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Sample records for parietal lobe areas

  1. The mirror mechanism in the parietal lobe.

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    Rizzolatti, Giacomo; Rozzi, Stefano

    2018-01-01

    The mirror mechanism is a basic mechanism that transforms sensory representations of others' actions into motor representations of the same actions in the brain of the observer. The mirror mechanism plays an important role in understanding actions of others. In the present chapter we discuss first the basic organization of the posterior parietal lobe in the monkey, stressing that it is best characterized as a motor scaffold, on the top of which sensory information is organized. We then describe the location of the mirror mechanism in the posterior parietal cortex of the monkey, and its functional role in areas PFG, and anterior, ventral, and lateral intraparietal areas. We will then present evidence that a similar functional organization is present in humans. We will conclude by discussing the role of the mirror mechanism in the recognition of action performed with tools. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Xenomelia: a new right parietal lobe syndrome.

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    McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

    2011-12-01

    Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

  3. Use of explicit memory cues following parietal lobe lesions.

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    Dobbins, Ian G; Jaeger, Antonio; Studer, Bettina; Simons, Jon S

    2012-11-01

    The putative role of the lateral parietal lobe in episodic memory has recently become a topic of considerable debate, owing primarily to its consistent activation for studied materials during functional magnetic resonance imaging studies of recognition. Here we examined the performance of patients with parietal lobe lesions using an explicit memory cueing task in which probabilistic cues ("Likely Old" or "Likely New"; 75% validity) preceded the majority of verbal recognition memory probes. Without cues, patients and control participants did not differ in accuracy. However, group differences emerged during the "Likely New" cue condition with controls responding more accurately than parietal patients when these cues were valid (preceding new materials) and trending towards less accuracy when these cues were invalid (preceding old materials). Both effects suggest insufficient integration of external cues into memory judgments on the part of the parietal patients whose cued performance largely resembled performance in the complete absence of cues. Comparison of the parietal patients to a patient group with frontal lobe lesions suggested the pattern was specific to parietal and adjacent area lesions. Overall, the data indicate that parietal lobe patients fail to appropriately incorporate external cues of novelty into recognition attributions. This finding supports a role for the lateral parietal lobe in the adaptive biasing of memory judgments through the integration of external cues and internal memory evidence. We outline the importance of such adaptive biasing through consideration of basic signal detection predictions regarding maximum possible accuracy with and without informative environmental cues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Visuo-spatial construction in patients with frontal and parietal lobe lesions

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    Himani Kashyap

    2011-04-01

    Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

  5. Temporal order processing of syllables in the left parietal lobe.

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    Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

    2009-10-07

    Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere.

  6. Kinesthetic alexia due to left parietal lobe lesions.

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    Ihori, Nami; Kawamura, Mitsuru; Araki, Shigeo; Kawachi, Juro

    2002-01-01

    To investigate the neuropsychological mechanisms of kinesthetic alexia, we asked 7 patients who showed kinesthetic alexia with preserved visual reading after damage to the left parietal region to perform tasks consisting of kinesthetic written reproduction (writing down the same letter as the kinesthetic stimulus), kinesthetic reading aloud, visual written reproduction (copying letters), and visual reading aloud of hiragana (Japanese phonograms). We compared the performance in these tasks and the lesion sites in each patient. The results suggested that deficits in any one of the following functions might cause kinesthetic alexia: (1) the retrieval of kinesthetic images (motor engrams) of characters from kinesthetic stimuli, (2) kinesthetic images themselves, (3) access to cross-modal association from kinesthetic images, and (4) cross-modal association itself (retrieval of auditory and visual images from kinesthetic images of characters). Each of these factors seemed to be related to different lesion sites in the left parietal lobe. Copyright 2002 S. Karger AG, Basel

  7. Short parietal lobe connections of the human and monkey brain

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    Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

    2017-01-01

    projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

  8. Gyri of the human parietal lobe: Volumes, spatial extents, automatic labelling, and probabilistic atlases.

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    Heather M Wild

    Full Text Available Accurately describing the anatomy of individual brains enables interlaboratory communication of functional and developmental studies and is crucial for possible surgical interventions. The human parietal lobe participates in multimodal sensory integration including language processing and also contains the primary somatosensory area. We describe detailed protocols to subdivide the parietal lobe, analyze morphological and volumetric characteristics, and create probabilistic atlases in MNI152 stereotaxic space. The parietal lobe was manually delineated on 3D T1 MR images of 30 healthy subjects and divided into four regions: supramarginal gyrus (SMG, angular gyrus (AG, superior parietal lobe (supPL and postcentral gyrus (postCG. There was the expected correlation of male gender with larger brain and intracranial volume. We examined a wide range of anatomical features of the gyri and the sulci separating them. At least a rudimentary primary intermediate sulcus of Jensen (PISJ separating SMG and AG was identified in nearly all (59/60 hemispheres. Presence of additional gyri in SMG and AG was related to sulcal features and volumetric characteristics. The parietal lobe was slightly (2% larger on the left, driven by leftward asymmetries of the postCG and SMG. Intersubject variability was highest for SMG and AG, and lowest for postCG. Overall the morphological characteristics tended to be symmetrical, and volumes also tended to covary between hemispheres. This may reflect developmental as well as maturation factors. To assess the accuracy with which the labels can be used to segment newly acquired (unlabelled T1-weighted brain images, we applied multi-atlas label propagation software (MAPER in a leave-one-out experiment and compared the resulting automatic labels with the manually prepared ones. The results showed strong agreement (mean Jaccard index 0.69, corresponding to a mean Dice index of 0.82, average mean volume error of 0.6%. Stereotaxic

  9. [Neuroanatomy of the Parietal Association Areas].

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    Kobayashi, Yasushi

    2016-11-01

    The parietal association cortex comprises the superior and inferior parietal lobules, the precuneus and the cortices in the intraparietal, parietooccipital and lunate sulci. By processing somatic, visual, acoustic and vestibular sensory information, the parietal association cortex plays a pivotal role in spatial cognition and motor control of the eyes and the extremities. Sensory information from the primary and secondary somatosensory areas enters the superior parietal lobule and is transferred to the inferior parietal lobule. Visual information is processed through the dorsal visual pathway and it reaches the inferior parietal lobule, the intraparietal sulcus and the precuneus. Acoustic information is transferred posteriorly from the primary acoustic area, and it reaches the posterior region of the inferior parietal lobule. The areas in the intraparietal sulcus project to the premotor area, the frontal eye fields, and the prefrontal area. These areas are involved in the control of ocular movements, reaching and grasping of the upper extremities, and spatial working memory. The posterior region of the inferior parietal lobule and the precuneus both project either directly, or indirectly via the posterior cingulate gyrus, to the parahippocampal and entorhinal cortices. Both these areas are strongly associated with hippocampal functions for long-term memory formation.

  10. Noninvasive brain stimulation of the parietal lobe for improving neurologic, neuropsychologic, and neuropsychiatric deficits.

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    Bolognini, Nadia; Miniussi, Carlo

    2018-01-01

    Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) are noninvasive brain stimulation (NIBS) tools that are now widely used in neuroscientific research in humans. The fact that both TMS and tES are able to modulate brain plasticity and, in turn, affect behavior is opening up new horizons in the treatment of brain circuit and plasticity disorders. In the present chapter, we will first provide the reader with a brief background on the basic principles of NIBS, describing the electromagnetic and physical foundations of TMS and tES, as well as the current knowledge of the neurophysiologic basis of their effects on brain activity and plasticity. In the main part, we will outline studies aimed at improving persistent symptoms and deficits in patients suffering from neurologic and neuropsychiatric disorders featured by dysfunction of the parietal lobe. The emerging view is that NIBS of parietal areas holds the promise to overcome various sensory, motor, and cognitive disorders that are often refractory to standard medical or behavioral therapies. The chapter closes with an outlook on further developments in this realm, discussing novel therapeutic approaches that could lead to more effective rehabilitation procedures, better suited for the specific parietal lobe dysfunction. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

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    Fatemeh Mirsafi; Gholamreza Kaka; Mahnaz Azarnia

    2017-01-01

    Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group rec...

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

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    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.

  13. Metabolic Hyperactivity of the Medial Posterior Parietal Lobes in Psychogenic Tremor

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    Peter Hedera

    2012-05-01

    Full Text Available Background: The pathophysiology of psychogenic movement disorders, including psychogenic tremor (PT, is only emerging. Case Report: This is a single case report of a patient who met diagnostic criteria for PT. He underwent positron emission tomography (PET of brain with 18F-deoxyglucose at resting state. His PET study showed symmetrically increased 18F-deoxyglucose uptake in both posterior medial parietal lobes. There was no corresponding abnormality on structural imaging. Discussion: Hypermetabolism of the medial aspects of posterior parietal lobes bilaterally may reflect abnormal activity of sensory integration that is important in the pathogenesis of PT. This further supports the idea that non-organic movement disorders may be associated with detectable functional brain abnormalities.

  14. Anatomical substrates of the alerting, orienting and executive control components of attention: focus on the posterior parietal lobe.

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    Xuntao Yin

    Full Text Available Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI data in normal participants, and evaluated their attention performance using attention network test (ANT, which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

  15. Neural correlates of temporal credit assignment in the parietal lobe.

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    Timothy M Gersch

    Full Text Available Empirical studies of decision making have typically assumed that value learning is governed by time, such that a reward prediction error arising at a specific time triggers temporally-discounted learning for all preceding actions. However, in natural behavior, goals must be acquired through multiple actions, and each action can have different significance for the final outcome. As is recognized in computational research, carrying out multi-step actions requires the use of credit assignment mechanisms that focus learning on specific steps, but little is known about the neural correlates of these mechanisms. To investigate this question we recorded neurons in the monkey lateral intraparietal area (LIP during a serial decision task where two consecutive eye movement decisions led to a final reward. The underlying decision trees were structured such that the two decisions had different relationships with the final reward, and the optimal strategy was to learn based on the final reward at one of the steps (the "F" step but ignore changes in this reward at the remaining step (the "I" step. In two distinct contexts, the F step was either the first or the second in the sequence, controlling for effects of temporal discounting. We show that LIP neurons had the strongest value learning and strongest post-decision responses during the transition after the F step regardless of the serial position of this step. Thus, the neurons encode correlates of temporal credit assignment mechanisms that allocate learning to specific steps independently of temporal discounting.

  16. Multimodal responses induced by cortical stimulation of the parietal lobe: a stereo-electroencephalography study.

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    Balestrini, Simona; Francione, Stefano; Mai, Roberto; Castana, Laura; Casaceli, Giuseppe; Marino, Daniela; Provinciali, Leandro; Cardinale, Francesco; Tassi, Laura

    2015-09-01

    The functional complexity of the parietal lobe still represents a challenge for neurophysiological and functional neuroimaging studies. While the somatosensory functions of the anterior parietal cortex are well established, the posterior parietal cortex has a relevant role in processing the sensory information, including visuo-spatial perception, visual attention, visuo-motor transformations and other complex and not completely understood functions. We retrospectively analysed all the clinical manifestations induced by intracerebral bipolar electrical stimulation in 172 patients suffering from drug-resistant focal epilepsy (mean age 25.6, standard deviation 11.6; 44% females and 56% males) with at least one electrode stereotactically implanted in the parietal cortex. A total of 1186 electrical stimulations were included in the analysis, of which 88 were subsequently excluded because of eliciting pathological electric activity or inducing ictal symptomatology. In the dominant parietal lobe, clinical responses were observed for 56 (25%) of the low-frequency stimulations and for 76 (50%) of the high-frequency stimulations. In the non-dominant parietal lobe, 111 (27%) low-frequency and 176 (55%) high-frequency stimulations were associated with a clinical response. Body scheme alteration was the only clinical effect showing a lateralization, as they were evoked only in the non-dominant hemisphere. The occurrence of somatosensory sensations, motor symptoms, dysarthria and multimodal responses were significantly associated with stimulation of the postcentral gyrus (odds ratio: 5.83, P < 0.001; odds ratio: 8.77, P < 0.001; odds ratio: 5.44, P = 0.011; odds ratio: 8.33, P = 0.006; respectively). Stimulation of the intraparietal sulcus was associated with the occurrence of sensory illusions or hallucinations (odds ratio: 8.68, P < 0.001) and eyeball/eyelid movements or sensations (odds ratio: 4.35, P = 0.047). To our knowledge, this is the only currently available complete

  17. Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

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    Chen TY

    2013-07-01

    Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

  18. Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

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    Sheremata, Summer L; Somers, David C; Shomstein, Sarah

    2018-02-07

    Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

  19. The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

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    Battelli, Lorella; Alvarez, George A.; Carlson, Thomas; Pascual-Leone, Alvaro

    2009-01-01

    Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of…

  20. Recency Effects in the Inferior Parietal Lobe during Verbal Recognition Memory

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    Bradley Russell Buchsbaum

    2011-07-01

    Full Text Available The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such recency effects have shown that activation in the lateral inferior parietal cortex (LIPC tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging (fMRI we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and expectancy hypotheses, respectively -- of the parietal lobe recency effect.

  1. The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

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    Fatemeh Mirsafi

    2017-05-01

    Full Text Available Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group received no injections, the sham group received intraperitoneal injections of distilled water solution containing salt and polysorbate (solvent of levothyroxine, and the experimental group received once-daily, intraperitoneal injections of 0.5 mg/kg levothyroxine for a 10-day period to become hyperthyroid rats. The hyperthyroid rats were then mated, and all pregnant rats were killed on the 20th day of gestation. Fetuses were removed, fixed, and processed for histological procedures. The fetuses were sagitally sectioned at 5 µ thickness and stained with hematoxylin-eosin (H and E technique. The sections were examined using a light microscope and Motic software. Results The results showed no significant difference in the studied variables between the sham and control groups. A significantly increase in body weight and a significant decrease in crown-rump length of embryos was observed in the experimental group when compared to the control group. The mean total thickness of the parietal cortex, ventricular layer, and intermediate layer of embryos showed a significant decrease in the experimental group compared to the control and sham groups. The mean number of cells also showed a significant decrease in the intermediate and ventricular layers in the experimental group compared to the control and sham groups. Conclusions This study showed that maternal hyperthyroidism leads to a reduction in development of the parietal cortex in embryos. Maternal hyperthyroidism can disturb the growth and development of embryos.

  2. Patterns of morphological integration between parietal and temporal areas in the human skull.

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    Bruner, Emiliano; Pereira-Pedro, Ana Sofia; Bastir, Markus

    2017-10-01

    Modern humans have evolved bulging parietal areas and large, projecting temporal lobes. Both changes, largely due to a longitudinal expansion of these cranial and cerebral elements, were hypothesized to be the result of brain evolution and cognitive variations. Nonetheless, the independence of these two morphological characters has not been evaluated. Because of structural and functional integration among cranial elements, changes in the position of the temporal poles can be a secondary consequence of parietal bulging and reorientation of the head axis. In this study, we use geometric morphometrics to test the correlation between parietal shape and the morphology of the endocranial base in a sample of adult modern humans. Our results suggest that parietal proportions show no correlation with the relative position of the temporal poles within the spatial organization of the endocranial base. The vault and endocranial base are likely to be involved in distinct morphogenetic processes, with scarce or no integration between these two districts. Therefore, the current evidence rejects the hypothesis of reciprocal morphological influences between parietal and temporal morphology, suggesting that evolutionary spatial changes in these two areas may have been independent. However, parietal bulging exerts a visible effect on the rotation of the cranial base, influencing head position and orientation. This change can have had a major relevance in the reorganization of the head functional axis. © 2017 Wiley Periodicals, Inc.

  3. Emotion unfolded by motion: a role for parietal lobe in decoding dynamic facial expressions.

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    Sarkheil, Pegah; Goebel, Rainer; Schneider, Frank; Mathiak, Klaus

    2013-12-01

    Facial expressions convey important emotional and social information and are frequently applied in investigations of human affective processing. Dynamic faces may provide higher ecological validity to examine perceptual and cognitive processing of facial expressions. Higher order processing of emotional faces was addressed by varying the task and virtual face models systematically. Blood oxygenation level-dependent activation was assessed using functional magnetic resonance imaging in 20 healthy volunteers while viewing and evaluating either emotion or gender intensity of dynamic face stimuli. A general linear model analysis revealed that high valence activated a network of motion-responsive areas, indicating that visual motion areas support perceptual coding for the motion-based intensity of facial expressions. The comparison of emotion with gender discrimination task revealed increased activation of inferior parietal lobule, which highlights the involvement of parietal areas in processing of high level features of faces. Dynamic emotional stimuli may help to emphasize functions of the hypothesized 'extended' over the 'core' system for face processing.

  4. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

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    Maeshima, S.; Matsumoto, T.; Ueyoshi, A. [Department of Physical Medicine and Rehabilitation, Wakayama Medical University, Wakayama (Japan); Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H. [Department of Neurological Surgery, Hidaka General Hospital, Wakayama (Japan); Roger, P. [School of Communication Sciences and Disorders, University of Sydney, Sydney, NSW (Australia)

    2002-02-01

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  5. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

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    Maeshima, S.; Matsumoto, T.; Ueyoshi, A.; Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H.; Roger, P.

    2002-01-01

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  6. Temporo-Parietal and Fronto-Parietal Lobe Contributions to Theory of Mind and Executive Control: An fMRI Study of Verbal Jokes

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    Yu-Chen eChan

    2015-09-01

    Full Text Available ‘Getting a joke’ always requires resolving an apparent incongruity but the particular cognitive operations called upon vary depending on the nature of the joke itself. Previous research has identified the primary neural correlates of the cognitive and affective processes called upon to respond to humor generally, but little work has been done on the substrates underlying the distinct cognitive operations required to comprehend particular joke types. This study explored the neural correlates of the cognitive processes required to successfully comprehend three joke types: bridging-inference jokes, exaggeration jokes and ambiguity jokes. For all joke types, the left dlPFC appeared to support common cognitive mechanisms, such as script-shifting, while the vACC was associated with affective appreciation. The temporo-parietal lobe (TPJ and MTG was associated with bridging-inference jokes, suggesting involvement of these regions with ‘theory of mind’ processing. The ventral fronto-parietal lobe (IPL and IFG was associated with both exaggeration and ambiguity jokes, suggesting that it supports executive control processes such as retrieval from episodic memory, self-awareness, and language-based decoding. The social-affective appreciation of verbal jokes was associated with activity in the orbitofrontal cortex, amygdala, ventral anterior cingulate cortex (vACC, and parahippocampal gyrus. These results allow a more precise account of the neural

  7. Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

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    Andrew D. Robertson

    2017-09-01

    Full Text Available Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL magnetic resonance imaging (MRI in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF and the spatial coefficient of variation of CBF (sCoV were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73 and excellent reliability for sCoV (ICC = 0.94. In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036. The greatest change occurred in the parietal lobe (+18 ± 12%. Gray matter sCoV, however, did not change following training (P = 0.31. This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

  8. Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

    Science.gov (United States)

    Robertson, Andrew D.; Marzolini, Susan; Middleton, Laura E.; Basile, Vincenzo S.; Oh, Paul I.; MacIntosh, Bradley J.

    2017-01-01

    Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries. PMID:29033829

  9. Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

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    Magrassi, Lorenzo; Bongetta, Daniele; Bianchini, Simonetta; Berardesca, Marta; Arienta, Cesare

    2010-07-30

    Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Modulation of Speech Motor Learning with Transcranial Direct Current Stimulation of the Inferior Parietal Lobe

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    Mickael L. D. Deroche

    2017-12-01

    Full Text Available The inferior parietal lobe (IPL is a region of the cortex believed to participate in speech motor learning. In this study, we investigated whether transcranial direct current stimulation (tDCS of the IPL could influence the extent to which healthy adults (1 adapted to a sensory alteration of their own auditory feedback, and (2 changed their perceptual representation. Seventy subjects completed three tasks: a baseline perceptual task that located the phonetic boundary between the vowels /e/ and /a/; a sensorimotor adaptation task in which subjects produced the word “head” under conditions of altered or unaltered feedback; and a post-adaptation perceptual task identical to the first. Subjects were allocated to four groups which differed in current polarity and feedback manipulation. Subjects who received anodal tDCS to their IPL (i.e., presumably increasing cortical excitability lowered their first formant frequency (F1 by 10% in opposition to the upward shift in F1 in their auditory feedback. Subjects who received the same stimulation with unaltered feedback did not change their production. Subjects who received cathodal tDCS to their IPL (i.e., presumably decreasing cortical excitability showed a 5% adaptation to the F1 alteration similar to subjects who received sham tDCS. A subset of subjects returned a few days later to reiterate the same protocol but without tDCS, enabling assessment of any facilitatory effects of the previous tDCS. All subjects exhibited a 5% adaptation effect. In addition, across all subjects and for the two recording sessions, the phonetic boundary was shifted toward the vowel /e/ being repeated, consistently with the selective adaptation effect, but a correlation between perception and production suggested that anodal tDCS had enhanced this perceptual shift. In conclusion, we successfully demonstrated that anodal tDCS could (1 enhance the motor adaptation to a sensory alteration, and (2 potentially affect the

  11. Development of rostral inferior parietal lobule area functional connectivity from late childhood to early adulthood.

    Science.gov (United States)

    Wang, Mengxing; Zhang, Jilei; Dong, Guangheng; Zhang, Hui; Lu, Haifeng; Du, Xiaoxia

    2017-06-01

    Although the mirror neuron system (MNS) has been extensively studied in monkeys and adult humans, very little is known about its development. Previous studies suggest that the MNS is present by infancy and that the brain and MNS-related cognitive abilities (such as language, empathy, and imitation learning) continue to develop after childhood. In humans, the PFt area of the inferior parietal lobule (IPL) seems to particularly correlate with the functional properties of the PF area in primates, which contains mirror neurons. However, little is known about the functional connectivity (FC) of the PFt area with other brain areas and whether these networks change over time. Here, we investigated the FC development of the PFt area-based network in 59 healthy subjects aged 7-26 years at resting-state to study brain development from late childhood through adolescence to early adulthood. The bilateral PFt showed similar core FC networks, which included the frontal lobe, the cingulate gyri, the insula, the somatosensory cortex, the precuneus, the superior and inferior parietal lobules, the temporal lobe, and the cerebellum posterior lobes. Furthermore, the FC between the left PFt and the left IPL exhibited a significantly positive correlation with age, and the FC between the left PFt and the right postcentral gyrus exhibited a significantly negative correlation with age. In addition, the FC between the right PFt and the right putamen exhibited a significantly negative correlation with age. Our findings suggest that the PFt area-based network develops and is reorganized with age. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  12. [Brodmann Areas 39 and 40: Human Parietal Association Area and Higher Cortical Function].

