumor topography was confirmed through CT scan, MRI and Scintiscan in left adrenal cortex.Resection was consequently made through laparoscopic surgery.The patients evolution was excellent from the surgical viewpoint,with I levels of blood pressure, potassium and aldosterone returned to normal

  5. Frontal eye fields control attentional modulation of alpha and gamma oscillations in contralateral occipitoparietal cortex.

    Science.gov (United States)

    Marshall, Tom R; O'Shea, Jacinta; Jensen, Ole; Bergmann, Til O

    2015-01-28

    Covertly directing visuospatial attention produces a frequency-specific modulation of neuronal oscillations in occipital and parietal cortices: anticipatory alpha (8-12 Hz) power decreases contralateral and increases ipsilateral to attention, whereas stimulus-induced gamma (>40 Hz) power is boosted contralaterally and attenuated ipsilaterally. These modulations must be under top-down control; however, the control mechanisms are not yet fully understood. Here we investigated the causal contribution of the human frontal eye field (FEF) by combining repetitive transcranial magnetic stimulation (TMS) with subsequent magnetoencephalography. Following inhibitory theta burst stimulation to the left FEF, right FEF, or vertex, participants performed a visual discrimination task requiring covert attention to either visual hemifield. Both left and right FEF TMS caused marked attenuation of alpha modulation in the occipitoparietal cortex. Notably, alpha modulation was consistently reduced in the hemisphere contralateral to stimulation, leaving the ipsilateral hemisphere relatively unaffected. Additionally, right FEF TMS enhanced gamma modulation in left visual cortex. Behaviorally, TMS caused a relative slowing of response times to targets contralateral to stimulation during the early task period. Our results suggest that left and right FEF are causally involved in the attentional top-down control of anticipatory alpha power in the contralateral visual system, whereas a right-hemispheric dominance seems to exist for control of stimulus-induced gamma power. These findings contrast the assumption of primarily intrahemispheric connectivity between FEF and parietal cortex, emphasizing the relevance of interhemispheric interactions. The contralaterality of effects may result from a transient functional reorganization of the dorsal attention network after inhibition of either FEF. Copyright © 2015 the authors 0270-6474/15/351638-10$15.00/0.

  6. MRI study on the cortical thickness of occipital lobe in children with ametropic amblyopia

    International Nuclear Information System (INIS)

    Du Hanjian; Wang Jian; Li Chuan; Zhang Jiuquan; Chen Li; Liu Bo

    2008-01-01

    Objective: To study cortical thickness of the occipital lobe in children with ametropic amblyopia by using MRI technique and the FreeSurfer software. Methods: Nine children with ametropic amblyopia were included in the amblyopic group and 8 normal children were included in the control group. All the children underwent brain MRI on the Siemens Avanto 1.5 T scanner. For the cortical thickness analysis, 3-demensional MPRAGE images were collected and analyzed with FreeSurfer software package. Cortical thickness of related regions in the occipital lobe (including the cuneus, later occipital, lingual, and pericalcarine gyri) were recorded and compared. Results: The cortical thickness of the lingual, pericalcarine gyri on the left hemisphere and the cuneus, lateraloccipital, lingual gyri on the right hemisphere in amblyopic group were lower than the control group (P<0.05). Conclusion: Morphological changes existed in the occipital lobe in ametropic amblyopic children. The analysis technique with the FreeSurfer package has a potential value in the clinical application. (authors)

  7. A Technique for Resecting Occipital Pole Gliomas Using a Keyhole Lobectomy.

    Science.gov (United States)

    Conner, Andrew K; Baker, Cordell M; Briggs, Robert G; Burks, Joshua D; Glenn, Chad A; Smitherman, Adam D; Morgan, Jake P; Pittman, Nathan A; Sughrue, Michael E

    2017-10-01

    Our purpose is to describe a method of resecting occipital pole gliomas through a keyhole lobectomy and share the patient outcomes of this technique. We performed a retrospective review of data obtained on all patients who underwent resection of occipital pole gliomas by the senior author between 2012 and 2016. We describe our technique for resecting these tumors using a keyhole lobectomy and share the patient outcomes of this operation. Eight patients were included in this study. Four patients (50%) had not received previous surgery. One patient (13%) was diagnosed with a World Health Organization grade II tumor, and 7 patients (88%) were diagnosed with glioblastoma. Two tumors (25%) were left sided and 6 (75%) right sided. The median size of resection was 28 cm 3 . The median extent of resection was 96%, and at least 90% of the tumor was resected in all cases. None of the patients experienced permanent postoperative complications. Temporary neurologic complications included 3 patients (38%) with encephalopathy and 1 patient (13%) with aphasia. There were no neurosurgical complications. Our study provides details on the technical aspects of occipital keyhole lobectomies and gives the outcomes of patients who have received an operation for tumors in this uncommon location. Taking white matter tract anatomy into consideration, we show that the keyhole method can be applied to gliomas of the occipital lobe. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Dopamine release in human striatum induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex

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    Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2005-07-01

    Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25{+-}2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% {+-} 1.3% and 10.6% {+-} 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% {+-} 4.5% vs. 6.6% {+-} 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release.

  9. Dopamine release in human striatum induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex

    International Nuclear Information System (INIS)

    Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun

    2005-01-01

    Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25±2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% ± 1.3% and 10.6% ± 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% ± 4.5% vs. 6.6% ± 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release

  10. The Safe Area in the Parieto-Occipital Lobe in the Human Brain: Diffusion Tensor Tractography.

    Science.gov (United States)

    Jang, Sung Ho; Kim, Seong Ho; Kwon, Hyeok Gyu

    2015-06-01

    A recent study reported on the relatively safe area in the frontal lobe for performance of neurological interventions; however, no study on the posterior safe area has been reported. In this study, using diffusion tensor tractography, we attempted to identify the safe area in the parieto-occipital lobe in healthy subjects. A total of 47 healthy subjects were recruited for this study. Eleven neural tracts were reconstructed in and around the parieto-occipital area of the brain using diffusion tensor tractography. The safe area, which is free from any trajectory of 10 neural tracts, was measured anteriorly and medially from the line of the most posterior and lateral margin of the brain at 5 axial levels (from the cerebral cortex to the corona radiata). The anterior boundaries of the safe area in the upper cerebral cortex, lower cerebral cortex, centrum semiovale, upper corona radiata, and lower corona radiata levels were located at 31.0, 32.6, 32.7, 35.1, and 35.2 mm anteriorly from the line of the most posterior margin of the brain, respectively, and the medial boundaries were located at an average of 34.7, 38.1, 39.2, 36.1, and 33.6 mm medially from the line of the most lateral margin of the brain, respectively. According to our findings, the safe area was located in the posterolateral portion of the parieto-occipital lobe in the shape of a triangle. However, we found no safe area in the deep white matter around the lateral ventricle. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Widespread temporo-occipital lobe dysfunction in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Loewe, Kristian; Machts, Judith; Kaufmann, Jörn; Petri, Susanne; Heinze, Hans-Jochen; Borgelt, Christian; Harris, Joseph Allen; Vielhaber, Stefan; Schoenfeld, Mircea Ariel

    2017-01-09

    Recent studies suggest that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a single clinical continuum. However, previous neuroimaging studies have found only limited involvement of temporal lobe regions in ALS. To better delineate possible temporal lobe involvement in ALS, the present study aimed to examine changes in functional connectivity across the whole brain, particularly with regard to extra-motor regions, in a group of 64 non-demented ALS patients and 38 healthy controls. To assess between-group differences in connectivity, we computed edge-level statistics across subject-specific graphs derived from resting-state functional MRI data. In addition to expected ALS-related decreases in functional connectivity in motor-related areas, we observed extensive changes in connectivity across the temporo-occipital cortex. Although ALS patients with comorbid FTD were deliberately excluded from this study, the pattern of connectivity alterations closely resembles patterns of cerebral degeneration typically seen in FTD. This evidence for subclinical temporal dysfunction supports the idea of a common pathology in ALS and FTD.

  12. The occipital place area represents the local elements of scenes.

    Science.gov (United States)

    Kamps, Frederik S; Julian, Joshua B; Kubilius, Jonas; Kanwisher, Nancy; Dilks, Daniel D

    2016-05-15

    Neuroimaging studies have identified three scene-selective regions in human cortex: parahippocampal place area (PPA), retrosplenial complex (RSC), and occipital place area (OPA). However, precisely what scene information each region represents is not clear, especially for the least studied, more posterior OPA. Here we hypothesized that OPA represents local elements of scenes within two independent, yet complementary scene descriptors: spatial boundary (i.e., the layout of external surfaces) and scene content (e.g., internal objects). If OPA processes the local elements of spatial boundary information, then it should respond to these local elements (e.g., walls) themselves, regardless of their spatial arrangement. Indeed, we found that OPA, but not PPA or RSC, responded similarly to images of intact rooms and these same rooms in which the surfaces were fractured and rearranged, disrupting the spatial boundary. Next, if OPA represents the local elements of scene content information, then it should respond more when more such local elements (e.g., furniture) are present. Indeed, we found that OPA, but not PPA or RSC, responded more to multiple than single pieces of furniture. Taken together, these findings reveal that OPA analyzes local scene elements - both in spatial boundary and scene content representation - while PPA and RSC represent global scene properties. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Increased cortical thickness and altered functional connectivity of the right superior temporal gyrus in left-handers.

    Science.gov (United States)

    Li, Meiling; Chen, Heng; Wang, Junping; Liu, Feng; Wang, Yifeng; Lu, Fengmei; Yu, Chunshui; Chen, Huafu

    2015-01-01

    Altered structure in the temporal cortex has been implicated in the variable language laterality of left-handers (LH). The neuroanatomy of language lateralization and the corresponding synchronous functional connectivity (FC) in handedness cohorts are not, however, fully understood. We used structural and resting-state functional magnetic resonance imaging (fMRI) data to investigate the effect of altered cortical thickness on FC in LH and right-handers (RH). Whole-brain cortical thickness was calculated and compared between the LH and RH. We observed increased cortical thickness in the right superior temporal gyrus (STG) in the LH. A further FC analysis was conducted between the right STG and the remaining voxels in the brain. Compared with RH, the LH showed significantly higher FC in the left STG, right occipital cortex, and lower FC in the left inferior frontal gyrus and supramarginal gyrus. Our findings suggest that LH have atypical connectivity in the language network, with an enhanced role of the STG, findings which provide novel insights into the structural and functional substrates underlying the atypical language development of left-handed individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Hemispheric Dominance for Stereognosis in a Patient With an Infarct of the Left Postcentral Sensory Hand Area.

    Science.gov (United States)

    Moll, Jorge; de Oliveira-Souza, Ricardo

    2017-09-01

    The concept of left hemispheric dominance for praxis, speech, and language has been one of the pillars of neurology since the mid-19th century. In 1906, Hermann Oppenheim reported a patient with bilateral stereoagnosia (astereognosis) caused by a left parietal lobe tumor and proposed that the left hemisphere was also dominant for stereognosis. Surprisingly, few cases of bilateral stereoagnosia caused by a unilateral cerebral lesion have been documented in the literature since then. Here we report a 75-year-old right-handed man who developed bilateral stereoagnosia after suffering a small infarct in the crown of the left postcentral gyrus. He could not recognize objects with either hand, but retained the ability to localize stimuli applied to the palm of his left (ipsilesional) hand. He was severely disabled in ordinary activities requiring the use of his hands. The lesion corresponded to Brodmann area 1, where probabilistic anatomic, functional, and electrophysiologic studies have located one of the multiple somatosensory representations of the hand. The lesion was in a strategic position to interrupt both the processing of afferent tactile information issuing from the primary somatosensory cortex (areas 3a and 3b) and the forward higher-order processing in area 2, the secondary sensory cortex, and the contralateral area 1. The lesion also deprived the motor hand area of its afferent regulation from the sensory hand area (grasping), while leaving intact the visuomotor projections from the occipital cortex (reaching). Our patient supports Oppenheim's proposal that the left postcentral gyrus of some individuals is dominant for stereognosis.

  15. A RARE CASE OF ATYPICAL PRIMARY EWING’S SARCOMA OF OCCIPITAL BONE

    Directory of Open Access Journals (Sweden)

    K. Srihari

    2016-07-01

    Full Text Available BACKGROUND Ewing’s Sarcoma is an aggressive malignant neoplasm most frequently manifesting in the second decade of life and accounting for 4% of childhood and adolescent malignancies. These tumours were first described by James Ewing in 1921 as tumours that arise from bone. These osseous lesions have since become infamous for their highly aggressive course with 20% to 30% of patients having evidence of metastasis at the time of diagnosis and an estimated 10-year survival rate of 50%. Metastases to the CNS have most recently been estimated to occur in less than 5% of cases and are usually due to direct extension of an osseous lesion into the extradural space or more rarely through haematogenous spread. CASE REPORT In this article, we report a case of 17-year-old boy who presented to the radiology department with complaints of recurrent episodes of headache and vomiting for the past 3 days. On radiological investigation, there was a large well-defined, lobulated, extra-axial mass lesion measuring 3.6 X 5.7 X 5.9 cm noted in the supratentorial left occipital region which was fairly enhancing after contrast administration. The mass was causing permeative type of destruction of the left occipital bone and extending into extracranial soft tissue. Final diagnosis was done by biopsy and histopathology which showed “Atypical Ewing’s Sarcoma” of the left occipital bone. Considering its unusual site and soft tissue extension, we report this case of Primary Atypical Ewing’s sarcoma of occipital bone. CONCLUSION Primary cranial Ewing's sarcoma is to be considered in the differential diagnosis in children with a tumour involving the skull with destruction of the bone and presence of extra-axial soft tissue swelling. CT is the excellent modality for demonstration of bone destruction while MRI depicts soft tissue extension and metastasis if any.

  16. Parieto-occipital areas involved in efficient filtering in search: a time course analysis of visual marking using behavioural and functional imaging procedures

    DEFF Research Database (Denmark)

    Humphreys, Glyn W; Kyllingsbæk, Søren; Watson, Derrick G.

    2004-01-01

    (PET). We show that regions of parieto-occipital cortex are selectively activated in a preview search condition relative to a detection baseline. These regions also increase in activation as the preview interval increases (and search then becomes easier), consistent with them modulating the parallel...

  17. Application of Normative Occipital Condyle-C1 Interval Measurements to Detect Atlanto-Occipital Injury in Children.

    Science.gov (United States)

    Corcoran, B; Linscott, L L; Leach, J L; Vadivelu, S

    2016-05-01

    Prior studies have found that widening or asymmetry of the occipital condyle-C1 interval on CT is a sensitive and specific marker for atlanto-occipital dislocation. Previously reported abnormal occipital condyle-C1 interval values are not age-specific, possibly leading to false-positive findings in younger children, in whom this joint space is normally larger than that in adults. This study assesses the utility of applying age-specific normative occipital condyle-C1 interval ranges to documented cases of atlanto-occipital injury compared with previously reported abnormal cutoff values. Retrospective review of CT and MR imaging of 14 subjects with atlanto-occipital injury was performed, and occipital condyle-C1 interval measurements were made for each subject. Sensitivities and specificities of proposed occipital condyle-C1 interval cutoffs of 2 and 3 SDs above the mean and previously published occipital condyle-C1 interval cutoffs for atlanto-occipital injury were then calculated on the basis of occipital condyle-C1 interval measurements for each subject. An occipital condyle-C1 interval 2 SDs above the age-specific mean has a sensitivity of 50% and specificity of 89%-100%, depending on the age group. An occipital condyle-C1 interval 3 SDs above the age-specific mean has a sensitivity of 50% and a specificity of 95%-100%. A 4.0-mm occipital condyle-C1 interval has a sensitivity of 36% and a specificity of 100% in all age groups. A 2.5-mm occipital condyle-C1 interval has a sensitivity of 93% and a specificity of 18%-100%. Occipital condyle-C1 interval widening cutoffs used to establish atlanto-occipital injury lack both sensitivity and specificity in children and young teenagers. MR imaging is necessary to establish a diagnosis of atlanto-occipital injury in children and young teenagers when the appropriate mechanism of injury is present. © 2016 by American Journal of Neuroradiology.

  18. Unilateral Eye Blinking Arising From the Ictal Ipsilateral Occipital Area.

    Science.gov (United States)

    Falsaperla, Raffaele; Perciavalle, Valentina; Pavone, Piero; Praticò, Andrea Domenico; Elia, Maurizio; Ruggieri, Martino; Caraballo, Roberto; Striano, Pasquale

    2016-07-01

    We report on an 18-month-old boy with unilateral left eye blinking as a single ictal manifestation without facial twitching. The clinical onset of this phenomenon was first recorded (as an occasional event) at age 3 months, and it was overlooked. By age 6 months, the child's blinking increased to almost daily occurrence in clusters: during blinking the infant showed intact awareness and occasional jerks in the upper limbs and right leg. A video-electroencephalography (video-EEG) documented clinical correlation with a focal pattern arising from the left occipital region, and brain magnetic resonance imaging (MRI) revealed severe brain damage, consisting in poroencephalic hollows and increased spaces in the convexities involving a large area of the left cerebral hemisphere. The boy was prescribed sodium valproate (30 mg/kg/d), resulting in drastic reduction of his clinical seizures. Follow-up to his current age documented good general status, with persistent partial right hemilateral seizures. The blinking progressively disappeared, and is no longer recorded. The pathogenic hypotheses of the unilateral ictal blinking include involvement of the ipsilateral cerebral hemisphere and/or the cerebellar pathways. Review of previous reports of unilateral eye blinking, arising from the ictal ipsilateral brain, revealed that different damaged regions may give rise to blinking ictal phenomena, likely via the trigeminal fibres innervating the subdural intracranial structures and the pial vessels in the ipsilateral affected brain. The eye blinking in the present child represents a further example of an ictal phenomenon, which is predictive of the damaged brain region. © EEG and Clinical Neuroscience Society (ECNS) 2014.

  19. Auditory attention activates peripheral visual cortex.

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    Anthony D Cate

    Full Text Available BACKGROUND: Recent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency. CONCLUSIONS/SIGNIFICANCE: Auditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.

  20. Reorganization of retinotopic maps after occipital lobe infarction.

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    Vaina, Lucia M; Soloviev, Sergei; Calabro, Finnegan J; Buonanno, Ferdinando; Passingham, Richard; Cowey, Alan

    2014-06-01

    We studied patient JS, who had a right occipital infarct that encroached on visual areas V1, V2v, and VP. When tested psychophysically, he was very impaired at detecting the direction of motion in random dot displays where a variable proportion of dots moving in one direction (signal) were embedded in masking motion noise (noise dots). The impairment on this motion coherence task was especially marked when the display was presented to the upper left (affected) visual quadrant, contralateral to his lesion. However, with extensive training, by 11 months his threshold fell to the level of healthy participants. Training on the motion coherence task generalized to another motion task, the motion discontinuity task, on which he had to detect the presence of an edge that was defined by the difference in the direction of the coherently moving dots (signal) within the display. He was much better at this task at 8 than 3 months, and this improvement was associated with an increase in the activation of the human MT complex (hMT(+)) and in the kinetic occipital region as shown by repeated fMRI scans. We also used fMRI to perform retinotopic mapping at 3, 8, and 11 months after the infarct. We quantified the retinotopy and areal shifts by measuring the distances between the center of mass of functionally defined areas, computed in spherical surface-based coordinates. The functionally defined retinotopic areas V1, V2v, V2d, and VP were initially smaller in the lesioned right hemisphere, but they increased in size between 3 and 11 months. This change was not found in the normal, left hemisphere of the patient or in either hemispheres of the healthy control participants. We were interested in whether practice on the motion coherence task promoted the changes in the retinotopic maps. We compared the results for patient JS with those from another patient (PF) who had a comparable lesion but had not been given such practice. We found similar changes in the maps in the lesioned

  1. Temporal and occipital lobe features in children with hypochondroplasia/FGFR3 gene mutation.

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    Philpott, Cristina M; Widjaja, Elysa; Raybaud, Charles; Branson, Helen M; Kannu, Peter; Blaser, Susan

    2013-09-01

    Thanatophoric dysplasia (TD) and hypochondroplasia are both caused by FGFR3 (fibroblast growth factor receptor 3) gene mutations. Temporal lobe dysplasia has been well described in thanatophoric dysplasia; however, only a couple of anecdotal cases of temporal lobe dysplasia in hypochondroplasia have been described. To define temporal lobe abnormalities in patients with hypochondroplasia, given that they share the same genetic mutation. We identified brain imaging studies of nine children with hypochondroplasia. The temporal lobes were assessed on CT and MRI for size and configuration of the temporal horn and aberrant sulcation of the inferior surface of the temporal lobe. All children had a triangular-shape temporal horn and deep transverse fissures of the inferior temporal lobe surface. Neuroimaging in our cohort revealed enlarged temporal lobes and oversulcation of the mesial temporal and occipital lobes, with abnormal inferomedial orientation of these redundant gyri. Hippocampal dysplasia was also universal. We confirmed frequent inferomesial temporal and occipital lobe abnormalities in our cohort of children with hypochondroplasia. Murine models with mutant fgfr3 display increased neuroprogenitor proliferation, cortical thickness and surface area in the temporo-occipital cortex. This is thought to result in excessive convolution and likely explains the imaging findings in this patient cohort. (Note that fgfr3 is the same genetic mutation in mice as FGFR3 is in humans.).

  2. Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

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    Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min [Center for Biosignals, Korea Research Institute of Standards and Science(KRISS), Daejeon (Korea, Republic of)

    2015-12-15

    Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively.

  3. Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

    International Nuclear Information System (INIS)

    Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min

    2015-01-01

    Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively

  4. Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

    Science.gov (United States)

    Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

    2014-07-01

    Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors. Copyright © 2013 Wiley Periodicals, Inc.

  5. Altered SPECT 123I iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

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    Shinichiro eNagamitsu

    2016-02-01

    Full Text Available Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN in children. The purpose of this study was to examine cortical GABA(A-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single photon emission computed tomography (SPECT measurements using 123I iomazenil, which binds to GABA(A-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26 and the short form of the Profile of Mood States (POMS. Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil binding activity in cortical regions of interest (ROIs and psychometric profiles, and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil binding activity in the anterior posterior cingulate cortex (ACC. Higher POMS subscale scores were significantly associated with lower iomazenil binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC. Depression-Dejection, and Confusion POMS subscale scores, and total POMS score, showed interaction effects with brain regions in iomazenil binding activity. Decreased binding in the ACC and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered in children

  6. Morphological dissociation between visual pathways and cortex: MRI of visually-deprived patients with congenital peripheral blindness

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    Breitenseher, M.; Prayer Wimberger, D.; Trattnig, S.; Kramer, J. [MR-Institute of the Medical Faculty and Clinic for Diagnostic Radiology, University of Vienna (Austria); Uhl, F.; Deecke, L. [Department of Neurology, University of Vienna (Austria)

    1998-07-01

    MRI was used to study possible morphological changes in the visual system in 12 patients suffering from congenital blindness of peripheral (ocular) origin. While their optical pathways showed degeneration, hypoplasia or atrophy in 7 out of 12 cases, the occipital cortex appeared normal in all cases. This dissociation between afferent pathways and the cortex is contrary to the assumption that visually deprived cortex may undergo degeneration. The finding is congruent with evidence that the occipital cortex is used for other, nonvisual functions. (orig.) With 3 figs., 1 tab., 23 refs.

  7. True aneurysm of the proximal occipital artery: Case report

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    Giulio Illuminati

    Full Text Available Introduction: True aneurysms of the proximal occipital artery are rare, may cause neurological symptoms due to compression of the hypoglossal nerve and their resection may be technically demanding. Presentation of case: The case of an aneurysm of the proximal occipital artery causing discomfort and tongue deviation by compression on the hypoglossal nerve is reported. Postoperative course after resection was followed by complete regression of symptoms. Conclusion: Surgical resection, as standard treatment of aneurysms of the occipital artery, with the eventual technical adjunct of intubation by the nose is effective in durably relieving symptoms and preventing aneurysm-related complication. Keywords: Arterial aneurysm, Occipital artery, Case report

  8. Sex Prediction using Foramen Magnum and Occipital Condyles Computed Tomography Measurements in Sudanese Population

    Directory of Open Access Journals (Sweden)

    Usama Mohamed El-Barrany

    2016-12-01

    Full Text Available Sex determination is important in establishing the identity of an individual. The foramen magnum is an important landmark of the skull base. The present research aimed to study the value of foramen magnum measurements to determine sex using computed tomography (CT among Sudanese individuals. Foramen magnum CT scans of 400 Sudanese individuals (200 males and 200 females aged 18 - 83 years were included in this study. Foramen magnum (length and width, right occipital condyle (length and width, left occipital condyle (length and width, minimum intercondylar distance, maximum bicondylar distance and maximum medial intercondylar distance were measured. All data were subjected to discriminant functions analysis. All nine measurements were significantly higher in males than females. Among these measurements, the right condyle length, minimum intercondylar distance, and foramen magnum width were able to determine sex in Sudanese individuals with an accuracy rate of 83 %.

  9. Reduced frontal and occipital lobe asymmetry on the CT-scans of schizophrenic patients. Its specificity and clinical significance

    International Nuclear Information System (INIS)

    Falkai, P.; Schneider, T.; Greve, B.; Klieser, E.; Bogerts, B.

    1995-01-01

    Frontal and occipital lobe widths were determined in the computed tomographic (CT) scans of 135 schizophrenic patients, 158 neuro psychiatrically healthy and 102 psychiatric control subjects, including patients with affective psychosis, neurosis and schizoaffective psychosis. Most healthy right-handed subjects demonstrate a relative enlargement of the right frontal as well as left occipital lobe compared to the opposite hemisphere. These normal frontal and occipital lobe asymmetries were selectively reduced in schizophrenics (f.: 5%, p < .0005; o.: 3%, p < .05), irrespective of the pathophysiological subgroup. Schizophrenic neuroleptic non-responders revealed a significant reduction of frontal lobe asymmetry (3%, p < .05), while no correlation between BPRS-sub scores and disturbed cerebral laterality could be detected. In sum the present study demonstrates the disturbed cerebral lateralisation in schizophrenic patients supporting the hypothesis of interrupted early brain development in schizophrenia. (author)

  10. Solitary Langerhans cell histiocytosis of the occipital condyle: a case report and review of the literature.

    Science.gov (United States)

    Teranishi, Yu; Shin, Masahiro; Yoshino, Masanori; Saito, Nobuhito

    2016-02-01

    Despite the recent advent of various radiographic imaging techniques, it is still very difficult to correctly distinguish a pediatric osteolytic lesion in the occipital condyle, which makes it further complicated to decide on the necessity of and the adequate timing for radical resection and craniocervical fusions. To establish a legitimate therapeutic strategy for this deep-seated lesion, surgical biopsy is a reasonable choice for first-line intervention. The choice of surgical approach becomes very important because a sufficient amount of histological specimen must be obtained to confirm the diagnosis but, ideally, the residual bony structures and the muscular structures should be preserved so as not to increase craniocervical instability. In this report, we present our experience with a case of solitary Langerhans cell histiocytosis (LCH) involving the occipital condyle that was successfully treated with minimally invasive surgical biopsy with a far lateral condylar approach supported by preoperative 3D computer graphic simulation. An 8-year-old girl presented with neck pain. Magnetic resonance imaging and computed tomography (CT) revealed an osteolytic lesion of the left occipital condyle. At surgery, the patient was placed in the prone position. A 3-cm skin incision was made in the posterior auricular region, and the sternocleidomastoid and splenius capitis muscles were dissected in the middle of the muscle bundle along the direction of the muscle fiber. Under a navigation system, we approached the occipital condyle through the space between the longissimus capitis muscle and the posterior belly of the digastric muscle and lateral to the superior oblique muscle, verifying each muscle at each depth of the surgical field and, finally, obtained sufficient surgical specimen. After the biopsy, her craniocervical instability had not worsened, and chemotherapy was performed. Twelve weeks after chemotherapy, her neck pain had gradually disappeared along with her

  11. Lateralized occipital degeneration in posterior cortical atrophy predicts visual field deficits.

    Science.gov (United States)

    Millington, Rebecca S; James-Galton, Merle; Maia Da Silva, Mari N; Plant, Gordon T; Bridge, Holly

    2017-01-01

    Posterior cortical atrophy (PCA), the visual variant of Alzheimer's disease, leads to high-level visual deficits such as alexia or agnosia. Visual field deficits have also been identified, but often inconsistently reported. Little is known about the pattern of visual field deficits or the underlying cortical changes leading to this visual loss. Multi-modal magnetic resonance imaging was used to investigate differences in gray matter volume, cortical thickness, white matter microstructure and functional activity in patients with PCA compared to age-matched controls. Additional analyses investigated hemispheric asymmetries in these metrics according to the visual field most affected by the disease. Analysis of structural data indicated considerable loss of gray matter in the occipital and parietal cortices, lateralized to the hemisphere contralateral to the visual loss. This lateralized pattern of gray matter loss was also evident in the hippocampus and parahippocampal gyrus. Diffusion-weighted imaging showed considerable effects of PCA on white matter microstructure in the occipital cortex, and in the corpus callosum. The change in white matter was only lateralized in the occipital lobe, however, with greatest change in the optic radiation contralateral to the visual field deficit. Indeed, there was a significant correlation between the laterality of the optic radiation microstructure and visual field loss. Detailed brain imaging shows that the asymmetric visual field deficits in patients with PCA reflect the pattern of degeneration of both white and gray matter in the occipital lobe. Understanding the nature of both visual field deficits and the neurodegenerative brain changes in PCA may improve diagnosis and understanding of this disease.

