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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. 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.

  5. Left occipital craniotomy for resection of falcotentorial meningioma.

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    Couldwell, William T

    2017-10-01

    A 49-year-old man presented with headache and cognitive difficulty. MRI demonstrated a meningioma in the falcotentorial region with compression of the internal cerebral veins, basal veins of Rosenthal, and vein of Galen. It was a removed via a left-sided occipital interhemispheric approach, performed with the patient in the lateral position. After tumor debulking and removal of its attachment to the tentorium and anterior falx, the tumor was resected. All venous structures were preserved. The video demonstrates the technical nuances and strategy for removal of tumors in a region with complicated venous anatomy that must be preserved. The video can be found here: https://youtu.be/wKqAn3dYu4E .

  6. Timing of emotion representation in right and left occipital region: Evidence from combined TMS-EEG.

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    Mattavelli, Giulia; Rosanova, Mario; Casali, Adenauer G; Papagno, Costanza; Romero Lauro, Leonor J

    2016-07-01

    Neuroimaging and electrophysiological studies provide evidence of hemispheric differences in processing faces and, in particular, emotional expressions. However, the timing of emotion representation in the right and left hemisphere is still unclear. Transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) was used to explore cortical responsiveness during behavioural tasks requiring processing of either identity or expression of faces. Single-pulse TMS was delivered 100ms after face onset over the medial prefrontal cortex (mPFC) while continuous EEG was recorded using a 60-channel TMS-compatible amplifier; right premotor cortex (rPMC) was also stimulated as control site. The same face stimuli with neutral, happy and fearful expressions were presented in separate blocks and participants were asked to complete either a facial identity or facial emotion matching task. Analyses performed on posterior face specific EEG components revealed that mPFC-TMS reduced the P1-N1 component. In particular, only when an explicit expression processing was required, mPFC-TMS interacted with emotion type in relation to hemispheric side at different timing; the first P1-N1 component was affected in the right hemisphere whereas the later N1-P2 component was modulated in the left hemisphere. These findings support the hypothesis that the frontal cortex exerts an early influence on the occipital cortex during face processing and suggest a different timing of the right and left hemisphere involvement in emotion discrimination. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 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.

  8. 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.

  9. [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.

  10. 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

  11. 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.

  12. The role of left posterior inferior temporal cortex in spelling.

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    Rapcsak, Steven Z; Beeson, Pélagie M

    2004-06-22

    To determine whether damage to left posterior inferior temporal cortex (PITC) is associated with agraphia and to characterize the nature of the spelling impairment. Left angular gyrus may play a critical role in spelling. However, this traditional view is challenged by reports of agraphia after left temporo-occipital lesions and by functional imaging studies demonstrating activation of left PITC during writing in normal individuals. Patients with focal damage to the left temporo-occipital cortex and normal control subjects were administered a comprehensive spelling battery that included regular words, irregular words, and nonwords as stimuli. Although patients performed worse than control subjects in all experimental conditions, the spelling deficit was particularly severe for irregular words, whereas regular word and nonword spelling were less impaired. Additional analyses indicated that orthographic regularity and word frequency had a much more pronounced effect on spelling accuracy in patients compared with control subjects. Most errors on irregular words were phonologically plausible, consistent with reliance on a sublexical phonologic spelling strategy (i.e., phoneme-grapheme conversion). Overall, the spelling impairment of the patients showed the characteristic profile of lexical agraphia. Lesion analyses indicated that the damage in the majority of patients encompassed an area within the left PITC (BA 37/20) where the authors previously obtained evidence of activation in a functional imaging study of writing in normal participants. The behavioral and neuroanatomic observations in the patients are consistent with functional imaging studies of writing in neurologically intact individuals and provide converging evidence for the role of left PITC in spelling. Together, these findings implicate left PITC as a possible neural substrate of the putative orthographic lexicon that contains stored memory representations for the written forms of familiar words.

  13. Macular pigment carotenoids in the retina and occipital cortex are related in humans.

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    Vishwanathan, Rohini; Schalch, Wolfgang; Johnson, Elizabeth J

    2016-01-01

    Lutein and zeaxanthin are dietary carotenoids that preferentially accumulate in the macular region of the retina. Together with meso-zeaxanthin, a conversion product of lutein in the macula, they form the macular pigment. Lutein is also the predominant carotenoid in human brain tissue and lutein status is associated with cognitive function in adults. The study objective was to evaluate the relationship between retinal and brain lutein and zeaxanthin in humans. Donated brain tissue (occipital cortex and hippocampus) and matched retina were obtained from the National Disease Research Interchange, a national human tissue resource center which adheres to strict consent and confidentiality procedures. Decedents were men and women aged >50 years who either had normal cognitive function or Alzheimer's disease. Tissues were analyzed using standard lipid extractions followed by analysis on reverse-phase high performance liquid chromatography (HPLC) and normal-phase HPLC (for meso-zeaxanthin). Macular pigment carotenoids (lutein, meso-zeaxanthin, and zeaxanthin combined) in the retina were significantly related to the combined concentrations of lutein and zeaxanthin in the occipital cortex. When analyzed separately, only retinal lutein (plus meso-zeaxanthin), not zeaxanthin, was significantly related to lutein in the occipital cortex. No correlations were observed with lutein and zeaxanthin in the hippocampus. Total macular pigment density measured via non-invasive, psychophysical techniques can be used as a biomarker to ascertain brain lutein and zeaxanthin status in clinical studies.

  14. 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

    2008-01-01

    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...

  15. Role of the human retrosplenial cortex/parieto-occipital sulcus in perspective priming.

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    Sulpizio, Valentina; Committeri, Giorgia; Lambrey, Simon; Berthoz, Alain; Galati, Gaspare

    2016-01-15

    The ability to imagine the world from a different viewpoint is a fundamental competence for spatial reorientation and for imagining what another individual sees in the environment. Here, we investigated the neural bases of such an ability using functional magnetic resonance imaging. Healthy participants detected target displacements across consecutive views of a familiar virtual room, either from the perspective of an avatar (primed condition) or in the absence of such a prime (unprimed condition). In the primed condition, the perspective at test always corresponded to the avatar's perspective, while in the unprimed condition it was randomly chosen as 0, 45 or 135deg of viewpoint rotation. We observed a behavioral advantage in performing a perspective transformation during the primed condition as compared to an equivalent amount of unprimed perspective change. Although many cortical regions (dorsal parietal, parieto-temporo-occipital junction, precuneus and retrosplenial cortex/parieto-occipital sulcus or RSC/POS) were involved in encoding and retrieving target location from different perspectives and were modulated by the amount of viewpoint rotation, the RSC/POS was the only area showing decreased activity in the primed as compared to the unprimed condition, suggesting that this region anticipates the upcoming perspective change. The retrosplenial cortex/parieto-occipital sulcus appears to play a special role in the allocentric coding of heading directions. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Temporal Evolution of Target Representation, Movement Direction Planning, and Reach Execution in Occipital-Parietal-Frontal Cortex: An fMRI Study.

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    Cappadocia, David C; Monaco, Simona; Chen, Ying; Blohm, Gunnar; Crawford, J Douglas

    2017-11-01

    The cortical mechanisms for reach have been studied extensively, but directionally selective mechanisms for visuospatial target memory, movement planning, and movement execution have not been clearly differentiated in the human. We used an event-related fMRI design with a visuospatial memory delay, followed by a pro-/anti-reach instruction, a planning delay, and finally a "go" instruction for movement. This sequence yielded temporally separable preparatory responses that expanded from modest parieto-frontal activation for visual target memory to broad occipital-parietal-frontal activation during planning and execution. Using the pro/anti instruction to differentiate visual and motor directional selectivity during planning, we found that one occipital area showed contralateral "visual" selectivity, whereas a broad constellation of left hemisphere occipital, parietal, and frontal areas showed contralateral "movement" selectivity. Temporal analysis of these areas through the entire memory-planning sequence revealed early visual selectivity in most areas, followed by movement selectivity in most areas, with all areas showing a stereotypical visuo-movement transition. Cross-correlation of these spatial parameters through time revealed separate spatiotemporally correlated modules for visual input, motor output, and visuo-movement transformations that spanned occipital, parietal, and frontal cortex. These results demonstrate a highly distributed occipital-parietal-frontal reach network involved in the transformation of retrospective sensory information into prospective movement plans. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

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    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.

  18. Reading without the left ventral occipito-temporal cortex

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    Seghier, Mohamed L.; Neufeld, Nicholas H.; Zeidman, Peter; Leff, Alex P.; Mechelli, Andrea; Nagendran, Arjuna; Riddoch, Jane M.; Humphreys, Glyn W.; Price, Cathy J.

    2012-01-01

    The left ventral occipito-temporal cortex (LvOT) is thought to be essential for the rapid parallel letter processing that is required for skilled reading. Here we investigate whether rapid written word identification in skilled readers can be supported by neural pathways that do not involve LvOT. Hypotheses were derived from a stroke patient who acquired dyslexia following extensive LvOT damage. The patient followed a reading trajectory typical of that associated with pure alexia, re-gaining the ability to read aloud many words with declining performance as the length of words increased. Using functional MRI and dynamic causal modelling (DCM), we found that, when short (three to five letter) familiar words were read successfully, visual inputs to the patient’s occipital cortex were connected to left motor and premotor regions via activity in a central part of the left superior temporal sulcus (STS). The patient analysis therefore implied a left hemisphere “reading-without-LvOT” pathway that involved STS. We then investigated whether the same reading-without-LvOT pathway could be identified in 29 skilled readers and whether there was inter-subject variability in the degree to which skilled reading engaged LvOT. We found that functional connectivity in the reading-without-LvOT pathway was strongest in individuals who had the weakest functional connectivity in the LvOT pathway. This observation validates the findings of our patient’s case study. Our findings highlight the contribution of a left hemisphere reading pathway that is activated during the rapid identification of short familiar written words, particularly when LvOT is not involved. Preservation and use of this pathway may explain how patients are still able to read short words accurately when LvOT has been damaged. PMID:23017598

  19. Oxidative and glicolytic metabolism of the frontal cortex (latero-frontal) and of the posterior cortex (latero-occipital) in relation with the sexual activity of the rat.

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    Menéndez-Patterson, A; Florez-Lozano, J A; Marin, B

    1976-01-01

    The authors of this paper have ascertained the glycolytic metabolism and the oxidative metabolism (intake of QO2), of the frontal and posterior cortex in female rats at different stages of the sexual cycle, as also in ovariectomized animals, by the intake of glucose and the production of lactates. The results indicate a statistically significant increase of the oxidative metabolism of the posterior cortex (latero-occipital) in the estrual and proestrual phases, in comparisons with the diestral phase. The frontal cortex (latero-frontal) did not show any significant difference; moreover, the glycolitic metabolism did not alter in any of the tissues under observation. These findings, seem to suggest possible participation of the posterior cortex (latero-occipital) on the regulation of sexual cycle of the rat. The activation of this cortex occurs through the preponderant imbricantion of the tri-carboxylic acid cycle.

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

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    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.

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

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    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.

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

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    Lieblein-Boff, Jacqueline C; Johnson, Elizabeth J; Kennedy, Adam D; Lai, Chron-Si; Kuchan, Matthew J

    2015-01-01

    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.

  3. 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.

  4. 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.

  5. Neural Responses to Central and Peripheral Objects in the Lateral Occipital Cortex

    Science.gov (United States)

    Wang, Bin; Guo, Jiayue; Yan, Tianyi; Ohno, Seiichiro; Kanazawa, Susumu; Huang, Qiang; Wu, Jinglong

    2016-01-01

    Human object recognition and classification depend on the retinal location where the object is presented and decrease as eccentricity increases. The lateral occipital complex (LOC) is thought to be preferentially involved in the processing of objects, and its neural responses exhibit category biases to objects presented in the central visual field. However, the nature of LOC neural responses to central and peripheral objects remains largely unclear. In the present study, we used functional magnetic resonance imaging (fMRI) and a wide-view presentation system to investigate neural responses to four categories of objects (faces, houses, animals, and cars) in the primary visual cortex (V1) and the lateral visual cortex, including the LOC and the retinotopic areas LO-1 and LO-2. In these regions, the neural responses to objects decreased as the distance between the location of presentation and center fixation increased, which is consistent with the diminished perceptual ability that was found for peripherally presented images. The LOC and LO-2 exhibited significantly positive neural responses to all eccentricities (0–55°), but LO-1 exhibited significantly positive responses only to central eccentricities (0–22°). By measuring the ratio relative to V1 (RRV1), we further demonstrated that eccentricity, category and the interaction between them significantly affected neural processing in these regions. LOC, LO-1, and LO-2 exhibited larger RRV1s when stimuli were presented at an eccentricity of 0° compared to when they were presented at the greater eccentricities. In LOC and LO-2, the RRV1s for images of faces, animals and cars showed an increasing trend when the images were presented at eccentricities of 11 to 33°. However, the RRV1s for houses showed a decreasing trend in LO-1 and no difference in the LOC and LO-2. We hypothesize, that when houses and the images in the other categories were presented in the peripheral visual field, they were processed via

  6. 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

  7. 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

    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...

  8. 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.

  9. Bodies are Represented as Wholes Rather Than Their Sum of Parts in the Occipital-Temporal Cortex.

    Science.gov (United States)

    Brandman, Talia; Yovel, Galit

    2016-02-01

    Behavioral studies suggested that bodies are represented as wholes rather than in a part-based manner. However, neural selectivity for body stimuli is found for both whole bodies and body parts. It is therefore undetermined whether the neural representation of bodies is configural or part-based. We used functional MRI to test the role of first-order configuration on body representation in the human occipital-temporal cortex by comparing the response to a whole body versus the sum of its parts. Results show that body-selective areas, whether defined by selectivity to headless bodies or body parts, preferred whole bodies over their sum of parts and successfully decoded body configuration. This configural representation was specific to body stimuli and not found for faces. In contrast, general object areas showed no preference for wholes over parts and decoded the configuration of both bodies and faces. Finally, whereas effects of inversion on configural face representation were specific to face-selective mechanisms, effects of body inversion were not unique to body-selective mechanisms. We conclude that the neural representation of body parts is strengthened by their arrangement into an intact body, thereby demonstrating a central role of first-order configuration in the neural representation of bodies in their category-selective areas. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

    OpenAIRE

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

    2017-01-01

    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...

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

    OpenAIRE

    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

    Background 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. Methods Surface-based brain morphometry was performed in 35 women and 29 men with ADHD using Free...

  12. Asymmetric oculomotor apraxia, optic ataxia, and simultanagnosia with right hemispatial neglect from a predominantly left-sided lesion of the parieto-occipital area.

    Science.gov (United States)

    Sakurai, Yasuhisa; Fujimoto, Masanori; Hamada, Kensuke; Sugimoto, Izumi

    2018-01-01

    Bálint's syndrome involves bilateral damage to the parieto-occipital area. The extent of the effect of unilateral damage on the Bálint's triad (oculomotor apraxia, optic ataxia, and simultanagnosia) remains unknown. We examined a 63-year-old, right-handed woman who developed right hemianopia, oculomotor apraxia, optic ataxia, simultanagnosia, and hemispatial neglect (HSN) for the right after a cerebral infarction, with detailed neuropsychological tests, magnetic resonance imaging, and single photon emission computed tomography (SPECT). Neuropsychological examination showed that oculomotor apraxia, optic ataxia, and simultanagnosia were more pronounced in the right hemi-space, probably due to the limited eye movement in the right visual field, whereas HSN was restricted to the right hemi-space. Diffusion-weighted MR images revealed hyperintensity in the left parieto-temporo-occipital region, and several spotty areas of the bilateral frontal and parietal subcortical regions. SPECT revealed hypoperfusion in the left parieto-occipital region and frontal operculum and small areas of the right superior parietal lobule. The case suggests that asymmetric (more pronounced in the right hemi-space) oculomotor apraxia, optic ataxia, and simultanagnosia occur in an extensive lesion of the left parieto-occipital cortices. Although HSN is not a prerequisite for simultanagnosia, the coexistence of HSN aggravates simultanagnosia in the hemi-space opposite the lesion.

  13. 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

  14. 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

  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. White matter integrity between left basal ganglia and left prefrontal cortex is compromised in gambling disorder.

    Science.gov (United States)

    van Timmeren, Tim; Jansen, Jochem M; Caan, Matthan W A; Goudriaan, Anna E; van Holst, Ruth J

    2017-11-01

    Pathological gambling (PG) is a behavioral addiction characterized by an inability to stop gambling despite the negative consequences, which may be mediated by cognitive flexibility deficits. Indeed, impaired cognitive flexibility has previously been linked to PG and also to reduced integrity of white matter connections between the basal ganglia and the prefrontal cortex. It remains unclear, however, how white matter integrity problems relate to cognitive inflexibility seen in PG. We used a cognitive switch paradigm during functional magnetic resonance imaging in pathological gamblers (PGs; n = 26) and healthy controls (HCs; n = 26). Cognitive flexibility performance was measured behaviorally by accuracy and reaction time on the switch task, while brain activity was measured in terms of blood oxygen level-dependent responses. We also used diffusion tensor imaging on a subset of data (PGs = 21; HCs = 21) in combination with tract-based spatial statistics and probabilistic fiber tracking to assess white matter integrity between the basal ganglia and the dorsolateral prefrontal cortex. Although there were no significant group differences in either task performance, related neural activity or tract-based spatial statistics, PGs did show decreased white matter integrity between the left basal ganglia and prefrontal cortex. Our results complement and expand similar findings from a previous study in alcohol-dependent patients. Although we found no association between white matter integrity and task performance here, decreased white matter connections may contribute to a diminished ability to recruit prefrontal networks needed for regulating behavior in PG. Hence, our findings could resonate an underlying risk factor for PG, and we speculate that these findings may extend to addiction in general. © 2016 Society for the Study of Addiction.

  17. The role of the lateral occipital cortex in aesthetic appreciation of representational and abstract paintings: a TMS study.

    Science.gov (United States)

    Cattaneo, Zaira; Lega, Carlotta; Ferrari, Chiara; Vecchi, Tomaso; Cela-Conde, Camilo José; Silvanto, Juha; Nadal, Marcos

    2015-04-01

    Neuroimaging studies of aesthetic appreciation have shown that activity in the lateral occipital area (LO)-a key node in the object recognition pathway-is modulated by the extent to which visual artworks are liked or found beautiful. However, the available evidence is only correlational. Here we used transcranial magnetic stimulation (TMS) to investigate the putative causal role of LO in the aesthetic appreciation of paintings. In our first experiment, we found that interfering with LO activity during aesthetic appreciation selectively reduced evaluation of representational paintings, leaving appreciation of abstract paintings unaffected. A second experiment demonstrated that, although the perceived clearness of the images overall positively correlated with liking, the detrimental effect of LO TMS on aesthetic appreciation does not owe to TMS reducing perceived clearness. Taken together, our findings suggest that object-recognition mechanisms mediated by LO play a causal role in aesthetic appreciation of representational art. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Waves of awareness for occipital and parietal phosphenes perception.

    Science.gov (United States)

    Bagattini, Chiara; Mazzi, Chiara; Savazzi, Silvia

    2015-04-01

    Transcranial magnetic stimulation (TMS) of the occipital cortex is known to induce visual sensations, i.e. phosphenes, which appear as flashes of light in the absence of an external stimulus. Recent studies have shown that TMS can produce phosphenes also when the intraparietal sulcus (IPS) is stimulated. The main question addressed in this paper is whether parietal phosphenes are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Electroencephalographic (EEG) signals were recorded while stimulating left occipital or parietal cortices inducing phosphene perception in healthy participants and in a hemianopic patient who suffered from complete destruction of the early visual cortex of the left hemisphere. Results in healthy participants showed that the onset of phosphene perception induced by occipital TMS correlated with differential cortical activity in temporal sites while the onset of phosphene perception induced by parietal TMS correlated with differential cortical activity in the stimulated parietal site. Moreover, IPS-TMS of the lesioned hemisphere of the hemianopic patient with a complete lesion to V1 showed again that the onset of phosphene perception correlated with differential cortical activity in the stimulated parietal site. The present data seem thus to suggest that temporal and parietal cortices can serve as different local early gatekeepers of perceptual awareness and that activity in the occipital cortex, although being relevant for perception in general, is not part of the neural bases of the perceptual awareness of phosphenes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. 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 (pchildren 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.

  20. 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.

  1. 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.

  2. Language and Memory Improvements following tDCS of Left Lateral Prefrontal Cortex.

    Directory of Open Access Journals (Sweden)

    Erika K Hussey

    Full Text Available Recent research demonstrates that performance on executive-control measures can be enhanced through brain stimulation of lateral prefrontal regions. Separate psycholinguistic work emphasizes the importance of left lateral prefrontal cortex executive-control resources during sentence processing, especially when readers must override early, incorrect interpretations when faced with temporary ambiguity. Using transcranial direct current stimulation, we tested whether stimulation of left lateral prefrontal cortex had discriminate effects on language and memory conditions that rely on executive-control (versus cases with minimal executive-control demands, even in the face of task difficulty. Participants were randomly assigned to receive Anodal, Cathodal, or Sham stimulation of left lateral prefrontal cortex while they (1 processed ambiguous and unambiguous sentences in a word-by-word self-paced reading task and (2 performed an n-back memory task that, on some trials, contained interference lure items reputed to require executive-control. Across both tasks, we parametrically manipulated executive-control demands and task difficulty. Our results revealed that the Anodal group outperformed the remaining groups on (1 the sentence processing conditions requiring executive-control, and (2 only the most complex n-back conditions, regardless of executive-control demands. Together, these findings add to the mounting evidence for the selective causal role of left lateral prefrontal cortex for executive-control tasks in the language domain. Moreover, we provide the first evidence suggesting that brain stimulation is a promising method to mitigate processing demands encountered during online sentence processing.

  3. [A clinical study of the number processing system: decimal size effects on reading numbers in patients with left parieto-occipital gliomas].

    Science.gov (United States)

    Gasparini, F M; Cohen, L; Lopes, M; Denvil, D; Capelle, L; Duffau, H; Van Effenterre, R

    2005-04-01

    An increasing number of studies are focusing on the anatomo-functional organisation of number processing and some cognitive models have been recently developed. Nevertheless, relationships between areas implicated in number processing, and language areas and circuits remain unclear. Recently, Dehaene and Cohen, in their "triple-code model of number processing", (Dehaene and Cohen, 1995) distinguished two alternative number representation and processing systems: one depending on verbal processes, the other representing a quantity manipulation. According to this model, the retrieval of "arithmetical facts" (AF), learned by rote at school and memorised in a verbal form (such as the multiplication table or simple addition problems) can be considered as a verbal automatism; conversely, subtraction problems, which require mental manipulation of the quantities, represent an abstract, semantic elaboration: "Actual Calculation" (AC). The anatomical correlate of the retrieval of AF (depending on automatic verbal associations) seems to correspond to the left-hemispheric perisylvian areas, while impairment of the actual calculation (AC) depends on the intraparietal region, particularly in the left dominant hemisphere. The present study describes the neuropsychological assessment of three patients, tested after surgery for left parieto-occipital tumors. Two of them were affected by an anaplasic glioma, the third by a low-grade glioma. The cognitive evaluation included: words of Rey, numeral (directed and reversed) span, reading of "simple" numbers (from 1 to 10) and of "complex" numbers (many decimals), writing (dictation) and reading a standard text, finger denomination and right-left distinction. All patients showed language disturbances, dysgraphia and severe dyslexia. In reading numbers, we identified two types of errors: lexical and syntactic. "Lexical errors" consisted in a wrong choice among words in the number's lexicon. For instance, all patients made errors in reading

  4. Enhanced neural synchrony between left auditory and premotor cortex is associated with successful phonetic categorization.

    Science.gov (United States)

    Alho, Jussi; Lin, Fa-Hsuan; Sato, Marc; Tiitinen, Hannu; Sams, Mikko; Jääskeläinen, Iiro P

    2014-01-01

    The cortical dorsal auditory stream has been proposed to mediate mapping between auditory and articulatory-motor representations in speech processing. Whether this sensorimotor integration contributes to speech perception remains an open question. Here, magnetoencephalography was used to examine connectivity between auditory and motor areas while subjects were performing a sensorimotor task involving speech sound identification and overt repetition. Functional connectivity was estimated with inter-areal phase synchrony of electromagnetic oscillations. Structural equation modeling was applied to determine the direction of information flow. Compared to passive listening, engagement in the sensorimotor task enhanced connectivity within 200 ms after sound onset bilaterally between the temporoparietal junction (TPJ) and ventral premotor cortex (vPMC), with the left-hemisphere connection showing directionality from vPMC to TPJ. Passive listening to noisy speech elicited stronger connectivity than clear speech between left auditory cortex (AC) and vPMC at ~100 ms, and between left TPJ and dorsal premotor cortex (dPMC) at ~200 ms. Information flow was estimated from AC to vPMC and from dPMC to TPJ. Connectivity strength among the left AC, vPMC, and TPJ correlated positively with the identification of speech sounds within 150 ms after sound onset, with information flowing from AC to TPJ, from AC to vPMC, and from vPMC to TPJ. Taken together, these findings suggest that sensorimotor integration mediates the categorization of incoming speech sounds through reciprocal auditory-to-motor and motor-to-auditory projections.

  5. 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.

  6. Are there excitability changes in the hand motor cortex during speech in left-handed subjects?

    Science.gov (United States)

    Tokimura, Hiroshi; Tokimura, Yoshika; Arita, Kazunori

    2012-01-01

    Hemispheric dominance was investigated in left-handed subjects using single transcranial magnetic stimulation to assess the possible effect of forced change in the dominant hand. Single transcranial magnetic stimuli were delivered randomly over the hand area of the left or right motor cortex of 8 Japanese self-declared left-handed adult volunteers. Electromyographic responses were recorded in the relaxed first dorsal interosseous muscle while the subjects read aloud. Laterality quotient calculated by the Edinburgh Inventory ranged from -100 to -5.26 and laterality index calculated from motor evoked potentials ranged from -86.2 to 38.8. There was no significant correlation between laterality quotient and laterality index. Mean data values across all 8 subjects indicated significant increases only in the left hand. Our ratio analysis of facilitation of the hand motor potentials showed that 2 each of the 8 self-declared left-handers were right- and left-hand dominant and the other 4 were bilateral-hand dominant. Speech dominancy was localized primarily in the right cerebral hemisphere in left-handed subjects, but some individuals exhibited bilateral or left dominance, possibly attributable to the forced change of hand preference for writing in childhood. Our findings suggest changes in the connections between the speech and hand motor areas.

  7. 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.

  8. Bilateral bifid occipital condyles presenting with the right accessory ...

    African Journals Online (AJOL)

    Unlike the left occipital condyle the right occipital condyle contained an additional oblique cleft that separated the left caudal occipital segment into the inner main portion and the outer accessory articular surface. The accessory articular surface was concave in shape and covered with the articular cartilage. The exact ...

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

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    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.

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

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    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.

  11. Cathodal tDCS over the left prefrontal cortex diminishes choice-induced preference change.

    Science.gov (United States)

    Mengarelli, Flavia; Spoglianti, Silvia; Avenanti, Alessio; di Pellegrino, Giuseppe

    2015-05-01

    In everyday life, people often find themselves facing difficult decisions between options that are equally attractive. Cognitive dissonance theory states that after making a difficult choice between 2 equally preferred options, individuals no longer find the alternatives similarly desirable. Rather, they often change their existing preferences to align more closely with the choice they have just made. Despite the relevance of cognitive dissonance in modulating behavior, little is known about the brain processes crucially involved in choice-induced preference change. In the present study, we applied cathodal transcranial Direct Current Stimulation (tDCS) with the aim of downregulating the activity of the left or the right dorsolateral prefrontal cortex (DLPFC) during a revised version of Brehm's (in 1956. Post-decision changes in the desirability of alternatives. J Abnorm Soc Psychol. 52:384-389) free-choice paradigm. We found that cathodal tDCS over the left, but not over the right, DLPFC caused a reduction of the typical behavior-induced preference change relative to sham stimulation. Our findings highlight the role of prefrontal cortex in cognitive dissonance and provide evidence that left DLPFC plays a necessary role in the implementation of choice-induced preference change. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Independent representations of verbs and actions in left lateral temporal cortex.

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    Peelen, Marius V; Romagno, Domenica; Caramazza, Alfonso

    2012-10-01

    Verbs and nouns differ not only on formal linguistic grounds but also in what they typically refer to: Verbs typically refer to actions, whereas nouns typically refer to objects. Prior neuroimaging studies have revealed that regions in the left lateral temporal cortex (LTC), including the left posterior middle temporal gyrus (pMTG), respond selectively to action verbs relative to object nouns. Other studies have implicated the left pMTG in action knowledge, raising the possibility that verb selectivity in LTC may primarily reflect action-specific semantic features. Here, using functional neuroimaging, we test this hypothesis. Participants performed a simple memory task on visually presented verbs and nouns that described either events (e.g., "he eats" and "the conversation") or states (e.g., "he exists" and "the value"). Verb-selective regions in the left pMTG and the left STS were defined in individual participants by an independent localizer contrast between action verbs and object nouns. Both regions showed equally strong selectivity for event and state verbs relative to semantically matched nouns. The left STS responded more to states than events, whereas there was no difference between states and events in the left pMTG. Finally, whole-brain group analysis revealed that action verbs, relative to state verbs, activated a cluster in pMTG that was located posterior to the verb-selective pMTG clusters. Together, these results indicate that verb selectivity in LTC is independent of action representations. We consider other differences between verbs and nouns that may underlie verb selectivity in LTC, including the verb property of predication.

  13. 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.

  14. Classic identity negative priming involves accessing semantic representations in the left anterior temporal cortex.

    Science.gov (United States)

    de Zubicaray, Greig; McMahon, Katie; Eastburn, Mathew; Pringle, Alan; Lorenz, Lina

    2006-10-15

    Classic identity negative priming (NP) refers to the finding that when an object is ignored, subsequent naming responses to it are slower than when it has not been previously ignored (Tipper, S.P., 1985. The negative priming effect: inhibitory priming by ignored objects. Q. J. Exp. Psychol. 37A, 571-590). It is unclear whether this phenomenon arises due to the involvement of abstract semantic representations that the ignored object accesses automatically. Contemporary connectionist models propose a key role for the anterior temporal cortex in the representation of abstract semantic knowledge (e.g., McClelland, J.L., Rogers, T.T., 2003. The parallel distributed processing approach to semantic cognition. Nat. Rev. Neurosci. 4, 310-322), suggesting that this region should be involved during performance of the classic identity NP task if it involves semantic access. Using high-field (4 T) event-related functional magnetic resonance imaging, we observed increased BOLD responses in the left anterolateral temporal cortex including the temporal pole that was directly related to the magnitude of each individual's NP effect, supporting a semantic locus. Additional signal increases were observed in the supplementary eye fields (SEF) and left inferior parietal lobule (IPL).

  15. Barratt Impulsivity in Healthy Adults Is Associated with Higher Gray Matter Concentration in the Parietal Occipital Cortex that Represents Peripheral Visual Field

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    Jaime S. Ide

    2017-05-01

    Full Text Available Impulsivity is a personality trait of clinical importance. Extant research focuses on fronto-striatal mechanisms of impulsivity and how executive functions are compromised in impulsive individuals. Imaging studies employing voxel based morphometry highlighted impulsivity-related changes in gray matter concentrations in a wide array of cerebral structures. In particular, whereas prefrontal cortical areas appear to show structural alterations in individuals with a neuropsychiatric condition, the findings are less than consistent in the healthy population. Here, in a sample (n = 113 of young adults assessed for Barratt impulsivity, we controlled for age, gender and alcohol use, and showed that higher impulsivity score is associated with increased gray matter volume (GMV in bilateral medial parietal and occipital cortices known to represent the peripheral visual field. When impulsivity components were assessed, we observed that this increase in parieto-occipital cortical volume is correlated with inattention and non-planning but not motor subscore. In a separate behavioral experiment of 10 young adults, we demonstrated that impulsive individuals are more vulnerable to the influence of a distractor on target detection in an attention task. If replicated, these findings together suggest aberrant visual attention as a neural correlate of an impulsive personality trait in neurotypical individuals and need to be reconciled with the literature that focuses on frontal dysfunctions.

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. 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.

  1. Specifying the role of the left prefrontal cortex in word selection

    Science.gov (United States)

    Ries, S. K; Karzmark, C. R.; Navarrete, E.; Knight, R. T.; Dronkers, N. F.

    2015-01-01

    Word selection allows us to choose words during language production. This is often viewed as a competitive process wherein a lexical representation is retrieved among semantically-related alternatives. The left prefrontal cortex (LPFC) is thought to help overcome competition for word selection through top-down control. However, whether the LPFC is always necessary for word selection remains unclear. We tested 6 LPFC-injured patients and controls in two picture naming paradigms varying in terms of item repetition. Both paradigms elicited the expected semantic interference effects (SIE), reflecting interference caused by semantically-related representations in word selection. However, LPFC patients as a group showed a larger SIE than controls only in the paradigm involving item repetition. We argue that item repetition increases interference caused by semantically-related alternatives, resulting in increased LPFC-dependent cognitive control demands. The remaining network of brain regions associated with word selection appears to be sufficient when items are not repeated. PMID:26291289

  2. Transcranial direct current stimulation over the left prefrontal cortex increases randomness of choice in instrumental learning.

    Science.gov (United States)

    Turi, Zsolt; Mittner, Matthias; Opitz, Alexander; Popkes, Miriam; Paulus, Walter; Antal, Andrea

    2015-02-01

    There is growing evidence from neuro-computational studies that instrumental learning involves the dynamic interaction of a computationally rigid, low-level striatal and a more flexible, high-level prefrontal component. To evaluate the role of the prefrontal cortex in instrumental learning, we applied anodal transcranial direct current stimulation (tDCS) optimized for the left dorsolateral prefrontal cortex, by using realistic MR-derived finite element model-based electric field simulations. In a study with a double-blind, sham-controlled, repeated-measures design, sixteen male participants performed a probabilistic learning task while receiving anodal and sham tDCS in a counterbalanced order. Compared to sham tDCS, anodal tDCS significantly increased the amount of maladaptive shifting behavior after optimal outcomes during learning when reward probabilities were highly dissociable. Derived parameters of the Q-learning computational model further revealed a significantly increased model parameter that was sensitive to random action selection in the anodal compared to the sham tDCS session, whereas the learning rate parameter was not influenced significantly by tDCS. These results congruently indicate that prefrontal tDCS during instrumental learning increased randomness of choice, possibly reflecting the influence of the cognitive prefrontal component. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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    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.

  4. 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...... responses in invalidly cued trials. After real rTMS, task-related activity of the stimulated left rPMd showed increased task-related coupling with activity in ipsilateral SMG and the adjacent anterior intraparietal area (AIP). Individuals who showed a stronger increase in left-hemispheric premotor...

  5. Light-Emitting Diode (LED) therapy improves occipital cortex damage by decreasing apoptosis and increasing BDNF-expressing cells in methanol-induced toxicity in rats.

    Science.gov (United States)

    Ghanbari, Amir; Ghareghani, Majid; Zibara, Kazem; Delaviz, Hamdallah; Ebadi, Elham; Jahantab, Mohammad Hossein

    2017-05-01

    Methanol-induced retinal toxicity, frequently associated with elevated free radicals and cell edema, is characterized by progressive retinal ganglion cell (RGC) death and vision loss. Previous studies investigated the effect of photomodulation on RGCs, but not the visual cortex. In this study, the effect of 670nm Light-Emitting Diode (LED) therapy on RGCs and visual cortex recovery was investigated in a seven-day methanol-induced retinal toxicity protocol in rats. Methanol administration showed a reduction in the number of RGCs, loss of neurons (neuronal nuclear antigen, NeuN+), activation of glial fibrillary acidic protein (GFAP+) expressing cells, suppression of brain-derived neurotrophic factor (BDNF+) positive cells, increase in apoptosis (caspase 3+) and enhancement of nitric oxide (NO) release in serum and brain. On the other hand, LED therapy significantly reduced RGC death, in comparison to the methanol group. In addition, the number of BDNF positive cells was significantly higher in the visual cortex of LED-treated group, in comparison to methanol-intoxicated and control groups. Moreover, LED therapy caused a significant decrease in cell death (caspase 3+ cells) and a significant reduction in the NO levels, both in serum and brain tissue, in comparison to methanol-intoxicated rats. Overall, LED therapy demonstrated a number of beneficial effects in decreasing oxidative stress and in functional recovery of RGCs and visual cortex. Our data suggest that LED therapy could be a potential condidate as a non-invasive approach for treatment of retinal damage, which needs further clinicl studies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Increased facilitatory connectivity from the pre-SMA to the left dorsal premotor cortex during pseudoword repetition

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Saur, Dorothee; Price, Cathy J

    2013-01-01

    repetition. The optimal model was identified with Bayesian model selection and reflected a network with driving input to pre-SMA and an increase in facilitatory drive from pre-SMA to PMd during repetition of pseudowords. The task-specific increase in effective connectivity from pre-SMA to left PMd suggests......Previous studies have demonstrated that the repetition of pseudowords engages a network of premotor areas for articulatory planning and articulation. However, it remains unclear how these premotor areas interact and drive one another during speech production. We used fMRI with dynamic causal...... were common to repetition in both modalities. We thus obtained three seed regions: the bilateral pre-SMA, left dorsal premotor cortex (PMd), and left ventral premotor cortex that were used to test 63 different models of effective connectivity in the premotor network for pseudoword relative to word...

  7. Generating predictions: lesion evidence on the role of left inferior frontal cortex in rapid syntactic analysis.

    Science.gov (United States)

    Jakuszeit, Maria; Kotz, Sonja A; Hasting, Anna S

    2013-01-01

    A well-documented phenomenon in event-related electroencephalography (EEG) and magnetoencephalography (MEG) studies on language processing is that syntactic violations of different types elicit negativities as early as 100 msec after the violation point. Recently, these responses have been associated with activations in or very close to sensory cortices, suggesting the involvement of basic sensory mechanisms in the detection of syntactic violations. The present study investigated whether intact auditory cortices and adjacent temporal regions are sufficient to generate early syntactic negativities in the auditory event-related potential (ERP). We tested ten clinically non-aphasic patients with left inferior frontal lesions, but intact temporal cortices in a passive auditory ERP paradigm that had reliably elicited early negativities in response to violations of subject-verb agreement and word category in the past. Subject-verb agreement violations failed to elicit early grammaticality effects in these patients, whereas a group of ten age-matched controls showed a reliable early negativity. This finding supports the idea that sensory aspects of syntactic analysis as reflected in early syntactic negativities critically depend on top-down predictions generated by the left inferior frontal cortex. In contrast, word category violations elicited a small, marginally significant early negativity both in controls and patients, suggesting an additional involvement of temporal regions in early phrase structure processing. In an additional auditory oddball experiment patients showed a regular P300, but no N2b component in response to deviant tones, indicating that their deficit in generating sensory predictions extends beyond the language domain. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Giant high occipital encephalocele

    Directory of Open Access Journals (Sweden)

    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.

  9. Visuokinesthetic perception of hand movement is mediated by cerebro-cerebellar interaction between the left cerebellum and right parietal cortex.

    Science.gov (United States)

    Hagura, Nobuhiro; Oouchida, Yutaka; Aramaki, Yu; Okada, Tomohisa; Matsumura, Michikazu; Sadato, Norihiro; Naito, Eiichi

    2009-01-01

    Combination of visual and kinesthetic information is essential to perceive bodily movements. We conducted behavioral and functional magnetic resonance imaging experiments to investigate the neuronal correlates of visuokinesthetic combination in perception of hand movement. Participants experienced illusory flexion movement of their hand elicited by tendon vibration while they viewed video-recorded flexion (congruent: CONG) or extension (incongruent: INCONG) motions of their hand. The amount of illusory experience was graded by the visual velocities only when visual information regarding hand motion was concordant with kinesthetic information (CONG). The left posterolateral cerebellum was specifically recruited under the CONG, and this left cerebellar activation was consistent for both left and right hands. The left cerebellar activity reflected the participants' intensity of illusory hand movement under the CONG, and we further showed that coupling of activity between the left cerebellum and the "right" parietal cortex emerges during this visuokinesthetic combination/perception. The "left" cerebellum, working with the anatomically connected high-order bodily region of the "right" parietal cortex, participates in online combination of exteroceptive (vision) and interoceptive (kinesthesia) information to perceive hand movement. The cerebro-cerebellar interaction may underlie updating of one's "body image," when perceiving bodily movement from visual and kinesthetic information.

  10. 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

    Directory of Open Access Journals (Sweden)

    Andrea I. Costantino

    2017-11-01

    Full Text Available 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.

  11. 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.

  12. Enhanced early-latency electromagnetic activity in the left premotor cortex is associated with successful phonetic categorization.

    Science.gov (United States)

    Alho, Jussi; Sato, Marc; Sams, Mikko; Schwartz, Jean-Luc; Tiitinen, Hannu; Jääskeläinen, Iiro P

    2012-05-01

    Sensory-motor interactions between auditory and articulatory representations in the dorsal auditory processing stream are suggested to contribute to speech perception, especially when bottom-up information alone is insufficient for purely auditory perceptual mechanisms to succeed. Here, we hypothesized that the dorsal stream responds more vigorously to auditory syllables when one is engaged in a phonetic identification/repetition task subsequent to perception compared to passive listening, and that this effect is further augmented when the syllables are embedded in noise. To this end, we recorded magnetoencephalography while twenty subjects listened to speech syllables, with and without noise masking, in four conditions: passive perception; overt repetition; covert repetition; and overt imitation. Compared to passive listening, left-hemispheric N100m equivalent current dipole responses were amplified and shifted posteriorly when perception was followed by covert repetition task. Cortically constrained minimum-norm estimates showed amplified left supramarginal and angylar gyri responses in the covert repetition condition at ~100ms from stimulus onset. Longer-latency responses at ~200ms were amplified in the covert repetition condition in the left angular gyrus and in all three active conditions in the left premotor cortex, with further enhancements when the syllables were embedded in noise. Phonetic categorization accuracy and magnitude of voice pitch change between overt repetition and imitation conditions correlated with left premotor cortex responses at ~100 and ~200ms, respectively. Together, these results suggest that the dorsal stream involvement in speech perception is dependent on perceptual task demands and that phonetic categorization performance is influenced by the left premotor cortex. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Speech dynamics are coded in the left motor cortex in fluent speakers but not in adults who stutter.

    Science.gov (United States)

    Neef, Nicole E; Hoang, T N Linh; Neef, Andreas; Paulus, Walter; Sommer, Martin

    2015-03-01

    The precise excitability regulation of neuronal circuits in the primary motor cortex is central to the successful and fluent production of speech. Our question was whether the involuntary execution of undesirable movements, e.g. stuttering, is linked to an insufficient excitability tuning of neural populations in the orofacial region of the primary motor cortex. We determined the speech-related time course of excitability modulation in the left and right primary motor tongue representation. Thirteen fluent speakers (four females, nine males; aged 23-44) and 13 adults who stutter (four females, nine males, aged 21-55) were asked to build verbs with the verbal prefix 'auf'. Single-pulse transcranial magnetic stimulation was applied over the primary motor cortex during the transition phase between a fixed labiodental articulatory configuration and immediately following articulatory configurations, at different latencies after transition onset. Bilateral electromyography was recorded from self-adhesive electrodes placed on the surface of the tongue. Off-line, we extracted the motor evoked potential amplitudes and normalized these amplitudes to the individual baseline excitability during the fixed configuration. Fluent speakers demonstrated a prominent left hemisphere increase of motor cortex excitability in the transition phase (P = 0.009). In contrast, the excitability of the right primary motor tongue representation was unchanged. Interestingly, adults afflicted with stuttering revealed a lack of left-hemisphere facilitation. Moreover, the magnitude of facilitation was negatively correlated with stuttering frequency. Although orofacial midline muscles are bilaterally innervated from corticobulbar projections of both hemispheres, our results indicate that speech motor plans are controlled primarily in the left primary speech motor cortex. This speech motor planning-related asymmetry towards the left orofacial motor cortex is missing in stuttering. Moreover, a negative

  14. 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 ...... 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.......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...... asked to covertly prepare motor responses as indicated by a directional cue presented 1 s before the target. On 20% of trials, the cue was invalid, requiring subjects to readjust their motor plan according to the target location. Compared with sham rTMS, real rTMS increased the number of correct...