    Science.gov (United States)

    Sakurai, Yasuhisa

    2017-04-01

    The anatomy and function of the angular gyrus (Brodmann Area 39) and supramarginal gyrus (Brodmann Area 40) are described here. Both gyri constitute the inferior part of the parietal lobe. Association fibers from the angular gyrus project to the dorsolateral prefrontal cortex via the superior longitudinal fasciculus (SLF) II/arcuate fasciculus (AF), whereas those from the supramarginal gyrus project to the ventrolateral prefrontal cortex via SLF III/AF. Damage to the left angular gyrus causes kanji agraphia (lexical agraphia) and mild anomia, whereas damage to the left supramarginal gyrus causes kana alexia (phonological dyslexia) and kana agraphia (phonological agraphia). Damage to either gyrus causes Gerstmann's syndrome (finger agnosia, left-right disorientation, agraphia and acalculia) and verbal short-term memory impairment. "Angular alexia with agraphia" results from damage to the middle occipital gyrus posterior to the angular gyrus. Alexia and agraphia, with lesions in the angular or supramarginal gyrus, are characterized by kana transposition errors in reading words, which suggests the impairment of sequential phonological processing.

  13. Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content.

    Science.gov (United States)

    Eimontaite, Iveta; Goel, Vinod; Raymont, Vanessa; Krueger, Frank; Schindler, Igor; Grafman, Jordan

    2018-05-14

    To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive

  14. Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

    Science.gov (United States)

    Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

    2018-04-18

    Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

  15. Parietal Lobe Volume Deficits in Adolescents with Schizophrenia and Adolescents with Cannabis Use Disorders

    Science.gov (United States)

    Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin

    2012-01-01

    Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…

  16. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

    Science.gov (United States)

    Iuculano, Teresa; Cohen Kadosh, Roi

    2014-01-01

    Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small-yet constant-current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education.

  17. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

    Directory of Open Access Journals (Sweden)

    Teresa eIuculano

    2014-02-01

    Full Text Available Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD, which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small – yet constant – current through the brain, a non-invasive technique named transcranial electrical stimulation (tES. Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC. The first subject (DD1 received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance’s improvements in healthy subjects. The second subject (DD2 received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i automaticity of number processing; and (ii mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation

  18. Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

    Science.gov (United States)

    Gimbel, Sarah I; Brewer, James B

    2014-01-01

    Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7), posterior ventral (BA 39), and anterior ventral (BA 40) regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

  19. Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

    Directory of Open Access Journals (Sweden)

    Sarah I Gimbel

    Full Text Available Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7, posterior ventral (BA 39, and anterior ventral (BA 40 regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

  20. Dysfunctional role of parietal lobe during self-face recognition in schizophrenia.

    Science.gov (United States)

    Yun, Je-Yeon; Hur, Ji-Won; Jung, Wi Hoon; Jang, Joon Hwan; Youn, Tak; Kang, Do-Hyung; Park, Sohee; Kwon, Jun Soo

    2014-01-01

    Anomalous sense of self is central to schizophrenia yet difficult to demonstrate empirically. The present study examined the effective neural network connectivity underlying self-face recognition in patients with schizophrenia (SZ) using [15O]H2O Positron Emission Tomography (PET) and Structural Equation Modeling. Eight SZ and eight age-matched healthy controls (CO) underwent six consecutive [15O]H2O PET scans during self-face (SF) and famous face (FF) recognition blocks, each of which was repeated three times. There were no behavioral performance differences between the SF and FF blocks in SZ. Moreover, voxel-based analyses of data from SZ revealed no significant differences in the regional cerebral blood flow (rCBF) levels between the SF and FF recognition conditions. Further effective connectivity analyses for SZ also showed a similar pattern of effective connectivity network across the SF and FF recognition. On the other hand, comparison of SF recognition effective connectivity network between SZ and CO demonstrated significantly attenuated effective connectivity strength not only between the right supramarginal gyrus and left inferior temporal gyrus, but also between the cuneus and right medial prefrontal cortex in SZ. These findings support a conceptual model that posits a causal relationship between disrupted self-other discrimination and attenuated effective connectivity among the right supramarginal gyrus, cuneus, and prefronto-temporal brain areas involved in the SF recognition network of SZ. © 2013.

  1. Novelty enhances visual salience independently of reward in the parietal lobe.

    Science.gov (United States)

    Foley, Nicholas C; Jangraw, David C; Peck, Christopher; Gottlieb, Jacqueline

    2014-06-04

    Novelty modulates sensory and reward processes, but it remains unknown how these effects interact, i.e., how the visual effects of novelty are related to its motivational effects. A widespread hypothesis, based on findings that novelty activates reward-related structures, is that all the effects of novelty are explained in terms of reward. According to this idea, a novel stimulus is by default assigned high reward value and hence high salience, but this salience rapidly decreases if the stimulus signals a negative outcome. Here we show that, contrary to this idea, novelty affects visual salience in the monkey lateral intraparietal area (LIP) in ways that are independent of expected reward. Monkeys viewed peripheral visual cues that were novel or familiar (received few or many exposures) and predicted whether the trial will have a positive or a negative outcome--i.e., end in a reward or a lack of reward. We used a saccade-based assay to detect whether the cues automatically attracted or repelled attention from their visual field location. We show that salience--measured in saccades and LIP responses--was enhanced by both novelty and positive reward associations, but these factors were dissociable and habituated on different timescales. The monkeys rapidly recognized that a novel stimulus signaled a negative outcome (and withheld anticipatory licking within the first few presentations), but the salience of that stimulus remained high for multiple subsequent presentations. Therefore, novelty can provide an intrinsic bonus for attention that extends beyond the first presentation and is independent of physical rewards. Copyright © 2014 the authors 0270-6474/14/347947-11$15.00/0.

  2. Diffusion Tensor Magnetic Resonance Imaging Finding of Discrepant Fractional Anisotropy Between the Frontal and Parietal Lobes After Whole-Brain Irradiation in Childhood Medulloblastoma Survivors: Reflection of Regional White Matter Radiosensitivity?

    International Nuclear Information System (INIS)

    Qiu Deqiang; Kwong, Dora; Chan, Godfrey; Leung, Lucullus; Khong, P.-L.

    2007-01-01

    Purpose: To test the hypothesis that fractional anisotropy (FA) is more severely reduced in white matter of the frontal lobe compared with the parietal lobe after receiving the same whole-brain irradiation dose in a cohort of childhood medulloblastoma survivors. Methods and Materials: Twenty-two medulloblastoma survivors (15 male, mean [± SD] age = 12.1 ± 4.6 years) and the same number of control subjects (15 male, aged 12.0 ± 4.2 years) were recruited for diffusion tensor magnetic resonance imaging scans. Using an automated tissue classification method and the Talairach Daemon atlas, FA values of frontal and parietal lobes receiving the same radiation dose, and the ratio between them were quantified and denoted as FFA, PFA, and FA f/p , respectively. The Mann-Whitney U test was used to test for significant differences of FFA, PFA, and FA f/p between medulloblastoma survivors and control subjects. Results: Frontal lobe and parietal lobe white matter FA were found to be significantly less in medulloblastoma survivors compared with control subjects (frontal p = 0.001, parietal p = 0.026). Moreover, these differences were found to be discrepant, with the frontal lobe having a significantly larger difference in FA compared with the parietal lobe. The FA f/p of control and medulloblastoma survivors was 1.110 and 1.082, respectively (p = 0.029). Conclusion: Discrepant FA changes after the same irradiation dose suggest radiosensitivity of the frontal lobe white matter compared with the parietal lobe. Special efforts to address the potentially vulnerable frontal lobe after treatment with whole-brain radiation may be needed so as to balance disease control and treatment-related morbidity

  3. [Functional mapping using subdural electrodes combined with monitoring during awake craniotomy enabled preservation of function and extensive resection of a glioma adjacent to the parietal lobe language sites: a case report].

    Science.gov (United States)

    Takebayashi, Kento; Saito, Taiichi; Nitta, Masayuki; Tamura, Manabu; Maruyama, Takashi; Muragaki, Yoshihiro; Okada, Yoshikazu

    2015-01-01

    Surgical resection of gliomas located in the dominant parietal lobe is difficult because this lesion is surrounded by multiple functional areas. Although functional mapping during awake craniotomy is very useful for resection of gliomas adjacent to eloquent areas, the limited time available makes it difficult to sufficiently evaluate multiple functions, such as language, calculative ability, distinction of right and left sides, and finger recognition. Here, we report a case of anaplastic oligodendroglioma, which was successfully treated with a combination of functional mapping using subdural electrodes and monitoring under awake craniotomy for glioma. A 32-year-old man presented with generalized seizure. Magnetic resonance imaging revealed a non-enhanced tumor in the left angular and supramarginal gyri. In addition, the tumor showed high accumulation on 11C-methionine positron emission tomography(PET)(tumor/normal brain tissue ratio=3.20). Preparatory mapping using subdural electrodes showed absence of brain function on the tumor lesion. Surgical removal was performed using cortical mapping during awake craniotomy with an updated navigation system using intraoperative magnetic resonance imaging(MRI). The tumor was resected until aphasia was detected by functional monitoring, and the extent of tumor resection was 93%. The patient showed transient transcortical aphasia and Gerstmann's syndrome after surgery but eventually recovered. The pathological diagnosis was anaplastic oligodendroglioma, and the patient was administered chemo-radiotherapy. The patient has been progression free for more than 2 years. The combination of subdural electrode mapping and monitoring during awake craniotomy is useful in order to achieve preservation of function and extensive resection for gliomas in the dominant parietal lobe.

  4. Connections of the medial posterior parietal cortex (area 7m) in the monkey.

    Science.gov (United States)

    Leichnetz, G R

    2001-06-01

    The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

  5. At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory

    Science.gov (United States)

    Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

    2011-01-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients’ memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. PMID:21345344

  6. At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory.

    Science.gov (United States)

    Berryhill, Marian E; Chein, Jason; Olson, Ingrid R

    2011-04-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients' memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

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    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.

  8. It's how you get there: Walking down a virtual alley activates premotor and parietal areas

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    Johanna eWagner

    2014-02-01

    Full Text Available Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12Hz, 15-20Hz and 23-40Hz was significantly (p ≤ 0.05 decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05 from baseline in the frequency range 23-40Hz during walking. These modulations were significantly (p ≤ 0.05 reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions.We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

  9. A Model of Self-Organizing Head-Centered Visual Responses in Primate Parietal Areas

    Science.gov (United States)

    Mender, Bedeho M. W.; Stringer, Simon M.

    2013-01-01

    We present a hypothesis for how head-centered visual representations in primate parietal areas could self-organize through visually-guided learning, and test this hypothesis using a neural network model. The model consists of a competitive output layer of neurons that receives afferent synaptic connections from a population of input neurons with eye position gain modulated retinal receptive fields. The synaptic connections in the model are trained with an associative trace learning rule which has the effect of encouraging output neurons to learn to respond to subsets of input patterns that tend to occur close together in time. This network architecture and synaptic learning rule is hypothesized to promote the development of head-centered output neurons during periods of time when the head remains fixed while the eyes move. This hypothesis is demonstrated to be feasible, and each of the core model components described is tested and found to be individually necessary for successful self-organization. PMID:24349064

  10. Parietal scalp is another affected area in female pattern hair loss: an analysis of hair density and hair diameter

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    Rojhirunsakool S

    2017-12-01

    Full Text Available Salinee Rojhirunsakool, Poonkiat Suchonwanit Department of Medicine, Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Female pattern hair loss (FPHL is a common hair disease. However, studies of the quantitative measurement of FPHL are still limited. The aim of this study was to investigate the characteristics of hair density and hair diameter in normal women and FPHL patients, and further correlate the quantitative measurement with the clinical presentation of FPHL.Patients and methods: An evaluation of 471 FPHL patients and 236 normal women was carried out according to the Ludwig classification, and analysis was performed by using a computerized handheld USB camera with computer-assisted software. Various areas of the scalp, including frontal, parietal, midscalp, and occipital, were analyzed for hair density, non-vellus hair diameter, and percentage of miniaturized hair.Results: The hair density in normal women was the highest and the lowest in the midscalp and parietal areas, respectively. The FPHL group revealed the lowest hair density in the parietal area. Significant differences in hair density, non-vellus hair diameter, and percentage of miniaturized hair between the normal and FPHL groups were observed, especially in the midscalp and parietal areas.Conclusion: The parietal area is another important affected area in FPHL in addition to the midscalp area. This finding provides novel important information of FPHL and will be useful for hair transplant surgeons choosing the optimal donor sites for hair transplantation in women. Keywords: androgenetic alopecia, alopecia, phototrichogram, miniaturization

  11. Spatial summation in macaque parietal area 7a follows a winner-take-all rule

    NARCIS (Netherlands)

    Oleksiak, Anna; Klink, P. Christiaan; Postma, Albert; van der Ham, Ineke J.M.; Lankheet, Martin J.M.; van Wezel, Richard Jack Anton

    2011-01-01

    While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable

  12. The role of frontal and parietal brain areas in bistable perception

    NARCIS (Netherlands)

    Knapen, T.; Brascamp, J.; Pearson, J.; van Ee, R.; Blake, R.

    2011-01-01

    When sensory input allows for multiple, competing perceptual interpretations, observers' perception can fluctuate over time, which is called bistable perception. Imaging studies in humans have revealed transient responses in a right-lateralized network in the frontal-parietal cortex (rFPC) around

  13. Comparative proteomic analyses of the parietal lobe from rhesus monkeys fed a high-fat/sugar diet with and without resveratrol supplementation, relative to a healthy diet: Insights into the roles of unhealthy diets and resveratrol on function.

    Science.gov (United States)

    Swomley, Aaron M; Triplett, Judy C; Keeney, Jeriel T; Warrier, Govind; Pearson, Kevin J; Mattison, Julie A; de Cabo, Rafael; Cai, Jian; Klein, Jon B; Butterfield, D Allan

    2017-01-01

    A diet consisting of a high intake of saturated fat and refined sugars is characteristic of a Western-diet and has been shown to have a substantial negative effect on human health. Expression proteomics were used to investigate changes to the parietal lobe proteome of rhesus monkeys consuming either a high fat and sugar (HFS) diet, a HFS diet supplemented with resveratrol (HFS+RSV), or a healthy control diet for 2 years. Here we discuss the modifications in the levels of 12 specific proteins involved in various cellular systems including metabolism, neurotransmission, structural integrity, and general cellular signaling following a nutritional intervention. Our results contribute to a better understanding of the mechanisms by which resveratrol functions through the up- or down-regulation of proteins in different cellular sub-systems to affect the overall health of the brain. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Projections to early visual areas V1 and V2 in the calcarine fissure from parietal association areas in the macaque.

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    Elena eBorra

    2011-06-01

    Full Text Available Non-extrastriate projections to area V1 in monkeys, now demonstrated by several anatomical studies, are potential substrates of physiologically documented multisensory effects in primary sensory areas. The full network of projections among association and primary areas, however, is likely to be complex and is still only partially understood. In the present report, we used the anterograde tracer biotinylated dextran amine to investigate projections to areas V1 and V2 from subdivisions of the parietal association cortex in macaque. Parietal cortex was chosen to allow comparisons between projections from this higher association area and from other previously reported areas. In addition, we were interested in further elucidating pathways to areas V1 and V2 from parietal areas, as potentially contributing to attention and active vision. Of eight cases, three brains had projections only to area V2, and the five others projected to both areas V1 and V2. Terminations in area V1 were sparse. These were located in supragranular layers I, II, upper III; occasionally in IVB; and in layer VI. Terminations in V2 were denser, and slightly more prevalent in the supragranular layers. For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field. By reconstructions of single axons, we demonstrated that four of nine axons had collaterals, either to V1 and V2 (n=1 or to area V1 and a ventral area likely to be TEO (n=3. In area V1, axons extended divergently in layer VI as well as layer I. Overall, these and previous results suggest a nested connectivity architecture, consisting of multiple direct and indirect recurrent projections from association areas to area V1. Terminations in area V1 are not abundant, but could be potentiated by the network of indirect connections.

  15. Reorganization of Language Areas in Patient with a Frontal Lobe Low Grade Glioma – fMRI Case Study

    International Nuclear Information System (INIS)

    Kośla, Katarzyna; Bryszewski, Bartosz; Jaskólski, Dariusz; Błasiak-Kołacińska, Nina; Stefańczyk, Ludomir; Majos, Agata

    2015-01-01

    Functional magnetic resonance (fMRI) studies results in case of an adult patient with low grade glioma (LGG) in dominant hemisphere suggest brain plasticity process with acquisition of language functions by the non-dominant hemisphere speech regions. A 36-years old right-handed woman was admitted to the Department of Neurosurgery for surgical treatment of brain tumor. An MRI examination revealed a pathological mass in the left frontal lobe, in close topographical relationship to the Broca’s area. A left fronto-parietal craniotomy was performed, with an intraoperative awake language mapping procedure. A total resection of the pathological mass was achieved. The tumor was examined histologically as LGG. In the follow-up MRI exam 32 months after the operation a tumor recurrence was suggested. The fMRI exams performed preoperative and 3, 32 and 41 months after the operation showed changes in language regions activation patterns, with a progressive right-sided activation of Broca’s and Wernicke’s areas. Pre- and postoperative cognitive evaluation by a neuropsychologist did not detect any language impairment. We present a running process of reorganization of language areas in a patient after brain tumor resection, from strong left-sided to symmetrical lateralization. 1. FMRI results in comparison with the psychological status of the patient proved contribution of functional reorganization to the preservation of language performance. 2. A slow growing LGG as well as the recurrence of the tumor near the left Broca’s area might be the factors leading to reorganization of language-related areas by recruiting the right hemisphe

  16. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-06-01

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

  19. Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

    Science.gov (United States)

    Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

    2013-04-01

    Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

  20. Controversies over the mechanisms underlying the crucial role of the left fronto-parietal areas in the representation of tools

    Directory of Open Access Journals (Sweden)

    Guido eGainotti

    2013-10-01

    Full Text Available Anatomo-clinical and neuroimaging data show that the left fronto-parietal areas play an important role in representing tools. As manipulation is an important source of knowledge about tools, it has been assumed that motor activity explains the link between tool knowledge and the left fronto-parietal areas. However, controversies exist over the exact mechanisms underlying this relationship. According to a strong version of the ‘embodied cognition theory’, activation of a tool concept necessarily involves re-enactment of the corresponding kind of action. Impairment of the ability to use tools should, therefore, lead to impairment of tool knowledge. Both the ‘domains of knowledge hypothesis’ and the ‘sensory-motor model of conceptual knowledge’ refute the strong version of the ‘embodied cognition hypothesis’ but acknowledge that manipulation and other action schemata play an important role in our knowledge of tools. The basic difference between these two models is that the former is based on an innatist model and the latter holds that the brain’s organization of categories is experience dependent. Data supporting and arguing against each of these models are briefly reviewed. In particular, the following lines of research, which argue against the innate nature of the brain’s categorical organization, are discussed: (1 the observation that in patients with category-specific disorders the semantic impairment does not respect the boundaries between biological entities and artefact items; (2 data showing that experience-driven neuroplasticity in musicians is not confined to alterations of perceptual and motor maps but also leads to the establishment of higher-level semantic representations for musical instruments; (3 results of experiments using previously unfamiliar materials showing that the history of our sensory-motor experience with an object significantly affects its neural representation.