  12. Occipital lobe seizures and subcortical T2 and T2* hypointensity associated with nonketotic hyperglycemia: a case report.

    Science.gov (United States)

    Sasaki, Fuyuko; Kawajiri, Sumihiro; Nakajima, Sho; Yamaguchi, Ai; Tomizawa, Yuji; Noda, Kazuyuki; Hattori, Nobutaka; Okuma, Yasuyuki

    2016-08-12

    Nonketotic hyperglycemia often causes seizures. Recently, seizures associated with nonketotic hyperglycemia have been found to be associated with subcortical T2 hypointensity on magnetic resonance imaging, especially in the occipital lobes. However, the mechanism remains unclear, although iron accumulation is suggested. We present a case of occipital lobe seizures associated with nonketotic hyperglycemia supporting the hypothesis that the mechanism of subcortical T2 hypointensity is iron accumulation using gradient-echo T2*-weighted magnetic resonance imaging. A 65-year-old Japanese man complained of intermittent pastel-colored flashing lights. On neurological examination, he also had lower right-side quadrant hemianopia. No other abnormal neurological findings were found. On laboratory analysis, his blood glucose level was 370 mg/dL, HbA1c was 11.4 %, and serum osmolarity was 326 mOsm/L. No ketones were detected in urine. A magnetic resonance imaging scan of his head showed subcortical T2 and T2* hypointensity in his left occipital lobe. Single-photon emission computed tomography with I123-N-isopropyl-iodoamphetamine revealed hyperperfusion in the left dominant occipital lobe. These magnetic resonance imaging abnormalities resolved during clinical recovery and treatment to control his blood sugar level. Therefore, a diagnosis of occipital lobe seizures associated with nonketotic hyperglycemia was made. To the best of our knowledge, this is the first case of occipital lobe seizures associated with nonketotic hyperglycemia supporting the role of iron accumulation as a mechanism for subcortical T2 hypointensity using T2*-magnetic resonance imaging.

  13. Remnants of occipital vertebrae: proatlas segmentation abnormalities.

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    Menezes, Arnold H; Fenoy, Kathleen A

    2009-05-01

    Developmental remnants around the foramen magnum, or proatlas segmentation abnormalities, have been recorded in postmortem studies but very rarely in a clinical setting. Because of their rarity, the pathological anatomy has been misunderstood, and treatment has been fraught with failures. The objectives of this prospective study were to understand the correlative anatomy, pathology, and embryology and to recognize the clinical presentation and gain insights on the treatment and management. Our craniovertebral junction (CVJ) database started in 1977 and comprises 5200 cases. This prospective study has retrieval capabilities. Neurodiagnostic studies changed with the evolution of imaging. Seventy-two patients were recognized as having symptomatic proatlas segmentation abnormalities. Ventral bony masses from the clivus or medial occipital condyle occurred in 66% (44/72), lateral or anterolateral compressive masses in 37% (27 of 72 patients), and dorsal bony compression in 17% (12 of 72 patients). Hindbrain herniation was associated in 33%. The age at presentation was 3 to 23 years. Motor symptoms occurred in 72% (52 of 72 patients); palsies in Cranial Nerves IX, X, and XII in 33% (24 of 72 patients); and vertebrobasilar symptoms in 25% (18 of 72 patients). Trauma precipitated symptoms in 55% (40 of 72 patients). The best definition of the abnormality was demonstrated by 3-dimensional computed tomography combined with magnetic resonance imaging. Treatment was aimed at decompression of the pathology and stabilization. Remnants of the occipital vertebrae around the foramen magnum were recognized in 72 of 5200 CVJ cases (7.2%). Magnetic resonance imaging with 3-dimensional computed tomography of the CVJ provides the best definition and understanding of the lesions. Brainstem myelopathy and lower cranial nerve deficits are common clinical presentations in the first and second decades of life. Treatment is aimed at decompression of the pathology and CVJ stabilization.

  14. Delayed Occipital Artery Pseudoaneurysm Following Blunt Force Trauma.

    Science.gov (United States)

    Changa, Abhinav R; Meleis, Ahmed M; Bassani, Luigi

    2016-05-01

    Occipital artery pseudoaneurysms are extremely rare pathologies that manifest after traumatic injury; only 11 cases have been reported in the literature. Because of their low incidence and vague symptoms, the initial diagnosis can be difficult. However, for correctly diagnosed occipital artery pseudoaneurysms, many successful treatment modalities exist. We review the pathology of occipital pseudoaneurysms, elucidate the reasons for their rarity, discuss effective diagnostic measures, and discuss the currently available treatment options. We also present a case of a 16-year-old boy who sustained blunt force trauma in May 2014 and presented 6 months later with a painful, pulsatile mass in the occipital region. The patient underwent surgical resection to alleviate the pain and the potential risk of hemorrhage. He experienced complete resolution of pain and associated symptoms. Our case highlights the fact that occipital swelling, a significant initial sign of pseudoaneurysm development, can be delayed. Therefore, occipital artery pseudoaneurysms cannot be ruled out of the differential diagnosis based on time course alone. Surgical resection is a quick and effective method for relief of severe pain resulting from occipital artery pseudoaneurysms. Although they are rare entities, occipital artery pseudoaneurysms must be considered in the differential diagnosis of cases of pulsatile mass lesions in the posterior scalp. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Explicit memory and implicit memory in occipital lobe stroke patients.

    Science.gov (United States)

    Gong, Liang; Wang, JiHua; Feng, Lei; Wang, MeiHong; Li, Xiu; Hu, JiaYun; Wang, Kai

    2015-03-01

    Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  16. Peripheral neurostimulation for control of intractable occipital neuralgia.

    Science.gov (United States)

    Weiner, R L; Reed, K L

    1999-07-01

    Objective. To present a novel approach for treatment of intractable occipital neuralgia using percutaneous peripheral nerve electrostimulation techniques. Methods. Thirteen patients underwent 17 implant procedures for medically refractory occipital neuralgia. A subcutaneous electrode placed transversely at the level of C1 across the base of the occipital nerve trunk produced paresthesias and pain relief covering the regions of occipital nerve pain Results. With follow-up ranging from 1-½ to 6 years, 12 patients continue to report good to excellent response with greater than 50% pain control and requiring little or no additional medications. The 13th patient (first in the series) was subsequently explanted following symptom resolution. Conclusions. In patients with medically intractable occipital neuralgia, peripheral nerve electrostimulation subcutaneously at the level of C1 appears to be a reasonable alternative to more invasive surgical procedures following failure of more conservative therapies.

  17. Reduced resting state functional connectivity of the somatosensory cortex predicts psychopathological symptoms in women with bulimia nervosa

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    Luca eLavagnino

    2014-08-01

    Full Text Available BackgroundAlterations in the resting state functional connectivity (rs-FC of several brain networks have been demonstrated in eating disorders. However, very few studies are currently available on brain network dysfunctions in bulimia nervosa (BN. The somatosensory network is central in processing body-related stimuli and it may be altered in BN. The present study therefore aimed to investigate rs-FC in the somatosensory network in bulimic women. MethodsSixteen medication-free women with BN (age=23±5 years and 18 matched controls (age=23±3 years underwent a functional magnetic resonance resting state scan and assessment of eating disorder symptoms. Within-network and seed-based functional connectivity analyses were conducted to assess rs-FC within the somatosensory network and to other areas of the brain. ResultsBN patients showed a decreased resting state functional connectivity both within the somatosensory network (t=9.0, df=1, P=0.005 and with posterior cingulate cortex (PCC and two visual areas (the right middle occipital gyrus and the right cuneus(P=0.05 corrected for multiple comparison. The region in the right middle occipital gyrus is implicated in body processing and is known as extrastriate body area, or EBA. The rs-FC of the left paracentral lobule with the EBA correlated with psychopathology measures like bulimia (r=-0.4; P=0.02 and interoceptive awareness (r=-0.4; P=0.01. Analyses were conducted using age, BMI (body mass index and depressive symptoms as covariates. ConclusionsOur findings show a specific alteration of the rs-FC of the somatosensory cortex in BN patients, which correlates with eating disorder symptoms. The connectivity between the somatosensory cortex and the EBA might be related to dysfunctions in body image processing. The results should be considered preliminary due to the small sample size.

  18. Internal Occipital Crest Misalignment with Internal Occipital Protuberance: A Case Report of Posterior Cranial Fossa Anatomic Variations

    Science.gov (United States)

    Kim, Jae Ha

    2016-01-01

    During gross anatomy head and neck laboratory session, one dissection group observed an abnormal anatomic variation in the posterior cranial fossa of a 94-year-old male cadaver. The internal occipital crest was not aligned with internal occipital protuberance and groove for superior sagittal sinus. It seemed that the internal occipital protuberance was shifted significantly to the right side. As a result the skull was overly stretched in order to connect with the internal occipital ridge. These internal skull variations of occipital bone landmarks can influence the location of adjacent dural venous sinuses and possibly influence cerebrospinal fluid flow. Similar anatomical anomalies have been attributed to presence of hydrocephalus and abnormalities in cisterna magna. PMID:27648322

  19. Context-specific differences in fronto-parieto-occipital effective connectivity during short-term memory maintenance.

    Science.gov (United States)

    Kundu, Bornali; Chang, Jui-Yang; Postle, Bradley R; Van Veen, Barry D

    2015-07-01

    Although visual short-term memory (VSTM) performance has been hypothesized to rely on two distinct mechanisms, capacity and filtering, the two have not been dissociated using network-level causality measures. Here, we hypothesized that behavioral tasks challenging capacity or distraction filtering would both engage a common network of areas, namely dorsolateral prefrontal cortex (dlPFC), superior parietal lobule (SPL), and occipital cortex, but would do so according to dissociable patterns of effective connectivity. We tested this by estimating directed connectivity between areas using conditional Granger causality (cGC). Consistent with our prediction, the results indicated that increasing mnemonic load (capacity) increased the top-down drive from dlPFC to SPL, and cGC in the alpha (8-14Hz) frequency range was a predominant component of this effect. The presence of distraction during encoding (filtering), in contrast, was associated with increased top-down drive from dlPFC to occipital cortices directly and from SPL to occipital cortices directly, in both cases in the beta (15-25Hz) range. Thus, although a common anatomical network may serve VSTM in different contexts, it does so via specific functions that are carried out within distinct, dynamically configured frequency channels. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Neurochemical changes in the pericalcarine cortex in congenital blindness attributable to bilateral anophthalmia.

    Science.gov (United States)

    Coullon, Gaelle S L; Emir, Uzay E; Fine, Ione; Watkins, Kate E; Bridge, Holly

    2015-09-01

    Congenital blindness leads to large-scale functional and structural reorganization in the occipital cortex, but relatively little is known about the neurochemical changes underlying this cross-modal plasticity. To investigate the effect of complete and early visual deafferentation on the concentration of metabolites in the pericalcarine cortex, (1)H magnetic resonance spectroscopy was performed in 14 sighted subjects and 5 subjects with bilateral anophthalmia, a condition in which both eyes fail to develop. In the pericalcarine cortex, where primary visual cortex is normally located, the proportion of gray matter was significantly greater, and levels of choline, glutamate, glutamine, myo-inositol, and total creatine were elevated in anophthalmic relative to sighted subjects. Anophthalmia had no effect on the structure or neurochemistry of a sensorimotor cortex control region. More gray matter, combined with high levels of choline and myo-inositol, resembles the profile of the cortex at birth and suggests that the lack of visual input from the eyes might have delayed or arrested the maturation of this cortical region. High levels of choline and glutamate/glutamine are consistent with enhanced excitatory circuits in the anophthalmic occipital cortex, which could reflect a shift toward enhanced plasticity or sensitivity that could in turn mediate or unmask cross-modal responses. Finally, it is possible that the change in function of the occipital cortex results in biochemical profiles that resemble those of auditory, language, or somatosensory cortex. Copyright © 2015 the American Physiological Society.

  1. Modified skin incision for avoiding the lesser occipital nerve and occipital artery during retrosigmoid craniotomy: potential applications for enhancing operative working distance and angles while minimizing the risk of postoperative neuralgias and intraoperative hemorrhage.

    Science.gov (United States)

    Tubbs, R Shane; Fries, Fabian N; Kulwin, Charles; Mortazavi, Martin M; Loukas, Marios; Cohen-Gadol, Aaron A

    2016-10-01

    Chronic postoperative neuralgias and headache following retrosigmoid craniotomy can be uncomfortable for the patient. We aimed to better elucidate the regional nerve anatomy in an effort to minimize this postoperative complication. Ten adult cadaveric heads (20 sides) were dissected to observe the relationship between the lesser occipital nerve and a traditional linear versus modified U incision during retrosigmoid craniotomy. Additionally, the relationship between these incisions and the occipital artery were observed. The lesser occipital nerve was found to have two types of course. Type I nerves (60%) remained close to the posterior border of the sternocleidomastoid muscle and some crossed anteriorly over the sternocleidomastoid muscle near the mastoid process. Type II nerves (40%) left the posterior border of the sternocleidomastoid muscle and swung medially (up to 4.5cm posterior to the posterior border of the sternocleidomastoid muscle) as they ascended over the occiput. The lesser occipital nerve was near a midpoint of a line between the external occipital protuberance and mastoid process in all specimens with the type II nerve configuration. Based on our findings, the inverted U incision would be less likely to injure the type II nerves but would necessarily cross over type I nerves, especially more cranially on the nerve at the apex of the incision. As the more traditional linear incision would most likely transect the type I nerves and more so near their trunk, the U incision may be the overall better choice in avoiding neural and occipital artery injury during retrosigmoid approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Morphometric analysis of hypoglossal canal of the occipital bone in Iranian dry skulls

    Directory of Open Access Journals (Sweden)

    Bayat Parvindokht

    2015-01-01

    Full Text Available Background: The hypoglossal canal (HC is in basal part of cranium that transmits the nerve that supplies the motor innervations to the muscles of tongue. Study on morphometry of (HC and its variations has been a considerable interest field to neurosurgeons and research workers especially because of their racial and regional. Material and Methods: In this retrospective study, 26 adult dry human crania of no sex known were studied for (HC and its variants. Thirty five skulls were observed for any damage of post cranial fossa and those in good condition (26 skullswere selected. Sliding Vernier caliper was used for morphometric analysis. Results: There were significant difference between distances of: a-(HC till anterior tip of condyles (right and left, b-(HC till posterior tip of condyles (right and left, c-(HCtill lower border of occipital condyles (right and left, d-(HC till external border of foramen jugular (right and left, e-(HC till opisthion(right and left, f-(HC till carotid canal (right and left, g-(HC till jugular tubercle (right and left. There wasn′t significant difference in other parameters. Conclusion: Detailed morphometric analysis of (HC will help in planning of surgical intervention of skull base in safer and easier ways.

  3. Intractable occipital lobe epilepsy: clinical characteristics and surgical treatment.

    Science.gov (United States)

    Jobst, Barbara C; Williamson, Peter D; Thadani, Vijay M; Gilbert, Karen L; Holmes, Gregory L; Morse, Richard P; Darcey, Terrance M; Duhaime, Ann-Christine; Bujarski, Krysztof A; Roberts, David W

    2010-11-01

    Intractable occipital lobe epilepsy remains a surgical challenge. Clinical characteristics of 14 patients were analyzed. Twelve patients had surgery, seven patients had visual auras (50%) and only eight patients (57%) had posterior scalp EEG changes. Ictal single-proton emission computed tomography (SPECT) incorrectly localized in 7 of 10 patients. Six patients (50%) had Engel's class I outcome. Patients with inferior occipital seizure onset appeared to fare better (three of four class I) than patients with lateral or medial occipital seizure onset (three of eight class I). Patients who had all three occipital surfaces covered with electrodes had a better outcome (four of five class I) than patients who had limited electroencephalography (EEG) coverage (two of seven class I). Magnetic resonance imaging (MRI) lesions did not guarantee a seizure free outcome. In conclusion, visual auras, scalp EEG, and imaging findings are not reliable for correct identification of occipital onset. Occipital seizure onset can be easily missed in nonlesional epilepsy. Comprehensive intracranial EEG coverage of all three occipital surfaces leads to better outcomes.

  4. Helmet-Induced Occipital Neuralgia in a Military Aviator.

    Science.gov (United States)

    Chalela, Julio A

    2018-04-01

    Headaches among military personnel are very common and headgear wear is a frequently identified culprit. Helmet wear may cause migrainous headaches, external compression headache, other primary cranial neuralgias, and occipital neuralgia. The clinical features and the response to treatment allow distinction between the different types of headaches. Headaches among aviators are particularly concerning as they may act as distractors while flying and the treatment options are often incompatible with flying status. A 24-yr-old door gunner presented with suboccipital pain associated with the wear of his helmet. He described the pain as a paroxysmal stabbing sensation coming in waves. The physical exam and history supported the diagnosis of primary occipital neuralgia. Systemic pharmacological options were discussed with the soldier, but rejected due to his need to remain in flying status. An occipital nerve block was performed with good clinical results, supporting the diagnosis of occipital neuralgia and allowing him to continue as mission qualified. Occipital neuralgia can be induced by helmet wear in military personnel. Occipital nerve block can be performed in the deployed setting, allowing the service member to remain mission capable and sparing him/her from systemic side effects.Chalela JA. Helmet-induced occipital neuralgia in a military aviator. Aerosp Med Hum Perform. 2018; 89(4):409-410.

  5. Occipital Neuralgia Diagnosis and Treatment: The Role of Ultrasound.

    Science.gov (United States)

    Narouze, Samer

    2016-04-01

    Occipital neuralgia is a form of neuropathic type of pain in the distribution of the greater, lesser, or third occipital nerves. Patients with intractable occipital neuralgia do not respond well to conservative treatment modalities. This group of patients represents a significant therapeutic challenge and may require interventional or invasive therapeutic approaches. Occipital neuralgia frequently occurs as a result of nerve entrapment or irritation by a tight muscle or vascular structure, or nerve trauma during whiplash injury. Although the entrapment theory is most commonly accepted, it lacks strong clinical evidence to support it. Accordingly, the available interventional approaches have been targeting the accessible part of the occipital nerve rather than the entrapped part. Bedside sonography is an excellent imaging modality for soft tissue structures. Ultrasound not only allows distinguishing normal from abnormal entrapped occipital nerves, it can identify the level and the cause of entrapment as well. Ultrasound guidance allows precise occipital nerve blocks and interventions at the level of the "specific" entrapment location rather than into the site of "presumed" entrapment. © 2016 American Headache Society.

  6. Long-term visual outcome after microsurgical removal of occipital lobe cavernomas.

    Science.gov (United States)

    Kivelev, Juri; Koskela, Elina; Setälä, Kirsi; Niemelä, Mika; Hernesniemi, Juha

    2012-08-01

    Cavernomas in the occipital lobe are relatively rare. Because of the proximity to the visual cortex and incoming subcortical tracts, microsurgical removal of occipital cavernomas may be associated with a risk of visual field defects. The goal of the study was to analyze long-term outcome after operative treatment of occipital cavernomas with special emphasis on visual outcome. Of the 390 consecutive patients with cavernomas who were treated at Helsinki University Central Hospital between 1980 and 2011, 19 (5%) had occipital cavernomas. Sixteen patients (4%) were surgically treated and are included in this study. The median age was 39 years (range 3-59 years). Seven patients (56%) suffered from hemorrhage preoperatively, 5 (31%) presented with visual field deficits, 11 (69%) suffered from seizures, and 4 (25%) had multiple cavernomas. Surgery was indicated for progressive neurological deterioration. The median follow-up after surgery was 5.25 years (range 0.5-14 years). All patients underwent thorough neuroophthalmological assessment to determine visual outcome after surgery. Visual fields were classified as normal, mild homonymous visual field loss (not disturbing the patient, driving allowed), moderate homonymous visual field loss (disturbing the patient, driving prohibited), and severe visual field loss (total homonymous hemianopia or total homonymous quadrantanopia). At the last follow-up, 4 patients (25%) had normal visual fields, 6 (38%) had a mild visual field deficit, 1 (6%) complained of moderate visual field impairment, and 5 (31%) had severe homonymous visual field loss. Cavernomas seated deeper than 2 cm from the pial surface carried a 4.4-fold risk of postoperative visual field deficit relative to superficial ones (p = 0.034). Six (55%) of the 11 patients presenting with seizures were seizure-free postoperatively. Eleven (69%) of 16 patients had no disability during the long-term follow-up. Surgical removal of occipital cavernomas may carry a

  7. True aneurysm of the proximal occipital artery: Case report.

    Science.gov (United States)

    Illuminati, Giulio; Cannistrà, Marco; Pizzardi, Giulia; Pasqua, Rocco; Frezzotti, Francesca; Calio', Francesco G

    2018-01-01

    True aneurysms of the proximal occipital artery are rare, may cause neurological symptoms due to compression of the hypoglossal nerve and their resection may be technically demanding. The case of an aneurysm of the proximal occipital artery causing discomfort and tongue deviation by compression on the hypoglossal nerve is reported. Postoperative course after resection was followed by complete regression of symptoms. Surgical resection, as standard treatment of aneurysms of the occipital artery, with the eventual technical adjunct of intubation by the nose is effective in durably relieving symptoms and preventing aneurysm-related complication. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Anton's Syndrome due to Bilateral Ischemic Occipital Lobe Strokes.

    Science.gov (United States)

    Zukić, Sanela; Sinanović, Osman; Zonić, Lejla; Hodžić, Renata; Mujagić, Svjetlana; Smajlović, Edina

    2014-01-01

    We present a case of a patient with Anton's syndrome (i.e., visual anosognosia with confabulations), who developed bilateral occipital lobe infarct. Bilateral occipital brain damage results in blindness, and patients start to confabulate to fill in the missing sensory input. In addition, the patient occasionally becomes agitated and talks to himself, which indicates that, besides Anton's syndrome, he might have had Charles Bonnet syndrome, characterized by both visual loss and hallucinations. Anton syndrome, is not so frequent condition and is most commonly caused by ischemic stroke. In this particular case, the patient had successive bilateral occipital ischemia as a result of massive stenoses of head and neck arteries.

  9. Distribution of catecholamines and serotonin in the rat cerebral cortex:

    International Nuclear Information System (INIS)

    Reader, T.A.

    1981-01-01

    The rat cerebral cortex was dissected in five regions and analyzed for the catecholamines noradrenaline, adrenaline and dopamine, and for the indoleamine seroton in using sensitive radioenzymatic assay methods with thin-layer-chromatography. The noradrenaline concentration was highest in the ventral cortex, lateral to the hypothalamus, had intermediate values for the prefrontal, frontal and parietal cortical areas and was lowest in the occipital cortex. Dopamine levels were also highest in the cortex lateral to the hypothalamus, and moderate in the prefrontal and frontal cortical areas, with the lowest values measured for the occipital cortex. The ratios dopamine/noradrenaline further support the hypothesis that they are independent transmitters. Traces of adrenaline were measured in all regions examined. The serotonin distribution was found to be non-homogeneous, with the highest values for the prefrontal cortex and ventral cortex lateral to the hypothalamus. The functional significance of these amines and their ratios are discussed in relation to their role as putative modulators of cortical neuronal excitability. (author)

  10. C1-C2 instability with severe occipital headache in the setting of vertebral artery facet complex erosion.

    Science.gov (United States)

    Taher, Fadi; Bokums, Kristaps; Aichmair, Alexander; Hughes, Alexander P

    2014-05-01

    An exact understanding of patient vertebral artery anatomy is essential to safely place screws at the atlanto-axial level in posterior arthrodesis. We aim to report a case of erosion of the left vertebral artery into the C1-C2 facet complex with resultant rotatory and lateral listhesis presenting with severe occipital headache. This represents a novel etiology for this diagnosis and our report illustrates technical considerations when instrumenting the C1-C2 segment. We report a case of severe occipital headache due to C1-C2 instability with resultant left C2 nerve compression in the setting of erosion of the vertebral artery into the C1-C2 facet complex. A 68-year-old woman presented with a 12-month history of progressively debilitating headache and neck pain with atlanto-axial instability. Computed tomography (CT) angiography demonstrated erosion of the left vertebral artery into the left C1-C2 facet complex. In addition, the tortuous vertebral arteries had eroded into the C2 pedicles, eliminating the possibility for posterior pedicle screw placement. The patient underwent posterior arthrodesis of C1-C2 utilizing bilateral lateral mass fixation into C1 and bilateral trans-laminar fixation into C2 with resolution of all preoperative complaints. This study constitutes the first report of a tortuous vertebral artery causing the partial destruction of a C1-C2 facet complex, as well as instability, with the clinical presentation of severe occipital headache. It hereby presents a novel etiology for both the development of C1-C2 segment instability as well as the development of occipital headache. Careful evaluation of such lesions utilizing CT angiography is important when formulating a surgical plan.

  11. Quantitative Magnetic Resonance Imaging of Brainstem Volumes, Plaques, and Surface Area in the Occipital Regions of Patients with Multiple Sclerosis

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    Alper, F.; Kantarci, M.; Altunkaynak, E.; Varoglu, A. O.; Karaman, A.; Oral, E.; Okur, A. [Ataturk Univ., Erzurum (Turkey). Depts. of Radiology, Histology, Neurology and Embryology, Psychiatry

    2006-07-15

    Purpose: To determine brainstem volumes, number of plaques, and surface areas in the occipital lobes of patients with relapsing remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS), and to investigate whether there is any correlation between brainstem volume and the number/surface areas of plaque in the occipital lobes. Material and Methods: Magnetic resonance imaging was obtained on 14 relapsing-remitting (RR) and 13 secondary progressive (SP) MS patients and 26 female control subjects. The Cavalieri method was used by modern design stereology to measure brainstem volume. The point-counting grid was used to evaluate sclerotic plaque surface areas in the occipital lobe. The number of plaques in the imaging section was calculated. Results: Brainstem volumes for RR and SP with multiple sclerosis and control subjects were 3647 mm{sup 3} , 3515 mm{sup 3} , and 4517 mm{sup 3} , respectively. Mean number of plaques in the right-left occipital lobe was found to be 2.7-3.4 in RR-MS and 5.2-2.8 in SP-MS. Mean plaque surface area in the right-left occipital lobe was determined to be 58.52-88.24 mm{sup 2} in RR MS and 124.3-64.82 mm{sup 2} in SP MS. Brainstem volumes were significantly reduced in both groups of patients with MS compared to controls ( P <0.01). Conclusion: Magnetic-resonance-estimated volume and surface area values in multiple sclerosis may facilitate our understanding of the clinical situation of patients and provide a simple index for evaluating therapeutic efficiency.

  12. Quantitative Magnetic Resonance Imaging of Brainstem Volumes, Plaques, and Surface Area in the Occipital Regions of Patients with Multiple Sclerosis

    International Nuclear Information System (INIS)

    Alper, F.; Kantarci, M.; Altunkaynak, E.; Varoglu, A. O.; Karaman, A.; Oral, E.; Okur, A.