  15. Visuokinesthetic Perception of Hand Movement is Mediated by Cerebro–Cerebellar Interaction between the Left Cerebellum and Right Parietal Cortex

    Science.gov (United States)

    Hagura, Nobuhiro; Oouchida, Yutaka; Aramaki, Yu; Okada, Tomohisa; Matsumura, Michikazu; Sadato, Norihiro

    2009-01-01

    Combination of visual and kinesthetic information is essential to perceive bodily movements. We conducted behavioral and functional magnetic resonance imaging experiments to investigate the neuronal correlates of visuokinesthetic combination in perception of hand movement. Participants experienced illusory flexion movement of their hand elicited by tendon vibration while they viewed video-recorded flexion (congruent: CONG) or extension (incongruent: INCONG) motions of their hand. The amount of illusory experience was graded by the visual velocities only when visual information regarding hand motion was concordant with kinesthetic information (CONG). The left posterolateral cerebellum was specifically recruited under the CONG, and this left cerebellar activation was consistent for both left and right hands. The left cerebellar activity reflected the participants' intensity of illusory hand movement under the CONG, and we further showed that coupling of activity between the left cerebellum and the “right” parietal cortex emerges during this visuokinesthetic combination/perception. The “left” cerebellum, working with the anatomically connected high-order bodily region of the “right” parietal cortex, participates in online combination of exteroceptive (vision) and interoceptive (kinesthesia) information to perceive hand movement. The cerebro–cerebellar interaction may underlie updating of one's “body image,” when perceiving bodily movement from visual and kinesthetic information. PMID:18453537

  16. Awake perimetry testing for occipital epilepsy surgery.

    Science.gov (United States)

    Joswig, Holger; Girvin, John P; Blume, Warren T; Burneo, Jorge G; Steven, David A

    2017-12-08

    In the literature, there are few reports that provide a detailed account on the technique of visual electrocortical stimulation in the setting of resective surgery for occipital epilepsy. In this technical note, the authors describe how a 26-year-old male with long-standing occipital epilepsy underwent resective surgery under awake conditions, using electrocortical stimulation of the occipital lobe, with the aid of a laser pointer and a perimetry chart on a stand within his visual field. The eloquent primary visual cortex was found to overlap with the seizure onset zone that was previously determined with subdural electrodes. A maximum functionally safe resection was performed, rendering the patient seizure free as of his last follow-up at 20 months, with no visual field impairment.

  17. The left frontal cortex supports reserve in aging by enhancing functional network efficiency.

    Science.gov (United States)

    Franzmeier, Nicolai; Hartmann, Julia; Taylor, Alexander N W; Araque-Caballero, Miguel Á; Simon-Vermot, Lee; Kambeitz-Ilankovic, Lana; Bürger, Katharina; Catak, Cihan; Janowitz, Daniel; Müller, Claudia; Ertl-Wagner, Birgit; Stahl, Robert; Dichgans, Martin; Duering, Marco; Ewers, Michael

    2018-03-06

    Recent evidence derived from functional magnetic resonance imaging (fMRI) studies suggests that functional hubs (i.e., highly connected brain regions) are important for mental health. We found recently that global connectivity of a hub in the left frontal cortex (LFC connectivity) is associated with relatively preserved memory abilities and higher levels of protective factors (education, IQ) in normal aging and Alzheimer's disease. These results suggest that LFC connectivity supports reserve capacity, alleviating memory decline. An open question, however, is why LFC connectivity is beneficial and supports memory function in the face of neurodegeneration. We hypothesized that higher LFC connectivity is associated with enhanced efficiency in connected major networks involved in episodic memory. We further hypothesized that higher LFC-related network efficiency predicts higher memory abilities. We assessed fMRI during a face-name association learning task performed by 26 healthy, cognitively normal elderly participants. Using beta-series correlation analysis, we computed task-related LFC connectivity to key memory networks, including the default mode network (DMN) and dorsal attention network (DAN). Network efficiency within the DMN and DAN was estimated by the graph theoretical small-worldness statistic. We applied linear regression analyses to test the association between LFC connectivity with the DMN/DAN and small-worldness of these networks. Mediation analysis was applied to test LFC connectivity to the DMN and DAN as a mediator of the association between education and higher DMN and DAN small-worldness. Last, we tested network small-worldness as a predictor of memory performance. We found that higher LFC connectivity to the DMN and DAN during successful memory encoding and recognition was associated with higher small-worldness of those networks. Higher task-related LFC connectivity mediated the association between education and higher small-worldness in the DMN

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. cTBS delivered to the left somatosensory cortex changes its functional connectivity during rest

    NARCIS (Netherlands)

    Valchev, Nikola; Curcic-Blake, Branisalava; Renken, Remco J.; Avenanti, Alessio; Keysers, Christian; Gazzola, Valeria; Maurits, Natasha M.

    2015-01-01

    The primary somatosensory cortex (SI) plays a critical role in somatosensation as well as in action performance and social cognition. Although the SI has been a major target of experimental and clinical research using non-invasive transcranial magnetic stimulation (TMS), to date information on the

  4. Inactivation of the left auditory cortex impairs temporal discrimination in the rat

    Czech Academy of Sciences Publication Activity Database

    Rybalko, Natalia; Šuta, Daniel; Popelář, Jiří; Syka, Josef

    2010-01-01

    Roč. 209, č. 1 (2010), s. 123-130 ISSN 0166-4328 R&D Projects: GA ČR GA309/07/1336; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390512 Keywords : auditory cortex * temporal discrimination * hemispheric lateralization Subject RIV: FH - Neurology Impact factor: 3.393, year: 2010

  5. 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

  6. Motion verb sentences activate left posterior middle temporal cortex despite static context

    DEFF Research Database (Denmark)

    Wallentin, M; Ellegaard Lund, Torben; Østergaard, Svend

    2005-01-01

    The left posterior middle temporal region, anterior to V5/MT, has been shown to be responsive both to images with implied motion, to simulated motion, and to motion verbs. In this study, we investigated whether sentence context alters the response of the left posterior middle temporal region....... 'Fictive motion' sentences are sentences in which an inanimate subject noun, semantically incapable of self movement, is coupled with a motion verb, yielding an apparent semantic contradiction (e.g. 'The path comes into the garden.'). However, this context yields no less activation in the left posterior...... middle temporal region than sentences in which the motion can be applied to the subject noun. We speculate that the left posterior middle temporal region activity in fictive motion sentences reflects the fact that the hearer applies motion to the depicted scenario by scanning it egocentrically...

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Left dorsolateral prefrontal cortex atrophy is associated with frontal lobe function in Alzheimer's disease and contributes to caregiver burden.

    Science.gov (United States)

    Matsuoka, Kiwamu; Yasuno, Fumihiko; Hashimoto, Akiko; Miyasaka, Toshiteru; Takahashi, Masato; Kiuchi, Kuniaki; Iida, Junzo; Kichikawa, Kimihiko; Kishimoto, Toshifumi

    2017-12-27

    Caregivers of patients with dementia experience physical and mental deterioration. We have previously reported a correlation between caregiver burden and the Frontal Assessment Battery (FAB) total scores of patients with Alzheimer's disease (AD), especially regarding the dependency factor from the Zarit Burden Interview. The present study aimed to identify an objective biomarker for predicting caregiver burden. The participants were 26 pairs of caregivers and patients with AD and mild-to-moderate dementia. Correlations between regional gray matter volumes in the patients with AD and the FAB total scores were explored by using whole-brain voxel-based morphometric analysis. Path analysis was used to estimate the relationships between regional gray matter volumes, FAB total scores, and caregiver burden based on the Zarit Burden Interview. The voxel-based morphometric revealed a significant positive correlation between the FAB total scores and the volume of the left dorsolateral prefrontal cortex. This positive correlation persisted after controlling for the effect of general cognitive dysfunction, which was assessed by using the Mini-Mental State Examination. Path analysis revealed that decreases in FAB scores, caused by reduced frontal lobe volumes, negatively affected caregiver burden. The present study revealed that frontal lobe function, based on FAB scores, was affected by the volume of the left dorsolateral prefrontal cortex. Decreased scores were associated with greater caregiver burden, especially for the dependency factor. These findings may facilitate the development of an objective biomarker for predicting caregiver burden. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Differential effects of continuous theta burst stimulation over left premotor cortex and right prefrontal cortex on modulating upper limb somatosensory input.

    Science.gov (United States)

    Brown, Matt J N; Staines, W Richard

    2016-02-15

    Somatosensory evoked potentials (SEPs) represent somatosensory processing in non-primary motor areas (i.e. frontal N30 and N60) and somatosensory cortices (i.e. parietal P50). It is well-known that the premotor cortex (PMC) and prefrontal cortex (PFC) are involved in the preparation and planning of upper limb movements but it is currently unclear how they modulate somatosensory processing for upper limb motor control. In the current study, two experiments examined SEP modulations after continuous theta burst stimulation (cTBS) was used to transiently disrupt the left PMC (Experiment 1) and right PFC (Experiment 2). Both Experiment 1 (n=15) and Experiment 2 (n=16) used pre-post experimental designs. In both experiments participants performed a task requiring detection of varying amplitudes of attended vibrotactile (VibT) stimuli to the left index finger (D2) and execution of a pre-matched finger sequence with the right (contralateral) hand to specific VibT targets. During the task, SEPs were measured to median nerve (MN) stimulations time-locked during pre-stimulus (250 ms before VibT), early response selection (250 ms after VibT), late preparatory (750 ms after VibT) and execution (1250 ms VibT) phases. The key findings of Experiment 1 revealed significant decreases in N30 and N60 peak amplitudes after cTBS to PMC. In contrast, the results of Experiment 2, also found significant decreased N60 peak amplitudes as well as trends for increased N30 and P50 peak amplitudes. A direct comparison of Experiment 1 and Experiment 2 confirmed differential modulation of N30 peak amplitudes after PMC (gated) compared to PFC (enhanced) cTBS. Collectively, these results support that both the left PMC and right PFC have modulatory roles on early somatosensory input into non-primary motor areas, such as PMC and supplementary motor area (SMA), represented by frontal N30 and N60 SEPs. These results confirm that PMC and PFC are both part of a network that regulates somatosensory input

  10. Multimodal connectivity mapping of the human left anterior and posterior lateral prefrontal cortex.

    Science.gov (United States)

    Reid, Andrew T; Bzdok, Danilo; Langner, Robert; Fox, Peter T; Laird, Angela R; Amunts, Katrin; Eickhoff, Simon B; Eickhoff, Claudia R

    2016-06-01

    Working memory is essential for many of our distinctly human abilities, including reasoning, problem solving, and planning. Research spanning many decades has helped to refine our understanding of this high-level function as comprising several hierarchically organized components, some which maintain information in the conscious mind, and others which manipulate and reorganize this information in useful ways. In the neocortex, these processes are likely implemented by a distributed frontoparietal network, with more posterior regions serving to maintain volatile information, and more anterior regions subserving the manipulation of this information. Recent meta-analytic findings have identified the anterior lateral prefrontal cortex, in particular, as being generally engaged by working memory tasks, while the posterior lateral prefrontal cortex was more strongly associated with the cognitive load required by these tasks. These findings suggest specific roles for these regions in the cognitive control processes underlying working memory. To further characterize these regions, we applied three distinct seed-based methods for determining cortical connectivity. Specifically, we employed meta-analytic connectivity mapping across task-based fMRI experiments, resting-state BOLD correlations, and VBM-based structural covariance. We found a frontoparietal pattern of convergence which strongly resembled the working memory networks identified in previous research. A contrast between anterior and posterior parts of the lateral prefrontal cortex revealed distinct connectivity patterns consistent with the idea of a hierarchical organization of frontoparietal networks. Moreover, we found a distributed network that was anticorrelated with the anterior seed region, which included most of the default mode network and a subcomponent related to social and emotional processing. These findings fit well with the internal attention model of working memory, in which representation of

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

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    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.

  12. Facilitating memory for novel characters by reducing neural repetition suppression in the left fusiform cortex.

    Science.gov (United States)

    Xue, Gui; Mei, Leilei; Chen, Chuansheng; Lu, Zhong-Lin; Poldrack, Russell A; Dong, Qi

    2010-10-06

    The left midfusiform and adjacent regions have been implicated in processing and memorizing familiar words, yet its role in memorizing novel characters has not been well understood. Using functional MRI, the present study examined the hypothesis that the left midfusiform is also involved in memorizing novel characters and spaced learning could enhance the memory by enhancing the left midfusiform activity during learning. Nineteen native Chinese readers were scanned while memorizing the visual form of 120 Korean characters that were novel to the subjects. Each character was repeated four times during learning. Repetition suppression was manipulated by using two different repetition schedules: massed learning and spaced learning, pseudo-randomly mixed within the same scanning session. Under the massed learning condition, the four repetitions were consecutive (with a jittered inter-repetition interval to improve the design efficiency). Under the spaced learning condition, the four repetitions were interleaved with a minimal inter-repetition lag of 6 stimuli. Spaced learning significantly improved participants' performance during the recognition memory test administered one hour after the scan. Stronger left midfusiform and inferior temporal gyrus activities during learning (summed across four repetitions) were associated with better memory of the characters, based on both within- and cross-subjects analyses. Compared to massed learning, spaced learning significantly reduced neural repetition suppression and increased the overall activities in these regions, which were associated with better memory for novel characters. These results demonstrated a strong link between cortical activity in the left midfusiform and memory for novel characters, and thus challenge the visual word form area (VWFA) hypothesis. Our results also shed light on the neural mechanisms of the spacing effect in memorizing novel characters.

  13. Excitability changes in the left primary motor cortex innervating the hand muscles induced during speech about hand or leg movements.

    Science.gov (United States)

    Onmyoji, Yusuke; Kubota, Shinji; Hirano, Masato; Tanaka, Megumi; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-05-06

    In the present study, we used transcranial magnetic stimulation (TMS) to investigate the changes in the excitability of the left primary motor cortex (M1) innervating the hand muscles and in short-interval intracortical inhibition (SICI) during speech describing hand or leg movements. In experiment 1, we investigated the effects of the contents of speech on the amplitude of the motor evoked potentials (MEPs) induced during reading aloud and silent reading. In experiment 2, we repeated experiment 1 with an additional condition, the non-vocal oral movement (No-Voc OM) condition, and investigated the change in SICI induced in each condition using the paired TMS paradigm. The MEP observed in the reading aloud and No-Voc OM conditions exhibited significantly greater amplitudes than those seen in the silent reading conditions, irrespective of the content of the sentences spoken by the subjects or the timing of the TMS. There were no significant differences in SICI between the experimental conditions. Our findings suggest that the increased excitability of the left M1 hand area detected during speech was mainly caused by speech-related oral movements and the activation of language processing-related brain functions. The increased left M1 excitability was probably also mediated by neural mechanisms other than reduced SICI; i.e., disinhibition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Early (n170/m170) face-sensitivity despite right lateral occipital brain damage in acquired prosopagnosia.

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    Prieto, Esther Alonso; Caharel, Stéphanie; Henson, Richard; Rossion, Bruno

    2011-01-01

    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"), 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"). These results were replicated by a magnetoencephalographic 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 the N170 effect.

  15. 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.

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

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    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.

  17. 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.

  18. 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.

  19. 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.

  20. Assessment of Anterior Cingulate Cortex (ACC and Left Cerebellar Metabolism in Asperger's Syndrome with Proton Magnetic Resonance Spectroscopy (MRS.

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    Aya Goji

    Full Text Available Proton magnetic resonance spectroscopy (1H MRS is a noninvasive neuroimaging method to quantify biochemical metabolites in vivo and it can serve as a powerful tool to monitor neurobiochemical profiles in the brain. Asperger's syndrome (AS is a type of autism spectrum disorder, which is characterized by impaired social skills and restrictive, repetitive patterns of interest and activities, while intellectual levels and language skills are relatively preserved. Despite clinical aspects have been well-characterized, neurometabolic profiling in the brain of AS remains to be clear. The present study used proton magnetic resonance spectroscopy (1H MRS to investigate whether pediatric AS is associated with measurable neurometabolic abnormalities that can contribute new information on the neurobiological underpinnings of the disorder.Study participants consisted of 34 children with AS (2-12 years old; mean age 5.2 (±2.0; 28 boys and 19 typically developed children (2-11 years old; mean age 5.6 (±2.6; 12 boys who served as the normal control group. The 1H MRS data were obtained from two regions of interest: the anterior cingulate cortex (ACC and left cerebellum.In the ACC, levels of N-acetylaspartate (NAA, total creatine (tCr, total choline-containing compounds (tCho and myo-Inositol (mI were significantly decreased in children with AS compared to controls. On the other hand, no significant group differences in any of the metabolites were found in the left cerebellum. Neither age nor sex accounted for the metabolic findings in the regions.The finding of decreased levels of NAA, tCr, tCho, and mI in the ACC but not in left cerebellar voxels in the AS, suggests a lower ACC neuronal density in the present AS cohort compared to controls.

  1. 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.

    Science.gov (United States)

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

    2015-10-15

    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.

  2. 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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26501256

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

    Science.gov (United States)

    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

  4. Increased Low-Frequency Resting-State Brain Activity by High-Frequency Repetitive TMS on the Left Dorsolateral Prefrontal Cortex.

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    Xue, Shao-Wei; Guo, Yonghu; Peng, Wei; Zhang, Jian; Chang, Da; Zang, Yu-Feng; Wang, Ze

    2017-01-01

    Beneficial effects of repetitive transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) have been consistently shown for treating various neuropsychiatrical or neuropsychological disorders, but relatively little is known about its neural mechanisms. Here we conducted a randomized, double-blind, SHAM-controlled study to assess the effects of high-frequency left DLPFC rTMS on resting-state activity. Thirty-eight young healthy subjects received two sessions of either real rTMS ( N = 18, 90% motor-threshold; left DLPFC at 20 Hz) or SHAM TMS ( N = 20) and functional magnetic resonance imaging scan during rest in 2 days separated by 48 h. Resting-state bran activity was measured with the fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC). Increased fALFF was found in rostral anterior cingulate cortex (rACC) after 20 Hz rTMS, while no changes were observed after SHAM stimulation. Using the suprathreshold rACC cluster as the seed, increased FC was found in left temporal cortex (stimulation vs. group interaction). These data suggest that high-frequency rTMS on left DLPFC enhances low-frequency resting-state brain activity in the target site and remote sites as reflected by fALFF and FC.

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

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    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.

  6. Contribution of writing to reading: Dissociation between cognitive and motor process in the left dorsal premotor cortex.

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    Pattamadilok, Chotiga; Ponz, Aurélie; Planton, Samuel; Bonnard, Mireille

    2016-04-01

    Functional brain imaging studies reported activation of the left dorsal premotor cortex (PMd), that is, a main area in the writing network, in reading tasks. However, it remains unclear whether this area is causally relevant for written stimulus recognition or its activation simply results from a passive coactivation of reading and writing networks. Here, we used chronometric paired-pulse transcranial magnetic stimulation (TMS) to address this issue by disrupting the activity of the PMd, the so-called Exner's area, while participants performed a lexical decision task. Both words and pseudowords were presented in printed and handwritten characters. The latter was assumed to be closely associated with motor representations of handwriting gestures. We found that TMS over the PMd in relatively early time-windows, i.e., between 60 and 160 ms after the stimulus onset, increased reaction times to pseudoword without affecting word recognition. Interestingly, this result pattern was found for both printed and handwritten characters, that is, regardless of whether the characters evoked motor representations of writing actions. Our result showed that under some circumstances the activation of the PMd does not simply result from passive association between reading and writing networks but has a functional role in the reading process. At least, at an early stage of written stimuli recognition, this role seems to depend on a common sublexical and serial process underlying writing and pseudoword reading rather than on an implicit evocation of writing actions during reading as typically assumed. © 2016 Wiley Periodicals, Inc.

  7. Affective emotion increases heart rate variability and activates left dorsolateral prefrontal cortex in post-traumatic growth.

    Science.gov (United States)

    Wei, Chuguang; Han, Jin; Zhang, Yuqing; Hannak, Walter; Dai, Yanyan; Liu, Zhengkui

    2017-11-30

    The present study evaluated the activities of heart rate variability (HRV) and dorsolateral prefrontal cortex (DLPFC) in response to the presentation of affective pictures correlated with posttraumatic growth (PTG) among adults exposed to the Tianjin explosion incident. The participants who were directly involved in the Tianjin explosions were divided into control, post-traumatic stress disorder (PTSD) and PTG group according to the scores of PTSD Checklist-Civilian Version and PTG Inventory survey. All participants received exposure to affective images. Electrocardiogram recording took place during the process for the purpose of analyzing HRV. Meanwhile, functional near-infrared spectroscopy (fNIRS) was used to measure DLPFC activity through hemodynamic response. Our results indicated that, while performing the negative and positive picture stimulating, PTG increased both in low and high frequency components of HRV compared with the control group, but PTSD was not observed in this phenomenon. Moreover, the fNIRS data revealed that PTG had an increased activation in the left DLPFC compared to the control in the condition of negative pictures stimulating, wheras PTSD showed a higher activation in the right DLPFC while receiving positive pictures stimulating. To our knowledge, this is the first study which provides the differences between PTSD and PTG in emotional regulation.

  8. 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.)

  9. Effects of 10 Hz Repetitive Transcranial Magnetic Stimulation of the Left Dorsolateral Prefrontal Cortex in Disorders of Consciousness

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    Xiaoyu Xia

    2017-05-01

    Full Text Available BackgroundWhile repetitive transcranial magnetic stimulation (rTMS has been applied in treatment of patients with disorders of consciousness (DOC, a standardized stimulation protocol has not been proposed, and its therapeutic effects are inconsistently documented.ObjectivesTo assess the efficacy of rTMS in improving consciousness in patients with persistent minimally conscious state (MCS or unresponsive wakefulness syndrome (UWS, previously known as vegetative state (VS.MethodA prospective single-blinded study, with selected subjects, was carried out. In total, 16 patients (5 MCS and 11 VS/UWS with chronic DOC were included. All patients received active 10 Hz rTMS at the left dorsolateral prefrontal cortex (DLPFC, at one session per day, for 20 consecutive days. A single daily session of stimulation consisted of 1,000 pulses (10 s of 10 Hz trains; repeated 10 times with an inter-train interval of 60 s; and 11 min and 40 s for total session. The main outcome measures were changes in the total score on the JFK Coma Recovery Scale-Revised (CRS-R scale. Additional measures were the impressions of caregivers after the conclusion of the interventions, which were assessed using the Clinical Global Impression-Improvement (CGI-I scale.ResultsThe CRS-R scores were increased in all 5 MCS patients and 4 of 11 VS/UWS patients, while a significant enhancement of CRS-R scores was observed compared to the baseline in all participants (p = 0.007. However, the improvement was more notable in MCS patients (p = 0.042 than their VS/UWS counterparts (p = 0.066. Based on the CGI-I scores, two patients improved considerably, two improved, six minimally improved, six experienced no change, and none deteriorated. Good concordance was seen between the CGI-I result and the increases in CRS-R scores.ConclusionTreatment of 10 Hz multisession rTMS applied to the left DLPFC is promising for the rehabilitation of DOC patients, especially those in MCS

  10. 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...... 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....... Stimulus–response curves were constructed by recording the intensity of the reported phosphenes evoked in the contralateral visual field at range of TMS intensities. Phosphene measurements revealed that MD produced a rapid and robust decrease in cortical excitability relative to a control condition without...

  11. Optimal trajectory for the occipital condyle screw.

    Science.gov (United States)

    Le, Tien V; Vivas, Andrew C; Baaj, Ali A; Vale, Fernando L; Uribe, Juan S

    2014-04-01

    Retrospective analysis. To understand what may constitute an optimal trajectory for an occipital condyle (OC) screw. OC screws are an alternative to standard occipital plates as a cephalad fixation point in occipitocervical fusion. An optimal trajectory for placement of OC screws has not been described. We conducted a computed tomography-based study of 340 human occipital condyls. All computed tomographies were negative for traumatic, degenerative, and neoplastic pathology. On the basis of the current literature, linear measurements of distances were made based on a constant entry point. Medial angulations of 10, 20, and 25 degrees relative to the sagittal midline were used. In addition, 10-, 5-degree cranial, 10- and 30-degree caudal angulations were studied to evaluate the incidence of hypoglossal canal and atlantooccipital joint compromise. Average distances were 17.1±2.8, 20.4±2.8, and 22.2±2.9 for 10, 20, and 25 degrees of medial angulation, respectively. Right-sided and left-sided measurements for each category were not significantly different. However, the difference in the measured distances between 10 versus 20 degrees, 10 versus 25 degrees, and 20 versus 25 degrees was all significantly different (PAtlantooccipital joint compromise incidence was 21.8% and 99.1% for 10- and 30-degree caudal angulation, respectively. The condylar entry point should be medial to the condylar fossa, midcondylar, and ≥2 mm caudal to the skull base. An optimal trajectory for the OC screw should have a medial angulation of ≥20 degrees relative to the sagittal midline, trying to stay parallel to the skull base. Minor adjustments in angulation can be made, but any adjustment approaching 10 degrees cranial or caudal leads to an increased risk of hypoglossal canal cranially or atlantooccipital joint compromise caudally.

  12. 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).

  13. 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

  14. Different distal-proximal movement balances in right- and left-hand writing may hint at differential premotor cortex involvement

    NARCIS (Netherlands)

    Potgieser, A. R. E.; de Jong, B. M.

    2011-01-01

    Right-handed people generally write with their right hand. Language expressed in script is thus performed with the hand also preferred for skilled motor tasks. This may suggest an efficient functional interaction between the language area of Broca and the adjacent ventral premotor cortex (PMv) in

  15. Aggravation of symptomatic occipital epilepsy of childhood by carbamazepine

    Directory of Open Access Journals (Sweden)

    Škrijelj Fadil E.

    2014-01-01

    Full Text Available Introduction. Carbamazepine can lead to aggravation of epileptic seizures in generalized epilepsies (primary or secondary with clinical manifestations of absence (typical or atypical and/or myoclonic seizures. However, some focal epilepsies can be also aggravated by the introduction of carbamazepine. Case report. We presented a 10-year-old boy born after a complicated and prolonged delivery completed by vacuum extraction, of early psychomotor development within normal limits. At the age of 8 years he had the first epileptic seizure of simple occipital type with generalization and urination. Brain magnetic resonance imaging (MRI showed focal cortical reductions in the left parietal and occipital regions. Interictal EEG recorded slowed basic activities above the posterior regions of the left hemisphere, with intermittent occurrence of occipital sharp waves and bioccipital sharp and slow-wave complexes. Initially, treatment with valproate was administered; however, the addition of carbamazepine into therapy induced aggravation of seizures and EEG findings, changed behavior and poor performance at school. By withdrawal of carbamazepine the condition improved both clinically and in EEG findings. Conclusion. Childhood occipital epilepsy lesions show deterioration due to carbamazepine, which if administered induces aggravation of seizures, behavior changes, cognition with occurrence of long-term bilateral discharges, and posterior sharp and slow wave high amplitude complexes recorded by EEG.

  16. Organization of cortico-cortical pathways supporting memory retrieval across subregions of the left ventrolateral prefrontal cortex.

    Science.gov (United States)

    Barredo, Jennifer; Verstynen, Timothy D; Badre, David

    2016-09-01

    Functional magnetic resonance imaging (fMRI) evidence indicates that different subregions of ventrolateral prefrontal cortex (VLPFC) participate in distinct cortical networks. These networks have been shown to support separable cognitive functions: anterior VLPFC [inferior frontal gyrus (IFG) pars orbitalis] functionally correlates with a ventral fronto-temporal network associated with top-down influences on memory retrieval, while mid-VLPFC (IFG pars triangularis) functionally correlates with a dorsal fronto-parietal network associated with postretrieval control processes. However, it is not known to what extent subregional differences in network affiliation and function are driven by differences in the organization of underlying white matter pathways. We used high-angular-resolution diffusion spectrum imaging and functional connectivity analysis in unanesthetized humans to address whether the organization of white matter connectivity differs between subregions of VLPFC. Our results demonstrate a ventral-dorsal division within IFG. Ventral IFG as a whole connects broadly to lateral temporal cortex. Although several different individual white matter tracts form connections between ventral IFG and lateral temporal cortex, functional connectivity analysis of fMRI data indicates that these are part of the same ventral functional network. By contrast, across subdivisions, dorsal IFG was connected with the midfrontal gyrus and correlated as a separate dorsal functional network. These qualitative differences in white matter organization within larger macroanatomical subregions of VLPFC support prior functional distinctions among these regions observed in task-based and functional connectivity fMRI studies. These results are consistent with the proposal that anatomical connectivity is a crucial determinant of systems-level functional organization of frontal cortex and the brain in general. Copyright © 2016 the American Physiological Society.

  17. 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

  18. 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.

  19. Left and right High Frequency repetitive Transcranial Magnetic Stimulation of the dorsolateral prefrontal cortex does not affect mood in female volunteers.

    Science.gov (United States)

    Baeken, C; Leyman, L; De Raedt, R; Vanderhasselt, M A; D'haenen, H

    2008-03-01

    High Frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) has yielded divergent results concerning its effect on mood in normal volunteers. In a former study, we were unable to demonstrate negative mood effects after one session of HF-rTMS on the left dorsolateral prefrontal cortex (DLPFC) in a large group of healthy female volunteers: researchers had focused mainly on negative mood changes, overlooking a possible positive mood induction, while no studies had yet examined mood effects of HF-rTMS delivered on the right prefrontal cortex. In this study, we have tried to replicate our previous HF-rTMS findings on the left DLPFC in a new (large) group of healthy female subjects, and we focused especially on positive mood changes. We also extended our former research by stimulating the right DLPFC in a different but comparable (large) group of healthy female volunteers with the same HF-rTMS parameters. In this sham-controlled, single blind, crossover HF-rTMS study, stimulus parameters were an exact copy of our previous healthy volunteer study. To exclude individual anatomical differences, the left and right DLPFC were targeted under magnetic resonance (MRI) guidance. To examine subjective mood changes we used Visual Analogue Scales (VAS), the Profile of Mood States (POMS), and the Positive Affect and Negative Affect Schedule (PANAS), the latter to assure assessment of positive emotions. To detect any delayed mood changes, assessments were also re-administered 30min post-HF-rTMS. We were unable to demonstrate immediate or delayed mood changes after one single active HF-rTMS session on the left or right DLPFC. Although we took into account several methodological problems which might have confounded previous rTMS mood induction studies, the hypothesis that one single session of HF-rTMS on the left or on the right DLPFC can influence mood in healthy female volunteers was not supported. One HF-rTMS session has no effect on subjective mood in healthy female

  20. At-home tDCS of the left dorsolateral prefrontal cortex improves visual short-term memory in mild vascular dementia.

    Science.gov (United States)

    André, Sebastian; Heinrich, Simon; Kayser, Friederike; Menzler, Katja; Kesselring, Jürg; Khader, Patrick H; Lefaucheur, Jean-Pascal; Mylius, Veit

    2016-10-15

    Previous studies have shown that anodal transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex (DLPFC) led to an improvement of various cognitive functions in patients with Alzheimer dementia, early affected by short-term memory deficits. Since this approach has not been evaluated in the context of vascular dementia, which rather affects the velocity of cognitive responses, we aimed at improving these functions by applying repetitive sessions of anodal tDCS. Four 20-minute sessions of 2mA anodal or sham at-home tDCS were applied to the left DLPFC in a single-blinded randomised study of 21 patients with mild vascular dementia, with parallel-group design. The effect of tDCS on cognitive testing was assessed up to two weeks beyond the stimulation time. A similar clinically meaningful improvement of various cognitive and behavioral dysfunction characteristics could be observed following either active or sham tDCS, whereas visual recall, and reaction times in the n-back task as well as in the go/no-go test improved only in the active tDCS group. In patients with mild vascular dementia, anodal tDCS of the left DLPFC is able to produce additional effects to cognitive training on visual short-term memory, verbal working memory, and executive control. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. You talkin' to me? Communicative talker gaze activates left-lateralized superior temporal cortex during perception of degraded speech.

    Science.gov (United States)

    McGettigan, Carolyn; Jasmin, Kyle; Eisner, Frank; Agnew, Zarinah K; Josephs, Oliver J; Calder, Andrew J; Jessop, Rosemary; Lawson, Rebecca P; Spielmann, Mona; Scott, Sophie K

    2017-06-01

    Neuroimaging studies of speech perception have consistently indicated a left-hemisphere dominance in the temporal lobes' responses to intelligible auditory speech signals (McGettigan and Scott, 2012). However, there are important communicative cues that cannot be extracted from auditory signals alone, including the direction of the talker's gaze. Previous work has implicated the superior temporal cortices in processing gaze direction, with evidence for predominantly right-lateralized responses (Carlin & Calder, 2013). The aim of the current study was to investigate whether the lateralization of responses to talker gaze differs in an auditory communicative context. Participants in a functional MRI experiment watched and listened to videos of spoken sentences in which the auditory intelligibility and talker gaze direction were manipulated factorially. We observed a left-dominant temporal lobe sensitivity to the talker's gaze direction, in which the left anterior superior temporal sulcus/gyrus and temporal pole showed an enhanced response to direct gaze - further investigation revealed that this pattern of lateralization was modulated by auditory intelligibility. Our results suggest flexibility in the distribution of neural responses to social cues in the face within the context of a challenging speech perception task. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. 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

  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. Clinico-anatomical correlations of left posterior cerebral artery occlusion. Alexia without agraphia, color anomia, and memory disturbance

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-11-01

    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.).

  5. 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.

  6. 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.

  7. 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.

  8. Cortex-sparing fiber dissection: an improved method for the study of white matter anatomy in the human brain

    Science.gov (United States)

    Martino, Juan; De Witt Hamer, Philip C; Vergani, Francesco; Brogna, Christian; de Lucas, Enrique Marco; Vázquez-Barquero, Alfonso; García-Porrero, Juan A; Duffau, Hugues

    2011-01-01

    Classical fiber dissection of post mortem human brains enables us to isolate a fiber tract by removing the cortex and overlying white matter. In the current work, a modification of the dissection methodology is presented that preserves the cortex and the relationships within the brain during all stages of dissection, i.e. ‘cortex-sparing fiber dissection’. Thirty post mortem human hemispheres (15 right side and 15 left side) were dissected using cortex-sparing fiber dissection. Magnetic resonance imaging study of a healthy brain was analyzed using diffusion tensor imaging (DTI)-based tractography software. DTI fiber tract reconstructions were compared with cortex-sparing fiber dissection results. The fibers of the superior longitudinal fasciculus (SLF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF) and uncinate fasciculus (UF) were isolated so as to enable identification of their cortical terminations. Two segments of the SLF were identified: first, an indirect and superficial component composed of a horizontal and vertical segment; and second, a direct and deep component or arcuate fasciculus. The IFOF runs within the insula, temporal stem and sagittal stratum, and connects the frontal operculum with the occipital, parietal and temporo-basal cortex. The UF crosses the limen insulae and connects the orbito-frontal gyri with the anterior temporal lobe. Finally, a portion of the ILF was isolated connecting the fusiform gyrus with the occipital gyri. These results indicate that cortex-sparing fiber dissection facilitates study of the 3D anatomy of human brain tracts, enabling the tracing of fibers to their terminations in the cortex. Consequently, it is an important tool for neurosurgical training and neuroanatomical research. PMID:21767263

  9. 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.

  10. The anodal tDCS over the left posterior parietal cortex enhances attention toward a focus word in a sentence.

    Science.gov (United States)

    Minamoto, Takehiro; Azuma, Miyuki; Yaoi, Ken; Ashizuka, Aoi; Mima, Tastuya; Osaka, Mariko; Fukuyama, Hidenao; Osaka, Naoyuki

    2014-01-01

    The posterior parietal cortex (PPC) has two attentional functions: top-down attentional control and stimulus-driven attentional processing. Using the focused version of the reading span test (RST), in which the target word to be remembered is the critical word for comprehending a sentence (focused word) or a non-focused word, we examined the effect of tDCS on resolution of distractor interference by the focused word in the non-focus condition (top-down attentional control) and on augmented/shrunk attentional capture by the focused word in both the focus and non-focus conditions (stimulus-driven attentional processing). Participants were divided into two groups: anodal tDCS (atDCS) and cathodal tDCS (ctDCS). Online stimulation was given while participants performed the RST. A post-hoc recognition task was also administered in which three kinds of words were presented: target words in the RST, distractor words in the RST, and novel words. atDCS augmented the effect of the focused word by increasing differences in performance between the focus and non-focus conditions. Such an effect was not observed in the ctDCS group. As for the recognition task, atDCS again produced the augmented effect of the focused words in the distractor recognition. On the other hand, ctDCS brought less recognition of non-focused target words in comparison to sham. The results indicate that atDCS promotes stimulus-driven attentional processing, possibly by affecting neural firing in the inferior parietal regions. In contrast, ctDCS appears to prevent retrieval of less important information from episodic memory, which may require top-down attentional processing.

  11. Idiopathic hypertrophic pachymeningitis presenting with occipital ...

    African Journals Online (AJOL)

    Herein, we have described, for the first time to our knowledge, a case of idiopathic pachymeningitis revealed by isolated occipital neuralgia. We found one similar case reported in the literature, but occipital neu- ralgia was not isolated as the patient also presented with tinnitus and deafness at admission. Corticosteroids did.

  12. 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

  13. 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.

  14. 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)....

  15. 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.

  16. 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.

  17. Sensitivity to syntax in visual cortex.

    Science.gov (United States)

    Dikker, Suzanne; Rabagliati, Hugh; Pylkkänen, Liina

    2009-03-01

    One of the most intriguing findings on language comprehension is that violations of syntactic predictions can affect event-related potentials as early as 120 ms, in the same time-window as early sensory processing. This effect, the so-called early left-anterior negativity (ELAN), has been argued to reflect word category access and initial syntactic structure building (Friederici, 2002). In two experiments, we used magnetoencephalography to investigate whether (a) rapid word category identification relies on overt category-marking closed-class morphemes and (b) whether violations of word category predictions affect modality-specific sensory responses. Participants read sentences containing violations of word category predictions. Unexpected items varied in whether or not their word category was marked by an overt function morpheme. In Experiment 1, the amplitude of the visual evoked M100 component was increased for unexpected items, but only when word category was overtly marked by a function morpheme. Dipole modeling localized the generator of this effect to the occipital cortex. Experiment 2 replicated the main results of Experiment 1 and eliminated two non-morphology-related explanations of the M100 contrast we observed between targets containing overt category-marking and targets that lacked such morphology. Our results show that during reading, syntactically relevant cues in the input can affect activity in occipital regions at around 125 ms, a finding that may shed new light on the remarkable rapidity of language processing.

  18. 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

  19. Imaging Characteristics of Occipital Bone Osteoblastoma

    Directory of Open Access Journals (Sweden)

    Adam Alli

    2013-01-01

    Full Text Available Osteoblastoma is a rare benign tumor of the calvarium. We present the case of a 20-year-old female with occipital osteoblastoma and discussion of imaging modalities of calvarial osteoblastoma. To our knowledge, this is the ninth reported case of occipital osteoblastoma. Imaging characterization of osteoblastoma may vary. Plain radiograph, CT, MRI, and CT angiography establish osteoblastoma characterization and vascular supply prior to surgical resection.

  20. Imaging Characteristics of Occipital Bone Osteoblastoma

    OpenAIRE

    Alli, Adam; Johnson, Philip; Reeves, Alan

    2013-01-01

    Osteoblastoma is a rare benign tumor of the calvarium. We present the case of a 20-year-old female with occipital osteoblastoma and discussion of imaging modalities of calvarial osteoblastoma. To our knowledge, this is the ninth reported case of occipital osteoblastoma. Imaging characterization of osteoblastoma may vary. Plain radiograph, CT, MRI, and CT angiography establish osteoblastoma characterization and vascular supply prior to surgical resection.

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

    Science.gov (United States)

    Franzmeier, Nicolai; Göttler, Jens; Grimmer, Timo; Drzezga, Alexander; Áraque-Caballero, Miguel A; Simon-Vermot, Lee; Taylor, Alexander N W; Bürger, Katharina; Catak, Cihan; Janowitz, Daniel; Müller, Claudia; Duering, Marco; Sorg, Christian; Ewers, Michael

    2017-01-01

    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.

  2. 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.

  3. Differential roles for parietal and occipital cortices in visual working memory.

    Directory of Open Access Journals (Sweden)

    Daisuke Matsuyoshi

    Full Text Available Visual working memory (VWM is known as a highly capacity-limited cognitive system that can hold 3-4 items. Recent studies have demonstrated that activity in the intraparietal sulcus (IPS and occipital cortices correlates with the number of representations held in VWM. However, differences among those regions are poorly understood, particularly when task-irrelevant items are to be ignored. The present fMRI-based study investigated whether memory load-sensitive regions such as the IPS and occipital cortices respond differently to task-relevant information. Using a change detection task in which participants are required to remember pre-specified targets, here we show that while the IPS exhibited comparable responses to both targets and distractors, the dorsal occipital cortex manifested significantly weaker responses to an array containing distractors than to an array containing only targets, despite that the number of objects presented was the same for the two arrays. These results suggest that parietal and occipital cortices engage differently in distractor processing and that the dorsal occipital, rather than parietal, activity appears to reflect output of stimulus filtering and selection based on behavioral relevance.

  4. Feasibility of Ultrasound Guided Atlanto-occipital Joint Injection

    OpenAIRE

    Won, Sun Jae; Lee, U-Young; Cho, Sei Un; Rhee, Won Ihl

    2012-01-01

    Objective To evaluate the feasibility of ultrasound guided atlanto-occipital joint injection. Method Six atlanto-occipital joints of three cadavers were examined. Cadavers were placed in prone position with their head slightly rotated towards the contra-lateral side. The atlanto-occipital joint was initially identified with a longitudinal ultrasound scan at the midline between occipital protuberance and mastoid process. Contrast media 0.5cc was injected into the atlanto-occipital joint using ...

  5. 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.

  6. 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].

  7. Atlanto-occipital fusion: A case report

    Directory of Open Access Journals (Sweden)

    Monalisa

    2015-01-01

    Full Text Available The atlas is the first cervical vertebra. In the history of anatomy, due to its primary function of supporting the skull, it has been innumerably compared with Atlas the Greek God, who holds the globe of the earth on his shoulders. This vertebra is devoid of a body and has two prominent lateral masses bearing a pair of superior concave facets and inferior smooth facets each. Atlanto-occipital fusion may be unilateral or bilateral, complete or incomplete and symptomatic or asymptomatic. In our, case atlanto-occipital fusion was observed in the skull of a male cadaver. Our study will be of significance to clinicians in the specialties of radiodiagnosis, orthopedics, neurosurgery and anesthesiology. Because of a lack of knowledge of developmental malformation in the craniocervical region, sudden death can occur during clinical manipulation. Head and neck surgeons must keep in mind that such anomaly can exist without any prior symptoms. The specimen seen represents a case of congenital fusion. The articular processes of the specimen are fused between the occipital and the atlas bones. Atlanto-occipital fusion decreases the diameter of the foramen magnum and produce neurovascular symptoms.