  1. Abnormal activation of the occipital lobes during emotion picture processing in major depressive disorder patients

    Science.gov (United States)

    Li, Jianying; Xu, Cheng; Cao, Xiaohua; Gao, Qiang; Wang, Yan; Wang, Yanfang; Peng, Juyi; Zhang, Kerang

    2013-01-01

    A large number of studies have demonstrated that depression patients have cognitive dysfunction. With recently developed brain functional imaging, studies have focused on changes in brain function to investigate cognitive changes. However, there is still controversy regarding abnormalities in brain functions or correlation between cognitive impairment and brain function changes. Thus, it is important to design an emotion-related task for research into brain function changes. We selected positive, neutral, and negative pictures from the International Affective Picture System. Patients with major depressive disorder were asked to judge emotion pictures. In addition, functional MRI was performed to synchronously record behavior data and imaging data. Results showed that the total correct rate for recognizing pictures was lower in patients compared with normal controls. Moreover, the consistency for recognizing pictures for depressed patients was worse than normal controls, and they frequently recognized positive pictures as negative pictures. The consistency for recognizing pictures was negatively correlated with the Hamilton Depression Rating Scale. Functional MRI suggested that the activation of some areas in the frontal lobe, temporal lobe, parietal lobe, limbic lobe, and cerebellum was enhanced, but that the activation of some areas in the frontal lobe, parietal lobe and occipital lobe was weakened while the patients were watching positive and neutral pictures compared with normal controls. The activation of some areas in the frontal lobe, temporal lobe, parietal lobe, and limbic lobe was enhanced, but the activation of some areas in the occipital lobe were weakened while the patients were watching the negative pictures compared with normal controls. These findings indicate that patients with major depressive disorder have negative cognitive disorder and extensive brain dysfunction. Thus, reduced activation of the occipital lobe may be an initiating factor for

  2. Three cases of acute encephalopathy with low density areas in the occipital lobes on CT

    International Nuclear Information System (INIS)

    Nakajima, Masako; Nakano, Chizuko; Takakura, Hiroki; Otani, Kyoichi.

    1985-01-01

    Three female infants with acute encephalopathy (aged from 5 months to 1 year and 8 months) are presented in whom peculiar features were obtained on cranial CT. Disturbances of consciousness and spasm were seen in all patients. Although two patients had been in good health until the onset, the other patient had had nodular sclerosis. Laboratory data showed no evidence of inflammation in the spinal fluid, but increased levels of transaminase and LDH. CT around 7 days after the onset revealed diffuse low density areas. This was noted in the temporal and occipital lobes, mainly resulting from edema. Follow-up CT examinations revealed localized low density areas corresponding to the surface area, being probably attributable to disturbances of the arterial and venous circulations. In two patients with severe disturbances of consciousness, low density areas became more marked with time. (Namekawa, K.)

  3. [Mirror movement due to the medial frontal lobe lesion].

    Science.gov (United States)

    Takahashi, N; Kawamura, M; Hirayama, K

    1995-01-01

    We reported a case with acquired mirror movement in upper limbs due to the lesion of right medial frontal lobe including supplementary motor area, and also discussed a possible mechanism underlying it. A 59-year-old right-handed woman developed left hemiparesis caused by cerebral hemorrhage in the right frontoparietal lobe, on April 5, 1981. She had right hemiparesis and right hemianopsia due to cerebral hemorrhage in the left parieto-occipital lobe, 13 days later. As the patient was recovering from paresis, mirror movement appeared on upper limbs. The features of the mirror movement of this case are summarized as follows: (1) it appeared when using both proximal and distal region of upper limbs; (2) it appeared on left upper limb when the patient intended to move right upper limb or on right upper limb when intended to move left upper limb, while it appeared predominantly in the former; and (3) it was more remarkably found in habitual movement using gesture and pantomimic movement for the use of objects, and it was found in lower degree when actual object was used or when the patient tried to imitate the gesture of the examiner. The lesions in MRI were found in medial region of right frontal lobe (supplementary motor area, medial region of motor area, and cingulate gyrus), right medial parietal lobe, posterior region of right occipital lobe, and medial regions of left parietal and occipital lobes. There was no apparent abnormality in corpus callosum.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

    International Nuclear Information System (INIS)

    Pandya, D.N.; Seltzer, B.

    1982-01-01

    By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

  5. Etomidate accurately localizes the epileptic area in patients with temporal lobe epilepsy.

    Science.gov (United States)

    Pastor, Jesús; Wix, Rybel; Meilán, María Luisa; Martínez-Chacón, José Luís; de Dios, Eva; Domínguez-Gadea, Luis; Herrera-Peco, Iván; Sola, Rafael G

    2010-04-01

    A variety of drugs have been used to activate and identify the epileptogenic area in patients during presurgical evaluation. We have evaluated the safety and usefulness of etomidate in identifying the epileptic zone by measuring bioelectrical brain activity and cerebral blood flow (CBF). We studied 13 men and 9 women under presurgical evaluation for temporal lobe epilepsy. We applied etomidate (0.1 mg/kg) while patients were monitored by video-electroencephalography (VEEG) with foramen ovale electrodes. In a subset of 15 patients, we also measured CBF with single photon emission computed tomography (SPECT). (1) Etomidate induced seizures in 2 of 22 patients. (2) The main side-effects observed were myoclonus (14 of 20) and moderate pain (3 of 20). (3) No changes in capillary oxygen saturation, respiration, or heart rate were observed. (4) Irritative activity specifically increased in the temporal mesial and lateral areas. No spikes were observed in other areas, aside from those observed under baseline conditions. (5) Irritative activity induced by etomidate correctly lateralized the ictal onset zone in 19 of 20 patients. In addition, the two etomidate-induced seizures appeared in the same regions as spontaneous ones. (6) The kinetics of pharmacologically induced activity was higher in the region of the ictal-onset zone. (7) Etomidate increased the CBF in the basal ganglia and especially in the posterior hippocampus of the temporal mesial region contralateral to the ictal-onset zone. Etomidate activation is a safe, specific, and quick test that can be used to identify the epileptic region in patients evaluated as candidates for temporal lobe epilepsy surgery.

  6. Decrease in N-acetylaspartate/creatine ratio in the motor area and the frontal lobe in amyotrophic lateral sclerosis

    International Nuclear Information System (INIS)

    Abe, K.; Takanashi, M.; Yanagihara, T.; Watanabe, Y.; Tanaka, H.; Fujita, N.; Hirabuki, N.

    2001-01-01

    We studied whether N-acetylaspartate (NAA), a neuronal marker, is reduced in the brain of 14 patients with clinically definite amyotrophic lateral sclerosis (ALS) and whether NAA levels in the motor area and frontal lobe correlate with the clinical features, including frontal lobe function. We also studied 14 normal controls were evaluated. We obtained peak integrals in 1 H magnetic resonance spectroscopy (MRS) for NAA, creatine (Cr), and choline-containing compounds (Cho). Severity of the disease was determined using the manual muscle strength test, and the Norris limb and bulbar scales. In the patients, the NAA/Cr ratio was reduced in the motor area and frontal lobe, while the Cho/Cr ratio was normal throughout the brain. There were significant correlations between the NAA/Cr ratio in the motor area and the Norris limb scale (r = 0.50; P < 0.01) and between the NAA/Cr ratio in the frontal lobe and the number of categories achieved in the Wisconsin Card Sorting test (r = 0.71; P < 0.05), implying frontal lobe dysfunction. These correlations suggest that a reduced NAA/Cr ratio is a marker of cortical neuronal loss and dysfunction in ALS. (orig.)

  7. Decrease in N-acetylaspartate/creatine ratio in the motor area and the frontal lobe in amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Takanashi, M.; Yanagihara, T. [Dept. of Neurology, Osaka University Graduate School of Medicine (Japan); Watanabe, Y.; Tanaka, H.; Fujita, N.; Hirabuki, N. [Dept. of Radiology, Osaka University Graduate School of Medicine (Japan)

    2001-07-01

    We studied whether N-acetylaspartate (NAA), a neuronal marker, is reduced in the brain of 14 patients with clinically definite amyotrophic lateral sclerosis (ALS) and whether NAA levels in the motor area and frontal lobe correlate with the clinical features, including frontal lobe function. We also studied 14 normal controls were evaluated. We obtained peak integrals in {sup 1}H magnetic resonance spectroscopy (MRS) for NAA, creatine (Cr), and choline-containing compounds (Cho). Severity of the disease was determined using the manual muscle strength test, and the Norris limb and bulbar scales. In the patients, the NAA/Cr ratio was reduced in the motor area and frontal lobe, while the Cho/Cr ratio was normal throughout the brain. There were significant correlations between the NAA/Cr ratio in the motor area and the Norris limb scale (r = 0.50; P < 0.01) and between the NAA/Cr ratio in the frontal lobe and the number of categories achieved in the Wisconsin Card Sorting test (r = 0.71; P < 0.05), implying frontal lobe dysfunction. These correlations suggest that a reduced NAA/Cr ratio is a marker of cortical neuronal loss and dysfunction in ALS. (orig.)

  8. The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

    Directory of Open Access Journals (Sweden)

    Stefan eHeim

    2012-12-01

    Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

  9. MRI in patients with temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Kodama, Kazuhiro

    1992-01-01

    The present study investigated magnetic resonance imaging (MRI) features in temporal lobe epilepsy and correlated them with clinical variables, such as age, illness duration, past history, and the frequency of seizure. Cerebral MRI was performed in 45 patients with temporal lobe epilepsy of unknown etiology, using a 0.5 T and/or a 1.5 T MRI systems. The temporal lobe was seen as high signal intensity on T2-weighted images and/or proton density-weighted images in 6 patients, although it was missed on CT and T1-weighted images. The high intensity area seemed to reflect sclerosis of the temporal lobe. This finding was significantly associated with partial seizure. Of these patients, 3 had a history of febrile convulsions. Ten patients had slight dilatation of the inferior horn of the lateral ventricle. They were significantly old at the time of onset and examination, as compared with those without dilatation. Furthermore, 6 patients with unilateral dilatation were significantly younger than the other 4 with bilateral dilatation. Nine patients had small multiple high signal areas in white matter, mainly in the parietal lobe, which suggested vascular origin. These patients were significantly old at the time of onset and examination, as compared with those having no such findings. In depicting high signal intensity areas, a 1.5 T MRI system was not always superior to a 0.5 T MRI system. Proton density-weighted images were better than T2-weighted images in some patients. (N.K.)

  10. OCCIPITAL LOBE SYNDROME

    OpenAIRE

    Shahdevi Nandar Kurniawan

    2016-01-01

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

  11. Significance of the Tentorial Alignment in Protecting the Occipital Lobe with the Poppen Approach for Tentorial or Pineal Area Meningiomas.

    Science.gov (United States)

    Li, Deling; Zhang, Haoyu; Jia, Wang; Zhang, Liwei; Zhang, Junting; Liu, Weiming; Ni, Ming; Jia, Guijun

    2017-12-01

    We aimed to identify the factors that can predict the risk of occipital lobe damage preoperatively when resecting tumors located at the tentorial or pineal regions with the occipital-transtentorial approach (Poppen approach). In 27 consecutive patients who underwent tumor resection with the Poppen approach for tentorial or pineal region meningiomas, the following morphologic parameters were assessed on a preoperative magnetic resonance imaging: (1) tentorial angle, (2) tentorial length, and (3) the shortest distance from the confluence of the sinus to the tumor. These parameters, together with tumor size, texture, and resection extent, were correlated with occipital lobe damage by using the one-way analysis of variance, χ 2 , or Fisher's exact tests. The mean value was 55.3° ± 5.6° (range, 45°-66°) for the tentorial angle, which was significantly associated with the occipital lobe damage grades (P = 0.008), but this was not the case for the tentorial length (P = 0.802) and the shortest distance from the confluence of the sinus to the tumor (P = 0.695). Interestingly, age was also strongly associated with occipital lobe damage risk (P = 0.020). The patients in the subgroup with no occipital damage (grade 4) were the youngest (aged 47.3 years), compared with other grades, with age of 58.0 years for grade 1, 54.3 years for grade 2, and 58.6 years for grade 3. These 2 parameters were also significant after multivariate analysis. No correlation was observed between either tumor nature or the extent of resection and damage grades. The risk of occipital lobe damage increases in the presence of a steep tentorial angle during the Poppen approach for tentorial or pineal area tumors. Awareness of such anatomic features preoperatively is important for minimizing operative complications. Copyright © 2017. Published by Elsevier Inc.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  13. Damage to Broca’s area OR the anterior temporal lobe is implicated in stroke-induced agrammatic comprehension: it depends on the task

    Directory of Open Access Journals (Sweden)

    Corianne Rogalsky

    2015-04-01

    Full Text Available The neurobiology of sentence comprehension remains unresolved. Previous large-scale studies of stroke patients have yielded conflicting results regarding sentence comprehension, implicating inferior frontal, anterior temporal and/or posterior temporal regions (Dronkers et al., 2004; Magnusdottir et al., 2013; Thothathiri et al. 2012. Furthermore, only one large-scale lesion study (Magnusdottir et al. 2013 has examined the neural underpinnings of agrammatic comprehension (i.e. substantially worse performance on sentences with noncanonical word orders compared to canonical word order sentences in English, a hallmark of Broca’s aphasia. This one previous study of noncanonical < canonical sentence performance on a sentence picture-matching task implicated damage to the left anterior temporal lobe (ATL and to a lesser degree Broca’s area damage (i.e. < 10% of significant voxels (Magnusdottir et al. 2013. The present study investigated the neurobiology of agrammatic comprehension with two sentence comprehension tasks in the MARC test battery: a sentence-picture matching task (the SOAP Test: a test of syntactic complexity; Love & Oster, 2002 and a sentence plausibility judgment task. Each task contained active, passive, subject-relative and object-relative sentences. Participants included 91 patients with chronic focal cerebral damage. First, we conducted voxel-based lesion symptom mapping (VLSM; Bates et al. 2003 for each sentence type in each task. Consistent with previous studies (Magnusdottir et al. 2013; Thothathiri et al. 2012, the VLSMs identified a significant association between sentence comprehension impairments and damage to a large left temporal-inferior parietal network for all sentences (peak t values were in posterior temporal and inferior parietal voxels; no areas of frontal lobe damage were significant for any sentence type/task. We then conducted VLSMs to identify areas of damage associated specifically with agrammatic

  14. Frontal lobe atrophy in motor neuron diseases.

    Science.gov (United States)

    Kiernan, J A; Hudson, A J

    1994-08-01

    Neuronal degeneration in the precentral gyrus alone cannot account for the occurrence of spastic paresis in motor neuron diseases. To look for more extensive cortical atrophy we measured MRIs of the upper parts of the frontal and parietal lobes in 11 sporadic cases of classical amyotrophic lateral sclerosis (ALS), eight patients with primary lateral sclerosis (PLS) and an age- and sex-matched group of 49 neurologically normal people. None of the patients had overt dementia or other mental diseases. In PLS there is progressive spastic paresis but in contrast to ALS there is no lower motor neuron degeneration. The surface area of the precentral gyri and the amount of underlying white matter in PLS were consistently approximately 75% of the normal size. By contrast, there was some shrinkage of the precentral gyri in some of the ALS patients but the mean measurements for the group did not differ significantly from the controls. Anterior to the precentral sulci, the cortical surface area in PLS was approximately 85% of that of the controls, with correspondingly reduced white matter. In ALS the cortical surface areas of the anterior frontal lobes did not differ from those of the controls, but the amount of underlying white matter was reduced almost as much in ALS as it was in PLS. The measured changes in the frontal lobes suggest that in PLS there is simultaneous atrophy of the primary, premotor and supplementary motor areas of the cortex, with consequent degeneration of corticospinal and corticoreticular axons descending through the underlying white matter. These changes could account for the progressive upper motor neuron syndrome. In ALS, with no significant frontal cortical atrophy, the shrinkage of the white matter may be due to degeneration of axons projecting to the frontal cortex from elsewhere. Deprivation of afferents could explain the diminution of motor functions of the frontal lobes in ALS and also the changes in word fluency, judgement and attention that

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

    Science.gov (United States)

    Berlucchi, Giovanni

    2014-07-01

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

  16. Right parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor.

    Science.gov (United States)

    Della Puppa, Alessandro; De Pellegrin, Serena; d'Avella, Elena; Gioffrè, Giorgio; Munari, Marina; Saladini, Marina; Salillas, Elena; Scienza, Renato; Semenza, Carlo

    2013-11-01

    The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. Calculation mapping in awake surgery was performed in 3 right-handed patients affected by high-grade gliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits. In all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in single-digit multiplication and addition calculations were mapped using bipolar electrostimulation. In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected as being specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionally specific for multiplication. No functional sites for language were detected. All sites functional for calculation were spared during tumor resection, which was complete in all cases without postoperative neurological deficits. These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.

  17. Activations in temporal areas using visual and auditory naming stimuli: A language fMRI study in temporal lobe epilepsy.

    Science.gov (United States)

    Gonzálvez, Gloria G; Trimmel, Karin; Haag, Anja; van Graan, Louis A; Koepp, Matthias J; Thompson, Pamela J; Duncan, John S

    2016-12-01

    Verbal fluency functional MRI (fMRI) is used for predicting language deficits after anterior temporal lobe resection (ATLR) for temporal lobe epilepsy (TLE), but primarily engages frontal lobe areas. In this observational study we investigated fMRI paradigms using visual and auditory stimuli, which predominately involve language areas resected during ATLR. Twenty-three controls and 33 patients (20 left (LTLE), 13 right (RTLE)) were assessed using three fMRI paradigms: verbal fluency, auditory naming with a contrast of auditory reversed speech; picture naming with a contrast of scrambled pictures and blurred faces. Group analysis showed bilateral temporal activations for auditory naming and picture naming. Correcting for auditory and visual input (by subtracting activations resulting from auditory reversed speech and blurred pictures/scrambled faces respectively) resulted in left-lateralised activations for patients and controls, which was more pronounced for LTLE compared to RTLE patients. Individual subject activations at a threshold of T>2.5, extent >10 voxels, showed that verbal fluency activated predominantly the left inferior frontal gyrus (IFG) in 90% of LTLE, 92% of RTLE, and 65% of controls, compared to right IFG activations in only 15% of LTLE and RTLE and 26% of controls. Middle temporal (MTG) or superior temporal gyrus (STG) activations were seen on the left in 30% of LTLE, 23% of RTLE, and 52% of controls, and on the right in 15% of LTLE, 15% of RTLE, and 35% of controls. Auditory naming activated temporal areas more frequently than did verbal fluency (LTLE: 93%/73%; RTLE: 92%/58%; controls: 82%/70% (left/right)). Controlling for auditory input resulted in predominantly left-sided temporal activations. Picture naming resulted in temporal lobe activations less frequently than did auditory naming (LTLE 65%/55%; RTLE 53%/46%; controls 52%/35% (left/right)). Controlling for visual input had left-lateralising effects. Auditory and picture naming activated

  18. Visual Categorization and the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Jamie K Fitzgerald

    2012-05-01

    Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

  19. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

    Science.gov (United States)

    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  20. Unique and shared areas of cognitive function in children with intractable frontal or temporal lobe epilepsy.

    Science.gov (United States)

    Law, Nicole; Widjaja, Elysa; Smith, Mary Lou

    2018-03-01

    Previous findings have been mixed in terms of identifying a distinct pattern of neuropsychological deficits in children with frontal lobe epilepsy (FLE) and in those with temporal lobe epilepsy (TLE). The current study investigated the neuropsychological similarities and differences across these two pediatric medically intractable localization-related epilepsies. Thirty-eight children with FLE, 20 children with TLE, and 40 healthy children (HC) participated in this study. A comprehensive battery of standardized tests assessed five neuropsychological domains including intelligence, language, memory, executive function, and motor function. A principal component analysis (PCA) was used to distill our neuropsychological measures into latent components to compare between groups. Principal component analysis extracted 5 latent components: executive function (F1), verbal semantics (F2), motor (F3), nonverbal cognition/impulsivity (F4), and verbal cognition/attention (F5). The group with FLE differed from the HC group on F1, F2, F4, and F5, and had worse performance than the group with TLE on F1; the group with TLE had lower performance relative to the HC group on F2. Our findings suggest that, in comparison with neurotypically developing children, children with medically intractable FLE have more widespread neuropsychological impairments than do children with TLE. The differences between the two patient groups were greatest for the factor score most clearly related to executive function. The results provide mixed support for the concept of specificity in neuropsychological dysfunction among different subtypes of localization-related medically intractable childhood epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. [Successive subcortical hemorrhages in the superior parietal lobule and postcentral gyrus in a 23-year-old female].