    2006-01-01

    Purpose: To determine brainstem volumes, number of plaques, and surface areas in the occipital lobes of patients with relapsing remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS), and to investigate whether there is any correlation between brainstem volume and the number/surface areas of plaque in the occipital lobes. Material and Methods: Magnetic resonance imaging was obtained on 14 relapsing-remitting (RR) and 13 secondary progressive (SP) MS patients and 26 female control subjects. The Cavalieri method was used by modern design stereology to measure brainstem volume. The point-counting grid was used to evaluate sclerotic plaque surface areas in the occipital lobe. The number of plaques in the imaging section was calculated. Results: Brainstem volumes for RR and SP with multiple sclerosis and control subjects were 3647 mm 3 , 3515 mm 3 , and 4517 mm 3 , respectively. Mean number of plaques in the right-left occipital lobe was found to be 2.7-3.4 in RR-MS and 5.2-2.8 in SP-MS. Mean plaque surface area in the right-left occipital lobe was determined to be 58.52-88.24 mm 2 in RR MS and 124.3-64.82 mm 2 in SP MS. Brainstem volumes were significantly reduced in both groups of patients with MS compared to controls ( P <0.01). Conclusion: Magnetic-resonance-estimated volume and surface area values in multiple sclerosis may facilitate our understanding of the clinical situation of patients and provide a simple index for evaluating therapeutic efficiency

  13. Occipital transtentorial/falcine approach, a "cross-court" trajectory to accessing contralateral posterior thalamic lesions: case report.

    Science.gov (United States)

    Iwami, Kenichiro; Fujii, Masazumi; Saito, Kiyoshi

    2017-07-01

    Surgical treatment of lesions in the posterior thalamus, especially those extending laterally, is technically challenging because of a deep surgical field, narrow operative corridor, and the surrounding critical neurovascular structures. The authors describe an occipital transtentorial/falcine approach (OTFA) that was successfully used in the treatment of a cavernous malformation (CM) extending laterally from thalamus to midbrain. A 40-year-old man complained of progressive right hemiparesis and numbness. Radiological evaluation revealed a large CM in the left thalamus, surfacing on the pulvinar thalami, and extending 4 cm laterally from the midline. In addition to the usual procedures of a right-sided occipital transtentorial approach, the authors incised the falx cerebri to expand the operative corridor to the left thalamus. They achieved generous exposure of the left thalamus through a "cross-court" oblique trajectory while avoiding excessive retraction on the occipital lobe. The CM was completely removed, and no newly developed or worsening deficits were detected postoperatively. To better understand the OTFA and its application, the authors performed a cadaveric dissection. The OTFA provides increased exposure of the posterior thalamus without cortical incision and facilitates lateral access to this area through the "cross-court" operative corridor. This approach adds to the armamentarium for neurosurgeons treating thalamic lesions.

  14. Computed Tomography-Based Occipital Condyle Morphometry in an Indian Population to Assess the Feasibility of Condylar Screws for Occipitocervical Fusion.

    Science.gov (United States)

    Srivastava, Abhishek; Nanda, Geetanjali; Mahajan, Rajat; Nanda, Ankur; Mishra, Nirajana; Karmaran, Srinivasa; Batra, Sahil; Chhabra, Harvinder Singh

    2017-12-01

    A retrospective computed tomography (CT)-based morphometric study of 82 occipital condyles in the Indian population, focusing on critical morphometric dimensions with relation to placing condylar screws. This study focused on determining the feasibility of placing occipital condylar screws in an Indian population using CT anatomical morphometric data. The occipital condylar screw is a novel technique being explored as one of the options in occipitocervical stabilization. Sex and ethnic variations in anatomical structures may restrict the feasibility of this technique in some populations. To the best of our knowledge, there are no CT-based data on an Indian population that assess the feasibility of occipital condylar screws. We measured the dimensions of 82 occipital condyles in 41 adults on coronal, sagittal, and axial reconstructed CT images. The differences were noted between the right and left sides and also between males and females. Statistical analysis was performed using the t -test, with a p -value of occipital condyle shows that condylar screws are anatomically feasible in a large portion of the Indian population. However, because a small number of population may not be suitable for this technique, meticulous study of preoperative anatomy using detailed CT data is advised.

  15. Memory for shape reactivates the lateral occipital complex.

    Science.gov (United States)

    Karanian, Jessica M; Slotnick, Scott D

    2015-04-07

    Memory is thought to be a constructive process in which the cortical regions associated with processing event features are reactivated during retrieval. Although there is evidence for non-detailed cortical reactivation during retrieval (e.g., memory for visual or auditory information reactivates the visual or auditory processing regions, respectively), there is limited evidence that memory can reactivate cortical regions associated with processing detailed, feature-specific information. Such evidence is critical to our understanding of the mechanisms of episodic retrieval. The present functional magnetic resonance imaging (fMRI) study assessed whether the lateral occipital complex (LOC), a region that preferentially processes shape, is associated with retrieval of shape information. During encoding, participants were presented with colored abstract shapes that were either intact or scrambled. During retrieval, colored disks were presented and participants indicated whether the corresponding shape was previously "intact" or "scrambled". To assess whether conscious retrieval of intact shapes reactivated LOC, we conducted a conjunction of shape perception/encoding and accurate versus inaccurate retrieval of intact shapes, which produced many activations in LOC. To determine whether activity in LOC was specific to intact shapes, we conducted a conjunction of shape perception/encoding and intact versus scrambled shapes, which also produced many activations in LOC. Furthermore, memory for intact shapes in each hemifield produced contralateral activity in LOC (e.g., memory for left visual field intact shapes activated right LOC), which reflects the specific reinstatement of perception/encoding activity. The present results extend previous feature-specific memory reactivation evidence and support the view that memory is a constructive process. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Visual interhemispheric communication and callosal connections of the occipital lobes.

    Science.gov (United States)

    Berlucchi, Giovanni

    2014-07-01

    Callosal connections of the occipital lobes, coursing in the splenium of the corpus callosum, have long been thought to be crucial for interactions between the cerebral hemispheres in vision in both experimental animals and humans. Yet the callosal connections of the temporal and parietal lobes appear to have more important roles than those of the occipital callosal connections in at least some high-order interhemispheric visual functions. The partial intermixing and overlap of temporal, parietal and occipital callosal connections within the splenium has made it difficult to attribute the effects of splenial pathological lesions or experimental sections to splenial components specifically related to select cortical areas. The present review describes some current contributions from the modern techniques for the tracking of commissural fibers within the living human brain to the tentative assignation of specific visual functions to specific callosal tracts, either occipital or extraoccipital. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Malignant melanotic neuroectodermal tumour of infancy affecting the occipital squama.

    Directory of Open Access Journals (Sweden)

    Patankar T

    1998-07-01

    Full Text Available An unusual case of a melanotic neuroectodermal tumour of the occipital squama, which underwent malignant transformation in a nine-month-old infant is reported and pertinent literature reviewed.

  18. Lateralization of the posterior parietal cortex for internal monitoring of self- versus externally generated movements.

    Science.gov (United States)

    Ogawa, Kenji; Inui, Toshio

    2007-11-01

    Internal monitoring or state estimation of movements is essential for human motor control to compensate for inherent delays and noise in sensorimotor loops. Two types of internal estimation of movements exist: self-generated movements, and externally generated movements. We used functional magnetic resonance imaging to investigate differences in brain activity for internal monitoring of self- versus externally generated movements during visual occlusion. Participants tracked a sinusoidally moving target with a mouse cursor. On some trials, vision of either target (externally generated) or cursor (self-generated) movement was transiently occluded, during which subjects continued tracking by estimating current position of either the invisible target or cursor on screen. Analysis revealed that both occlusion conditions were associated with increased activity in the presupplementary motor area and decreased activity in the right lateral occipital cortex compared to a control condition with no occlusion. Moreover, the right and left posterior parietal cortex (PPC) showed greater activation during occlusion of target and cursor movements, respectively. This study suggests lateralization of the PPC for internal monitoring of internally versus externally generated movements, fully consistent with previously reported clinical findings.

  19. Dorsal and ventral changes of the occipital vertebrae

    International Nuclear Information System (INIS)

    Banki, Z.

    1981-01-01

    Based on his own observation and on the literature, the author discusses various types of calcification in the occipital-cervical region, beginning with those situated dorsally and followed by ventral forms. An attempt is made to classify these changes, depending on their morphology and situation, from an embryological point of view. The pro-atlantal and ante pro-atlanto origin of the occipital vertebrae is discussed. Differentiation depends on appearances. (orig.) [de

  20. Decreased occipital lobe metabolism by FDG-PET/CT

    Science.gov (United States)

    Solnes, Lilja; Nalluri, Abhinav; Cohen, Jesse; Jones, Krystyna M.; Zan, Elcin; Javadi, Mehrbod S.; Venkatesan, Arun

    2017-01-01

    Objective: To compare brain metabolism patterns on fluorodeoxyglucose (FDG)-PET/CT in anti–NMDA receptor and other definite autoimmune encephalitis (AE) and to assess how these patterns differ between anti–NMDA receptor neurologic disability groups. Methods: Retrospective review of clinical data and initial dedicated brain FDG-PET/CT studies for neurology inpatients with definite AE, per published consensus criteria, treated at a single academic medical center over a 10-year period. Z-score maps of FDG-PET/CT were made using 3-dimensional stereotactic surface projections in comparison to age group–matched controls. Brain region mean Z scores with magnitudes ≥2.00 were interpreted as significant. Comparisons were made between anti–NMDA receptor and other definite AE patients as well as among patients with anti–NMDA receptor based on modified Rankin Scale (mRS) scores at the time of FDG-PET/CT. Results: The medial occipital lobes were markedly hypometabolic in 6 of 8 patients with anti–NMDA receptor encephalitis and as a group (Z = −4.02, interquartile range [IQR] 2.14) relative to those with definite AE (Z = −2.32, 1.46; p = 0.004). Among patients with anti–NMDA receptor encephalitis, the lateral and medial occipital lobes were markedly hypometabolic for patients with mRS 4–5 (lateral occipital lobe Z = −3.69, IQR 1; medial occipital lobe Z = −4.08, 1) compared with those with mRS 0–3 (lateral occipital lobe Z = −0.83, 2; p occipital lobe Z = −1.07, 2; p = 0.001). Conclusions: Marked medial occipital lobe hypometabolism by dedicated brain FDG-PET/CT may serve as an early biomarker for discriminating anti–NMDA receptor encephalitis from other AE. Resolution of lateral and medial occipital hypometabolism may correlate with improved neurologic status in anti–NMDA receptor encephalitis. PMID:29159205

  1. An Anatomic Morphological Study of Occipital Spurs in Human Skulls.

    Science.gov (United States)

    Srivastava, Monika; Asghar, Adil; Srivastava, Nitya Nand; Gupta, Nandkishore; Jain, Anuj; Verma, Jayant

    2018-01-01

    Occipital spurs are quite common; however, they are also the source of frequent discomfort to the patients. Their role has been implicated in causation of pain at the base of skull, which may extend to shoulder limiting the movement of the shoulder and neck. The present was carried out to find out the prevalence of occipital spur in human skull and to find out the anatomic morphological characteristics of occipital spur. A total of 30 cadaveric skulls were examined in the Department of Anatomy, Uttar Pradesh University of Medical Sciences, for the presence of occipital spur. These skulls were the part of boneset obtained as a part of undergraduate training in the department. All the measurements were taken using a digital Vernier Caliper after taking all necessary precaution to avoid any damage to these spurs. The prevalence of occipital spur in the present study was 10%. The mean width recorded in the present study was 13.40 mm (±6.7) and the mean length recorded was 13.45 mm (±1.05). Similarly, mean thickness noted was 2.43 mm (±0.43). Thus, the present study concludes that occipital spurs are the frequent source of discomfort to patients. The knowledge of this tubercle is of paramount importance to neurosurgeons, sports physicians, and radiologists for the diagnosis of such discomfort.

  2. Giant Atretic Occipital Lipoencephalocele in an Adult with Bony Outgrowth.

    Science.gov (United States)

    Nimkar, Kshama; Sood, Dinesh; Soni, Pawan; Chauhan, Narvir; Surya, Mukesh

    2016-01-01

    We present unique case of a giant extracranial atretic occipital lipoencephalocele in an adult patient with new bone formation within it which was not associated with any developmental malformation of brain. Resection of the lipoencephalocele was performed for esthetic reasons. 18 year old female patient presented to the surgery OPD with complains of a large mass in the occipital region present since birth. It was of size of a betel nut at the time of birth and gradually increased in size over a long period of time. It was painless and not associated with any other constitutional symptoms. On examination the rounded fluctuant mass was present in the midline in occipital region covered with alopecic skin with dimpling in the overlying skin. On MRI there was mass showing both T1 and T2 hyperintense signal area suggestive of fat component. Herniation of meninges and atretic brain parenchyma was also seen through a defect in the occipital bone in the midline. There was a Y shaped bony outgrowth seen arising from occipital bone into the mass which was quite unusual in association with an atretic lipoencephalocele. A large lipoencephalocele with bony outgrowth in an adult patient is a rare presentation of atreic occipital encephalocele.

  3. Neonatal apneic seizure of occipital lobe origin: continuous video-EEG recording.

    Science.gov (United States)

    Castro Conde, José Ramón; González-Hernández, Tomás; González Barrios, Desiré; González Campo, Candelaria

    2012-06-01

    We present 2 term newborn infants with apneic seizure originating in the occipital lobe that was diagnosed by video-EEG. One infant had ischemic infarction in the distribution of the posterior cerebral artery, extending to the cingulate gyrus. In the other infant, only transient occipital hyperechogenicity was observed by using neurosonography. In both cases, although the critical EEG discharge was observed at the occipital level, the infants presented no clinical manifestations. In patient 1, the discharge extended to the temporal lobe first, with subtle motor manifestations and tachycardia, then synchronously to both hemispheres (with bradypnea/hypopnea), and the background EEG activity became suppressed, at which point the infant experienced apnea. In patient 2, background EEG activity became suppressed right at the end of the focal discharge, coinciding with the appearance of apnea. In neither case did the clinical description by observers coincide with video-EEG findings. The existence of connections between the posterior limbic cortex and the temporal lobe and midbrain respiratory centers may explain the clinical symptoms recorded in these 2 cases. The novel features reported here include video-EEG capture of apneic seizure, ischemic lesion in the territory of the posterior cerebral artery as the cause of apneic seizure, and the appearance of apnea when the epileptiform ictal discharge extended to other cerebral areas or when EEG activity became suppressed. To date, none of these clinical findings have been previously reported. We believe this pathology may in fact be fairly common, but that video-EEG monitoring is essential for diagnosis.

  4. Rapid and reversible recruitment of early visual cortex for touch.

    Directory of Open Access Journals (Sweden)

    Lotfi B Merabet

    2008-08-01

    Full Text Available The loss of vision has been associated with enhanced performance in non-visual tasks such as tactile discrimination and sound localization. Current evidence suggests that these functional gains are linked to the recruitment of the occipital visual cortex for non-visual processing, but the neurophysiological mechanisms underlying these crossmodal changes remain uncertain. One possible explanation is that visual deprivation is associated with an unmasking of non-visual input into visual cortex.We investigated the effect of sudden, complete and prolonged visual deprivation (five days in normally sighted adult individuals while they were immersed in an intensive tactile training program. Following the five-day period, blindfolded subjects performed better on a Braille character discrimination task. In the blindfold group, serial fMRI scans revealed an increase in BOLD signal within the occipital cortex in response to tactile stimulation after five days of complete visual deprivation. This increase in signal was no longer present 24 hours after blindfold removal. Finally, reversible disruption of occipital cortex function on the fifth day (by repetitive transcranial magnetic stimulation; rTMS impaired Braille character recognition ability in the blindfold group but not in non-blindfolded controls. This disruptive effect was no longer evident once the blindfold had been removed for 24 hours.Overall, our findings suggest that sudden and complete visual deprivation in normally sighted individuals can lead to profound, but rapidly reversible, neuroplastic changes by which the occipital cortex becomes engaged in processing of non-visual information. The speed and dynamic nature of the observed changes suggests that normally inhibited or masked functions in the sighted are revealed by visual loss. The unmasking of pre-existing connections and shifts in connectivity represent rapid, early plastic changes, which presumably can lead, if sustained and

  5. Type III occipital condylar fracture presenting with hydrocephalus, vertebral artery injury and vasospasm: case report

    International Nuclear Information System (INIS)

    Menendez, J.A.; Baskaya, M.K.; Day, M.A.; Nanda, A.

    2001-01-01

    Occipital condylar fractures (OCF) are rare and have a high mortality rate. We report a patient with OCF who presented with acute hydrocephalus and died from diffuse vasospasm secondary to vertebral artery injury. A 45-year-old man fell 20 feet from a deer stand and landed on his head. CT showed a type III OCF continuing to the anterior rim of the foramen magnum on the left, with a bone fragment pushing into the medulla, causing hydrocephalus. The patient was stabilized, and a four-vessel arteriogram showed diffuse vasospasm with complete occlusion of the left vertebral artery at the level of the OCF. To our knowledge, this is the first documented case of the conjunction of OCF, hydrocephalus, and vasospasm. (orig.)

  6. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection.

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity.

  7. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity. PMID:26063964

  8. Reduced resting-state functional connectivity of the somatosensory cortex predicts psychopathological symptoms in women with bulimia nervosa.

    Science.gov (United States)

    Lavagnino, Luca; Amianto, Federico; D'Agata, Federico; Huang, Zirui; Mortara, Paolo; Abbate-Daga, Giovanni; Marzola, Enrica; Spalatro, Angela; Fassino, Secondo; Northoff, Georg

    2014-01-01

    Alterations in the resting-state functional connectivity (rs-FC) of several brain networks have been demonstrated in eating disorders. However, very few studies are currently available on brain network dysfunctions in bulimia nervosa (BN). The somatosensory network is central in processing body-related stimuli and it may be altered in BN. The present study therefore aimed to investigate rs-FC in the somatosensory network in bulimic women. Sixteen medication-free women with BN (age = 23 ± 5 years) and 18 matched controls (age = 23 ± 3 years) underwent a functional magnetic resonance resting-state scan and assessment of eating disorder symptoms. Within-network and seed-based functional connectivity analyses were conducted to assess rs-FC within the somatosensory network and to other areas of the brain. Bulimia nervosa patients showed a decreased rs-FC both within the somatosensory network (t = 9.0, df = 1, P = 0.005) and with posterior cingulate cortex and two visual areas (the right middle occipital gyrus and the right cuneus) (P = 0.05 corrected for multiple comparison). The rs-FC of the left paracentral lobule with the right middle occipital gyrus correlated with psychopathology measures like bulimia (r = -0.4; P = 0.02) and interoceptive awareness (r = -0.4; P = 0.01). Analyses were conducted using age, BMI (body mass index), and depressive symptoms as covariates. Our findings show a specific alteration of the rs-FC of the somatosensory cortex in BN patients, which correlates with eating disorder symptoms. The region in the right middle occipital gyrus is implicated in body processing and is known as extrastriate body area (EBA). The connectivity between the somatosensory cortex and the EBA might be related to dysfunctions in body image processing. The results should be considered preliminary due to the small sample size.

  9. Sub-occipital craniectomy in a lion (Panthera leo) with occipital bone malformation and hypovitaminosis A.

    Science.gov (United States)

    Shamir, Merav H; Shilo, Yael; Fridman, Alon; Chai, Orit; Reifen, Ram; Miara, Limor

    2008-09-01

    Neurologic dysfunction accompanied by malformation of both the skull and the cervical vertebrae has been previously described in lions kept in captivity worldwide, and this dysfunction and malformation were most often related to vitamin A deficiency. Diagnosis of the bone malformation and its effects on the neural tissue was until recently limited to postmortem examination, with characteristic thickening of the bones of the cranial vault, cerebellar herniation, compression of the foramen magnum, and enlargement of the lateral ventricles. For some mildly affected lion cubs with neurologic signs, improvement was reported with excessive vitamin A supplementation. However, definitive diagnosis was only available for those that eventually died or were euthanized. This case documents the antemortem diagnosis of the disease using computed tomographic imaging and liver biopsy. While conservative treatment failed, suboccipital craniectomy removed the thickened occipital bone and was demonstrated to be a successful surgical intervention that can be used to treat more severely affected lions.

  10. Exploratory metabolomic analyses reveal compounds correlated with lutein concentration in frontal cortex, hippocampus, and occipital cortex of human infant brain

    Science.gov (United States)

    Lutein is a dietary carotenoid well known for its role as an antioxidant in the macula and recent reports implicate a role for lutein in cognitive function. Lutein is the dominant carotenoid in both pediatric and geriatric brain tissue. In addition, cognitive function in older adults correlated with...

  11. Benign occipital lobe seizures: Natural progression and atypical evolution

    Directory of Open Access Journals (Sweden)

    Prithika Chary

    2013-01-01

    Full Text Available Benign occipital seizure syndromes are benign childhood epilepsy syndromes and are mainly of two types, Panayiotopoulos syndrome, an autonomic epilepsy and idiopathic childhood occipital epilepsy of Gastaut (ICOE-G including the idiopathic photosensitive occipital lobe epilepsy. Although both these types are categorized as occipital seizures, they are distinct in presentation and management. They can also be tricky to diagnose as visual symptoms may not always be the presenting feature and it is also not very easy to elicit visual hallucinations during history taking. These seizures have a good response to treatment; however, there could be atypical evolution and refractoriness to treatment especially with ICOE-G. We describe three children who presented with visual and non-visual symptoms and the electroencephalography (EEG in all the three cases showed occipital paroxysms. We have emphasized the clues in the clinical history and EEG leading to the diagnosis of these distinct epilepsy syndromes. We have also discussed the natural course of these epilepsy syndromes with some atypical evolution, which clinicians need to be aware of during treatment of these children.

  12. Benign occipital lobe seizures: Natural progression and atypical evolution.

    Science.gov (United States)

    Chary, Prithika; Rajendran, Bhuvaneshwari

    2013-10-01

    Benign occipital seizure syndromes are benign childhood epilepsy syndromes and are mainly of two types, Panayiotopoulos syndrome, an autonomic epilepsy and idiopathic childhood occipital epilepsy of Gastaut (ICOE-G) including the idiopathic photosensitive occipital lobe epilepsy. Although both these types are categorized as occipital seizures, they are distinct in presentation and management. They can also be tricky to diagnose as visual symptoms may not always be the presenting feature and it is also not very easy to elicit visual hallucinations during history taking. These seizures have a good response to treatment; however, there could be atypical evolution and refractoriness to treatment especially with ICOE-G. We describe three children who presented with visual and non-visual symptoms and the electroencephalography (EEG) in all the three cases showed occipital paroxysms. We have emphasized the clues in the clinical history and EEG leading to the diagnosis of these distinct epilepsy syndromes. We have also discussed the natural course of these epilepsy syndromes with some atypical evolution, which clinicians need to be aware of during treatment of these children.

  13. Versive seizures in occipital lobe epilepsy: lateralizing value and pathophysiology.

    Science.gov (United States)

    Usui, Naotaka; Mihara, Tadahiro; Baba, Koichi; Matsuda, Kazumi; Tottori, Takayasu; Umeoka, Shuichi; Kondo, Akihiko; Nakamura, Fumihiro; Terada, Kiyohito; Usui, Keiko; Inoue, Yushi

    2011-11-01

    To clarify the value of versive seizures in lateralizing and localizing the epileptogenic zone in patients with occipital lobe epilepsy, we studied 13 occipital lobe epilepsy patients with at least one versive seizure recorded during preoperative noninvasive video-EEG monitoring, who underwent occipital lobe resection, and were followed postoperatively for more than 2 years with Engel's class I outcome. The videotaped versive seizures were analyzed to compare the direction of version and the side of surgical resection in each patient. Moreover, we examined other motor symptoms (partial somatomotor manifestations such as tonic and/or clonic movements of face and/or limbs, automatisms, and eyelid blinking) associated with version. Forty-nine versive seizures were analyzed. The direction of version was always contralateral to the side of resection except in one patient. Among accompanying motor symptoms, partial somatomotor manifestations were observed in only five patients. In conclusion, versive seizure is a reliable lateralizing sign indicating contralateral epileptogenic zone in occipital lobe epilepsy. Since versive seizures were accompanied by partial somatomotor manifestations in less than half of the patients, it is suggested that the mechanism of version in occipital lobe epilepsy is different from that in frontal lobe epilepsy. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Supra- and infra-torcular double occipital encephalocele.

    Science.gov (United States)

    Canaz, Hüseyin; Ayçiçek, Ezgi; Akçetin, Mustafa Ali; Akdemir, Osman; Alataş, Ibrahim; Özdemir, Bülent

    2015-01-01

    An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull that is closed or covered with skin. Occipital encephaloceles are the most frequent type in North America and Western Europe, where about 85% of encephaloceles take this form. To the best of our knowledge, there are only three other reported cases of double occipital encephaloceles in the literature. The current study reports a double and both supra- and infra-torcular occipital encephalocele in a neonate and discusses the importance of preoperative neuroimaging studies to optimize the outcome. The patient was a 1-day-old male child who was identified by prenatal ultrasound to have two occipital encephaloceles. The patient underwent a closure of the occipital encephalocele on the second postnatal day. The infant tolerated the procedure well and was extubated on the first postoperative day. The child continues to do well during follow-up. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  15. [Treatment of Occipital Neuralgia by Electroacupuncture Combined with Neural Mobilization].

    Science.gov (United States)

    Wang, Yan; Guo, Zi-Nan; Yang, Zhen; Wang, Shun

    2018-03-25

    To observe the effect of electroacupuncture (EA) combined with neural mobilization (NM) in the treatment of occipital neuralgia. A total of 62 occipital neuralgia patients were randomized into EA group (19 cases), NM group (22 cases) and EA+NM group (21 cases). EA was applied at acupoint-pairs as Yuzhen (BL 9)- Tianzhu (BL 10), Fengchi (GB 20)- Wangu (GB 12), etc. NM intervention consisted of occipital muscle group mobilization, C 2 spinous process mobilization, cervical joint passive movement management mobilization, etc., was performed at the impaired cervical spine segment. The two methods were used in combination for patients in the EA+NM group. All the treatment was given once a day for 2 weeks. Before and after treatment, the visual analogue scale (VAS) and the 6-point (1-6 points) behavioral rating scale (BRS-6) of headache were used to assess the severity of pain. The therapeutic effect was evaluated according to the "Criteria for Diagnosis and Cure-Improvement of Clinical Conditions" formulated by State Administration of Traditional Chinese Medicine of the People's Republic of China in 1994. After treatment, both VAS and BRS-6 scores were significantly lower than those before treatment in each of the three groups ( P occipital neuralgia, and EA+NM has a synergic analgesic effect for occipital neuralgia.

  16. 1H magnetic resonance spectroscopy evidence for occipital involvement in treatment-naive paediatric obsessive-compulsive disorder.

    Science.gov (United States)

    Ljungberg, Maria; Nilsson, Marie K L; Melin, Karin; Jönsson, Lars; Carlsson, Arvid; Carlsson, Åsa; Forssell-Aronsson, Eva; Ivarsson, Tord; Carlsson, Maria; Starck, Göran

    2017-06-01

    Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder leading to considerable distress and disability. Therapies are effective in a majority of paediatric patients, however, many only get partial response. It is therefore important to study the underlying pathophysiology of the disorder. 1H magnetic resonance spectroscopy (MRS) was used to study the concentration of brain metabolites in four different locations (cingulate gyrus and sulcus, occipital cortex, thalamus and right caudate nucleus). Treatment-naive children and adolescents with OCD (13 subjects) were compared with a group of healthy age- and gender-matched subjects (11 subjects). Multivariate analyses were performed on the concentration values. No separation between controls and patients was found. However, a correlation between metabolite concentrations and symptom severity as measured with the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) was found. Strongest was the correlation with the CY-BOCS obsession subscore and aspartate and choline in the caudate nucleus (positively correlated with obsessions), lipids at 2 and 0.9 ppm in thalamus, and occipital glutamate+glutamine, N-acetylaspartate and myo-inosytol (negatively correlated with obsessions). The observed correlations between 1H MRS and CY-BOCS in treatment-naive patients further supports an occipital involvement in OCD. The results are consistent with our previous study on adult OCD patients. The 1H MRS data were not supportive of a separation between the patient and control groups.