  8. 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.

  9. 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.

  10. Occipital Sinus Thrombosis: An Exceptional Case Report.

    Science.gov (United States)

    Beyrouti, Rahma; Mansour, Malek; Kacem, Amel; Zaouali, Jamel; Mrissa, Ridha

    2016-06-01

    Variations of the dural venous sinuses may result in inaccurate imaging interpretation or complications during surgical approaches. One variation of the dural venous sinuses reported infrequently in the literature is the occipital sinus. We report an exceptional case of occipital sinus thrombosis. A 48-year-old right-handed man with a 5-month history of hypertension and chronic renal failure presented with cephalalgia, vomiting, and blurred vision evolving over 48 hours. Neurological examination revealed papillary edema stage 1 with no others abnormalities. An initial brain computed tomography (CT) scan performed was normal. The opening pressure of cerebrospinal fluid (CSF) was 35 cmH2O with normal level of protein and no hypercellularity in CSF analysis. The evolution was marked by the occurrence of generalized tonic-clonic seizure. A second CT scan performed showed a hyperdensity of the occipital sinus. Magnetic resonance imaging and magnetic resonance venography studies confirmed the diagnosis with highlighting the thrombosis of the occipital sinus in association to an ectasia of the torcular. The patient received adequate anticoagulation for 6 months in association to antiepileptic drugs with a good evolution. According to our review, such a thrombosis must be a rare condition, because our literature search has shown a lack of any report describing this condition. Herein, we review the anatomy of the occipital sinus and we illustrate the characteristics of this unusual thrombosis with multiple imaging modalities. Understanding of the cerebral venous anatomy and recognition of venous variations essentially help when dealing with a pathology, which presents along with a particular venous variation, no matter how rare this combination is. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. 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.

  12. 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.

  13. Left dorsal speech stream components and their contribution to phonological processing.

    Science.gov (United States)

    Murakami, Takenobu; Kell, Christian A; Restle, Julia; Ugawa, Yoshikazu; Ziemann, Ulf

    2015-01-28

    Models propose an auditory-motor mapping via a left-hemispheric dorsal speech-processing stream, yet its detailed contributions to speech perception and production are unclear. Using fMRI-navigated repetitive transcranial magnetic stimulation (rTMS), we virtually lesioned left dorsal stream components in healthy human subjects and probed the consequences on speech-related facilitation of articulatory motor cortex (M1) excitability, as indexed by increases in motor-evoked potential (MEP) amplitude of a lip muscle, and on speech processing performance in phonological tests. Speech-related MEP facilitation was disrupted by rTMS of the posterior superior temporal sulcus (pSTS), the sylvian parieto-temporal region (SPT), and by double-knock-out but not individual lesioning of pars opercularis of the inferior frontal gyrus (pIFG) and the dorsal premotor cortex (dPMC), and not by rTMS of the ventral speech-processing stream or an occipital control site. RTMS of the dorsal stream but not of the ventral stream or the occipital control site caused deficits specifically in the processing of fast transients of the acoustic speech signal. Performance of syllable and pseudoword repetition correlated with speech-related MEP facilitation, and this relation was abolished with rTMS of pSTS, SPT, and pIFG. Findings provide direct evidence that auditory-motor mapping in the left dorsal stream causes reliable and specific speech-related MEP facilitation in left articulatory M1. The left dorsal stream targets the articulatory M1 through pSTS and SPT constituting essential posterior input regions and parallel via frontal pathways through pIFG and dPMC. Finally, engagement of the left dorsal stream is necessary for processing of fast transients in the auditory signal. Copyright © 2015 the authors 0270-6474/15/351411-12$15.00/0.

  14. 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.

  15. A gliotoxin model of occipital seizures in rats.

    Science.gov (United States)

    Mirsattari, Seyed M; Shen, Bixia; Leung, L Stan; Rajakumar, Nagalingam

    2008-09-01

    Intracortical microinjection of fluorocitrate, a reversible inhibitor of glial tricarboxylic acid (TCA), results in impaired glial metabolism and epileptic seizures. To determine the potential contribution of epileptic activities to the metabolic properties of fluorocitrate, we investigated the seizure-inducing property of fluorocitrate at different doses. Twenty-seven male Sprague Dawley rats (250-400g) were studied with chronically implanted electrodes and cannulae in the occipital cortices. A week after surgery, awake behaving rats were injected with 0.2microl solution containing various concentrations of fluorocitrate or saline in the right occipital cortex; two sham-treated animals did not receive an injection. EEG was recorded with implanted electrodes. Thionin staining was used to verify injection sites. Twenty rats underwent immunohistochemistry for glial fibrilary acidic protein (GFAP) and neuronal nuclear-specific antigen (NeuN) 48h after the injections. Seizures developed within an hour of injection in all the rats that received > or =0.8nmol fluorocitrate and 2 of 4 rats that received 0.4nmol fluorocitrate. Five of 12 animals that received > or =1.2nmol fluorocitrate experienced status epilepticus. There was a significant increase in GFAP staining at the injection site in doses > or =0.8nmol fluorocitrate. There was only mild neuronal loss revealed by NeuN staining at the injection site in the animals that had received 1.6nmol flourocitrate. This study shows that fluorocitrate results in focal epileptic seizures with secondary generalization in a dose-dependent manner, including low doses of this agent previously used for studies of brain metabolism.

  16. Decreased neural activity and neural connectivity while performing a set-shifting task after inhibiting repetitive transcranial magnetic stimulation on the left dorsal prefrontal cortex

    NARCIS (Netherlands)

    Gerrits, N.J.H.M.; van den Heuvel, O.A.; van der Werf, Y.D.

    2015-01-01

    Background: Sub-optimal functioning of the dorsal prefrontal cortex (PFC) is associated with executive dysfunction, such as set-shifting deficits, in neurological and psychiatric disorders. We tested this hypothesis by investigating the effect of low-frequency 'inhibiting' off-line repetitive

  17. Decreased neural activity and neural connectivity while performing a set-shifting task after inhibiting repetitive transcranial magnetic stimulation on the left dorsal prefrontal cortex

    NARCIS (Netherlands)

    Gerrits, Niels J H M; van den Heuvel, Odile A; van der Werf, Ysbrand D

    2015-01-01

    BACKGROUND: Sub-optimal functioning of the dorsal prefrontal cortex (PFC) is associated with executive dysfunction, such as set-shifting deficits, in neurological and psychiatric disorders. We tested this hypothesis by investigating the effect of low-frequency 'inhibiting' off-line repetitive

  18. Prefrontal and occipital asymmetry and volume in boys with autism spectrum disorder.

    Science.gov (United States)

    Knaus, Tracey A; Tager-Flusberg, Helen; Mock, Jeffrey; Dauterive, Rachel; Foundas, Anne L

    2012-12-01

    To examine prefrontal and occipital asymmetry (brain torque) in boys with autism spectrum disorder (ASD) and controls. A secondary aim was to study age-related changes in gray and white matter volume. Several studies have found atypical early cortical development in ASD. Atypical brain torque, defined as a greater-than-normal left prefrontal and right occipital asymmetry, has been found in some studies of children and adults with ASD. This configuration may be an early neural marker of ASD risk. We studied 24 right-handed boys with ASD and 27 typically developing right-handed boys, 7 to 15 years old, obtaining neuropsychological profiles and measuring prefrontal and occipital volumes on magnetic resonance images. Most participants had the expected rightward prefrontal and leftward occipital asymmetry, with no group differences in direction or degree of asymmetry. We found a trend toward larger prefrontal volume in the ASD group than in the controls. The controls also had a trend toward differences in age associations, correlating with total and left prefrontal white matter volumes. Our findings suggest that atypical brain torque may not be a neural signature of ASD, although our sample was limited to high-functioning, right-handed boys. Our results provide support for aberrant cortical development in ASD, continuing into adolescence, with prefrontal regions being disproportionally affected.

  19. 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 ...

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

    African Journals Online (AJOL)

    Nancy Mohamed El Sekily

    2014-08-19

    Aug 19, 2014 ... After 1 month, 60% of patients still showed improvement. Conclusion: 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 eliminating chronic migraine headache.

  1. Occipital Nerve Field Transcranial Direct Current Stimulation Normalizes Imbalance Between Pain Detecting and Pain Inhibitory Pathways in Fibromyalgia.

    Science.gov (United States)

    De Ridder, Dirk; Vanneste, Sven

    2017-04-01

    Occipital nerve field (OCF) stimulation with subcutaneously implanted electrodes is used to treat headaches, more generalized pain, and even failed back surgery syndrome via unknown mechanisms. Transcranial direct current stimulation (tDCS) can predict the efficacy of implanted electrodes. The purpose of this study is to unravel the neural mechanisms involved in global pain suppression, mediated by occipital nerve field stimulation, within the realm of fibromyalgia. Nineteen patients with fibromyalgia underwent a placebo-controlled OCF tDCS. Electroencephalograms were recorded at baseline after active and sham stimulation. In comparison with healthy controls, patients with fibromyalgia demonstrate increased dorsal anterior cingulate cortex, increased premotor/dorsolateral prefrontal cortex activity, and an imbalance between pain-detecting dorsal anterior cingulate cortex and pain-suppressing pregenual anterior cingulate cortex activity, which is normalized after active tDCS but not sham stimulation associated with increased pregenual anterior cingulate cortex activation. The imbalance improvement between the pregenual anterior cingulate cortex and the dorsal anterior cingulate cortex is related to clinical changes. An imbalance assumes these areas communicate and, indeed, abnormal functional connectivity between the dorsal anterior cingulate cortex and pregenual anterior cingulate cortex is noted to be caused by a dysfunctional effective connectivity from the pregenual anterior cingulate cortex to the dorsal anterior cingulate cortex, which improves and normalizes after real tDCS but not sham tDCS. In conclusion, OCF tDCS exerts its effect via activation of the descending pain inhibitory pathway and de-activation of the salience network, both of which are abnormal in fibromyalgia.

  2. The Sunrise Technique: the correction of occipital plagiocephaly using bandeau occipital plate and radial osteotomies.

    Science.gov (United States)

    Jimenez, D F; Barone, C M

    1995-01-01

    Posterior plagiocephaly secondary to lambdoid suture stenosis requires surgical release and repair to prevent progressive deformational changes associated with a suture stenosis. A surgical technique is described for release of the stenosed lambdoid suture and asterion region, followed by occipital reconstruction. This technique provides excellent cosmetic results. Using a standard biparietal incision, most of the occipital bone is removed en bloc. The asymmetric occiput is then reconstructed using an autologous bone bandeau and Marchac forehead template graft. The remaining bone is cut into longitudinal strips and placed in a centrifugal fashion around this construct. This technique creates a stable unit that provides immediate symmetry to the occipital area. The operative time and blood loss are comparable to that of similar procedures. With this technique there have been no complications or need for reoperation.

  3. Glutamate is down-regulated and tinnitus loudness-levels decreased following rTMS over auditory cortex of the left hemisphere: A prospective randomized single-blinded sham-controlled cross-over study.

    Science.gov (United States)

    Cacace, Anthony T; Hu, Jiani; Romero, Stephen; Xuan, Yang; Burkard, Robert F; Tyler, Richard S

    2017-11-14

    Using a prospective randomized single-blinded sham-controlled cross-over design, we studied the efficacy of low frequency (1-Hz) repetitive transcranial magnetic stimulation (rTMS) over auditory cortex of the left temporal lobe as an experimental treatment modality for noise-induced tinnitus. Pre/post outcome measures for sham vs. active rTMS conditions included differential changes in tinnitus loudness, self-perceived changes in the Tinnitus Handicap Questionnaire (THQ), and neurochemical changes of brain metabolite concentrations using single voxel proton magnetic resonance spectroscopy ( 1 H-MRS) obtained from left and right auditory cortical areas. While no subject in our sample had complete abatement of their tinnitus percept, active but not sham rTMS significantly reduced the loudness level of the tinnitus perception on the order of 4.5 dB; improved subscales in several content areas on the THQ, and down regulated (reduced) glutamate concentrations specific to the auditory cortex of the left temporal lobe that was stimulated. In addition, significant pair-wise correlations were observed among questionnaire variables, metabolite variables, questionnaire-metabolite variables, and metabolite-loudness variables. As part of this correlation analysis, we demonstrate for the first time that active rTMS produced a down regulation in the excitatory neurotransmitter glutamate that was highly correlated (r = 0.77, p < 0.05) with a reduction in tinnitus loudness levels measured psychoacoustically with a magnitude estimation procedure. Overall, this study provides unique information on neurochemical, psychoacoustic, and questionnaire-related profiles which emphasizes the emerging fields of perceptual and cognitive MRS and provides a perspective on a new frontier in auditory and tinnitus-related research. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. OCCIPITAL WAR TRAUMA AND VISUAL FIELD DEFECTS

    Directory of Open Access Journals (Sweden)

    ZAHRA AALAMI-HARANDI

    1986-05-01

    Full Text Available Seven cases of visual field defects, caused by wartrauma were seen at Farabi Eye Hospital. None were referred by a neurologist. Four patients had 20/20 visions with normal fundi. One had 12/20, in both eyes, with normal fundi. Two patients presented fundus changes."nThe visual field defects were seen in all these seven patients. Four had homonymous hemianopia, one had bilateral field restriction, one patient had homonymous quadrianopia, one had unilateral restriction of the visual field, and the last one had bilateral loss of the inferior fields. The Cat-scan of six patients indicated the lesion of occiput and occipital lobe. One patient had a diffuse cerebral lesion.

  10. Greater occipital nerve blockade in cervicogenic headache

    Directory of Open Access Journals (Sweden)

    VINCENT MAURICE B.

    1998-01-01

    Full Text Available Cervicocogenic headache (CeH is a relatively common disorder. Although no ideal treatment is available so far, blockades in different structures and nerves may be temporarily effective. We studied the effects of 1-2 mL 0.5% bupivacaine injection at the ipsilateral greater occipital nerve (GON in 41 CeH patients. The pain is significantly reduced both immediately and as long as 7 days after the blockade. The improvement is less marked during the first two days, a phenomenon we called "tilde pattern". GON blockades may reduce the pool of exaggerated sensory input and antagonize a putative "wind-up-like effect" which may explain the headache improvement.

  11. Occipital Artery Pseudoaneurysm After Posterior Fossa Craniotomy.

    Science.gov (United States)

    Srinivasan, Visish M; Karas, Patrick J; Sen, Anish N; Fridley, Jared S; Chen, Stephen R; Gopinath, Shankar P

    2017-02-01

    Pseudoaneurysms of scalp arteries have been reported in rare cases after iatrogenic injury; however, they are far more commonly seen after traumatic injuries. They are usually associated with the superficial temporal artery; however, there have been a few reports of psuedoaneurysms of the occipital artery (OA). We present a unique case of an OA pseudoaneurysm presenting with delayed postoperative hemorrhage after a retrosigmoid craniotomy. The pseudoaneurysm was treated by coil embolization. The patient recovered fully after endovascular embolization. Other treatment options for pseudoaneurysms of facial, temporal, and scalp arteries include surgical clipping/trapping with excision, Hunterian ligation, or direct compression. Pseudoaneurysms of extracranial scalp arteries are rare and most often caused by traumatic compression of the artery against a bony ridge. Despite their rarity, pseudoaneurysms secondary to iatrogenic injury to extracranial arteries should be considered in the differential diagnosis in patients presenting with delayed incisional pain, redness, and swelling. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Remnants of occipital vertebrae: proatlas segmentation abnormalities.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 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

  15. Occipital Neuralgia With Atypic Symptoms: A Case Report

    Directory of Open Access Journals (Sweden)

    Gökçen Gözübatık-çelik

    2014-12-01

    Full Text Available Cranial neuralgia is a rare form of headache disorders characterized with transient and unilateral attacks. Inflamatuar diseases and cervical compression are amongst the most common etiological factors even so idiopathic forms might be observed. International Classification of Headache Disorders (ICHD-2made the classification of cranial neuralgias in 18 different groups. Occipital neuralgia, being a subgroup of cranial neuralgies, is a headache that involves anatomically at major, minor or third occipital nerve areas sometimes accompanying with sensory deficits or dysesthesia. Occipital neuralgia includes aching burning or throbbing headache that is often unilateral and continuous with intermittent shocking and shooting pain on the occipital nerve area. Patients with occipital neuralgia can be divided into those with structural causes and those with idiopathic causes. Structural lesions are cervical disc diseases, trauma, compression of the cervical discs. Tumors rarely metastasize to the paravertebral region and compression of the cervical nerve roots may result in occipital neuralgia. Our aim is to present a case with late onset medical refractory occipital neuralgia due to metastatic prostate cancer, emphasizing that relevant medical history should alert clinicans to the possibility of metastasis causing occipital neuralgia.

  16. 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.

  17. 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.

  18. 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)

  19. Task constraints modulate activation in right ventral lateral prefrontal cortex.

    Science.gov (United States)

    Vartanian, Oshin; Goel, Vinod

    2005-10-01

    Lesion data suggest that right prefrontal cortex (PFC) plays a critical role in open-ended problem solving. To test this hypothesis, we scanned fifteen normal subjects with fMRI as they completed three types of anagram problems varying in the level of constraints placed on the search space. On unconstrained trials, they rearranged letters to generate solutions (e.g., Can you make a "Word with ZJAZ?"). On semantically constrained trials, they rearranged letters to generate solutions within particular semantic categories (e.g., Can you make a type of "Music with ZJAZ?"). On baseline trials, they rearranged letters to make specific words (e.g., Can you make the word "JAZZ with ZJAZ?"). As predicted, the critical comparison of unconstrained vs. semantically constrained trials revealed significant activation in right ventral lateral PFC, as well as left superior frontal gyrus, frontopolar cortex, right superior parietal lobe, right post central gyrus, and the occipital-parietal sulcus. Furthermore, activation in right ventral lateral PFC (BA 47) increased as the constraints placed on the anagram search space were reduced. We argue that the activation in right ventral lateral PFC is related to hypothesis generation in unconstrained settings, whereas activation in other structures is related to additional processes linked to anagram problems such as semantic retrieval, semantic categorization, and cognitive monitoring. These results extend the lesion data and imaging studies by demonstrating that a relative absence of constraints on the solution space is sufficient to engage right ventral lateral PFC in hypothesis generation tasks.

  20. 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.

  1. 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

  2. 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

  3. Effects of chronic exposure to 950 MHz ultra-high-frequency electromagnetic radiation on reactive oxygen species metabolism in the right and left cerebral cortex of young rats of different ages.

    Science.gov (United States)

    Furtado-Filho, Orlando V; Borba, Juliana B; Maraschin, Tatiana; Souza, Larissa M; Henriques, João A P; Moreira, José C F; Saffi, Jenifer

    2015-01-01

    To assess the effect of 950 MHz ultra-high-frequency electromagnetic radiation (UHF-EMR) on biomarkers of oxidative damage to DNA, proteins and lipids in the left cerebral cortex (LCC) and right cerebral cortex (RCC) of neonate and 6-day-old rats. Twelve rats were equally divided into two groups as controls (CR) and exposed (ER), for each age (0 and 6 days). The LCC and RCC were examined in ER and CR after exposure. Radiation exposure lasted 30 min per day for up to 27 days (throughout pregnancy and 6 days postnatal). The specific absorption rate ranged from 1.32-1.14 W/kg. The damage to lipids, proteins and DNA was verified by thiobarbituric acid reactive substances, carbonylated proteins (CP) and comets, respectively. The concentration of glucose in the peripheral blood of the rats was measured by the Accu-Chek Active Kit due to increased CP in RCC. In neonates, no modification of the biomarkers tested was detected. On the other hand, there was an increase in the levels of CP in the RCC of the 6-day-old ER. Interestingly, the concentration of blood glucose was decreased in this group. Our results indicate that there is no genotoxicity and oxidative stress in neonates and 6 days rats. However, the RCC had the highest concentration of CP that do not seem to be a consequence of oxidative stress. This study is the first to demonstrate the use of UHF-EMR causes different damage responses to proteins in the LCC and RCC.

  4. A Case of Occipital Neuralgia in the Greater and Lesser Occipital Nerves Treated with Neurectomy by Using Transcranial Doppler Sonography: Technical Aspects

    OpenAIRE

    Jung, Sang Jin; Moon, Seong Keun; Kim, Tae Young; Eom, Ki Seong

    2011-01-01

    Occipital neuralgia is usually defined as paroxysmal stabbing pain in the greater or lesser occipital nerve (GON or LON) distribution. In occipital neuralgia patients, surgical considerations are carefully taken into account if medical management is ineffective. However, identification of the occipital artery by palpation in patients with thick necks or small occipital arteries can be technically difficult. Therefore, we established a new technique using transcranial Doppler (TCD) sonography ...

  5. Traumatic atlanto-occipital dislocation: a case report

    OpenAIRE

    DEFINO, Helton; PORTO, Maximiliano Aguiar; HERRERO, Carlos Fernando Pereira da Silva; ROMEIRO, Carlos Frederico Wanderley Estelita; BARBOSA, Marcello Henrique Nogueira

    2008-01-01

    A luxação traumática atlanto-occipital é lesão rara, de incidência desconhecida e está associada a elevada taxa de mortalidade. Os autores relatam o diagnóstico, tratamento e seguimento de dois anos de uma paciente de 25 anos de idade, vítima de acidente automobilístico e luxação atlanto-occipital traumática confirmada por exames de imagem.Traumatic atlanto-occipital dislocation is a rare lesion whose incidence is not know, and which is associated to a high rate of mortality. The authors repo...

  6. 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.

  7. 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.

  8. T'ain't what you say, it's the way that you say it--left insula and inferior frontal cortex work in interaction with superior temporal regions to control the performance of vocal impersonations.

    Science.gov (United States)

    McGettigan, Carolyn; Eisner, Frank; Agnew, Zarinah K; Manly, Tom; Wisbey, Duncan; Scott, Sophie K

    2013-11-01

    Historically, the study of human identity perception has focused on faces, but the voice is also central to our expressions and experiences of identity [Belin, P., Fecteau, S., & Bedard, C. Thinking the voice: Neural correlates of voice perception. Trends in Cognitive Sciences, 8, 129-135, 2004]. Our voices are highly flexible and dynamic; talkers speak differently, depending on their health, emotional state, and the social setting, as well as extrinsic factors such as background noise. However, to date, there have been no studies of the neural correlates of identity modulation in speech production. In the current fMRI experiment, we measured the neural activity supporting controlled voice change in adult participants performing spoken impressions. We reveal that deliberate modulation of vocal identity recruits the left anterior insula and inferior frontal gyrus, supporting the planning of novel articulations. Bilateral sites in posterior superior temporal/inferior parietal cortex and a region in right middle/anterior STS showed greater responses during the emulation of specific vocal identities than for impressions of generic accents. Using functional connectivity analyses, we describe roles for these three sites in their interactions with the brain regions supporting speech planning and production. Our findings mark a significant step toward understanding the neural control of vocal identity, with wider implications for the cognitive control of voluntary motor acts.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Analysis of haptic information in the cerebral cortex

    Science.gov (United States)

    2016-01-01

    Haptic sensing of objects acquires information about a number of properties. This review summarizes current understanding about how these properties are processed in the cerebral cortex of macaques and humans. Nonnoxious somatosensory inputs, after initial processing in primary somatosensory cortex, are partially segregated into different pathways. A ventrally directed pathway carries information about surface texture into parietal opercular cortex and thence to medial occipital cortex. A dorsally directed pathway transmits information regarding the location of features on objects to the intraparietal sulcus and frontal eye fields. Shape processing occurs mainly in the intraparietal sulcus and lateral occipital complex, while orientation processing is distributed across primary somatosensory cortex, the parietal operculum, the anterior intraparietal sulcus, and a parieto-occipital region. For each of these properties, the respective areas outside primary somatosensory cortex also process corresponding visual information and are thus multisensory. Consistent with the distributed neural processing of haptic object properties, tactile spatial acuity depends on interaction between bottom-up tactile inputs and top-down attentional signals in a distributed neural network. Future work should clarify the roles of the various brain regions and how they interact at the network level. PMID:27440247

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

    Directory of Open Access Journals (Sweden)

    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

  15. 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

  16. Selective involvement of superior frontal cortex during working memory for shapes.

    Science.gov (United States)

    Yee, Lydia T S; Roe, Katherine; Courtney, Susan M

    2010-01-01

    A spatial/nonspatial functional dissociation between the dorsal and ventral visual pathways is well established and has formed the basis of domain-specific theories of prefrontal cortex (PFC). Inconsistencies in the literature regarding prefrontal organization, however, have led to questions regarding whether the nature of the dissociations observed in PFC during working memory are equivalent to those observed in the visual pathways for perception. In particular, the dissociation between dorsal and ventral PFC during working memory for locations versus object identities has been clearly present in some studies but not in others, seemingly in part due to the type of objects used. The current study compared functional MRI activation during delayed-recognition tasks for shape or color, two object features considered to be processed by the ventral pathway for perceptual recognition. Activation for the shape-delayed recognition task was greater than that for the color task in the lateral occipital cortex, in agreement with studies of visual perception. Greater memory-delay activity was also observed, however, in the parietal and superior frontal cortices for the shape than for the color task. Activity in superior frontal cortex was associated with better performance on the shape task. Conversely, greater delay activity for color than for shape was observed in the left anterior insula and this activity was associated with better performance on the color task. These results suggest that superior frontal cortex contributes to performance on tasks requiring working memory for object identities, but it represents different information about those objects than does the ventral frontal cortex.

  17. 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

  18. 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.)

  19. 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.

  20. Innervation of sonic muscles in teleosts: occipital vs. spinal nerves.

    Science.gov (United States)

    Onuki, Atsushi; Somiya, Hiroaki

    2007-01-01

    The innervation of sonic muscles in teleosts has been categorized into three types: occipital nerve, spinal nerve, and a combination of occipital and spinal nerves. The innervation patterns of sonic muscles were examined (or re-examined) in seven sonic fish species (rockfish, pinecone fish, sweeper, tigerfish, piranha, dory, and pollack) that use the sonic muscles to vibrate the swimbladder. The peripheral nerves (occipital or spinal) were identified based on skeletal preparations. The sonic muscle innervation was of the occipital type in four species (rockfish, pinecone fish, sweeper, and tigerfish) and of the spinal type in three species (piranha, dory, and pollack); none of the seven species examined showed the combination type. Therefore, we hypothesized that innervation patterns could be divided simply into occipital and spinal types. Moreover, the present results revealed that previously reported innervation patterns are inaccurate for three species (tigerfish, piranha, and dory) re-examined in this study. Therefore, it is important to define the peripheral nerves precisely, by using skeletal preparations, in future investigations of sonic muscle innervation. Copyright 2007 S. Karger AG, Basel.

  1. TMS to the "occipital face area" affects recognition but not categorization of faces.

    Science.gov (United States)

    Solomon-Harris, Lily M; Mullin, Caitlin R; Steeves, Jennifer K E

    2013-12-01

    The human cortical system for face perception is comprised of a network of connected regions including the middle fusiform gyrus ("fusiform face area" or FFA), the inferior occipital cortex ("occipital face area" or OFA), and the superior temporal sulcus. The traditional hierarchical feedforward model of visual processing suggests information flows from early visual cortex to the OFA for initial face feature analysis to higher order regions including the FFA for identity recognition. However, patient data suggest an alternative model. Patients with acquired prosopagnosia, an inability to visually recognize faces, have been documented with lesions to the OFA but who nevertheless show face-selective activation in the FFA. Moreover, their ability to categorize faces remains intact. This suggests that the FFA is not solely responsible for face recognition and the network is not strictly hierarchical, but may be organized in a reverse hierarchical fashion. We used transcranial magnetic stimulation (TMS) to temporarily disrupt processing in the OFA in neurologically-intact individuals and found participants' ability to categorize intact versus scrambled faces was unaffected, however face identity discrimination was significantly impaired. This suggests that face categorization but not recognition can occur without the "earlier" OFA being online and indicates that "lower level" face category processing may be assumed by other intact face network regions such as the FFA. These results are consistent with the patient data and support a non-hierarchical, global-to-local model with re-entrant connections between the OFA and other face processing areas. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Occipital Nerve Blocks for Pediatric Posttraumatic Headache: A Case Series.

    Science.gov (United States)

    Seeger, Trevor A; Orr, Serena; Bodell, Lisa; Lockyer, Lisette; Rajapakse, Thilinie; Barlow, Karen M

    2015-08-01

    Posttraumatic headache is one of the most common and disabling symptoms after traumatic brain injury. However, evidence for treating posttraumatic headache is sparse, especially in the pediatric literature. This retrospective chart review evaluated the use of occipital nerve blocks in adolescents treated for posttraumatic headache following mild traumatic brain injury, presenting to the Complex Concussion and Traumatic Brain Injury clinic. Fifteen patients (mean age 15.47; range: 13-17) received occipital nerve block for posttraumatic headache. Follow-up was obtained in 14 patients at 5.57 (standard deviation = 3.52) months postinjury. The headache burden was high, with all except one having headaches 15 or more days per month (median 30, range 10-30). Sixty-four percent reported long-term response to the occipital nerve blocks, with associated improved quality of life and decreased postconcussion symptom scores (P headache. © The Author(s) 2014.

  3. EEG Correlates of Preparatory Orienting, Contextual Updating, and Inhibition of Sensory Processing in Left Spatial Neglect.

    Science.gov (United States)

    Lasaponara, Stefano; D'Onofrio, Marianna; Pinto, Mario; Dragone, Alessio; Menicagli, Dario; Bueti, Domenica; De Lucia, Marzia; Tomaiuolo, Francesco; Doricchi, Fabrizio

    2018-04-11

    Studies with event-related potentials have highlighted deficits in the early phases of orienting to left visual targets in right-brain-damaged patients with left spatial neglect (N+). However, brain responses associated with preparatory orienting of attention, with target novelty and with the detection of a match/mismatch between expected and actual targets (contextual updating), have not been explored in N+. Here in a study in healthy humans and brain-damaged patients of both sexes we demonstrate that frontal activity that reflects supramodal mechanisms of attentional orienting (Anterior Directing Attention Negativity, ADAN) is entirely spared in N+. In contrast, posterior responses that mark the early phases of cued orienting (Early Directing Attention Negativity, EDAN) and the setting up of sensory facilitation over the visual cortex (Late Directing Attention Positivity, LDAP) are suppressed in N+. This uncoupling is associated with damage of parietal-frontal white matter. N+ also exhibit exaggerated novelty reaction to targets in the right side of space and reduced novelty reaction for those in the left side (P3a) together with impaired contextual updating (P3b) in the left space. Finally, we highlight a drop in the amplitude and latency of the P1 that over the left hemisphere signals the early blocking of sensory processing in the right space when targets occur in the left one: this identifies a new electrophysiological marker of the rightward attentional bias in N+. The heterogeneous effects and spatial biases produced by localized brain damage on the different phases of attentional processing indicate relevant functional independence among their underlying neural mechanisms and improve the understanding of the spatial neglect syndrome. SIGNIFICANCE STATEMENT Our investigation answers important questions: are the different components of preparatory orienting (EDAN, ADAN, LDAP) functionally independent in the healthy brain? Is preparatory orienting of

  4. Non-traumatic posterior atlanto-occipital joint dislocation

    OpenAIRE

    Takechi, Yasuhiko; Iizuka, Haku; Sorimachi, Yasunori; Ara, Tsuyoshi; Nishinome, Masahiro; Takagishi, Kenji

    2010-01-01

    This report presents a case of non-traumatic posterior atlanto-occipital dislocation. A 36-year-old female was referred with a history of numbness of the extremities, vertigo and neck pain for 1 year. The patient had no history of trauma. The axial rotation of range of motion of the cervical spine was severely restricted. A lateral cervical radiograph in the neutral position demonstrated a posterior atlanto-occipital dislocation. A coronal view on a computed tomography (CT) reconstruction ima...

  5. 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…

  6. 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

  7. 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...

  8. 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.

  9. Late-onset childhood occipital epilepsy. An unusual case in adolescence and differential diagnosis with migraine

    OpenAIRE

    Liberalesso, Paulo Breno Noronha; Silva, Izabella Celidônio Bertoldo da; Klagenberg, Karlin Fabianne; Jurkiewicz, Ari Leon; Zeigelboim, Bianca Simone

    2009-01-01

    INTRODUCTION: The new proposed classification of ILAE Task Force (2001) proposes that the occipital epilepsies should be split into two subtypes: an early-onset benign childhood occipital epilepsy (or Panayiotopoulos type) and late-onset childhood occipital epilepsy (or Gastaut type). Migraine with visual aura must be considered as a differential diagnosis in childhood and adolescents with occipital epilepsy without motor phenomena. OBJECTIVE: The goal of our paper is to report the case a 16-...

  10. 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.

  11. 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.)

  12. 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

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  1. 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

  2. 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.

  3. 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

    2015-02-01

    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). 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. 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). 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. © 2014 Wiley Periodicals, Inc.

  4. FEATURES OF NEUROENERGYMETABOLISM AND ACTIVATION INFLUENCES ON CEREBRAL CORTEX IN CHILDREN OF PRIMARY SHOOL AGE WITH DIFFERENT TYPES OF TEMPERAMENT AND SUCCESS IN LEARNING

    Directory of Open Access Journals (Sweden)

    Natalya Sergeevna Bedereva

    2017-01-01

    Full Text Available The aim of the study was to identify the relationship with intensity of energy metabolism and the level of activation of the cerebral cortex in primary schoolchildren with different temperament characteristic and their possible influence on successful learning. The study involved 148 children of primary school age. Determination of the level energetic metabolism and activation influences on the cerebral cortex was carried out by using methods of neuroenergymapping and omega-metry. The study of temperament types was performed by using a questionnaire proposed by A. Thomas and adapted for use in conditions of our country. Revealed differences in operation of the modulating system in schoolchildren with different temperamental signs. Children with the type of «Adequate» were characterized by an optimal level of activation and the intensity of energetic metabolism of the cerebral cortex. “Intense” had high level of activation and expressive level of neuroenergymetabolism, “Quiet” showed reduced the intensity of energy metabolism of the cerebral cortex. Some features of cerebral cortex activity, influencing the functional state (FS during the study, were revealed. In children with low success of learning symmetrical activation of the hemispheres and the redistribution of DCP level with the highest values in the occipital region and a parallel decrease in the Central parts of the cerebral cortex, were determined. More successful children had a significant asymmetry of activity cerebral hemispheres due to the dominance of the left, which led to generation of an adequate functional state during the study, which favoring more productivity learning activities. Thus, state of activating mechanisms neurometabolic reactions of the brain and temperamental characteristics are important factors, influencing success of primary schoolchildren’s learning.

  5. "Visual" Cortex Responds to Spoken Language in Blind Children.

    Science.gov (United States)

    Bedny, Marina; Richardson, Hilary; Saxe, Rebecca

    2015-08-19

    Plasticity in the visual cortex of blind individuals provides a rare window into the mechanisms of cortical specialization. In the absence of visual input, occipital ("visual") brain regions respond to sound and spoken language. Here, we examined the time course and developmental mechanism of this plasticity in blind children. Nineteen blind and 40 sighted children and adolescents (4-17 years old) listened to stories and two auditory control conditions (unfamiliar foreign speech, and music). We find that "visual" cortices of young blind (but not sighted) children respond to sound. Responses to nonlanguage sounds increased between the ages of 4 and 17. By contrast, occipital responses to spoken language were maximal by age 4 and were not related to Braille learning. These findings suggest that occipital plasticity for spoken language is independent of plasticity for Braille and for sound. We conclude that in the absence of visual input, spoken language colonizes the visual system during brain development. Our findings suggest that early in life, human cortex has a remarkably broad computational capacity. The same cortical tissue can take on visual perception and language functions. Studies of plasticity provide key insights into how experience shapes the human brain. The "visual" cortex of adults who are blind from birth responds to touch, sound, and spoken language. To date, all existing studies have been conducted with adults, so little is known about the developmental trajectory of plasticity. We used fMRI to study the emergence of "visual" cortex responses to sound and spoken language in blind children and adolescents. We find that "visual" cortex responses to sound increase between 4 and 17 years of age. By contrast, responses to spoken language are present by 4 years of age and are not related to Braille-learning. These findings suggest that, early in development, human cortex can take on a strikingly wide range of functions. Copyright © 2015 the authors 0270-6474/15/3511674-08$15.00/0.

  6. 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.

  7. 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.

  8. Occipital Neuralgia after Hair Transplantation and Its Treatment

    Directory of Open Access Journals (Sweden)

    Jason Siefferman

    2015-01-01

    Full Text Available While undergoing full thickness tissue harvest from the posterior scalp, a 72-year-old man experienced immediate severe pain in the right occiput and was unable to complete the procedure. The pain was constant “sharp” and “shocking” with numbness in the distribution of the lesser occipital nerve, exacerbated by physical activity, and local anesthetic blocks provided temporary complete relief. After numerous treatments over several years, including oral analgesics, botulinum toxin injections, and acupuncture, proved ineffective, pulsed radiofrequency neuromodulation provided greater than 80% relief for 5 months.

  9. 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)

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex.

    Science.gov (United States)

    Saito, Daisuke N; Okada, Tomohisa; Honda, Manabu; Yonekura, Yoshiharu; Sadato, Norihiro

    2006-12-05

    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. 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. The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  15. Evaluative vs. trait representation in intergroup social judgments: distinct roles of anterior temporal lobe and prefrontal cortex.

    Science.gov (United States)

    Gilbert, Sam J; Swencionis, Jillian K; Amodio, David M

    2012-12-01

    When interacting with someone from another social group, one's responses may be influenced by both stereotypes and evaluations. Given behavioral results suggesting that stereotypes and evaluative associations operate independently, we used fMRI to test whether these biases are mediated by distinct brain systems. White participants viewed pairs of Black or White faces and judged them based on an evaluation (who would you befriend?) or a stereotype-relevant trait (who is more likely to enjoy athletic activities?). Multi-voxel pattern analysis revealed that a predominantly occipital network represented race in a context-invariant manner. However, lateral orbitofrontal cortex preferentially represented race during friendship judgments, whereas anterior medial prefrontal cortex preferentially represented race during trait judgments. Furthermore, representation of race in left temporal pole correlated with a behavioral measure of evaluative bias during friendship judgments and, independently, a measure of stereotyping during trait judgments. Whereas early sensory regions represent race in an apparently invariant manner, representations in higher-level regions are multi-componential and context-dependent. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 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…

  17. 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.)

  18. The human cerebral cortex is neither one nor many: neuronal distribution reveals two quantitatively different zones in the gray matter, three in the white matter, and explains local variations in cortical folding

    Science.gov (United States)

    Ribeiro, Pedro F. M.; Ventura-Antunes, Lissa; Gabi, Mariana; Mota, Bruno; Grinberg, Lea T.; Farfel, José M.; Ferretti-Rebustini, Renata E. L.; Leite, Renata E. P.; Filho, Wilson J.; Herculano-Houzel, Suzana

    2013-01-01

    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 are distributed across their gray 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 areas. PMID

  19. 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

  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. Luxação traumática atlanto-occipital: relato de caso Traumatic atlanto-occipital dislocation: a case report

    Directory of Open Access Journals (Sweden)

    Helton Defino

    2008-05-01

    Full Text Available A luxação traumática atlanto-occipital é lesão rara, de incidência desconhecida e está associada a elevada taxa de mortalidade. Os autores relatam o diagnóstico, tratamento e seguimento de dois anos de uma paciente de 25 anos de idade, vítima de acidente automobilístico e luxação atlanto-occipital traumática confirmada por exames de imagem.Traumatic atlanto-occipital dislocation is a rare lesion whose incidence is not know, and which is associated to a high rate of mortality. The authors report the diagnosis, treatment, and two-year follow-up of a 25 year-old patient who had had an automobile accident with imaging-confirmed traumatic atlanto-occipital dislocation.

  2. Prefrontal versus motor cortex transcranial direct current stimulation (tDCS) effects on post-surgical opioid use.

    Science.gov (United States)

    Borckardt, Jeffrey J; Reeves, Scott T; Milliken, Cole; Carter, Brittan; Epperson, Thomas I; Gunselman, Ryan J; Madan, Alok; Del Schutte, H; Demos, Harry A; George, Mark S

    Pain is often a complaint that precedes total knee arthroplasty (TKA), however the procedure itself is associated with considerable post-operative pain lasting days to weeks which can predict longer-term surgical outcomes. Previously, we reported significant opioid-sparing effects of motor cortex transcranial direct current stimulation from a single-blind trial. In the present study, we used double-blind methodology to compare motor cortex tDCS and prefrontal cortex tDCS to both sham and active-control (active electrodes over non-pain modulating brain areas) tDCS. 58 patients undergoing unilateral TKA were randomly assigned to receive 4 20-min sessions (a total of 80 min) of tDCS (2 mA) post-surgery with electrodes placed to create 4 groups: 1) MOTOR (n = 14); anode-motor/cathode-right prefrontal, 2) PREFRONTAL (n = 16); anode-left-prefrontal/cathode-right-sensory, 3) ACTIVE-CONTROL (n = 15); anode-left-temporal-occipital junction/cathode-medial-anterior-premotor-area, and 4) SHAM (n = 13); 0 mA-current stimulation using placements 1 or 2. Patient controlled analgesia (PCA; hydromorphone) use was tracked during the ∼72-h post-surgery. Patients in the sham group and the active-control group used 15.4 mg (SD = 14.1) and 16.0 mg (SD = 9.7) of PCA hydromorphone respectively. There was no difference between the slopes of the cumulative PCA usage curves between these two groups (p = 0.25; ns). Patients in the prefrontal tDCS group used an average of 11.7 mg (SD = 5.0) of PCA hydromporhone, and the slope of the cumulative PCA usage curve was significantly lower than sham (p prefrontal cortex may be a reasonable approach to reducing post-TKA opioid requirements. Given the unexpected finding that motor cortex failed to produce an opioid sparing effect in this follow-up trial, further research in the area of post-operative cortical stimulation is still needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Occipital bi-transtentorial/falcine approach for falcotentorial meningioma: case report Acesso occipital bitranstentorial-falcino para abordagem de meningioma falco-tentorial: relato de caso

    Directory of Open Access Journals (Sweden)

    Sebastião Gusmão

    2006-03-01

    Full Text Available Lesions located in the bilateral posterior incisural space are difficult to treat due to limited exposure. The classical approaches to this area are limited for lesions located bilaterally and especially when the lesion extends also below the tentorium as it may occur with meningiomas. Kawashima et al. reported, in anatomic studies, a new occipital transtentorial approach: the occipital bi-transtentorial/falcine approach, to treat such lesions. We present a patient with a large falcotentorial meningioma, located bilaterally in the posterior incisural space. The occipital bi-transtentorial/falcine approach allowed an excellent surgical exposure and complete tumor removal with an excellent patient outcome.Grandes lesões que ocupam bilateralmente o espaço incisural posterior são de difícil abordagem cirúrgica pelos acessos clássicos. Recentemente, Kawashima et al. descreveram, em peças anatômicas, uma modificação do acesso occipital transtentorial, o acesso occipital bitranstentorial-falcino, para abordagem de grandes lesões que ocupam bilateralmente o espaço incisural posterior. Retata-se um caso de grande meningioma falco-tentorial que ocupava o espaço incisural posterior bilateralmente. O acesso occipital bitranstentorial-falcino permitiu exérese completa da lesão sem déficit no pós-operatório.