    Science.gov (United States)

    Sato, K; Yoshikawa, H; Komai, K; Takamori, M

    1998-04-01

    We report a non-hypertensive 23-year-old female with successive hemorrhages in parietal subcortical regions. She had first experienced a transient pain in the left upper extremity one month before admission. She noticed dysesthesia in the same limb and weakness on her left hand, and, five days after, visited our hospital because of suddenly developed convulsion in the limb and loss of consciousness for a few minutes. Neurological examination revealed distal dominant flaccid paresis, positive pathological reflex and touch and position sense disturbances in the affected limb. Brain CT detected two high-density areas in the parietal lobe. Brain MRI demonstrated an acute phase subcortical hematoma in the left postcentral gyrus and a subacute phase one in the left superior parietal lobule. SPECT indicated hypoperfusion in the left frontal and parietal cortex. Cerebral angiography showed no abnormal findings. Her symptoms gradually improved, but left ulnar-type pseudoradicular sensory impairment remained on discharge. We considered the hemorrhage in this patient have arisen from rupture of cavernous hemangioma, because she was relatively young, the hematomas were oval in shape and successively developed in the left parietal lobe. Our patient suggests that a subcortical hemorrhage in the post-central gyrus causes flaccid paresis and pyramidal tract involvement.

  2. The extratemporal lobe epilepsies in the epilepsy monitoring unit

    Science.gov (United States)

    Dash, Deepa; Tripathi, Manjari

    2014-01-01

    Extratemporal lobe epilepsies (ETLE) are characterized by the epileptogenic foci outside the temporal lobe. They have a wide spectrum of semiological presentation depending upon the site of origin. They can arise from frontal, parietal, occipital lobes and from hypothalamic hamartoma. We discuss in this review the semiology of different types of ETLE encountered in the epilepsy monitoring unit. PMID:24791090

  3. Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

    Science.gov (United States)

    Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

    2014-10-15

    This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Uncertain relational reasoning in the parietal cortex.

    Science.gov (United States)

    Ragni, Marco; Franzmeier, Imke; Maier, Simon; Knauff, Markus

    2016-04-01

    The psychology of reasoning is currently transitioning from the study of deductive inferences under certainty to inferences that have degrees of uncertainty in both their premises and conclusions; however, only a few studies have explored the cortical basis of uncertain reasoning. Using transcranial magnetic stimulation (TMS), we show that areas in the right superior parietal lobe (rSPL) are necessary for solving spatial relational reasoning problems under conditions of uncertainty. Twenty-four participants had to decide whether a single presented order of objects agreed with a given set of indeterminate premises that could be interpreted in more than one way. During the presentation of the order, 10-Hz TMS was applied over the rSPL or a sham control site. Right SPL TMS during the inference phase disrupted performance in uncertain relational reasoning. Moreover, we found differences in the error rates between preferred mental models, alternative models, and inconsistent models. Our results suggest that different mechanisms are involved when people reason spatially and evaluate different kinds of uncertain conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. The fMRI study on the front-parietal activation in abacus mental calculation trained children

    International Nuclear Information System (INIS)

    Zhao Kunyuan; Wang Bin; Long Jinfeng; Li Lixin; Shen Xiaojun

    2010-01-01

    Objective: To investigate the difference in front-parietal activation between the trained and untrained children engaged in addition and multiplication with functional magnetic resonance imaging (fMRI), and to explore the role of abacus mental calculation in brain development. Methods: Twenty-four children trained with abacus mental calculation and twelve untrained children performed mental calculation tasks including addition, multiplication and number-object control judging tasks. Blood oxygenation level dependence (BOLD) fMRI was performed when they were calculating. All data were analyzed by SPM2 (statistical parametric mapping 2) to generate the brain activation map. Results: The performance of the trained group had better correctness and shorter reaction time than that of the untrained group. The front-parietal activation between two groups had obvious difference. The activation involved less prefrontal cortex in the trained group than in the untrained group (P<0.05). The parietal activation in the trained group was mainly in the posterior superior parietal lobe/ precuneus, whereas the activation areas focused on the inferior parietal lobule in the untrained group. Conclusion: Abacus mental calculation involves multiple functional areas. and these areas may work together as a whole in processing arithmetic problems. Abacus mental calculation not only enhances the information processing in some brain areas and improves the utilization efficiency of neural resources, but also plays an important role in developing brain. (authors)

  6. Predicting the Permanent Safe Donor Area for Hair Transplantation in Koreans with Male Pattern Baldness according to the Position of the Parietal Whorl

    Science.gov (United States)

    Na, Young Cheon; Moh, Jae Seong; Lee, Seung Yong; You, Seung Hyun

    2014-01-01

    Background The most crucial factor in hair transplantation for male pattern baldness (MPB) patients is the efficient utilization of the donor-recipient ratio. However, there is no known factor that scientifically predicts the rate of progression of alopecia or indicates a permanently safe donor area. Methods The study considered 1,008 Korean adult males with MPB; of these, it excluded 56 males with an absence of parietal whorls (PWs). The authors investigated the distance from the vertical bimeatal line (VM) to the PW, from the PW to the upper border of the helical rim (HR), and the distance from the PW to the occipital fringe (OF) in 952 subjects with a PW. Furthermore, we examined the distance from the PW to the OF considering the duration of alopecia and age in 322 subjects with vertex alopecia. Results The distance between the VM and PW varied from 1.5 to 11 cm, with an average distance of 6.25 cm. The PW-HR distance ranged from 3.4 to 17.5 cm, and the average distance was 7.79 cm. The PW-OF distance ranged from 0.5 to 5.5 cm, and the average distance was 2.37 cm. Conclusions For the PW, very large variations existed in the vertical direction. The position of the PW could predict the progression range of the total alopecia of the vertex. Alopecia mostly progresses within 6 cm of the PW toward the occipital side. PMID:24883280

  7. Predicting the Permanent Safe Donor Area for Hair Transplantation in Koreans with Male Pattern Baldness according to the Position of the Parietal Whorl

    Directory of Open Access Journals (Sweden)

    Jae Hyun Park

    2014-05-01

    Full Text Available Background The most crucial factor in hair transplantation for male pattern baldness (MPB patients is the efficient utilization of the donor-recipient ratio. However, there is no known factor that scientifically predicts the rate of progression of alopecia or indicates a permanently safe donor area. Methods The study considered 1,008 Korean adult males with MPB; of these, it excluded 56 males with an absence of parietal whorls (PWs. The authors investigated the distance from the vertical bimeatal line (VM to the PW, from the PW to the upper border of the helical rim (HR, and the distance from the PW to the occipital fringe (OF in 952 subjects with a PW. Furthermore, we examined the distance from the PW to the OF considering the duration of alopecia and age in 322 subjects with vertex alopecia. Results The distance between the VM and PW varied from 1.5 to 11 cm, with an average distance of 6.25 cm. The PW-HR distance ranged from 3.4 to 17.5 cm, and the average distance was 7.79 cm. The PW-OF distance ranged from 0.5 to 5.5 cm, and the average distance was 2.37 cm. Conclusions For the PW, very large variations existed in the vertical direction. The position of the PW could predict the progression range of the total alopecia of the vertex. Alopecia mostly progresses within 6 cm of the PW toward the occipital side.

  8. Brain stimulation used as biofeedback in neuronal activation of the temporal lobe area in autistic children

    Directory of Open Access Journals (Sweden)

    Vernon Furtado da Silva

    2016-08-01

    Full Text Available ABSTRACT This study focused upon the functional capacity of mirror neurons in autistic children. 30 individuals, 10 carriers of the autistic syndrome (GCA, 10 with intellectual impairments (GDI, and 10 non-autistics (GCN had registered eletroencephalogram from the brain area theoretically related to mirror neurons. Data collection procedure occurred prior to brain stimulation and after the stimulation session. During the second session, participants had to alternately process figures evoking neutral, happy, and/or sorrowful feelings. Results proved that, for all groups, the stimulation process in fact produced additional activation in the neural area under study. The level of activation was related to the format of emotional stimuli and the likelihood of boosting such stimuli. Since the increase of activation occurred in a model similar to the one observed for the control group, we may suggest that the difficulty people with autism have at expressing emotions is not due to nonexistence of mirror neurons.

  9. Brain stimulation used as biofeedback in neuronal activation of the temporal lobe area in autistic children.

    Science.gov (United States)

    Silva, Vernon Furtado da; Calomeni, Mauricio Rocha; Nunes, Rodolfo Alkmim Moreira; Pimentel, Carlos Elias; Martins, Gabriela Paes; Oliveira, Patrícia da Cruz Araruna; Silva, Patrícia Bagno; Silva, Alair Pedro Ribeiro de Souza E

    2016-08-01

    This study focused upon the functional capacity of mirror neurons in autistic children. 30 individuals, 10 carriers of the autistic syndrome (GCA), 10 with intellectual impairments (GDI), and 10 non-autistics (GCN) had registered eletroencephalogram from the brain area theoretically related to mirror neurons. Data collection procedure occurred prior to brain stimulation and after the stimulation session. During the second session, participants had to alternately process figures evoking neutral, happy, and/or sorrowful feelings. Results proved that, for all groups, the stimulation process in fact produced additional activation in the neural area under study. The level of activation was related to the format of emotional stimuli and the likelihood of boosting such stimuli. Since the increase of activation occurred in a model similar to the one observed for the control group, we may suggest that the difficulty people with autism have at expressing emotions is not due to nonexistence of mirror neurons.

  10. Non-primary motor areas in the human frontal lobe are connected directly to hand muscles.

    Science.gov (United States)

    Teitti, S; Määttä, S; Säisänen, L; Könönen, M; Vanninen, R; Hannula, H; Mervaala, E; Karhu, J

    2008-04-15

    Structural studies in primates have shown that, in addition to the primary motor cortex (M1), premotor areas are a source of corticospinal tracts. The function of these putative corticospinal neuronal tracts in humans is still unclear. We found frontal non-primary motor areas (NPMAs), which react to targeted non-invasive magnetic pulses and activate peripheral muscles as fast as or even faster than those in M1. Hand muscle movements were observed in all our subjects about 20 ms after transcranial stimulation of the superior frontal gyrus (Brodmann areas 6 and 8). Stimulation of NPMA could activate both proximal and distal upper limb muscles with the same delay as a stimulation of the M1, indicating converging motor representations with direct functional connections to the hand. We suggest that these non-primary cortical motor representations provide additional capacity for the fast execution of movements. Such a capacity may play a role in motor learning and in recovery from motor deficits.

  11. Acupuncture at Waiguan (SJ5) and sham points influences activation of functional brain areas of ischemic stroke patients: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Qi, Ji; Chen, Junqi; Huang, Yong; Lai, Xinsheng; Tang, Chunzhi; Yang, Junjun; Chen, Hua; Qu, Shanshan

    2014-02-01

    Most studies addressing the specificity of meridians and acupuncture points have focused mainly on the different neural effects of acupuncture at different points in healthy individuals. This study examined the effects of acupuncture on brain function in a pathological context. Sixteen patients with ischemic stroke were randomly assigned to true point group (true acupuncture at right Waiguan (SJ5)) and sham point group (sham acupuncture). Results of functional magnetic resonance imaging revealed activation in right parietal lobe (Brodmann areas 7 and 19), the right temporal lobe (Brodmann area 39), the right limbic lobe (Brodmann area 23) and bilateral occipital lobes (Brodmann area 18). Furthermore, inhibition of bilateral frontal lobes (Brodmann area 4, 6, and 45), right parietal lobe (Brodmann areas 1 and 5) and left temporal lobe (Brodmann area 21) were observed in the true point group. Activation in the precuneus of right parietal lobe (Brodmann area 7) and inhibition of the left superior frontal gyrus (Brodmann area 10) was observed in the sham group. Compared with sham acupuncture, acupuncture at Waiguan in stroke patients inhibited Brodmann area 5 on the healthy side. Results indicated that the altered specificity of sensation-associated cortex (Brodmann area 5) is possibly associated with a central mechanism of acupuncture at Waiguan for stroke patients.

  12. Effect of Panax notoginseng saponins on the expression of beta-amyloid protein in the cortex of the parietal lobe and hippocampus, and spatial learning and memory in a mouse model of senile dementia

    Institute of Scientific and Technical Information of China (English)

    Zhenguo Zhong; Dengpan Wu; Liang Lü; Jinsheng Wang; Wenyan Zhang; Zeqiang Qu

    2008-01-01

    immunohistochemistry. The mRNA content of App, tau, acetylcholinesterase, and synaptophysin (Syp) was tested by real time PCR and RT-PCR.RESULTS: The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group (P < 0.05). The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β1-40,A β1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group (P < 0.05).CONCLUSION: These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer's disease. The therapeutic effects of PNS for Alzheimer's disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.

  13. Examining the role of the temporo-parietal network in memory, imagery and viewpoint transformations

    Directory of Open Access Journals (Sweden)

    Kiret eDhindsa

    2014-09-01

    Full Text Available The traditional view of the medial temporal lobe (MTL focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g. O’Keefe (1976; Ekstrom et al. (2003; King et al. (2002. According to our BBB model (Byrne et al. (2007, these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal ’window’. Such imagery is necessarily egocentric and forms part of visuospatial working memory, where it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al. (2012; Zhang et al. (2012 supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object 1 from visuospatial working memory (we assume working memory due to the order of tasks and the consistency viewpoint, but long-term memory is also possible, 2 after a rotation of viewpoint, or 3 after a rotation and translation (judgement of relative direction. We found performance-related activity in both tasks requiring viewpoint rotation in the core medial temporal to medial parietal. These results are consistent with the BBB model and shed further light on the mechanisms underlying spatial memory, mental imagery and viewpoint

  14. Medical image of the week: azygous lobe

    Directory of Open Access Journals (Sweden)

    Bhupinder Natt

    2013-12-01

    Full Text Available No abstract available. Article truncated at 150 words. A 59 year old man underwent chest radiography for evaluation of fever and cough. Imaging showed an accessory azygous lobe. An azygos lobe is found in 1% of anatomic specimens and forms when the right posterior cardinal vein, one of the precursors of the azygos vein, fails to migrate over the apex of the lung (1. Instead, the vein penetrates the lung carrying along pleural layers that entrap a portion of the right upper lobe. The vein appears to run within the lung, but is actually surrounded by both parietal and visceral pleura. The azygos fissure therefore consists of four layers of pleura, two parietal layers and two visceral layers, which wrap around the vein giving the appearance of a tadpole. Apart from an interesting incidental radiological finding, it is of limited clinical importance except that its presence should be recognized during thoracoscopic procedures. This patient was found to have …

  15. Brain SPECT imaging in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Krausz, Y.; Yaffe, S.; Atlan, H.; Cohen, D.; Konstantini, S.; Meiner, Z.

    1991-01-01

    Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using 99m Tc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed. (orig.)

  16. Development of parietal bone surrogates for parietal graft lift training

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    Hollensteiner Marianne

    2016-09-01

    Full Text Available Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone thus being suitable for tabula externa graft lift training.

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

    Science.gov (United States)

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

    2015-05-01

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

  18. Microsurgical anatomy of the central lobe.

    Science.gov (United States)

    Frigeri, Thomas; Paglioli, Eliseu; de Oliveira, Evandro; Rhoton, Albert L

    2015-03-01

    The central lobe consists of the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface and corresponds to the sensorimotor cortex. The objective of the present study was to define the neural features, craniometric relationships, arterial supply, and venous drainage of the central lobe. Cadaveric hemispheres dissected using microsurgical techniques provided the material for this study. The coronal suture is closer to the precentral gyrus and central sulcus at its lower rather than at its upper end, but they are closest at a point near where the superior temporal line crosses the coronal suture. The arterial supply of the lower two-thirds of the lateral surface of the central lobe was from the central, precentral, and anterior parietal branches that arose predominantly from the superior trunk of the middle cerebral artery. The medial surface and the superior third of the lateral surface were supplied by the posterior interior frontal, paracentral, and superior parietal branches of the pericallosal and callosomarginal arteries. The venous drainage of the superior two-thirds of the lateral surface and the central lobe on the medial surface was predominantly through the superior sagittal sinus, and the inferior third of the lateral surface was predominantly through the superficial sylvian veins to the sphenoparietal sinus or the vein of Labbé to the transverse sinus. The pre- and postcentral gyri and paracentral lobule have a morphological and functional anatomy that differentiates them from the remainder of their respective lobes and are considered by many as a single lobe. An understanding of the anatomical relationships of the central lobe can be useful in preoperative planning and in establishing reliable intraoperative landmarks.

  19. Examining the role of the temporo-parietal network in memory, imagery, and viewpoint transformations.

    Science.gov (United States)

    Dhindsa, Kiret; Drobinin, Vladislav; King, John; Hall, Geoffrey B; Burgess, Neil; Becker, Suzanna

    2014-01-01

    The traditional view of the medial temporal lobe (MTL) focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g., O'Keefe, 1976; King et al., 2002; Ekstrom et al., 2003). According to our BBB model (Byrne et al., 2007), these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal "window." Such imagery is necessarily egocentric and forms part of visuospatial working memory, in which it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al., 2012; Zhang et al., 2012) supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object (1) from visuospatial working memory (we assume transient working memory due to the order of tasks and the absence of change in viewpoint, but long-term memory retrieval is also possible), (2) after a rotation of viewpoint, or (3) after a rotation and translation of viewpoint (judgment of relative direction). We found performance-related activity in both tasks requiring viewpoint rotation (ROT and JRD, i.e., conditions 2 and 3) in the core medial temporal to medial parietal circuit identified by the BBB model. These results are consistent with the

  20. Predicting oculomotor behaviour from correlated populations of posterior parietal neurons.

    Science.gov (United States)

    Graf, Arnulf B A; Andersen, Richard A

    2015-01-23

    Oculomotor function critically depends on how signals representing saccade direction and eye position are combined across neurons in the lateral intraparietal (LIP) area of the posterior parietal cortex. Here we show that populations of parietal neurons exhibit correlated variability, and that using these interneuronal correlations yields oculomotor predictions that are more accurate and also less uncertain. The structure of LIP population responses is therefore essential for reliable read-out of oculomotor behaviour.

  1. Frontal Lobe Seizures

    Science.gov (United States)

    ... cause of frontal lobe epilepsy remains unknown. Complications Status epilepticus. Frontal lobe seizures tend to occur in clusters and may provoke a dangerous condition called status epilepticus — in which seizure activity lasts much longer than ...

  2. A Curious Lobe

    Directory of Open Access Journals (Sweden)

    Andréa Chabot-Naud

    2011-01-01

    Full Text Available A case of azygos lobe is presented. An azygos lobe is an accessory lobe of the lung that may occasionally be confused with a pathological process such as a bulla, lung abscess or neoplasm. Its pathogenesis is discussed, as are the characteristic x-ray features that enable an accurate diagnosis.

  3. Parietal lesion effects on cued recall following pair associate learning.

    Science.gov (United States)

    Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

    2015-07-01

    We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. 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.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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 Soft-ware (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. (author)

  6. Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

    Science.gov (United States)

    Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

    2018-06-01

    Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

  7. Nuclear Glycogen Inclusions in Canine Parietal Cells.

    Science.gov (United States)

    Silvestri, S; Lepri, E; Dall'Aglio, C; Marchesi, M C; Vitellozzi, G

    2017-05-01

    Nuclear glycogen inclusions occur infrequently in pathologic conditions but also in normal human and animal tissues. Their function or significance is unclear. To the best of the authors' knowledge, no reports of nuclear glycogen inclusions in canine parietal cells exist. After initial observations of nuclear inclusions/pseudoinclusions during routine histopathology, the authors retrospectively examined samples of gastric mucosa from dogs presenting with gastrointestinal signs for the presence of intranuclear inclusions/pseudoinclusions and determined their composition using histologic and electron-microscopic methods. In 24 of 108 cases (22%), the authors observed various numbers of intranuclear inclusions/pseudoinclusions within scattered parietal cells. Nuclei were characterized by marked karyomegaly and chromatin margination around a central optically empty or slightly eosinophilic area. The intranuclear inclusions/pseudoinclusions stained positive with periodic acid-Schiff (PAS) and were diastase sensitive, consistent with glycogen. Several PAS-positive/diastase-sensitive sections were further examined by transmission electron microscopy, also using periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining to identify polysaccharides. Ultrastructurally, the nuclear inclusions were composed of electron-dense particles that were not membrane bound, without evidence of nuclear membrane invaginations or cytoplasmic organelles in the nuclei, and positive staining with PA-TCH-SP, confirming a glycogen composition. No cytoplasmic glycogen deposits were observed, suggesting that the intranuclear glycogen inclusions were probably synthesized in loco. Nuclear glycogen inclusions were not associated with gastritis or colonization by Helicobacter-like organisms ( P > .05). Our findings suggest that nuclear glycogen inclusions in canine parietal cells could be an incidental finding. Nevertheless, since nuclear glycogen is present in several pathologic

  8. Frontal lobe function in temporal lobe epilepsy

    Science.gov (United States)

    Stretton, J.; Thompson, P.J.