  17. TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

    DEFF Research Database (Denmark)

    Ptito, M; Fumal, A; de Noordhout, A Martens

    2008-01-01

    . The number of cortical sites inducing tactile sensations appeared to be related to the number of hours of Braille reading per day, Braille reading speed and dexterity. These data, taken in conjunction with previous anatomical, behavioural and functional imaging results, suggest the presence of a polysynaptic...

  18. Macular pigment carotenoids in the retina and occipital cortex are related in humans

    Science.gov (United States)

    Objectives: Lutein and zeaxanthin are dietary carotenoids that preferentially accumulate in the macular region of the retina. Together with mesozeaxanthin, a conversion product of lutein in the macula, they form the macular pigment. Lutein is also the predominant carotenoid in human brain tissue and...

  19. Occipital lobe epilepsy with fear as leading ictal symptom.

    Science.gov (United States)

    Oehl, Bernhard; Schulze-Bonhage, Andreas; Lanz, Michael; Brandt, Armin; Altenmüller, Dirk-Matthias

    2012-03-01

    Ictal fear is a semiological feature which is commonly associated with mesial temporal lobe epilepsy. Here, we describe fear as a leading symptom in cryptogenic occipital lobe epilepsy. In a patient with negative MRI findings, intracranial EEG recordings documented a strict correlation between habitual ictal anxiety attacks and both spontaneous and stimulation-induced epileptic activity in a right occipital epileptogenic area with subsequent spreading to the symptomatogenic zone in the amygdala. Circumscribed occipital topectomy led to seizure freedom. Episodes of non-epileptic fear ceased shortly afterwards. This report provides insight into pathways of propagation of epileptic activity, illustrates different etiologies of pathologic fear and underlines the importance of ictal EEG recordings. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Pathways of the inferior frontal occipital fasciculus in overt speech and reading.

    Science.gov (United States)

    Rollans, Claire; Cheema, Kulpreet; Georgiou, George K; Cummine, Jacqueline

    2017-11-19

    In this study, we examined the relationship between tractography-based measures of white matter integrity (ex. fractional anisotropy [FA]) from diffusion tensor imaging (DTI) and five reading-related tasks, including rapid automatized naming (RAN) of letters, digits, and objects, and reading of real words and nonwords. Twenty university students with no reported history of reading difficulties were tested on all five tasks and their performance was correlated with diffusion measures extracted through DTI tractography. A secondary analysis using whole-brain Tract-Based Spatial Statistics (TBSS) was also used to find clusters showing significant negative correlations between reaction time and FA. Results showed a significant relationship between the left inferior fronto-occipital fasciculus FA and performance on the RAN of objects task, as well as a strong relationship to nonword reading, which suggests a role for this tract in slower, non-automatic and/or resource-demanding speech tasks. There were no significant relationships between FA and the faster, more automatic speech tasks (RAN of letters and digits, and real word reading). These findings provide evidence for the role of the inferior fronto-occipital fasciculus in tasks that are highly demanding of orthography-phonology translation (e.g., nonword reading) and semantic processing (e.g., RAN object). This demonstrates the importance of the inferior fronto-occipital fasciculus in basic naming and suggests that this tract may be a sensitive predictor of rapid naming performance within the typical population. We discuss the findings in the context of current models of reading and speech production to further characterize the white matter pathways associated with basic reading processes. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Posterior cortex epilepsy surgery in childhood and adolescence: Predictors of long-term seizure outcome.

    Science.gov (United States)

    Ramantani, Georgia; Stathi, Angeliki; Brandt, Armin; Strobl, Karl; Schubert-Bast, Susanne; Wiegand, Gert; Korinthenberg, Rudolf; van Velthoven, Vera; Zentner, Josef; Schulze-Bonhage, Andreas; Bast, Thomas

    2017-03-01

    We aimed to investigate the long-term seizure outcome of children and adolescents who were undergoing epilepsy surgery in the parietooccipital cortex and determine their predictive factors. We retrospectively analyzed the data of 50 consecutive patients aged 11.1 (mean) ± 5.1 (standard deviation) years at surgery. All patients but one had a magnetic resonance imaging (MRI)-visible lesion. Resections were parietal in 40%, occipital in 32%, and parietooccipital in 28% cases; 24% patients additionally underwent a resection of the posterior border of the temporal lobe. Etiology included focal cortical dysplasia in 44%, benign tumors (dysembryoplastic neuroepithelial tumor, ganglioglioma, angiocentric glioma, and pilocystic astrocytoma) in 32%, peri- or postnatal ischemic lesions in 16%, and tuberous sclerosis in 8% cases. At last follow-up (mean 8 years, range 1.5-18 years), 60% patients remained seizure-free (Engel class I): 30% had discontinued and 20% had reduced antiepileptic drugs. Most seizure recurrences (71%) occurred within the first 6 months, and only three patients presented with seizures ≥2 years after surgery. Independent predictors of seizure recurrence included left-sided as well as parietal epileptogenic zones and resections. Longer epilepsy duration to surgery was identified as the only modifiable independent predictor of seizure recurrence. Our study demonstrates that posterior cortex epilepsy surgery is highly effective in terms of lasting seizure control and antiepileptic drug cessation in selected pediatric candidates. Most importantly, our data supports the early consideration of surgical intervention in children and adolescents with refractory posterior cortex epilepsy. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  2. Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

    International Nuclear Information System (INIS)

    Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun

    2007-01-01

    We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging

  3. Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging.

  4. Reduced spontaneous neuronal activity in the insular cortex and thalamus in healthy adults with insomnia symptoms.

    Science.gov (United States)

    Liu, Chun-Hong; Liu, Cun-Zhi; Zhang, Jihui; Yuan, Zhen; Tang, Li-Rong; Tie, Chang-Le; Fan, Jin; Liu, Qing-Quan

    2016-10-01

    Poor sleep and insomnia have been recognized to be strongly correlated with the development of depression. The exploration of the basic mechanism of sleep disturbance could provide the basis for improved understanding and treatment of insomnia and prevention of depression. In this study, 31 subjects with insomnia symptoms as measured by the Hamilton Rating Scale for Depression (HAMD-17) and 71 age- and gender-matched subjects without insomnia symptoms were recruited to participate in a clinical trial. Using resting-state functional magnetic resonance imaging (rs-fMRI), we examined the alterations in spontaneous brain activity between the two groups. Correlations between the fractional amplitude of low frequency fluctuations (fALFF) and clinical measurements (e.g., insomnia severity and Hamilton Depression Rating Scale [HAMD] scores) were also tested in all subjects. Compared to healthy participants without insomnia symptoms, participants with insomnia symptoms showed a decreased fALFF in the left ventral anterior insula, bilateral posterior insula, left thalamus, and pons but an increased fALFF in the bilateral middle occipital gyrus and right precentral gyrus. More specifically, a significant, negative correlation of fALFF in the left thalamus with early morning awakening scores and HAMD scores in the overall sample was identified. These results suggest that insomnia symptoms are associated with altered spontaneous activity in the brain regions of several important functional networks, including the insular cortex of the salience and the thalamus of the hyperarousal network. The altered fALFF in the left thalamus supports the "hyperarousal theory" of insomnia symptoms, which could serve as a biomarker for insomnia. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Executive Semantic Processing Is Underpinned by a Large-scale Neural Network: Revealing the Contribution of Left Prefrontal, Posterior Temporal, and Parietal Cortex to Controlled Retrieval and Selection Using TMS

    Science.gov (United States)

    Whitney, Carin; Kirk, Marie; O'Sullivan, Jamie; Ralph, Matthew A. Lambon; Jefferies, Elizabeth

    2012-01-01

    To understand the meanings of words and objects, we need to have knowledge about these items themselves plus executive mechanisms that compute and manipulate semantic information in a task-appropriate way. The neural basis for semantic control remains controversial. Neuroimaging studies have focused on the role of the left inferior frontal gyrus…

  6. The vertical occipital fasciculus: A century of controversy resolved by in vivo measurements

    Science.gov (United States)

    Yeatman, Jason D.; Weiner, Kevin S.; Pestilli, Franco; Rokem, Ariel; Mezer, Aviv; Wandell, Brian A.

    2014-01-01

    The vertical occipital fasciculus (VOF) is the only major fiber bundle connecting dorsolateral and ventrolateral visual cortex. Only a handful of studies have examined the anatomy of the VOF or its role in cognition in the living human brain. Here, we trace the contentious history of the VOF, beginning with its original discovery in monkey by Wernicke (1881) and in human by Obersteiner (1888), to its disappearance from the literature, and recent reemergence a century later. We introduce an algorithm to identify the VOF in vivo using diffusion-weighted imaging and tractography, and show that the VOF can be found in every hemisphere (n = 74). Quantitative T1 measurements demonstrate that tissue properties, such as myelination, in the VOF differ from neighboring white-matter tracts. The terminations of the VOF are in consistent positions relative to cortical folding patterns in the dorsal and ventral visual streams. Recent findings demonstrate that these same anatomical locations also mark cytoarchitectonic and functional transitions in dorsal and ventral visual cortex. We conclude that the VOF is likely to serve a unique role in the communication of signals between regions on the ventral surface that are important for the perception of visual categories (e.g., words, faces, bodies, etc.) and regions on the dorsal surface involved in the control of eye movements, attention, and motion perception. PMID:25404310

  7. Language Networks in Anophthalmia: Maintained Hierarchy of Processing in "Visual" Cortex

    Science.gov (United States)

    Watkins, Kate E.; Cowey, Alan; Alexander, Iona; Filippini, Nicola; Kennedy, James M.; Smith, Stephen M.; Ragge, Nicola; Bridge, Holly

    2012-01-01

    Imaging studies in blind subjects have consistently shown that sensory and cognitive tasks evoke activity in the occipital cortex, which is normally visual. The precise areas involved and degree of activation are dependent upon the cause and age of onset of blindness. Here, we investigated the cortical language network at rest and during an…

  8. Aphasia following left thalamic hemorrhage

    International Nuclear Information System (INIS)

    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro.

    1984-01-01

    We reported 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months), and described language disorders examined by Western Aphasia Battery (WAB) and measured cerebral blood flow by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in watershed area that involved the territory between posterior cerebral and middle cerebral arteries in the left temporooccipital region in addition to low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, whose score of repetition (8.4) was higher than that of comprehension (7.4), emission CT showed slight low flow area at the temporo-occipital region similarly as the case with transcortical sensory aphasia. In another case with anomic aphasia, scored 9 on both fluensy and comprehension subtests and 10 on repetition, there was wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. On the other hand, in all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus. (J.P.N.)

  9. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

    Directory of Open Access Journals (Sweden)

    Honda Manabu

    2006-12-01

    Full Text Available Abstract Background It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1, is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D shapes on Mah-Jong tiles (Mah-Jong experts. Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. Results When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. Conclusion The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  10. False Memories for Shape Activate the Lateral Occipital Complex

    Science.gov (United States)

    Karanian, Jessica M.; Slotnick, Scott D.

    2017-01-01

    Previous functional magnetic resonance imaging evidence has shown that false memories arise from higher-level conscious processing regions rather than lower-level sensory processing regions. In the present study, we assessed whether the lateral occipital complex (LOC)--a lower-level conscious shape processing region--was associated with false…

  11. Grooves on the occipital lobe of Indian brains.

    Science.gov (United States)

    Bisaria, K K

    1984-01-01

    The existence of a groove on the occipital lobe formed by the dural venous sinus or ridge has only rarely been described in the past. As observed in this study such grooves are either unilateral or bilateral and their incidence is very high in Indian brains. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6490537

  12. Grooves on the occipital lobe of Indian brains.

    OpenAIRE

    Bisaria, K K

    1984-01-01

    The existence of a groove on the occipital lobe formed by the dural venous sinus or ridge has only rarely been described in the past. As observed in this study such grooves are either unilateral or bilateral and their incidence is very high in Indian brains.

  13. Occipital condyle fracture and ligament injury: imaging by CT

    International Nuclear Information System (INIS)

    Bloom, A.I.; Neeman, Z.; Floman, Y.; Gomori, J.; Bar-Ziv, J.

    1996-01-01

    The true incidence of fracture of the occipital condyles is unknown. It may be associated with instability at the craniocervical joint. CT is the modality of choice for the demonstration of these fractures, but its use for imaging of the associated ligament injury has not been reported. In order to demonstrate normal anatomy, occipital condyle fracture and ligament injury, and to estimate the incidence of this lesion, 21 children and young adults with high-energy blunt craniocervical injury were examined prospectively. Thin-slice, axial, contiguous, CT was performed from the base of C2 to above the foramen magnum. Bone and soft tissue windows and coronal, sagittal, and curvilinear 2D reconstructions were performed. Five occipital condyle fractures were identified in four patients (19 %), with demonstration of alar ligament injury in two cases and local hematoma in one. In four, artifacts or rotation precluded assessment of ligaments. In all remaining cases normal bone and ligament anatomy was demonstrated. Fracture of the occipital condyles following craniocervical injury is not uncommon in children and young adults. Normal bone and ligament anatomy and pathology can be safely and clearly demonstrated in seriously injured patients and others using this CT technique. Increased awareness of this entity and a low threshold for performing CT should avoid the potentially serious consequences of a missed diagnosis. (orig.). With 8 figs., 2 tabs

  14. Post-mortem CT evaluation of atlanto-occipital dissociation.

    Science.gov (United States)

    Madadin, Mohammed; Samaranayake, Ravindra Priyalal; O'Donnell, Chris; Cordner, Stephen

    2017-02-01

    Atlanto-occipital dissociation injury is an important injury in forensic pathology practice. Radiological diagnosis of atlanto-occipital dissociation clinically is assessed by direct measurement of occipito-vertebral skeletal relationships. Different measurements may be used to diagnose atlanto-occipital dissociation, including the basion-dens interval (BDI) and basion-axial interval (BAI). It is not known whether the normal ante-mortem measurements of BDI and BAI described in the literature are applicable to post-mortem CT images of the occipito-cervical junction (OCJ) or whether these measurements could be affected by early post-mortem changes. This study aims to compare post-mortem BDI and BAI measurements with ante-mortem values. Post-mortem CT scans of the cervical spines of 100 deceased adults were reviewed, and the BDI and BAI were measured. Different parameters were recorded in each case. The results from this study suggest that there are no effects of post-mortem changes on the measurement of BAI as relied upon clinically. There appear to be some effects of fully established rigor mortis on BDI measurement, shortening it. This may have consequences for the post mortem diagnosis of atlanto-occipital dissociation. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  15. A case study of occipital outgrowth: a rare suboccipital abnormality.

    Science.gov (United States)

    Mushkin, A Y; Gubin, A V; Ulrich, E V; Snischuk, V P

    2016-05-01

    To describe the clinical and radiological characteristics of uncommon upper cervical spine abnormality in children. Clinical and diagnostic characteristics of three patients aged 6-12 years with a similar uncommon type of occipital anomaly are described. The patients were admitted in 2007, 2009, and 2014, respectively. All patients were clinically and radiologically examined. In each case the massive, additional unilateral outgrowth of the occipital bone (os occipitale) was visualized. The signs and symptoms included torticollis, acute brain ischemia, and limited head motion. Two of the three patients underwent surgical treatment: an occipital-cervical fusion was performed in the first patient, and the outgrowth was removed in the second patient. After 1 year of follow-up the results were estimated as good for both patients, with better functional outcome for the second patient. The parents of the third patient did not consent for the surgical treatment. The unique features of this abnormality distinguish it from previous descriptions of the manifestation of pro-atlas, atlas, or atlanto-occipital synostosis. The presented abnormality had different manifestation of various severity in each case, from torticollis to acute vascular disorder. Clinical case series. IV.

  16. Etiology and Treatment Modalities of Occipital Artery Aneurysms.

    Science.gov (United States)

    Chaudhry, Nauman S; Gaynor, Brandon G; Hussain, Shahrose; Dernbach, Paul D; Aziz-Sultan, Mohammad A

    2017-06-01

    Aneurysms of the external carotid artery represent approximately 2% of cervical carotid aneurysms, with the majority being traumatic pseudoaneurysms. Given the paucity of literature available for guidance, the diagnosis, treatment, and follow-up of such lesions are completely individualized. We report an 83-year-old woman with an 8-week history of headache in the occipital region, transient episode of gait disturbance, and pulsatile tinnitus on the right. She had no history of trauma, surgery, autoimmune disease, or infection. Physical examination revealed a pulsatile mass tender to palpation in the right occipital scalp. The mass was surgically excised, and histopathological diagnosis of a true aneurysm was made. Postoperatively, the patient's symptoms resolved; however, 1 month after the procedure, she developed occipital neuralgia, which was successfully treated with a percutaneous nerve block. To the best of our knowledge, this is the second reported case of a true aneurysm of the occipital artery in a patient with no history of trauma. The clinical examination, diagnosis, and treatment are discussed and the literature is reviewed for previously reported cases. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A comparison of occipital and temporal lobe epilepsies.

    Science.gov (United States)

    Appel, S; Sharan, A D; Tracy, J I; Evans, J; Sperling, M R

    2015-10-01

    Differentiating between occipital lobe epilepsy (OLE) and temporal lobe epilepsy (TLE) is often challenging. This retrospective case-control study compares OLE to TLE and explores markers that suggest the diagnosis of OLE. We queried the Jefferson Epilepsy Center surgery database for patients who underwent a resection that involved the occipital lobe. For each patient with OLE, three sequential case-control patients with TLE were matched. Demographic characteristics, symptoms, electrophysiological findings, imaging findings, and surgical outcome were compared. Nineteen patients with OLE and 57 patients with TLE were included in the study. Visual symptoms were unique to patients with OLE (8/19) and were not reported by patients with TLE (P Occipital interictal spikes (IIS) were found only in one-third of the patients with OLE (6/19) and in no patients with TLE (P lobe were found in five of 19 patients with OLE vs one of 57 patients with TLE (P = 0.003). IIS involved more than one lobe of the brain in most patients with OLE (11/19) but only in nine of 57 the TLE group. (P = 0.0003) Multilobar resection was needed in most patients with OLE (15/19), typically including the temporal lobe, but in only one of the patients with TLE (P Occipital lobe epilepsy is difficult to identify and may masquerade as temporal lobe epilepsy. Visual symptoms and occipital findings in the EEG suggest the diagnosis of OLE, but absence of these features, does not exclude the diagnosis. When posterior temporal EEG findings or multilobar involvement occurs, the diagnosis of OLE should be considered. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. CT-based morphometric analysis of the occipital condyle: focus on occipital condyle screw insertion.

    Science.gov (United States)

    Zhou, Jinsong; Espinoza Orías, Alejandro A; Kang, Xia; He, Jade; Zhang, Zhihai; Inoue, Nozomu; An, Howard S

    2016-11-01

    OBJECTIVE The segmental occipital condyle screw (OCS) is an alternative fixation technique in occipitocervical fusion. A thorough morphological study of the occipital condyle (OC) is critical for OCS placement. The authors set out to introduce a more precise CT-based method for morphometric analysis of the OC as it pertains to the placement of the segmental OCS, and they describe a novel preoperative simulation method for screw placement. Two new clinically relevant parameters, the height available for the OCS and the warning depth, are proposed. METHODS CT data sets from 27 fresh-frozen human cadaveric occipitocervical spines were used. All measurements were performed using a commercially available 3D reconstruction software package. The length, width, and sagittal angle of the condyle were measured in the axial plane at the base of the OC. The height of the OC and the height available for the segmental OCS were measured in the reconstructed oblique sagittal plane, fitting the ideal trajectory of the OCS recommended in the literature. The placement of a 3.5-mm-diameter screw that had the longest length of bicortical purchase was simulated into the OC in the oblique sagittal plane, with the screw path not being blocked by the occiput and not violating the hypoglossal canal cranially or the atlantooccipital joint caudally. The length of the simulated screw was recorded. The warning depth was measured as the shortest distance from the entry point of the screw to the posterior border of the hypoglossal canal. RESULTS The mean length and width of the OC were found to be larger in males: 22.2 ± 1.7 mm and 12.1 ± 1.0 mm, respectively, overall (p < 0.0001 for both). The mean sagittal angle was 28.0° ± 4.9°. The height available for the OCS was significantly less than the height of the OC (6.2 ± 1.3 mm vs 9.4 ± 1.5 mm, p < 0.0001). The mean screw length (19.3 ± 1.9 mm) also presented significant sex-related differences: male greater than female (p = 0.0002). The

  19. Tracing short connections of the temporo-parieto-occipital region in the human brain using diffusion spectrum imaging and fiber dissection.

    Science.gov (United States)

    Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yunjie; Wang, Yibao

    2016-09-01

    The temporo-parieto-occipital (TPO) junction plays a unique role in human high-level neurological functions. Long-range fibers from and to this area have been described in detail but little is known about short TPO tracts mediating local connectivity. In this study, we performed high angular diffusion spectrum imaging (DSI) analyses to visualize the short TPO connections in the human brain. Fiber tracking was conducted on a subject-specific approach (10 subjects) and a template of 90 subjects (NTU-90 Atlas). Three tracts were identified: posterior segment of the superior longitudinal fasciculus (SLF-V), connecting the posterior part of the middle and inferior temporal gyri with the angular gyrus and supramarginal gyrus, vertical occipital fasciculus (VOF), connecting the inferior parietal with the lower temporal and occipital lobe, and a novel temporo-parietal (TP) connection, interconnecting the inferior temporal gyrus, middle temporal gyrus and fusiform gyrus, and inferior occipital lobe with the superior parietal lobe. These studies were complemented by fiber dissection techniques. It is the first study that demonstrated the trajectory and connectivity of the VOF using fiber dissection, as well as displayed the spatial relationship of the SLF-V with the cortex and the adjacent fiber bundles on one dissecting hemisphere. By providing a more accurate and detailed description of the local connectivity of the TPO junction, our findings help to develop new insights into its functional role in the human brain. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Occipital epilepsy versus progressive myoclonic epilepsy in a patient with continuous occipital spikes and photosensitivity in electroencephalogram: A case report.

    Science.gov (United States)

    Lv, Yudan; Zhang, Nan; Liu, Chang; Shi, Mingchao; Sun, Li

    2018-04-01

    Progressive myoclonic epilepsy (PME) is rare epilepsy syndrome. Although EEG is a useful neurophysiological technique in the evaluation of epilepsy, few EEG abnormalities have been described in PME. So, how to use EEG hints to establish the suspected diagnosis of PME as soon as possible should be addressed. We presented a case with refractory myoclonic seizures, and progressive neurological deterioration, diagnosed as PME and neuronal ceroid lipofuscinosis disease by gene testing. The patient manifested with a significant regression in her speech ability and motor balance. The mini-mental state examination showed poor scores of 15/30. The magnetic resonance imaging showed diffused atrophy. Her EEG showed slow background with continuous occipital small spikes and photosensitivity. The following genetic testing with mutation in CLN6 confirmed the diagnosis and excluded the occipital epilepsy. Our case showed rare manifestations and special EEG features of PME, which may be confused with occipital epilepsy or photosensitive epilepsy. Thus, if the continuous occipital spikes and photosensitivity were presented in a patient with refractory seizures and developmental regression, PME should be considered.

  1. Assessment of Brain Damage and Plasticity in the Visual System Due to Early Occipital Lesion: Comparison of FDG-PET with Diffusion MRI Tractography

    Science.gov (United States)

    Jeong, Jeong-won; Tiwari, Vijay N.; Shin, Joseph; Chugani, Harry T.; Juhász, Csaba

    2015-01-01

    Purpose To determine the relation between glucose metabolic changes of the primary visual cortex, structural abnormalities of the corresponding visual tracts, and visual symptoms in children with Sturge-Weber syndrome (SWS). Materials and Methods In 10 children with unilateral SWS (ages 1.5–5.5 years), a region-of-interest analysis was applied in the bilateral medial occipital cortex on positron emission tomography (PET) and used to track diffusion-weighted imaging (DWI) streamlines corresponding to the central visual pathway. Normalized streamline volumes of individual SWS patients were compared with values from age-matched control groups as well as correlated with normalized glucose uptakes and visual field deficit. Results Lower glucose uptake and lower corresponding streamline volumes were detected in the affected occipital lobe in 9/10 patients, as compared to the contralateral side. Seven of these 9 patients had visual field deficit and normal or decreased streamline volumes on the unaffected side. The two other children had no visual symptoms and showed high contralateral visual streamline volumes. There was a positive correlation between the normalized ratios on DWI and PET, indicating that lower glucose metabolism was associated with lower streamline volume in the affected hemisphere (R = 0.70, P = 0.024). Conclusion We demonstrated that 18F-flurodeoxyglucose (FDG)-PET combined with DWI tractography can detect both brain damage on the side of the lesion and contralateral plasticity in children with early occipital lesions. PMID:24391057

  2. The human cerebral cortex is neither one nor many: Neuronal distribution reveals two quantitatively different zones in the grey matter, three in the white matter, and explains local variations in cortical folding

    Directory of Open Access Journals (Sweden)

    Pedro F. M. Ribeiro

    2013-09-01

    Full Text Available The human prefrontal cortex has been considered different in several aspects and relatively enlarged compared to the rest of the cortical areas. Here we determine whether the white and gray matter of the prefrontal portion of the human cerebral cortex have similar or different cellular compositions relative to the rest of the cortical regions by applying the Isotropic Fractionator to analyze the distribution of neurons along the entire anteroposterior axis of the cortex, and its relationship with the degree of gyrification, number of neurons under the cortical surface, and other parameters. The prefrontal region shares with the remainder of the cerebral cortex (except for occipital cortex the same relationship between cortical volume and number of neurons. In contrast, both occipital and prefrontal areas vary from other cortical areas in their connectivity through the white matter, with a systematic reduction of cortical connectivity through the white matter and an increase of the mean axon caliber along the anteroposterior axis. These two parameters explain local differences in the distribution of neurons underneath the cortical surface. We also show that local variations in cortical folding are neither a function of local numbers of neurons nor of cortical thickness, but correlate with properties of the white matter, and are best explained by the folding of the white matter surface. Our results suggest that the human cerebral cortex is divided in two zones (occipital and non-occipital that differ in how neurons distributed across their grey matter volume and in three zones (prefrontal, occipital, and non-occipital that differ in how neurons are connected through the white matter. Thus, the human prefrontal cortex has the largest fraction of neuronal connectivity through the white matter and the smallest average axonal caliber in the white matter within the cortex, although its neuronal composition fits the pattern found for other, non-occipital

  3. Occipital deep white matter hyperintensity as seen by MRI, 1

    International Nuclear Information System (INIS)

    Miyazaki, Masahito; Hashimoto, Toshiaki; Tayama, Masanobu; Kuroda, Yasuhiro

    1992-01-01

    Magnetic resonance imaging was performed in 270 patients with various neurologic complaints (1-15Y) with a 0.5 tesla superconducting imaging system using a field echo T1-weighted sequence and spin echo T2-weighted and PD-weighted sequences. Twenty-seven of them had deep white matter hyperintensity (DWMH) in the occipital lobe on T2-weighted images. The frequency of mild DWMH differed in different age groups, suggesting that mild DWMH may result from delayed myelination in the central nervous system. However, the frequency of severe DWMH, which was revealed as isointense relative to cerebrospinal fluid, did not differ in different age groups and it was significantly more common in severely retarded patients. Classification of DWMH based on the signal intensity is valuable to distinguish white matter abnormalities in the occipital lobe from delayed myelination in the same site. (author)

  4. Giant cell reparative granuloma of the occipital bone

    International Nuclear Information System (INIS)

    Santos-Briz, A.; Ricoy, J.R.; Martinez-Tello, F.J.; Lobato, R.D.; Ramos, A.; Millan, J.M.

    2003-01-01

    Giant cell reparative granuloma (GCRG) is a non-neoplastic fibrous lesion with unevenly distributed multinucleated giant cells, areas of osseous metaplasia and hemorrhage. The small bones of the hands and feet are the most common sites, followed by the vertebral bodies and craniofacial bones. In the craniofacial bones GCRG has been reported in the temporal bone, in the frontal bone and paranasal sinus. However, to the best of our knowledge no case has been reported in the occipital bone. We report on the imaging findings and pathological features of a GCRG of the occipital bone and discuss the differential diagnosis of this entity in this particular location, especially with giant cell tumor because of the therapeutic and prognostic implications. (orig.)