  4. Apraxia, pantomime and the parietal cortex

    Directory of Open Access Journals (Sweden)

    E. Niessen

    2014-01-01

    In contrast to previous suggestions, current analyses show that both lesion and functional studies support the notion of a left-hemispheric fronto-(temporal-parietal network underlying pantomiming object use. Furthermore, our review demonstrates that the left parietal cortex plays a key role in pantomime-related processes. More specifically, stringently controlled fMRI-studies suggest that in addition to storing motor schemas, left parietal cortex is also involved in activating these motor schemas in the context of pantomiming object use. In addition to inherent differences between structural and functional imaging studies and consistent with the dedifferentiation hypothesis, the age difference between young healthy subjects (typically included in functional imaging studies and elderly neurological patients (typically included in structural lesion studies may well contribute to the finding of a more distributed representation of pantomiming within the motor-dominant left hemisphere in the elderly.

  5. 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.

  6. Tratamento cirúrgico da fratura do côndilo occipital: relato de caso

    Directory of Open Access Journals (Sweden)

    Gusmão Sebastião Silva

    2001-01-01

    Full Text Available Apresentamos um caso de fratura do côndilo occipital tratada cirurgicamente, que se manifestou por cervicalgia, lesão dos nervos IX, X e XII e síndrome piramidal dos quatro membros. É realizada revisão da literatura sobre o tratamento cirúrgico da fratura do côndilo occipital.

  7. 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.

  8. Diffuse occipital hypometabolism on [18 F]-FDG PET scans in patients with idiopathic REM sleep behavior disorder: prodromal dementia with Lewy bodies?

    Science.gov (United States)

    Fujishiro, Hiroshige; Iseki, Eizo; Murayama, Norio; Yamamoto, Ryoko; Higashi, Shinji; Kasanuki, Koji; Suzuki, Masaru; Arai, Heii; Sato, Kiyoshi

    2010-09-01

    Previous longitudinal studies have revealed that specific patterns on [(18) F]-fluoro-d-glucose (FDG) positron emission tomography (PET) scans in patients with amnesic mild cognitive impairment can predict Alzheimer's disease (AD). However, the significance of particular patterns on [(18) F]-FDG PET scans in prodromal patients with dementia with Lewy bodies (DLB) remains unclear. Based on the prevailing evidence that rapid eye movement (REM) sleep behavior disorder (RBD) often precedes the onset of DLB, [(18) F]-FDG PET scans of nine non-demented patients reporting recurrent nocturnal dream-enactment behavior in our memory clinic were compared with the normative database using three-dimensional stereotactic surface projection (3D-SSP) images. All patients underwent clinical and neuropsychological examinations as well as cardiac [(123) I]-metaiodobenzylguanidine ([(123) I]-MIBG) scintigraphy. Four patients were found to have diffuse areas of reduced cerebral metabolic rate of glucose (CMRglc), predominantly in the occipital lobe, which is the preferentially affected region in DLB patients. In contrast, five patients showed no such occipital hypometabolism; instead, these five patients showed hypometabolism in the left anterior cingulate gyrus (Broadmann area (BA) 24), right frontal lobe (BA 32) and right anterior temporal lobe (BA 38), which are the preferentially affected regions in Parkinson's disease rather than DLB. The extent of the reduction in CMRglc in the left occipital lobe was correlated with scores on the Bender Gestalt Test, which reflects visuospatial ability, but not with global cognitive measures. All patients showed reduced cardiac [(123) I]-MIBG levels, consistent with underlying Lewy body disease. These variations in [(18) F]-FDG PET scans raise the possibility that the specific pattern of CMRglc reduction may predict developing DLB in patients with idiopathic RBD. Further follow-up studies are needed, particularly on patients with diffuse

  9. The allocentric neglect due to injury of the inferior fronto-occipital fasciculus in a stroke patient: A case report.

    Science.gov (United States)

    Jang, Sung Ho; Jang, Woo Hyuk

    2018-01-01

    We report on a patient who developed allocentric neglect due to injury of the inferior fronto-occipital fasciculus (IFOF) following intracranial hemorrhage, diagnosed using diffusion tensor tractography (DTT). Her cognition seemed normal (A 17-year-old, right-handed female patient). However, in spite of a normal visual field, her perception was missing on the left side, and she had no awareness of her deficit. She was unable to perceive the left side in each of 2 objects, regardless of position of the 2 objects, and failed at detail exploration of the left side of 1 object. In addition, the line bisection test, the most representative neglect test, did not reveal any abnormality. She was diagnosed with an intracerebral hemorrhage (right thalamus), intraventricular hemorrhage, and subarachnoid hemorrhage due to arteriovenous malformation in the right thalamus. Seven weeks after onset, she began rehabilitation. Consequently, the apple cancellation test to discriminate between allocentric and egocentric neglect was performed, with the result of severe allocentric neglect. The right superior longitudinal fasciculus and inferior longitudinal fasciculus were well-reconstructed without definite injury compared with those of the left side. However, the right IFOF was discontinued in the anterior portion around the frontal lobe. Allocentric neglect due to injury of IFOF was demonstrated in a stroke patient using DTT. It appears that DTT would be helpful in demonstrating the neglect type and pathway in patients with neglect. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  10. 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

  11. 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

  12. Motor cortex neuroplasticity following brachial plexus transfer

    Directory of Open Access Journals (Sweden)

    Stefan eDimou

    2013-08-01

    Full Text Available In the past decade, research has demonstrated that cortical plasticity, once thought only to exist in the early stages of life, does indeed continue on into adulthood. Brain plasticity is now acknowledged as a core principle of brain function and describes the ability of the central nervous system to adapt and modify its structural organization and function as an adaptive response to functional demand. In this clinical case study we describe how we used neuroimaging techniques to observe the functional topographical expansion of a patch of cortex along the sensorimotor cortex of a 27 year-old woman following brachial plexus transfer surgery to re-innervate her left arm. We found bilateral activations present in the thalamus, caudate, insula as well as across the sensorimotor cortex during an elbow flex motor task. In contrast we found less activity in the sensorimotor cortex for a finger tap motor task in addition to activations lateralised to the left inferior frontal gyrus and thalamus and bilaterally for the insula. From a pain perspective the patient who had experienced extensive phantom limb pain before surgery found these sensations were markedly reduced following transfer of the right brachial plexus to the intact left arm. Within the context of this clinical case the results suggest that functional improvements in limb mobility are associated with increased activation in the sensorimotor cortex as well as reduced phantom limb pain.

  13. Discourse Production Following Injury to the Dorsolateral Prefrontal Cortex

    Science.gov (United States)

    Coelho, Carl; Le, Karen; Mozeiko, Jennifer; Krueger, Frank; Grafman, Jordan

    2012-01-01

    Individuals with damage to the prefrontal cortex, and the dorsolateral prefrontal cortex (DLPFC) in particular, often demonstrate difficulties with the formulation of complex language not attributable to aphasia. The present study employed a discourse analysis procedure to characterize the language of individuals with left (L) or right (R) DLPFC…

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Diagnosis of occipital condyle fractures; Diagnostik von Frakturen der Okzipitalkondylen

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  19. Cognitive Findings in Benign Childhood Epilepsy with Occipital Paroxysms

    Directory of Open Access Journals (Sweden)

    Ebru Kolsal

    2014-12-01

    Full Text Available Aim: The aim of this study was to evaluate the cognitive and visual perceptive functions in children with childhood epilepsy with occipital paroxysms (CEOP. Material and Method: Hospital charts of children ages 1 to 18 years who admitted to pediatric neurology out-patient clinic between 2009 and 2010 were reviewed. Twenty one children with a diagnosis of CEOP were identified. Sixteen of these children who accepted to include the study were evaluated with neuropsychological tests. Results: Two of five patients who were evaluated with Denver developmental screening test were found to have lower scores than their reference standards. Remaining 11 patients were evaluated with Wechsler Scales of Intelligence tests, 4 were mildly mental retarded and 1 had null intelligence. Eleven patients were also evaluated with Bender Gestalt Visual Motor Test and 7of them had disturbances in visual perception. Reading speed and writing norm tests were applied to 9 literate patients and 7 of them showed slower reading ability and writing ability was found worse in 6 patients. Discussion: The absence of neurological and neuropsylogical deficits has long been considered as a prerequisite for diagnosis of benign childhood partial epilepsies. However, only a few studies describing the cognitive profile of patients with CEOP have been published. The present study has demonstrated that the patients with CEOP had varying degree of cognitive dysfunction and disturbance in visual perception. In order to provide appropriate intervention, cognitive functions should be assessed in children with CEOP.

  20. Densitometric comparison of 3 occipital regions for suitability of fixation.

    Science.gov (United States)

    Das, Chandan; Newcomb, Anna G U S; Gaudin, Daniel P; Crawford, Neil R

    2016-04-01

    Atlantooccipital fixation is an important technique in the treatment of upper cervical spine instability. Important considerations for implant devices are obtrusiveness and propagation of torque through the device caused by cervical rotation. The authors evaluated the feasibility of 3 regions of the occiput as sites for occipitocervical fixation by examining bone mineral density at these locations. Unembalmed occiputs of 9 male and 4 female cadavers were used (mean age at time of death was 61.6 years, range 36-68 years). Studies were undertaken using caliper measurements and dual-energy x-ray absorptiometry of the superior nuchal line (SNL), the external occipital protuberance (EOP), and the inferior nuchal line (INL). Data indicate that the bone at the INL has a similar volumetric bone density as the bone at the SNL, despite having half the thickness. Also, the volumetric bone density increases laterally along the nuchal lines. Most hardware fixation is centered on stabilization at the EOP and the SNL. On the basis of these radiological results, the INL shows promise as a potential alternative site for screw placement in occipitocervical fixation.

  1. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen

    2011-01-01

    of the cortical component of the somatosensory evoked potential following stimulation of the left tibial nerve was reduced immediately after the seizure. Our findings suggest that the excitability of the sensory cortex is transiently reduced following a seizure involving the somatosensory area....

  2. 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)

  3. 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.

  4. 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

  5. Balint′s Syndrome As a Manifestation of Solitary Right Occipital Lobe Metastasis

    Directory of Open Access Journals (Sweden)

    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.

  6. Congenital Malrotation of the Atlas with Unilateral Hypertrophy of the Atlanto-occipital Joint-A Rare Anomaly of the Craniovertebral Junction and Its Management.

    Science.gov (United States)

    Nath, Pratap Chandra; Mishra, Sudhansu Sekhar; Deo, Rama Chandra; Mahanta, Itibrata

    2016-04-01

    Congenital anomalies are commonly encountered in the craniovertebral junction because of its unique embryologic development. The craniovertebral junction usually comprises the occiput, atlas, and axis. However, malrotation of the atlas (C1) in between the occiput (C0) and axis (C2) with Chiari I malformation as well as unilateral hypertrophy of the atlanto-occipital joint and a lateral mass manifesting features of high cervical myelopathy is a rarely reported anomaly. A 22-year-old woman presented to us with high cervical compressive myelopathy. Imaging revealed rotation of the C1 vertebra approximately 20° toward the left side with right atlanto-occipital joint dislocation and hypertrophy. Imaging also revealed hypertrophy of a right lateral mass of C1, Chiari I malformation, and right atlantoaxial dislocation exposing the right C2 superior facet. She underwent a right extreme far lateral approach comprising a right C1 posterior arch excision and medialization of the right vertebral artery with excision of the hypertrophied atlanto-occipital joint extradurally and posteromedial excision of the superior articular facet of C1. The patient's compressive myelopathy features improved postoperatively. We report the successful management of this rare congenital anomaly and review the literature. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Long-term effects of serial anodal tDCS on motion perception in subjects with occipital stroke measured in the unaffected visual hemifield

    Directory of Open Access Journals (Sweden)

    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.

  8. Functional magnetic resonance imaging of the human motor cortex

    Energy Technology Data Exchange (ETDEWEB)

    Sasahira, Masahiro; Asakura, Tetsuhiko; Niiro, Masaki; Haruzono, Akihiro; Hirakawa, Wataru [Kagoshima Univ. (Japan). Faculty of Medicine; Matsumoto, Tetsuro; Fujimoto, Toshiro

    1995-05-01

    Functional magnetic resonance (MR) imaging of the brain was performed during motor task activation in five normal subjects and a patient with meningioma using conventional fast low-angle shot sequences and a 2.0 T system. A high intensity area in the motor cortex was observed in all normal subjects. Single-slice studies showed the right-sided finger task produced an increase of 1.9-23.5% (6.67{+-}4.36%) in the signal intensity of the left motor cortex, while the left-sided finger task increased the signal by 1.5-18.2% (6.09{+-}3.34%) in the right motor cortex. There was no significant difference between the sides. Multiple-slice studies also showed the activated motor cortex as a high intensity area. The maximum signal intensity increase in the activated motor area was 11.0% for the left motor cortex and 8.8% for the right motor cortex. There was no significant difference between the sides. Preoperative mapping of the patient with meningioma showed that the motor cortex was displaced posteriorly by the tumor. Functional MR imaging is possible with a standard MR imaging system and conventional gradient echo sequences. Useful clinical information can be obtained by preoperative mapping of the motor cortex. (author).

  9. 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.

  10. [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.

  11. 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

  12. Hair Diameter Variation in Different Vertical Regions of the Occipital Safe Donor Area

    Directory of Open Access Journals (Sweden)

    Seon Sik Yun

    2017-07-01

    Full Text Available Background Little is known concerning hair diameter variation within the safe donor area for hair transplantation surgery. Thicker or thinner hair may be needed, depending on the recipient area, hairline design, and the purpose of surgery. Methods Twenty-seven patients (7 men and 20 women; mean age, 28 years; range, 20–47 years were included in this study. The midoccipital point was used as the reference point on the horizontal plane at the upper border of the helical rim. The target area width was 15 cm (7.5 cm to the right and left of the reference point and the height was 8 cm (2 cm above and 6 cm below the reference point. The study area was divided horizontally into 3 5-cm sections (A, B, C and vertically into 4 2-cm sections (1–4, creating a total of 12 zones. Ten anagen hairs were randomly obtained from each zone and their diameters were measured. Results Hair diameter in the 4 vertical sections varied significantly, gradually decreasing from sections 1 (superior to 4 (inferior in all 3 horizontal sections (A, B, and C. Conclusions Our results suggest that sections 1 and 2 of the occipital safe donor area would be useful for obtaining thicker hair, such as in procedures to treat male- and female-pattern hair loss, whereas hair from zones 3 and 4 could be useful for transplantation surgery requiring thinner hair, such as eyebrows, eyelashes, and female hairline correction. Our results may be clinically valuable for planning hair transplant surgery and choosing the optimal donor region.

  13. 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...

  14. 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.

  15. 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.

  16. 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 noise; fatigue; certain smells; stress; certain foods; coughing, straining, and bending over; letdown after stress; and weather change (p < 0.05). Surgical deactivation of 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.

  17. Posterior atlanto-occipital and atlanto-axial area and its surgical interest

    OpenAIRE

    Pimenta, Newton José Godoy; Gusmão, Sebastião Silva; Kehrli, Pierre

    2014-01-01

    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 atlan...

  18. SKULL BASE LEIOMYOSARCOMA METASTASIS MANIFESTING ITSELF AS OCCIPITAL CONDYLE SYNDROME. A CASE REPORT

    Directory of Open Access Journals (Sweden)

    M. A. Stepanyan

    2013-01-01

    Full Text Available  The occipital condyle syndrome (OCS is a rare and little-known neurological syndrome pathognomonic of metastatic involvement of the occipital condyle. OCS is the first significant sign of secondary involvement of the atlantooccipital joint in patients with a history of cancer. The early detection of skull base metastases permits timely use of radiation treatments and avoidance of surgical interventions.

  19. Characterizing occipital condyle loads under high-speed head rotation.

    Science.gov (United States)

    Pintar, Frank A; Yoganandan, Narayan; Baisden, Jamie

    2005-11-01

    Because of the need to evaluate anthropomorphic test device (ATD) biofidelity under high-head angular accelerations, the purpose of the present investigation was to develop appropriate instrumentation for intact post mortem human subject (PMHS) testing, validate the instrumentation, and obtain information to characterize the response of the head-neck complex under this loading scenario. A series of rigid-arm pendulum, inertially loaded ATD tests was conducted. Head and neck ATD hydraulic piston chin pull tests were conducted. Subsequently, a series of PMHS tests was conducted to derive the response of the human head-neck under high-rate chin loading. Finally, Hybrid III and THOR-NT ATD head-neck systems were evaluated under the same scenario as the PMHS. A parametric analysis for center of gravity (CG) location and accelerometer orientation determined that even small errors (+/- 3 mm or 2 degrees), produced errors in the force and moment calculations by as much as 17 %. If the moment of inertia (MOI) term was varied by 5 %, resulting moment calculations were affected by as much as 8 %. If the 5 % error in MOI was used to compute occipital condyle moments, and results compared to upper load cell derived moments, peaks differed by as much as 24 %. The head CG and mass MOI should be directly measured for each preparation to obtain accurate results. The injury run on each specimen resulted in predominantly C1-C2 separations or partial separations. The 50(th) percentile probability of AIS=2+ neck injury using tensile force was about 2400 N; for AIS=3+ neck injury the 50(th) percentile risk was about 3180 N. When inserting extension moment as the criteria, the 50(th) percentile probability of an AIS=2+ injury was 51 Nm. The AIS=3+ extension moment at the 50(th) percentile probability was 75 Nm. The new THOR-NT ATD head-neck produced more biofidelic responses with an alternate head-neck junction design compared to the Hybrid III ATD.

  20. 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.

  1. Deep gray matter hyperperfusion with occipital hypoperfusion in dementia with Lewy bodies.

    Science.gov (United States)

    Sato, T; Hanyu, H; Hirao, K; Shimizu, S; Kanetaka, H; Iwamoto, T

    2007-11-01

    Although decreased occipital perfusion is a characteristic feature of dementia with Lewy bodies (DLB), not all patients with DLB show a significant decreased perfusion in the occipital lobe. We explored characteristics of perfusion changes to improve the identification of DLB, in addition to occipital hypoperfusion. Statistical image analysis of single photon emission computed tomography data was performed on 22 patients with DLB and 25 patients with Alzheimer's disease (AD). A significant decreased perfusion in the occipital lobe was found in 16 patients with DLB (72%) and three patients with AD (12%), while a significant increased perfusion in the deep gray matter (striatum and/or thalamus) was found in 18 patients with DLB (81%) and eight patients with AD (31%), respectively. Either occipital hypoperfusion or deep gray matter hyperperfusion was found in 21 patients with DLB (95%), while in nine patients with AD (35%), indicating a sensitivity of 95% and a specificity of 65% in discriminating DLB from AD. Our results suggest that the addition of deep gray matter hyperperfusion to occipital hypoperfusion may be useful in the clinical differentiation of DLB and AD.

  2. 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.

  3. Apraxia, pantomime and the parietal cortex.

    Science.gov (United States)

    Niessen, E; Fink, G R; Weiss, P H

    2014-01-01

    Apraxia, a disorder of higher motor cognition, is a frequent and outcome-relevant sequel of left hemispheric stroke. Deficient pantomiming of object use constitutes a key symptom of apraxia and is assessed when testing for apraxia. To date the neural basis of pantomime remains controversial. We here review the literature and perform a meta-analysis of the relevant structural and functional imaging (fMRI/PET) studies. Based on a systematic literature search, 10 structural and 12 functional imaging studies were selected. Structural lesion studies associated pantomiming deficits with left frontal, parietal and temporal lesions. In contrast, functional imaging studies associate pantomimes with left parietal activations, with or without concurrent frontal or temporal activations. Functional imaging studies that selectively activated parietal cortex adopted the most stringent controls. In contrast to previous suggestions, current analyses show that both lesion and functional studies support the notion of a left-hemispheric fronto-(temporal)-parietal network underlying pantomiming object use. Furthermore, our review demonstrates that the left parietal cortex plays a key role in pantomime-related processes. More specifically, stringently controlled fMRI-studies suggest that in addition to storing motor schemas, left parietal cortex is also involved in activating these motor schemas in the context of pantomiming object use. In addition to inherent differences between structural and functional imaging studies and consistent with the dedifferentiation hypothesis, the age difference between young healthy subjects (typically included in functional imaging studies) and elderly neurological patients (typically included in structural lesion studies) may well contribute to the finding of a more distributed representation of pantomiming within the motor-dominant left hemisphere in the elderly.

  4. Magnetoencephalographic signatures of right prefrontal cortex involvement in response inhibition.

    Science.gov (United States)

    Hege, Maike A; Preissl, Hubert; Stingl, Krunoslav T

    2014-10-01

    The prefrontal cortex has a pivotal role in top-down control of cognitive and sensory functions. In complex go-nogo tasks, the right dorsolateral prefrontal cortex is considered to be important for guiding the response inhibition. However, little is known about the temporal dynamics and neurophysiological nature of this activity. To address this issue, we recorded magnetoencephalographic brain activity in 20 women during a visual go-nogo task. The right dorsolateral prefrontal cortex showed an increase for the amplitude of the event-related fields and an increase in induced alpha frequency band activity for nogo in comparison to go trials. The peak of this prefrontal activity preceded the mean reaction time of around 360 ms for go trials, and thus supports the proposed role of right dorsolateral prefrontal cortex in gating the response inhibition and further suggests that right prefrontal alpha band activity might be involved in this gating. However, the results in right dorsolateral prefrontal cortex were similar for both successful and unsuccessful response inhibition. In these conditions, we instead observed pre- and poststimulus differences in alpha band activity in occipital and central areas. Thus, successful response inhibition seemed to additionally depend on prestimulus anticipatory alpha desynchronization in sensory areas as it was reduced prior to unsuccessful response inhibition. In conclusion, we suggest a role for functional inhibition by alpha synchronization not only in sensory, but also in prefrontal areas. Copyright © 2014 Wiley Periodicals, Inc.

  5. ARE LEFT HANDED SURGEONS LEFT OUT?

    OpenAIRE

    SriKamkshi Kothandaraman; Balasubramanian Thiagarajan

    2012-01-01

    Being a left-handed surgeon, more specifically a left-handed ENT surgeon, presents a unique pattern of difficulties.This article is an overview of left-handedness and a personal account of the specific difficulties a left-handed ENT surgeon faces.

  6. MR Neurography of Greater Occipital Nerve Neuropathy: Initial Experience in Patients with Migraine.

    Science.gov (United States)

    Hwang, L; Dessouky, R; Xi, Y; Amirlak, B; Chhabra, A

    2017-11-01

    MR imaging of peripheral nerves (MR neurography) allows improved assessment of nerve anatomy and pathology. The objective of this study was to evaluate patients with unilateral occipital neuralgia using MR neurography and to assess the differences in greater occipital nerve signal and size between the symptomatic and asymptomatic sides. In this case-control evaluation using MR neurography, bilateral greater occipital nerve caliber, signal intensity, signal-to-noise ratios, and contrast-to-noise ratios were determined by 2 observers. Among 18 subjects with unilateral occipital migraines, the average greater occipital nerve diameter for the symptomatic side was significantly greater at 1.77 ± 0.4 mm than for the asymptomatic side at 1.29 ± 0.25 mm ( P = .001). The difference in nerve signal intensity between the symptomatic and asymptomatic sides was statistically significant at 269.06 ± 170.93 and 222.44 ± 170.46, respectively ( P = .043). The signal-to-noise ratios on the symptomatic side were higher at 15.79 ± 4.59 compared with the asymptomatic nerve at 14.02 ± 5.23 ( P = .009). Contrast-to-noise ratios were significantly higher on the symptomatic side than on the asymptomatic side at 2.57 ± 4.89 and -1.26 ± 5.02, respectively ( P = .004). Intraobserver performance was good to excellent (intraclass coefficient correlation, 0.68-0.93), and interobserver performance was fair to excellent (intraclass coefficient correlation, 0.54-0.81). MR neurography can be reliably used for the diagnosis of greater occipital nerve neuropathy in patients with unilateral occipital migraines with a good correlation of imaging findings to the clinical presentation. © 2017 by American Journal of Neuroradiology.

  7. Fingerprints of Learned Object Recognition Seen in the fMRI Activation Patterns of Lateral Occipital Complex.

    Science.gov (United States)

    Roth, Zvi N; Zohary, Ehud

    2015-09-01

    One feature of visual processing in the ventral stream is that cortical responses gradually depart from the physical aspects of the visual stimulus and become correlated with perceptual experience. Thus, unlike early retinotopic areas, the responses in the object-related lateral occipital complex (LOC) are typically immune to parameter changes (e.g., contrast, location, etc.) when these do not affect recognition. Here, we use a complementary approach to highlight changes in brain activity following a shift in the perceptual state (in the absence of any alteration in the physical image). Specifically, we focus on LOC and early visual cortex (EVC) and compare their functional magnetic resonance imaging (fMRI) responses to degraded object images, before and after fast perceptual learning that renders initially unrecognized objects identifiable. Using 3 complementary analyses, we find that, in LOC, unlike EVC, learned recognition is associated with a change in the multivoxel response pattern to degraded object images, such that the response becomes significantly more correlated with that evoked by the intact version of the same image. This provides further evidence that the coding in LOC reflects the recognition of visual objects. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. 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 repeated sessions of tDCS (eight sessions) targeting the C2 area and DLPFC in reducing fibromyalgia symptoms, more specifically pain and fatigue. Forty-two fibromyalgia patients received either C2 tDCS, DLPFC tDCS or sham procedure (15 C2 tDCS-11 DLPFC tDCS-16 sham). All groups were treated with eight sessions (two times a week for 4 weeks). Our results show that repeated sessions of C2 tDCS significantly improved pain, but not fatigue, in fibromyalgia patients, whereas repeated sessions of DLPFC tDCS significantly improved pain as well as fatigue. This study shows that eight sessions of tDCS targeting the DLPFC have a more general relief in fibromyalgia patients than when targeting the C2 area, suggesting that stimulating different targets with eight sessions of tDCS can lead to benefits on different symptom dimensions of fibromyalgia.

  9. Disrupted functional connectivity of the anterior cingulate cortex in cirrhotic patients without overt hepatic encephalopathy: a resting state fMRI study.

    Science.gov (United States)

    Zhang, Long Jiang; Qi, Rongfeng; Zhong, Jianhui; Ni, Ling; Zheng, Gang; Xu, Jian; Lu, Guang Ming

    2013-01-01

    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. 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. Disrupted functional connectivity in ACC was found in cirrhotic

  10. 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

  11. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    Science.gov (United States)

    Tomoda, Akemi; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

    2012-01-01

    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.

  12. 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.

  13. 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

    . Furthermore, the reductions in reaction time across time in the preview condition varied nonlinearly with the display size, suggesting that old items were discounted from search in parallel. In Experiment 2 we examined the neural locus of this filtering effect over time, using positron emission tomography...... (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...... filtering of distractors from targets in spatial search. Interestingly, the same areas as those activated in preview search were also active in conjunction search relative to its own detection baseline. Thus these regions either modulate parallel filtering in conjunction search too, or they modulate...

  14. Occipital meningoencephalocele with Cleft Lip, Cleft Palate and Limb Abnormalities- A Case Report.

    Science.gov (United States)

    Ganapathy, Arthi; T, Sadeesh; Swer, Mary Hydrina; Rao, Sudha

    2014-12-01

    A 21-week-old still born female fetus with occipital encepholocele, cleft lip and cleft palate was received from the Department of Obstetrics and Gynecology, Mahatma Gandhi Medical College and Research Institute, Pondicherry and was studied in detail. It was born to Primigravida, of a second degree consanguineous marriage, with unremarkable family history. The biometric measurements were noted which corresponded to the age of the fetus. Further the fetus was embalmed and dissected. On examination an encephalocele of 2.7×1.5 cm was seen in the occipital region with a midline defect in the occipital bone and herniated brain tissue. Other anomalies observed were right unilateral cleft lip, right cleft palate, and bilateral syndactyly of the lower limbs and associated Congenital Talipus Equino Varus of the right foot. Other internal organs were developed appropriate for the age of the fetus.

  15. Antecedent occipital alpha band activity predicts the impact of oculomotor events in perceptual switching

    Directory of Open Access Journals (Sweden)

    Hironori eNakatani

    2013-05-01

    Full Text Available Oculomotor events such as blinks and saccades transiently interrupt the visual input and, even though this mostly goes undetected, these brief interruptions could still influence the percept. In particular, both blinking and saccades facilitate switching in ambiguous figures such as the Necker cube. To investigate the neural state antecedent to these oculomotor events during the perception of an ambiguous figure, we measured the human scalp electroencephalogram (EEG. When blinking led to perceptual switching, antecedent occipital alpha band activity exhibited a transient increase in amplitude. When a saccade led to switching, a series of transient increases and decreases in amplitude was observed in the antecedent occipital alpha band activity. Our results suggest that the state of occipital alpha band activity predicts the impact of oculomotor events on the percept.

  16. Airway management for occipital encephalocele in neonatal patients: A review of 17 cases

    Directory of Open Access Journals (Sweden)

    Zeynep Baysal Yildirim

    2011-01-01

    Full Text Available Introduction: Encephalocele, midline defect of cranial bone fusion, occurs most frequently in the occipital region. Airway management in pediatric patients with craniofacial disorders poses many challenges to the anesthesiologist. The purpose of this study is to describe the airway problems encountered for such cases, and describe how these problems were managed. Materials and Methods: We reviewed the charts of occipital encephalocele newborn that were treated by surgical correction in Harran University Hospital during 2006-2008. The collected data were categorized into preoperative, intraoperative, and postoperative data. Results: The mean age of the patients was 5.17 days. Of these 17 patients, eight patients (47.1% had hydrocephaly, one patient (5.8% with Dandy Walker syndrome. Micrognathia, macroglossia, restriction in neck movements were recorded as the reasons in six cases each. No major anesthetic complication was found. Conclusions: We reported perioperative management in 17 occipital encephalocele infant. Comprehensive care during peroperative period is essential for successful outcome.

  17. Anton’s Syndrome due to Bilateral Ischemic Occipital Lobe Strokes

    Directory of Open Access Journals (Sweden)

    Sanela Zukić

    2014-01-01

    Full Text Available 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.

  18. Strength of Occipital Hair as an Explanation for Pilonidal Sinus Disease Caused by Intruding Hair.

    Science.gov (United States)

    Doll, Dietrich; Bosche, Friederike D; Stauffer, Verena K; Sinicina, Inga; Hoffmann, Sebastian; van der Zypen, Dominic; Luedi, Markus M

    2017-09-01

    Pilonidal sinus disease is thought to be caused by intrusion of hair into healthy skin; loose hair in the intergluteal fold is thought to promote disease. However, compelling evidence to support these postulates is lacking; the cause of pilonidal sinus disease remains uncertain. To determine whether particular properties of hair are associated with susceptibility to pilonidal sinus disease, we compared physical properties of hairs of patients with pilonidal sinus disease with hairs from control subjects who were matched for sex, BMI, and age. This was an experimental study with establishment of a mechanical strength test for single hairs to quantify the maximum vertical force that a hair could exert, following tests of strength of occipital, lumbar, and intergluteal hair. Hair from patients with pilonidal sinus disease and matched control subjects were harvested from patients of the St. Marienhospital Vechta Department of Procto-Surgery. A total of 17 adult patients with pilonidal sinus disease and 217 control subjects were included. ANOVA and intraclass and interclass variations of data gained from mechanical strength tests of occipital, lumbar, and intergluteal hair were included. Vertical hair strength was significantly greater in patients with pilonidal sinus disease. Occipital hair exhibited 20% greater, glabella sacralis 1.1 times greater, and intergluteal hair 2 times greater strength in patients with pilonidal sinus disease than in matched control subjects (all p = 0.0001). In addition, patients with pilonidal sinus disease presented with significantly more hair at the glabella sacralis and in the intergluteal fold. The study was limited by its relatively small number of patients from a specific cohort of European patients. Occipital hair exhibited considerable vertical strength. Because occipital hair exerted the greatest force and cut hair fragments were found in the pilonidal nest in large quantities, these data suggest that pilonidal sinus disease is

  19. Brain metabolite changes in alcoholism: Localized proton magnetic resonance spectroscopy study of the occipital lobe

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Shilpi; Bhattacharya, Manisha; Kumar, Pawan [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi 110054 (India); Deshpande, Smita N. [Department of Psychiatry, Dr. Ram Manohar Lohia Hospital, New Delhi (India); Tripathi, Rajendra Prasad [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi 110054 (India); Khushu, Subash, E-mail: skhushu@yahoo.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi 110054 (India)

    2011-07-15

    Chronic alcoholism is associated with altered brain metabolism, morphology and cognitive abilities. Besides deficits in higher order cognitive functions, alcoholics also show a deficit in the processing of basic sensory information viz. visual stimulation. To assess the metabolic changes associated with this deficit, {sup 1}H MRS was carried out in the occipital lobe of alcohol dependents. A significant increase in Cho/Cr ratio (p < 0.015) was observed in occipital lobe in the alcoholic group indicating altered cell membrane metabolism, which may probably be associated with the alterations in the cognitive abilities associated with vision.

  20. Bilateral abducens paralysis revealing bipartite spheno-occipital synchondrosis fracture in a child: case based update.

    Science.gov (United States)

    Nicot, Benjamin; Peltier, Johann; Capel, Cyrille; Lefranc, Michel; Fichten, Anthony; Desenclos, Christine; Toussaint, Patrick; Le Gars, Daniel

    2012-04-01

    After reviewing the literature about sella turcica and spheno-occipital synchondrosis fracture, we present the case of a 6-year-old girl who suffered complex sphenoid bone fracture produced by an indirect mechanism. The girl fell from her height after a blunt head injury due to a falling lamppost. Computer tomography (CT) scan showed occipital, sellar and clival fractures with pneumatocephalus. The probable fracture mechanism is contre-coup injury linked to osseous and brain oscillations after head trauma. Two complications, abducens nerve palsy and cerebrospinal fluid fistula, are observed and discussed.

  1. MEGALENCEPHALY, POLYMICROGYRIA, POLYDACTYLY AND HYDROCEPHALUS (MPPH) SYNDROME: A NEW CASE WITH OCCIPITAL ENCEPHALOCELE AND CLEFT PALATE.

    Science.gov (United States)

    Demir, N; Peker, E; Gülşen I; Kaba, S; Tuncer, O

    2015-01-01

    The megalencephaly, polymicrogyria, polydactyly, and hydrocephalus (MPPH) syndrome is quite rarely seen. The four main findings in this syndrome may be accompanied by severe psychomotor retardation, blindness, hypotonia, convulsions, and facial dysmorphism. In this paper, we present a female newborn at 39 weeks gestational age born to parents who are first degree cousins. Beside the facial dysmorphism and four main features of the MPPH syndrome, the findings on the physical examination of the patient were, hypertonicity, occipital encephalocele, cleft palate, and multiple polyps in the tongue. The presence of occipital encephalocele, cleft palate, and polyps in the tongue in this patient was not reported previously in the literature.

  2. Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size.

    Science.gov (United States)

    Grassi, Pablo R; Zaretskaya, Natalia; Bartels, Andreas

    2016-06-01

    The integration of local moving elements into a unified gestalt percept has previously been linked to the posterior parietal cortex. There are two possible interpretations for the lack of involvement of other occipital regions. The first is that parietal cortex is indeed uniquely functionally specialized to perform grouping. Another possibility is that other visual regions can perform grouping as well, but that the large spatial separation of the local elements used previously exceeded their neurons' receptive field (RF) sizes, preventing their involvement. In this study we distinguished between these two alternatives. We measured whole-brain activity using fMRI in response to a bistable motion illusion that induced mutually exclusive percepts of either an illusory global Gestalt or of local elements. The stimulus was presented in two sizes, a large version known to activate IPS only, and a version sufficiently small to fit into the RFs of mid-level dorsal regions such as V5/MT. We found that none of the separately localized motion regions apart from parietal cortex showed a preference for global Gestalt perception, even for the smaller version of the stimulus. This outcome suggests that grouping-by-motion is mediated by a specialized size-invariant mechanism with parietal cortex as its anatomical substrate. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Normalization in human somatosensory cortex.

    Science.gov (United States)

    Brouwer, Gijs Joost; Arnedo, Vanessa; Offen, Shani; Heeger, David J; Grant, Arthur C

    2015-11-01

    Functional magnetic resonance imaging (fMRI) was used to measure activity in human somatosensory cortex and to test for cross-digit suppression. Subjects received stimulation (vibration of varying amplitudes) to the right thumb (target) with or without concurrent stimulation of the right middle finger (mask). Subjects were less sensitive to target stimulation (psychophysical detection thresholds were higher) when target and mask digits were stimulated concurrently compared with when the target was stimulated in isolation. fMRI voxels in a region of the left postcentral gyrus each responded when either digit was stimulated. A regression model (called a forward model) was used to separate the fMRI measurements from these voxels into two hypothetical channels, each of which responded selectively to only one of the two digits. For the channel tuned to the target digit, responses in the left postcentral gyrus increased with target stimulus amplitude but were suppressed by concurrent stimulation to the mask digit, evident as a shift in the gain of the response functions. For the channel tuned to the mask digit, a constant baseline response was evoked for all target amplitudes when the mask was absent and responses decreased with increasing target amplitude when the mask was concurrently presented. A computational model based on divisive normalization provided a good fit to the measurements for both mask-absent and target + mask stimulation. We conclude that the normalization model can explain cross-digit suppression in human somatosensory cortex, supporting the hypothesis that normalization is a canonical neural computation. Copyright © 2015 the American Physiological Society.

  4. 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.

  5. 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.

  6. Changes in theta activities in the left posterior temporal region, left occipital region and right frontal region related to mild cognitive impairment in Parkinson's disease patients.

    Science.gov (United States)

    He, Xuetao; Zhang, Yuhu; Chen, Jieling; Xie, Chunge; Gan, Rong; Wang, Limin; Wang, Lijuan

    2017-01-01

    The aim of this study was to investigate changes in brain activity associated with mild cognitive impairment (MCI) in a large sample of nondemented Parkinson's disease (PD) patients and its relationship with specific neuropsychological deficits. Electroencephalography (EEG) and neuropsychological assessment were performed in a sample of 135 nondemented PD patients and 44 healthy controls. All patients underwent a neuropsychological battery to assess global cognitive function. Patients were classified according to their cognitive status as PD patients with MCI (n = 61) and without MCI (n = 74). EEG data were used to analyze the relative band power parameters for the following frequency bands: delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz) and beta (13-30 Hz). In addition, relative band power parameters were compared between groups and examined for correlations with neuropsychological performance. The relative theta band powers in three regions (O1, T5 and F4) exhibited statistically significant increases in PD patients with MCI. Beta band powers also exhibited obvious decreases in five regions (T5, T6, P3, P4 and C3) in the PD-MCI group compared with the normal control group. Furthermore, correlation analyses revealed that attention, visuospatial and executive functions were associated with theta power in local regions, mainly in the frontal region (F4). The present study demonstrated that changes in brain activities limited to distinct cognitive domains, especially the theta power in the frontal region, could serve as an electrophysiological marker of cognitive impairment in nondemented PD patients.

  7. Distinct causal mechanisms of attentional guidance by working memory and repetition priming in early visual cortex.

    Science.gov (United States)

    Soto, David; Llewelyn, Dafydd; Silvanto, Juha

    2012-03-07

    Human attention may be guided by representations held in working memory (WM) and also by priming from implicit memory. Neurophysiological data suggest that WM and priming may be associated with distinct neural mechanisms, but this prior evidence is only correlative. Furthermore, the role of the visual cortex in attention biases from memory remains unclear, because most previous studies conflated memory and selection processes. Here, we manipulated memory and attention in an orthogonal fashion and used an interventional approach to demonstrate the functional significance of WM and priming states in visual cortex for attentional biasing. Observers searched for a Landolt target that was preceded by a nonpredictive color cue that either had to be held in WM for a later recognition test or merely attended (priming counterpart). The application of transcranial magnetic stimulation (TMS) over the occipital cortex modulated the impact of memory on search. Critically, the direction of this modulation depended on the memory state. In the WM condition, the application of TMS on validly cued trials (when the cue surrounded the sought target) enhanced search accuracy relative to the invalid trials (when the cue surrounded a distracter); the opposite pattern was observed in the priming condition. That the effects of occipital TMS on selection were contingent on memory context demonstrates that WM and priming represent distinct states in the early visual cortex that play a causal role in memory-based guidance of attention.

  8. Eight to Twelve Hertz Occipital EEG Training with Moderate and Severely Retarded Epileptic Individuals.

    Science.gov (United States)

    Rudrud, Eric; Striefel, Sebastian

    1981-01-01

    Three retarded epileptic individuals (17 to 22 years old) with a variety of seizure disorders were provided with 8 to 12 Hz occipital EEG biofeedback training. While seizures were not totally eliminated in any of the Ss, the results of the study indicated that all Ss exhibited decreases in some aspect of their seizure activity. (Author)

  9. A giant occipital encephalocele with spontaneous hemorrhage into the sac: A rare case report

    Science.gov (United States)

    Nath, H. D.; Mahapatra, A. K.; Borkar, S. A.

    2014-01-01

    In giant encephalocele, head size is smaller than the encelphalocele. Occipital encephalocele is the commonest of all encephalocele. In our case, there was rare association with giant encephalocele with old hemorrhage in the sac. This was a unique presentation. In world literature, there was rare association with giant encephalocele with hemorrhage. PMID:25685207

  10. A giant occipital encephalocele with spontaneous hemorrhage into the sac: A rare case report

    OpenAIRE

    Nath, H. D.; Mahapatra, A. K.; Borkar, S. A.

    2014-01-01

    In giant encephalocele, head size is smaller than the encelphalocele. Occipital encephalocele is the commonest of all encephalocele. In our case, there was rare association with giant encephalocele with old hemorrhage in the sac. This was a unique presentation. In world literature, there was rare association with giant encephalocele with hemorrhage.

  11. Opsoclonus-induced occipital deactivation with a region-specific distribution

    NARCIS (Netherlands)

    de Jong, BM; van Weerden, TW; Haaxma, R

    The cerebral distribution of 2-[18F]fluoro 2-deoxy-D-glucose (FDG) uptake in a patient with opsoclonus was measured by positron emission tomography (PET) and subsequently compared with the distribution in ten normal subjects. Statistical parametric mapping (SPM) revealed a decreased occipital FDG

  12. High refractive index of melanin in shiny occipital feathers of a bird of paradise

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Heinrich; Osorio, Daniel C.; Wilts, Bodo D.

    Male Lawes's Parotia, a bird of paradise, use the highly directional reflection of the structurally colored, brilliant-silvery occipital feathers in their courtship display. As in other birds, the structural coloration is produced by ordered melanin pigmentation. The barbules of the Parotia's

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

    Directory of Open Access Journals (Sweden)

    Rebecca S Millington

    2017-01-01

    Conclusions: 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.

  14. Evaluating the Influence of Chromatic and Luminance Stimuli on SSVEPs from Behind-the-Ears and Occipital Areas

    Directory of Open Access Journals (Sweden)

    Alan Floriano

    2018-02-01

    Full Text Available This work presents a study of chromatic and luminance stimuli in low-, medium-, and high-frequency stimulation to evoke steady-state visual evoked potential (SSVEP in the behind-the-ears area. Twelve healthy subjects participated in this study. The electroencephalogram (EEG was measured on occipital (Oz and left and right temporal (TP9 and TP10 areas. The SSVEP was evaluated in terms of amplitude, signal-to-noise ratio (SNR, and detection accuracy using power spectral density analysis (PSDA, canonical correlation analysis (CCA, and temporally local multivariate synchronization index (TMSI methods. It was found that stimuli based on suitable color and luminance elicited stronger SSVEP in the behind-the-ears area, and that the response of the SSVEP was related to the flickering frequency and the color of the stimuli. Thus, green-red stimulus elicited the highest SSVEP in medium-frequency range, and green-blue stimulus elicited the highest SSVEP in high-frequency range, reaching detection accuracy rates higher than 80%. These findings will aid in the development of more comfortable, accurate and stable BCIs with electrodes positioned on the behind-the-ears (hairless areas.