    2012-01-01

    Summary Temporal lobe epilepsy (TLE) is typically associated with long-term memory dysfunction. The frontal lobes support high-level cognition comprising executive skills and working memory that is vital for daily life functioning. Deficits in these functions have been increasingly reported in TLE. Evidence from both the neuropsychological and neuroimaging literature suggests both executive function and working memory are compromised in the presence of TLE. In relation to executive impairment, particular focus has been paid to set shifting as measured by the Wisconsin Card Sorting Task. Other discrete executive functions such as decision-making and theory of mind also appear vulnerable but have received little attention. With regard to working memory, the medial temporal lobe structures appear have a more critical role, but with emerging evidence of hippocampal dependent and independent processes. The relative role of underlying pathology and seizure spread is likely to have considerable bearing upon the cognitive phenotype and trajectory in TLE. The identification of the nature of frontal lobe dysfunction in TLE thus has important clinical implications for prognosis and surgical management. Longitudinal neuropsychological and neuroimaging studies assessing frontal lobe function in TLE patients pre- and postoperatively will improve our understanding further. PMID:22100147

  9. Emphysema lung lobe volume reduction: effects on the ipsilateral and contralateral lobes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Matthew S.; Kim, Hyun J.; Abtin, Fereidoun G.; Galperin-Aizenberg, Maya; Pais, Richard; Da Costa, Irene G.; Ordookhani, Arash; Chong, Daniel; Ni, Chiayi; McNitt-Gray, Michael F.; Goldin, Jonathan G. [David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, CA (United States); Strange, Charlie [Medical University of South Carolina, Department of Pulmonary and Critical Care Medicine, Columbia, SC (United States); Tashkin, Donald P. [David Geffen School of Medicine at UCLA, Division of Pulmonary and Critical Care Medicine, Los Angeles, CA (United States)

    2012-07-15

    To investigate volumetric and density changes in the ipsilateral and contralateral lobes following volume reduction of an emphysematous target lobe. The study included 289 subjects with heterogeneous emphysema, who underwent bronchoscopic volume reduction of the most diseased lobe with endobronchial valves and 132 untreated controls. Lobar volume and low-attenuation relative area (RA) changes post-procedure were measured from computed tomography images. Regression analysis (Spearman's rho) was performed to test the association between change in the target lobe volume and changes in volume and density variables in the other lobes. The target lobe volume at full inspiration in the treatment group had a mean reduction of -0.45 L (SE = 0.034, P < 0.0001), and was associated with volume increases in the ipsilateral lobe (rho = -0.68, P < 0.0001) and contralateral lung (rho = -0.16, P = 0.006), and overall reductions in expiratory RA (rho = 0.31, P < 0.0001) and residual volume (RV)/total lung capacity (TLC) (rho = 0.13, P = 0.03). When the volume of an emphysematous target lobe is reduced, the volume is redistributed primarily to the ipsilateral lobe, with an overall reduction. Image-based changes in lobar volumes and densities indicate that target lobe volume reduction is associated with statistically significant overall reductions in air trapping, consistent with expansion of the healthier lung. (orig.)

  10. Emphysema lung lobe volume reduction: effects on the ipsilateral and contralateral lobes

    International Nuclear Information System (INIS)

    Brown, Matthew S.; Kim, Hyun J.; Abtin, Fereidoun G.; Galperin-Aizenberg, Maya; Pais, Richard; Da Costa, Irene G.; Ordookhani, Arash; Chong, Daniel; Ni, Chiayi; McNitt-Gray, Michael F.; Goldin, Jonathan G.; Strange, Charlie; Tashkin, Donald P.

    2012-01-01

    To investigate volumetric and density changes in the ipsilateral and contralateral lobes following volume reduction of an emphysematous target lobe. The study included 289 subjects with heterogeneous emphysema, who underwent bronchoscopic volume reduction of the most diseased lobe with endobronchial valves and 132 untreated controls. Lobar volume and low-attenuation relative area (RA) changes post-procedure were measured from computed tomography images. Regression analysis (Spearman's rho) was performed to test the association between change in the target lobe volume and changes in volume and density variables in the other lobes. The target lobe volume at full inspiration in the treatment group had a mean reduction of -0.45 L (SE = 0.034, P < 0.0001), and was associated with volume increases in the ipsilateral lobe (rho = -0.68, P < 0.0001) and contralateral lung (rho = -0.16, P = 0.006), and overall reductions in expiratory RA (rho = 0.31, P < 0.0001) and residual volume (RV)/total lung capacity (TLC) (rho = 0.13, P = 0.03). When the volume of an emphysematous target lobe is reduced, the volume is redistributed primarily to the ipsilateral lobe, with an overall reduction. Image-based changes in lobar volumes and densities indicate that target lobe volume reduction is associated with statistically significant overall reductions in air trapping, consistent with expansion of the healthier lung. (orig.)

  11. Bilateral front-parietal polymicrogyria accompanied by cobblestone lissencephaly: 3T MR imaging findings of a case

    International Nuclear Information System (INIS)

    Bozkurt, Y.; Battal, B.; Ozcan, E.; Kocaoglu, M.

    2012-01-01

    Full text: Background: The cerebral cortex develops in three overlapping stages: cell proliferation, neuronal migration, and cortical organization. Lissencephaly (smooth brain) is a severe malformation of the cerebral cortex that results from impaired neuronal migration. Polymicrogyria is a disorder of late migration or cortical organization, and supposed to reflect a disruption of normal neuronal migration with subsequent disordered cortical organization. A combination of cobblestone lissencephaly and polymicrogyria is very rare in the same patient's brain. Objective: To present clinical and 3T magnetic resonance (MR) imaging findings of a 17-year-old male with bilateral fronto-parietal polimicrogyria accompanied by cobblestone lissencaphaly. Materials and methods: A 17-year-old male who had seizures and involuntary muscular spasm from birth, was referred to our Hospital. The patient was evaluated by a complete history, physical examination, a laboratory work-up, and cranial MR examination for evaluate the central nervous system. Results: A sharp wave paroxysm in the left temporal area was observed in the electroencephalogram (EEG). The neurological examination of our patient was normal. A slight increase have seen in the aspartate aminotransferase (SGOT) levels. The other biochemical tests were found to be normal. Cranial MR imaging showed an irregular nodular cortex with hypomyelination of the white matter at the lateral and posterior part of the right occipital lobe. We also observed the changes compatible with polymicrogyria in a large area of the medial parts of the bilateral temporal and parietal lobes. Conclusion: The role of radiological modalities for diagnosis of cortical formation disorders are very important. MR imaging are fairly useful for evaluation of these anomalies

  12. Encefalomenigocele atrésico parietal Parietal atresic encephalomeningocele

    Directory of Open Access Journals (Sweden)

    Liliana Rivera Oliva

    2011-09-01

    Full Text Available El encefalocele es una anomalía congénita rara, en la que una porción del encéfalo protruye a través de un orificio craneal (evaginación, generalmente situado en la línea media. Clínicamente se caracteriza por una masa epicraneal, de consistencia blanda, muchas veces acompañada de trastornos psicomotores, convulsiones y trastornos de la visión. Se presenta el caso de un recién nacido con diagnóstico de encefalomeningocele atrésico parietal, intervenido quirúrgicamente y con evolución satisfactoria.The encephalocele is a uncommon congenital anomaly where a portion of encephalon protrudes through a cranial orifice (evagination, generally located in the middle line. Clinically, it is characterized by a soft epicranial mass often accompanied or psychomotor disorders, convulsions and vision disorders. This is the case of a newborn diagnosed with parietal atresic encephalomeningocele operated on with a satisfactory evolution.

  13. Investigation of Parietal Polysaccharides from Retama raetam Roots ...

    African Journals Online (AJOL)

    These results indicate the presence of the homogalacturonans and rhamnogalacturonans in pectin. This study constitutes the preliminary data obtained in the biochemical analysis of the parietal compounds of the roots of a species which grows in an arid area in comparison with those of its aerial parts. Keywords: Retama ...

  14. Alteration of functional connectivity within visuospatial working memory-related brain network in patients with right temporal lobe epilepsy: a resting-state fMRI study.

    Science.gov (United States)

    Lv, Zong-xia; Huang, Dong-Hong; Ye, Wei; Chen, Zi-rong; Huang, Wen-li; Zheng, Jin-ou

    2014-06-01

    This study aimed to investigate the resting-state brain network related to visuospatial working memory (VSWM) in patients with right temporal lobe epilepsy (rTLE). The functional mechanism underlying the cognitive impairment in VSWM was also determined. Fifteen patients with rTLE and 16 healthy controls matched for age, gender, and handedness underwent a 6-min resting-state functional MRI session and a neuropsychological test using VSWM_Nback. The VSWM-related brain network at rest was extracted using multiple independent component analysis; the spatial distribution and the functional connectivity (FC) parameters of the cerebral network were compared between groups. Behavioral data were subsequently correlated with the mean Z-value in voxels showing significant FC difference during intergroup comparison. The distribution of the VSWM-related resting-state network (RSN) in the group with rTLE was virtually consistent with that in the healthy controls. The distribution involved the dorsolateral prefrontal lobe and parietal lobe in the right hemisphere and the partial inferior parietal lobe and posterior lobe of the cerebellum in the left hemisphere (pright superior frontal lobe (BA8), right middle frontal lobe, and right ventromedial prefrontal lobe compared with the controls (pright superior frontal lobe (BA11), right superior parietal lobe, and left posterior lobe of the cerebellum (prights reserved.

  15. The frontal lobes and inhibitory function

    International Nuclear Information System (INIS)

    Konishi, Seiki

    2011-01-01

    Neuropsychological studies using traditional tasks of inhibitory functions, such as the Wisconsin card sorting test (WCST) and the Go/No-Go Task have revealed that the frontal lobe is responsible for several types of inhibitory functions. However, the detailed psychological nature of the inhibitory functions and the precise location of their critical foci within the frontal lobe remain to be investigated. Functional magnetic resonance imaging provides spatial and temporal resolution that allowed us to illuminate at least 4 frontal regions involved in inhibitory functions: the dorsolateral, ventrolateral, and rostral parts of the frontal lobe and the presupplementary motor area (preSMA). The ventrolateral part of the frontal lobe in the right hemisphere was activated during response inhibition. The preSMA in the left hemisphere was activated during inhibition of proactive interference immediately after the dimension changes of the WCST. The rostral part of the frontal lobe in the left hemisphere was activated during inhibition long after the dimension changes. The dorsolateral part of the frontal lobe in the left hemisphere was activated at the dimension changes in the first time, but not in the second time. These findings provide clues to our understanding of functional differentiation of inhibitory functions and their localization in the frontal lobe. (author)

  16. Temporal Lobe Epilepsy in Children

    Science.gov (United States)

    Nickels, Katherine C.; Wong-Kisiel, Lily C.; Moseley, Brian D.; Wirrell, Elaine C.

    2012-01-01

    The temporal lobe is a common focus for epilepsy. Temporal lobe epilepsy in infants and children differs from the relatively homogeneous syndrome seen in adults in several important clinical and pathological ways. Seizure semiology varies by age, and the ictal EEG pattern may be less clear cut than what is seen in adults. Additionally, the occurrence of intractable seizures in the developing brain may impact neurocognitive function remote from the temporal area. While many children will respond favorably to medical therapy, those with focal imaging abnormalities including cortical dysplasia, hippocampal sclerosis, or low-grade tumors are likely to be intractable. Expedient workup and surgical intervention in these medically intractable cases are needed to maximize long-term developmental outcome. PMID:22957247

  17. Temporal Lobe Seizure

    Science.gov (United States)

    ... functions, including having odd feelings — such as euphoria, deja vu or fear. Temporal lobe seizures are sometimes called ... sudden sense of unprovoked fear or joy A deja vu experience — a feeling that what's happening has happened ...

  18. Thalamotemporal impairment in temporal lobe epilepsy: a combined MRI analysis of structure, integrity, and connectivity.

    Science.gov (United States)

    Keller, Simon S; O'Muircheartaigh, Jonathan; Traynor, Catherine; Towgood, Karren; Barker, Gareth J; Richardson, Mark P

    2014-02-01

    Thalamic abnormality in temporal lobe epilepsy (TLE) is well known from imaging studies, but evidence is lacking regarding connectivity profiles of the thalamus and their involvement in the disease process. We used a novel multisequence magnetic resonance imaging (MRI) protocol to elucidate the relationship between mesial temporal and thalamic pathology in TLE. For 23 patients with TLE and 23 healthy controls, we performed T1 -weighted (for analysis of tissue structure), diffusion tensor imaging (tissue connectivity), and T1 and T2 relaxation (tissue integrity) MRI across the whole brain. We used connectivity-based segmentation to determine connectivity patterns of thalamus to ipsilateral cortical regions (occipital, parietal, prefrontal, postcentral, precentral, and temporal). We subsequently determined volumes, mean tractography streamlines, and mean T1 and T2 relaxometry values for each thalamic segment preferentially connecting to a given cortical region, and of the hippocampus and entorhinal cortex. As expected, patients had significant volume reduction and increased T2 relaxation time in ipsilateral hippocampus and entorhinal cortex. There was bilateral volume loss, mean streamline reduction, and T2 increase of the thalamic segment preferentially connected to temporal lobe, corresponding to anterior, dorsomedial, and pulvinar thalamic regions, with no evidence of significant change in any other thalamic segments. Left and right thalamotemporal segment volume and T2 were significantly correlated with volume and T2 of ipsilateral (epileptogenic), but not contralateral (nonepileptogenic), mesial temporal structures. These convergent and robust data indicate that thalamic abnormality in TLE is restricted to the area of the thalamus that is preferentially connected to the epileptogenic temporal lobe. The degree of thalamic pathology is related to the extent of mesial temporal lobe damage in TLE. © 2014 The Authors. Epilepsia published by Wiley Periodicals, Inc

  19. Parietal podocytes in normal human glomeruli.

    Science.gov (United States)

    Bariety, Jean; Mandet, Chantal; Hill, Gary S; Bruneval, Patrick

    2006-10-01

    Although parietal podocytes along the Bowman's capsule have been described by electron microscopy in the normal human kidney, their molecular composition remains unknown. Ten human normal kidneys that were removed for cancer were assessed for the presence and the extent of parietal podocytes along the Bowman's capsule. The expression of podocyte-specific proteins (podocalyxin, glomerular epithelial protein-1, podocin, nephrin, synaptopodin, and alpha-actinin-4), podocyte synthesized proteins (vascular endothelial growth factor and novH), transcription factors (WT1 and PAX2), cyclin-dependent kinase inhibitor p57, and intermediate filaments (cytokeratins and vimentin) was tested. In addition, six normal fetal kidneys were studied to track the ontogeny of parietal podocytes. The podocyte protein labeling detected parietal podocytes in all of the kidneys, was found in 76.6% on average of Bowman's capsule sections, and was prominent at the vascular pole. WT1 and p57 were expressed in some parietal cells, whereas PAX2 was present in all or most of them, so some parietal cells coexpressed WT1 and PAX2. Furthermore, parietal podocytes coexpressed WT1 and podocyte proteins. Cytokeratin-positive cells covered a variable part of the capsule and did not express podocyte proteins. Tuft-capsular podocyte bridges were present in 15.5 +/- 3.7% of the glomerular sections. Parietal podocytes often covered the juxtaglomerular arterioles and were present within the extraglomerular mesangium. Parietal podocytes were present in fetal kidneys. Parietal podocytes that express the same epitopes as visceral podocytes do exist along Bowman's capsule in the normal adult kidney. They are a constitutive cell type of the Bowman's capsule. Therefore, their role in physiology and pathology should be investigated.

  20. Temporal structure in neuronal activity during working memory in Macaque parietal cortex

    CERN Document Server

    Pesaran, B; Sahami, M; Mitra, P; Andersen, R A

    2000-01-01

    A number of cortical structures are reported to have elevated single unit firing rates sustained throughout the memory period of a working memory task. How the nervous system forms and maintains these memories is unknown but reverberating neuronal network activity is thought to be important. We studied the temporal structure of single unit (SU) activity and simultaneously recorded local field potential (LFP) activity from area LIP in the inferior parietal lobe of two awake macaques during a memory-saccade task. Using multitaper techniques for spectral analysis, which play an important role in obtaining the present results, we find elevations in spectral power in a 50--90 Hz (gamma) frequency band during the memory period in both SU and LFP activity. The activity is tuned to the direction of the saccade providing evidence for temporal structure that codes for movement plans during working memory. We also find SU and LFP activity are coherent during the memory period in the 50--90 Hz gamma band and no consisten...

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

    Science.gov (United States)

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

    2014-01-01

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

  2. White Matter Tracts Connected to the Medial Temporal Lobe Support the Development of Mnemonic Control.

    Science.gov (United States)

    Wendelken, Carter; Lee, Joshua K; Pospisil, Jacqueline; Sastre, Marcos; Ross, Julia M; Bunge, Silvia A; Ghetti, Simona

    2015-09-01

    One of the most important factors driving the development of memory during childhood is mnemonic control, or the capacity to initiate and maintain the processes that guide encoding and retrieval operations. The ability to selectively attend to and encode relevant stimuli is a particularly useful form of mnemonic control, and is one that undergoes marked improvement over childhood. We hypothesized that structural integrity of white matter tracts, in particular those connecting medial temporal lobe memory regions to other cortical areas, and/or those connecting frontal and parietal control regions, should contribute to successful mnemonic control. To test this hypothesis, we examined the relationship between structural integrity of selected white matter tracts and an experimental measure of mnemonic control, involving enhancement of memory by attention at encoding, in 116 children aged 7-11 and 25 young adults. We observed a positive relationship between integrity of uncinate fasciculus and mnemonic enhancement across age groups. In adults, but not in children, we also observed an association between mnemonic enhancement and integrity of ventral cingulum bundle and ventral fornix/fimbria. Integrity of fronto-parietal tracts, including dorsal cingulum and superior longitudinal fasciculus, was unrelated to mnemonic enhancement. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Motor role of parietal cortex in a monkey model of hemispatial neglect.

    Science.gov (United States)

    Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

    2015-04-21

    Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

  4. Caracterización del injerto parietal

    Directory of Open Access Journals (Sweden)

    José Manuel Díaz Fernández

    1996-12-01

    Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo de 22 pacientes en los que se utilizó el injerto parietal autógeno para reconstruir defectos del cráneo, en los servicios de Cirugía Maxilofacial y Neurocirugía del Hospital Clinicoquirúrgico Docente "Saturnino Lora", de Santiago de Cuba, desde 1988 hasta 1991. El método de extracción del injerto con división in situ resultó el más empleado y el que ofreció las mejores posibilidades de reconstrucción en cuanto a forma, volumen y flexibilidad, por lo que se recomienda en los defectos pequeños y medianos, sobre todo de la región frontal y áreas adyacentes, donde el contorno y la simetría son los 2 aspectos fundamentales que se deben conseguir. El método de división, in vitro se utilizó en las reconstrucciones de las deformidades de grandes dimensiones, particularmente en aquellas que no incluían la frente. El índice de complicaciones fue bajoIt was carried out a descriptive, longitudinal and prospective study of 22 patients in whom an autogenous parietal graft was used to reconstruct cranial defects at the Maxillofacial Surgery and Neurosurgery Department of the "Saturnino Lora" Clinical and Surgical Teaching Hospital, in Santiago de Cuba, from 1988 to 1991. The graft extraction method with division in situ was the most used and offered the best possibilities for reconstruction as regards form, volume and flexibility. Therefore, it is recommended for small and medium defects, particularly of the frontal region and adjacent areas, where contour and symmetry are the two fundamental aspects to be taken into consideration. The method of division in vitro was used to reconstruct large deformities, specially those in which the forehead was not included. The complications index was low

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

    Science.gov (United States)

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

    2014-06-01

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

  6. Navigating actions through the rodent parietal cortex

    Directory of Open Access Journals (Sweden)

    Jonathan R. Whitlock

    2014-05-01

    Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

  7. Quantifying interictal metabolic activity in human temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.; Christenson, P.D.; Zhang, J.X.; Phelps, M.E.; Kuhl, D.E.

    1990-01-01

    The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on [18F]fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a single investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism

  8. Changes in frontal lobe function before and after surgery in patients with unruptured intracranial aneurysm

    International Nuclear Information System (INIS)

    Ozaki, Saya; Kumon, Yoshiaki; Igase, Keiji; Watanabe, Hideaki; Ohnishi, Takanori

    2008-01-01

    We evaluated neuropsychological function in 18 patients with unruptured cerebral aneurysm who showed good postoperative outcomes. We paid particular attention to frontal lobe function. We also investigated relationships between cerebral blood flow (CBF) and frontal lobe function. Patients were examined using digit span, word fluency (WF), Stroop and trail-making tests to clarify frontal lobe function before and 1-2 months after surgery. We also used the mini-mental state examination (MMSE), Raven's colored progressive matrices (RCPM) and revised Wechsler adult intelligence scale (WAIS-R) to examine cognitive function. CBF was measured using 133 Xe-single photon emission computed tomography (SPECT) before and 1-2 months after surgery. Tests revealed that the patients' postoperative neuropsychological status was improved compared to the preoperative status for MMSE, RCPM and WAIS-R. Among the tests of frontal lobe function, WF results had deteriorated significantly after surgery. Resting CBF in the frontal lobe was significantly decreased. Regional CBF in the frontal lobe was decreased significantly in comparison with values in the parietal and temporal lobes in patients showing deterioration of WF. Deterioration of WF correlated with CBF changes in the frontal lobe. These results suggest that surgery for unruptured cerebral aneurysm exerts detrimental effects on frontal lobe function that may be related to CBF changes. (author)

  9. 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.