  5. Occipital MEG Activity in the Early Time Range (

    DEFF Research Database (Denmark)

    Andersen, Lau M; Pedersen, Michael N; Sandberg, Kristian

    2015-01-01

    . Recent studies have suggested that the late component may not be uniquely related to perceptual consciousness, but also to sensory expectations, task associations, and selective attention. We conducted a magnetoencephalographic study; using multivariate analysis, we compared classification accuracies....... These results are the first of its kind where the predictive values of the 2 components are quantitatively compared, and they provide further evidence for the primary importance of occipital sources in realizing perceptual consciousness. The results have important consequences for current theories of perceptual...

  6. Mirror Focus in a Patient with Intractable Occipital Lobe Epilepsy

    OpenAIRE

    Kim, Jiyoung; Shin, Hae kyung; Hwang, Kyoung Jin; Choi, Su Jung; Joo, Eun Yeon; Hong, Seung Bong; Hong, Seung Chul; Seo, Dae-Won

    2014-01-01

    Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy....

  7. Prenatal Diagnosis of Tectocerebellar Dysraphia with Occipital Encephalocele

    Science.gov (United States)

    Sanhal, Cem Y; Tokmak, Aytekin; Müftüoglu, Kamil H; Danisman, Nuri

    2015-01-01

    Tectocerebellar dysraphia (TCD) is an extremely rare disorder and comprises the congenital abnormalities including occipital encephalocele, aplasia and/or hypoplasia of cerebellar vermis and deformity of tectum. Only few reported cases of this entity are there in the literature. However, the diagnosis in each of the previous cases had been made after birth. We herein describe the first reported case of prenatal diagnosis for TCD in a Turkish woman. PMID:26816952

  8. Places in the Brain: Bridging Layout and Object Geometry in Scene-Selective Cortex.

    Science.gov (United States)

    Dillon, Moira R; Persichetti, Andrew S; Spelke, Elizabeth S; Dilks, Daniel D

    2017-06-13

    Diverse animal species primarily rely on sense (left-right) and egocentric distance (proximal-distal) when navigating the environment. Recent neuroimaging studies with human adults show that this information is represented in 2 scene-selective cortical regions-the occipital place area (OPA) and retrosplenial complex (RSC)-but not in a third scene-selective region-the parahippocampal place area (PPA). What geometric properties, then, does the PPA represent, and what is its role in scene processing? Here we hypothesize that the PPA represents relative length and angle, the geometric properties classically associated with object recognition, but only in the context of large extended surfaces that compose the layout of a scene. Using functional magnetic resonance imaging adaptation, we found that the PPA is indeed sensitive to relative length and angle changes in pictures of scenes, but not pictures of objects that reliably elicited responses to the same geometric changes in object-selective cortical regions. Moreover, we found that the OPA is also sensitive to such changes, while the RSC is tolerant to such changes. Thus, the geometric information typically associated with object recognition is also used during some aspects of scene processing. These findings provide evidence that scene-selective cortex differentially represents the geometric properties guiding navigation versus scene categorization. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Nonlinear responses within the medial prefrontal cortex reveal when specific implicit information influences economic decision making.

    Science.gov (United States)

    Deppe, Michael; Schwindt, Wolfram; Kugel, Harald; Plassmann, Hilke; Kenning, Peter

    2005-04-01

    The authors used functional magnetic resonance imaging (fMRI) to investigate how individual economic decisions are influenced by implicit memory contributions. Twenty-two participants were asked to make binary decisions between different brands of sensorily nearly undistinguishable consumer goods. Changes of brain activity comparing decisions in the presence or absence of a specific target brand were detected by fMRI. Only when the tar get brand was the participant's favorite one did the authors find reduced activation in the dorsolateral prefrontal, posterior parietal, and occipital cortices and the left premotor area (Brodmann areas [BA] 9, 46, 7/19, and 6). Simultaneously, activity was increased in the inferior precuneus and posterior cingulate (BA 7), right superior frontal gyrus (BA 10), right supramarginal gyrus (BA 40), and, most pronounced, in the ventromedial prefrontal cortex (BA 10). For products mainly distinguishable by brand information, the authors revealed a nonlinear winner-take-all effect for a participant's favorite brand characterized, on one hand, by reduced activation in brain areas associated with working memory and reasoning and, on the other hand, increased activation in areas involved in processing of emotions and self-reflections during decision making.

  10. Metabolic changes in occipital lobe epilepsy with automatisms

    Directory of Open Access Journals (Sweden)

    Chong H Wong

    2014-07-01

    Full Text Available Purpose: Some studies suggest that the pattern of glucose hypometabolism relates not only to the ictal-onset zone, but also reflects seizure propagation. We investigated metabolic changes in patients with occipital lobe epilepsy (OLE that may reflect propagation of ictal discharge during seizures with automatisms.Methods: Fifteen patients who had undergone epilepsy surgery for intractable OLE and had undergone interictal Fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET between 1994 and 2004 were divided into two groups (with and without automatisms during seizure. Significant regions of hypometabolism were identified by comparing 18F-FDG-PET results from each group with 16 healthy controls by using Statistical Parametric Mapping (SPM 2.Key Findings: Significant hypometabolism was confined largely to the epileptogenic occipital lobe in the patient group without automatisms. In patients with automatisms, glucose hypometabolism extended from the epileptogenic occipital lobe into the ipsilateral temporal lobe.Significance: We identified a distinctive hypometabolic pattern that was specific for OLE patients with automatisms during a seizure. This finding supports the postulate that seizure propagation is a cause of glucose hypometabolism beyond the region of seizure onset.

  11. Metabolic changes in occipital lobe epilepsy with automatisms.

    Science.gov (United States)

    Wong, Chong H; Mohamed, Armin; Wen, Lingfeng; Eberl, Stefan; Somerville, Ernest; Fulham, Michael; Bleasel, Andrew F

    2014-01-01

    Some studies suggest that the pattern of glucose hypometabolism relates not only to the ictal-onset zone but also reflects seizure propagation. We investigated metabolic changes in patients with occipital lobe epilepsy (OLE) that may reflect propagation of ictal discharge during seizures with automatisms. Fifteen patients who had undergone epilepsy surgery for intractable OLE and had undergone interictal Fluorine-18-fluorodeoxyglucose positron-emission tomography ((18)F-FDG-PET) between 1994 and 2004 were divided into two groups (with and without automatisms during seizure). Significant regions of hypometabolism were identified by comparing (18)F-FDG-PET results from each group with 16 healthy controls by using statistical parametric mapping. Significant hypometabolism was confined largely to the epileptogenic occipital lobe in the patient group without automatisms. In patients with automatisms, glucose hypometabolism extended from the epileptogenic occipital lobe into the ipsilateral temporal lobe. We identified a distinctive hypometabolic pattern that was specific for OLE patients with automatisms during a seizure. This finding supports the postulate that seizure propagation is a cause of glucose hypometabolism beyond the region of seizure onset.

  12. Progressive skin necrosis of a huge occipital encephalocele

    Science.gov (United States)

    Andarabi, Yasir; Nejat, Farideh; El-Khashab, Mostafa

    2008-01-01

    Objects: Progressive skin necrosis of giant occipital encephalocoele is an extremely rare complication found in neonates. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocoele showing progressive necrosis during the first day of his life. Methods: A newborn baby was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the last hours of the first day of his life, the sac started becoming ulcerated accompanied with a rapid color change in the skin, gradually turning darker and then black. The neonate was taken up for urgent excision and repair of the encephalocele. Two years after the operation, he appears to be well-developed without any neurological problems. Conclusion: Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocoele may be another predisposing factor. In view of the risk of ulceration and subsequent infection, urgent surgery of the necrotizing encephalocele is suggested. PMID:19753210

  13. Progressive skin necrosis of a huge occipital encephalocele

    Directory of Open Access Journals (Sweden)

    Andarabi Yasir

    2008-01-01

    Full Text Available Objects: Progressive skin necrosis of giant occipital encephalocoele is an extremely rare complication found in neonates. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocoele showing progressive necrosis during the first day of his life. Methods: A newborn baby was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the last hours of the first day of his life, the sac started becoming ulcerated accompanied with a rapid color change in the skin, gradually turning darker and then black. The neonate was taken up for urgent excision and repair of the encephalocele. Two years after the operation, he appears to be well-developed without any neurological problems. Conclusion: Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocoele may be another predisposing factor. In view of the risk of ulceration and subsequent infection, urgent surgery of the necrotizing encephalocele is suggested.

  14. Use of occipital nerve block in emergency department treatment of status migrainosus: A case report.

    Science.gov (United States)

    Yanuck, Justin; Nelson, Ariana; Jen, Maxwell

    2018-03-21

    Migraine headaches make up a significant proportion of emergency department visits. There are multiple pharmacologic treatment modalities for migraine abortive therapy; however, these treatments are rarely targeted to the precise area of pain and thus elicit multiple systemic effects. It has been well established in the anesthesia pain literature that occipital nerve blocks can provide not only immediate pain relief from occipital migraines, but can also result in a long-term resolution of occipital migraines. In this case report, we present how an occipital nerve block in the emergency department resulted in immediate and long-lasting resolution of a patient's occipital migraine. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Traumatic atlanto-occipital dissociation presenting as locked-in syndrome.

    Science.gov (United States)

    Desai, Rupen; Kinon, Merritt D; Loriaux, Daniel B; Bagley, Carlos A

    2015-12-01

    We present an unusual presentation of unstable atlanto-occipital dissociation as locked-in syndrome. Traumatic atlanto-occipital dissociation is a severe injury that accounts for 15-20% of all fatal cervical spinal injuries. A disruption occurs between the tectorial ligaments connecting the occipital condyle to the superior articulating facets of the atlas, resulting in anterior, longitudinal, or posterior translation, and it may be associated with Type III odontoid fractures. Furthermore, the dissociation may be complete (atlanto-occipital dislocation) or incomplete (atlanto-occipital subluxation), with neurologic findings ranging from normal to complete quadriplegia with respiratory compromise. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Pathways of seizure propagation from the temporal to the occipital lobe.

    Science.gov (United States)

    Jacobs, Julia; Dubeau, François; Olivier, André; Andermann, Frederick

    2008-12-01

    Propagation of ictal epileptic discharges influences the clinical appearance of seizures. Fast propagation from the occipital to temporal lobe has been well described, but until now the reverse direction of spread has not been emphasized. We describe two patients who experienced ictal propagation from temporal to occipital regions. One case presented with amaurosis during a seizure with temporal onset and temporal-occipital spread. In the second, temporal-occipital spread was documented during a seizure, which continued in the occipital lobe for six minutes. Depth electrode studies suggested the temporal ictal onset of seizures in both patients. Propagation from temporal to occipital lobe structures must be considered in the assessment of patients who have seizures with both temporal and occipital features. The propagation may have predictive value for their surgical outcome. The underlying anatomical structure might be the inferior longitudinal fasciculus.

  17. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen

    2011-01-01

    Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude...

  18. Effective Connectivity from Early Visual Cortex to Posterior Occipitotemporal Face Areas Supports Face Selectivity and Predicts Developmental Prosopagnosia.

    Science.gov (United States)

    Lohse, Michael; Garrido, Lucia; Driver, Jon; Dolan, Raymond J; Duchaine, Bradley C; Furl, Nicholas

    2016-03-30

    Face processing is mediated by interactions between functional areas in the occipital and temporal lobe, and the fusiform face area (FFA) and anterior temporal lobe play key roles in the recognition of facial identity. Individuals with developmental prosopagnosia (DP), a lifelong face recognition impairment, have been shown to have structural and functional neuronal alterations in these areas. The present study investigated how face selectivity is generated in participants with normal face processing, and how functional abnormalities associated with DP, arise as a function of network connectivity. Using functional magnetic resonance imaging and dynamic causal modeling, we examined effective connectivity in normal participants by assessing network models that include early visual cortex (EVC) and face-selective areas and then investigated the integrity of this connectivity in participants with DP. Results showed that a feedforward architecture from EVC to the occipital face area, EVC to FFA, and EVC to posterior superior temporal sulcus (pSTS) best explained how face selectivity arises in both controls and participants with DP. In this architecture, the DP group showed reduced connection strengths on feedforward connections carrying face information from EVC to FFA and EVC to pSTS. These altered network dynamics in DP contribute to the diminished face selectivity in the posterior occipitotemporal areas affected in DP. These findings suggest a novel view on the relevance of feedforward projection from EVC to posterior occipitotemporal face areas in generating cortical face selectivity and differences in face recognition ability. Areas of the human brain showing enhanced activation to faces compared to other objects or places have been extensively studied. However, the factors leading to this face selectively have remained mostly unknown. We show that effective connectivity from early visual cortex to posterior occipitotemporal face areas gives rise to face

  19. Biomechanical and morphometric evaluation of occipital condyle for occipitocervical segmental fixation

    International Nuclear Information System (INIS)

    Hong, Jae-Taek; Takigaya, Tomoyuki; Sugisaki, Keizo; Orias, A.A.E.; Inoue, Nozomu; An, H.S.

    2011-01-01

    Two recent novel techniques of occipital fixation are the occipitoatlantal (C0-C1) transarticular screw technique and the direct occipital condyle screw technique. The present study evaluated and compared the biomechanical stability of the direct occipital condyle screw and C0-C1 transarticular screw with the established method for craniocervical spine fixation using the midline occipital keel screw and C1 lateral mass screw. Morphometric evaluation of the occipital condyle and the hypoglossal canal was performed to avoid hypoglossal nerve injury during the screw placement. Thirteen recently frozen cadaveric specimens were used. The occipital condyle anatomy and the hypoglossal canal dimension were measured using reconstructed computed tomography images. Insertion torque and pullout strength were evaluated to compare the midline occipital keel screw, C0-C1 transarticular screw, C1 lateral mass screw, and direct occipital condyle screw. The dimensions of the occipital condyle allow use of a 3.5 or 4.0-mm diameter screw. Mean pullout strength was 1619.6 N for the midline occipital keel screw, 870.7 N for the C0-C1 transarticular screw, 707.0 N for the C1 lateral mass screw, and 431.7 N for the direct occipital condyle screw. Mean insertion torque was 0.55 Nm for the midline occipital keel screw, 0.32 Nm for the C0-C1 transarticular screw, 0.14 Nm for the C1 lateral mass screw, and 0.11 Nm for the direct occipital condyle screw. The condylar anatomy allows direct insertion of the occipital condyle screw and C0-C1 transarticular screw. These techniques are suitable options for the treatment of craniovertebral junction instabilities in selected patients. (author)

  20. Occipital lobe and posterior cingulate perfusion in the prediction of dementia with Lewy body pathology in a clinical sample.

    Science.gov (United States)

    Prosser, Angus M J; Tossici-Bolt, Livia; Kipps, Christopher M

    2017-12-01

    The aim of this study was to investigate the diagnostic value of occipital lobe and posterior cingulate perfusion in predicting dopamine transporter imaging outcome using a quantitative measure of analysis. In total, 99 patients with cognitive complaints who had undergone both technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (Tc-HMPAO SPECT) and I ioflupane (I-FP-CIT also called DaTSCAN) imaging in a dementia diagnostic center were analyzed. Measures of perfusion were calculated from HMPAO SPECT images for the medial and lateral occipital lobe, the posterior cingulate cortex, precuneus and cuneus regions of interest using statistical parametric mapping 8. DaTSCAN images were quantified and specific binding ratios were calculated independent from HMPAO SPECT results. Statistical parametric mapping and tests of associations between perfusion and I-FP-CIT imaging were completed. Regions of interest on HMPAO yielded poor predictive values when used independently to predict I-FP-CIT status; however, the combination of normal posterior cingulate perfusion with medial and lateral occipital hypoperfusion was associated significantly with I-FP-CIT status, χ (1, N=99)=9.72, P=0.002. This combination also yielded a high positive likelihood ratio and specificity (11.1, 98%). Sensitivity was, however, low (22%). No significant perfusion differences were found when abnormal and normal I-FP-CIT groups were compared directly using voxel-based morphometry (Poccipital hypoperfusion with preserved posterior cingulate gyrus perfusion is highly specific for individuals with a positive I-FP-CIT scan in a clinical sample where diagnostic doubt exists. This regional combination, however, lacks sensitivity; therefore, absence of the sign cannot be used to rule out dementia with Lewy bodies. A positive finding provides strong evidence to rule in dementia with Lewy bodies.

  1. Evidence for intact local connectivity but disrupted regional function in the occipital lobe in children and adolescents with schizophrenia.

    Science.gov (United States)

    White, Tonya; Moeller, Steen; Schmidt, Marcus; Pardo, Jose V; Olman, Cheryl

    2012-08-01

    It has long been known that specific visual frequencies result in greater blood flow to the striate cortex. These peaks are thought to reflect synchrony of local neuronal firing that is reflective of local cortical networks. Since disrupted neural connectivity is a possible etiology for schizophrenia, our goal was to investigate whether localized connectivity, as measured by aberrant synchrony, is abnormal in children and adolescents with schizophrenia. Subjects included 25 children and adolescents with schizophrenia and 39 controls matched for age and gender. Subjects were scanned on a Siemens 3 Tesla Trio scanner while observing flashing checkerboard presented at either 1, 4, 8, or 12 Hz. Image processing included both a standard GLM model and a Fourier transform analysis. Patients had significantly smaller volume of activation in the occipital lobe compared to controls. There were no differences in the integral or percent signal change of the hemodynamic response function for each of the four frequencies. Occipital activation was stable during development between childhood and late adolescence. Finally, both patients and controls demonstrated an increased response between 4 and 8 Hz consistent with synchrony or entrainment in the neuronal response. Children and adolescents with schizophrenia had a significantly lower volume of activation in the occipital lobe in response to the flashing checkerboard task. However, features of intact local connectivity in patients, such as the hemodynamic response function and maximal response at 8 Hz, were normal. These results are consistent with abnormalities in regional connectivity with preserved local connectivity in early-onset schizophrenia. Copyright © 2011 Wiley Periodicals, Inc.

  2. The cerebral cortex of Albert Einstein: a description and preliminary analysis of unpublished photographs

    Science.gov (United States)

    Lepore, Frederick E.; Noe, Adrianne

    2013-01-01

    Upon his death in 1955, Albert Einstein’s brain was removed, fixed and photographed from multiple angles. It was then sectioned into 240 blocks, and histological slides were prepared. At the time, a roadmap was drawn that illustrates the location within the brain of each block and its associated slides. Here we describe the external gross neuroanatomy of Einstein’s entire cerebral cortex from 14 recently discovered photographs, most of which were taken from unconventional angles. Two of the photographs reveal sulcal patterns of the medial surfaces of the hemispheres, and another shows the neuroanatomy of the right (exposed) insula. Most of Einstein’s sulci are identified, and sulcal patterns in various parts of the brain are compared with those of 85 human brains that have been described in the literature. To the extent currently possible, unusual features of Einstein’s brain are tentatively interpreted in light of what is known about the evolution of higher cognitive processes in humans. As an aid to future investigators, these (and other) features are correlated with blocks on the roadmap (and therefore histological slides). Einstein’s brain has an extraordinary prefrontal cortex, which may have contributed to the neurological substrates for some of his remarkable cognitive abilities. The primary somatosensory and motor cortices near the regions that typically represent face and tongue are greatly expanded in the left hemisphere. Einstein’s parietal lobes are also unusual and may have provided some of the neurological underpinnings for his visuospatial and mathematical skills, as others have hypothesized. Einstein’s brain has typical frontal and occipital shape asymmetries (petalias) and grossly asymmetrical inferior and superior parietal lobules. Contrary to the literature, Einstein’s brain is not spherical, does not lack parietal opercula and has non-confluent Sylvian and inferior postcentral sulci. PMID:23161163

  3. The cerebral cortex of Albert Einstein: a description and preliminary analysis of unpublished photographs.

    Science.gov (United States)

    Falk, Dean; Lepore, Frederick E; Noe, Adrianne

    2013-04-01

    Upon his death in 1955, Albert Einstein's brain was removed, fixed and photographed from multiple angles. It was then sectioned into 240 blocks, and histological slides were prepared. At the time, a roadmap was drawn that illustrates the location within the brain of each block and its associated slides. Here we describe the external gross neuroanatomy of Einstein's entire cerebral cortex from 14 recently discovered photographs, most of which were taken from unconventional angles. Two of the photographs reveal sulcal patterns of the medial surfaces of the hemispheres, and another shows the neuroanatomy of the right (exposed) insula. Most of Einstein's sulci are identified, and sulcal patterns in various parts of the brain are compared with those of 85 human brains that have been described in the literature. To the extent currently possible, unusual features of Einstein's brain are tentatively interpreted in light of what is known about the evolution of higher cognitive processes in humans. As an aid to future investigators, these (and other) features are correlated with blocks on the roadmap (and therefore histological slides). Einstein's brain has an extraordinary prefrontal cortex, which may have contributed to the neurological substrates for some of his remarkable cognitive abilities. The primary somatosensory and motor cortices near the regions that typically represent face and tongue are greatly expanded in the left hemisphere. Einstein's parietal lobes are also unusual and may have provided some of the neurological underpinnings for his visuospatial and mathematical skills, as others have hypothesized. Einstein's brain has typical frontal and occipital shape asymmetries (petalias) and grossly asymmetrical inferior and superior parietal lobules. Contrary to the literature, Einstein's brain is not spherical, does not lack parietal opercula and has non-confluent Sylvian and inferior postcentral sulci.

  4. Unawareness of deficits in Alzheimer's disease: role of the cingulate cortex.

    Science.gov (United States)

    Amanzio, Martina; Torta, Diana M E; Sacco, Katiuscia; Cauda, Franco; D'Agata, Federico; Duca, Sergio; Leotta, Daniela; Palermo, Sara; Geminiani, Giuliano C

    2011-04-01

    Unawareness of deficits is a symptom of Alzheimer's disease that can be observed even in the early stages of the disease. The frontal hypoperfusion associated with reduced awareness of deficits has led to suggestions of the existence of a hypofunctioning prefrontal pathway involving the right dorsolateral prefrontal cortex, inferior parietal lobe, anterior cingulate gyri and limbic structures. Since this network plays an important role in response inhibition competence and patients with Alzheimer's disease who are unaware of their deficits exhibit impaired performance in response inhibition tasks, we predicted a relationship between unawareness of deficits and cingulate hypofunctionality. We tested this hypothesis in a sample of 29 patients with Alzheimer's disease (15 aware and 14 unaware of their disturbances), rating unawareness according to the Awareness of Deficit Questionnaire-Dementia scale. The cognitive domain was investigated by means of a wide battery including tests on executive functioning, memory and language. Neuropsychiatric aspects were investigated using batteries on behavioural mood changes, such as apathy and disinhibition. Cingulate functionality was assessed with functional magnetic resonance imaging, while patients performed a go/no-go task. In accordance with our hypotheses, unaware patients showed reduced task-sensitive activity in the right anterior cingulate area (Brodmann area 24) and in the rostral prefrontal cortex (Brodmann area 10). Unaware patients also showed reduced activity in the right post-central gyrus (Brodmann area 2), in the associative cortical areas such as the right parietotemporal-occipital junction (Brodmann area 39) and the left temporal gyrus (Brodmann areas 21 and 38), in the striatum and in the cerebellum. These findings suggest that the unawareness of deficits in early Alzheimer's disease is associated with reduced functional recruitment of the cingulofrontal and parietotemporal regions. Furthermore, in line with

  5. Visual cortex entrains to sign language.

    Science.gov (United States)

    Brookshire, Geoffrey; Lu, Jenny; Nusbaum, Howard C; Goldin-Meadow, Susan; Casasanto, Daniel

    2017-06-13

    Despite immense variability across languages, people can learn to understand any human language, spoken or signed. What neural mechanisms allow people to comprehend language across sensory modalities? When people listen to speech, electrophysiological oscillations in auditory cortex entrain to slow ([Formula: see text]8 Hz) fluctuations in the acoustic envelope. Entrainment to the speech envelope may reflect mechanisms specialized for auditory perception. Alternatively, flexible entrainment may be a general-purpose cortical mechanism that optimizes sensitivity to rhythmic information regardless of modality. Here, we test these proposals by examining cortical coherence to visual information in sign language. First, we develop a metric to quantify visual change over time. We find quasiperiodic fluctuations in sign language, characterized by lower frequencies than fluctuations in speech. Next, we test for entrainment of neural oscillations to visual change in sign language, using electroencephalography (EEG) in fluent speakers of American Sign Language (ASL) as they watch videos in ASL. We find significant cortical entrainment to visual oscillations in sign language sign is strongest over occipital and parietal cortex, in contrast to speech, where coherence is strongest over the auditory cortex. Nonsigners also show coherence to sign language, but entrainment at frontal sites is reduced relative to fluent signers. These results demonstrate that flexible cortical entrainment to language does not depend on neural processes that are specific to auditory speech perception. Low-frequency oscillatory entrainment may reflect a general cortical mechanism that maximizes sensitivity to informational peaks in time-varying signals.

  6. Occipital plagiocephaly: deformation or lambdoid synostosis? I. morphometric analysis and results of unilateral lambdoid craniectomy

    International Nuclear Information System (INIS)

    Dias, M.S.; Klein, D.M.; Backstrom, J.W.

    1997-01-01

    Between 1987 and 1992, 30 infants aged 1.4-13 months (mean 7.3 months) underwent unilateral lambdoid strip craniectomy at the Children's Hospital of Buffalo for occipital plagiocephaly. Males outnumbered females (22:8) and right-sided occipital flattening was significantly more common than left-sided flattening (25:5). The deformity was noticed at an average age of 3.2 months; 16% of the infants had an asymmetry at birth. Positional preferences (a distinct tendency to lie preferentially on the back, in most cases with the head turned to the ipsilateral side) were described in 79% of infants for whom this information was available, and torticollis was present in 10%. Pre-and post-operative CT scans were analyzed using several morphometric measurements. Asymmetries were measured between the flattened and contralateral sides, both posteriorly and anteriorly, using a translucent grid placed over the CT slice showing maximum asymmetry. The average maximum asymmetry between the flattened and contralateral sides was 24% posteriorly and 16% anteriorly. Significant improvements were seen postoperatively, with both anterior and posterior asymmetries improving by an average of one third (p < 0.05). However, when compared with CT scans from a control group of infants without synostosis, the operated group showed persistent and significant asymmetries postoperatively. The morphometric measurements described allow an objective and reproducible means of assessing the results of various treatments for this disorders. The improvements following unilateral lambdoid craniectomy are difficult to interpret in isolation; we suggest that future efforts be directed toward similarly assessing the results of both nonoperative treatments such as positional changes and molding helmets, and more aggressive surgical treatments that have been advocated for this disorders. (authors)

  7. Expression of cellular prion protein in the frontal and occipital lobe in Alzheimer's disease, diffuse Lewy body disease, and in normal brain: an immunohistochemical study.

    Science.gov (United States)

    Rezaie, Payam; Pontikis, Charlie C; Hudson, Lance; Cairns, Nigel J; Lantos, Peter L

    2005-08-01

    Cellular prion protein (PrP(c)) is a glycoprotein expressed at low to moderate levels within the nervous system. Recent studies suggest that PrP(c) may possess neuroprotective functions and that its expression is upregulated in certain neurodegenerative disorders. We investigated whether PrP(c) expression is altered in the frontal and occipital cortex in two well-characterized neurodegenerative disorders--Alzheimer's disease (AD) and diffuse Lewy body disease (DLBD)--compared with that in normal human brain using immunohistochemistry and computerized image analysis. The distribution of PrP(c) was further tested for correlation with glial reactivity. We found that PrP(c) was localized mainly in the gray matter (predominantly in neurons) and expressed at higher levels within the occipital cortex in the normal human brain. Image analysis revealed no significant variability in PrP(c) expression between DLBD and control cases. However, blood vessels within the white matter of DLBD cases showed immunoreactivity to PrP(c). By contrast, this protein was differentially expressed in the frontal and occipital cortex of AD cases; it was markedly overexpressed in the former and significantly reduced in the latter. Epitope specificity of antibodies appeared important when detecting PrP(c). The distribution of PrP(c) did not correlate with glial immunoreactivity. In conclusion, this study supports the proposal that regional changes in expression of PrP(c) may occur in certain neurodegenerative disorders such as AD, but not in other disorders such as DLBD.

  8. Rapid recurrence and bilateral lungs, multiple bone metastasis of malignant solitary fibrous tumor of the right occipital lobe: report of a case and review.