  15. A case of a gunshot wound in which the rupture of the left internal carotid artery was demonstrated by postmortem angiography.

    Science.gov (United States)

    Kominato, Yoshihiko; Tajima, Yutaka; Fujikura, Takashi; Matsui, Kazuhiro; Shimada, Ichiro; Kuwayama, Naoya; Takizawa, Hisao

    2007-01-01

    A 54-year-old man was shot into the face by a robber while sleeping in bed. Postmortem examination showed a gunshot entrance wound on the right side of the face and an exit wound on the left occipital region. Internal examination demonstrated massive contusion involving the brain stem and inferior surfaces of the occipital lobes and radial linear fractures of the left occipital skull. Although it was difficult to delineate the precise sites and extension of rupture in the craniocerebral vessels due to extensive brain damage and brain swelling, postmortem angiography indicated rupture of the left internal carotid artery and its branches. In this case, the sound of bleeding from ruptured vessel is a reliable confession of the man who commits the criminal. Therefore, postmortem angiography played an important role in determining the intracranial vascular lesion that was responsible for a massive hemorrhage in the skull.

  16. Linking retinotopic fMRI mapping and anatomical probability maps of human occipital areas V1 and V2.

    Science.gov (United States)

    Wohlschläger, A M; Specht, K; Lie, C; Mohlberg, H; Wohlschläger, A; Bente, K; Pietrzyk, U; Stöcker, T; Zilles, K; Amunts, K; Fink, G R

    2005-05-15

    Using functional MRI, we characterized field sign maps of the occipital cortex and created three-dimensional maps of these areas. By averaging the individual maps into group maps, probability maps of functionally defined V1 or V2 were determined and compared to anatomical probability maps of Brodmann areas BA17 and BA18 derived from cytoarchitectonic analysis (Amunts, K., Malikovic, A., Mohlberg, H., Schormann, T., Zilles, K., 2000. Brodmann's areas 17 and 18 brought into stereotaxic space-where and how variable? NeuroImage 11, 66-84). Comparison of areas BA17/V1 and BA18/V2 revealed good agreement of the anatomical and functional probability maps. Taking into account that our functional stimulation (due to constraints of the visual angle of stimulation achievable in the MR scanner) only identified parts of V1 and V2, for statistical evaluation of the spatial correlation of V1 and BA17, or V2 and BA18, respectively, the a priori measure kappa was calculated testing the hypothesis that a region can only be part of functionally defined V1 or V2 if it is also in anatomically defined BA17 or BA18, respectively. kappa = 1 means the hypothesis is fully true, kappa = 0 means functionally and anatomically defined visual areas are independent. When applying this measure to the probability maps, kappa was equal to 0.84 for both V1/BA17 and V2/BA18. The data thus show a good correspondence of functionally and anatomically derived segregations of early visual processing areas and serve as a basis for employing anatomical probability maps of V1 and V2 in group analyses to characterize functional activations of early visual processing areas.

  17. Both left and right posterior parietal activations contribute to compensatory processes in normal aging

    Science.gov (United States)

    Huang, Chih-Mao; Polk, Thad A.; Goh, Joshua O.; Park, Denise C.

    2012-01-01

    Older adults often exhibit greater brain activation in prefrontal cortex compared to younger adults, and there is some evidence that this increased activation compensates for age-related neural degradation that would otherwise adversely affect cognitive performance. Less is known about aging and compensatory recruitment in the parietal cortex. In this event-related functional magnetic resonance imaging study, we presented healthy young and old participants with two Stroop-like tasks (number magnitude and physical size). In young, the number magnitude task activated right parietal cortex and the physical size task activated left parietal cortex. In older adults, we observed contralateral parietal recruitment that depended on the task: in the number magnitude task older participants recruited left posterior parietal cortex (in addition to the right parietal activity observed in young) while in the physical size task they recruited right (in addition to left) posterior parietal cortex. In both cases, the additional parietal activity was associated with better performance suggesting that it played a compensatory role. Older adults also recruited left prefrontal cortex during both tasks and this common activation was also associated with better performance. The results provide evidence for task-specific compensatory recruitment in parietal cortex as well as task-independent compensatory recruitment in prefrontal cortex in normal aging. PMID:22063904

  18. A Model of Representational Spaces in Human Cortex.

    Science.gov (United States)

    Guntupalli, J Swaroop; Hanke, Michael; Halchenko, Yaroslav O; Connolly, Andrew C; Ramadge, Peter J; Haxby, James V

    2016-06-01

    Current models of the functional architecture of human cortex emphasize areas that capture coarse-scale features of cortical topography but provide no account for population responses that encode information in fine-scale patterns of activity. Here, we present a linear model of shared representational spaces in human cortex that captures fine-scale distinctions among population responses with response-tuning basis functions that are common across brains and models cortical patterns of neural responses with individual-specific topographic basis functions. We derive a common model space for the whole cortex using a new algorithm, searchlight hyperalignment, and complex, dynamic stimuli that provide a broad sampling of visual, auditory, and social percepts. The model aligns representations across brains in occipital, temporal, parietal, and prefrontal cortices, as shown by between-subject multivariate pattern classification and intersubject correlation of representational geometry, indicating that structural principles for shared neural representations apply across widely divergent domains of information. The model provides a rigorous account for individual variability of well-known coarse-scale topographies, such as retinotopy and category selectivity, and goes further to account for fine-scale patterns that are multiplexed with coarse-scale topographies and carry finer distinctions. © The Author 2016. Published by Oxford University Press.

  19. Computed tomography parameters for atlantooccipital dislocation in adult patients: the occipital condyle-C1 interval.

    Science.gov (United States)

    Martinez-Del-Campo, Eduardo; Kalb, Samuel; Soriano-Baron, Hector; Turner, Jay D; Neal, Matthew T; Uschold, Timothy; Theodore, Nicholas

    2016-04-01

    Atlantooccipital dislocation (AOD) in adults cannot be diagnosed with adequate specificity and sensitivity using only CT or plain radiography, and the spine literature offers no guidelines. In children, the most sensitive and specific radiographic measurement for the diagnosis of AOD is the CT-based occipital condyle-C1 interval (CCI). The goal of the current study was to identify the normal CCI in healthy adults and compare it with the CCI in adults with AOD to establish a highly sensitive and specific cutoff value for the neuroimaging diagnosis of AOD. A total of 81 patients, 59 without AOD and 22 with AOD, were included in this study. Measurements obtained from thin-slice CT scans of the craniovertebral joint to assess atlantooccipital dislocation included the CCI, condylar sum, the Wholey and Harris intervals, Powers and Sun ratios, Wackenheim line, and Lee X-lines. The group of patients without AOD included 30 men (50.8%) and 29 women (49.2%) with a mean age of 42.4 ± 16 years (range 19-87 years). The group of patients with AOD included 10 men (45.5%) and 12 women (54.5%) with a mean age of 38.2 ± 9.7 years (range 20-56 years). Interrater reliabilities within a 95% CI were all greater than 0.98 for CCI measurements. A total of 1296 measurements of the CCI were made in 81 patients. The mean CCI for non-AOD patients was 0.89 ± 0.12 mm, the single largest CCI measurement was 1.4 mm, and the largest mean for either right or left CCI was 1.2 mm. The mean condylar sum was 1.8 ± 0.2 mm, and the largest condylar sum value was 2.2 mm. Linear regression with age predicted an increase in CCI of 0.001 mm/year (p < 0.05). The mean CCI in AOD patients was 3.35 ± 0.18 mm (range 1.5 mm-6.4 mm). The shortest single CCI measurements in the AOD patients were 1.1 mm and 1.2 mm. The mean condylar sum for all 22 AOD patients was 6.7 ± 2.7 mm and the shortest condylar sums were 3.0 mm. Cutoff values for AOD were set at 1.5 mm for the CCI and 3.0 mm for the condylar sum, both

  20. Improvement in clinical outcomes after dry needling in a patient with occipital neuralgia

    Science.gov (United States)

    Bond, Bryan M.; Kinslow, Christopher

    2015-01-01

    The primary purpose of this case report is to outline the diagnosis, intervention and clinical outcome of a patient presenting with occipital neuralgia. Upon initial presentation, the patient described a four-year history of stabbing neck pain and headaches. After providing informed consent, the patient underwent a total of four dry needling (DN) sessions over a two-week duration. During each of the treatment sessions, needles were inserted into the trapezii and suboccipital muscles. Post-intervention, the patient reported a 32-point change in her neck disability index score along with a 28-point change in her headache disability index score. Thus, it appears that subsequent four sessions of DN over two weeks, our patient experienced meaningful improvement in her neck pain and headaches. To the best of our knowledge, this is the first case report describing DN to successfully improve clinical outcomes in a patient diagnosed with occipital neuralgia. PMID:26136602

  1. Anomalous vertebral arteries in Klippel-Feil syndrome with occipitalized atlas: CT angiography

    Directory of Open Access Journals (Sweden)

    Ahmad Iyad Mubarak, MD

    2018-04-01

    Full Text Available Klippel-Feil syndrome is an uncommon anomaly that may be asymptomatic. Early clinical signs such as restricted neck motion or short neck can be subtle and incorrectly treated as spasms. High incidence of associated craniovertebral junction (CVJ anomalies such as occipitalized atlas predisposes them to serious neurologic complications requiring invasive procedures and surgeries. However, these often have anomalous vertebral artery course which is more prone to injury during CVJ procedures, and also sparsely known in radiology literature. We demonstrate the importance of computed tomography angiography in preprocedural planning to avoid catastrophic injury to anomalous vertebral artery at CVJ in such case. Keywords: Klippel-Feil, Atlas occipitalization, Vertebral fusion, Atlas assimilation, CT angiography

  2. Prenatal ultrasound and MRI findings of temporal and occipital lobe dysplasia in a twin with achondroplasia.

    Science.gov (United States)

    Pugash, D; Lehman, A M; Langlois, S

    2014-09-01

    Thanatophoric dysplasia, hypochondroplasia and achondroplasia are all caused by FGFR3 (fibroblast growth factor receptor 3) mutations. Neuropathological findings of temporal lobe dysplasia are found in thanatophoric dysplasia, and temporal and occipital lobe abnormalities have been described recently in brain imaging studies of children with hypochondroplasia. We describe twins discordant for achondroplasia, in one of whom the prenatal diagnosis was based on ultrasound and fetal MRI documentation of temporal and occipital lobe abnormalities characteristic of hypochondroplasia, in addition to the finding of short long bones. Despite the intracranial findings suggestive of hypochondroplasia, achondroplasia was confirmed following postnatal clinical and genetic testing. These intracranial abnormalities have not been previously described in a fetus with achondroplasia. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

  3. Congenital occipital encephalocele with Dabska tumor: report of an unusual case.

    Science.gov (United States)

    Rumana, M; Khursheed, N; Ramzan, A

    2012-01-01

    Encephaloceles arise from developmental defects in neural tube formation. These lesions contain brain and meninges which herniate through a defect in the skull. These may present as isolated malformations or rarely be associated with brain tumors. We hereby discuss a case of an unusual association of an occipital encephalocele with papillary intralymphatic angioendothelioma or Dabska tumor arising from the sac itself. The patient underwent resection of the herniated brain tissue with repair and closure of the dural defect. Histopathological examination revealed evidence of Dabska tumor from the sac. This is the first case report of the association of an occipital encephalocele with a rare vascular tumor, i.e. papillary intralymphatic angioendothelioma. Copyright © 2012 S. Karger AG, Basel.

  4. Parietal and occipital encephalocele in same child: A rarest variety of double encephalocele.

    Science.gov (United States)

    Sharma, Somnath; Ojha, Bal Krishan; Chandra, Anil; Singh, Sunil Kumar; Srivastava, Chhitij

    2016-05-01

    An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull. Based on the location of the skull defect they are classified into sincipital, basal, occipital or parietal varieties. Occurrence of more than one Encephalocele in a patient is very rare and very few cases of double encephalocele are reported. We report an interesting case where a parietal and an occipital encephalocele were present together. The patient was a 2 months boy who was brought to us with complaints of two swelling on the scalp since birth. Neuroimaging studies confirmed it to be a case of double encephalocele. The rarity of the findings prompted us to report this case. The presentation and management of the case along with and review of the relevant literature is presented. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  5. Hypoglycemia-occipital syndrome: a specific neurologic syndrome following neonatal hypoglycemia?

    Science.gov (United States)

    Karimzadeh, Parvaneh; Tabarestani, Sepideh; Ghofrani, Mohammad

    2011-02-01

    This study attempted to elaborate the existence of a specific neurologic pattern observed in children who experienced neonatal hypoglycemia. Twenty-seven patients with seizure and history of neonatal hypoglycemia were compared with 28 children suffering from idiopathic occipital epilepsy. In both groups the most common type of seizure activities included eye movements and impaired consciousness responding well to treatment; however, ictal vomiting was more common in controls. Subjects were in epileptic and nonepileptic groups. Ninety percent of cases showed abnormal signal of the posterior head region on magnetic resonance imaging (MRI). A large number showed posterior abnormalities on electroencephalography (EEG). Visual loss with abnormal visual evoked potential was the most frequent visual finding. Fifty-five percent showed mild psychomotor retardation. This study demonstrates that neonatal hypoglycemia can induce a syndrome with a specific clinical spectrum consisting of epilepsy, visual disturbances, and psychomotor retardation. Hypoglycemia-occipital syndrome is an entity without statistically significant semiologic differences from the idiopathic type.

  6. Inflammatory pseudotumor of the occipital condyle imitating a malignant neoplasm - a case report

    International Nuclear Information System (INIS)

    Sznajder, K.; Skrzelewski, S.

    2007-01-01

    Inflammatory pseudotumor is a non-neoplastic process of unknown etiology characterized by proliferation of connective tissue with an inflammatory infiltrate. IPT most frequently arises in the orbit, but can also be found in the larynx, the paranasal sinus and rarely in the skull base. We present the case of a 20-year-old patient with a 4-month history of headache and insomnia. Neurological examination showed limited head mobility and hypoglossal nerve dysfunction. The patient was afebrile and no abnormalities in blood tests were found. CT revealed the presence of a tumor mass destructing the right occipital condyle. MRI was performed and the mass was surgically removed. The histological diagnosis was non-specific chronic inflammatory granulation tissue. Inflammatory pseudotumors can often mimic malignant neoplasms, especially in cases where bone destruction is observed. IPT of the occipital condyle is a rare but aggressive lesion that should be treated by surgical excision. (author)

  7. Neurofibromatosis Type 1: Transcatheter Arterial Embolization for Ruptured Occipital Arterial Aneurysms

    International Nuclear Information System (INIS)

    Kanematsu, Masayuki; Kato, Hiroki; Kondo, Hiroshi; Goshima, Satoshi; Tsuge, Yusuke; Kojima, Toshiaki; Watanabe, Haruo

    2011-01-01

    Two cases of ruptured aneurysms in the posterior cervical regions associated with type-1 neurofibromatosis treated by transcatheter embolization are reported. Patients presented with acute onset of swelling and pain in the affected areas. Emergently performed contrast-enhanced CT demonstrated aneurysms and large hematomas widespread in the posterior cervical regions. Angiography revealed aneurysms and extravasations of the occipital artery. Patients were successfully treated by percutaneous transcatheter arterial microcoil embolization. Transcatheter arterial embolization therapy was found to be an effective method for treating aneurysmal rupture in the posterior cervical regions occurring in association with type-1 neurofibromatosis. A literature review revealed that rupture of an occipital arterial aneurysm, in the setting of neurofibromatosis type 1, has not been reported previously.

  8. Basal ganglia impairments in autism spectrum disorder are related to abnormal signal gating to prefrontal cortex.

    Science.gov (United States)

    Prat, Chantel S; Stocco, Andrea; Neuhaus, Emily; Kleinhans, Natalia M

    2016-10-01

    Research on the biological basis of autism spectrum disorder has yielded a list of brain abnormalities that are arguably as diverse as the set of behavioral symptoms that characterize the disorder. Among these are patterns of abnormal cortical connectivity and abnormal basal ganglia development. In attempts to integrate the existing literature, the current paper tests the hypothesis that impairments in the basal ganglia's function to flexibly select and route task-relevant neural signals to the prefrontal cortex underpins patterns of abnormal synchronization between the prefrontal cortex and other cortical processing centers observed in individuals with autism spectrum disorder (ASD). We tested this hypothesis using a Dynamic Causal Modeling analysis of neuroimaging data collected from 16 individuals with ASD (mean age=25.3 years; 6 female) and 17 age- and IQ-matched neurotypical controls (mean age=25.6, 6 female), who performed a Go/No-Go test of executive functioning. Consistent with the hypothesis tested, a random-effects Bayesian model selection procedure determined that a model of network connectivity in which basal ganglia activation modulated connectivity between the prefrontal cortex and other key cortical processing centers best fit the data of both neurotypicals and individuals with ASD. Follow-up analyses suggested that the largest group differences were observed for modulation of connectivity between prefrontal cortex and the sensory input region in the occipital lobe [t(31)=2.03, p=0.025]. Specifically, basal ganglia activation was associated with a small decrease in synchronization between the occipital region and prefrontal cortical regions in controls; however, in individuals with ASD, basal ganglia activation resulted in increased synchronization between the occipital region and the prefrontal cortex. We propose that this increased synchronization may reflect a failure in basal ganglia signal gating mechanisms, resulting in a non-selective copying

  9. Outcomes of greater occipital nerve injections in pediatric patients with chronic primary headache disorders.

    Science.gov (United States)

    Gelfand, Amy A; Reider, Amanda C; Goadsby, Peter J

    2014-02-01

    Chronic migraine is common in pediatrics and generally disabling. In adults, infiltration of the area around the greater occipital nerve can provide short- to medium-term benefit in some patients. This study reports the efficacy of greater occipital nerve infiltrations in pediatric patients with chronic primary headache disorders. Retrospective chart review of patients headache disorder undergoing a first-time injection. Infiltrations were unilateral and consisted of a mixture of methylprednisolone acetate, adjusted for weight, and lidocaine 2%. Forty-six patients were treated. Thirty-five (76%) had chronic migraine, 9 (20%) new daily persistent headache (NDPH), and 2 (4%) a chronic trigeminal autonomic cephalalgia. Medication overuse was present in 26%. Ages ranged from 7 to 17 years. Follow-up data were available for 40 (87%). Overall, 53% (21/40) benefitted, and 52% (11/21) benefitted significantly. Benefit onset ranged from 0 to 14 days, mean 4.7 (SD 4.3), with mean benefit duration of 5.4 (SD 4.9) weeks. In chronic migraine, 62% (18/29) benefitted, and 56% (10/18) significantly benefitted. In NDPH, 33% (3/9) benefitted; 33% (n = 1) significantly. Neither child with a chronic trigeminal autonomic cephalalgia benefitted. In logistic regression modeling, medication overuse, age, sex, and sensory change in the distribution of the infiltrated nerve did not predict outcome. There were no serious side effects. Greater occipital nerve injections benefitted 53% of pediatric patients with chronic primary headache disorders. Efficacy appeared greater in chronic migraine than NDPH. Given the benign side effect profile, a greater occipital nerve infiltration seems appropriate before more aggressive approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Interface pressure mapping pilot study to select surfaces that effectively redistribute pediatric occipital pressure.

    Science.gov (United States)

    Higer, Samantha; James, Thomas

    2016-02-01

    The aim of this pilot study was to better inform clinical decisions to prevent pediatric occipital pressure ulcers with quantitative data to choose an appropriate reactive support surface. A commercially available capacitive pressure mapping system (XSENSOR, X3 Medical Seat System, Calgary, Canada) was used to evaluate a standard pediatric mattress and four commercially available pressure-redistributing support surfaces. The pressure mapping system was validated for use in the pediatric population through studies on sensitivity, accuracy, creep, and repeatability. Then, a pilot pressure mapping study on healthy children under 6 years old (n = 22) was performed to determine interface pressure and pressure distribution between the occipital region of the skull and each surface: standard mattress, gel, foam, air and fluidized. The sensor was adequate to measure pressure generated by pediatric occipital loading, with 0.5-9% error in accuracy in the 25-95 mmHg range. The air surface had the lowest mean interface pressure (p pressure index (PPI), defined as the peak pressure averaged over four sensels, (p pressure for mattress, foam, fluidized, gel, and air materials were 24.8 ± 4.42, 24.1 ± 1.89, 19.4 ± 3.25, 17.9 ± 3.10, and 14.2 ± 1.41 mmHg, respectively. The air surface also had the most homogenous pressure distribution, with the highest mean to PPI ratio (p surfaces (p surface was the most effective pressure-redistributing material for pediatric occipital pressure as it had the lowest interface pressure and a homogeneous pressure distribution. This implies effective envelopment of the bony prominence of the occiput and increasing contact area to decrease peak pressure points. Copyright © 2015 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  11. AN ANATOMICAL PERSPECTIVE OF HUMAN OCCIPITAL CONDYLES AND FORAMEN MAGNUM WITH NEUROSURGICAL CORRELATES

    OpenAIRE

    Gaurav; Divya; Abha

    2014-01-01

    AIMS: Knowledge of condylar anatomy helps the surgeon in making important decisions regarding extent and direction of condylar drilling and minimizing injury and retraction of neural structures. Important preoperative information includes length, width, axis/directions and overriding of occipital condyle in foramen magnum, relationships of condyles to foramen magnum and to hypoglossal canal. The antero-posterior and transverse diameters of foramen magnum and amount of over...

  12. The Effects of Occipitalization of the Atlas on Facial Skeletal Morphology.

    Science.gov (United States)

    1982-09-01

    occipital synchondroses, and decidu - ous dentition , without evidence of eruption of the first permanent molars, indicating that these skulls are 3-6 years...different fromt Controlling Office) IS. SECURITY CLASS. (of this report’ UNCLASS 15a. DECLASSIFICATION DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of... PERMANENT HOME ADDRESS: Morphology 13 Magnolia Court PREVIOUS DEGREES: Savoy, Illinois 61874 B.S. University of Illinois 1964 TOTAL NUMBER OF PAGES

  13. Long-term occipital nerve stimulation for drug-resistant chronic cluster headache.

    Science.gov (United States)

    Leone, Massimo; Proietti Cecchini, Alberto; Messina, Giuseppe; Franzini, Angelo

    2017-07-01

    Introduction Chronic cluster headache is rare and some of these patients become drug-resistant. Occipital nerve stimulation has been successfully employed in open studies to treat chronic drug-resistant cluster headache. Data from large group of occipital nerve stimulation-treated chronic cluster headache patients with long duration follow-up are advantageous. Patients and methods Efficacy of occipital nerve stimulation has been evaluated in an experimental monocentric open-label study including 35 chronic drug-resistant cluster headache patients (mean age 42 years; 30 men; mean illness duration: 6.7 years). The primary end-point was a reduction in number of daily attacks. Results After a median follow-up of 6.1 years (range 1.6-10.7), 20 (66.7%) patients were responders (≥50% reduction in headache number per day): 12 (40%) responders showed a stable condition characterized by sporadic attacks, five responders had a 60-80% reduction in headache number per day and in the remaining three responders chronic cluster headache was transformed in episodic cluster headache. Ten (33.3%) patients were non-responders; half of these have been responders for a long period (mean 14.6 months; range 2-48 months). Battery depletion (21 patients 70%) and electrode migration (six patients - 20%) were the most frequent adverse events. Conclusions Occipital nerve stimulation efficacy is confirmed in chronic drug-resistant cluster headaches even after an exceptional long-term follow-up. Tolerance can occur years after improvement.

  14. Evaluation of spheno-occipital synchondrosis: A review of literature and considerations from forensic anthropologic point of view

    Science.gov (United States)

    Krishan, Kewal; Kanchan, Tanuj

    2013-01-01

    Cranial sutures and synchondrosis have long been studied by forensic scientists, human anatomists, and anthropologists for estimation of age in different population groups. Observation of the closure of spheno-occipital synchondrosis has an important role to play in the estimation of age in the examination of unknown human remains when a skull is brought for examination. The present article reviews the studies conducted on the closure of spheno-occipital synchondrosis and presents a few valuable considerations that would be essential for carrying out research related to closure of spheno-occipital synchondrosis in humans. PMID:24255553

  15. Dissociation between Conceptual and Perceptual Implicit Memory: Evidence from Patients with Frontal and Occipital Lobe Lesions

    Science.gov (United States)

    Gong, Liang; Wang, JiHua; Yang, XuDong; Feng, Lei; Li, Xiu; Gu, Cui; Wang, MeiHong; Hu, JiaYun; Cheng, Huaidong

    2016-01-01

    The latest neuroimaging studies about implicit memory (IM) have revealed that different IM types may be processed by different parts of the brain. However, studies have rarely examined what subtypes of IM processes are affected in patients with various brain injuries. Twenty patients with frontal lobe injury, 25 patients with occipital lobe injury, and 29 healthy controls (HC) were recruited for the study. Two subtypes of IM were investigated by using structurally parallel perceptual (picture identification task) and conceptual (category exemplar generation task) IM tests in the three groups, as well as explicit memory (EM) tests. The results indicated that the priming of conceptual IM and EM tasks in patients with frontal lobe injury was poorer than that observed in HC, while perceptual IM was identical between the two groups. By contrast, the priming of perceptual IM in patients with occipital lobe injury was poorer than that in HC, whereas the priming of conceptual IM and EM was similar to that in HC. This double dissociation between perceptual and conceptual IM across the brain areas implies that occipital lobes may participate in perceptual IM, while frontal lobes may be involved in processing conceptual memory. PMID:26793093

  16. The Disruption of Geniculocalcarine Tract in Occipital Neoplasm: A Diffusion Tensor Imaging Study

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2016-01-01

    Full Text Available Aim. Investigate the disruption of geniculocalcarine tract (GCT in different occipital neoplasm by diffusion tensor imaging (DTI. Methods. Thirty-two subjects (44.1 ± 3.6 years who had single occipital neoplasm (9 gliomas, 6 meningiomas, and 17 metastatic tumors with ipsilateral GCT involved and thirty healthy subjects (39.2 ± 3.3 years underwent conventional sequences scanning and diffusion tensor imaging by a 1.5T MR scanner. The diffusion-sensitive gradient direction is 13. Compare the fractional anisotropy (FA and mean diffusivity (MD values of healthy GCT with the corresponding values of GCT in peritumoral edema area. Perform diffusion tensor tractography (DTT on GCT by the line propagation technique in all subjects. Results. The FA values of GCT in peritumoral edema area decreased (P=0.001 while the MD values increased (P=0.002 when compared with healthy subjects. There was no difference in the FA values across tumor types (P=0.114 while the MD values of GCT in the metastatic tumor group were higher than the other groups (P=0.001. GCTs were infiltrated in all the 9 gliomas cases, with displacement in 2 cases and disruption in 7 cases. GCTs were displaced in 6 meningiomas cases. GCTs were displaced in all the 7 metastatic cases, with disruption in 7 cases. Conclusions. DTI represents valid markers for evaluating GCT’s disruption in occipital neoplasm. The disruption of GCT varies according to the properties of neoplasm.

  17. Muscarinic cholinergic receptor subtypes in cerebral cortex of Fisher 344 rats: a light microscope autoradiography study of age-related changes.

    Science.gov (United States)

    Tayebati, Seyed Khosrow; Di Tullio, Maria Antonietta; Amenta, Francesco

    2006-02-01

    The density and localization of muscarinic cholinergic M1-M5 receptor subtypes was investigated in frontal and occipital cortex of male Fisher 344 rats aged 6 months (young-adult), 15 months (mature) and 22 months (senescent) by combined kinetic and equilibrium binding and light microscope autoradiography. In 6-month-old rats, the rank order density of muscarinic cholinergic receptor subtypes was M1>M2>M4>M3>M5 both in frontal and occipital cortex. A not homogeneous distribution of different receptor subtypes throughout cerebrocortical layers of frontal or occipital cortex was found. In frontal cortex silver grains corresponding to the M1 and M2 receptor subtypes were decreased in 15- and 22-month-old groups. The M3 receptor density was remarkably and moderately decreased in layers II/III and V, respectively, of rats aged 15 and 22 months. A reduced M4 receptor density was observed in layer I and to a lesser extent in layer V of mature and senescent rats, whereas no age-related changes of M5 receptor were found. In occipital cortex a diminution of M1 receptor was observed in layers II/III and V of mature and senescent rats. The M2 receptor expression decreased in layer I of 15- and 22-month-old senescent rats, whereas M3-M5 receptors were unchanged with exception of a slight decrease of the M4 receptor in layer IV and of M5 receptor in layers II/III. These findings indicate a different sensitivity to aging of muscarinic receptor subtypes located in various cerebrocortical layers. This may account for the difficulty in obtaining relevant results in manipulating cholinoceptors to counter age-related impairment of cholinergic system.

  18. Transcranial random-noise stimulation of visual cortex potentiates value-driven attentional capture.

    Science.gov (United States)

    van Koningsbruggen, Martijn G; Ficarella, Stefania C; Battelli, Lorella; Hickey, Clayton

    2016-09-01

    Reward feedback following visual search causes the visual characteristics of targets to become salient and attention-drawing, but little is known about the mechanisms underlying this value-driven capture effect. Here, we use transcranial random noise stimulation (tRNS) to demonstrate that such reward potentiation involves induced plasticity in visual cortex. Human participants completed a feature-search reward-learning task involving the selection of a red or green colored target presented among distractors of various color. Each correct trial garnered reward and the magnitude of reward was determined by the color of the target. Three groups completed this task: two groups received tRNS over either occipital or frontal cortex, and the third group received sham stimulation as a control. In a subsequent test phase of the experiment participants searched for a unique shape presented among colored distractors. During the test phase, no tRNS was applied and no reward was available. However, in some trials a single distractor had color matching that associated with reward during training. Search for the target was impacted by the presence of such reward-associated distractors in the occipital stimulation group, demonstrating that plasticity in visual cortex contributes to value-driven attentional capture. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Study of physiology of visual cortex activated by rotating grating with functional MRI

    International Nuclear Information System (INIS)

    Liang Ping; Shao Qing; Zhang Zhiqiang; Lu Guangming

    2004-01-01

    Objective: To research the physiology of visual cortex activated by rotating grating with functional-MRI (fMRI), and to identify the components of the activation. Methods: Functional MRI was performed in 9 healthy volunteers by using GRE-EPI sequences on a 1.5 T MR scanner. In the block designing, rotating grating, static grating, and luminance were plotted as task states, while static grating, luminance, and darkness were set as control states. The stimuli tasks included six steps. Imaging processing and statistical analysis was carried out off-line using SPM99 in single-subject method. Results: Some respective areas of visual cortex were activated by the various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe located at primary vision area was related to the stimuli of white luminance. Its average maximum points were at 13, -98, -2 and 11, -100, -41 The bilateral activations of Brodmann 19th area located at MT area were related to visual motion perception. Its average maximum points were at 46, -72, -2 and -44, -74, 0. The mild activation in the middle of occipital lobe was related to form perception. Its average maximum points were at -12, -98, -6 and -16, -96, -6. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception, and form perception. FMRI has potential as a tool for studying the basic physiology of visual cortex. (authors)

  20. Lateral occipitotemporal cortex (LOTC) activity is greatest while viewing dance compared to visualization and movement: learning and expertise effects.

    Science.gov (United States)

    Di Nota, Paula M; Levkov, Gabriella; Bar, Rachel; DeSouza, Joseph F X

    2016-07-01

    The lateral occipitotemporal cortex (LOTC) is comprised of subregions selectively activated by images of human bodies (extrastriate body area, EBA), objects (lateral occipital complex, LO), and motion (MT+). However, their role in motor imagery and movement processing is unclear, as are the influences of learning and expertise on its recruitment. The purpose of our study was to examine putative changes in LOTC activation during action processing following motor learning of novel choreography in professional ballet dancers. Subjects were scanned with functional magnetic resonance imaging up to four times over 34 weeks and performed four tasks: viewing and visualizing a newly learned ballet dance, visualizing a dance that was not being learned, and movement of the foot. EBA, LO, and MT+ were activated most while viewing dance compared to visualization and movement. Significant increases in activation were observed over time in left LO only during visualization of the unlearned dance, and all subregions were activated bilaterally during the viewing task after 34 weeks of performance, suggesting learning-induced plasticity. Finally, we provide novel evidence for modulation of EBA with dance experience during the motor task, with significant activation elicited in a comparison group of novice dancers only. These results provide a composite of LOTC activation during action processing of newly learned ballet choreography and movement of the foot. The role of these areas is confirmed as primarily subserving observation of complex sequences of whole-body movement, with new evidence for modification by experience and over the course of real world ballet learning.

  1. Mature teratoma in association with neural tube defect (occipital encephalocele): series of four cases and review of the literature.

    Science.gov (United States)

    Goyal, Nishant; Singh, Pankaj Kumar; Kakkar, Aanchal; Sharma, Meher Chand; Mahapatra, Ashok Kumar

    2012-01-01

    Both occipital encephalocele and teratomas are midline congenital malformations. Encephalocele is a form of neural tube defect in which there is a congenital defect of the cranium through which occurs a protrusion of brain matter or meninges, while teratoma is a tumor derived from all three germ layers. The association between occipital encephalocele and teratoma has not been reported to date. In the present study, the authors present a series of four such cases. Copyright © 2012 S. Karger AG, Basel.

  2. Uncovering a context-specific connectional fingerprint of human dorsal premotor cortex

    DEFF Research Database (Denmark)

    Moisa, Marius; Siebner, Hartwig R; Pohmann, Rolf

    2012-01-01

    Primate electrophysiological and lesion studies indicate a prominent role of the left dorsal premotor cortex (PMd) in action selection based on learned sensorimotor associations. Here we applied transcranial magnetic stimulation (TMS) to human left PMd at low or high intensity while right-handed ...

  3. Incidence of neuropathic pain after radiofrequency denervation of the third occipital nerve

    Directory of Open Access Journals (Sweden)

    Gazelka HM

    2014-04-01

    Full Text Available Halena M Gazelka, Sarah Knievel, William D Mauck, Susan M Moeschler, Matthew J Pingree, Richard H Rho, Tim J Lamer Division of Pain Medicine, Mayo Clinic, Rochester, MN, USA Abstract: The purpose of this study was to identify the incidence of neuropathic pain occurring after radiofrequency neurotomy of the third occipital nerve (TON. This study was conducted at a teaching hospital from January 1, 2008, to March 31, 2010. With institutional review board approval, Current Procedural Terminology codes were used to identify patients who received radiofrequency ablation (RFA of the nerves supplying the C2-3 facet joint and the TON. The C3 dorsal ramus provides innervation to the C2-3 facet joint and the suboccipital cutaneous region, and procedures that included ablation to this region were reviewed for complications. Postprocedural data were collected by reviewing follow-up appointment notes and telephone calls. Included were patients who had new neuropathic pain in the distribution of the TON after RFA. They described what they were feeling as burning, tingling, or numbness. All patients who presented with complaints had normal neurologic findings and no secondary cause for their symptoms. The included patient medical records were then reviewed for severity and duration of symptoms and the need for treatment with pain medication. Sixty-four patients underwent C2-3 RFA or TON RFA, and 12 patients were identified as experiencing ablation-induced third occipital neuralgia, an incidence rate of 19%. This finding suggests that patients undergoing RFA of the nerves supplying the C2-3 joint or TON are at risk for postprocedural third occipital neuralgia. This possibility may affect providing informed consent as well as anticipating and managing postprocedural pain. Keywords: cervical spine, neuralgia, neurotomy, ablation

  4. Incidence of neuropathic pain after radiofrequency denervation of the third occipital nerve.

    Science.gov (United States)

    Gazelka, Halena M; Knievel, Sarah; Mauck, William D; Moeschler, Susan M; Pingree, Matthew J; Rho, Richard H; Lamer, Tim J

    2014-01-01

    The purpose of this study was to identify the incidence of neuropathic pain occurring after radiofrequency neurotomy of the third occipital nerve (TON). This study was conducted at a teaching hospital from January 1, 2008, to March 31, 2010. With institutional review board approval, Current Procedural Terminology codes were used to identify patients who received radiofrequency ablation (RFA) of the nerves supplying the C2-3 facet joint and the TON. The C3 dorsal ramus provides innervation to the C2-3 facet joint and the suboccipital cutaneous region, and procedures that included ablation to this region were reviewed for complications. Postprocedural data were collected by reviewing follow-up appointment notes and telephone calls. Included were patients who had new neuropathic pain in the distribution of the TON after RFA. They described what they were feeling as burning, tingling, or numbness. All patients who presented with complaints had normal neurologic findings and no secondary cause for their symptoms. The included patient medical records were then reviewed for severity and duration of symptoms and the need for treatment with pain medication. Sixty-four patients underwent C2-3 RFA or TON RFA, and 12 patients were identified as experiencing ablation-induced third occipital neuralgia, an incidence rate of 19%. This finding suggests that patients undergoing RFA of the nerves supplying the C2-3 joint or TON are at risk for postprocedural third occipital neuralgia. This possibility may affect providing informed consent as well as anticipating and managing postprocedural pain.

  5. [Bilateral greater occipital nerve block for treatment of post-dural puncture headache after caesarean operations].

    Science.gov (United States)

    Uyar Türkyilmaz, Esra; Eryilmaz, Nuray Camgöz; Güzey, Nihan Aydin; Moraloğlu, Özlem

    2016-01-01

    Post-dural puncture headache (PDPH) is an important complication of neuroaxial anesthesia and more frequently noted in pregnant women. The pain is described as severe, disturbing and its location is usually fronto-occipital. The conservative treatment of PDPH consists of bed rest, fluid theraphy, analgesics and caffeine. Epidural blood patch is gold standard theraphy but it is an invasive method. The greater occipital nerve (GON) is formed of sensory fibers that originate in the C2 and C3 segments of the spinal cord and it is the main sensory nerve of the occipital region. GON blockage has been used for the treatment of many kinds of headache. The aim of this retrospective study is to present the results of PDPH treated with GON block over 1 year period in our institute. 16 patients who had been diagnosed to have PDPH, and performed GON block after caesarean operations were included in the study. GON blocks were performed as the first treatment directly after diagnose of the PDPH with levobupivacaine and dexamethasone. The mean VAS score of the patients was 8.75 (±0.93) before the block; 3.87 (±1.78) 10min after the block; 1.18 (±2.04) 2h after the block and 2.13 (±1.64) 24h after the block. No adverse effects were observed. Treatment of PDPH with GON block seems to be a minimal invasive, easy and effective method especially after caesarean operations. A GON block may be considered before the application of a blood patch. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  6. Blood supply to the human sternocleidomastoid muscle by the sternocleidomastoid branch of the occipital artery.

    Science.gov (United States)

    Fróes, L B; Castro De Tolosa, E M; Camargo, R D; Pompeu, E; Liberti, E A

    1999-01-01

    The contribution of the sternocleidomastoid branch of the occipital artery, superior arterial pedicle (SAP), to the irrigation of the sternocleidomastoid muscle (SCM) was evaluated in fresh human cadavers by injecting Neoprene-latex for minute dissection. From its insertion in the mastoid process of the temporal bone, the SCM was divided into six levels. The Neoprene-latex injected into the SAP reached the upper three levels in all SCMs studied, which corresponds to the middle part of the studied SCM. In 43.3% of the SCM, this branch reached level four and in 36.6%, it reached level five. Copyright 1999 Wiley-Liss, Inc.

  7. Spinal Fluid Collection Technique from the Atlanto-occipital Space in Pigs

    Directory of Open Access Journals (Sweden)

    Antonio D’Angelo

    2009-01-01

    Full Text Available Cerebrospinal fluid (CSF analysis has an important role in the diagnosis of neurologic diseases. A technique for collecting CSF from the atlanto-occipital space in 20 pigs (body mass 150-160 kg is described and the CSF values are reported. CSF was relatively easily collected from the cerebellomedullary space in all animals. The protein concentration and total cell count of CFS samples ranged from 20 to 32 mg/dl and from 2 to 15 cells/μl, respectively. Mononuclear cells were the predominant cellular type; a variable proportion of two different cell populations (monocytoid cells and lymphocytes was observed.

  8. Dopamine D2 receptors in the cerebral cortex: Distribution and pharmacological characterization with [3H]raclopride

    International Nuclear Information System (INIS)

    Lidow, M.S.; Goldman-Rakic, P.S.; Rakic, P.; Innis, R.B.

    1989-01-01

    An apparent involvement of dopamine in the regulation of cognitive functions and the recognition of a widespread dopaminergic innervation of the cortex have focused attention on the identity of cortical dopamine receptors. However, only the presence and distribution of dopamine D 1 receptors in the cortex have been well documented. Comparable information on cortical D 2 sites is lacking. The authors report here the results of binding studied in the cortex and neostriatum of rat and monkey using the D 2 selective antagonist [ 3 H]raclopride. In both structures [ 3 H]raclopride bound in a sodium-dependent and saturable manner to a single population of sites with pharmacological profiles of dopamine D 2 receptors. D 2 sites were present in all regions of the cortex, although their density was much lower than in the neostriatum. The density of these sites in both monkey and, to a lesser extent, rat cortex displayed a rostral-caudal gradient with highest concentrations in the prefrontal and lowest concentrations in the occipital cortex, corresponding to dopamine levels in these areas. Thus, the present study established the presence and widespread distribution of dopamine D 2 receptors in the cortex

  9. Value of analyzing deep gray matter and occipital lobe perfusion to differentiate dementia with Lewy bodies from Alzheimer's disease.

    Science.gov (United States)

    Shimizu, Soichiro; Hanyu, Haruo; Hirao, Kentaro; Sato, Tomohiko; Iwamoto, Toshihiko; Koizumi, Kiyoshi

    2008-12-01

    Dementia with Lewy bodies (DLB) is generally characterized by a decrease in regional cerebral blood flow (rCBF) in the occipital lobe. However, not all patients with DLB have this feature. We explored characteristics of rCBF pattern changes to improve the identification of DLB, in addition to occipital hypoperfusion. The study population comprised 30 patients with probable DLB and 49 patients with probable Alzheimer's disease (AD) who underwent single-photon emission computed tomography. The data were analyzed using Neurological Statistical Image Analysis Software (NEUROSTAT). We established a template of the region of interest (ROI) presenting the parietal lobe, posterior cingulate, striatum, thalamus, and occipital lobe on the standard brain atlas. We then compared the mean Z scores in each ROI between DLB and AD. Moreover, we investigated the value of analyzing relative rCBF changes in both the deep gray matter and occipital lobe in differentiating DLB from AD. The DLB group showed a significant relative rCBF increase in the bilateral striatum and thalamus, and a significant relative rCBF decrease in the bilateral occipital lobe when compared with the AD group. Receiver-operating characteristic analysis revealed that determining the hyperperfusion in the thalamus together with the hypoperfusion in the occipital lobe enabled a more accurate differentiation between DLB and AD than studying individual areas. Studying the relative increase of rCBF in the deep gray matter, and the relative decrease of that in the occipital lobe achieved a high differentiation between DLB and AD. This suggests that determining both an increase and a decrease in rCBF pattern may be important in differentiating between the two diseases.

  10. Where are inion and endinion? Variations of the exo- and endocranial morphology of the occipital bone during hominin evolution.