  10. The structure of the parietal pleura and its relationship to pleural liquid dynamics in sheep.

    Science.gov (United States)

    Albertine, K H; Wiener-Kronish, J P; Staub, N C

    1984-03-01

    We studied the parietal pleura of six sheep to obtain information on pleural structure, blood supply, and lymphatic drainage. In the strict sense, the parietal pleura is composed of a single layer of mesothelial cells and a uniform layer of loose, irregular connective tissue (about 23 micron in width) subjacent to the mesothelial cells. The parietal pleural blood vessels are 10-15 micron from the pleural space. Tracer substances put in the pleural space are removed at specific locations. Colloidal carbon and chick red blood cells are cleared by the parietal pleural lymphatics located over the intercostal spaces at the caudal end of the thoracic wall and over the lateral sides of the pericardial sac. In these areas the mesothelial cells have specialized openings, the stomata, that directly communicate with the underlying lymphatic lacunae. Cells and particulate matter in the pleural space are cleared only by the parietal pleural lymphatics. Compared to the visceral pleura, we believe the thinness of the parietal pleura, the closeness of its blood vessels to the pleural space, and its specialized lymphatic clearance pathways, together indicate that the parietal pleura plays a major role in pleural liquid and protein dynamics in sheep.

  11. Early seizure propagation from the occipital lobe to medial temporal structures and its surgical implication.

    Science.gov (United States)

    Usui, Naotaka; Mihara, Tadahiro; Baba, Koichi; Matsuda, Kazumi; Tottori, Takayasu; Umeoka, Shuichi; Nakamura, Fumihiro; Terada, Kiyohito; Usui, Keiko; Inoue, Yushi

    2008-12-01

    Intracranial EEG documentation of seizure propagation from the occipital lobe to medial temporal structures is relatively rare. We retrospectively analyzed intracranial EEG recorded with electrodes implanted in the medial temporal lobe in patients who underwent occipital lobe surgery. Four patients with occipital lesions, who underwent intracranial EEG monitoring with intracerebral electrodes implanted in the medial temporal lobe prior to occipital lobe surgery, were studied. Subdural electrodes were placed over the occipital lobe and adjacent areas. Intracerebral electrodes were implanted into bilateral hippocampi and the amygdala in three patients, and in the hippocampus and amygdala ipsilateral to the lesion in one. In light of the intracranial EEG findings, the occipital lobe was resected but the medial temporal lobe was spared in all patients. The follow-up period ranged from six to 16 years, and seizure outcome was Engel Class I in all patients. Sixty six seizures were analyzed. The majority of the seizures originated from the occipital lobe. In complex partial seizures, ictal discharges propagated to the medial temporal lobe. No seizures originating from the temporal lobe were documented. In some seizures, the ictal-onset zone could not be identified. In these seizures, very early propagation to the medial temporal lobe was observed. Interictal spikes were recorded in the medial temporal lobe in all cases. Intracranial EEG revealed very early involvement of the medial temporal lobe in some seizures. Seizure control was achieved without resection of the medial temporal structures.

  12. Medial temporal lobe

    International Nuclear Information System (INIS)

    Silver, A.J.; Cross, D.T.; Friedman, D.P.; Bello, J.A.; Hilal, S.K.

    1989-01-01

    To better define the MR appearance of hippocampal sclerosis, the authors have reviewed over 500 MR coronal images of the temporal lobes. Many cysts were noted that analysis showed were of choroid-fissure (arachnoid) origin. Their association with seizures was low. A few nontumorous, static, medial temporal lesions, noted on T2-weighted coronal images, were poorly visualized on T1-weighted images and did not enhance with gadolinium. The margins were irregular, involved the hippocampus, and were often associated with focal atrophy. The lesions usually were associated with seizure disorders and specific electroencephalographic changes, and the authors believe they represented hippocampal sclerosis

  13. Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lunkka, J. P.; Moisio, K.; Vainio, A. [Univ. of Oulu (Finland)

    2013-07-15

    It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

  14. Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

    International Nuclear Information System (INIS)

    Lunkka, J. P.; Moisio, K.; Vainio, A.

    2013-07-01

    It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

  15. Transient attenuation of visual evoked potentials during focal status epilepticus in a patient with occipital lobe epilepsy.

    Science.gov (United States)

    Tsai, Meng-Han; Hsu, Shih-Pin; Huang, Chi-Ren; Chang, Chen-Sheng; Chuang, Yao-Chung

    2010-06-01

    Seizures originating in the occipital areas are relatively uncommon. They are usually characterized by visual hallucinations and illusions or other symptoms related to the eyes and vision. In a 54-year-old woman with occipital lobe epilepsy, complex visual hallucinations, illusions, and migraine-like headache constitute the major clinical manifestations. During focal status epilepticus, ictal electroencephalography revealed rhythmic focal spikes in the right occipital region, rapidly propagating to the right parietal and contralateral occipital areas. Ictal brain single-photon emission computed topography revealed hyperperfusion of the right occipital region. Using a full-field pattern-shift visual evoked potential (VEP) study, we found that the P100 responses on both sides were markedly attenuated in amplitude during occipital focal status epilepticus, whereas the latencies of the VEPs were normal. The amplitude and morphology of P100 responses on both sides, however, returned to the normal range 7 days after cessation of the seizures. In addition to clinical seizure semiology, scalp EEG, SPECT and neuroimaging studies, VEP studies may be used as a supplementary examination tool to provide further information in the patients with occipital lobe seizures or epilepsies.

  16. Motor imagery training: Kinesthetic imagery strategy and inferior parietal fMRI activation.

    Science.gov (United States)

    Lebon, Florent; Horn, Ulrike; Domin, Martin; Lotze, Martin

    2018-04-01

    Motor imagery (MI) is the mental simulation of action frequently used by professionals in different fields. However, with respect to performance, well-controlled functional imaging studies on MI training are sparse. We investigated changes in fMRI representation going along with performance changes of a finger sequence (error and velocity) after MI training in 48 healthy young volunteers. Before training, we tested the vividness of kinesthetic and visual imagery. During tests, participants were instructed to move or to imagine moving the fingers of the right hand in a specific order. During MI training, participants repeatedly imagined the sequence for 15 min. Imaging analysis was performed using a full-factorial design to assess brain changes due to imagery training. We also used regression analyses to identify those who profited from training (performance outcome and gain) with initial imagery scores (vividness) and fMRI activation magnitude during MI at pre-test (MI pre ). After training, error rate decreased and velocity increased. We combined both parameters into a common performance index. FMRI activation in the left inferior parietal lobe (IPL) was associated with MI and increased over time. In addition, fMRI activation in the right IPL during MI pre was associated with high initial kinesthetic vividness. High kinesthetic imagery vividness predicted a high performance after training. In contrast, occipital activation, associated with visual imagery strategies, showed a negative predictive value for performance. Our data echo the importance of high kinesthetic vividness for MI training outcome and consider IPL as a key area during MI and through MI training. © 2018 Wiley Periodicals, Inc.

  17. Cognitive dysfunctions in occipital lobe epilepsy compared to temporal lobe epilepsy.

    Science.gov (United States)

    Santangelo, Gabriella; Trojano, Luigi; Vitale, Carmine; Improta, Ilaria; Alineri, Irma; Meo, Roberta; Bilo, Leonilda

    2017-06-01

    To compare cognitive profiles of occipital lobe epilepsy (OLE) and temporal lobe epilepsy (TLE) and to investigate whether impairment of visuospatial functions is a specific deficit of OLE. Eighteen patients with OLE, 18 patients with TLE, and 18 controls underwent a neuropsychological battery assessing memory, visuospatial functions, and frontal/executive functions. Multivariate analysis evidenced poorer performance of patients with TLE and patients with OLE relative to controls on tasks assessing verbal and non-verbal long-term memory, frontal functions, and visuospatial functions. Patients with OLE had poorer performance than patients with TLE on visuospatial tasks, whereas patients with TLE performed worse than patients with OLE on verbal long-term memory test. Discriminant analysis identified two canonical discriminant functions: The first explained 53.3% of the variance, and the second explained 46.7% of the variance. The first function included verbal and non-verbal memory tests distinguishing controls from both OLE and TLE, whereas the second factor including a visuoconstructional test distinguished OLE from TLE and controls. The results demonstrate that visuoconstructional dysfunction is related to OLE and support the idea that alterations of occipito-parietal stream may be specific to patients with OLE. © 2015 The British Psychological Society.

  18. Reduced parietal activation in cervical dystonia after parietal TMS interleaved with fMRI

    NARCIS (Netherlands)

    de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Hinson, Vanessa K.; George, Mark S.; Leenders, Klaus L.

    Objective: Clinically normal hand movement with altered cerebral activation patterns in cervical dystonia (CD) may imply cerebral adaptation. Since impaired sensorimotor integration appears to play a role in dystonia, left superior parietal cortex modulation with repetitive transcranial magnetic

  19. The anatomy of the human medial forebrain bundle: Ventral tegmental area connections to reward-associated subcortical and frontal lobe regions

    Directory of Open Access Journals (Sweden)

    Volker Arnd Coenen

    Full Text Available Introduction: Despite their importance in reward, motivation, and learning there is only sparse anatomical knowledge about the human medial forebrain bundle (MFB and the connectivity of the ventral tegmental area (VTA. A thorough anatomical and microstructural description of the reward related PFC/OFC regions and their connection to the VTA - the superolateral branch of the MFB (slMFB - is however mandatory to enable an interpretation of distinct therapeutic effects from different interventional treatment modalities in neuropsychiatric disorders (DBS, TMS etc.. This work aims at a normative description of the human MFB (and more detailed the slMFB anatomy with respect to distant prefrontal connections and microstructural features. Methods and material: Healthy subjects (n = 55; mean age ± SD, 40 ± 10 years; 32 females underwent high resolution anatomical magnetic resonance imaging including diffusion tensor imaging. Connectivity of the VTA and the resulting slMFB were investigated on the group level using a global tractography approach. The Desikan/Killiany parceling (8 segments of the prefrontal cortex was used to describe sub-segments of the MFB. A qualitative overlap with Brodmann areas was additionally described. Additionally, a pure visual analysis was performed comparing local and global tracking approaches for their ability to fully visualize the slMFB. Results: The MFB could be robustly described both in the present sample as well as in additional control analyses in data from the human connectome project. Most VTA- connections reached the superior frontal gyrus, the middel frontal gyrus and the lateral orbitofrontal region corresponding to Brodmann areas 10, 9, 8, 11, and 11m. The projections to these regions comprised 97% (right and 98% (left of the total relative fiber counts of the slMFB. Discussion: The anatomical description of the human MFB shows far reaching connectivity of VTA to reward-related subcortical and

  20. Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

    Science.gov (United States)

    Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

    2015-02-15

    The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Hepatocellular carcinoma in Riedel's lobe.

    Science.gov (United States)

    Zamfir, R; Braşoveanu, V; Boroş, M; Herlea, V; Popescu, I

    2008-01-01

    We present a rare case of 65-year female with right abdominal mass and abdominal discomfort; a combination of Doppler ultrasonography, computed tomography and laparotomy was utilized to make a diagnosis of tumoral Riedel's lobe. In our case, laparotomy with resection of Riedel's lobe was the proper therapeutical solution.

  2. Regional intercostal bulging of the parietal pleura

    International Nuclear Information System (INIS)

    Jantsch, H.; Greene, R.; Lechner, G.; Mavritz, W.; Pichler, W.; Winkler, M.; Zadrobilek, E.

    1989-01-01

    This paper describes bedside radiographs with localized intercostal bulging as the sole indication of tension pneumothorax in six patients with acute deterioration in gas exchange. Relief of the pneumothorax was followed by a rush of gas from the tension space and a prompt improvement in gas exchange. The authors concluded the regional intercostal bulging of the parietal pleura may be the sole indicator of life-threatening tension pneumothorax in patients on mechanical ventilation

  3. The neocortical network representing associative memory reorganizes with time in a process engaging the anterior temporal lobe.

    Science.gov (United States)

    Nieuwenhuis, Ingrid L C; Takashima, Atsuko; Oostenveld, Robert; McNaughton, Bruce L; Fernández, Guillén; Jensen, Ole

    2012-11-01

    During encoding, the distributed neocortical representations of memory components are presumed to be associatively linked by the hippocampus. With time, a reorganization of brain areas supporting memory takes place, which can ultimately result in memories becoming independent of the hippocampus. While it is theorized that with time, the neocortical representations become linked by higher order neocortical association areas, this remains to be experimentally supported. In this study, 24 human participants encoded sets of face-location associations, which they retrieved 1 or 25 h later ("recent" and "remote" conditions, respectively), while their brain activity was recorded using whole-head magnetoencephalography. We investigated changes in the functional interactions between the neocortical representational areas emerging over time. To assess functional interactions, trial-by-trial high gamma (60-140 Hz) power correlations were calculated between the neocortical representational areas relevant to the encoded information, namely the fusiform face area (FFA) and posterior parietal cortex (PPC). With time, both the FFA and the PPC increased their functional interactions with the anterior temporal lobe (ATL). Given that the ATL is involved in semantic representation of paired associates, our results suggest that, already within 25 h after acquiring new memory associations, neocortical functional links are established via higher order semantic association areas.

  4. Mirror Focus in a Patient with Intractable Occipital Lobe Epilepsy

    OpenAIRE

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

    2014-01-01

    Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy....

  5. Dynamic perfusion patterns in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Dupont, Patrick; Paesschen, Wim van; Zaknun, John J.; Maes, Alex; Tepmongkol, Supatporn; Locharernkul, Chaichon; Vasquez, Silvia; Carpintiero, Silvina; Bal, C.S.; Dondi, Maurizio

    2009-01-01

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  6. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  7. Transient simulation in interior flow field of lobe pump

    International Nuclear Information System (INIS)

    Li, Y B; Sang, X H; Shen, H; Jia, K; Meng, Q W

    2013-01-01

    The subject of this paper is mainly focused on the development and control of the double folium and trifolium lobe pump profiles by using the principle of involute engagement and use CAD to get an accurate involute profile. We use the standard k-ε turbulence model and PISO algorithm based on CFD software FLUENT. The dynamic mesh and UDF technology is introduced to simulate the interior flow field inside a lobe pump, and the variation of interior flow field under the condition of the lobe rotating is analyzed. We also analyse the influence produced by the difference in lobes, and then reveal which lobe is best. The results show that dynamic variation of the interior flow field is easily obtained by dynamic mesh technology and the distribution of its pressure and velocity. Because of the small gaps existing between the rotors and pump case, the higher pressure area will flow into the lower area though the small gaps which cause the working area keep with higher pressure all the time. Both of the double folium and trifolium are existing the vortex during the rotting time and its position, size and shape changes all the time. The vortexes even disappear in a circle period and there are more vortexes in double folium lobe pump. The velocity and pressure pulsation of trifolium pump are lower than that of the double folium

  8. Transcriptional landscape of glomerular parietal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Sina A Gharib

    Full Text Available Very little is known about the function of glomerular parietal epithelial cells (PECs. In this study, we performed genome-wide expression analysis on PEC-enriched capsulated vs. PEC-deprived decapsulated rat glomeruli to determine the transcriptional state of PECs under normal conditions. We identified hundreds of differentially expressed genes that mapped to distinct biologic modules including development, tight junction, ion transport, and metabolic processes. Since developmental programs were highly enriched in PECs, we characterized several of their candidate members at the protein level. Collectively, our findings confirm that PECs are multifaceted cells and help define their diverse functional repertoire.

  9. Thalamic and parietal brain morphology predicts auditory category learning.

    Science.gov (United States)

    Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

    2014-01-01

    Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

  10. Right parietal cortex mediates recognition memory for melodies.

    Science.gov (United States)

    Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

    2015-07-01

    Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Sex-dependent age modulation of frontostriatal and temporo-parietal activation during cognitive control.

    Science.gov (United States)

    Christakou, Anastasia; Halari, Rozmin; Smith, Anna B; Ifkovits, Eve; Brammer, Mick; Rubia, Katya

    2009-10-15

    Developmental functional imaging studies of cognitive control show progressive age-related increase in task-relevant fronto-striatal activation in male development from childhood to adulthood. Little is known, however, about how gender affects this functional development. In this study, we used event related functional magnetic resonance imaging to examine effects of sex, age, and their interaction on brain activation during attentional switching and interference inhibition, in 63 male and female adolescents and adults, aged 13 to 38. Linear age correlations were observed across all subjects in task-specific frontal, striatal and temporo-parietal activation. Gender analysis revealed increased activation in females relative to males in fronto-striatal areas during the Switch task, and laterality effects in the Simon task, with females showing increased left inferior prefrontal and temporal activation, and males showing increased right inferior prefrontal and parietal activation. Increased prefrontal activation clusters in females and increased parietal activation clusters in males furthermore overlapped with clusters that were age-correlated across the whole group, potentially reflecting more mature prefrontal brain activation patterns for females, and more mature parietal activation patterns for males. Gender by age interactions further supported this dissociation, revealing exclusive female-specific age correlations in inferior and medial prefrontal brain regions during both tasks, and exclusive male-specific age correlations in superior parietal (Switch task) and temporal regions (Simon task). These findings show increased recruitment of age-correlated prefrontal activation in females, and of age-correlated parietal activation in males, during tasks of cognitive control. Gender differences in frontal and parietal recruitment may thus be related to gender differences in the neurofunctional maturation of these brain regions.

  12. MRI findings of temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Nakahara, Ichiro; Yin, Dali; Fukami, Masahiro; Kondo, Seiji; Takeuchi, Juji; Kanemoto, Kousuke; Sengoku, Akira; Kawai, Itsuo

    1992-01-01

    MRI findings were analyzed retrospectively in 46 patients with temporal lobe epilepsy in which the side of epileptogenic focus had been confirmed by EEG studies. T 1 - and T 2 -weighted images were obtained by the use of a 1.0 or 1.5 T superconducting-type MRI machine with a coronal scan perpendicular to the axis of the temporal horn of the lateral ventricle. Additional axial and sagittal scans were performed in some cases. The area of the hippocampal body was measured quantitatively using a computerized image-analysis system in 26 cases in which the hippocampus had been visualized with enough contrast on T 1 -weighted coronal images. Abnormal findings were observed in 31/46 (67%) cases. Hippocampal (HC) and temporal lobe (TL) atrophy were observed in 18/46 (39%) and 23/46 (50%) cases respectively, and the side of the atrophy corresponded with the side of the epileptogenic focus, as confirmed by EEG studies, with specificities of 89% and 74% respectively. A quantitative measurement of the area of the hippocampal body showed unilateral hippocampal atrophy more than 10% in 18/25 (69%) cases (10-25%: 10 cases, 25-50%: 7 cases, 50% 2 abnormality was observed in only 4 cases. Structural lesions were observed in 4 cases including an arachnoid cyst, an astrocytoma in amygdala, the Dandy-Walker syndrome, and tuberous sclerosis, using the more efficient imaging qualities than the CT scan. From these observations, it is apparant that superconducting MRI is extremely useful in the diagnosis of the epileptogenic topography of temporal lobe epilepsy. Particularly, hippocampal atrophy was found to correspond with the side of the epileptogenic focus on EEG with a high specificity; its quantitative evaluation could be one of the most important standards in detecting the operative indications for temporal lobe epilepsy. (author)

  13. Executive Functions in Healthy Older Adults Are Differentially Related to Macro- and Microstructural White Matter Characteristics of the Cerebral Lobes

    Directory of Open Access Journals (Sweden)

    Sarah Hirsiger

    2017-11-01

    Full Text Available Aging is associated with microstructural white matter (WM changes. WM microstructural characteristics, measured with diffusion tensor imaging (DTI, are different in normal appearing white matter (NAWM and WM hyperintensities (WMH. It is largely unknown how the microstructural properties of WMH are associated with cognition and if there are regional effects for specific cognitive domains. We therefore examined within 200 healthy older participants (a differences in microstructural characteristics of NAWM and WMH per cerebral lobe; and (b the association of macrostructural (WMH volume and microstructural characteristics (within NAWM and WMH separately of each lobe with measures of executive function and processing speed. Multi-modal imaging (i.e., T1, DTI, and FLAIR was used to assess WM properties. The Stroop and the Trail Making Test were used to measure inhibition, task-switching (both components of executive function, and processing speed. We observed that age was associated with deterioration of white matter microstructure of the NAWM, most notably in the frontal lobe. Older participants had larger WMH volumes and lowest fractional anisotropy values within WMH were found in the frontal lobe. Task-switching was associated with cerebral NAWM volume and NAWM volume of all lobes. Processing speed was associated with total NAWM volume, and microstructural properties of parietal NAWM, the parietal WMH, and the temporal NAWM. Task-switching was related to microstructural properties of WMH of the frontal lobe and WMH volume of the parietal lobe. Our results confirm that executive functioning and processing speed are uniquely associated with macro- and microstructural properties of NAWM and WMH. We further demonstrate for the first time that these relationships differ by lobar region. This warrants the consideration of these distinct WM indices when investigating cognitive function.