    Science.gov (United States)

    Wu, Zhengrong; Yang, Hongjun; Weng, Desheng; Ding, Yanqing

    2015-07-09

    Intracranial malignant solitary fibrous tumor (MSFT) is extremely rare. The authors report a case of MSFT of the right occipital lobe with a rapid recurrence and bilateral lung, multiple bone metastasis. The patient was a 25-year-old male presenting with headache, nausea and visual disturbances without obvious cause. Three times right-side occipital craniotomies were performed and two times postoperative conformal radiotherapy were administered within one year. 4 months after the third time of right-side occipital craniotomy, the patient felt right chest pain and neck pain. Positron emission tomography/computed tomography (PET/CT) showed tumor recurrence of the right occipital lobe and bilateral lung metastasis, multiple bone metastasis including: vertebrae, libs, the left iliac wing, sacrum, the right ischium and upper parts of both femurs. Ultrasound guided puncture biopsy of left-side back of the neck and CT guided puncture biopsy of the third lumbar vertebra were performed. General sample showed grayish white or grayish red with irregular shape. Histopathologically, the tumor was composed of areas of alternating hypercellularity and hypocellularity with spindle-shaped cells, which arranged as fascicular, storiform pattern or patternless pattern, with intervening irregular eosinophilic collagen bundles. Some areas showed hemangiopericytoma-like perivascular pattern and perivascular hyalinization. Tumor cells were pleomorphic with mitotic counts of more than 4 per 10 high power fields and showed coagulative necrosis. Immunohistochemically, tumor cells were diffusely positive for vimentin and CD99, focal positive for CD34, bcl-2 and Actin. Ki-67 labelling index was more than 40%. The final pathological diagnosis was MSFT of the right occipital lobe, metastatic MSFT of left-side back of the neck and the third lumbar vertebra. The MSFT of the right occipital lobe with recurrence and bilateral lung, multiple bone metastasis is extremely rare. Although intracranial

  9. Benign childhood epilepsy with occipital paroxysms: neuropsychological findings.

    Science.gov (United States)

    Germanò, Eva; Gagliano, Antonella; Magazù, Angela; Sferro, Caterina; Calarese, Tiziana; Mannarino, Erminia; Calamoneri, Filippo

    2005-05-01

    Benign childhood epilepsy with occipital paroxysms is classified among childhood benign partial epilepsies. The absence of neurological and neuropsychological deficits has long been considered as a prerequisite for a diagnosis of benign childhood partial epilepsy. Much evidence has been reported in literature in the latest years suggesting a neuropsychological impairment in this type of epilepsy, particularly in the type with Rolandic paroxysms. The present work examines the neuropsychological profiles of a sample of subjects affected by the early-onset benign childhood occipital seizures (EBOS) described by Panayotopulos. The patient group included 22 children (14 males and 8 females; mean age 10.1+/-3.3 years) diagnosed as having EBOS. The patients were examined with a set of tests investigating neuropsychological functions: memory, attention, perceptive, motor, linguistic and academic (reading, writing, arithmetic) abilities. The same instruments have been given to a homogeneous control group as regards sex, age, level of education and socio-economic background. None of the subjects affected by EBOS showed intellectual deficit (mean IQ in Wechsler Full Scale 91.7; S.D. 8.9). Results show a widespread cognitive dysfunction in the context of a focal epileptogenic process in EBOS. In particular, children with EBOS show a significant occurrence of specific learning disabilities (SLD) and other subtle neuropsychological deficits. We found selective dysfunctions relating to perceptive-visual attentional ability (pmemory abilities (psupports the hypothesis that epilepsy itself plays a role in the development of neuropsychological impairment. Supported by other studies that have documented subtle neuropsychological deficits in benign partial epilepsy, we stress the importance of reconsidering its supposed "cognitive benignity", particularly in occipital types.

  10. Epilepsy classification and additional definitions in occipital lobe epilepsy.

    Science.gov (United States)

    Yilmaz, Kutluhan; Karatoprak, Elif Yüksel

    2015-09-01

    To evaluate epileptic children with occipital lobe epilepsy (OLE) in the light of the characteristics of Panayiotopoulos syndrome and late-onset occipital lobe epilepsy of Gastaut (OLE-G). Patients were categorized into six groups: primary OLE with autonomic symptoms (Panayiotopoulos syndrome), primary OLE with visual symptoms (OLE-G), secondary OLE with autonomic symptoms (P-type sOLE), secondary OLE with visual symptoms (G-type sOLE), and non-categorized primary OLE and non-categorized secondary OLE according to characteristic ictal symptoms of both Panayiotopoulos syndrome and OLE-G, as well as aetiology (primary or secondary). Patients were compared with regards to seizure symptoms, aetiology, cranial imaging, EEG, treatment and outcome. Of 108 patients with OLE (6.4±3.9 years of age), 60 patients constituted primary groups (32 with Panayiotopoulos syndrome, 11 with OLE-G, and 17 with non-categorized primary OLE); the other 48 patients constituted secondary groups (eight with P-type sOLE, three with G-type sOLE, and 37 with non-categorized sOLE). Epileptiform activity was restricted to the occipital area in half of the patients. Generalized epileptiform activity was observed in three patients, including a patient with Panayiotopoulos syndrome (PS). Only one patient had refractory epilepsy in the primary groups while such patients made up 29% in the secondary groups. In OLE, typical autonomic or visual ictal symptoms of Panayiotopoulos syndrome and OLE-G do not necessarily indicate primary (i.e. genetic or idiopathic) aetiology. Moreover, primary OLE may not present with these symptoms. Since there are many patients with OLE who do not exhibit the characteristics of Panayiotopoulos syndrome or OLE-G, additional definitions and terminology appear to be necessary to differentiate between such patients in both clinical practice and studies.

  11. Assessing the Effect of Early Visual Cortex Transcranial Magnetic Stimulation on Working Memory Consolidation.

    Science.gov (United States)

    van Lamsweerde, Amanda E; Johnson, Jeffrey S

    2017-07-01

    Maintaining visual working memory (VWM) representations recruits a network of brain regions, including the frontal, posterior parietal, and occipital cortices; however, it is unclear to what extent the occipital cortex is engaged in VWM after sensory encoding is completed. Noninvasive brain stimulation data show that stimulation of this region can affect working memory (WM) during the early consolidation time period, but it remains unclear whether it does so by influencing the number of items that are stored or their precision. In this study, we investigated whether single-pulse transcranial magnetic stimulation (spTMS) to the occipital cortex during VWM consolidation affects the quantity or quality of VWM representations. In three experiments, we disrupted VWM consolidation with either a visual mask or spTMS to retinotopic early visual cortex. We found robust masking effects on the quantity of VWM representations up to 200 msec poststimulus offset and smaller, more variable effects on WM quality. Similarly, spTMS decreased the quantity of VWM representations, but only when it was applied immediately following stimulus offset. Like visual masks, spTMS also produced small and variable effects on WM precision. The disruptive effects of both masks and TMS were greatly reduced or entirely absent within 200 msec of stimulus offset. However, there was a reduction in swap rate across all time intervals, which may indicate a sustained role of the early visual cortex in maintaining spatial information.

  12. Presentation of moyamoya disease with occipital hemorrhage: a case report

    Directory of Open Access Journals (Sweden)

    Serkan Demir

    2012-12-01

    Full Text Available Moyamoya disease is a cerebrovascular disease which is characterized with stenosis and occlusions at the distal part of internal carotid artery and at the proximal part of anterior and middle cerebral arteries. It rarely causes temporary or recurrent hemiparesis due to intracranial hemorrhage while symptoms like headache, convulsion, nystagmus, aphasia and ataxia may also occur. In this paper, we present a case of Moyamoya disease which was diagnosed with a 23 year old female patient who was admitted to our emergency department with headache, nausea and vomiting complaints and whose radiological findings showed occipital lobe hemorrhage.

  13. Conceito anátomo-fisiológico do lobo occipital Functional anatomy of the occipital lobe

    Directory of Open Access Journals (Sweden)

    M. Caetano de Barros

    1972-03-01

    Full Text Available Apenas do ponto de vista estritamente anatômico o lobo occipital pode ser delimitado com relativa facilidade. Aparentemente constitui uma unidade morfológica, séde de estruturas basicamente relacionados com a percepção visual, aí entendidos também certos mecanismos integrativos óculo-motores que, em última análise, não são senão componentes dêste complexo fenômeno perceptivo. Depois de revistos alguns detalhes da anatomia convencional do lobo occipital (limites, área cortical estriada, peri-estriada e para-estriada é feita uma tentativa, à base de estudo da literatura, no sentido de indicar as principais conexões destas áreas (radiações ópticas, feixes de associação, fibras de projeção e fibras comissurais com diferentes estruturas do sistema nervoso central. A vascularização do lobo occipital é revisada com o auxílio de preparações anátomo-radiológicas seriadas e seletivas de diferentes troncos arteriais, nas quais se constatam intercomunicações entre os setores "terminais" dos sistemas das artérias cerebral posterior, média e anterior. Algumas variações morfológicas dos cornos occipitais são também postas em evidência com recursos de técnicas anátomo-radiológicas. Todavia, dados puramente anatômicos não são suficientes para compreensão das funções psico-fisiológicas do lobo occipital que pode ser conceituado como parte de um sistema perceptivo — o sistema óptico — altamente complexo, funcionando integradamente com múltiplos sectores do sistema nervoso e envolvendo diferentes mecanismos. Muito provàvelmente êste sistema, à maneira de muitos outros sistemas biológicos, está composto de vários circuitos mutuamente conjugados agindo sob o princípio de servo-mecanismos, devendo sua ação ser encaixada dentro do conceito das "totalidades" (Gestalten, cuja funcionalidade não deriva da soma dos seus componentes, mas da relação funcional que estes mantém entre sí para a atua

  14. Spheno-Occipital Synchondrosis Fusion Correlates with Cervical Vertebrae Maturation.

    Directory of Open Access Journals (Sweden)

    María José Fernández-Pérez

    Full Text Available The aim of this study was to determine the relationship between the closure stage of the spheno-occipital synchondrosis and the maturational stage of the cervical vertebrae (CVM in growing and young adult subjects using cone beam computed tomography (CBCT. CBCT images with an extended field of view obtained from 315 participants (148 females and 167 males; mean age 15.6 ±7.3 years; range 6 to 23 years were analyzed. The fusion status of the synchondrosis was determined using a five-stage scoring system; the vertebral maturational status was evaluated using a six-stage stratification (CVM method. Ordinal regression was used to study the ability of the synchondrosis stage to predict the vertebral maturation stage. Vertebrae and synchondrosis had a strong significant correlation (r = 0.89 that essential was similar for females (r = 0.88 and males (r = 0.89. CVM stage could be accurately predicted from synchondrosis stage by ordinal regression models. Prediction equations of the vertebral stage using synchondrosis stage, sex and biological age as predictors were developed. Thus this investigation demonstrated that the stage of spheno-occipital synchondrosis, as determined in CBCT images, is a reasonable indicator of growth maturation.

  15. Segregation and persistence of form in the lateral occipital complex.

    Science.gov (United States)

    Ferber, Susanne; Humphrey, G Keith; Vilis, Tutis

    2005-01-01

    While the lateral occipital complex (LOC) has been shown to be implicated in object recognition, it is unclear whether this brain area is responsive to low-level stimulus-driven features or high-level representational processes. We used scrambled shape-from-motion displays to disambiguate the presence of contours from figure-ground segregation and to measure the strength of the binding process for shapes without contours. We found persisting brain activation in the LOC for scrambled displays after the motion stopped indicating that this brain area subserves and maintains figure-ground segregation processes, a low-level function in the object processing hierarchy. In our second experiment, we found that the figure-ground segregation process has some form of spatial constancy indicating top-down influences. The persisting activation after the motion stops suggests an intermediate role in object recognition processes for this brain area and might provide further evidence for the idea that the lateral occipital complex subserves mnemonic functions mediating between iconic and short-term memory.

  16. Spheno-Occipital Synchondrosis Fusion Correlates with Cervical Vertebrae Maturation.

    Science.gov (United States)

    Fernández-Pérez, María José; Alarcón, José Antonio; McNamara, James A; Velasco-Torres, Miguel; Benavides, Erika; Galindo-Moreno, Pablo; Catena, Andrés

    2016-01-01

    The aim of this study was to determine the relationship between the closure stage of the spheno-occipital synchondrosis and the maturational stage of the cervical vertebrae (CVM) in growing and young adult subjects using cone beam computed tomography (CBCT). CBCT images with an extended field of view obtained from 315 participants (148 females and 167 males; mean age 15.6 ±7.3 years; range 6 to 23 years) were analyzed. The fusion status of the synchondrosis was determined using a five-stage scoring system; the vertebral maturational status was evaluated using a six-stage stratification (CVM method). Ordinal regression was used to study the ability of the synchondrosis stage to predict the vertebral maturation stage. Vertebrae and synchondrosis had a strong significant correlation (r = 0.89) that essential was similar for females (r = 0.88) and males (r = 0.89). CVM stage could be accurately predicted from synchondrosis stage by ordinal regression models. Prediction equations of the vertebral stage using synchondrosis stage, sex and biological age as predictors were developed. Thus this investigation demonstrated that the stage of spheno-occipital synchondrosis, as determined in CBCT images, is a reasonable indicator of growth maturation.

  17. Early 'visual' cortex activation correlates with superior verbal memory performance in the blind.

    Science.gov (United States)

    Amedi, Amir; Raz, Noa; Pianka, Pazit; Malach, Rafael; Zohary, Ehud

    2003-07-01

    The visual cortex may be more modifiable than previously considered. Using functional magnetic resonance imaging (fMRI) in ten congenitally blind human participants, we found robust occipital activation during a verbal-memory task (in the absence of any sensory input), as well as during verb generation and Braille reading. We also found evidence for reorganization and specialization of the occipital cortex, along the anterior-posterior axis. Whereas anterior regions showed preference for Braille, posterior regions (including V1) showed preference for verbal-memory and verb generation (which both require memory of verbal material). No such occipital activation was found in sighted subjects. This difference between the groups was mirrored by superior performance of the blind in various verbal-memory tasks. Moreover, the magnitude of V1 activation during the verbal-memory condition was highly correlated with the blind individual's abilities in a variety of verbal-memory tests, suggesting that the additional occipital activation may have a functional role.

  18. Difference in the functional connectivity of the dorsolateral prefrontal cortex between smokers with nicotine dependence and individuals with internet gaming disorder.

    Science.gov (United States)

    Ge, Xin; Sun, Yawen; Han, Xu; Wang, Yao; Ding, Weina; Cao, Mengqiu; Du, Yasong; Xu, Jianrong; Zhou, Yan

    2017-07-27

    It has been reported that internet gaming disorder (IGD) and smokers with nicotine dependence (SND) share clinical characteristics, such as over-engagement despite negative consequences and cravings. This study is to investigate the alterations in the resting-state functional connectivity (rsFC) of the dorsolateral prefrontal cortex (DLPFC) observed in SND and IGD. In this study, 27 IGD, 29 SND, and 33 healthy controls (HC) underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scan. DLPFC connectivity was determined in all participates by investigating the synchronized low-frequency fMRI signal fluctuations using a temporal seed-based correlation method. Compared with the HC group, the IGD and SND groups showed decreased rsFC with DLPFC in the right insula and left inferior frontal gyrus with DLPFC. Compared with SND group, the IGD subjects exhibited increased rsFC in the left inferior temporal gyrus and right inferior orbital frontal gyrus and decreased rsFC in the right middle occipital gyrus, supramarginal gyrus, and cuneus with DLPFC. Our results confirmed that SND and IGD share similar neural mechanisms related to craving and impulsive inhibitions. The significant difference in rsFC with DLPFC between the IGD and SND subjects may be attributed to the visual and auditory stimulation generated by long-term internet gaming.

  19. 5HT{sub 2} receptors in cerebral cortex of migraineurs studied using PET and {sup 18}F-fluorosetoperoene

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    Chabriat, H.; Tehindrazanarivelo, A.; Vera, P.; Samson, Y.; Pappata, S.; Boullais, N.; Bousser, M.G. [Hospital Saint Antoine, Paris (France)

    1995-04-01

    Since the brain 5HT{sub 2} might be implicated in migraine pathogenesis, the authors have used positron emission tomography and {sup 18}F-fluorosetoperone, a 5HT{sub 2} specific radioligand, to investigate in vivo the cortical 5HT{sub 2} receptors in migraine subjects. Nine migraineurs who had either migraine with and without aura or only migraine without aura were studied between attacks. 12 unmedicated healthy subjects of similar mean age were used as controls. Brain radioactivity was measured after {sup 18}F-setoperone IV injection for 90 min. A decrease of the regional specific distribution volumes (SDV) of the ligand was observed both in migraineurs and in controls. The age adjusted group means of SDV did not differ between patients and controls for the whole and for the right or left frontal, temporal, parietal and occipital cortex. These results suggest that cortical 5HT{sub 2} receptors may be unaltered between attacks in migraine sufferers. 30 refs., 4 figs., 2 tabs.

  20. [A painful occipital mass revealing a posterior encephalocele].

    Science.gov (United States)

    Meunier, Sarah; Michalak, Sophie; Chaigneau, Julien; Mercier, Philippe; Rousseau, Audrey

    2014-08-01

    Encephalocele is a congenital malformation caused by a neural tube defect during embryonic development. We report a case of posterior encephalocele in a 7-month-old infant with a painful occipital mass known since birth. Pathological examination of the mass showed different mature tissues derived from the brain and its coverings (e.g., neuroglia, ependymal canals and clusters of meningothelial cells). A diagnosis of encephalocele was made. The different forms of neural tube defect will be briefly discussed, especially the "aborted" forms (e.g., non-specific midline mass lesion or angioma) that the pathologist may encounter in his/her daily practice. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  1. Occipital Alpha and Gamma Oscillations Support Complementary Mechanisms for Processing Stimulus Value Associations.

    Science.gov (United States)

    Marshall, Tom R; den Boer, Sebastiaan; Cools, Roshan; Jensen, Ole; Fallon, Sean James; Zumer, Johanna M

    2018-01-01

    Selective attention is reflected neurally in changes in the power of posterior neural oscillations in the alpha (8-12 Hz) and gamma (40-100 Hz) bands. Although a neural mechanism that allows relevant information to be selectively processed has its advantages, it may lead to lucrative or dangerous information going unnoticed. Neural systems are also in place for processing rewarding and punishing information. Here, we examine the interaction between selective attention (left vs. right) and stimulus's learned value associations (neutral, punished, or rewarded) and how they compete for control of posterior neural oscillations. We found that both attention and stimulus-value associations influenced neural oscillations. Whereas selective attention had comparable effects on alpha and gamma oscillations, value associations had dissociable effects on these neural markers of attention. Salient targets (associated with positive and negative outcomes) hijacked changes in alpha power-increasing hemispheric alpha lateralization when salient targets were attended, decreasing it when they were being ignored. In contrast, hemispheric gamma-band lateralization was specifically abolished by negative distractors. Source analysis indicated occipital generators of both attentional and value effects. Thus, posterior cortical oscillations support both the ability to selectively attend while at the same time retaining the ability to remain sensitive to valuable features in the environment. Moreover, the versatility of our attentional system to respond separately to salient from merely positively valued stimuli appears to be carried out by separate neural processes reflected in different frequency bands.

  2. High resolution anatomical and quantitative MRI of the entire human occipital lobe ex vivo at 9.4T.

    Science.gov (United States)

    Sengupta, S; Fritz, F J; Harms, R L; Hildebrand, S; Tse, D H Y; Poser, B A; Goebel, R; Roebroeck, A

    2018-03-01

    Several magnetic resonance imaging (MRI) contrasts are sensitive to myelin content in gray matter in vivo which has ignited ambitions of MRI-based in vivo cortical histology. Ultra-high field (UHF) MRI, at fields of 7T and beyond, is crucial to provide the resolution and contrast needed to sample contrasts over the depth of the cortex and get closer to layer resolved imaging. Ex vivo MRI of human post mortem samples is an important stepping stone to investigate MRI contrast in the cortex, validate it against histology techniques applied in situ to the same tissue, and investigate the resolutions needed to translate ex vivo findings to in vivo UHF MRI. Here, we investigate key technology to extend such UHF studies to large human brain samples while maintaining high resolution, which allows investigation of the layered architecture of several cortical areas over their entire 3D extent and their complete borders where architecture changes. A 16 channel cylindrical phased array radiofrequency (RF) receive coil was constructed to image a large post mortem occipital lobe sample (~80×80×80mm 3 ) in a wide-bore 9.4T human scanner with the aim of achieving high-resolution anatomical and quantitative MR images. Compared with a human head coil at 9.4T, the maximum Signal-to-Noise ratio (SNR) was increased by a factor of about five in the peripheral cortex. Although the transmit profile with a circularly polarized transmit mode at 9.4T is relatively inhomogeneous over the large sample, this challenge was successfully resolved with parallel transmit using the kT-points method. Using this setup, we achieved 60μm anatomical images for the entire occipital lobe showing increased spatial definition of cortical details compared to lower resolutions. In addition, we were able to achieve sufficient control over SNR, B 0 and B 1 homogeneity and multi-contrast sampling to perform quantitative T 2 * mapping over the same volume at 200μm. Markov Chain Monte Carlo sampling provided

  3. Overlooked metastatic lesions of the occipital condyle: a missed case treasure trove.

    Science.gov (United States)

    Loevner, L A; Yousem, D M

    1997-01-01

    Radiologic images obtained in nine patients with known primary cancer and occipital or head and neck pain were retrospectively reviewed after having been initially interpreted as normal. Imaging studies included head computed tomography (CT) in five cases, brain magnetic resonance (MR) imaging in six cases, cervical spine CT and MR imaging in five cases, radiography in two cases, and scintigraphy in two cases. This reevaluation demonstrated lesions of the occipital condyles in all patients. Seven patients had unilateral occipital condyle masses, and two patients had bilateral condyle lesions. Lesions were found to either involve only the occipital condyle (n = 4), extend to the adjacent occipital bone (n = 3), or extend to the ipsilateral clivus (n = 2). Misinterpretation of radiologic examinations resulted in an average delay in diagnosis of 10 weeks from the onset of symptoms to definitive therapy (irradiation). It is important to evaluate the occipital condyles in all patients with occipital pain, especially those with cancer. Neoplastic disease involving the occipital condyles is not common; however, it is frequently missed at imaging. Careful review of unenhanced sagittal and axial T1-weighted MR images and of the inferior sections from axial head CT studies will make it possible to avoid this potential pitfall.

  4. Bi-phasic activation of the primary motor cortex by pain and its relation to pain-evoked potentials - an exploratory study.

    Science.gov (United States)

    Kisler, Lee-Bareket; Weissman-Fogel, Irit; Sinai, Alon; Sprecher, Elliot; Chistyakov, Andrei V; Shamay-Tsoory, Simone; Moscovitz, Nadav; Granovsky, Yelena

    2017-06-15

    The primary motor cortex (M1) is a known target for brain stimulation aimed at pain alleviation in chronic pain patients, yet the mechanisms through which analgesia occurs, and the exact pain-motor interrelations are not fully understood. We used noxious contact heat evoked potentials (CHEPs) and cortical source analysis to further explore the relevance of M1 in pain processing. Twenty-four healthy young females received brief noxious heat stimuli to their left non-dominant volar forearm, simultaneously with CHEPs recordings. Thereafter, the pain-evoked activity of M1 and a control area in the occipital cortex (OC) was analyzed and estimated using sLORETA (standardized low-resolution brain electromagnetic tomography). This analysis revealed two phases of M1 pain-evoked activation (phase 1: the peak at 261.5±25.7ms; phase 2: the peak at 381.3±28.3ms). Canonical correlations revealed that M1, but not the OC, was the main factor contributing to the relation with the CHEPs components. In detail, the activity magnitude of M1 first and second phases was related to the N2 and P2 amplitude, respectively. The latency of the second phase was associated with both N2 and P2 latencies. In relation to pain, the latency of M1's first activity phase was positively correlated with pain ratings, suggesting pain interference to synchronized activity in M1. Our results confirm the established relevance of the primary motor cortex to pain processing. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Disrupted functional connectivity of the anterior cingulate cortex in cirrhotic patients without overt hepatic encephalopathy: a resting state fMRI study.

    Directory of Open Access Journals (Sweden)

    Long Jiang Zhang

    Full Text Available BACKGROUND: To evaluate the changes of functional connectivity of the anterior cingulate cortex (ACC in patients with cirrhosis without overt hepatic encephalopathy (HE using resting state functional MRI. METHODOLOGY/PRINCIPAL FINDINGS: Participants included 67 cirrhotic patients (27 minimal hepatic encephalopathy (MHE and 40 cirrhotic patients without MHE (non-HE, and 40 age- and gender- matched healthy controls. rsfMRI were performed on 3 Telsa scanners. The pregenual ACC resting-state networks (RSNs were characterized by using a standard seed-based whole-brain correlation method and compared between cirrhotic patients and healthy controls. Pearson correlation analysis was performed between the ACC RSNs and venous blood ammonia levels, neuropsychological tests (number connection test type A [NCT-A] and digit symbol test [DST] scores in cirrhotic patients. All thresholds were set at P<0.05, with false discovery rate corrected. Compared with controls, non-HE and MHE patients showed significantly decreased functional connectivity in the bilateral ACC, bilateral middle frontal cortex (MFC, bilateral middle cingulate cortex (MCC, bilateral superior temporal gyri (STG/middle temporal gyri (MTG, bilateral thalami, bilateral putamen and bilateral insula, and increased functional connectivity of bilateral precuneus and left temporo-occipital lobe and bilateral lingual gyri. Compared with non-HE patients, MHE showed the decreased functional connectivity of right MCC, bilateral STG/MTG and right putamen. This indicates decreased ACC functional connectivity predominated with the increasing severity of HE. NCT-A scores negatively correlated with ACC functional connectivity in the bilateral MCC, right temporal lobe, and DST scores positively correlated with functional connectivity in the bilateral ACC and the right putamen. No correlation was found between venous blood ammonia levels and functional connectivity in ACC in cirrhotic patients. CONCLUSIONS

  6. Brain mapping of epileptic activity in a case of idiopathic occipital lobe epilepsy (Panayiotopoulos syndrome).

    Science.gov (United States)

    Leal, Alberto J R; Nunes, Sofia; Martins, António; Secca, Mário Forjaz; Jordão, Constança

    2007-06-01

    The Panayiotopoulos type of occipital lobe epilepsy has generated great interest, but the particular brain areas involved in the peculiar seizure manifestations have not been established. We studied a patient with the syndrome, using high-resolution EEG and simultaneous EEG and functional magnetic resonance imaging (fMRI). Resolution of the scalp EEG was improved using a realistic spline Laplacian algorithm, and produced a complex distribution of current sinks and sources over the occipital lobe. The spike-related blood oxygen level dependent (BOLD) effect was multifocal, with clusters in lateral and inferior occipital lobe and lateral and anterior temporal lobe. We also performed regional dipole seeding in BOLD clusters to determine their relative contribution to generation of scalp spikes. The integrated model of the neurophysiologic and vascular data strongly suggests that the epileptic activity originates in the lateral occipital area, spreading to the occipital pole and lateral temporal lobe.

  7. Transsynaptic neuronal degeneration of optic nerves associated with bilateral occipital lesions

    Directory of Open Access Journals (Sweden)

    Sachdev Mahipal

    1990-01-01

    Full Text Available A case is reported of a 9-year old male who presented with abnormal behaviour and progressive diminution of vision. Pupils were middilated in both eyes but the pupillary reflexes were preserved. Fundus examination revealed a bilateral optic atrophy and radiological investigations showed a bilateral occipital calcification. We hereby document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions. Transsynapptic neuronal degeneration of optic nerves consequent to occipital lobe lesions is a rare phenomenon. Experimentally occipital lobe ablation in non-human primates has been shown to result in optic atrophy. Herein, we document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions.