    Science.gov (United States)

    Balzeau, Antoine; Grimaud-Hervé, Dominique; Gilissen, Emmanuel

    2011-10-01

    The occipital bone is frequently investigated in paleoanthropological studies because it has several features that help to differentiate various fossil hominin species. Among these features is the separation between inion and endinion, which has been proposed to be an autapomorphic trait in (Asian) Homo erectus. Methodologies are developed here to quantify for the first time the location of these anatomical points, and to interpret their variation due to the complex interactions between exocranial and endocranial size and shape of the occipital and nuchal planes, as well as the occipital lobes and cerebellum. On the basis of our analysis, neither 'the separation between inion and endinion' nor 'endinion below inion' can be considered as an autapomorphic trait in H. erectus, since this feature is a condition shared by extant African great apes and fossil hominins. Moreover, our results show that the exo- and endocranial anatomy of the occipital bone differs between hominins (except Paranthropus boisei specimens and KNM-ER 1805) and great apes. For example, chimpanzees and bonobos are characterized by a very high position of inion and their occipital bone shows an antero-posterior compression. However, these features are partly correlated with their small size when compared with hominins. Asian H. erectus specimens have a thick occipital torus, but do not differ from other robust specimens, neither in this feature nor in the analysed exo- and endocranial proportions of the occipital bone. Finally, the apparent brain size reduction during the Late Pleistocene and variation between the sexes in anatomically modern humans (AMH) reflect that specimens with smaller brains have a relatively larger posterior height of the cerebellum. However, this trend is not the sole explanation for the 'vertical shift' of endinion above inion that appears occasionally and exclusively in AMH. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Left atrial volume index

    DEFF Research Database (Denmark)

    Poulsen, Mikael K; Dahl, Jordi S; Henriksen, Jan Erik

    2013-01-01

    To determine the prognostic importance of left atrial (LA) dilatation in patients with type 2 diabetes (T2DM) and no history of cardiovascular disease.......To determine the prognostic importance of left atrial (LA) dilatation in patients with type 2 diabetes (T2DM) and no history of cardiovascular disease....

  12. Rotatory Subluxation and Facet Deformity in the Atlanto-occipital Joint in Patients with Chronic Atlantoaxial Rotatory Fixation: Two Case Reports.

    Science.gov (United States)

    Kashii, Masafumi; Masuhara, Kenta; Kaito, Takashi; Iwasaki, Motoki

    2017-01-01

    The relationship between the morphometry of atlantoaxial joint and chronic atlantoaxial rotatory fixation (AARF) is well known, but disorders in the atlanto-occipital joint in chronic AARF are not fully elucidated. The authors report two rare cases of secondary deformities in the atlanto-occipital joint in chronic AARF. Two patients with chronic AARF were treated with closed manipulation, skull traction and halo-vest immobilization. Clinical outcomes and radiographs were reviewed retrospectively, focusing on pathological changes in the atlanto-occipital joint using multiplanar reconstruction computed tomography and three-dimensional computed tomography images. Case 1 (12-year-old girl) had rotatory subluxation with a superior facet deformity of the atlas in the atlanto-occipital joint before the initiation of treatment. After a series of conservative treatments, both atlantoaxial and atlanto-occipital rotatory fixation could not be reduced, and both the superior facet deformity of the atlas and osteoarthritic changes in the atlanto-occipital developed. She was monitored without surgery because the disorder progressed to the spontaneous fusion of the occipital bone to the axis. Case 2 (13-year-old boy) had rotatory subluxation without facet deformity of the atlas in the atlanto-occipital joint before the initiation of treatment. However, both the superior facet deformity of the atlas and osteoarthritic changes in the atlanto-occipital developed over time, and both atlantoaxial and atlanto-occipital rotatory fixation could not be reduced after a series of conservative treatments. He still had severe neck pain and severely restricted neck mobility and underwent spinal fusion. Atlanto-occipital rotatory subluxation and facet deformity in the atlanto-occipital joint may occur after prolonged AARF. It is necessary to pay attention to pathological changes not only in the atlantoaxial joint but also in the atlanto-occipital joint, when orthopedic surgeons treat patients

  13. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  14. A huge occipital osteoblastoma accompanied with aneurysmal bone cyst in the posterior cranial fossa.

    Science.gov (United States)

    Han, Xi; Dong, Yan; Sun, Kehua; Lu, Yicheng

    2008-03-01

    Osteoblastoma is an infrequent benign tumor and skull involvement is extremely rare. The occipital bone is much less frequently involved. We report an unusual case of a huge occipital osteoblastoma with aneurysmal bone cyst in the posterior cranial fossa of a 20-year-old young man. MRI scan and CT three-dimensional reconstruction revealed that the tumor (approximately 8.5 cm x 6 cm x 5 cm) occupied nearly half volume of the posterior cranial fossa. The cerebellum, the forth ventricle and brain stem were compressed remarkably and hydrocephalus was noted. The tumor mass was multiloculated cystic and highly vascular. Excessive bleeding occurred during operation and total removal was achieved. The patient was symptom-free and MRI scan revealed no evidence of recrudescence after a follow-up period of 18 months. Pathological examination revealed that the lesion was a benign osteoblastoma with secondary aneurysmal bone cyst (ABC). ABC constitutes a highly vascular lesion while complete surgical resection is often impeded by excessive intraoperative bleeding. Preoperative embolization may reduce the risk. Despite the benign nature of osteoblastoma, local recurrence after incomplete resection is not rare and malignant transformation during recurrence may occur even after adequate surgery. Our case confirms the findings of previous investigators that if osteoblastoma is removed completely, no recurrence is expected even without adjuvant irradiation and chemotherapy.

  15. Vertebral artery dissection complicating occipital injection of heparin for treatment of thoracic outlet syndrome.

    Science.gov (United States)

    Melinek, Judy; Hart, Amy P

    2012-03-01

    A 38-year-old woman with a 2-year history of chronic neck pain radiating down her right arm underwent radiological and neurological evaluations, which revealed no anatomical cause for her pain. She sought alternative therapies including intramuscular heparin injections. Following a right occipital injection of heparin, cyanocobalamin, and lidocaine, she had a sudden cardiorespiratory arrest and was successfully resuscitated, but did not regain consciousness.Computed tomography of the head and neck and subsequent autopsy revealed a right vertebral artery dissection, but at autopsy, no significant subarachnoid hemorrhage was noted at the base of the brain. This is the first case report where heparin (a potent anticoagulant) used in an occipital injection was documented to cause a vertebral artery dissection. It is also the first reported case where radiographically and histologically documented vertebral artery dissection did not present with overwhelming subarachnoid hemorrhage at the base of the brain. The subtle gross anatomical findings in this case highlight the importance of evaluating the cervical spinal cord in any case of sudden cardiorespiratory arrest following even apparently minor neck injury.

  16. Study on the primary visual cortex of visually impaired subjects by means of 123I-IMP SPECT and MRI

    International Nuclear Information System (INIS)

    Ishikawa, Nobuyoshi; Satou, Motohiro; Takeda, Tohoru; Itai, Yuji; Nishijo, Kazushi.

    1995-01-01

    We conducted a study of rCBF in the primary visual cortex of visually impaired subjects who have not been subjected to external stimulation for a long period, by means of 123 I-IMP SPECT and MRI. The four subjects had lost their sight due to brain tumors (n=2), glaucoma (n=1) and trauma (n=1). 123 I-IMP SPECT showed no differences between the visually impaired group and a visually sound control group on visual analysis as well as semiquantitative analysis. MRI of the visually impaired subjects showed no organic changes, such as atrophy, in the occipital cortex. In conclusion, visually impaired subjects have no decrease in rCBF and no anatomical changes in the primary visual cortex. (author)

  17. The Anterior Prefrontal Cortex and the Hippocampus Are Negatively Correlated during False Memories.

    Science.gov (United States)

    Jeye, Brittany M; Karanian, Jessica M; Slotnick, Scott D

    2017-01-23

    False memories commonly activate the anterior/dorsolateral prefrontal cortex (A/DLPFC) and the hippocampus. These regions are assumed to work in concert during false memories, which would predict a positive correlation between the magnitudes of activity in these regions across participants. However, the A/DLPFC may also inhibit the hippocampus, which would predict a negative correlation between the magnitudes of activity in these regions. In the present functional magnetic resonance imaging (fMRI) study, during encoding, participants viewed abstract shapes in the left or right visual field. During retrieval, participants classified each old shape as previously in the "left" or "right" visual field followed by an "unsure"-"sure"-"very sure" confidence rating. The contrast of left-hits and left-misses produced two activations in the hippocampus and three activations in the left A/DLPFC. For each participant, activity associated with false memories (right-"left"-"very sure" responses) from the two hippocampal regions was plotted as a function of activity in each A/DLPFC region. Across participants, for one region in the left anterior prefrontal cortex, there was a negative correlation between the magnitudes of activity in this region and the hippocampus. This suggests that the anterior prefrontal cortex might inhibit the hippocampus during false memories and that participants engage either the anterior prefrontal cortex or the hippocampus during false memories.

  18. Right prefrontal cortex transcranial direct current stimulation enhances multi-day savings in sensorimotor adaptation.

    Science.gov (United States)

    Seidler, Rachael D; Gluskin, Brittany S; Greeley, Brian

    2017-01-01

    We have previously reported that visuospatial working memory performance and magnitude of activation in the right dorsolateral prefrontal cortex predict the rate of visuomotor adaptation. Recent behavioral studies suggest that sensorimotor savings, or faster relearning on second exposure to a task, are due to recall of these early, strategic components of adaptation. In the present study we applied anodal transcranial direct current stimulation to right or left prefrontal cortex or left motor cortex. We found that all groups adapted dart throwing movements while wearing prism lenses at the same rate as subjects receiving sham stimulation on day 1 On test day 2, which was conducted a few days later, the right prefrontal and left motor cortex groups adapted faster than the sham group. Moreover, only the right prefrontal group exhibited greater savings, expressed as a greater difference between day 1 and day 2 errors, compared with sham stimulation. These findings support the hypothesis that the right prefrontal cortex contributes to sensorimotor adaptation and savings. We have previously reported that visuospatial working memory performance and magnitude of activation in the right dorsolateral prefrontal cortex predict the rate of manual visuomotor adaptation. Sensorimotor savings, or faster adaptation to a previously experienced perturbation, has been recently linked to cognitive processes. We show that facilitating the right prefrontal cortex with anodal transcranial direct current stimulation enhances sensorimotor savings compared with sham stimulation. Copyright © 2017 the American Physiological Society.

  19. Laser-Evoked Potentials in Fibromyalgia: The Influence of Greater Occipital Nerve Stimulation on Cerebral Pain Processing.

    Science.gov (United States)

    Plazier, Mark; Ost, Jan; Snijders, Erwin; Gilbers, Martijn; Vancamp, Tim; De Ridder, Dirk; Vanneste, Sven

    2015-07-01

    Fibromyalgia causes widespread musculo-skeletal pain in the four quadrants of the body. Greater occipital nerve stimulation has recently shown beneficial effects in fibromyalgia patients on pain, fatigue, and mood disorders. Laser-evoked potentials (LEPs) are used for research to understand the pathophysiological mechanisms of pain and to evaluate the effects of pain treatment. In fibromyalgia patients, LEPs tend to have a higher N2 amplitude, a tendency to shorter latencies, and patients have a lower pain threshold. Greater occipital nerve stimulation might exert a modulation of the medial pain pathways processing the affective motivational components of pain (unpleasantness) as well as the descending pain inhibitory pathways (reducing pain), both of which are contributing to the N2P2 peak. To test this hypothesis, the authors performed LEPs in a group of fibromyalgia patients with and without greater occipital nerve stimulation. Occipital nerve stimulation does not alter the amplitudes of the LEP recordings, although a significant difference in latencies can be seen. More specifically, latencies of the N2P2 increased in the condition after stimulation, and especially at the Pz electrode. Our results suggest Occipital Nerve Stimulation (ONS) induces a modification of the balance between antinociceptive pain inhibitory pathways and pain-provoking pathways. © 2015 International Neuromodulation Society.

  20. Repetition Enhancement of Amygdala and Visual Cortex Functional Connectivity Reflects Nonconscious Memory for Negative Visual Stimuli.

    Science.gov (United States)

    Kark, Sarah M; Slotnick, Scott D; Kensinger, Elizabeth A

    2016-12-01

    Most studies using a recognition memory paradigm examine the neural processes that support the ability to consciously recognize past events. However, there can also be nonconscious influences from the prior study episode that reflect repetition suppression effects-a reduction in the magnitude of activity for repeated presentations of stimuli-that are revealed by comparing neural activity associated with forgotten items to correctly rejected novel items. The present fMRI study examined the effect of emotional valence (positive vs. negative) on repetition suppression effects. Using a standard recognition memory task, 24 participants viewed line drawings of previously studied negative, positive, and neutral photos intermixed with novel line drawings. For each item, participants made an old-new recognition judgment and a sure-unsure confidence rating. Collapsed across valence, repetition suppression effects were found in ventral occipital-temporal cortex and frontal regions. Activity levels in the majority of these regions were not modulated by valence. However, repetition enhancement of the amygdala and ventral occipital-temporal cortex functional connectivity reflected nonconscious memory for negative items. In this study, valence had little effect on activation patterns but had a larger effect on functional connectivity patterns that were markers of nonconscious memory. Beyond memory and emotion, these findings are relevant to other cognitive and social neuroscientists that utilize fMRI repetition effects to investigate perception, attention, social cognition, and other forms of learning and memory.

  1. Left heart catheterization

    Science.gov (United States)

    Catheterization - left heart ... to help guide the catheters up into your heart and arteries. Dye (sometimes called "contrast") will be ... in the blood vessels that lead to your heart. The catheter is then moved through the aortic ...

  2. Three-dimensional computed tomography angiography of the galenic system for the occipital transtentorial approach

    International Nuclear Information System (INIS)

    Suzuki, Yasuhiro; Nakajima, Masateru; Ikeda, Hisato; Abe, Takumi

    2005-01-01

    The venous variations of the galenic system were evaluated using three-dimensional computed tomography angiography (3D-CTA) to assess the influence on the occipital transtentorial approach in 150 patients who underwent 3D-CTA as a routine screening examination for cerebrovascular diseases. The variations of the vein of Galen with its tributaries, the tentorial sinus, and the veins around the tentorium were evaluated in multiple intensity projections and stereoscopic images. The angle between the vein of Galen and the straight sinus was 67.1±31.9 deg (mean±SD). Observation of the pineal body from the direction of the approach tended to extend to the quadrigeminal bodies in acute angle cases, and to the third ventricle in obtuse angle cases. Bilateral internal cerebral veins (ICVs) joined in the anterior portion were associated with a long vein of Galen, or in the posterior portion with a short vein of Galen. The distance between the bilateral ICVs was 4.66±2.28 mm (mean±SD), and the shape of the space could be classified as spindle, parallel, hairpin, and round types. The basal vein could be classified into well-developed, hypoplastic, hardly recognized, and mimicking two basal veins because the tributary did not join but ran parallel to the basal vein. The drainage pathways lead to the anterior or posterior portion of the vein of Galen, the ICV, the tentorial sinus, and the superior petrosal sinus. The various types of the tentorial sinus and primitive tentorial sinus which might be sacrificed during section of the tentorium were confirmed. The inferior cerebral vein draining to the tentorial sinus could be seen. 3D-CTA could also demonstrate the presence, the course, and the drainage points of the internal occipital vein, the precentral cerebellar vein, the posterior pericallosal vein, and so on. 3D-CTA is useful to evaluate the variations of the venous system and the relationship with the tumor, and for preoperative simulation and intraoperative navigation of

  3. Representation of action in occipito-temporal cortex.

    Science.gov (United States)

    Wiggett, Alison J; Downing, Paul E

    2011-07-01

    A fundamental question for social cognitive neuroscience is how and where in the brain the identities and actions of others are represented. Here we present a replication and extension of a study by Kable and Chatterjee [Kable, J. W., & Chatterjee, A. Specificity of action representations in the lateral occipito-temporal cortex. Journal of Cognitive Neuroscience, 18, 1498-1517, 2006] examining the role of occipito-temporal cortex in these processes. We presented full-cue movies of actors performing whole-body actions and used fMRI to test for action- and identity-specific adaptation effects. We examined a series of functionally defined regions, including the extrastriate and fusiform body areas, the fusiform face area, the parahippocampal place area, the lateral occipital complex, the right posterior superior temporal sulcus, and motion-selective area hMT+. These regions were analyzed with both standard univariate measures as well as multivoxel pattern analyses. Additionally, we performed whole-brain tests for significant adaptation effects. We found significant action-specific adaptation in many areas, but no evidence for identity-specific adaptation. We argue that this finding could be explained by differences in the familiarity of the stimuli presented: The actions shown were familiar but the actors performing the actions were unfamiliar. However, in contrast to previous findings, we found that the action adaptation effect could not be conclusively tied to specific functionally defined regions. Instead, our results suggest that the adaptation to previously seen actions across identities is a widespread effect, evident across lateral and ventral occipito-temporal cortex.

  4. An effect of bilingualism on the auditory cortex

    OpenAIRE

    Ressel, Volker; Pallier, Christophe; Ventura Campos, Noelia; Díaz, Begoña; Roessler, Abeba; Ávila Rivera, César; Sebastián Gallés, Nuria

    2012-01-01

    Two studies (Golestani et al., 2007; Wong et al., 2008) have reported a positive correlation between the ability to perceive foreign speech sounds and the volume of Heschl's gyrus (HG), the structure that houses the auditory cortex. More precisely, participants with larger left Heschl's gyri learned consonantal or tonal contrasts faster than those with smaller HG. These studies leave open the question of the impact of experience on HG volumes. In the current research, we investigated the effe...

  5. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala...... and the striatal circuitry, areas involved in emotion and reward processing. The PFC, however, is able to modulate amygdala reactivity via a feedback loop to this area. A role for serotonin in adjusting for this circuitry of cognitive regulation of emotion has long been suggested based primarily on the positive...... pharmacological effect of elevating serotonin levels in anxiety regulation. Recent animal and human functional magnetic resonance studies have pointed to a specific involvement of the 5-hydroxytryptamine (5-HT)2A serotonin receptor in the PFC feedback regulatory projection onto the amygdala. This receptor...

  6. Word Recognition in Auditory Cortex

    Science.gov (United States)

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  7. Imaging sensory effects of occipital nerve stimulation: a new computer-based method in neuromodulation.

    Science.gov (United States)

    Göbel, Anna; Göbel, Carl H; Heinze, Axel; Heinze-Kuhn, Katja; Petersen, Inga; Meinecke, Christoph; Clasen, Svenja; Niederberger, Uwe; Rasche, Dirk; Mehdorn, Hubertus M; Göbel, Hartmut

    2015-01-01

    Within the last years, occipital nerve stimulation (ONS) has proven to be an important method in the treatment of severe therapy-resistant neurological pain disorders. The correspondence between lead placement as well as possible stimulation parameters and the resulting stimulation effects remains unclear. The method aims to directly relate the neuromodulatory mechanisms with the clinical treatment results, to achieve insight in the mode of action of neuromodulation, to identify the most effective stimulation sets and to optimize individual treatment effects. We describe a new computer-based imaging method for mapping the spatial, cognitive and affective sensory effects of ONS. The procedure allows a quantitative and qualitative analysis of the relationship between lead positioning, the stimulation settings as well as the sensory and clinical stimulation effects. A regular mapping of stimulation and sensory parameters allows a coordinated monitoring. The stimulation results can be reviewed and compared with regards to clinical effectiveness. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Bilateral occipital lobe infarction with altitudinal field loss following radiofrequency cardiac catheter ablation

    Directory of Open Access Journals (Sweden)

    Chen Celia S

    2010-03-01

    Full Text Available Abstract Background Bilateral stroke following radiofrequency catheter ablation is an unusual complication and may result in bilateral altitudinal visual field defects. Bilateral altitudinal visual field defects usually result from prechiasmal pathology causing damage to both retinas or optic nerves and rarely from bilateral symmetric damage to the post chiasmal visual pathways. Case presentation A 48-year-old man complained of visual disturbance on wakening following radiofrequency catheter ablation. The patient had a CHADS score of 1 pre-operatively and no complications were noted intra-operatively. Examination revealed a bilateral superior altitudinal defect and MRI of the brain showed multifocal areas of infarction predominantly involving the occipital lobes which correlated to with the visual deficits. Conclusion While the risk of thromboembolism and perioperative stroke during radiofrequency catheter ablation is small, it is not insignificant.

  9. A case report of prenatally detected achondrogenesis type Ⅱ with an occipital cephalocele

    Directory of Open Access Journals (Sweden)

    Behnaz Moradi

    2017-09-01

    Full Text Available Achondrogenesis is a very rare lethal skeletal disorder. Here we describe a case of prenatally diagnosed achondrogenesis type Ⅱ in a 28 year-old woman at (17+4 wk. She had history of 5 first trimester missed abortions. The couple is consanguineous. Ultrasonography showed extreme micromelia, short neck and trunk, large head and prominent abdomen. Delayed ossification in sacral bones was detected and ossification of pubic rami was poor. There were associated large cystic hygroma, anasarca and also high occipital cephalocele. Posterior fossa was normal. Mild hypothelorism, depressed nasal bridge, low set ear and mild retrognathia were identified too. Amniocentesis result was compatible with a normal female fetus. Post mortem whole body radiography confirmed the diagnosis. To our knowledge, this is the second case report with association of cephalocele and achondrogenesis type Ⅱ.

  10. Conceito anátomo-fisiológico do lobo occipital

    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

  11. A rare case of bifurcated lesser occipital nerve in the posterior triangle of the neck

    Directory of Open Access Journals (Sweden)

    Naveen Kumar

    2016-09-01

    Full Text Available The origin of the lesser occipital nerve (LON may vary, but variations in its pattern are rare. We report here a case of LON, bifurcated into superior and inferior roots in the posterior triangle of the neck. Bifurcation of the LON formed about 1.5 cm above the nerve point of the neck, near the posterior border of the sternocleidomastoid muscle. Both roots ascended obliquely upwards, and later united to form a single trunk in the upper part of the posterior triangle of the neck. It then entered the scalp where its distribution was normal. Since the cutaneous nerves of the cervical plexus are anesthetized for pain relief, as with cervicogenic headache, exceptional morphological variations of these nerves should be taken into consideration before any anesthetic procedures are performed in this region. [Arch Clin Exp Surg 2016; 5(3.000: 184-186

  12. Timing and rate of spheno-occipital synchondrosis closure and its relationship to puberty.

    Directory of Open Access Journals (Sweden)

    Anwar Alhazmi

    Full Text Available This study examines the relationship between spheno-occipital synchondrosis (SOS closure and puberty onset in a modern American population. It also investigates the timing and the rate of SOS closure in males and females.The sample includes cross-sectional and longitudinal 3D Cone Beam Computed Tomography (CBCT scans of 741 individuals (361 males and 380 females aged 6-20 years. Each CBCT scan is visualized in the mid-sagittal plane, and the spheno-occipital synchondrosis (SOS is scored as completely open, partially fused, mostly fused, and completely fused. The Menarche commencement is used as an indicator of puberty onset in females.Mean ages of open, partially-fused, mostly-fused, and completely fused SOS were 11.07, 12.95, 14.44, and 16.41 years in males, and 9.75, 11.67, 13.25, and 15.25 in females, respectively. The results show there is a significant association between the SOS closure stage and the commencement of menarche (Fisher's Exact Test p < 0.001. It was found that females had a higher SOS closure rate (38.60% per year than males at the age of 10 years. The closure rate in males appears slower than females at age 10, but it lasts a longer time, ranging between 22 and 26% per year from age 11 to 14 years.There is a significant relationship between puberty onset and SOS closure, suggesting its closure is at least partially affected by systemic, hormonal changes in the growing adolescent. Also, SOS closure occurs at a faster rate and at an earlier age in females compared to males.

  13. The presence of occipital hair in the pilonidal sinus cavity-a triple approach to proof.

    Science.gov (United States)

    Doll, Dietrich; Bosche, F; Hauser, A; Moersdorf, P; Sinicina, I; Grunwald, J; Reckel, F; Luedi, M M

    2018-05-01

    Hair in the pilonidal sinus is not growing within the sinus cavity, as hair follicles are not present there. Not few pilonidal patients do not have intergluteal hair, which is said to be the causative agent of folliculitis and pilonidal genesis. So, what is the real source of the hair forming the typical pilonidal hair nest? A trifold approach was used: First, axial hair strength testing of pilonidal hair and body hair harvested from head, lower back (glabella sacralis), and cranial third of intergluteal fold. Hair strength match was compared clinically. Second, comparative morphological examination by expert forensic biologist of hair from sinus and dorsal body hair. Third, statistical Bayesian classification of every single sinus hair based on its strength was done to determine the most probable region of origin. Using clinical hair strength comparison, in 13/20 patients, head hair is the stiffest hair, followed by intergluteal hair. Only in 6/20 patients, this is the case with hair from the glabella sacralis. According to comparative morphological comparison, a minimum of 5 of 13 hair nests with possible hair allocation examined contain hair from the occiput. In 5/18 nests, hair could not be determined to a specific location though. Statistical classification with correction for multiple testing shows that 2 nests have hair samples that are at least 100 times more probable to originate from head or lower back than from intergluteal fold. We saw our null hypothesis that "hair in the sinus cavity is from the intergluteal region" rejected by each of three different approaches. There is strong evidence that occipital hair is present regularly in pilonidal sinus nests. We should start thinking of occipital hair as an important hair source for the development of the pilonidal hair nest.

  14. Fifteen Minutes of Left Prefrontal Repetitive Transcranial Magnetic Stimulation Acutely Increases Thermal Pain Thresholds in Healthy Adults

    Directory of Open Access Journals (Sweden)

    Jeffrey J Borckardt

    2007-01-01

    Full Text Available BACKGROUND: Transcranial magnetic stimulation (TMS of the motor cortex appears to alter pain perception in healthy adults and in patients with chronic neuropathic pain. There is, however, emerging brain imaging evidence that the left prefrontal cortex is involved in pain inhibition in humans.

  15. Representational Similarity of Body Parts in Human Occipitotemporal Cortex.

    Science.gov (United States)

    Bracci, Stefania; Caramazza, Alfonso; Peelen, Marius V

    2015-09-23

    Regions in human lateral and ventral occipitotemporal cortices (OTC) respond selectively to pictures of the human body and its parts. What are the organizational principles underlying body part responses in these regions? Here we used representational similarity analysis (RSA) of fMRI data to test multiple possible organizational principles: shape similarity, physical proximity, cortical homunculus proximity, and semantic similarity. Participants viewed pictures of whole persons, chairs, and eight body parts (hands, arms, legs, feet, chests, waists, upper faces, and lower faces). The similarity of multivoxel activity patterns for all body part pairs was established in whole person-selective OTC regions. The resulting neural similarity matrices were then compared with similarity matrices capturing the hypothesized organizational principles. Results showed that the semantic similarity model best captured the neural similarity of body parts in lateral and ventral OTC, which followed an organization in three clusters: (1) body parts used as action effectors (hands, feet, arms, and legs), (2) noneffector body parts (chests and waists), and (3) face parts (upper and lower faces). Whole-brain RSA revealed, in addition to OTC, regions in parietal and frontal cortex in which neural similarity was related to semantic similarity. In contrast, neural similarity in occipital cortex was best predicted by shape similarity models. We suggest that the semantic organization of body parts in high-level visual cortex relates to the different functions associated with the three body part clusters, reflecting the unique processing and connectivity demands associated with the different types of information (e.g., action, social) different body parts (e.g., limbs, faces) convey. Significance statement: While the organization of body part representations in motor and somatosensory cortices has been well characterized, the principles underlying body part representations in visual cortex

  16. Proprioceptive neuromuscular facilitation increases alpha absolute power in the dorsolateral prefrontal cortex and superior parietal cortex.

    Science.gov (United States)

    Lial, Lysnara; Moreira, Rayele; Correia, Luan; Andrade, Alzira; Pereira, Ane Caroline; Lira, Ricardo; Figueiredo, Rogério; Silva-Júnior, Fernando; Orsini, Marco; Ribeiro, Pedro; Velasques, Bruna; Cagy, Maurício; Teixeira, Silmar; Bastos, Victor Hugo

    2017-09-01

    The physiotherapist's clinical practice includes proprioceptive neuromuscular facilitation (PNF), which is a treatment concept that accelerates the response of neuromuscular mechanisms through spiral and diagonal movements. The adaptations that occur in the nervous system following PNF are still poorly described in the literature. Thus, this study had a goal to investigate the electrophysiological changes in the fronto-parietal circuit during PNF and movement in sagittal and diagonal patterns. This study included 30 female participants, who were divided into three groups (control, PNF, and flexion groups). Electroencephalogram measurements were determined before and after tasks were performed by each group. For the statistical analysis, a two-way ANOVA was performed for the factors group and time. Interactions between the two factors were investigated using a one-way ANOVA. A value of p < 0.004 was considered significant. The results showed an increase in alpha absolute power in the left dorsolateral prefrontal cortex and upper left parietal cortex of the PNF group, suggesting these areas work together to execute a motor action. The PNF group showed a greater alpha absolute power compared with the other groups, indicating a specific cortical demand for planning and attention, reinforcing its use for the rehabilitation of individuals.

  17. The changes of regional cerebral blood flow: successful pain relief of intractable CRPS type II patients by motor cortex stimulation

    International Nuclear Information System (INIS)

    Jung, J. A.; Son, H. S.; Kim, S. H.; Jung, S. G

    2004-01-01

    Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control

  18. The effects of left and right monocular viewing on hemispheric activation.

    Science.gov (United States)

    Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

    2018-03-01

    Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

  19. [Recurrent left atrial myxoma].

    Science.gov (United States)

    Moreno Martínez, Francisco L; Lagomasino Hidalgo, Alvaro; Mirabal Rodríguez, Roger; López Bermúdez, Félix H; López Bernal, Omaida J

    2003-01-01

    Primary cardiac tumors are rare. Mixomas are the most common among them; 75% are located in the left atrium, 20% in the right atrium, and the rest in the ventricles. The seldom appear in atrio-ventricular valves. Recidivant mixoma are also rare, appearing in 1-5% of all patients that have undergone surgical treatment of a mixoma. In this paper we present our experience with a female patient, who 8 years after having been operated of a left atrial mixoma, began with symptoms of mild heart failure. Transthoracic echocardiography revealed recurrence of the tumor, and was therefore subjected to a second open-heart surgery from which she recovered without complications.

  20. Surgical Treatment for Occipital Condyle Fracture, C1 Dislocation, and Cerebellar Contusion with Hemorrhage after Blunt Head Trauma

    Directory of Open Access Journals (Sweden)

    Shigeo Ueda

    2016-01-01

    Full Text Available Occipital condyle fractures (OCFs have been treated as rare traumatic injuries, but the number of reported OCFs has gradually increased because of the popularization of computed tomography (CT and magnetic resonance imaging (MRI. The patient in this report presented with OCFs and C1 dislocation, along with traumatic cerebellar hemorrhage, which led to craniovertebral junction instability. This case was also an extremely rare clinical condition in which the patient presented with traumatic lower cranial nerve palsy secondary to OCFs. When the patient was transferred to our hospital, the occipital bone remained defective extensively due to surgical treatment of cerebellar hemorrhage. For this reason, concurrent cranioplasty was performed with resin in order to fix the occipital bone plate strongly. The resin-made occipital bone was used to secure a titanium plate and screws enabled us to perform posterior fusion of the craniovertebral junction. Although the patient wore a halo vest for 3 months after surgery, lower cranial nerve symptoms, including not only neck pain but also paralysis of the throat and larynx, improved postoperatively. No complications were detected during outpatient follow-up, which continued for 5 years postoperatively.

  1. Variations in the squamous part of the occipital bone in medieval and contemporary cranial series from Bulgaria.

    Science.gov (United States)

    Nikolova, S; Toneva, D; Yordanov, Y; Lazarov, N

    2014-11-01

    The squamous part of the occipital bone is a place of many different variations. They are a result of faulty ossification in the occipital squama or due to the presence of sutural bones in the lambda region. As their differentiation is intricate because of the various criteria used, the issue of their recognition in the adult skull still remains difficult even though they can be clearly distinguished at a younger age. The aim of the present study was to compare the frequency of interparietal, preinterparietal and sutural bones in the lambda region in medieval male and female cranial series as well as between medieval and contemporary male series from Bulgaria. We also discuss the development of the occipital squama in order to set clearer criteria for further differentiation of such variations in the adult skull. In the reviewed 3 cranial series, the variations in the squamous portion of the occipital bone were observed with a low frequency. The incidence of preinterparietal bones was more common than the interparietal ones. The sutural bones in the lambda region were numerous in the series. No statistically significant sex or intergroup differences were established. So even if these anatomical variations are relatively rare, the understanding of them is of significance for many disciplines like anthropology, comparative and developmental anatomy, clinical and forensic medicine.

  2. Walk-related mimic word activates the extrastriate visual cortex in the human brain: an fMRI study.

    Science.gov (United States)

    Osaka, Naoyuki

    2009-03-02

    I present an fMRI study demonstrating that a mimic word highly suggestive of human walking, heard by the ear with eyes closed, significantly activates the visual cortex located in extrastriate occipital region (BA19, 18) and superior temporal sulcus (STS) while hearing non-sense words that do not imply walk under the same task does not activate these areas in humans. I concluded that BA19 and 18 would be a critical region for generating visual images of walking and related intentional stance, respectively, evoked by an onomatopoeia word that implied walking.

  3. The left fusiform gyrus hosts trisensory representations of manipulable objects

    DEFF Research Database (Denmark)

    Kassuba, Tanja; Klinge, Corinna; Hölig, Cordula

    2011-01-01

    During object manipulation the brain integrates the visual, auditory, and haptic experience of an object into a unified percept. Previous brain imaging studies have implicated for instance the dorsal part of the lateral occipital complex in visuo-tactile and the posterior superior temporal sulcus....... In the first experiment, we identified brain regions which were consistently activated by unimodal visual, auditory, and haptic processing of manipulable objects relative to non-object control stimuli presented in the same modality. In the second experiment, we assessed regional brain activations when...... participants had to match object-related information that was presented simultaneously in two or all three modalities. Only a well-defined region in left fusiform gyrus (FG) showed an object-specific activation during unisensory processing in the visual, auditory, and tactile modalities. The same region...

  4. False memory for context and true memory for context similarly activate the parahippocampal cortex.

    Science.gov (United States)

    Karanian, Jessica M; Slotnick, Scott D

    2017-06-01

    The role of the parahippocampal cortex is currently a topic of debate. One view posits that the parahippocampal cortex specifically processes spatial layouts and sensory details (i.e., the visual-spatial processing view). In contrast, the other view posits that the parahippocampal cortex more generally processes spatial and non-spatial contexts (i.e., the general contextual processing view). A large number of studies have found that true memories activate the parahippocampal cortex to a greater degree than false memories, which would appear to support the visual-spatial processing view as true memories are typically associated with greater visual-spatial detail than false memories. However, in previous studies, contextual details were also greater for true memories than false memories. Thus, such differential activity in the parahippocampal cortex may have reflected differences in contextual processing, which would challenge the visual-spatial processing view. In the present functional magnetic resonance imaging (fMRI) study, we employed a source memory paradigm to investigate the functional role of the parahippocampal cortex during true memory and false memory for contextual information to distinguish between the visual-spatial processing view and the general contextual processing view. During encoding, abstract shapes were presented to the left or right of fixation. During retrieval, old shapes were presented at fixation and participants indicated whether each shape was previously on the "left" or "right" followed by an "unsure", "sure", or "very sure" confidence rating. The conjunction of confident true memories for context and confident false memories for context produced activity in the parahippocampal cortex, which indicates that this region is associated with contextual processing. Furthermore, the direct contrast of true memory and false memory produced activity in the visual cortex but did not produce activity in the parahippocampal cortex. The present

  5. Greater occipital nerve stimulation via the Bion microstimulator: implantation technique and stimulation parameters. Clinical trial: NCT00205894.

    Science.gov (United States)

    Trentman, Terrence L; Rosenfeld, David M; Vargas, Bert B; Schwedt, Todd J; Zimmerman, Richard S; Dodick, David W

    2009-01-01

    Millions of patients suffer from medically refractory and disabling primary headache disorders. This problem has led to a search for new and innovative treatment modalities, including neuromodulation of the occipital nerves. The primary aim of this study is to describe an implantation technique for the Bion microstimulator and document stimulation parameters and stimulation maps after Bion placement adjacent to the greater occipital nerve. The secondary aim is to document outcome measures one year post-implant. Prospective, observational feasibility study. Nine patients with medically refractory primary headache disorders participated in this study. Approximately 6 months after Bion insertion, stimulation parameters and maps were documented for all patients. At one year, outcome measures were collected including the Migraine Disability Assessment Score. At 6 months, the mean perception threshold was 0.47 mA, while the mean discomfort threshold was 6.8 mA (stimulation range 0.47-6.8 mA). The mean paresthesia threshold was 1.64 mA and the mean usage range was 16.0. There were no major complications reported such as device migration, infection, or erosion. One patient stopped using her Bion before the 12-month follow-up visit. At one year, 7 of the 8 patients were judged as having obtained fair or better results in terms of reduction of disability; 5 patients had greater than a 90% reduction in disability. Small, heterogeneous patient population without control group. Not blinded or randomized. The Bion can be successfully inserted adjacent to the greater occipital nerve in an effort to treat refractory primary headache disorders. This microstimulator may provide effective occipital stimulation and headache control while minimizing the risks associated with percutaneous or paddle leads implanted subcutaneously in the occipital region.

  6. Visual cortex in aging and Alzheimer's disease: changes in visual field maps and population receptive fields

    Science.gov (United States)

    Brewer, Alyssa A.; Barton, Brian

    2012-01-01

    Although several studies have suggested that cortical alterations underlie such age-related visual deficits as decreased acuity, little is known about what changes actually occur in visual cortex during healthy aging. Two recent studies showed changes in primary visual cortex (V1) during normal aging; however, no studies have characterized the effects of aging on visual cortex beyond V1, important measurements both for understanding the aging process and for comparison to changes in age-related diseases. Similarly, there is almost no information about changes in visual cortex in Alzheimer's disease (AD), the most common form of dementia. Because visual deficits are often reported as one of the first symptoms of AD, measurements of such changes in the visual cortex of AD patients might improve our understanding of how the visual system is affected by neurodegeneration as well as aid early detection, accurate diagnosis and timely treatment of AD. Here we use fMRI to first compare the visual field map (VFM) organization and population receptive fields (pRFs) between young adults and healthy aging subjects for occipital VFMs V1, V2, V3, and hV4. Healthy aging subjects do not show major VFM organizational deficits, but do have reduced surface area and increased pRF sizes in the foveal representations of V1, V2, and hV4 relative to healthy young control subjects. These measurements are consistent with behavioral deficits seen in healthy aging. We then demonstrate the feasibility and first characterization of these measurements in two patients with mild AD, which reveal potential changes in visual cortex as part of the pathophysiology of AD. Our data aid in our understanding of the changes in the visual processing pathways in normal aging and provide the foundation for future research into earlier and more definitive detection of AD. PMID:24570669

  7. Left atrial appendage occlusion

    Directory of Open Access Journals (Sweden)

    Ahmad Mirdamadi

    2013-01-01

    Full Text Available Left atrial appendage (LAA occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC, it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC and mitral valve replacement (MVR too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

  8. The human dorsal premotor cortex facilitates the excitability of ipsilateral primary motor cortex via a short latency cortico-cortical route

    DEFF Research Database (Denmark)

    Groppa, Sergiu; Schlaak, Boris H; Münchau, Alexander

    2012-01-01

    In non-human primates, invasive tracing and electrostimulation studies have identified strong ipsilateral cortico-cortical connections between dorsal premotor- (PMd) and the primary motor cortex (M1(HAND) ). Here, we applied dual-site transcranial magnetic stimulation (dsTMS) to left PMd and M1(H...

  9. Maps of the Auditory Cortex.

    Science.gov (United States)

    Brewer, Alyssa A; Barton, Brian

    2016-07-08

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.

  10. Hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Thiagarajan Ravi

    2007-05-01

    Full Text Available Abstract Hypoplastic left heart syndrome(HLHS refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch. Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision

  11. Chemosensory Learning in the Cortex

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2011-09-01

    Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

  12. The Anterior Prefrontal Cortex and the Hippocampus Are Negatively Correlated during False Memories

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    Brittany M. Jeye

    2017-01-01

    Full Text Available False memories commonly activate the anterior/dorsolateral prefrontal cortex (A/DLPFC and the hippocampus. These regions are assumed to work in concert during false memories, which would predict a positive correlation between the magnitudes of activity in these regions across participants. However, the A/DLPFC may also inhibit the hippocampus, which would predict a negative correlation between the magnitudes of activity in these regions. In the present functional magnetic resonance imaging (fMRI study, during encoding, participants viewed abstract shapes in the left or right visual field. During retrieval, participants classified each old shape as previously in the “left” or “right” visual field followed by an “unsure”–“sure”–“very sure” confidence rating. The contrast of left-hits and left-misses produced two activations in the hippocampus and three activations in the left A/DLPFC. For each participant, activity associated with false memories (right–“left”–“very sure” responses from the two hippocampal regions was plotted as a function of activity in each A/DLPFC region. Across participants, for one region in the left anterior prefrontal cortex, there was a negative correlation between the magnitudes of activity in this region and the hippocampus. This suggests that the anterior prefrontal cortex might inhibit the hippocampus during false memories and that participants engage either the anterior prefrontal cortex or the hippocampus during false memories.

  13. Frontopolar cortex mediates abstract integration in analogy.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Kraemer, David J M; Shamosh, Noah A; Dunbar, Kevin N

    2006-06-22

    Integration of abstractly similar relations during analogical reasoning was investigated using functional magnetic resonance imaging. Activation elicited by an analogical reasoning task that required both complex working memory and integration of abstractly similar relations was compared to activation elicited by a non-analogical task that required complex working memory in the absence of abstract relational integration. A left-sided region of the frontal pole of the brain (BA 9/10) was selectively active for the abstract relational integration component of analogical reasoning. Analogical reasoning also engaged a left-sided network of parieto-frontal regions. Activity in this network during analogical reasoning is hypothesized to reflect categorical alignment of individual component terms that make up analogies. This parieto-frontal network was also engaged by the complex control task, which involved explicit categorization, but not by a simpler control task, which did not involve categorization. We hypothesize that frontopolar cortex mediates abstract relational integration in complex reasoning while parieto-frontal regions mediate working memory processes, including manipulation of terms for the purpose of categorical alignment, that facilitate this integration.

  14. Greater occipital nerve block for the acute treatment of prolonged or persistent migraine aura.

    Science.gov (United States)

    Cuadrado, María L; Aledo-Serrano, Ángel; López-Ruiz, Pedro; Gutiérrez-Viedma, Álvaro; Fernández, Cristina; Orviz, Aida; Arias, José A

    2017-07-01

    Background Presently, there is no evidence to guide the acute treatment of migraine aura. We aimed to describe the effect of greater occipital nerve (GON) anaesthetic block as a symptomatic treatment for long-lasting (prolonged or persistent) migraine aura. Methods Patients who presented with migraine aura lasting > 2 hours were consecutively recruited during one year at the Headache Unit and the Emergency Department of a tertiary hospital. All patients underwent a bilateral GON block with bupivacaine 0.5%. Patients were followed up for 24 hours. Results A total of 22 auras were treated in 18 patients. Auras consisted of visual ( n = 13), visual and sensory ( n = 4) or sensory symptoms alone ( n = 5). Eleven episodes met diagnostic criteria for persistent aura (>1 week) without infarction. The response was complete without early recurrence in 11 cases (50%), complete with recurrence in auras lasting auras (72.7% vs. 27.3%; p = 0.033). Conclusions GON block could be an effective symptomatic treatment for prolonged or persistent migraine aura. Randomised controlled trials are still required to confirm these results.