  14. Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

    Science.gov (United States)

    Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T.

    2012-01-01

    Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization. PMID:22347175

  15. Unique and shared roles of the posterior parietal and dorsolateral prefrontal cortex in cognitive functions

    Directory of Open Access Journals (Sweden)

    Fumi eKatsuki

    2012-05-01

    Full Text Available The dorsolateral prefrontal and posterior parietal cortex are two parts of a broader brain network involved in the control of cognitive functions such as working memory, spatial attention, and decision making. The two areas share many functional properties and exhibit similar patterns of activation during the execution of mental operations. However, neurophysiological experiments in non-human primates have also documented subtle differences, revealing functional specialization within the fronto-parietal network. These differences include the ability of the dorsolateral prefrontal cortex to influence memory performance, attention allocation and motor responses to a greater extent, and to resist interference by distracting stimuli. In recent years, distinct cellular and anatomical differences have been identified, offering insights into how functional specialization is achieved. This article reviews the common functions and functional differences between the dorsolateral prefrontal and posterior parietal cortex, and their underlying mechanisms.

  16. Fractionation of parietal function in bistable perception probed with concurrent TMS-EEG.

    Science.gov (United States)

    Schauer, Georg; Chang, Acer; Schwartzman, David; Rae, Charlotte L; Iriye, Heather; Seth, Anil K; Kanai, Ryota

    2016-08-16

    When visual input has conflicting interpretations, conscious perception can alternate spontaneously between these possible interpretations. This is called bistable perception. Previous neuroimaging studies have indicated the involvement of two right parietal areas in resolving perceptual ambiguity (ant-SPLr and post-SPLr). Transcranial magnetic stimulation (TMS) studies that selectively interfered with the normal function of these regions suggest that they play opposing roles in this type of perceptual switch. In the present study, we investigated this fractionation of parietal function by use of combined TMS with electroencephalography (EEG). Specifically, while participants viewed either a bistable stimulus, a replay stimulus, or resting-state fixation, we applied single pulse TMS to either location independently while simultaneously recording EEG. Combined with participant's individual structural magnetic resonance imaging (MRI) scans, this dataset allows for complex analyses of the effect of TMS on neural time series data, which may further elucidate the causal role of the parietal cortex in ambiguous perception.

  17. Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

    Science.gov (United States)

    Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

    2016-02-01

    When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

    Science.gov (United States)

    van Leeuwen, Tessa M; Petersson, Karl Magnus; Hagoort, Peter

    2010-08-10

    In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to play an important role, may induce V4 activation and the percept of

  19. Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

    Directory of Open Access Journals (Sweden)

    Tessa M van Leeuwen

    Full Text Available BACKGROUND: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour. Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. METHODOLOGY/PRINCIPAL FINDINGS: First, in a free viewing functional magnetic resonance imaging (fMRI experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. CONCLUSIONS/SIGNIFICANCE: Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal

  20. Origin of frontal lobe spikes in the early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome).

    Science.gov (United States)

    Leal, Alberto J R; Ferreira, José C; Dias, Ana I; Calado, Eulália

    2008-09-01

    Early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome [PS]) is a common and easily recognizable epilepsy. Interictal EEG spike activity is often multifocal but most frequently localized in the occipital lobes. The origin and clinical significance of the extra-occipital spikes remain poorly understood. Three patients with the PS and interictal EEG spikes with frontal lobe topography were studied using high-resolution EEG. Independent component analysis (ICA) was used to decompose the spikes in components with distinct temporal dynamics. The components were mapped in the scalp with a spline-laplacian algorithm. The change in scalp potential topography from spike onset to peak, suggests the contribution of several intracranial generators, with different kinetics of activation and significant overlap. ICA was able to separate the major contributors to frontal spikes and consistently revealed an early activating group of components over the occipital areas in all the patients. The local origin of these early potentials was established by the spline-laplacian montage. Frontal spikes in PS are consistently associated with early and unilateral occipital lobe activation, suggesting a postero-anterior spike propagation. Frontal spikes in the PS represent a secondary activation triggered by occipital interictal discharges and do not represent an independent focus.

  1. Temporo-Parietal Junction Activity in Theory-of-Mind Tasks: Falseness, Beliefs, or Attention

    Science.gov (United States)

    Aichhorn, Markus; Perner, Josef; Weiss, Benjamin; Kronbichler, Martin; Staffen, Wolfgang; Ladurner, Gunther

    2009-01-01

    By combining the false belief (FB) and photo (PH) vignettes to identify theory-of-mind areas with the false sign (FS) vignettes, we re-establish the functional asymmetry between the left and right temporo-parietal junction (TPJ). The right TPJ (TPJ-R) is specially sensitive to processing belief information, whereas the left TPJ (TPJ-L) is equally…

  2. Muscarinic responses of gastric parietal cells

    International Nuclear Information System (INIS)

    Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G.

    1991-01-01

    Isolated rabbit gastric glands were used to study the nature of the muscarinic cholinergic responses of parietal cells. Carbachol stimulation of acid secretion, as measured by the accumulation of aminopyrine, was inhibited by the M1 antagonist, pirenzepine, with an IC50 of 13 microM; by the M2 antagonist, 11,2-(diethylamino)methyl-1 piperidinyl acetyl-5,11-dihydro-6H-pyrido 2,3-b 1,4 benzodiazepin-6-one (AF-DX 116), with an IC50 of 110 microM; and by the M1/M3 antagonist, diphenyl-acetoxy-4-methylpiperidinemethiodide, with an IC50 of 35 nM. The three antagonists displayed equivalent IC50 values for the inhibition of carbachol-stimulated production of 14CO2 from radiolabeled glucose, which is a measure of the turnover of the H,K-ATPase, the final step of acid secretion. Intracellular calcium levels were measured in gastric glands loaded with FURA 2. Carbachol was shown to both release calcium from an intracellular pool and to promote calcium entry across the plasma membrane. The calcium entry was inhibitable by 20 microM La3+. The relative potency of the three muscarinic antagonists for inhibition of calcium entry was essentially the same as for inhibition of acid secretion or pump related glucose oxidation. Image analysis of the glands showed the effects of carbachol, and of the antagonists, on intracellular calcium were occurring largely in the parietal cell. The rise in cell calcium due to release of calcium from intracellular stores was inhibited by 4-DAMP with an IC50 of 1.7 nM, suggesting that the release pathway was regulated by a low affinity M3 muscarinic receptor or state; Ca entry and acid secretion are regulated by a high affinity M3 muscarinic receptor or state, inhibited by higher 4-DAMP concentrations, suggesting that it is the steady-state elevation of Ca that is related to parietal cell function rather than the [Ca]i transient

  3. Estudo histológico e computadorizado das áreas com células parietais e principais no estômago de ratos Wistar tratados com pantoprazol e "N-Nitroso-N-Methylurea"(NMU Histological and computer-assisted analysis of parietal and chief cells stomach areas in Wistar rats treated with pantoprazole and N-Nitroso-N-Methylurea (NMU

    Directory of Open Access Journals (Sweden)

    Iure Kalinine Ferraz de Souza

    2002-08-01

    Full Text Available O uso prolongado dos inibidores da bomba de prótons tem sido considerado uma condição de risco para o desenvolvimento de gastrite atrófica e tumores gástricos. Objetivo: Estudar o efeito do uso de pantoprazol (PTZ e carcinogênese pela "N-Nitroso-N-Methylurea" (NMU, por 15 semanas, sobre o estômago glandular de ratos Wistar, pela análise histológica e computadorizada das áreas com células parietais (AP, principais (AZ e da mucosa não oxíntica (ANO, além do estudo das alterações histopatológicas identificadas. Métodos: Quarenta ratos Wistar machos foram distribuídos em 4 grupos: G1 (controle, G2 (NMU+PTZ, G3 (PTZ e G4 (NMU. O pantoprazol foi administrado 2x/semana (14mg/kg de peso, i.p. e a NMU oferecida, ad libitum, diluída na água de beber (100mig/ml. Após o estudo histológico AP, AZ e ANO foram determinadas por análise computadorizada das imagens dos estômagos, utilizando o programa "ImageJ 1.19z". Resultados: Mostraram redução da AP e aumento da ANO, em G2, G3 e G4 (pThe long-term use of proton bomb inhibitors has been considered a risk condition for the development of atrophic gastritis and gastric tumors. Objective: The aim of this study was to investigate the effects of pantoprazole (PTZ treatment and N-Nitroso-N-Methylurea (NMU carcinogenesis, for 15 weeks, in the glandular stomach of rats by histological and computer-assisted analysis of parietal cells area (PA, chief cells area (CP and non-oxintic mucosal area (ANO, as well as by histopathological study. Methods: A total of 40 male Wistar rats were divided into four groups on the basis of the treatment: G1 (control, G2 (NMU+PTZ, G3 (PTZ and G4 (NMU. Pantoprazole was administered twice a week (14mg/kg body wt., i.p. and NMU was given in the drinking water (100ppm ad libitum. After histological examination AP, AZ and ANO were investigated by computer-assisted analysis of the stomach image using the program ImageJ1.19z. Results: Showed a reduction of AP and

  4. Auras and clinical features in temporal lobe epilepsy: a new approach on the basis of voxel-based morphometry.

    Science.gov (United States)

    Santana, Maria Teresa Castilho Garcia; Jackowski, Andrea Parolin; da Silva, Henrique Hattori; Caboclo, Luis Otávio Sales Ferreira; Centeno, Ricardo Silva; Bressan, Rodrigo A; Carrete, Henrique; Yacubian, Elza Márcia Targas

    2010-05-01

    MRI investigations in patients with temporal lobe epilepsy (TLE) with mesial temporal sclerosis (MTS) have demonstrated structural abnormalities extending beyond ipsilateral hippocampus which may be studied through voxel-based morphometry (VBM). We investigated brain morphology related to clinical features in patients with refractory TLE with MTS using VBM. One hundred patients with unilateral TLE with MTS (59 left) and 30 controls were enrolled. VBM5 was employed to analyze (1) hemispheric damage, (2) influence of initial precipitating injury (IPI): 23 patients with febrile seizures and 19 with status epilepticus, and (3) types of auras classified as: mesial, including psychic auras (19 patients); anterior mesio-lateral, as autonomic symptoms, specially epigastric auras (27 patients) and neocortical, which included auditory, vertiginous, somatosensory and visual auras (16 patients). (1) Left TLE patients presented more widespread gray matter volume (GMV) reductions affecting ipsilateral hippocampus, temporal neocortex, insula and also left uncus, precentral gyrus, thalamus, parietal lobule, cuneus and bilateral cingulum. (2) Febrile seizures group presented ipsilateral GMV reductions in hippocampus, neocortical temporal, frontal and occipital cortices, insula and cingulum. Status epilepticus group presented more widespread GMV reductions involving temporal and extratemporal lobes. (3) Patients with mesial auras showed significant ipsilateral GMV reductions in hippocampus and amygdala, particularly right TLE group, who presented greater extension of GMV reduction in the entorhinal cortex. Significant reductions in hippocampus, amygdala and insula were seen in patients with anterior mesio-lateral auras. This study evaluated a large number of TLE-MTS patients showing structural damage extending beyond hippocampus, and different types of IPI associated with the extension of brain damage. Subtypes of auras are related to different clusters of areas of GMV reductions in

  5. Medical image of the week: right middle lobe syndrome

    Directory of Open Access Journals (Sweden)

    Cristan EA

    2016-05-01

    Full Text Available No abstract available. Article truncated at 150 words. A 73 year-old woman, a lifetime non-smoker, presented to the pulmonary clinic with chronic dyspnea on exertion and cough. Physical exam was unremarkable and pulmonary function testing showed normal spirometry. A chest radiograph revealed calcified mediastinal adenopathy and increased density in the right middle lobe region (Figure 1. A computed tomography scan of the chest revealed significant narrowing of the right middle lobe bronchus with partial atelectasis and prominent calcified mediastinal lymphadenopathy (Figure 2. Bronchoscopy showed no endobronchial lesions but there was evidence of extrinsic compression surrounding the right middle lobe orifice. An endobronchial biopsy revealed noncaseating granulomas. Bronchoscopy cultures and cytology were negative and this was presumed to be from a previous infection with histoplasmosis given the patient’s long-term residence in an endemic area. Given chronic narrowing of right middle lobe bronchus with persistent atelectasis of the right middle lobe, the patient was diagnosed with right middle lobe syndrome. ...

  6. Immunohistochemical study of Metallothionein in patients with temporal lobe epilepsy.

    Science.gov (United States)

    Juárez-Rebollar, Daniel; Alonso-Vanegas, Mario; Nava-Ruíz, Concepción; Buentello-García, Masao; Yescas-Gómez, Petra; Díaz-Ruíz, Araceli; Rios, Camilo; Méndez-Armenta, Marisela

    2017-05-01

    Epilepsy is characterized by spontaneous recurrent seizures and temporal lobe epilepsy (TLE) is the most common serious neurological example of acquired and frequent epilepsy. Oxidative stress is recognized as playing a contributing role in several neurological disorders, and most recently have been implicated in acquired epilepsies. The MTs occur in several brain regions and may serve as neuroprotective proteins against reactive oxygen species causing oxidative damage and stress. The main aim of this work was to describe the immunohistochemical localization of MT in the specimens derived from the patients affected by TLE. Histopathological examination showed NeuN, GFAP and MT immunopositive cells that were analyzed for determinate in hippocampal and parietal cortex samples. An increase in the reactive gliosis associated with increased MT expression was observed in patients with TLE. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

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

  8. Altered organization of face processing networks in temporal lobe epilepsy

    Science.gov (United States)

    Riley, Jeffrey D.; Fling, Brett W.; Cramer, Steven C.; Lin, Jack J.

    2015-01-01

    SUMMARY Objective Deficits in social cognition are common and significant in people with temporal lobe epilepsy (TLE), but the functional and structural underpinnings remain unclear. The present study investigated how the side of seizure focus impacts face processing networks in temporal lobe epilepsy. Methods We used functional magnetic resonance imaging (fMRI) of a face processing paradigm to identify face responsive regions in 24 individuals with unilateral temporal lobe epilepsy (Left = 15; Right = 9) and 19 healthy controls. fMRI signals of face responsive regions ispilateral and contralateral to the side of seizure onset were delineated in TLE and compared to the healthy controls with right and left side combined. Diffusion tensor images were acquired to investigate structural connectivity between face regions that differed in fMRI signals between the two groups. Results In temporal lobe epilepsy, activation of the cortical face processing networks varied according to side of seizure onset. In temporal lobe epilepsy, the laterality of amygdala activation was shifted to the side contralateral to the seizure focus while controls showed no significant asymmetry. Furthermore, compared to controls, patients with TLE showed decreased activation of the occipital face responsive region in the ipsilateral side and an increased activity of the anterior temporal lobe in the contralateral side to the seizure focus. Probabilistic tractography revealed that the occipital face area and anterior temporal lobe are connected via the inferior longitudinal fasciculus, which in individuals with temporal lobe epilepsy showed reduced integrity. Significance Taken together, these findings suggest that brain function and white matter integrity of networks subserving face processing are impaired on the side of seizure onset, accompanied by altered responses on the side contralateral to the seizure. PMID:25823855

  9. Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

    Directory of Open Access Journals (Sweden)

    Muriel Anne Lobier

    2014-07-01

    Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

  10. Differentiated parietal connectivity of frontal regions for "what" and "where" memory.

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    Rottschy, C; Caspers, S; Roski, C; Reetz, K; Dogan, I; Schulz, J B; Zilles, K; Laird, A R; Fox, P T; Eickhoff, S B

    2013-11-01

    In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann's area BA 44). As similar locations have been discussed as part of a dorsal frontal-superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related "what" and "where" processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may

  11. Cortico-cortical connections of areas 44 and 45B in the macaque monkey.

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    Frey, Stephen; Mackey, Scott; Petrides, Michael

    2014-04-01

    In the human brain, areas 44 and 45 constitute Broca's region, the ventrolateral frontal region critical for language production. The homologues of these areas in the macaque monkey brain have been established by direct cytoarchitectonic comparison with the human brain. The cortical areas that project monosynaptically to areas 44 and 45B in the macaque monkey brain require clarification. Fluorescent retrograde tracers were placed in cytoarchitectonic areas 44 and 45B of the macaque monkey, as well as in the anterior part of the inferior parietal lobule and the superior temporal gyrus. The results demonstrate that ipsilateral afferent connections of area 44 arise from local frontal areas, including rostral premotor cortical area 6, from secondary somatosensory cortex, the caudal insula, and the cingulate motor region. Area 44 is strongly linked with the anterior inferior parietal lobule (particularly area PFG and the adjacent anterior intraparietal sulcus). Input from the temporal lobe is limited to the fundus of the superior temporal sulcus extending caudal to the central sulcus. There is also input from the sulcal part of area Tpt in the upper bank of the superior temporal sulcus. Area 45B shares some of the connections of area 44, but can be distinguished from area 44 by input from the caudal inferior parietal lobule (area PG) and significant input from the part of the superior temporal sulcus that extends anterior to the central sulcus. Area 45B also receives input from visual association cortex that is not observed in area 44. The results have provided a clarification of the relative connections of areas 44 and 45B of the ventrolateral frontal region which, in the human brain, subserves certain aspects of language processing. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Default network connectivity in medial temporal lobe amnesia.

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    Hayes, Scott M; Salat, David H; Verfaellie, Mieke

    2012-10-17

    There is substantial overlap between the brain regions supporting episodic memory and the default network. However, in humans, the impact of bilateral medial temporal lobe (MTL) damage on a large-scale neural network such as the default mode network is unknown. To examine this issue, resting fMRI was performed with amnesic patients and control participants. Seed-based functional connectivity analyses revealed robust default network connectivity in amnesia in cortical default network regions such as medial prefrontal cortex, posterior medial cortex, and lateral parietal cortex, as well as evidence of connectivity to residual MTL tissue. Relative to control participants, decreased posterior cingulate cortex connectivity to MTL and increased connectivity to cortical default network regions including lateral parietal and medial prefrontal cortex were observed in amnesic patients. In contrast, somatomotor network connectivity was intact in amnesic patients, indicating that bilateral MTL lesions may selectively impact the default network. Changes in default network connectivity in amnesia were largely restricted to the MTL subsystem, providing preliminary support from MTL amnesic patients that the default network can be fractionated into functionally and structurally distinct components. To our knowledge, this is the first examination of the default network in amnesia.

  13. Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

    Directory of Open Access Journals (Sweden)

    Peter J Fried

    Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

  14. Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

    African Journals Online (AJOL)

    SA Journal of Radiology ... Magnetic resonance imaging (MRI) has been associated with either diffuse polymicrogyria around the entire extent of the sylvian fissure or in the posterior aspects of the parietal regions, in which case it is called posterior parietal ... This article discusses the possible embryological origin of these

  15. Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

    Science.gov (United States)

    Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

    2015-07-21

    The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

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

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    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.

  17. A case of luftsichel sign for left upper lobe collapse

    Directory of Open Access Journals (Sweden)

    Erden Erol Ünlüer

    2015-01-01

    Full Text Available The differential diagnosis of dyspnea in Emergency Department (ED patients is broad and atelectasis is one of the differentials among these. We present a 29-year-old women presented to our ED for evaluation of shortness of breath. On her chest examination, air entry and breath sounds were diminished on the left side but normal on the right. A posteroanterior chest radiograph showed radioluscent area in the upper zone of the left lung, around the aortic arch and also hyperdens area neighbouring this, like covered by a veil. Luftsichel sign together with this hiperdensity were consistent with the diagnose of left lung upper lobe collapse. The Luftsichel sign represents the hyperexpanded superior segment of the left lower lobe interposed between the atelectatic left upper lobe and aortic arch. Patient was discharged to home with chest physiotherapy and breathing exercises together with analgesic prescreption.