  8. The oblique occipital sinus: anatomical study using bone subtraction 3D CT venography.

    Science.gov (United States)

    Shin, Hwa Seon; Choi, Dae Seob; Baek, Hye Jin; Choi, Ho Cheol; Choi, Hye Young; Park, Mi Jung; Kim, Ji Eun; Han, Jeong Yeol; Park, SungEun

    2017-06-01

    An occipital sinus draining into the sigmoid sinus has been termed the oblique occipital sinus (OOS). The frequency, anatomical features, patterns, and relationship with the transverse sinus of the oblique occipital sinus were analyzed in this study. The study included 1805 patients who underwent brain CT angiography during a 3-year period from 2013 to 2015. CT examinations were performed using a 64-slice MDCT system. The OOS was identified in 41 patients (2.3%). There were many anatomical variations in the oblique occipital sinuses. A hypoplastic or aplastic TS was seen in 31 (75.6%) of the 41 patients with OOS. Many anatomical variations in the oblique occipital sinus can be seen on CT venography. Some OOSs function as the main drainage route of the intracranial veins instead of the TS. Thus, careful examination is essential for preoperative evaluation in posterior fossa lesions.

  9. Dissociation of object and spatial visual processing pathways in human extrastriate cortex

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    Haxby, J.V.; Grady, C.L.; Horwitz, B.; Ungerleider, L.G.; Mishkin, M.; Carson, R.E.; Herscovitch, P.; Schapiro, M.B.; Rapoport, S.I. (National Institutes of Health, Bethesda, MD (USA))

    1991-03-01

    The existence and neuroanatomical locations of separate extrastriate visual pathways for object recognition and spatial localization were investigated in healthy young men. Regional cerebral blood flow was measured by positron emission tomography and bolus injections of H2(15)O, while subjects performed face matching, dot-location matching, or sensorimotor control tasks. Both visual matching tasks activated lateral occipital cortex. Face discrimination alone activated a region of occipitotemporal cortex that was anterior and inferior to the occipital area activated by both tasks. The spatial location task alone activated a region of lateral superior parietal cortex. Perisylvian and anterior temporal cortices were not activated by either task. These results demonstrate the existence of three functionally dissociable regions of human visual extrastriate cortex. The ventral and dorsal locations of the regions specialized for object recognition and spatial localization, respectively, suggest some homology between human and nonhuman primate extrastriate cortex, with displacement in human brain, possibly related to the evolution of phylogenetically newer cortical areas.

  10. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    Directory of Open Access Journals (Sweden)

    Akemi Tomoda

    Full Text Available Exposure to interparental violence is associated with negative outcomes, such as depression, post-traumatic stress disorder and reduced cognitive abilities. However, little is known about the potential effects of witnessing domestic violence during childhood on gray matter volume (GMV or cortical thickness. High-resolution 3.0 T volumetric scans (Siemens Trio Scanner were obtained on 52 subjects (18-25 years including 22 (6 males/16 females with a history of visually witnessing episodes of domestic violence, and 30 (8 males/22 females unexposed control subjects, with neither a current nor past DSM-IV Axis I or II disorder. Potential confounding effects of age, gender, level of parental verbal aggression, parental education, financial stress, full scale IQ, and total GMV, or average thickness were modeled using voxel based morphometry and FreeSurfer. Witnessing domestic violence subjects had a 6.1% GMV reduction in the right lingual gyrus (BA18 (P = 0.029, False Discovery Rate corrected peak level. Thickness in this region was also reduced, as was thickness in V2 bilaterally and left occipital pole. Theses regions were maximally sensitive to exposure to witnessing domestic violence between 11-13 years of age. Regional reductions in GMV and thickness were observed in both susceptible and resilient witnessing domestic violence subjects. Results in subjects witnessing domestic violence were similar to previously reported results in subjects with childhood sexual abuse, as the primary region affected was visual cortex. Brain regions that process and convey the adverse sensory input of the abuse may be specifically modified by this experience, particularly in subjects exposed to a single type of maltreatment. Exposure to multiple types of maltreatment is more commonly associated with morphological alterations in corticolimbic regions. These findings fit with preclinical studies showing that visual cortex is a highly plastic structure.

  11. Evaluation of Cerebral Cortex Function in Clients with Bipolar Mood Disorder I (BMD I Compared With BMD II Using QEEG Analysis

    Directory of Open Access Journals (Sweden)

    Ali Khaleghi

    2015-10-01

    Full Text Available Objective: Early diagnosis of type I and type II bipolar mood disorder is very challenging particularly in adolescence. Hence, we aimed to investigate the cerebral cortex function in these patients, using quantitative electroencephalography analysis to obtain significant differences between them.Methods: Thirty- eight adolescents (18 patients with bipolar disorder I and 20 with BMD II participated in this study. We recorded the electroencephalogram signals based on 10-20 international system by 21 electrodes in eyes open and eyes closed condition resting conditions. Forty seconds segments were selected from each recorded signals with minimal noise and artifacts. Periodogram Welch was used to estimate power spectrum density from each segment. Analysis was performed in five frequency bands (delta, theta, alpha, beta and gamma, and we assessed power, mean, entropy, variance and skewness of the spectrums, as well as mean of the thresholded spectrum and thresholded spectrogram. We only used focal montage for comparison. Eventually, data were analyzed by independent Mann-Whitney test and independent t test.Results: We observed significant differences in some brain regions and in all frequency bands. There were significant differences in prefrontal lobe, central lobe, left parietal lobe, occipital lobe and temporal lobe between BMD I and BMD II (P < 0.05. In patients with BMD I, spectral entropy was compared to patients with BMD II. The most significant difference was observed in the gamma frequency band. Also, the power and entropy of delta frequency band was larger in the left parietal lobe in the BMD I patients compared to BMD II patients (P < 0.05. In the temporal lobe, significant differences were observed in the spectrum distribution of beta and gamma frequency bands (P < 0.05.Conclusion: The QEEG and entropy measure are simple and available tools to help detect cerebral cortex deficits and distinguish BMD I from BMD II.

  12. The Occipital Face Area Is Causally Involved in Facial Viewpoint Perception.

    Science.gov (United States)

    Kietzmann, Tim C; Poltoratski, Sonia; König, Peter; Blake, Randolph; Tong, Frank; Ling, Sam

    2015-12-16

    Humans reliably recognize faces across a range of viewpoints, but the neural substrates supporting this ability remain unclear. Recent work suggests that neural selectivity to mirror-symmetric viewpoints of faces, found across a large network of visual areas, may constitute a key computational step in achieving full viewpoint invariance. In this study, we used repetitive transcranial magnetic stimulation (rTMS) to test the hypothesis that the occipital face area (OFA), putatively a key node in the face network, plays a causal role in face viewpoint symmetry perception. Each participant underwent both offline rTMS to the right OFA and sham stimulation, preceding blocks of behavioral trials. After each stimulation period, the participant performed one of two behavioral tasks involving presentation of faces in the peripheral visual field: (1) judging the viewpoint symmetry; or (2) judging the angular rotation. rTMS applied to the right OFA significantly impaired performance in both tasks when stimuli were presented in the contralateral, left visual field. Interestingly, however, rTMS had a differential effect on the two tasks performed ipsilaterally. Although viewpoint symmetry judgments were significantly disrupted, we observed no effect on the angle judgment task. This interaction, caused by ipsilateral rTMS, provides support for models emphasizing the role of interhemispheric crosstalk in the formation of viewpoint-invariant face perception. Faces are among the most salient objects we encounter during our everyday activities. Moreover, we are remarkably adept at identifying people at a glance, despite the diversity of viewpoints during our social encounters. Here, we investigate the cortical mechanisms underlying this ability by focusing on effects of viewpoint symmetry, i.e., the invariance of neural responses to mirror-symmetric facial viewpoints. We did this by temporarily disrupting neural processing in the occipital face area (OFA) using transcranial magnetic

  13. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu [Hiroshima Univ. (Japan). School of Medicine

    1994-09-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6[+-]18.5 to examine the appearance of T2 low signal intensity areas (T[sub 2]-CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T[sub 2]-CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T[sub 2]-CLIA increased with age. Over 70 years of age T[sub 2]-CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T[sub 2]-CLIA was not observed in other cortices. The incidence of T[sub 2]-CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T[sub 2]-CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T[sub 2]-CLIA correlated with white matter lesions. These results suggest that T[sub 2]-CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author).

  14. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

    International Nuclear Information System (INIS)

    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu

    1994-01-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6±18.5 to examine the appearance of T2 low signal intensity areas (T 2 -CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T 2 -CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T 2 -CLIA increased with age. Over 70 years of age T 2 -CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T 2 -CLIA was not observed in other cortices. The incidence of T 2 -CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T 2 -CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T 2 -CLIA correlated with white matter lesions. These results suggest that T 2 -CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author)

  15. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

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    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu (Hiroshima Univ. (Japan). School of Medicine)

    1994-09-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6[+-]18.5 to examine the appearance of T2 low signal intensity areas (T[sub 2]-CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T[sub 2]-CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T[sub 2]-CLIA increased with age. Over 70 years of age T[sub 2]-CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T[sub 2]-CLIA was not observed in other cortices. The incidence of T[sub 2]-CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T[sub 2]-CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T[sub 2]-CLIA correlated with white matter lesions. These results suggest that T[sub 2]-CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author).

  16. The lateralization of motor cortex activation to action words

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    Olaf eHauk

    2011-11-01

    Full Text Available What determines the laterality of activation in motor cortex for words whose meaning is related to bodily actions? It has been suggested that the neuronal representation of the meaning of action-words is shaped by individual experience. However, core language functions are left-lateralized in the majority of both right- and left-handers. It is still an open question to what degree connections between left-hemispheric core language areas and right-hemispheric motor areas can play a role in semantics. We investigated laterality of brain activation using fMRI in right- and left-handed participants in response to visually presented hand-related action-words, namely uni- and bi-manual actions (such as "throw" and "clap". These stimulus groups were matched with respect to general (hand-action-relatedness, but differed with respect to whether they are usually performed with the dominant hand or both hands. We may expect generally more left-hemispheric motor-cortex activation for hand-related words in both handedness groups, with possibly more bilateral activation for bimanual words as well as left-handers. In our study, both participant groups activated motor cortex bilaterally for bi-manual words. Interestingly, both groups also showed a left-lateralized activation pattern to uni-manual words. We argue that this reflects the effect of left-hemispheric language dominance on the formation of semantic brain circuits on the basis of Hebbian correlation learning.

  17. The transperiosteal "inside-out" occipital artery harvesting technique.

    Science.gov (United States)

    Benet, Arnau; Tabani, Halima; Ding, Xinmin; Burkhardt, Jan-Karl; Rodriguez Rubio, Roberto; Tayebi Meybodi, Ali; Nisson, Peyton; Kola, Olivia; Gandhi, Sirin; Yousef, Sonia; Lawton, Michael T

    2018-01-26

    OBJECTIVE The occipital artery (OA) is a frequently used donor vessel for posterior circulation bypass procedures due to its proximity to the recipient vessels and its optimal caliber, length, and flow rate. However, its tortuous course through multiple layers of suboccipital muscles necessitates layer-by-layer dissection. The authors of this cadaveric study aimed to describe a landmark-based novel anterograde approach to harvest OA in a proximal-to-distal "inside-out" fashion, which avoids multilayer dissection. METHODS Sixteen cadaveric specimens were prepared for surgical simulation, and the OA was harvested using the classic (n = 2) and novel (n = 14) techniques. The specimens were positioned three-quarters prone, with 45° contralateral head rotation. An inverted hockey-stick incision was made from the spinous process of C-2 to the mastoid tip, and the distal part of the OA was divided to lift up a myocutaneous flap, including the nuchal muscles. The OA was identified using the occipital groove (OG), the digastric muscle (DM) and its groove (DG), and the superior oblique muscle (SOM) as key landmarks. The OA was harvested anterogradely from the OG and within the flap until the skin incision was reached (proximal-to-distal technique). In addition, 35 dry skulls were assessed bilaterally (n = 70) to study additional craniometric landmarks to infer the course of the OA in the OG. RESULTS The OA was consistently found running in the OG, which was found between the posterior belly of the DM and the SOM. The mean total length of the mobilized OA was 12.8 ± 1.2 cm, with a diameter of 1.3 ± 0.1 mm at the suboccipital segment and 1.1 ± 0.1 mm at the skin incision. On dry skulls, the occipitomastoid suture (OMS) was found to be medial to the OG in the majority of the cases (68.6%), making it a useful landmark to locate the OG and thus the proximal OA. CONCLUSIONS The anterograde transperiosteal inside-out approach for harvesting the OA is a fast and easy technique

  18. Long-term effects of serial anodal tDCS on motion perception in subjects with occipital stroke measured in the unaffected visual hemifield

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    Manuel C Olma

    2013-06-01

    Full Text Available Transcranial direct current stimulation (tDCS is a novel neuromodulatory tool that has seen early transition to clinical trials, although the high variability of these findings necessitates further studies in clincally-relevant populations. The majority of evidence into effects of repeated tDCS is based on research in the human motor system, but it is unclear whether the long-term effects of serial tDCS are motor-specific or transferable to other brain areas. This study aimed to examine whether serial anodal tDCS over the visual cortex can exogenously induce long-term neuroplastic changes in the visual cortex. However, when the visual cortex is affected by a cortical lesion, up-regulated endogenous neuroplastic adaptation processes may alter the susceptibility to tDCS. To this end, motion perception was investigated in the unaffected hemifield of subjects with unilateral visual cortex lesions. Twelve subjects with occipital ischaemic lesions participated in a within-subject, sham-controlled, double-blind study. MRI-registered sham or anodal tDCS (1.5 mA, 20 minutes was applied on five consecutive days over the visual cortex. Motion perception was tested before and after stimulation sessions and at 14- and 28-day follow-up. After a 16-day interval an identical study block with the other stimulation condition (anodal or sham tDCS followed. Serial anodal tDCS over the visual cortex resulted in an improvement in motion perception, a function attributed to MT/V5. This effect was still measurable at 14- and 28-day follow-up measurements. Thus, this may represent evidence for long-term tDCS-induced plasticity and has implications for the design of studies examining the time course of tDCS effects in both the visual and motor systems.

  19. Understanding the Dorsal and Ventral Systems of the Human Cerebral Cortex: Beyond Dichotomies

    Science.gov (United States)

    Borst, Gregoire; Thompson, William L.; Kosslyn, Stephen M.

    2011-01-01

    Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more…

  20. Activation on occipital lobe in children with abacus mental calculation training: an fMRI study

    International Nuclear Information System (INIS)

    Shen Xiaojun; Long Jinfeng; Zhao Kunyuan; Li Lixin; Sun Jining; Wang Bin

    2011-01-01

    Objective: By exploring the activation on occipital lobe in children with and without abacus mental calculation training when they engaged in different calculation tasks with functional magnetic resonance imaging (fMRI), to identify the possible mechanism of occipital lobe in abacus mental calculation. Methods: fMRI was performed in children trained with and without (sixteen in each group) abacus mental calculation when they engaged in addition, subtraction. multiplication, division, and number-object control judging tasks. The data processing and statistical analysis were performed on SPM 2.0 (statistical parametric mapping 2.0) and the related-brain functional areas were identified. The activation on occipital lobe was observed carefully. The difference in activated areas of occipital lobe was statistically significant between two groups engaged in different tasks of calculations (P<0.01). Result: Bilateral occipital lobe, especially in the cuneus and lingual gyrus, were activated in children trained with abacus mental calculation. The main activated area was lingual gyrus in children without abacus mental calculation. Conclusion: The occipital lobe participates visuospatial processing in the abacus mental calculations. The neuromechanism maybe account for the specific activation in occipital lobe. (authors)

  1. Early seizure propagation from the occipital lobe to medial temporal structures and its surgical implication.

    Science.gov (United States)

    Usui, Naotaka; Mihara, Tadahiro; Baba, Koichi; Matsuda, Kazumi; Tottori, Takayasu; Umeoka, Shuichi; Nakamura, Fumihiro; Terada, Kiyohito; Usui, Keiko; Inoue, Yushi

    2008-12-01

    Intracranial EEG documentation of seizure propagation from the occipital lobe to medial temporal structures is relatively rare. We retrospectively analyzed intracranial EEG recorded with electrodes implanted in the medial temporal lobe in patients who underwent occipital lobe surgery. Four patients with occipital lesions, who underwent intracranial EEG monitoring with intracerebral electrodes implanted in the medial temporal lobe prior to occipital lobe surgery, were studied. Subdural electrodes were placed over the occipital lobe and adjacent areas. Intracerebral electrodes were implanted into bilateral hippocampi and the amygdala in three patients, and in the hippocampus and amygdala ipsilateral to the lesion in one. In light of the intracranial EEG findings, the occipital lobe was resected but the medial temporal lobe was spared in all patients. The follow-up period ranged from six to 16 years, and seizure outcome was Engel Class I in all patients. Sixty six seizures were analyzed. The majority of the seizures originated from the occipital lobe. In complex partial seizures, ictal discharges propagated to the medial temporal lobe. No seizures originating from the temporal lobe were documented. In some seizures, the ictal-onset zone could not be identified. In these seizures, very early propagation to the medial temporal lobe was observed. Interictal spikes were recorded in the medial temporal lobe in all cases. Intracranial EEG revealed very early involvement of the medial temporal lobe in some seizures. Seizure control was achieved without resection of the medial temporal structures.

  2. Prevalence of resistant occipital lobe epilepsy associated with celiac disease in children.

    Science.gov (United States)

    Dai, Alper I; Akcali, Aylin; Varan, Celal; Demiryürek, Abdullah T

    2014-06-01

    Celiac disease (CD) is a chronic, inflammatory autoimmune disorder caused by intolerance to ingested gluten. Increased frequency of CD has been reported in occipital lobe epilepsy. The aim of the present study is to investigate the frequency of CD among children followed up due to epilepsy and diagnosed with epileptic activity in the occipital lobe in at least one electroencephalography (EEG) test. For this research, 90 pediatric epilepsy patients with epileptic activity in the occipital lobe were enrolled in the study group, while the control group comprised of 100 healthy children. In addition to the EEG examination, tissue transglutaminase (tTG) antibody was determined on duodenal biopsy. None of the healthy children in the control group was positive in terms of the tTG antibody test used to scan CD. In the group with epileptic activity in the occipital lobe, two patients out of 90 were tTG antibody positive. The seroprevalence was 1/45 (2.22 %) in this group. These two patients were diagnosed with CD based on the endoscopic duodenal biopsy. In these patients, the seizures were uncontrollable through monotherapy. Our results showed that the prevalence of CD is observed to be higher than the normal population among the patients with occipital lobe epilepsy. This type of seizure disorder seems to be more resistant to monotherapy, compared with other types of occipital epilepsy. Therefore, screening for CD is recommended in children with resistant epileptic activity in the occipital lobe.

  3. Atlanto-Occipital Rotatory Dislocation: A Case Report and Systematic Review.

    Science.gov (United States)

    Robles, Luis A; Mundis, Greg M; Cuevas-Solórzano, Abel

    2018-02-01

    Atlanto-occipital rotatory dislocation (AORD) has rarely been reported in the literature; for this reason, the clinicoradiologic characteristics of this injury are not well described. We describe the case of a 67-year-old man who sustained a cervical spine trauma. He reported only neck pain and was neurologically intact. A computed tomography scan showed a rotatory displacement of the atlanto-occipital joints associated with a widened condylar-C1 interval; in addition, magnetic resonance imaging showed injuries to the stabilizing ligaments of this area. A systematic literature review was also performed to identify previous cases of patients with AORD. The patient was treated with craniocervical fixation from occipital to C1, achieving a good outcome. The literature review yielded 9 cases of patients with AORD. Compared with patients with atlanto-occipital dislocation, patients with rotatory dislocations have a less severe degree of displacement of the atlanto-occipital joints and better clinical outcome. Compared with previously classified atlanto-occipital dislocations, AORD is an independent and unique variation. AORD presents with different biomechanical, clinicoradiologic, and prognostic characteristics and represents an important addition to the spectrum of atlanto-occipital dislocation injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Ultrasonography of occipital arteries to diagnose giant cell arteritis: a case series and literature review.

    Science.gov (United States)

    Pinnell, Jonathan; Tiivas, Carl; Perkins, Phillip; Blake, Tim; Saravana, Shanmugam; Dubey, Shirish

    2018-02-01

    We describe four cases of giant cell arteritis (GCA) that presented with occipital headache in the last 6 months. Typical ultrasound features of GCA were found in the occipital arteries which helped to confirm the diagnosis. One patient had already suffered significant visual loss by the time the diagnosis was made, reflecting the similarity in prognosis to the more typical GCA patients. These cases prompted a review of the literature to evaluate the evidence regarding the use of occipital artery ultrasonography in the investigation of GCA. We searched PubMed, Google Scholar and Web of Science and identified 17 papers but only four of these were relevant studies. The studies available show that typical features of GCA can be detected in the occipital arteries using ultrasonography. They also suggest that ultrasonography can detect changes in the occipital arteries when temporal arteries are not involved. However, occipital artery abnormalities were less common than temporal artery abnormalities in GCA. We advocate maintaining a high index of suspicion for GCA in patients presenting with atypical features, such as occipital headache. Ultrasonography has a vital role to play in the diagnosis of these patients. We recommend priority imaging of the affected area to facilitate prompt and accurate diagnosis of GCA, especially when atypical vessels are involved.

  5. Frontal and occipital perfusion changes in dissociative identity disorder.

    Science.gov (United States)

    Sar, Vedat; Unal, Seher N; Ozturk, Erdinc

    2007-12-15

    The aim of the study was to investigate if there were any characteristics of regional cerebral blood flow (rCBF) in dissociative identity disorder. Twenty-one drug-free patients with dissociative identity disorder and nine healthy volunteers participated in the study. In addition to a clinical evaluation, dissociative psychopathology was assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders, the Dissociative Experiences Scale and the Clinician-Administered Dissociative States Scale. A semi-structured interview for borderline personality disorder, the Hamilton Depression Rating Scale, and the Childhood Trauma Questionnaire were also administered to all patients. Normal controls had to be without a history of childhood trauma and without any depressive or dissociative disorder. Regional cerebral blood flow (rCBF) was studied with single photon emission computed tomography (SPECT) with Tc99m-hexamethylpropylenamine (HMPAO) as a tracer. Compared with findings in the control group, the rCBF ratio was decreased among patients with dissociative identity disorder in the orbitofrontal region bilaterally. It was increased in median and superior frontal regions and occipital regions bilaterally. There was no significant correlation between rCBF ratios of the regions of interest and any of the psychopathology scale scores. An explanation for the neurophysiology of dissociative psychopathology has to invoke a comprehensive model of interaction between anterior and posterior brain regions.

  6. Diagnosis of occipital condyle fractures; Diagnostik von Frakturen der Okzipitalkondylen

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    Hefele-Roedel, B. [Radiologische Klinik Innenstadt, Univ. Muenchen (Germany); Vogl, T.J. [Radiologische Klinik Innenstadt, Univ. Muenchen (Germany); Lochbuehler, H. [Dr. v. Haunersches Kinderspital, Kinderchirurgische Klinik, Univ. Muenchen (Germany); Lissner, J. [Radiologische Klinik Innenstadt, Univ. Muenchen (Germany)

    1995-01-01

    Following the conventional X-ray diagnosis of the skull and upper cervical spine, CT proved to be the primary diagnostic method after a skull and brain injury: For all 4 cases we succeeded in detecting the occipital condyle fracture and in determing its size and location by reconstructions (coronal, sagittal, 3-D). In the case of complex occompanying injuries like soft tissue hematomas (cerebral, in the spinal cord, and the soft tissue of the neck) or for the detection of brain stem contusion, MRT had significant advantages. MRT can offer a higher image quality in soft tissue, especially in the spinal cord and the brain. (orig.) [Deutsch] Im Anschluss an die konventionelle Roentgendiagnostik des Schaedels und der Halswirbelsaeule, erwies sich die Computertomographie als primaer einzusetzendes diagnostisches Verfahren, nach erlittenem Schaedel-Hirn-Trauma. In allen Faellen gelang der exakte Frakturnachweis an den Okzipitalkondylen, die Bestimmung des Frakturausmasses und die genaue Frakturlokalisation in Rekonstruktionen (koronar, sagittal, 3-D). Bei komplexen Begleitverletzungen, wie Blutungen (zerebral, spinal und in den Halsweichteilen) oder zum Nachweis einer Hirnstammkontusion, erwies sich der Einsatz der MRT als vorteilhaft. Mit der MRT laesst sich ein deutlich hoeherer Weichteilkontrast, insbesondere spinal und zerebral, erzielen. (orig.)

  7. MRI diagnosis of suspected atlanto-occipital dissociation in childhood

    International Nuclear Information System (INIS)

    Grabb, B.C.; Frye, T.A.; Hedlund, G.L.; Vaid, Y.N.; Royal, S.A.; Grabb, P.A.

    1999-01-01

    Objective. To demonstrate the utility of magnetic resonance (MR) imaging in the diagnosis of complete and partial ligamentous injuries in patients with suspected atlanto-occipital dissociation (AOD). Materials and methods. Five patients with suspected AOD had MR imaging performed within an average of 4 days after injury. MR scans were reviewed with specific analysis of craniocervical ligamentous structures. Charts were reviewed to obtain clinical information regarding presentation, treatment, hospital course, and outcome. Results. Two patients demonstrated MR evidence of complete AOD. One had disruption of all visualized major ligamentous structures at the craniocervical junction with anterolisthesis and evidence of cord damage. The second had injuries to the tectorial membrane, superior band of the cruciform ligament, apical ligament, and interspinous ligament at C 1-2. The remaining three patients sustained incomplete severance of the ligamentous structures at the craniocervical junction. All patients demonstrated subtle radiographic findings suggestive of AOD, including soft tissue swelling at the craniocervical junction without fracture. The two patients with complete AOD died. The three patients with partial AOD were treated with stabilization. On follow-up, these three children were asymptomatic following their craniocervical injury. Conclusion. MR imaging of acute AOD provides accurate identification of the craniocervical ligaments injured, classification of full versus partial ligamentous disruption, and analysis of accompanying spinal cord injury. This information is important for early appropriate neurosurgical management and preservation of neurologic function in survivors. (orig.)

  8. Parieto-occipital encephalomalacia in children; clinical and electrophysiological features of twenty-seven cases.

    Science.gov (United States)

    Karaoğlu, Pakize; Polat, Ayşe İpek; Yiş, Uluç; Hız, Semra

    2015-01-01

    Brain injuries occurring at a particular time may cause damages in well-defined regions of brain. Perinatal hypoxic ischemic encephalopathy and hypoglycemia are some of the most common types of brain injuries. Neonatal hypoglycemia can cause abnormal myelination in parietal and occipital lobes resulting in parieto-occipital encephalomalacia. There is a small number of studies about clinical and electroencephalographic (EEG) features of children with parieto-occipital encephalomalacia. They might have important neurologic sequelae such as cortical visual loss, seizures, and psychomotor retardation. We aimed to evaluate the causes of parieto-occipital encephalomalacia and evaluate the clinical and electrophysiological features of children with parieto-occipital encephalomalacia. We evaluated clinical features and EEGs of 27 children with parieto-occipital encephalomalacia. Descriptive statistics were used. Hospitalization during the neonatal period was the most common cause (88.9%) of parieto-occipital brain injury. Eleven patients (40.7%) had a history of neonatal hypoglycemia. Twenty-three patients (85.2%) had epilepsy and nine of the epileptic patients (39%) had refractory seizures. Most of the patients had bilateral (50%) epileptic discharges originating from temporal, parietal, and occipital lobes (56.2%). However, some patients had frontal sharp waves and some had continuous spike and wave discharges during sleep. Visual abnormalities were evident in 15 (55.6%) patients. Twenty-two (81.5%) had psychomotor retardation. Fine motor skills, social contact and language development were impaired more than gross motor skills. In our study, most of the patients with parieto-occipital encephalomalacia had an eventful perinatal history. Epilepsy, psychomotor retardation, and visual problems were common neurologic complications.

  9. Occipital neuralgia associates with high cervical spinal cord lesions in idiopathic inflammatory demyelinating disease.