  15. Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

    Science.gov (United States)

    Zhang, Ying; Whitfield-Gabrieli, Susan; Christodoulou, Joanna A.; Gabrieli, John D. E.

    2013-01-01

    Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading. PMID:23825653

  16. Benign occipital epilepsy of childhood: Panayiotopoulos syndrome in a 3 year old child

    Directory of Open Access Journals (Sweden)

    Menon Narayanankutty Sunilkumar , Vadakut Krishnan Parvathy

    2014-11-01

    Full Text Available Panayiotopoulos syndrome (PS is a relatively frequent and benign epileptic syndrome seen in children in the age group of 3-6 years and is characterised by predominantly autonomic symptoms and/or simple motor focal seizures followed or not by impairment of consciousness. Although multifocal spikes with high amplitude sharp-slow wave complexes at various locations can be present in the EEG, interictal electroencephalogram (EEG in children with this particular type of epilepsy characteristically shows occipital spikes. This syndrome has known to be a masquerader and can imitate gastroenteritis, encephalitis, syncope, migraine, sleep disorders or metabolic diseases. In the absence of thorough knowledge of types of benign epilepsy syndromes and their various clinical presentations, epilepsy such as PS can be easily missed. The peculiar aspects of this type of epilepsy in children should be known not only by paediatricians but also by general doctors because a correct diagnosis would avoid aggressive interventions and concerns on account of its benign outcome. In this case study, we report a case of PS in a 3 year old child.

  17. Greater occipital nerve infiltration under MR guidance. Feasibility study and preliminary results

    International Nuclear Information System (INIS)

    Kastler, Adrian; Perolat, Romain; Kastler, Bruno; Maindet-Dominici, Caroline; Fritz, Jan; Benabid, Alim Louis; Chabardes, Stephan; Krainik, Alexandre

    2018-01-01

    To assess the feasibility of greater occipital nerve (GON) intermediate site infiltration with MRI guidance. Eleven consecutive patients suffering from chronic refractory cranio-facial pain who underwent 16 GON infiltrations were included in this prospective study. All of the procedures were performed on an outpatient basis in the research facility of our institution, with a 1.5 T scanner. The fatty space between inferior obliquus and semispinalis muscles at C1-C2 level was defined as the target. Technical success was defined as the ability to accurately inject the products at the target, assessed by post-procedure axial and sagittal proton density-weighted sequences. Clinical success was defined as a 50% pain decrease at 1 month. Technical success was 100%. GON was depicted in 6/11 cases on planning MRI sequences. Mean duration of procedure was 22.5 min (range 16-41). Clinical success was obtained in 7/11 included patients (63.6%) with a mean self-reported improvement of 78%. Interventional MR-guidance for GON infiltration is a feasible technique offering similar results to an already established effective procedure. It may appear as a useful tool in specific populations, such as young patients and repeat infiltrations, and should be considered in these settings. (orig.)

  18. The occipital face area is causally involved in the formation of identity-specific face representations.

    Science.gov (United States)

    Ambrus, Géza Gergely; Dotzer, Maria; Schweinberger, Stefan R; Kovács, Gyula

    2017-12-01

    Transcranial magnetic stimulation (TMS) and neuroimaging studies suggest a role of the right occipital face area (rOFA) in early facial feature processing. However, the degree to which rOFA is necessary for the encoding of facial identity has been less clear. Here we used a state-dependent TMS paradigm, where stimulation preferentially facilitates attributes encoded by less active neural populations, to investigate the role of the rOFA in face perception and specifically in image-independent identity processing. Participants performed a familiarity decision task for famous and unknown target faces, preceded by brief (200 ms) or longer (3500 ms) exposures to primes which were either an image of a different identity (DiffID), another image of the same identity (SameID), the same image (SameIMG), or a Fourier-randomized noise pattern (NOISE) while either the rOFA or the vertex as control was stimulated by single-pulse TMS. Strikingly, TMS to the rOFA eliminated the advantage of SameID over DiffID condition, thereby disrupting identity-specific priming, while leaving image-specific priming (better performance for SameIMG vs. SameID) unaffected. Our results suggest that the role of rOFA is not limited to low-level feature processing, and emphasize its role in image-independent facial identity processing and the formation of identity-specific memory traces.

  19. Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    Full Text Available Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI to examine brain activation while adults with or without dyslexia responded to the change of an arrow's direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.

  20. Category-selective attention modulates unconscious processes in the middle occipital gyrus.

    Science.gov (United States)

    Tu, Shen; Qiu, Jiang; Martens, Ulla; Zhang, Qinglin

    2013-06-01

    Many studies have revealed the top-down modulation (spatial attention, attentional load, etc.) on unconscious processing. However, there is little research about how category-selective attention could modulate the unconscious processing. In the present study, using functional magnetic resonance imaging (fMRI), the results showed that category-selective attention modulated unconscious face/tool processing in the middle occipital gyrus (MOG). Interestingly, MOG effects were of opposed direction for face and tool processes. During unconscious face processing, activation in MOG decreased under the face-selective attention compared with tool-selective attention. This result was in line with the predictive coding theory. During unconscious tool processing, however, activation in MOG increased under the tool-selective attention compared with face-selective attention. The different effects might be ascribed to an interaction between top-down category-selective processes and bottom-up processes in the partial awareness level as proposed by Kouider, De Gardelle, Sackur, and Dupoux (2010). Specifically, we suppose an "excessive activation" hypothesis. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Childhood Epilepsy with Occipital Paroxysm: Classification, Atypical Evolution and Long-Term Prognosis in 35 Patients.

    Science.gov (United States)

    Aksoy, Ayşe; Haliloğlu, Göknur; Yalnızoğlu, Dilek; Turanlı, Güzide

    2015-01-01

    We studied childhood epilepsy with occipital paroxysms (CEOP) with regard to typical and/or atypical ictal symptoms, EEG findings, as well as atypical evolution and outcome. This report focuses on the main clinical and EEG features of CEOP underlying its atypical symptoms and its management. Thirty-five patients with CEOP were subdivided into Panayiotopoulos syndrome (n=15), Gastaut syndrome (n=11), and mixed type (n=9). Nine patients (25%) with CEOP (mixed type) had shown atypical ictal manifestations and presented combinations of vomiting (100%) along with visual symptoms (66%), and/or eye deviation (66%), and headaches (44%). Five patients with CEOP had atypical evolution. However, the dictate for strict delineation into either the early-onset or late-onset forms of CEOP should be discarded because many children will present mixed clinical findings at varying ages. We think a detailed evaluation should be carried out as to why certain patients who apply have atypical findings, and whether each patient has age related evolution or not.

  2. Experienced mindfulness meditators exhibit higher parietal-occipital EEG gamma activity during NREM sleep.

    Directory of Open Access Journals (Sweden)

    Fabio Ferrarelli

    Full Text Available Over the past several years meditation practice has gained increasing attention as a non-pharmacological intervention to provide health related benefits, from promoting general wellness to alleviating the symptoms of a variety of medical conditions. However, the effects of meditation training on brain activity still need to be fully characterized. Sleep provides a unique approach to explore the meditation-related plastic changes in brain function. In this study we performed sleep high-density electroencephalographic (hdEEG recordings in long-term meditators (LTM of Buddhist meditation practices (approximately 8700 mean hours of life practice and meditation naive individuals. We found that LTM had increased parietal-occipital EEG gamma power during NREM sleep. This increase was specific for the gamma range (25-40 Hz, was not related to the level of spontaneous arousal during NREM and was positively correlated with the length of lifetime daily meditation practice. Altogether, these findings indicate that meditation practice produces measurable changes in spontaneous brain activity, and suggest that EEG gamma activity during sleep represents a sensitive measure of the long-lasting, plastic effects of meditative training on brain function.

  3. Experienced Mindfulness Meditators Exhibit Higher Parietal-Occipital EEG Gamma Activity during NREM Sleep

    Science.gov (United States)

    Ferrarelli, Fabio; Smith, Richard; Dentico, Daniela; Riedner, Brady A.; Zennig, Corinna; Benca, Ruth M.; Lutz, Antoine; Davidson, Richard J.; Tononi, Giulio

    2013-01-01

    Over the past several years meditation practice has gained increasing attention as a non-pharmacological intervention to provide health related benefits, from promoting general wellness to alleviating the symptoms of a variety of medical conditions. However, the effects of meditation training on brain activity still need to be fully characterized. Sleep provides a unique approach to explore the meditation-related plastic changes in brain function. In this study we performed sleep high-density electroencephalographic (hdEEG) recordings in long-term meditators (LTM) of Buddhist meditation practices (approximately 8700 mean hours of life practice) and meditation naive individuals. We found that LTM had increased parietal-occipital EEG gamma power during NREM sleep. This increase was specific for the gamma range (25–40 Hz), was not related to the level of spontaneous arousal during NREM and was positively correlated with the length of lifetime daily meditation practice. Altogether, these findings indicate that meditation practice produces measurable changes in spontaneous brain activity, and suggest that EEG gamma activity during sleep represents a sensitive measure of the long-lasting, plastic effects of meditative training on brain function. PMID:24015304

  4. First-drug treatment failures in 42 Turkish children with idiopathic childhood occipital epilepsies.

    Science.gov (United States)

    Incecik, Faruk; Herguner, Ozlem M; Altunbasak, Sakir

    2015-01-01

    The early and late benign occipital epilepsies of childhood (BOEC) are described as two discrete electro-clinical syndromes, eponymously known as Panayiotopoulos and Gastaut syndromes. The purpose of this study was to identify predictors of failure to respond to the initial antiepileptic drug (AED). A total of 42 children with BOEC were enrolled. Predictive factors were analyzed by survival methods. Among the 42, 25 patients (59.5%) were boys and 17 (40.5%) were girls and the mean age at the seizure onset was 7.46 ± 2.65 years (4-14 years). Of the 42 patients, 34 (81.0%) were treated relatively successfully with the first AED treatment, and 8 (19.0%) were not responded initial AED treatment. There was no correlation between response to initial AED treatment and sex, consanguinity, epilepsy history of family, age of seizure onset, frequency of seizures, history of status epilepticus, duration of starting first treatment, findings on electroencephalogram. However, history of febrile seizure and type of BOEC were significantly associated with failure risk. Factors predicting failure to respond to the AED were history of febrile seizure and type of BOEC in children with BOEC.

  5. Chronic motor cortex stimulation in patients with advanced Parkinson's disease and effects on striatal dopaminergic transmission as assessed by 123I-FP-CIT SPECT: a preliminary report.

    Science.gov (United States)

    Di Giuda, Daniela; Calcagni, Maria L; Totaro, Manuela; Cocciolillo, Fabrizio; Piano, Carla; Soleti, Francesco; Fasano, Alfonso; Cioni, Beatrice; Bentivoglio, Anna R; Giordano, Alessandro

    2012-09-01

    The objective of this study was to assess striatal dopamine transporter availability in patients with advanced Parkinson's disease (PD) before and after 13 months of unilateral extradural motor cortex stimulation (EMCS) with [123I]N-ω-fluoropropyl-2-β-carbo-methoxy-3-β-(4-iodophenyl)nortropane single photon emission computed tomography (123I-FP-CIT SPECT). Six PD patients (five women and one man, aged 63.2 ± 5.6 years) underwent 123I-FP-CIT SPECT and clinical evaluation [Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Quality of Life Scale (PDQL)] preoperatively, 8 and 13 months after EMCS. Striatum-to-occipital cortex, caudate-to-occipital cortex and putamen-to-occipital cortex 123I-FP-CIT uptake ratios were calculated using the region of interest method. Total and part III UPDRS scores significantly decreased at 8 and 13 months after stimulation (P=0.02 and 0.04, respectively); UPDRS part II and PDQL scores improved after 13 months (P=0.02 and 0.04, respectively). No significant differences in 123I-FP-CIT uptake ratios between baseline and follow-up were found in the examined regions. However, a progressive reduction in 123I-FP-CIT uptake ratios in the striatum contralateral to the implant was found. In contrast, no further decrease in 123I-FP-CIT uptake ratios was detected in the striatum ipsilateral to the implant. There were no correlations between changes in 123I-FP-CIT uptake ratios with disease duration, changes in medication dosage and motor UPDRS scores. Despite a small but highly selected sample of advanced PD patients, our results showed that no further dopamine transporter reduction occurred in the striatum ipsilateral to the implant side. This finding could lead to the hypothesis that EMCS might elicit a 'neuroprotective' effect, as suggested by significant clinical benefits.

  6. Structural and functional changes in the somatosensory cortex in euthymic females with bipolar disorder.

    Science.gov (United States)

    Minuzzi, Luciano; Syan, Sabrina K; Smith, Mara; Hall, Alexander; Hall, Geoffrey Bc; Frey, Benicio N

    2017-12-01

    Current evidence from neuroimaging data suggests possible dysfunction of the fronto-striatal-limbic circuits in individuals with bipolar disorder. Somatosensory cortical function has been implicated in emotional recognition, risk-taking and affective responses through sensory modalities. This study investigates anatomy and function of the somatosensory cortex in euthymic bipolar women. In total, 68 right-handed euthymic women (bipolar disorder = 32 and healthy controls = 36) between 16 and 45 years of age underwent high-resolution anatomical and functional magnetic resonance imaging during the mid-follicular menstrual phase. The somatosensory cortex was used as a seed region for resting-state functional connectivity analysis. Voxel-based morphometry was used to evaluate somatosensory cortical gray matter volume between groups. We found increased resting-state functional connectivity between the somatosensory cortex and insular cortex, inferior prefrontal gyrus and frontal orbital cortex in euthymic bipolar disorder subjects compared to healthy controls. Voxel-based morphometry analysis showed decreased gray matter in the left somatosensory cortex in the bipolar disorder group. Whole-brain voxel-based morphometry analysis controlled by age did not reveal any additional significant difference between groups. This study is the first to date to evaluate anatomy and function of the somatosensory cortex in a well-characterized sample of euthymic bipolar disorder females. Anatomical and functional changes in the somatosensory cortex in this population might contribute to the pathophysiology of bipolar disorder.

  7. Ventrolateral and dorsomedial frontal cortex lesions impair mnemonic context retrieval.

    Science.gov (United States)

    Chapados, Catherine; Petrides, Michael

    2015-02-22

    The prefrontal cortex appears to contribute to the mnemonic retrieval of the context within which stimuli are experienced, but only under certain conditions that remain to be clarified. Patients with lesions to the frontal cortex, the temporal lobe and neurologically intact individuals were tested for context memory retrieval when verbal stimuli (words) had been experienced across multiple (unstable context condition) or unique (stable context condition) contexts; basic recognition memory of these words-in-contexts was also tested. Patients with lesions to the right ventrolateral prefrontal cortex (VLPFC) were impaired on context retrieval only when the words had been seen in multiple contexts, demonstrating that this prefrontal region is critical for active retrieval processing necessary to disambiguate memory items embedded across multiple contexts. Patients with lesions to the left dorsomedial prefrontal region were impaired on both context retrieval conditions, regardless of the stability of the stimulus-to-context associations. Conversely, prefrontal lesions sparing the ventrolateral and dorsomedial regions did not impair context retrieval. Only patients with temporal lobe excisions were impaired on basic recognition memory. The results demonstrate a basic contribution of the left dorsomedial frontal region to mnemonic context retrieval, with the VLPFC engaged, selectively, when contextual relations are unstable and require disambiguation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  8. Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Khuansiri Narajeenron

    2017-04-01

    Full Text Available Audience: The audience for this classic team-based learning (cTBL session is emergency medicine residents, faculty, and students; although this topic is applicable to internal medicine and family medicine residents. Introduction: A left ventricular assist device (LVAD is a mechanical circulatory support device that can be placed in critically-ill patients who have poor left ventricular function. After LVAD implantation, patients have improved quality of life.1 The number of LVAD patients worldwide continues to rise. Left-ventricular assist device patients may present to the emergency department (ED with severe, life-threatening conditions. It is essential that emergency physicians have a good understanding of LVADs and their complications. Objectives: Upon completion of this cTBL module, the learner will be able to: 1 Properly assess LVAD patients’ circulatory status; 2 appropriately resuscitate LVAD patients; 3 identify common LVAD complications; 4 evaluate and appropriately manage patients with LVAD malfunctions. Method: The method for this didactic session is cTBL.

  9. Feature-coding transitions to conjunction-coding with progression through human visual cortex.

    Science.gov (United States)

    Cowell, Rosemary A; Leger, Krystal R; Serences, John T

    2017-12-01

    Identifying an object and distinguishing it from similar items depends upon the ability to perceive its component parts as conjoined into a cohesive whole, but the brain mechanisms underlying this ability remain elusive. The ventral visual processing pathway in primates is organized hierarchically: Neuronal responses in early stages are sensitive to the manipulation of simple visual features, whereas neuronal responses in subsequent stages are tuned to increasingly complex stimulus attributes. It is widely assumed that feature-coding dominates in early visual cortex whereas later visual regions employ conjunction-coding in which object representations are different from the sum of their simple feature parts. However, no study in humans has demonstrated that putative object-level codes in higher visual cortex cannot be accounted for by feature-coding and that putative feature codes in regions prior to ventral temporal cortex are not equally well characterized as object-level codes. Thus the existence of a transition from feature- to conjunction-coding in human visual cortex remains unconfirmed, and if a transition does occur its location remains unknown. By employing multivariate analysis of functional imaging data, we measure both feature-coding and conjunction-coding directly, using the same set of visual stimuli, and pit them against each other to reveal the relative dominance of one vs. the other throughout cortex. Our results reveal a transition from feature-coding in early visual cortex to conjunction-coding in both inferior temporal and posterior parietal cortices. This novel method enables the use of experimentally controlled stimulus features to investigate population-level feature and conjunction codes throughout human cortex. NEW & NOTEWORTHY We use a novel analysis of neuroimaging data to assess representations throughout visual cortex, revealing a transition from feature-coding to conjunction-coding along both ventral and dorsal pathways. Occipital

  10. Functional sex differences in human primary auditory cortex

    International Nuclear Information System (INIS)

    Ruytjens, Liesbet; Georgiadis, Janniko R.; Holstege, Gert; Wit, Hero P.; Albers, Frans W.J.; Willemsen, Antoon T.M.

    2007-01-01

    We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

  11. Functional sex differences in human primary auditory cortex.

    Science.gov (United States)

    Ruytjens, Liesbet; Georgiadis, Janniko R; Holstege, Gert; Wit, Hero P; Albers, Frans W J; Willemsen, Antoon T M

    2007-12-01

    We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies.

  12. Thickening of the somatosensory cortex in migraine without aura.

    Science.gov (United States)

    Kim, Ji Hyun; Kim, Jung Bin; Suh, Sang-il; Seo, Woo-Keun; Oh, Kyungmi; Koh, Seong-Beom

    2014-12-01

    We aimed to explore cortical thickness abnormalities in a homogeneous group of patients with migraine without aura and to delineate possible relationships between cortical thickness changes and clinical variables. Fifty-six female migraine patients without aura and T2-visible white matter hyperintensities and 34 female controls were scanned on a 3T magnetic resonance imager. Cortical thickness was estimated and compared between patients and controls using a whole-brain vertex-by-vertex analysis. Correlation analysis was conducted between cortical thickness of significant clusters and clinical variables. Compared to controls, migraine patients had cortical thickening in left rostral middle frontal gyrus and bilateral post-central gyri. Region-of-interest analysis revealed cortical thickening of bilateral post-central gyri in migraine patients relative to controls. The average thickness of bilateral post-central gyri positively correlated with disease duration as well as estimated lifetime headache frequency. We have provided evidence for interictal cortical abnormalities of thickened prefrontal cortex and somatosensory cortex in female migraine patients without aura. Our findings of greater thickening of the somatosensory cortex in relation to increasing disease duration and increasing headache frequency suggest that repeated migraine attacks over time may lead to structural changes of the somatosensory cortex through increased noxious afferent input within the trigemino-thalamo-cortical pathway in migraine. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. Functional sex differences in human primary auditory cortex

    Energy Technology Data Exchange (ETDEWEB)

    Ruytjens, Liesbet [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Georgiadis, Janniko R. [University of Groningen, University Medical Center Groningen, Department of Anatomy and Embryology, Groningen (Netherlands); Holstege, Gert [University of Groningen, University Medical Center Groningen, Center for Uroneurology, Groningen (Netherlands); Wit, Hero P. [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); Albers, Frans W.J. [University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Willemsen, Antoon T.M. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands)

    2007-12-15

    We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

  14. Definição do limite anterolateral do lobo occipital em peças anatômicas e exames de imagem

    Directory of Open Access Journals (Sweden)

    Gusmão Sebastião

    2002-01-01

    Full Text Available Com o objetivo de definir o limite anterolateral do lobo occipital foram estudados sete segmentos cefálicos de cadáveres humanos, 103 exames de tomografia computadorizada e 104 exames de ressonância magnética do encéfalo considerados normais. Foram encontradas uma prega da dura-máter sobre o seio transverso (plica tentorial pré-occipital e uma protuberância óssea relacionadas diretamente com a incisura pré-occipital. Foi calculada, também, a distância média entre o sulco parieto-occipital e a sutura lambdóide. Nos exames de imagem, especialmente na ressonância magnética, foi possível identificar a incisura pré-occipital e/ou a protuberância na parede craniana relacionada a ela, bem como o sulco parieto-occipital e a sutura lambdóide, referências que permitem a definição do limite anterolateral do lobo occipital.

  15. Correlation of neuropsychological and metabolic changes after epilepsy surgery in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis.

    Science.gov (United States)

    Güvenç, Canan; Dupont, Patrick; Van den Stock, Jan; Seynaeve, Laura; Porke, Kathleen; Dries, Eva; Van Bouwel, Karen; van Loon, Johannes; Theys, Tom; Goffin, Karolien E; Van Paesschen, Wim

    2018-04-12

    Epilepsy surgery often causes changes in cognition and cerebral glucose metabolism. Our aim was to explore relationships between pre- and postoperative cerebral metabolism as measured with 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) and neuropsychological test scores in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), who were rendered seizure-free after epilepsy surgery. Thirteen patients were included. All had neuropsychological testing and an interictal FDG-PET scan of the brain pre- and postoperative. Correlations between changes in neuropsychological test scores and metabolism were examined using statistical parametric mapping (SPM). There were no significant changes in the neuropsychological test scores pre- and postoperatively at the group level. Decreased metabolism was observed in the left mesial temporal regions and occipital lobe. Increased metabolism was observed in the bi-frontal and right parietal lobes, temporal lobes, occipital lobes, thalamus, cerebellum, and vermis. In these regions, we did not find a correlation between changes in metabolism and neuropsychological test scores. A significant negative correlation, however, was found between metabolic changes in the precuneus and Boston Naming Test (BNT) scores. There are significant metabolic decreases in the left mesial temporal regions and increases in the bi-frontal lobes; right parietal, temporal, and occipital lobes; right thalamus; cerebellum; and vermis in patients with left MTLE-HS who were rendered seizure-free after epilepsy surgery. We could not confirm that these changes translate into significant cognitive changes. A significant negative correlation was found between changes in confrontation naming and changes in metabolism in the precuneus. We speculate that the precuneus may play a compensatory role in patients with postoperative naming difficulties after left TLE surgery. Understanding of these neural mechanisms may aid in

  16. Aphasia following left thalamic hemorrhage. A study by Western Aphasia Battery and single photon emission CT

    Energy Technology Data Exchange (ETDEWEB)

    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro

    1984-07-01

    A report is given of 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months) in which language disorders were examined by Western Aphasia Battery (WAB) and cerebral blood flow was measured 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 the left temporooccipital region and low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, emission CT showed slight low flow area at the temporo-occipital region similar to the case with transcortical sensory aphasia. In another case with anomic aphasia there was a 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. In all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus.

  17. Parieto-occipital hypoperfusion in late whiplash syndrome: first quantitative SPET study using technetium-99m bicisate (ECD)

    International Nuclear Information System (INIS)

    Otte, A.; Ettlin, T.; Fierz, L.; Mueller-Brand, J.

    1996-01-01

    Brain single-photon emission tomography (SPET) with N,N''-1,2-ethylene-diylbis-L-cysteine diethyl ester dihydrochloride (ECD) was performed on ten patients with a clinically high grade late whiplash syndrome and on 11 controls. Two independent readers blinded to the clinical diagnosis were able to separate the ten patients from normal controls. All these patients had qualitative bilateral parieto-occipital hypoperfusion. To confirm this, the perfusion rate of parieto-occipital over global (perfusion index) was calculated after drawing elliptical regions of interest in transversal-oblique slices. The perfusion indices in patients were significantly lower than in controls as tested by the Mann-Whitney U test. This quantitative study proves our recent qualitatively analysed observation. (orig./MG)

  18. Thinning of the lateral prefrontal cortex during adolescence predicts emotion regulation in females.

    Science.gov (United States)

    Vijayakumar, Nandita; Whittle, Sarah; Yücel, Murat; Dennison, Meg; Simmons, Julian; Allen, Nicholas B

    2014-11-01

    Adolescence is a crucial period for the development of adaptive emotion regulation strategies. Despite the fact that structural maturation of the prefrontal cortex during adolescence is often assumed to underlie the maturation of emotion regulation strategies, no longitudinal studies have directly assessed this relationship. This study examined whether use of cognitive reappraisal strategies during late adolescence was predicted by (i) absolute prefrontal cortical thickness during early adolescence and (ii) structural maturation of the prefrontal cortex between early and mid-adolescence. Ninety-two adolescents underwent baseline and follow-up magnetic resonance imaging scans when they were aged approximately 12 and 16 years, respectively. FreeSurfer software was used to obtain cortical thickness estimates for three prefrontal regions [anterior cingulate cortex; dorsolateral prefrontal cortex (dlPFC); ventrolateral prefrontal cortex (vlPFC)]. The Emotion Regulation Questionnaire was completed when adolescents were aged approximately 19 years. Results showed that greater cortical thinning of the left dlPFC and left vlPFC during adolescence was significantly associated with greater use of cognitive reappraisal in females, though no such relationship was evident in males. Furthermore, baseline left dlPFC thickness predicted cognitive reappraisal at trend level. These findings suggest that cortical maturation may play a role in the development of adaptive emotion regulation strategies during adolescence. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Geometry of the articular facets of the lateral atlanto-axial joints in the case of occipitalization.

    Science.gov (United States)

    Ryniewicz, A M; Skrzat, J; Ryniewicz, A; Ryniewicz, W; Walocha, J

    2010-08-01

    This study investigates if atlanto-occipital fusion affects the size and geometrical configuration of the articular facets of the atlanto-axial joint. Morphometric analysis was performed on the male adult skull, the occipital bone of which is assimilated with the first cervical vertebrae (the atlas). The perimeter, Feret's diameter, surface area, and circularity of the inferior articular fa-cets were measured. However, we did not observe significant bilateral differences in size of the inferior articular facets of the assimilated atlas compared to normal first cervical vertebrae. Geometrical conformation of the articular facets of the atlas and axis was assessed using a coordinate measuring machine (PMM - 12106, Leitz). The results obtained from this machine indicated that the inferior articular facets of the assimilated atlas presented asymmetrical orientation compared to the normal anatomy of the atlas. Hence, in the case of occipitalization, the gap between the articulating facets of the atlas and the axis was measured to be greater than in the normal atlanto-axial joint. Computer assisted tomography was applied to visualise the anatomical relationship between the inferior articular facets of the assimilated atlas and the corresponding facets located on the axis. In this case, radiographic examination revealed that the bilaterally articulating facets (inferior and superior) showed disproportion in their adjustment within the lateral atlanto-axial joints. Thus, we concluded that the fusion of the atlas with the occipital bone altered the geometry of the inferior articular facets of the atlas and influenced the orientation of the superior articular facets of the axis.

  20. An adult case of the developmental apraxia, agnosia, Gerstmann's syndrome with bilateral parieto-temporo-occipital lesions in brain CT

    International Nuclear Information System (INIS)

    Suzuki, Toshihito; Shiraishi, Hiroyasu; Koizumi, Junzo; Ichikawa, Tadahiko; Hayakawa, Tatsuo.

    1986-01-01

    A 36-year-old woman with a history of cerebral meningitis had various neuropsychological disorders, such as Gerstmann's syndrome, developmental apraxia and agnosia and difficulty in reading, in addition to moderate mental retardation and epileptoid. Cranial CT showed bilateral low-density areas with temporo-parieto-occipital extension. It seems that these lesions result from meningitis and are responsible for the occurrence of neuropsychological disorders. (Namekawa, K.)

  1. Eye muscle proprioception is represented bilaterally in the sensorimotor cortex

    DEFF Research Database (Denmark)

    Balslev, Daniela; Albert, Neil B; Miall, Chris

    2011-01-01

    for either eye contrasts with the contralateral representation of hand proprioception. We suggest that the proprioceptive representation of the two eyes next to each other in either somatosensory cortex and extending into the premotor cortex reflects the integrative nature of the eye position sense, which...... eye after a virtual lesion with rTMS over the left somatosensory area. However, it is possible that the proprioceptive representation of the EOM extends to other brain sites, which were not examined in these previous studies. The aim of this fMRI study was to sample the whole brain to identify...... touch alone. For either eye, the brain area commonly activated by passive and active eye movement was located bilaterally in the somatosensory area extending into the motor and premotor cytoarchitectonic areas. We suggest this is where EOM proprioception is processed. The bilateral representation...

  2. Atividade epileptiforms occipital com ou sem bloqueio pela abertura dos olhos: estudo comparativo clínico-eletrencefalográfico Occipital epileptiform activity with or without blocking by eyes opening: a comparative clinical and electroencephalographic study

    Directory of Open Access Journals (Sweden)

    Lineu Corrêa Fonseca

    1995-12-01

    Full Text Available Atividade epileptiforme occipital bloqueada pela abertura dos olhos (AEOB foi descrita por Gastaut como elemento constitutivo do quadro da epilepsia idiopática parcial da infância com paroxismos occipitais. Estudamos comparativamente 20 pacientes com AEOB e 120 casos com atividade epileptiforme occipital não bloqueada pela abertura dos olhos (AEO. Houve tendência ao aparecimento mais precoce de AEO (predomínio até os 7 anos de idade do que AEOB e ao início mais frequente das crises antes dos 4 anos de idade no grupo AEO do que em AEOB. Não houve diferença significativa entre os grupos AEOB e AEO quanto ao relato de epilepsia (70,0% e 61,6%, respectivamente e evidências de lesões do sistema nervoso central. Convulsões febris, isoladamente, foram apenas relatadas no grupo AEO (11,6%. Atraso no desenvolvimento neuropsicomotor foi relatado apenas no grupo AEO (22,5% dos casos. Complexos ponta-onda foram registrados com maior frequência no grupo AEOB (80,0% do que em AEO (17.5%. Nossos dados sugerem diferenças no contexto clínico e eletrencefalográfico entre os grupos com AEO e AEOB.Occipital epileptiform activity blocked by eyes opening (OEAB is primarily observed in childhood epilepsy with occipital paroxysms but may be also found in cases of benign childhood epilepsy with centrotemporal spikes, cryptogenic/symptomatic partial epilepsies, idiopathic generalized epilepsies and in patients with no seizures. We studied comparatively EEG and clinical features of 20 patients with OEAB and 120 patients with occipital epileptiform activity not suppressed by eyes opening (OEA. Epileptiform activity (OEA or OEAB was registered until the 7 years of age in 67.5% of the patients with OEA and in 45% of the patients with OEAB. Epileptic seizures began before 4 years of age in 44.4% of the cases with OEA and in 14.2% in the group OEAB. Febrile convulsions alone occurred only in the OEA group (12.5%. Developmental retardation was referred in 27

  3. Dyslexic children lack word selectivity gradients in occipito-temporal and inferior frontal cortex

    Directory of Open Access Journals (Sweden)

    O.A. Olulade

    2015-01-01

    Full Text Available fMRI studies using a region-of-interest approach have revealed that the ventral portion of the left occipito-temporal cortex, which is specialized for orthographic processing of visually presented words (and includes the so-called “visual word form area”, VWFA, is characterized by a posterior-to-anterior gradient of increasing selectivity for words in typically reading adults, adolescents, and children (e.g. Brem et al., 2006, 2009. Similarly, the left inferior frontal cortex (IFC has been shown to exhibit a medial-to-lateral gradient of print selectivity in typically reading adults (Vinckier et al., 2007. Functional brain imaging studies of dyslexia have reported relative underactivity in left hemisphere occipito-temporal and inferior frontal regions using whole-brain analyses during word processing tasks. Hence, the question arises whether gradient sensitivities in these regions are altered in dyslexia. Indeed, a region-of-interest analysis revealed the gradient-specific functional specialization in the occipito-temporal cortex to be disrupted in dyslexic children (van der Mark et al., 2009. Building on these studies, we here (1 investigate if a word-selective gradient exists in the inferior frontal cortex in addition to the occipito-temporal cortex in normally reading children, (2 compare typically reading with dyslexic children, and (3 examine functional connections between these regions in both groups. We replicated the previously reported anterior-to-posterior gradient of increasing selectivity for words in the left occipito-temporal cortex in typically reading children, and its absence in the dyslexic children. Our novel finding is the detection of a pattern of increasing selectivity for words along the medial-to-lateral axis of the left inferior frontal cortex in typically reading children and evidence of functional connectivity between the most lateral aspect of this area and the anterior aspects of the occipito-temporal cortex. We

  4. Widespread heterogeneous neuronal loss across the cerebral cortex in Huntington's disease.

    Science.gov (United States)

    Nana, Alissa L; Kim, Eric H; Thu, Doris C V; Oorschot, Dorothy E; Tippett, Lynette J; Hogg, Virginia M; Synek, Beth J; Roxburgh, Richard; Waldvogel, Henry J; Faull, Richard L M

    2014-01-01

    Huntington's disease is an autosomal dominant neurodegenerative disease characterized by neuronal degeneration in the basal ganglia and cerebral cortex, and a variable symptom profile. Although progressive striatal degeneration is known to occur and is related to symptom profile, little is known about the cellular basis of symptom heterogeneity across the entire cerebral cortex. To investigate this, we have undertaken a double blind study using unbiased stereological cell counting techniques to determine the pattern of cell loss in six representative cortical regions from the frontal, parietal, temporal, and occipital lobes in the brains of 14 Huntington's disease cases and 15 controls. The results clearly demonstrate a widespread loss of total neurons and pyramidal cells across all cortical regions studied, except for the primary visual cortex. Importantly, the results show that cell loss is remarkably variable both within and between Huntington's disease cases. The results also show that neuronal loss in the primary sensory and secondary visual cortices relate to Huntington's disease motor symptom profiles, and neuronal loss across the associational cortices in the frontal, parietal and temporal lobes is related to both Huntington's disease motor and to mood symptom profiles. This finding considerably extends a previous study (Thu et al., Brain, 2010; 133:1094-1110) which showed that neuronal loss in the primary motor cortex was related specifically to the motor symptom profiles while neuronal loss in the anterior cingulate cortex was related specifically to mood symptom profiles. The extent of cortical cell loss in the current study was generally related to the striatal neuropathological grade, but not to CAG repeat length on the HTT gene. Overall our findings show that Huntington's disease is characterized by a heterogeneous pattern of neuronal cell loss across the entire cerebrum which varies with symptom profile.

  5. Left Ventricular Pseudoaneurysm Perceived as a Left Lung Mass

    Directory of Open Access Journals (Sweden)

    Ugur Gocen

    2013-02-01

    Full Text Available Left ventricular pseudo-aneurysm is a rare complication of aneurysmectomy. We present a case of surgically-treated left ventricular pseudo-aneurysm which was diagnosed three years after coronary artery bypass grafting and left ventricular aneurysmectomy. The presenting symptoms, diagnostic evaluation and surgical repair are described. [Cukurova Med J 2013; 38(1.000: 123-125

  6. Occipital foramina development involves localised regulation of mesenchyme proliferation and is independent of apoptosis

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    Akbareian, Sophia E; Pitsillides, Andrew A; Macharia, Raymond G; McGonnell, Imelda M

    2015-01-01

    Cranial foramina are holes within the skull, formed during development, allowing entry and exit of blood vessels and nerves. Once formed they must remain open, due to the vital structures they contain, i.e. optic nerves, jugular vein, carotid artery, and other cranial nerves and blood vessels. Understanding cranial foramina development is essential as cranial malformations lead to the stenosis or complete closure of these structures, resulting in blindness, deafness, facial paralysis, raised intracranial pressure and lethality. Here we focus on describing early events in the formation of the jugular, carotid and hypoglossal cranial foramina that form in the mesoderm-derived, endochondral occipital bones at the base of the embryonic chick skull. Whole-mount skeletal staining of skulls indicates the appearance of these foramina from HH32/D7.5 onwards. Haematoxylin & eosin staining of sections shows that the intimately associated mesenchyme, neighbouring the contents of these cranial foramina, is initially very dense and gradually becomes sparser as development proceeds. Histological examination also revealed that these foramina initially contain relatively large-diameter nerves, which later become refined, and are closely associated with the blood vessel, which they also innervate within the confines of the foramina. Interestingly cranial foramina in the base of the skull contain blood vessels lacking smooth muscle actin, which suggests these blood vessels belong to glomus body structures within the foramina. The blood vessel shape also appears to dictate the overall shape of the resulting foramina. We initially hypothesised that cranial foramina development could involve targeted proliferation and local apoptosis to cause ‘mesenchymal clearing’ and the creation of cavities in a mechanism similar to joint cavitation. We find that this is not the case, and propose that a mechanism reliant upon local nerve/blood vessel-derived restriction of ossification may

  7. Quantification of spheno-occipital synchondrosis fusion in a contemporary Malaysian population.

    Science.gov (United States)

    Hisham, Salina; Flavel, Ambika; Abdullah, Nurliza; Noor, Mohamad Helmee Mohamad; Franklin, Daniel

    2018-03-01

    Timing of fusion of the spheno-occipital synchondrosis (SOS) is correlated with age. Previous research, however, has demonstrated variation in the timing of closure among different global populations. The present study aims to quantify the timing of SOS fusion in Malaysian individuals as visualised in multi-detector computed tomography (CT) scans and to thereafter formulate age estimation models based on fusion status. Anonymised cranial CT scans of 336 males and 164 females, aged 5-25 years, were acquired from the National Institute of Forensic Medicine, Hospital Kuala Lumpur and Department of Diagnostic Imaging, Hospital Sultanah Aminah. The scans were received in DICOM format and reconstructed into three-dimensional images using OsiriX. The SOS is scored as open, fusing endocranially, fusing ectocranially or completely fused. Statistical analyses are performed using IBM SPSS Statistics version 24. Transition analysis (Nphases2) is then utilised to calculate age ranges for each stage. To assess the reliability of an observation, intra- and inter-observer agreement is quantified using Fleiss Kappa and was found to be excellent (κ=0.785-0.907 and 0.812). The mean (SD) age for complete fusion is 20.84 (2.84) years in males and 19.78 (3.35) years in females. Transition ages between Stages 0 and 1, 1 and 2, and 2 and 3 in males are 12.52, 13.98 and 15.52 years, respectively (SD 1.37); in females, the corresponding data are 10.47, 12.26 and 13.80 years (SD 1.72). Complete fusion of the SOS was observed in all individuals above the age of 18 years. SOS fusion status provides upper and lower age boundaries for forensic age estimation in the Malaysian sample. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. The Anterolateral Limit of the Occipital Lobe: An Anatomical and Imaging Study.

    Science.gov (United States)

    Reis, Cassius Vinicius C; Yagmurlu, Kaan; Elhadi, Ali M; Dru, Alexander; Lei, Ting; Gusmão, Sebastião N S; Tazinaffo, Uédson; Zabramski, Joseph M; Spetzler, Robert F; Preul, Mark C

    2016-12-01

    Objectives  The boundaries of the temporal lobe, the parietal lobe, and the anterior portion of the occipital lobe (OL) are poorly defined. Lesions in these areas can be difficult to localize. Therefore, we studied the anterolateral limit of the OL to identify reliable anatomical landmarks. Design  In 10 formalin-fixed cadaveric heads, the boundaries of the OL and relative anatomical landmarks were studied. Main Outcome Measures  Distances between the following structures were measured: (1) preoccipital tentorial plica (POTP) to the junction between lambdoid suture and superior border of the transverse sinus (POTP-SL), (2) POTP to the sinodural angle of Citelli (POTP-PP), (3) lambda to parietooccipital sulcus (L-POS), and (4) preoccipital notch to termination of the vein of Labbé (PON-VL). Landmarks in 559 computed tomography and magnetic resonance images were also studied. Results  The POTP was found on the tentorium of all anatomical specimens, located at the same coronal level as the PON and its attachment to the bony protuberance (BP) at the lateral cranial wall. The mean distances were POTP-SL, 6.5 ± 6.4 mm; POTP-PP, 18.1 ± 7.8 mm; L-POS, 10.8 ± 5.0 mm; and PON-VL, 8.8 ± 10.1 mm. Conclusion  Osseous (asterion, lambda, and BP), dural (POTP), and vascular (VL) landmarks can be used as reference structures to identify the anterolateral limit of the OL.

  9. Dissociation between conceptual and perceptual implicit memory:Evidence from patients with frontal and occipital lobe lesions

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    Liang eGong

    2016-01-01

    Full Text Available The latest neuroimaging studies about implicit memory have revealed that different implicit memory types may be processed by different parts of the brain. However, studies have rarely examined what subtypes of implicit memory processes are affected in patients with various brain-injuries. Twenty patients with frontal lobe injury, 25 patients with occipital lobe injury, and 29 healthy controls were recruited for the study. Two subtypes of implicit memory were investigated by using structurally parallel perceptual (picture identification task and conceptual (category exemplar generation task implicit memory tests in the three groups, as well as explicit memory tests. The results indicated that the priming of conceptual implicit memory and explicit memory tasks in patients with frontal lobe injury was poorer than that observed in healthy controls, while perceptual implicit memory was identical between the two groups. In contrast, the priming of perceptual implicit memory in patients with occipital lobe injury was poorer than that in healthy controls, while the priming of conceptual implicit memory and explicit memory was similar to that in healthy controls. This double dissociation between perceptual and conceptual implicit memory across the brain areas implies that occipital lobes may participate in perceptual implicit memory, while frontal lobes may be involved in processing conceptual memory.

  10. Cooperative processing in primary somatosensory cortex and posterior parietal cortex during tactile working memory.

    Science.gov (United States)

    Ku, Yixuan; Zhao, Di; Bodner, Mark; Zhou, Yong-Di

    2015-08-01

    In the present study, causal roles of both the primary somatosensory cortex (SI) and the posterior parietal cortex (PPC) were investigated in a tactile unimodal working memory (WM) task. Individual magnetic resonance imaging-based single-pulse transcranial magnetic stimulation (spTMS) was applied, respectively, to the left SI (ipsilateral to tactile stimuli), right SI (contralateral to tactile stimuli) and right PPC (contralateral to tactile stimuli), while human participants were performing a tactile-tactile unimodal delayed matching-to-sample task. The time points of spTMS were 300, 600 and 900 ms after the onset of the tactile sample stimulus (duration: 200 ms). Compared with ipsilateral SI, application of spTMS over either contralateral SI or contralateral PPC at those time points significantly impaired the accuracy of task performance. Meanwhile, the deterioration in accuracy did not vary with the stimulating time points. Together, these results indicate that the tactile information is processed cooperatively by SI and PPC in the same hemisphere, starting from the early delay of the tactile unimodal WM task. This pattern of processing of tactile information is different from the pattern in tactile-visual cross-modal WM. In a tactile-visual cross-modal WM task, SI and PPC contribute to the processing sequentially, suggesting a process of sensory information transfer during the early delay between modalities. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Sleep deprivation affects somatosensory cortex excitability as tested through median nerve stimulation.