    Science.gov (United States)

    Kissoon, Narayan R; Watson, James C; Boes, Christopher J; Kantarci, Orhun H

    2018-01-01

    Background The association of trigeminal neuralgia with pontine lesions has been well documented in multiple sclerosis, and we tested the hypothesis that occipital neuralgia in multiple sclerosis is associated with high cervical spinal cord lesions. Methods We retrospectively reviewed the records of 29 patients diagnosed with both occipital neuralgia and demyelinating disease by a neurologist from January 2001 to December 2014. We collected data on demographics, clinical findings, presence of C2-3 demyelinating lesions, and treatment responses. Results The patients with both occipital neuralgia and multiple sclerosis were typically female (76%) and had a later onset (age > 40) of occipital neuralgia (72%). Eighteen patients (64%) had the presence of C2-3 lesions and the majority had unilateral symptoms (83%) or episodic pain (78%). All patients with documented sensory loss (3/3) had C2-3 lesions. Most patients with progressive multiple sclerosis (6/8) had C2-3 lesions. Of the eight patients with C2-3 lesions and imaging at onset of occipital neuralgia, five (62.5%) had evidence of active demyelination. None of the patients with progressive multiple sclerosis (3/3) responded to occipital nerve blocks or high dose intravenous steroids, whereas all of the other phenotypes with long term follow-up (eight patients) had good responses. Conclusions A cervical spine MRI should be considered in all patients presenting with occipital neuralgia. In patients with multiple sclerosis, clinical features in occipital neuralgia that were predictive of the presence of a C2-3 lesion were unilateral episodic symptoms, sensory loss, later onset of occipital neuralgia, and progressive multiple sclerosis phenotype. Clinical phenotype predicted response to treatment.

  10. A non-invasive, quantitative study of broadband spectral responses in human visual cortex.

    Directory of Open Access Journals (Sweden)

    Eline R Kupers

    Full Text Available Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI and subthreshold neuronal synchrony (oscillations and event-related potentials. In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG-have recently measured broadband power elevation in field potentials (~50-200 Hz as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG. Extracranial measurements like MEG and EEG have multiple global noise sources and relatively low signal-to-noise ratios; moreover high frequency artifacts from eye movements can be confounded with stimulus design and mistaken for signals originating from brain activity. For these reasons, we developed an automated denoising technique that helps reveal the broadband signal of interest. Subjects viewed 12-Hz contrast-reversing patterns in the left, right, or bilateral visual field. Sensor time series were separated into evoked (12-Hz amplitude and broadband components (60-150 Hz. In all subjects, denoised broadband responses were reliably measured in sensors over occipital cortex, even in trials without microsaccades. The broadband pattern was stimulus-dependent, with greater power contralateral to the stimulus. Because we obtain reliable broadband estimates with short experiments (~20 minutes, and with sufficient signal-to-noise to distinguish responses to different stimuli, we conclude that MEG broadband signals, denoised with our method, offer a practical, non-invasive means for characterizing spike-rate-dependent neural activity for addressing scientific questions about human brain function.

  11. Balint′s Syndrome As a Manifestation of Solitary Right Occipital Lobe Metastasis

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    Sarat Chandra P

    1998-01-01

    Full Text Available Balint′s syndrome is a rare clinical condition characterized by a triad of occulomotor apraxia (psychic paralysis of gaze, optic ataxia and visual inattention and usually follows bilateral parieto-occipital lesions. We report this syndrome occurring in a patient with a solitary metastasis in right occipital lobe. To the best of our knowledge it has not been previously described in English literature. Pressure over the opposite occipital lobe due to mass effect, diaschisis and extension of edema along the corpus callosum involvement may contribute to this exceptional phenomenon.

  12. A Giant Occipital Encephalocele in Neonate with Spontaneous Hemorrhage into the Encephalocele Sac: Surgical Management

    Science.gov (United States)

    Satyarthee, Guru Dutta; Moscote-Salazar, Luis Rafael; Escobar-Hernandez, Nidia; Aquino-Matus, Jose; Puac-Polanco, Paulo Cesar; Hoz, Samer S; Calderon-Miranda, Willem Guillermo

    2017-01-01

    The presence of giant occipital encephalocele represents a surgical challenge. However, preoperative magnetic resonance imaging with venography can help in delineating relation of venous sinus, content of the sac and help classify occipital encephalocele into infra-torcular and torcular depending on the relation with position of torcula. However, the presence of old hemorrhage into encephalocele sac is extremely rare and in the detailed PubMed search, the authors could find one such case, reported by Nath et al. The author reports a case of giant occipital encephalocele; during surgery, evidence of old bleed was noted. Pertinent literature and management are reviewed briefly. PMID:29204205

  13. Occipital condyle metastasis: an unusual clinical presentation in carcinoma of the lung

    International Nuclear Information System (INIS)

    Pasricha, R.; Mohanty, P.P.; Madan, R.C.; Datta, N.R.

    2005-01-01

    Metastases to the base of the skull and occipital condyle metastases are uncommon as a presenting feature of malignancy. Lung cancers are known for their metastatic potential to various sites, some of which could be the only presenting feature of the underlying malignancy. However, occipital condyle metastases are very rare and to the best of our knowledge, metastases to this site from carcinoma of the lung, as a presenting feature, have never been reported in the literature. The present case report describes the clinical, radiological and the therapeutic interventions that were undertaken in a patient presenting with lung cancer who had solely the features of occipital condyle metastasis

  14. Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS.

    Science.gov (United States)

    Chen, Ling-Chia; Sandmann, Pascale; Thorne, Jeremy D; Bleichner, Martin G; Debener, Stefan

    2016-01-01

    Cochlear implant (CI) users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH) controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users' speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS). Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation.

  15. Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS

    Directory of Open Access Journals (Sweden)

    Ling-Chia Chen

    2016-01-01

    Full Text Available Cochlear implant (CI users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users’ speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS. Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation.

  16. Left cytoarchitectonic BA 44 processes syntactic gender violations in determiner phrases.

    Science.gov (United States)

    Heim, Stefan; van Ermingen, Muna; Huber, Walter; Amunts, Katrin

    2010-10-01

    Recent neuroimaging studies make contradictory predictions about the involvement of left Brodmann's area (BA) 44 in processing local syntactic violations in determiner phrases (DPs). Some studies suggest a role for BA 44 in detecting local syntactic violations, whereas others attribute this function to the left premotor cortex. Therefore, the present event-related functional magnetic resonance imaging (fMRI) study investigated whether left-cytoarchitectonic BA 44 was activated when German DPs involving syntactic gender violations were compared with correct DPs (correct: 'der Baum'-the[masculine] tree[masculine]; violated: 'das Baum'--the[neuter] tree[masculine]). Grammaticality judgements were made for both visual and auditory DPs to be able to generalize the results across modalities. Grammaticality judgements involved, among others, left BA 44 and left BA 6 in the premotor cortex for visual and auditory stimuli. Most importantly, activation in left BA 44 was consistently higher for violated than for correct DPs. This finding was behaviourally corroborated by longer reaction times for violated versus correct DPs. Additional brain regions, showing the same effect, included left premotor cortex, supplementary motor area, right middle and superior frontal cortex, and left cerebellum. Based on earlier findings from the literature, the results indicate the involvement of left BA 44 in processing local syntactic violations when these include morphological features, whereas left premotor cortex seems crucial for the detection of local word category violations. © 2010 Wiley-Liss, Inc.

  17. Randomized, double-blind, comparative-effectiveness study comparing pulsed radiofrequency to steroid injections for occipital neuralgia or migraine with occipital nerve tenderness.

    Science.gov (United States)

    Cohen, Steven P; Peterlin, B Lee; Fulton, Larry; Neely, Edward T; Kurihara, Connie; Gupta, Anita; Mali, Jimmy; Fu, Diana C; Jacobs, Michael B; Plunkett, Anthony R; Verdun, Aubrey J; Stojanovic, Milan P; Hanling, Steven; Constantinescu, Octav; White, Ronald L; McLean, Brian C; Pasquina, Paul F; Zhao, Zirong

    2015-12-01

    Occipital neuralgia (ON) is characterized by lancinating pain and tenderness overlying the occipital nerves. Both steroid injections and pulsed radiofrequency (PRF) are used to treat ON, but few clinical trials have evaluated efficacy, and no study has compared treatments. We performed a multicenter, randomized, double-blind, comparative-effectiveness study in 81 participants with ON or migraine with occipital nerve tenderness whose aim was to determine which treatment is superior. Forty-two participants were randomized to receive local anesthetic and saline, and three 120 second cycles of PRF per targeted nerve, and 39 were randomized to receive local anesthetic mixed with deposteroid and 3 rounds of sham PRF. Patients, treating physicians, and evaluators were blinded to interventions. The PRF group experienced a greater reduction in the primary outcome measure, average occipital pain at 6 weeks (mean change from baseline -2.743 ± 2.487 vs -1.377 ± 1.970; P occipital pain through 3 months (mean change from baseline -1.925 ± 3.204 vs -0.541 ± 2.644; P = 0.043), and average overall headache pain through 6 weeks (mean change from baseline -2.738 ± 2.753 vs -1.120 ± 2.1; P = 0.037). Adverse events were similar between groups, and few significant differences were noted for nonpain outcomes. We conclude that although PRF can provide greater pain relief for ON and migraine with occipital nerve tenderness than steroid injections, the superior analgesia may not be accompanied by comparable improvement on other outcome measures.

  18. Hemodynamic Response to Featural Changes in the Occipital and Inferior Temporal Cortex in Infants: A Preliminary Methodological Exploration

    Science.gov (United States)

    Wilcox, Teresa; Bortfeld, Heather; Woods, Rebecca; Wruck, Eric; Boas, David A.

    2008-01-01

    Over the past 30 years researchers have learned a great deal about the development of object processing in infancy. In contrast, little is understood about the neural mechanisms that underlie this capacity, in large part because there are few techniques available to measure brain functioning in human infants. The present research examined the…

  19. Study of transpedicular occipital-cervical fusion (report of 17 cases)

    International Nuclear Information System (INIS)

    Zhang Zhiming; Yang Huilin; Yuan Feng; Tang Tiansi

    2004-01-01

    Objective: To introduce a new method for occipital-cervical fusion. Method: Seventeen patients, among them C1, C2 tumor patient 16, all were fixed by transpedicular occipital-cervical fusion before cutting off tumor. Another case was odontoid process fracture. Results: Seventeen patients were visited for 2 years and 3 months on average, and all were fixed good. The patient whose tumor was transferred from the cancer of breast died after half a year for the cancer was extensively transferred, not caused by the surgical operation method. Conclusion: Stability of unstable patients or patients with tumor at occipital-cervical area can be re-constructed by transpedicular occipital-cervical fusion. Before and during operation the precise position must be decided and operation should be carried out carefully. Then good clinical treatment results can be obtained

  20. Posterior atlanto-occipital and atlanto-axial area and its surgical interest

    Directory of Open Access Journals (Sweden)

    Newton José Godoy Pimenta

    2014-10-01

    Full Text Available Classic anatomical studies describe two membranes – atlanto-occipital and atlanto-axial in the posterior aspect of the craniocervical region. During many surgical procedures in this area, however, we have not found such membranes. Objective To clarify the anatomical aspects and structures taking part of the posterior atlanto-occipital and atlanto-axial area. Method Analysis of histological cuts of three human fetuses and anatomical studies of 8 adult human cadavers. Results In both atlanto-occipital and atlanto-axial areas, we have observed attachment between suboccipital deep muscles and the spinal cervical dura. However, anatomical description of such attachments could not be found in textbooks of anatomy. Conclusion Our study shows the absence of the classical atlanto-occipital and atlanto-axial membranes; the occipito-C1 and C1-C2 posterior intervals are an open area, allowing aponeurotic attachment among cervical dura mater and posterior cervical muscles.

  1. Occipital dysplasia and associated cranial spinal cord abnormalities in two dogs

    International Nuclear Information System (INIS)

    Bagley, R.S.; Harrington, M.L.; Tucker, R.L.; Sande, R.D.; Root, C.R.; Kramer, R.W.

    1996-01-01

    Occipital dysplasia was found in association with cervical spinal cord abnormalities in two dogs. One dog presented for tetraparesis and cervical hyperesthesia, the other for historical cervical hyperesthesia and mild paraparesis. In dog 1, a midline cervical spinal cord defect consistent with a communicating syrinx was found. In the other dog, a presumptive syringo/hydromyelia of the cervical spinal cord was found on magnetic resonance imaging. While occipital dysplasia alone is not thought to cause any clinical abnormalities, the dogs of this report suggest that intramedullary central nervous system abnormalities may be present concurrently with occipital dysplasia and should be considered as a possible cause of the clinical signs. The relationship between occipital dysplasia and syringo/hydromyelia in these dogs remains unclear, however, similar associated abnormalities are occasionally found in humans with Chiari malformation

  2. [Complex visual hallucinations following occipital infarct and perception of optical illusions].

    Science.gov (United States)

    Renou, P; Deltour, S; Samson, Y

    2008-05-01

    The physiopathology of visual hallucinations in the hemianopic field secondary to occipital infarct is uncertain. We report the case of a patient with a history of occipital infarct who presented nonstereotyped complex hallucinations in the quadranopic field resulting from a second controlateral occipital infarct. Based on an experience with motion optical illusions, we suggested that the association of these two occipital lesions, involving the V5 motion area on the one side and the V1 area on the other side, could have produced the complex hallucinations due to a release phenomenon. The patient experienced simultaneously a double visual consciousness, with both hallucinations and real visual perceptions. The study of perceptual illusions in patients with visual hallucinations could illustrate the innovative theory of visual consciousness as being not unified but constituted of multiple microconsciousnesses.

  3. Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships in Healthy Humans

    Directory of Open Access Journals (Sweden)

    Nathaniel R. Bridges

    2018-03-01

    Full Text Available Background: Dorsolateral prefrontal cortex (DLPFC low frequency repetitive transcranial magnetic stimulation (LF-rTMS has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed.Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants.Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a 7-letter Sternberg working memory task (SWMT within the left DLPFC. We quantified SWMT performance, functional magnetic resonance activation and proton Magnetic resonance spectroscopy (MRS neurometabolite measure changes before and after stimulation.Results: A single LF-rTMS session was not sufficient to change DLPFC neurometabolite levels and these changes did not correlate with DLPFC activation changes. Real rTMS, however, significantly altered neurometabolite correlations (compared to sham rTMS, both with baseline levels and between the metabolites themselves. Additionally, real rTMS was associated with diminished reaction time (RT performance improvements and increased activation within the motor, somatosensory and lateral occipital cortices.Conclusion: These results show that a single session of LF-rTMS is sufficient to influence metabolite relationships and causes widespread activation in healthy humans. Investigating correlational relationships may provide insight into mechanisms underlying LF-rTMS.

  4. Three Cases with Visual Hallucinations following Combined Ocular and Occipital Damage

    Directory of Open Access Journals (Sweden)

    Bogusław Paradowski

    2013-01-01

    Full Text Available Charles Bonnet syndrome is an underrecognized disease that involves visual hallucinations in visually impaired patients. We present the cases of three patients who experienced complex visual hallucinations following various pathomechanisms. In two cases, diagnosis showed coexistence of occipital lobe damage with ocular damage, while in the third case it showed occipital lobe damage with retrobulbar optic neuritis. Theories of pathogenesis and the neuroanatomical basis of complex visual hallucinations are discussed and supported by literature review.

  5. Perimetric demonstration of spontaneous visual field recovery following occipital lobe haemorrhage.

    Science.gov (United States)

    Lin, Siying; George, Badie Z; Wilson-Holt, Nicholas J

    2013-08-29

    A 45-year-old patient on lifelong warfarin therapy after a metal aortic valve replacement developed a homonymous visual field defect following an occipital lobe haemorrhage. The patient received only conservative management and yet described continued improvement in her visual field defect for up to 20 months following the initial cerebral insult. We present the first conclusive illustrative documentation of visual recovery in a patient with an occipital lobe haemorrhage with sequential automated perimetric assessments over an extended period of time.

  6. Elevated occipital β-amyloid deposition is associated with widespread cognitive impairment in logopenic progressive aphasia.

    Science.gov (United States)

    Whitwell, Jennifer L; Lowe, Val J; Duffy, Joseph R; Strand, Edythe A; Machulda, Mary M; Kantarci, Kejal; Wille, Samantha M; Senjem, Matthew L; Murphy, Matthew C; Gunter, Jeffrey L; Jack, Clifford R; Josephs, Keith A

    2013-12-01

    Most subjects with logopenic variant of primary progressive aphasia (lvPPA) have β-amyloid (Aβ) deposition on Pittsburgh Compound B positron emission tomography (PiB-PET), usually affecting prefrontal and temporoparietal cortices, with less occipital involvement. To assess clinical and imaging features in lvPPA subjects with unusual topographic patterns of Aβ deposition with highest uptake in occipital lobe. Thirty-three lvPPA subjects with Aβ deposition on PiB-PET were included in this case-control study. Line plots of regional PiB uptake were created, including frontal, temporal, parietal and occipital regions, for each subject. Subjects in which the line sloped downwards in occipital lobe (lvPPA-low), representing low uptake, were separated from those where the line sloped upwards in occipital lobe (lvPPA-high), representing unusually high occipital uptake compared to other regions. Clinical variables, atrophy on MRI, hypometabolism on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and presence and distribution of microbleeds and white matter hyperintensities (WMHs) were assessed. Seventeen subjects (52%) were classified as lvPPA-high. Mean occipital PiB uptake in lvPPA-high was higher than all other regions and higher than all regions in lvPPA-low. The lvPPA-high subjects performed more poorly on cognitive testing, including executive and visuospatial testing, but the two groups did not differ in aphasia severity. Proportion of microbleeds and WMH was higher in lvPPA-high than lvPPA-low. Parietal hypometabolism was greater in lvPPA-high than lvPPA-low. Unusually high occipital Aβ deposition is associated with widespread cognitive impairment and different imaging findings in lvPPA. These findings help explain clinical heterogeneity in lvPPA and suggest that Aβ influences severity of overall cognitive impairment but not aphasia.

  7. A Giant Occipital Encephalocele in Neonate with Spontaneous Hemorrhage into the Encephalocele Sac: Surgical Management

    OpenAIRE

    Satyarthee, Guru Dutta; Moscote-Salazar, Luis Rafael; Escobar-Hernandez, Nidia; Aquino-Matus, Jose; Puac-Polanco, Paulo Cesar; Hoz, Samer S; Calderon-Miranda, Willem Guillermo

    2017-01-01

    The presence of giant occipital encephalocele represents a surgical challenge. However, preoperative magnetic resonance imaging with venography can help in delineating relation of venous sinus, content of the sac and help classify occipital encephalocele into infra-torcular and torcular depending on the relation with position of torcula. However, the presence of old hemorrhage into encephalocele sac is extremely rare and in the detailed PubMed search, the authors could find one such case, rep...

  8. A novel technique in airway management of neonates with occipital encephalocele.

    Science.gov (United States)

    Rangaswamy, N; Pramanik, A K

    2014-11-01

    Airway stabilization in neonates with occipital encephalocele (OE) is critical during surgery or if they develop hypoxic-respiratory failure. Endotracheal intubation can be challenging due to difficulty in positioning the head in a patient with large occipital mass. We describe a novel technique for positioning neonates with large OE using a commonly used hospital apparatus which facilitated appropriate positioning of the baby and successful endotracheal intubation with ease and no additional staff.

  9. Missed Total Occlusion Due to the Occipital Artery Arising from the Internal Carotid Artery

    International Nuclear Information System (INIS)

    Ustunsoz, Bahri; Gumus, Burcak; Koksal, Ali; Koroglu, Mert; Akhan, Okan

    2007-01-01

    A 56-year-old man was referred for digital subtraction angiography (DSA) with an ultrasound diagnosis of right proximal internal carotid artery (ICA) stenosis for possible carotid artery stenting. DSA revealed total occlusion of the ICA and an occipital artery arising from the stump and simulating continuation of the ICA. An ascending pharyngeal artery also arose from the same occipital artery. This case is of interest because this is a rare variation besides being a cause of misdiagnosis at carotid ultrasound

  10. In-Depth Review of Symptoms, Triggers, and Treatment of Occipital Migraine Headaches (Site IV).

    Science.gov (United States)

    Ascha, Mona; Kurlander, David E; Sattar, Abdus; Gatherwright, James; Guyuron, Bahman

    2017-06-01

    This study reports the surgical technique and efficacy of deactivation of occipital-triggered migraine headaches. In addition, it reports the effect of surgical deactivation of occipital-triggered migraine headaches on migraine triggers and associated symptoms other than pain. One hundred ninety-five patients undergoing surgery for occipital-triggered migraine headaches performed by a single surgeon, and followed for at least 1 year, were analyzed. Median regression adjusted for age, sex, and follow-up time was used to determine postoperative reduction in occipital-specific Migraine Headache Index, which is the product of migraine duration, frequency, and severity. Reduction in migraine-days was also measured. The association between symptom or trigger resolution and occipital-specific Migraine Headache Index reduction was studied by logistic regression. Details of surgical treatment are discussed and complication rates reported. Eighty-two percent of patients (n = 160) reported successful surgery at least 12 months postoperatively (mean follow-up, 3.67 years). Eighty-six percent (n = 168) had successful surgery as measured by migraine-days. Fifty-two percent reported complete occipital-triggered migraine headaches elimination. Symptoms resolving with successful surgery beyond headache include being bothered by light and noise, feeling lightheaded, difficulty concentrating, vomiting, blurred/double vision, diarrhea, visual aura, numbness and tingling, speech difficulty, and limb weakness (p occipital-triggered migraine headaches provides long-lasting migraine relief. Successful site IV surgery is associated with changes in specific symptoms and triggers. This can assist in trigger avoidance and aid occipital-triggered migraine headache trigger-site identification. Therapeutic, IV.

  11. Decreased occipital lobe metabolism by FDG-PET/CT: An anti-NMDA receptor encephalitis biomarker.

    Science.gov (United States)

    Probasco, John C; Solnes, Lilja; Nalluri, Abhinav; Cohen, Jesse; Jones, Krystyna M; Zan, Elcin; Javadi, Mehrbod S; Venkatesan, Arun

    2018-01-01

    To compare brain metabolism patterns on fluorodeoxyglucose (FDG)-PET/CT in anti-NMDA receptor and other definite autoimmune encephalitis (AE) and to assess how these patterns differ between anti-NMDA receptor neurologic disability groups. Retrospective review of clinical data and initial dedicated brain FDG-PET/CT studies for neurology inpatients with definite AE, per published consensus criteria, treated at a single academic medical center over a 10-year period. Z-score maps of FDG-PET/CT were made using 3-dimensional stereotactic surface projections in comparison to age group-matched controls. Brain region mean Z scores with magnitudes ≥2.00 were interpreted as significant. Comparisons were made between anti-NMDA receptor and other definite AE patients as well as among patients with anti-NMDA receptor based on modified Rankin Scale (mRS) scores at the time of FDG-PET/CT. The medial occipital lobes were markedly hypometabolic in 6 of 8 patients with anti-NMDA receptor encephalitis and as a group (Z = -4.02, interquartile range [IQR] 2.14) relative to those with definite AE (Z = -2.32, 1.46; p = 0.004). Among patients with anti-NMDA receptor encephalitis, the lateral and medial occipital lobes were markedly hypometabolic for patients with mRS 4-5 (lateral occipital lobe Z = -3.69, IQR 1; medial occipital lobe Z = -4.08, 1) compared with those with mRS 0-3 (lateral occipital lobe Z = -0.83, 2; p occipital lobe Z = -1.07, 2; p = 0.001). Marked medial occipital lobe hypometabolism by dedicated brain FDG-PET/CT may serve as an early biomarker for discriminating anti-NMDA receptor encephalitis from other AE. Resolution of lateral and medial occipital hypometabolism may correlate with improved neurologic status in anti-NMDA receptor encephalitis.

  12. Predictors of response to occipital nerve stimulation in refractory chronic headache.

    Science.gov (United States)

    Miller, Sarah; Watkins, Laurence; Matharu, Manjit

    2017-01-01

    Background Occipital nerve stimulation is a promising treatment for refractory chronic headache disorders, but is invasive and costly. Identifying predictors of response would be useful in selecting patients. We present the results of an open-label prospective cohort study of 100 patients (35 chronic migraine, 33 chronic cluster headache, 20 short-lasting unilateral neuralgiform headache attacks and 12 hemicrania continua) undergoing occipital nerve stimulation, using a multivariate binary regression analysis to identify predictors of response. Results Response rate of the cohort was 48%. Multivariate analysis showed short lasting unilateral neuralgiform headache attacks (OR 6.71; 95% CI 1.49-30.05; p = 0.013) and prior response to greater occipital nerve block (OR 4.22; 95% CI 1.35-13.21; p = 0.013) were associated with increased likelihood of response. Presence of occipital pain (OR 0.27; 95% CI 0.09-0.76; p = 0.014) and the presence of severe anxiety and/or depression (as measured on hospital anxiety and depression score) at time of implantation (OR 0.32; 95% CI 0.11-0.91; p = 0.032) were associated with reduced likelihood of response. Conclusion Possible clinical predictors of response to occipital nerve stimulation for refractory chronic headaches have been identified. Our data shows that those with short-lasting unilateral neuralgiform headache attacks respond better than those with chronic migraine, and that a prior response to greater occipital nerve block is associated with positive outcomes. This study suggests that the presence of occipital pain and severe mood disorder at time of implant are both associated with poor outcomes to occipital nerve stimulation.

  13. Origin of frontal lobe spikes in the early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome).

    Science.gov (United States)

    Leal, Alberto J R; Ferreira, José C; Dias, Ana I; Calado, Eulália

    2008-09-01

    Early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome [PS]) is a common and easily recognizable epilepsy. Interictal EEG spike activity is often multifocal but most frequently localized in the occipital lobes. The origin and clinical significance of the extra-occipital spikes remain poorly understood. Three patients with the PS and interictal EEG spikes with frontal lobe topography were studied using high-resolution EEG. Independent component analysis (ICA) was used to decompose the spikes in components with distinct temporal dynamics. The components were mapped in the scalp with a spline-laplacian algorithm. The change in scalp potential topography from spike onset to peak, suggests the contribution of several intracranial generators, with different kinetics of activation and significant overlap. ICA was able to separate the major contributors to frontal spikes and consistently revealed an early activating group of components over the occipital areas in all the patients. The local origin of these early potentials was established by the spline-laplacian montage. Frontal spikes in PS are consistently associated with early and unilateral occipital lobe activation, suggesting a postero-anterior spike propagation. Frontal spikes in the PS represent a secondary activation triggered by occipital interictal discharges and do not represent an independent focus.

  14. Greater Occipital Nerve Treatment in the Management of Spontaneous Intracranial Hypotension Headache: A Case Report.

    Science.gov (United States)

    Niraj, G; Critchley, Peter; Kodivalasa, Mahesh; Dorgham, Mohammed

    2017-06-01

    Clinical presentation of spontaneous intracranial hypotension headache (SIHH) has similarities with postdural puncture headache (PDPH). Recommended treatment for both conditions is an epidural blood patch. Successful outcomes following greater occipital nerve blocks have been reported in the management of PDPH. We present the first report of greater occipital nerve treatment in SIHH. A 40-year-old male presented with a 2-year history of daily postural headaches having a significant impact on quality of life. Magnetic resonance imaging revealed bilateral convexity subdural collections. Post gadolinium scan revealed pachymeningeal enhancement with reduced pontomesencephalic angle below 50 degrees. The patient was offered an epidural blood patch and greater occipital nerve block with corticosteroids. The patient chose occipital nerve block. The patient reported significant short-term benefit lasting 4 months. Thereafter, the patient underwent pulsed radiofrequency treatment to bilateral greater occipital nerves. He reported significant benefit lasting 10 months. Greater occipital nerve treatment may have a role in management of SIHH. © 2017 American Headache Society.

  15. Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

    Directory of Open Access Journals (Sweden)

    Peter J Fried

    Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

  16. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

    Science.gov (United States)

    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  17. Differential effects of bifrontal and occipital nerve stimulation on pain and fatigue using transcranial direct current stimulation in fibromyalgia patients.

    Science.gov (United States)

    To, Wing Ting; James, Evan; Ost, Jan; Hart, John; De Ridder, Dirk; Vanneste, Sven

    2017-07-01

    Fibromyalgia is a disorder characterized by widespread musculoskeletal pain frequently accompanied by other symptoms such as fatigue. Moderate improvement from pharmacological and non-pharmacological treatments have proposed non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) to the occipital nerve (more specifically the C2 area) or to the dorsolateral prefrontal cortex (DLPFC) as potential treatments. We aimed to explore the effectiveness of