    Science.gov (United States)

    Gorgoni, Maurizio; Ferlazzo, Fabio; Moroni, Fabio; D'Atri, Aurora; Donarelli, Stefania; Fanelli, Stefania; Gizzi Torriglia, Isabella; Lauri, Giulia; Ferrara, Michele; Marzano, Cristina; Rossini, Paolo Maria; Bramanti, Placido; De Gennaro, Luigi

    2014-01-01

    Changes of cortical excitability after sleep deprivation (SD) in humans have been investigated mostly in motor cortex, while there is little empirical evidence concerning somatosensory cortex, and its plastic changes across SD. To assess excitability of primary somatosensory cortex (S1) and EEG voltage topographical characteristics associated with somatosensory evoked potentials (SEPs) during SD. Across 41 h of SD, 16 healthy subjects participated in 4 experimental sessions (11.00 a.m. and 11.00 p.m. of the 1st and 2nd day) with: a) subjective sleepiness ratings; b) EEG recordings; c) SEPs recordings; d) behavioral vigilance responses. A clear enhancement of cortical excitability after SD was indexed by: (a) an amplitude increase of different SEPs component in S1; (b) higher voltage in occipital (around 35-43 ms) and fronto-central areas (around 47-62 ms). Circadian fluctuations did not affect cortical excitability. Voltage changes in S1 were strongly related with post-SD fluctuations of subjective and behavioral sleepiness. Sleep may have a role in keeping cortical excitability at optimal (namely below potentially dangerous) levels for the human brain, rebalancing progressive changes in cortical responsiveness to incoming inputs occurred during time spent awake. On the other hand, higher level of cortical responsiveness after sleep loss may be one of the mechanisms accounting for post-SD alterations in vigilance and behavior. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. NMDA Receptor Antagonist Ketamine Distorts Object Recognition by Reducing Feedback to Early Visual Cortex.

    Science.gov (United States)

    van Loon, Anouk M; Fahrenfort, Johannes J; van der Velde, Bauke; Lirk, Philipp B; Vulink, Nienke C C; Hollmann, Markus W; Scholte, H Steven; Lamme, Victor A F

    2016-05-01

    It is a well-established fact that top-down processes influence neural representations in lower-level visual areas. Electrophysiological recordings in monkeys as well as theoretical models suggest that these top-down processes depend on NMDA receptor functioning. However, this underlying neural mechanism has not been tested in humans. We used fMRI multivoxel pattern analysis to compare the neural representations of ambiguous Mooney images before and after they were recognized with their unambiguous grayscale version. Additionally, we administered ketamine, an NMDA receptor antagonist, to interfere with this process. Our results demonstrate that after recognition, the pattern of brain activation elicited by a Mooney image is more similar to that of its easily recognizable grayscale version than to the pattern evoked by the identical Mooney image before recognition. Moreover, recognition of Mooney images decreased mean response; however, neural representations of separate images became more dissimilar. So from the neural perspective, unrecognizable Mooney images all "look the same", whereas recognized Mooneys look different. We observed these effects in posterior fusiform part of lateral occipital cortex and in early visual cortex. Ketamine distorted these effects of recognition, but in early visual cortex only. This suggests that top-down processes from higher- to lower-level visual areas might operate via an NMDA pathway. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Anodal transcranial direct current stimulation reduces psychophysically measured surround suppression in the human visual cortex.

    Directory of Open Access Journals (Sweden)

    Daniel P Spiegel

    Full Text Available Transcranial direct current stimulation (tDCS is a safe, non-invasive technique for transiently modulating the balance of excitation and inhibition within the human brain. It has been reported that anodal tDCS can reduce both GABA mediated inhibition and GABA concentration within the human motor cortex. As GABA mediated inhibition is thought to be a key modulator of plasticity within the adult brain, these findings have broad implications for the future use of tDCS. It is important, therefore, to establish whether tDCS can exert similar effects within non-motor brain areas. The aim of this study was to assess whether anodal tDCS could reduce inhibitory interactions within the human visual cortex. Psychophysical measures of surround suppression were used as an index of inhibition within V1. Overlay suppression, which is thought to originate within the lateral geniculate nucleus (LGN, was also measured as a control. Anodal stimulation of the occipital poles significantly reduced psychophysical surround suppression, but had no effect on overlay suppression. This effect was specific to anodal stimulation as cathodal stimulation had no effect on either measure. These psychophysical results provide the first evidence for tDCS-induced reductions of intracortical inhibition within the human visual cortex.

  14. Impairment of language is related to left parieto-temporal glucose metabolism in aphasic stroke patients.

    Science.gov (United States)

    Karbe, H; Szelies, B; Herholz, K; Heiss, W D

    1990-02-01

    Twenty-six aphasic patients who had an ischaemic infarct in the territory of the left middle cerebral artery (MCA) were investigated. Cranial computed tomography (CT) showed various lesion sites: infarcts restricted to cortical structures in 12 patients, combined cortical and subcortical infarcts in 7 and isolated subcortical infarcts sparing the left cortex in another 7 cases. 18F-2-fluoro-2-deoxyglucose positron emission tomography revealed remote hypometabolism of the left convexity cortex and of the left basal ganglia, which was extended further than the morphological infarct zone in all cases. Types and degrees of aphasia were classified using the Aachener Aphasie Test (AAT): 10 patients had global aphasia, 2 Broca's, 5 Wernicke's, and 5 amnesic aphasia. Four patients suffered from minimal or residual aphasic symptoms. The AAT results were compared with the regional cerebral metabolic rates of glucose of the left hemisphere. Irrespective of the infarct location all five AAT subtests (Token test, repetition, written language, confrontation naming, auditory and reading comprehension) were closely correlated among each other and with left parieto-temporal metabolic rates, whereas left frontal and left basal ganglia metabolism showed no significant correlation. The close relation between left temporo-parietal functional activity and all five AAT subtests suggests that the different aspects of aphasia tested by AAT can be related to a common disorder of language processing in those areas.

  15. Pre-Orthographic Character String Processing and Parietal Cortex: A Role for Visual Attention in Reading?

    Science.gov (United States)

    Lobier, Muriel; Peyrin, Carole; Le Bas, Jean-Francois; Valdois, Sylviane

    2012-01-01

    The visual front-end of reading is most often associated with orthographic processing. The left ventral occipito-temporal cortex seems to be preferentially tuned for letter string and word processing. In contrast, little is known of the mechanisms responsible for pre-orthographic processing: the processing of character strings regardless of…

  16. Is the self special in the dorsomedial prefrontal cortex? An fMRI study.

    Science.gov (United States)

    Yaoi, Ken; Osaka, Naoyuki; Osaka, Mariko

    2009-01-01

    In recent years, several neuroimaging studies have suggested that the neural basis of the self-referential process1 is special, especially in the medial prefrontal cortex (MPFC). However, it remains controversial whether activity of the MPFC (and other related brain regions) appears only during the self-referential process. We investigated the neural correlates during the processing of references to the self, close other (friend), and distant other (prime minister) using fMRI. In comparison with baseline findings, referential processing to the three kinds of persons defined above showed common activation patterns in the dorsomedial prefrontal cortex (DMPFC), left middle temporal gyrus, left angular gyrus, posterior cingulate cortex and right cerebellum. Additionally, percent changes in BOLD signal in five regions of interest demonstrated the same findings. The result indicated that DMPFC was not special for the self-referential process, while there are common neural bases for evaluating the personalities of the self and others.

  17. MRI-constrained spectral imaging of benzodiazepine modulation of spontaneous neuromagnetic activity in human cortex.

    Science.gov (United States)

    Ahveninen, Jyrki; Lin, Fa-Hsuan; Kivisaari, Reetta; Autti, Taina; Hämäläinen, Matti; Stufflebeam, Steven; Belliveau, John W; Kähkönen, Seppo

    2007-04-01

    Spontaneous electromagnetic brain rhythms have been widely used in human neuropharmacology, but their applicability is complicated by the difficulties to localize their origins in the human cortex. Here, we used a novel multi-modal non-invasive imaging approach to localize lorazepam (30 microg/kg i.v.) modulation of cortical generators of spontaneous brain rhythms. Eight healthy subjects were measured with 306-channel magnetoencephalography (MEG) in a double-blind, randomized, placebo-controlled (saline), crossover design. For anatomically realistic source modeling, wavelet-transformed MEG data were combined with high-resolution MRI to constrain the current locations to the cortical mantle, after which individual data were co-registered to surface-based coordinate system for the calculation of group statistical parametric maps of drug effects. The distributed MRI-constrained MEG source estimates demonstrated decreased alpha (10 Hz) activity in and around the parieto-occipital sulcus and in the calcarine sulcus of the occipital lobe, following from increased GABA(A)-inhibition by lorazepam. Anatomically constrained spectral imaging displays the cortical loci of drug effects on oscillatory brain activity, providing a novel tool for human pharmacological neuroimaging.

  18. Asymmetric projections of the arcuate fasciculus to the temporal cortex underlie lateralized language function in the human brain

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    Shigetoshi eTakaya

    2015-09-01

    Full Text Available The arcuate fasciculus (AF in the human brain has asymmetric structural properties. However, the topographic organization of the asymmetric AF projections to the cortex and its relevance to cortical function remain unclear. Here we mapped the posterior projections of the human AF in the inferior parietal and lateral temporal cortices using surface-based structural connectivity analysis based on diffusion MRI and investigated their hemispheric differences. We then performed the cross-modal comparison with functional connectivity based on resting-state functional MRI (fMRI and task-related cortical activation based on fMRI using a semantic classification task of single words. Structural connectivity analysis showed that the left AF connecting to Broca’s area predominantly projected in the lateral temporal cortex extending from the posterior superior temporal gyrus to the mid part of the superior temporal sulcus and the middle temporal gyrus, whereas the right AF connecting to the right homologue of Broca’s area predominantly projected to the inferior parietal cortex extending from the mid part of the supramarginal gyrus to the anterior part of the angular gyrus. The left-lateralized projection regions of the AF in the left temporal cortex had asymmetric functional connectivity with Broca’s area, indicating structure-function concordance through the AF. During the language task, left-lateralized cortical activation was observed. Among them, the brain responses in the temporal cortex and Broca’s area that were connected through the left-lateralized AF pathway were specifically correlated across subjects. These results suggest that the human left AF, which structurally and functionally connects the mid temporal cortex and Broca’s area, coordinates the cortical activity in these remote cortices during a semantic decision task. The unique feature of the left AF is discussed in the context of the human capacity for language.

  19. Asymmetric projections of the arcuate fasciculus to the temporal cortex underlie lateralized language function in the human brain.

    Science.gov (United States)

    Takaya, Shigetoshi; Kuperberg, Gina R; Liu, Hesheng; Greve, Douglas N; Makris, Nikos; Stufflebeam, Steven M

    2015-01-01

    The arcuate fasciculus (AF) in the human brain has asymmetric structural properties. However, the topographic organization of the asymmetric AF projections to the cortex and its relevance to cortical function remain unclear. Here we mapped the posterior projections of the human AF in the inferior parietal and lateral temporal cortices using surface-based structural connectivity analysis based on diffusion MRI and investigated their hemispheric differences. We then performed the cross-modal comparison with functional connectivity based on resting-state functional MRI (fMRI) and task-related cortical activation based on fMRI using a semantic classification task of single words. Structural connectivity analysis showed that the left AF connecting to Broca's area predominantly projected in the lateral temporal cortex extending from the posterior superior temporal gyrus to the mid part of the superior temporal sulcus and the middle temporal gyrus, whereas the right AF connecting to the right homolog of Broca's area predominantly projected to the inferior parietal cortex extending from the mid part of the supramarginal gyrus to the anterior part of the angular gyrus. The left-lateralized projection regions of the AF in the left temporal cortex had asymmetric functional connectivity with Broca's area, indicating structure-function concordance through the AF. During the language task, left-lateralized cortical activation was observed. Among them, the brain responses in the temporal cortex and Broca's area that were connected through the left-lateralized AF pathway were specifically correlated across subjects. These results suggest that the human left AF, which structurally and functionally connects the mid temporal cortex and Broca's area in asymmetrical fashion, coordinates the cortical activity in these remote cortices during a semantic decision task. The unique feature of the left AF is discussed in the context of the human capacity for language.

  20. Multisensory and Modality Specific Processing of Visual Speech in Different Regions of the Premotor Cortex

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    Daniel eCallan

    2014-05-01

    Full Text Available Behavioral and neuroimaging studies have demonstrated that brain regions involved with speech production also support speech perception, especially under degraded conditions. The premotor cortex has been shown to be active during both observation and execution of action (‘Mirror System’ properties, and may facilitate speech perception by mapping unimodal and multimodal sensory features onto articulatory speech gestures. For this functional magnetic resonance imaging (fMRI study, participants identified vowels produced by a speaker in audio-visual (saw the speaker’s articulating face and heard her voice, visual only (only saw the speaker’s articulating face, and audio only (only heard the speaker’s voice conditions with varying audio signal-to-noise ratios in order to determine the regions of the premotor cortex involved with multisensory and modality specific processing of visual speech gestures. The task was designed so that identification could be made with a high level of accuracy from visual only stimuli to control for task difficulty and differences in intelligibility. The results of the fMRI analysis for visual only and audio-visual conditions showed overlapping activity in inferior frontal gyrus and premotor cortex. The left ventral inferior premotor cortex showed properties of multimodal (audio-visual enhancement with a degraded auditory signal. The left inferior parietal lobule and right cerebellum also showed these properties. The left ventral superior and dorsal premotor cortex did not show this multisensory enhancement effect, but there was greater activity for the visual only over audio-visual conditions in these areas. The results suggest that the inferior regions of the ventral premotor cortex are involved with integrating multisensory information, whereas, more superior and dorsal regions of the premotor cortex are involved with mapping unimodal (in this case visual sensory features of the speech signal with

  1. Learned movements in a left-handed pianist: an f-MRI evaluation.

    Science.gov (United States)

    Moretti, R; Torre, P; Antonello, R M; Ukmar, M; Longo, R; Bava, A

    2002-11-01

    The spatial arrangement of neuronal sources for digit movement is non somatotopic, and is structured as extensively arranged through different regional cortex. We have functionally examined the cerebro-cortical activation during simple and complex motor sequences, before and after learning sessions, in healthy volunteers, both considering left- and right-dominant hand use, and left non dominant hand use, skillfulness and educational level. We discuss the results with a review on the topic. Copyright 2002 Elsevier Science Ltd.

  2. Spatiotemporal integration of tactile information in human somatosensory cortex

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    Zumer Johanna M

    2007-03-01

    Full Text Available Abstract Background Our goal was to examine the spatiotemporal integration of tactile information in the hand representation of human primary somatosensory cortex (anterior parietal somatosensory areas 3b and 1, secondary somatosensory cortex (S2, and the parietal ventral area (PV, using high-resolution whole-head magnetoencephalography (MEG. To examine representational overlap and adaptation in bilateral somatosensory cortices, we used an oddball paradigm to characterize the representation of the index finger (D2; deviant stimulus as a function of the location of the standard stimulus in both right- and left-handed subjects. Results We found that responses to deviant stimuli presented in the context of standard stimuli with an interstimulus interval (ISI of 0.33s were significantly and bilaterally attenuated compared to deviant stimulation alone in S2/PV, but not in anterior parietal cortex. This attenuation was dependent upon the distance between the deviant and standard stimuli: greater attenuation was found when the standard was immediately adjacent to the deviant (D3 and D2 respectively, with attenuation decreasing for non-adjacent fingers (D4 and opposite D2. We also found that cutaneous mechanical stimulation consistently elicited not only a strong early contralateral cortical response but also a weak ipsilateral response in anterior parietal cortex. This ipsilateral response appeared an average of 10.7 ± 6.1 ms later than the early contralateral response. In addition, no hemispheric differences either in response amplitude, response latencies or oddball responses were found, independent of handedness. Conclusion Our findings are consistent with the large receptive fields and long neuronal recovery cycles that have been described in S2/PV, and suggest that this expression of spatiotemporal integration underlies the complex functions associated with this region. The early ipsilateral response suggests that anterior parietal fields also

  3. Why Dora Left

    DEFF Research Database (Denmark)

    Gammelgård, Judy

    2017-01-01

    The question of why Dora left her treatment before it was brought to a satisfactory end and the equally important question of why Freud chose to publish this problematic and fragmentary story have both been dealt with at great length by Freud’s successors. Dora has been read by analysts, literary...... critics, and not least by feminists. The aim of this paper is to point out the position Freud took toward his patient. Dora stands out as the one case among Freud’s 5 great case stories that has a female protagonist, and reading the case it becomes clear that Freud stumbled because of an unresolved...... problem toward femininity, both Dora’s and his own. In Dora, it is argued, Freud took a new stance toward the object of his investigation, speaking from the position of the master. Freud presents himself as the one who knows, in great contrast to the position he takes when unraveling the dream. Here he...

  4. Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra provides reduced effect of scanner for cortex volumetry with atlas-based method in healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masami; Ino, Kenji; Yano, Keiichi [University of Tokyo Hospital, Department of Radiological Technology, Bunkyo-ku, Tokyo (Japan); Abe, Osamu [Nihon University School of Medicine, Department of Radiology, Itabashi-ku, Tokyo (Japan); Aoki, Shigeki [Juntendo University, Department of Radiology, Bunkyo-ku, Tokyo (Japan); Hayashi, Naoto [University of Tokyo Hospital, Department of Computational Diagnostic Radiology and Preventive Medicine, Bunkyo-ku, Tokyo (Japan); Miyati, Tosiaki [Kanazawa University, Graduate School of Medical Science, Kanazawa (Japan); Takao, Hidemasa; Mori, Harushi; Kunimatsu, Akira; Ohtomo, Kuni [University of Tokyo Hospital, Department of Radiology and Department of Computational Diagnostic Radiology and Preventive Medicine, Bunkyo-ku, Tokyo (Japan); Iwatsubo, Takeshi [University of Tokyo, Department of Neuropathology, Bunkyo-ku, Tokyo (Japan); Yamashita, Fumio [Iwate Medical University, Department of Radiology, Yahaba, Iwate (Japan); Matsuda, Hiroshi [Integrative Brain Imaging Center National Center of Neurology and Psychiatry, Department of Nuclear Medicine, Kodaira, Tokyo (Japan); Collaboration: Japanese Alzheimer' s Disease Neuroimaging Initiative

    2013-07-15

    This study aimed to investigate whether the effect of scanner for cortex volumetry with atlas-based method is reduced using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) normalization compared with standard normalization. Three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects were obtained and evaluated for effect of scanner in cortex volumetry. 3D-T1WIs of the 21 subjects were obtained with five MRI systems. Imaging of each subject was performed on each of five different MRI scanners. We used the Voxel-Based Morphometry 8 tool implemented in Statistical Parametric Mapping 8 and WFU PickAtlas software (Talairach brain atlas theory). The following software default settings were used as bilateral region-of-interest labels: ''Frontal Lobe,'' ''Hippocampus,'' ''Occipital Lobe,'' ''Orbital Gyrus,'' ''Parietal Lobe,'' ''Putamen,'' and ''Temporal Lobe.'' Effect of scanner for cortex volumetry using the atlas-based method was reduced with DARTEL normalization compared with standard normalization in Frontal Lobe, Occipital Lobe, Orbital Gyrus, Putamen, and Temporal Lobe; was the same in Hippocampus and Parietal Lobe; and showed no increase with DARTEL normalization for any region of interest (ROI). DARTEL normalization reduces the effect of scanner, which is a major problem in multicenter studies. (orig.)

  5. Individual structural differences in left inferior parietal area are associated with schoolchildrens’ arithmetic scores

    Directory of Open Access Journals (Sweden)

    Yongxin eLi

    2013-12-01

    Full Text Available Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the grey matter (GM volume in the left intraparietal sulcus (IPS. Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF, bilateral inferior longitudinal fasciculus (ILF and inferior fronto-occipital fasciculus (IFOF were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children’s arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren.

  6. A rare case of atlantooccipital dissociation in the context of occipitalization of the atlas, with a 2-year follow-up: case report.

    Science.gov (United States)

    Chaudhary, Navjot; Wang, Bill H; Gurr, Kevin R; Bailey, Stewart I; Bailey, Christopher S

    2013-02-01

    Atlantooccipital dislocation (AOD) is a rare and often fatal injury. In cases of survival, residual deficits are severe and often include cranial nerve palsy, quadriplegia, or respiratory issues. Occipitalization is defined as partial or complete congenital fusion of the occiput to the atlas and is exceptionally rare. The authors present a rare case of AOD superimposed on a congenital occipitalization of the atlas. This 39-year-old man had AOD following a motor vehicle collision. On examination, his overall motor score on the American Spinal Injury Association scale was 5/100, and his rectal tone was absent. Computed tomography demonstrated AOD in an area of occipitalization. Magnetic resonance imaging revealed ligamentous injury leading to C1-2 instability. Intervention included occipital cervical instrumentation fusion from the occiput to C-3. Six months postoperatively, imaging revealed fusion of the graft and consolidation of the fractured occipitalization. At the 2-year follow-up, the patient's strength was 3/5 for wrist extension and handgrip on the right side and full strength in the rest of the myotomes. Bladder and bowel function was also normalized. A high-velocity collision led to disruption of the atlantooccipital ligaments and fracture of the occipitalized lateral masses in this patient. Internal fixation and fusion led to good fusion postoperatively. Occipitalization probably led to abnormal joint mechanics at the C1-occiput junction, which might have altered the amount of force required to fracture the occipitalization and produce AOD. This difference may partially account for the favorable neurological outcome in the featured patient compared with traditional cases of AOD.

  7. Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

    DEFF Research Database (Denmark)

    Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer

    2015-01-01

    There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right...... the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input–output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms...... excitability and PPC–M1 connectivity and is a new approach to modify motor excitability and sensorimotor interaction....

  8. CEREBRAL CORTEX DAMAGE INDUCED BY ACUTE ORAL ...

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... Keywords: Brain, cerebral cortex, alcohol, Wistar rats, oxidative stress. INTRODUCTION. The prefrontal cortex is ... damage, memory loss, sleep disorders and psychosis, with or without ..... and emotional consequences of binge drinking: Role of amygdala and prefrontal cortex. Philos Trans R Soc Lond Biol ...

  9. The Functions of the Orbitofrontal Cortex

    Science.gov (United States)

    Rolls, Edmund T.

    2004-01-01

    The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight…

  10. Calcificação intracraniana occipital bilateral, epilepsia e doença celíaca: relato de caso Bilateral occipital calcification, epilepsy and coeliac disease: case report

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Souza Santos

    2002-09-01

    Full Text Available Relatamos o caso de uma menina com 6 anos de idade que apresentava episódios recorrentes de diarréia desde os 6 meses de vida associada a anemia ferropriva com desenvolvimento neuromotor normal. Aos 3 anos de idade começou a apresentar crises parciais que foram controladas com carbamazepina. Tomografia computadorizada de crânio aos 5 anos demonstrou calcificações girais grosseiras nas regiões occipital e parietal posterior bilateralmente. A ressonância magnética de crânio evidenciou áreas de hipossinal em T2 na região parieto-occipital bilateralmente. Realizou investigação para síndrome de mal absorção incluindo estudo da função digestivo/absortiva (teste D-xilose, avaliação sorológica (anticorpos antigliadina, antiendomísio e antitransglutaminase e biopsia de intestino delgado que demonstrou intensa atrofia de vilosidades com infiltrado linfoplasmocitário no córion compatível com doença celíaca.We report a case of a six-year-old girl with frequent diarrhea episodes associated with ferroprive anemia from 6 months of age, normal neuromotor development and partial seizures initiated in her 3rd year which was controlled with carbamazepine. CT scan in her 5th year of age demonstrated gyral calcifications in the occipital and posterior parietal regions bilaterally. MRI has shown low signal areas in the axial T2 sequences corresponding to the gyral calcifications evident on the CT. Blood investigation for coeliac disease with antigliadin, endomysial and transglutaminase antibodies was positive and the intestinal biopsy has showed villous atrophy associated with an increased number of intraepithelial lymphocytes and hypertrophic criptae compatible with coeliac disease.

  11. A case of left-sided unilateral spatial neglect owing to the cerebral infarction in the distribution of the right posterior cerebral artery

    International Nuclear Information System (INIS)

    Odagaki, Yuji; Oka, Iori; Kon, Yutaka; Asano, Yutaka

    1985-01-01

    We report a case of left-sided unilateral spatial neglect (USN) induced by the cerebral infarction in the distribution of right posterior cerebral artery (PCA). A 69-year-old, right-handed man, who had had a sudden onset of left hemiparesis in August 1983, was admitted to our hospital on January 16, 1984, because of nocturnal delirium. He became alert a few days after admission, but was euphoric and sometimes irritable. Neurologic examination disclosed left homonymous hemianopsia, dysarthria, left central facial weakness, spastic left hemiparesis, hyperactive reflexes on the left with no Babinski sign, left hemisensory loss, and left thalamic pain. On neuropsychologic examination it was revealed that he had a tendency to neglect the left half of his extrapersonal space. When asked to locate cities on a blank map of Japan, he located most of them not only on the right side of the map but also incorrectly. He also had a severe acalculia. There was gradual improvement in these neuropsychologic symptoms. CT demonstrated an area of decreased density in the territory of the right PCA, posterolateral portion of the right thalamus, and the posterior limb of right internal capsule, sparing parietal and temporal lobes. Single-photon emission computed tomography (SPECT) using the Xenon-133 inhalation method showed, however, diminished regional cerebral blood flow (rCBF) in an area larger than the area of infarction demonstrated by CT, including the right parieto-temporo-occipital junctional area, which has been considerd to be responsible for left-sided USN. The authors ascribed the patient's left-sided USN to the lesion of this area that was revealed not morphologically by CT but functionally by SPECT, although the possibility that the lesions of the medial portion of the right occipital lobe and/or subcortical lesions of such areas as the thalamus and the internal capsule more or less influenced the neuropsychologic symptoms could not be excluded. (author)

  12. Non-compact left ventricle/hypertrabeculated left ventricle

    International Nuclear Information System (INIS)

    Restrepo, Gustavo; Castano, Rafael; Marmol, Alejandro

    2005-01-01

    Non-compact left ventricle/hypertrabeculated left ventricle is a myocardiopatie produced by an arrest of the normal left ventricular compaction process during the early embryogenesis. It is associated to cardiac anomalies (congenital cardiopaties) as well as to extracardial conditions (neurological, facial, hematologic, cutaneous, skeletal and endocrinological anomalies). This entity is frequently unnoticed, being diagnosed only in centers with great experience in the diagnosis and treatment of myocardiopathies. Many cases of non-compact left ventricle have been initially misdiagnosed as hypertrophic myocardiopatie, endocardial fibroelastosis, dilated cardiomyopatie, restrictive cardiomyopathy and endocardial fibrosis. It is reported the case of a 74 years old man with a history of chronic arterial hypertension and diabetes mellitus, prechordial chest pain and mild dyspnoea. An echocardiogram showed signs of non-compact left ventricle with prominent trabeculations and deep inter-trabecular recesses involving left ventricular apical segment and extending to the lateral and inferior walls. Literature on this topic is reviewed

  13. Mechanical discordance between left atrium and left atrial appendage

    Directory of Open Access Journals (Sweden)

    Arash Khamooshian

    2018-01-01

    Full Text Available During standard transesophageal echocardiographic examinations in sinus rhythm (SR patients, the left atrial appendage (LAA is not routinely assessed with Doppler. Despite having a SR, it is still possible to have irregular activity in the LAA. This situation is even more important for SR patients where assessment of the left atrium is often foregone. We describe a case where we encountered this situation and briefly review how to assess the left atrium and its appendage in such a case scenario.

  14. Functional asymmetry in primary auditory cortex for processing musical sounds: temporal pattern analysis of fMRI time series.

    Science.gov (United States)

    Izumi, Shuji; Itoh, Kosuke; Matsuzawa, Hitoshi; Takahashi, Sugata; Kwee, Ingrid L; Nakada, Tsutomu

    2011-07-13

    Hemispheric differences in the temporal processing of musical sounds within the primary auditory cortex were investigated using functional magnetic resonance imaging (fMRI) time series analysis on a 3.0 T system in right-handed individuals who had no formal training in music. The two hemispheres exhibited a clear-cut asymmetry in the time pattern of fMRI signals. A large transient signal component was observed in the left primary auditory cortex immediately after the onset of musical sounds, while only sustained activation, without an initial transient component, was seen in the right primary auditory cortex. The observed difference was believed to reflect differential segmentation in primary auditory cortical sound processing. Although the left primary auditory cortex processed the entire 30-s musical sound stimulus as a single event, the right primary auditory cortex had low-level processing of sounds with multiple segmentations of shorter time scales. The study indicated that musical sounds are processed as 'sounds with contents', similar to how language is processed in the left primary auditory cortex.

  15. [Left-handedness and health].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  16. Occipital nerve stimulation with the Bion® microstimulator for the treatment of medically refractory chronic cluster headache.

    Science.gov (United States)

    Strand, Natalie H; Trentman, Terrence L; Vargas, Bert B; Dodick, David W

    2011-01-01

    Chronic cluster headache is a severely disabling neurological disorder. Evidence from open-label case series suggest that occipital nerve stimulation may be effective for the treatment of chronic cluster headache. To evaluate the effectiveness of a microstimulator for chronic cluster headache. Prospective, observational feasibility study plus medical record review. Academic medical center. Four patients with medically refractory chronic cluster headache underwent implantation of a unilateral bion microstimulator. In-person follow-up was conducted for 12 months after implantation, and a prospective follow-up chart review was carried out to assess long term outcome. Three of the participants returned their headache diaries for evaluation. The mean duration of chronic cluster headache was 14.3 years (range 3 to 29 years). Pain was predominantly or exclusively retroocular/periocular. One participant demonstrated a positive response (> 50% reduction in cluster headache frequency) at 3 months post-implant, while there were 2 responders at 6 months. At least one of the participants continued to show > 60% reduction in headache frequency at 12 months. A chart review showed that at 58-67 months post-implant, all 3 participants reported continued use and benefit from stimulation. No side-shift in attacks was noted in any participant. Adverse events were limited to 2 participants with neck pain and/or cramping with stimulation at high amplitudes; one required revision for a faulty battery. Small patient population without control group. Not blinded or randomized. Unilateral occipital nerve stimulation, using a minimally invasive microstimulator, may be effective for the treatment of medically refractory chronic cluster headache. This benefit may occur immediately after implantation, remain sustained up to 5 years after implantation, and occur despite the anterior location of the pain. Prospective, randomized controlled trials of occipital nerve stimulation in chronic cluster

  17. Abordaje fisioterapéutico en la neuralgia occipital. Revisión bibliográfica.

    OpenAIRE

    Albalate Narro, María

    2017-01-01

    Introducción. La neuralgia occipital (ON) corresponde a un dolor unilateral o bilateral a nivel de la parte posterior del cuero cabelludo que sigue el recorrido de los nervios occipitales (mayor, menor y tercero), aunque puede irradiar a otras zonas. Se caracteriza por ser paroxístico o punzante, puede cursar con síntomas asociados y se produce por compresión y/o irritación de los citados nervios por causas muy diversas. La incidencia y la prevalencia de esta patología no han sido estudiadas ...

  18. Abnormal prefrontal cortex resting state functional connectivity and severity of internet gaming disorder.

    Science.gov (United States)

    Jin, Chenwang; Zhang, Ting; Cai, Chenxi; Bi, Yanzhi; Li, Yangding; Yu, Dahua; Zhang, Ming; Yuan, Kai

    2016-09-01

    Internet Gaming Disorder (IGD) among adolescents has become an important public concern and gained more and more attention internationally. Recent studies focused on IGD and revealed brain abnormalities in the IGD group, especially the prefrontal cortex (PFC). However, the role of PFC-striatal circuits in pathology of IGD remains unknown. Twenty-five adolescents with IGD and 21 age- and gender-matched healthy controls were recruited in our study. Voxel-based morphometric (VBM) and functional connectivity analysis were employed to investigate the abnormal structural and resting-state properties of several frontal regions in individuals with online gaming addiction. Relative to healthy comparison subjects, IGD subjects showed significant decreased gray matter volume in PFC regions including the bilateral dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and the right supplementary motor area (SMA) after controlling for age and gender effects. We chose these regions as the seeding areas for the resting-state analysis and found that IGD subjects showed decreased functional connectivity between several cortical regions and our seeds, including the insula, and temporal and occipital cortices. Moreover, significant decreased functional connectivity between some important subcortical regions, i.e., dorsal striatum, pallidum, and thalamus, and our seeds were found in the IGD group and some of those changes were associated with the severity of IGD. Our results revealed the involvement of several PFC regions and related PFC-striatal circuits in the process of IGD and suggested IGD may share similar neural mechanisms with substance dependence at the circuit level.

  19. Visual cortex in aging and Alzheimer’s disease: Changes in visual field maps and population receptive fields

    Directory of Open Access Journals (Sweden)

    Alyssa A. Brewer

    2014-02-01

    Full Text Available Although several studies have suggested that cortical alterations underlie such age-related visual deficits as decreased acuity, little is known about what changes actually occur in visual cortex during healthy aging. Two recent studies showed changes in primary visual cortex (V1 during normal aging; however, no studies have characterized the effects of aging on visual cortex beyond V1, important measurements both for understanding the aging process and for comparison to changes in age-related diseases. Similarly, there is almost no information about changes in visual cortex in Alzheimer’s disease (AD, the most common form of dementia. Because visual deficits are often reported as one of the first symptoms of AD, measurements of such changes in the visual cortex of AD patients might improve our understanding of how the visual system is affected by neurodegeneration as well as aid early detection, accurate diagnosis and timely treatment of AD. Here we use fMRI to first compare the visual field map (VFM organization and population receptive fields (pRFs between young adults and healthy aging subjects for occipital VFMs V1, V2, V3, and hV4. Healthy aging subjects do not show major VFM organizational deficits, but do have reduced surface area and increased pRF sizes in the foveal representations of V1, V2, and hV4 relative to healthy young control subjects. These measurements are consistent with behavioral deficits seen in healthy aging. We then demonstrate the feasibility and first characterization of these measurements in two patients with mild AD, which reveal potential changes in visual cortex as part of the pathophysiology of AD. Our data aid in our understanding of the changes in the visual processing pathways in normal aging and provide the foundation for future research into earlier and more definitive detection of AD.

  20. Homosexual women have less grey matter in perirhinal cortex than heterosexual women.

    Directory of Open Access Journals (Sweden)

    Jorge Ponseti

    2007-08-01

    Full Text Available Is sexual orientation associated with structural differences in the brain? To address this question, 80 homosexual and heterosexual men and women (16 homosexual men and 15 homosexual women underwent structural MRI. We used voxel-based morphometry to test for differences in grey matter concentration associated with gender and sexual orientation. Compared with heterosexual women, homosexual women displayed less grey matter bilaterally in the temporo-basal cortex, ventral cerebellum, and left ventral premotor cortex. The relative decrease in grey matter was most prominent in the left perirhinal cortex. The left perirhinal area also showed less grey matter in heterosexual men than in heterosexual women. Thus, in homosexual women, the perirhinal cortex grey matter displayed a more male-like structural pattern. This is in accordance with previous research that revealed signs of sex-atypical prenatal androgenization in homosexual women, but not in homosexual men. The relevance of the perirhinal area for high order multimodal (olfactory and visual object, social, and sexual processing is discussed.

  1. Homosexual women have less grey matter in perirhinal cortex than heterosexual women.

    Science.gov (United States)

    Ponseti, Jorge; Siebner, Hartwig R; Klöppel, Stefan; Wolff, Stephan; Granert, Oliver; Jansen, Olav; Mehdorn, Hubertus M; Bosinski, Hartmut A

    2007-08-22

    Is sexual orientation associated with structural differences in the brain? To address this question, 80 homosexual and heterosexual men and women (16 homosexual men and 15 homosexual women) underwent structural MRI. We used voxel-based morphometry to test for differences in grey matter concentration associated with gender and sexual orientation. Compared with heterosexual women, homosexual women displayed less grey matter bilaterally in the temporo-basal cortex, ventral cerebellum, and left ventral premotor cortex. The relative decrease in grey matter was most prominent in the left perirhinal cortex. The left perirhinal area also showed less grey matter in heterosexual men than in heterosexual women. Thus, in homosexual women, the perirhinal cortex grey matter displayed a more male-like structural pattern. This is in accordance with previous research that revealed signs of sex-atypical prenatal androgenization in homosexual women, but not in homosexual men. The relevance of the perirhinal area for high order multimodal (olfactory and visual) object, social, and sexual processing is discussed.

  2. Dissociation of Detection and Discrimination of Pure Tones following Bilateral Lesions of Auditory Cortex

    Science.gov (United States)

    Dykstra, Andrew R.; Koh, Christine K.; Braida, Louis D.; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5±2.1 dB in the left ear and 6.5±1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6±0.22 dB; right ear: 1.7±0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed. PMID:22957087

  3. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Science.gov (United States)

    Dykstra, Andrew R; Koh, Christine K; Braida, Louis D; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  4. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Directory of Open Access Journals (Sweden)

    Andrew R Dykstra

    Full Text Available It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB. The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  5. Distinct timescales of population coding across cortex.

    Science.gov (United States)

    Runyan, Caroline A; Piasini, Eugenio; Panzeri, Stefano; Harvey, Christopher D

    2017-08-03

    The cortex represents information across widely varying timescales. For instance, sensory cortex encodes stimuli that fluctuate over few tens of milliseconds, whereas in association cortex behavioural choices can require the maintenance of information over seconds. However, it remains poorly understood whether diverse timescales result mostly from features intrinsic to individual neurons or from neuronal population activity. This question remains unanswered, because the timescales of coding in populations of neurons have not been studied extensively, and population codes have not been compared systematically across cortical regions. Here we show that population codes can be essential to achieve long coding timescales. Furthermore, we find that the properties of population codes differ between sensory and association cortices. We compared coding for sensory stimuli and behavioural choices in auditory cortex and posterior parietal cortex as mice performed a sound localization task. Auditory stimulus information was stronger in auditory cortex than in posterior parietal cortex, and both regions contained choice information. Although auditory cortex and posterior parietal cortex coded information by tiling in time neurons that were transiently informative for approximately 200 milliseconds, the areas had major differences in functional coupling between neurons, measured as activity correlations that could not be explained by task events. Coupling among posterior parietal cortex neurons was strong and extended over long time lags, whereas coupling among auditory cortex neurons was weak and short-lived. Stronger coupling in posterior parietal cortex led to a population code with long timescales and a representation of choice that remained consistent for approximately 1 second. In contrast, auditory cortex had a code with rapid fluctuations in stimulus and choice information over hundreds of milliseconds. Our results reveal that population codes differ across cortex

  6. An effect of bilingualism on the auditory cortex.

    Science.gov (United States)

    Ressel, Volker; Pallier, Christophe; Ventura-Campos, Noelia; Díaz, Begoña; Roessler, Abeba; Ávila, César; Sebastián-Gallés, Núria

    2012-11-21

    Two studies (Golestani et al., 2007; Wong et al., 2008) have reported a positive correlation between the ability to perceive foreign speech sounds and the volume of Heschl's gyrus (HG), the structure that houses the auditory cortex. More precisely, participants with larger left Heschl's gyri learned consonantal or tonal contrasts faster than those with smaller HG. These studies leave open the question of the impact of experience on HG volumes. In the current research, we investigated the effect of early language exposure on Heschl's gyrus by comparing Spanish-Catalan bilinguals who have been exposed to two languages since childhood, to a group of Spanish monolinguals matched in education, socio-economic status, and musical experience. Manual volumetric measurements of HG revealed that bilinguals have, on average, larger Heschl's gyri than monolinguals. This was corroborated, for the left Heschl's gyrus, by a voxel-based morphometry analysis showing larger gray matter volumes in bilinguals than in monolinguals. Since the bilinguals in this study were not a self-selected group, this observation provides a clear demonstration that learning a second language is a causal factor in the increased size of the auditory cortex.

  7. Eye muscle proprioception is represented bilaterally in the sensorimotor cortex

    Science.gov (United States)

    Balslev, Daniela; Albert, Neil B.; Miall, Chris

    2016-01-01

    The cortical representation of eye position is still uncertain. In the monkey a proprioceptive representation of the extraocular muscles (EOM) of an eye were recently found within the contralateral central sulcus. In humans, we have previously shown a change in the perceived position of the right eye after a virtual lesion with rTMS over the left somatosensory area. However, it is possible that the proprioceptive representation of the EOM extends to other brain sites, which were not examined in these previous studies. The aim of this fMRI study was to sample the whole brain to identify the proprioceptive representation for the left and the right eye separately. Data were acquired while passive eye movement was used to stimulate EOM proprioceptors in the absence of a motor command. We also controlled for the tactile stimulation of the eyelid by removing from the analysis voxels activated by eyelid touch alone. For either eye, the brain area commonly activated by passive and active eye movement was located bilaterally in the somatosensory area extending into the motor and premotor cytoarchitectonic areas. We suggest this is where EOM proprioception is processed. The bilateral representation for either eye contrasts with the contralateral representation of hand proprioception. We suggest that the proprioceptive representation of the two eyes next to each other in either somatosensory cortex and extending into the premotor cortex reflects the integrative nature of the eye position sense, which combines proprioceptive information across the two eyes with the efference copy of the oculomotor command. PMID:21391252

  8. Anatomy of the inferior petro-occipital vein and its relation to the base of the skull: application to surgical and endovascular procedures of the skull base.

    Science.gov (United States)

    Tubbs, R Shane; Watanabe, Koichi; Loukas, Marios; Cohen-Gadol, Aaron A

    2014-07-01

    Although the inferior petro-occipital vein has been recently used for vascular access to the cavernous sinus, few detailed descriptions of its anatomy are in the literature. We aimed to investigate the morphology and relationships of this vessel. Twelve latex-injected cadaveric heads (24 sides) were dissected to identify the inferior petro-occipital vein and anatomic details documented. The petro-occipital vein was identified on 83.3% of sides. Generally this vein united the internal carotid venous plexus to the superior jugular bulb. However, on 10% of sides, the anterior part of this vein communicated directly with the cavernous sinus, and on 15%, the posterior vein drained into the inferior petrosal sinus at its termination into the superior jugular bulb. The petro-occipital vein was separated from the overlying inferior petrosal sinus by a thin plate of bone. On 40% of sides, small venous connections were found between these two venous structures. The vein was usually larger if a nondominant transverse sinus was present. The overlying inferior petrosal sinus was smaller in diameter when an underlying inferior petro-occipital vein was present. On 20% of sides, the posterior aspect of the vein communicated with the hypoglossal canal veins. On three sides, diploic veins from the clivus drained into the inferior petro-occipital vein. The inferior petro-occipital vein is present in most humans. This primarily extracranial vessel communicates with intracranial venous sinuses and should be considered an emissary vein. Knowledge of this vessel's exact anatomy may be useful to cranial base surgeons and endovascular specialists. Copyright © 2013 Wiley Periodicals, Inc.

  9. Pivotal role of anterior cingulate cortex in working memory after traumatic brain injury in youth

    Directory of Open Access Journals (Sweden)

    Fabienne eCazalis

    2011-01-01

    Full Text Available In this fMRI study, the functions of the Anterior Cingulate Cortex were studied in a group of adolescents who had sustained a moderate to severe Traumatic Brain Injury. A spatial working memory task with varying working memory loads, representing experimental conditions of increasing difficulty, was administered.In a cross-sectional comparison bet