  18. Temporal lobe origin is common in patients who have undergone epilepsy surgery for hypermotor seizures.

    Science.gov (United States)

    Arain, Amir M; Azar, Nabil J; Lagrange, Andre H; McLean, Michael; Singh, Pradumna; Sonmezturk, Hasan; Konrad, Peter; Neimat, Joseph; Abou-Khalil, Bassel

    2016-11-01

    Hypermotor seizures are most often reported from the frontal lobe but may also have temporal, parietal, or insular origin. We noted a higher proportion of patients with temporal lobe epilepsy in our surgical cohort who had hypermotor seizures. We evaluated the anatomic localization and surgical outcome in patient with refractory hypermotor seizures who had epilepsy surgery in our center. We identified twenty three patients with refractory hypermotor seizures from our epilepsy surgery database. We analyzed demographics, presurgical evaluation including semiology, MRI, PET scan, interictal/ictal scalp video-EEG, intracranial recording, and surgical outcomes. We evaluated preoperative variables as predictors of outcome. Most patients (65%) had normal brain MRI. Intracranial EEG was required in 20 patients (86.9%). Based on the presurgical evaluation, the resection was anterior temporal in fourteen patients, orbitofrontal in four patients, cingulate in four patients, and temporoparietal in one patient. The median duration of follow-up after surgery was 76.4months. Fourteen patients (60%) had been seizure free at the last follow up while 3 patients had rare disabling seizures. Hypermotor seizures often originated from the temporal lobe in this series of patients who had epilepsy surgery. This large proportion of temporal lobe epilepsy may be the result of a selection bias, due to easier localization and expected better outcome in temporal lobe epilepsy. With extensive presurgical evaluation, including intracranial EEG when needed, seizure freedom can be expected in the majority of patients. Copyright © 2016. Published by Elsevier Inc.

  19. Abnormal parietal function in conversion paresis.

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    Marije van Beilen

    Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

  20. Let's inhibit our excitement: the relationships between Stroop, behavioral disinhibition, and the frontal lobes.

    Science.gov (United States)

    Heflin, Lara H; Laluz, Victor; Jang, Jung; Ketelle, Robin; Miller, Bruce L; Kramer, Joel H

    2011-09-01

    The Stroop (Stroop, 1935) is a frequently used neuropsychological test, with poor performance typically interpreted as indicative of disinhibition and frontal lobe damage. This study tested those interpretations by examining relationships between Stroop performance, behavioral disinhibition, and frontal lobe atrophy. Participants were 112 patients with mild cognitive impairment or dementia, recruited through UCSF's Memory and Aging Center. Participants received comprehensive dementia evaluations including structural MRI, neuropsychological testing, and informant interviews. Freesurfer, a semiautomated parcellation program, was used to analyze 1.5T MRI scans. Behavioral disinhibition was measured using the Neuropsychiatric Inventory (Cummings, 1997; Cummings et al., 1994) Disinhibition Scale. The sample (n = 112) mean age was 65.40 (SD = 8.60) years, education was 16.64 (SD = 2.54) years, and Mini-Mental State Examination (MMSE; Folstein et al., 1975) was 26.63 (SD = 3.32). Hierarchical linear regressions were used for data analysis. Controlling for age, MMSE, and color naming, Stroop performance was not significantly associated with disinhibition (β = 0.01, ΔR² = 0.01, p = .29). Hierarchical regressions controlling for age, MMSE, color naming, intracranial volume, and temporal and parietal lobes, examined whether left or right hemisphere regions predict Stroop performance. Bilaterally, parietal lobe atrophy best predicted poorer Stroop (left: β = 0.0004, ΔR² = 0.02, p = .002; right: β = 0.0004, ΔR² = 0.02, p = .002). Of frontal regions, only dorsolateral prefrontal cortex atrophy predicted poorer Stroop (β = 0.001, ΔR² = 0.01, p = .03); left and right anterior cingulate cortex atrophy predicted better Stroop (left: β = -0.003, ΔR² = 0.01, p = .02; right: β = -0.004, ΔR² = 0.01, p = .02). These findings suggest Stroop performance is a poor measure of behavioral disinhibition and frontal lobe atrophy even among a relatively high-risk population

  1. Functional interaction between right parietal and bilateral frontal cortices during visual search tasks revealed using functional magnetic imaging and transcranial direct current stimulation.

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    Amanda Ellison

    Full Text Available The existence of a network of brain regions which are activated when one undertakes a difficult visual search task is well established. Two primary nodes on this network are right posterior parietal cortex (rPPC and right frontal eye fields. Both have been shown to be involved in the orientation of attention, but the contingency that the activity of one of these areas has on the other is less clear. We sought to investigate this question by using transcranial direct current stimulation (tDCS to selectively decrease activity in rPPC and then asking participants to perform a visual search task whilst undergoing functional magnetic resonance imaging. Comparison with a condition in which sham tDCS was applied revealed that cathodal tDCS over rPPC causes a selective bilateral decrease in frontal activity when performing a visual search task. This result demonstrates for the first time that premotor regions within the frontal lobe and rPPC are not only necessary to carry out a visual search task, but that they work together to bring about normal function.

  2. Determinants of brain metabolism changes in mesial temporal lobe epilepsy.

    Science.gov (United States)

    Chassoux, Francine; Artiges, Eric; Semah, Franck; Desarnaud, Serge; Laurent, Agathe; Landre, Elisabeth; Gervais, Philippe; Devaux, Bertrand; Helal, Ourkia Badia

    2016-06-01

    To determine the main factors influencing metabolic changes in mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS). We prospectively studied 114 patients with MTLE (62 female; 60 left HS; 15- to 56-year-olds) with (18) F-fluorodeoxyglucose-positron emission tomography and correlated the results with the side of HS, structural atrophy, electroclinical features, gender, age at onset, epilepsy duration, and seizure frequency. Imaging processing was performed using statistical parametric mapping. Ipsilateral hypometabolism involved temporal (mesial structures, pole, and lateral cortex) and extratemporal areas including the insula, frontal lobe, perisylvian regions, and thalamus, more extensively in right HS (RHS). A relative increase of metabolism (hypermetabolism) was found in the nonepileptic temporal lobe and in posterior areas bilaterally. Voxel-based morphometry detected unilateral hippocampus atrophy and gray matter concentration decrease in both frontal lobes, more extensively in left HS (LHS). Regardless of the structural alterations, the topography of hypometabolism correlated strongly with the extent of epileptic networks (mesial, anterior-mesiolateral, widespread mesiolateral, and bitemporal according to the ictal spread), which were larger in RHS. Notably, widespread perisylvian and bitemporal hypometabolism was found only in RHS. Mirror hypermetabolism was grossly proportional to the hypometabolic areas, coinciding partly with the default mode network. Gender-related effect was significant mainly in the contralateral frontal lobe, in which metabolism was higher in female patients. Epilepsy duration correlated with the contralateral temporal metabolism, positively in LHS and negatively in RHS. Opposite results were found with age at onset. High seizure frequency correlated negatively with the contralateral metabolism in LHS. Epileptic networks, as assessed by electroclinical correlations, appear to be the main determinant of

  3. Intrinsic controls on the range of volumes, morphologies, and dimensions of submarine lobes

    Science.gov (United States)

    Prélat, A.; Covault, J. A.; Hodgson, D. M.; Fildani, A.; Flint, S. S.

    2010-12-01

    Submarine lobe dimensions from six different systems are compared: 1) the exhumed Permian Fan 3 lobe complex of the Tanqua Karoo, South Africa; 2) the modern Amazon fan channel-mouth lobe complex, offshore Brazil; 3) a portion of the modern distal Zaïre fan, offshore Angola/Congo; 4) a Pleistocene fan of the Kutai basin, subsurface offshore Indonesia; 5) the modern Golo system, offshore east Corsica, France; and 6) a shallow subsurface lobe complex , offshore Nigeria. These six systems have significantly different source-to-sink configurations (shelf dimension and slope topography), sediment supply characteristics (available grain size range and supply rate), tectonic settings, (palaeo) latitude, and delivery systems. Despite these differences, lobe deposits share similar geometric and dimensional characteristics. Lobes are grouped into two distinct populations of geometries that can be related to basin floor topography. The first population corresponds to areally extensive but thin lobes (average width 14 km × length 35 km × thickness 12 m) that were deposited onto low relief basin floor areas. Examples of such systems include the Tanqua Karoo, the Amazon, and the Zaïre systems. The second population corresponds to areally smaller but thicker lobes (average width 5 km × length 8 km × thickness 30 m) that were deposited into settings with higher amplitude of relief, like in the Corsican trough, the Kutai basin, and offshore Nigeria. The two populations of lobe types, however, share similar volumes (a narrow range around 1 or 2 km 3), which suggests that there is a control to the total volume of sediment that individual lobes can reach before they shift to a new locus of deposition. This indicates that the extrinsic processes control the number of lobes deposited per unit time rather than their dimensions. Two alternative hypotheses are presented to explain the similarities in lobe volumes calculated from the six very different systems. The first states that

  4. The role of parietal cortex in the formation of colour and motion based concepts

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    Samuel William Cheadle

    2014-07-01

    Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

  5. Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

    Science.gov (United States)

    Chan, Annie W-Y; Baker, Chris I

    2015-01-28

    Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

  6. 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

  7. Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

    Science.gov (United States)

    Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

    2013-03-01

    In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Occipital lobe infarctions are different

    OpenAIRE

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

    2007-01-01

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

  9. Intradiploic encephalocele of the left parietal bone: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok [Myongji St. Mary' s Hospital, Seoul (Korea, Republic of)

    2015-06-15

    Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood.

  10. Intradiploic encephalocele of the left parietal bone: A case report

    International Nuclear Information System (INIS)

    Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok

    2015-01-01

    Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood

  11. Parietal cortex and representation of the mental Self

    DEFF Research Database (Denmark)

    Lou, Hans C; Luber, Bruce; Crupain, Michael

    2004-01-01

    For a coherent and meaningful life, conscious self-representation is mandatory. Such explicit "autonoetic consciousness" is thought to emerge by retrieval of memory of personally experienced events ("episodic memory"). During episodic retrieval, functional imaging studies consistently show....... The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self...

  12. The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

    Science.gov (United States)

    Hales, J. B.

    2011-01-01

    The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  14. Giant lipoma arising from deep lobe of the parotid gland

    Directory of Open Access Journals (Sweden)

    Hsu Ying-Che

    2006-06-01

    Full Text Available Abstract Background Lipomas are common benign soft tissue neoplasms but they are found very rarely in the deep lobe of parotid gland. Surgical intervention in these tumors is challenging because of the proximity of the facial nerve, and thus knowledge of the anatomy and meticulous surgical technique are essential. Case presentation A 71-year-old female presented with a large asymptomatic mass, which had occupied the left facial area for over the past fifteen years, and she requested surgical excision for a cosmetically better facial appearance. The computed tomography (CT scan showed a well-defined giant lipoma arising from the left deep parotid gland. The lipoma was successfully enucleated after full exposure and mobilization of the overlying facial nerve branches. The surgical specimen measured 9 × 6 cm in size, and histopathology revealed fibrolipoma. The patient experienced an uneventful recovery, with a satisfying facial contour and intact facial nerve function. Conclusion Giant lipomas involving the deep parotid lobe are extremely rare. The high-resolution CT scan provides an accurate and cost-effective preoperative investigative method. Surgical management of deep lobe lipoma should be performed by experienced surgeons due to the need for meticulous dissection of the facial nerve branches. Superficial parotidectomy before deep lobe lipoma removal may be unnecessary in selected cases because preservation of the superficial lobe may contribute to a better aesthetic and functional result.

  15. Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

    Science.gov (United States)

    Kaas, Jon H; Stepniewska, Iwona

    2016-02-15

    Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

  16. Are the dimensions of submarine lobe systems independent of allogenic factors?

    Science.gov (United States)

    Prélat, A.; Covault, J. A.; Hodgson, D. M.; Fildani, A.; Flint, S. S.

    2010-05-01

    Submarine lobe dimensions from six different systems are compared: 1) the exhumed Permian Fan 3 lobe complex of the Tanqua Karoo, South Africa; 2) the modern Amazon fan channel-mouth lobe complex, offshore Brazil; 3) a portion of the modern distal Zaïre fan, offshore Angola / Congo; 4) a Pleistocene fan of the Kutai Basin, subsurface offshore Indonesia; 5) the modern Golo system, offshore east Corsica, France; and 6) a lobe complex deposited in the shallow subsurface, offshore Nigeria. These six systems have significantly different source-to-sink configurations (shelf dimension and slope topography), sediment supply characteristics (calibre and rate), tectonic settings, (palaeo) latitude, and delivery systems. Despite these differences, the lobe deposits share similar geometric and dimensional characteristics. Lobes are grouped into two distinct populations of geometries that can be related to basin-floor topography. The first population corresponds to areally extensive but thin lobes (average width 14 km × length 35 km × thickness 12 m) that were deposited onto low relief basin floor areas, like the Tanqua Karoo, the Amazon and the Zaïre systems. The second population corresponds to areally smaller but thicker lobes (average width 5 km × length 8 km × thickness 30 m) that were deposited into settings with higher amplitude of relief, like in the Corsican trough, the Kutai basin, and offshore Nigeria. Basin floor topography confining the lobes can be very subtle, and only occur on one side of the system. The two populations of lobe types, however, share similar volumes, in the order of 1 or 2 km3. The largest lobes are observed in the Zaïre fan, where the average lobe volume reaches 3.3 km3 and the smallest lobes are observed in the Corsican trough where the average lobe volume is 0.4 km3. This variation in lobe volume is minor when compared to the variation observed in present-day up-dip drainage systems, which provide sediment to the deep-water depositional

  17. Usefulness of PET in non-lesional temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Bertuluchi, M.; Arganaraz, R.; Buznick, J.; Pomata, H.

    2011-01-01

    Objective. To evaluate the usefulness of PET in patients with refractory non-lesional temporal lobe epilepsy. Material and methods. We present three patients with features of temporal lobe epilepsy refractory to medication, where high definition MRI was normal. Results. These patients had PET hypometabolism in the temporal areas related to clinical and neurophysiological findings. Two of these patients were implanted with subdural grids to confirm the diagnosis and the third was operated directly based on the findings of PET. Encourage the presentation of the importance in recent years is acquiring the PET. Conclusion. In those patients in clinical neurophysiology and epilepsy with suspected temporal lobe, but in the MRI images show no structural lesions, PET can play an important role defining the diagnosis. (authors)

  18. Altered Parietal Activation during Non-symbolic Number Comparison in Children with Prenatal Alcohol Exposure

    Directory of Open Access Journals (Sweden)

    Keri J. Woods

    2018-01-01

    Full Text Available Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI, we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS/partial FAS, 5 heavily exposed (HE non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years. Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS, bilateral posterior superior parietal lobules (PSPL, and left angular gyrus (left AG, using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non

  19. Anterior Temporal Lobe Morphometry Predicts Categorization Ability.

    Science.gov (United States)

    Garcin, Béatrice; Urbanski, Marika; Thiebaut de Schotten, Michel; Levy, Richard; Volle, Emmanuelle

    2018-01-01

    Categorization is the mental operation by which the brain classifies objects and events. It is classically assessed using semantic and non-semantic matching or sorting tasks. These tasks show a high variability in performance across healthy controls and the cerebral bases supporting this variability remain unknown. In this study we performed a voxel-based morphometry study to explore the relationships between semantic and shape categorization tasks and brain morphometric differences in 50 controls. We found significant correlation between categorization performance and the volume of the gray matter in the right anterior middle and inferior temporal gyri. Semantic categorization tasks were associated with more rostral temporal regions than shape categorization tasks. A significant relationship was also shown between white matter volume in the right temporal lobe and performance in the semantic tasks. Tractography revealed that this white matter region involved several projection and association fibers, including the arcuate fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. These results suggest that categorization abilities are supported by the anterior portion of the right temporal lobe and its interaction with other areas.

  20. Anterior Temporal Lobe Morphometry Predicts Categorization Ability

    Directory of Open Access Journals (Sweden)

    Béatrice Garcin

    2018-02-01

    Full Text Available Categorization is the mental operation by which the brain classifies objects and events. It is classically assessed using semantic and non-semantic matching or sorting tasks. These tasks show a high variability in performance across healthy controls and the cerebral bases supporting this variability remain unknown. In this study we performed a voxel-based morphometry study to explore the relationships between semantic and shape categorization tasks and brain morphometric differences in 50 controls. We found significant correlation between categorization performance and the volume of the gray matter in the right anterior middle and inferior temporal gyri. Semantic categorization tasks were associated with more rostral temporal regions than shape categorization tasks. A significant relationship was also shown between white matter volume in the right temporal lobe and performance in the semantic tasks. Tractography revealed that this white matter region involved several projection and association fibers, including the arcuate fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. These results suggest that categorization abilities are supported by the anterior portion of the right temporal lobe and its interaction with other areas.

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

    Science.gov (United States)

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

    2017-03-15

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

  2. Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

    Science.gov (United States)

    Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

    2017-06-09

    Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2013-09-01

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

  4. Bilateral parietal extradural metastatic ewing's sarcoma simulating acute epidural hematoma

    International Nuclear Information System (INIS)

    Aslam, E.; Imran, M.; Faridi, N.M.

    2006-01-01

    Sarcomas usually metastasize to lugs. The following case report describes an unusual metastasis of Ewing's sarcoma to extradural parietal region bilaterally. The primary was found at lower end of ulna. (author)

  5. Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

    Science.gov (United States)

    Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

    2013-10-16

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

  6. Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

    Science.gov (United States)

    Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

    2013-01-01

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

  7. Attenuating illusory binding with TMS of the right parietal cortex

    OpenAIRE

    Esterman, Michael; Verstynen, Timothy; Robertson, Lynn C.

    2007-01-01

    A number of neuroimaging and neuropsychology studies have implicated various regions of parietal cortex as playing a critical role in the binding of color and form into conjunctions. The current study investigates the role of two such regions by examining how parietal transcranial magnetic stimulation (TMS) influences binding errors known as ‘illusory conjunctions.’ Participants made fewer binding errors after 1 Hz rTMS of the right intraparietal sulcus (IPS), while basic perception of featur...

  8. Brain mapping of epileptic activity in a case of idiopathic occipital lobe epilepsy (Panayiotopoulos syndrome).

    Science.gov (United States)

    Leal, Alberto J R; Nunes, Sofia; Martins, António; Secca, Mário Forjaz; Jordão, Constança

    2007-06-01

    The Panayiotopoulos type of occipital lobe epilepsy has generated great interest, but the particular brain areas involved in the peculiar seizure manifestations have not been established. We studied a patient with the syndrome, using high-resolution EEG and simultaneous EEG and functional magnetic resonance imaging (fMRI). Resolution of the scalp EEG was improved using a realistic spline Laplacian algorithm, and produced a complex distribution of current sinks and sources over the occipital lobe. The spike-related blood oxygen level dependent (BOLD) effect was multifocal, with clusters in lateral and inferior occipital lobe and lateral and anterior temporal lobe. We also performed regional dipole seeding in BOLD clusters to determine their relative contribution to generation of scalp spikes. The integrated model of the neurophysiologic and vascular data strongly suggests that the epileptic activity originates in the lateral occipital area, spreading to the occipital pole and lateral temporal lobe.

  9. Multimodal FMRI resting-state functional connectivity in granulin mutations: the case of fronto-parietal dementia.

    Directory of Open Access Journals (Sweden)

    Enrico Premi

    Full Text Available BACKGROUND: Monogenic dementias represent a great opportunity to trace disease progression from preclinical to symptomatic stages. Frontotemporal Dementia related to Granulin (GRN mutations presents a specific framework of brain damage, involving fronto-temporal regions and long inter-hemispheric white matter bundles. Multimodal resting-state functional MRI (rs-fMRI is a promising tool to carefully describe disease signature from the earliest disease phase. OBJECTIVE: To define local connectivity alterations in GRN related pathology moving from the presymptomatic (asymptomatic GRN mutation carriers to the clinical phase of the disease (GRN- related Frontotemporal Dementia. METHODS: Thirty-one GRN Thr272fs mutation carriers (14 patients with Frontotemporal Dementia and 17 asymptomatic carriers and 38 healthy controls were recruited. Local connectivity measures (Regional Homogeneity (ReHo, Fractional Amplitude of Low Frequency Fluctuation (fALFF and Degree Centrality (DC were computed, considering age and gender as nuisance variables as well as the influence of voxel-level gray matter atrophy. RESULTS: Asymptomatic GRN carriers had selective reduced ReHo in the left parietal region and increased ReHo in frontal regions compared to healthy controls. Considering Frontotemporal Dementia patients, all measures (ReHo, fALFF and DC were reduced in inferior parietal, frontal lobes and posterior cingulate cortex. Considering GRN mutation carriers, an inverse correlation with age in the posterior cingulate cortex, inferior parietal lobule and orbitofrontal cortex was found. CONCLUSIONS: GRN pathology is characterized by functional brain network alterations even decades before the clinical onset; they involve the parietal region primarily and then spread to the anterior regions of the brain, supporting the concept of molecular nexopathies.

  10. Automatic extraction analysis of the anatomical functional area for normal brain 18F-FDG PET imaging

    International Nuclear Information System (INIS)

    Guo Wanhua; Jiang Xufeng; Zhang Liying; Lu Zhongwei; Li Peiyong; Zhu Chengmo; Zhang Jiange; Pan Jiapu

    2003-01-01

    Using self-designed automatic extraction software of brain functional area, the grey scale distribution of 18 F-FDG imaging and the relationship between the 18 F-FDG accumulation of brain anatomic function area and the 18 F-FDG injected dose, the level of glucose, the age, etc., were studied. According to the Talairach coordinate system, after rotation, drift and plastic deformation, the 18 F-FDG PET imaging was registered into the Talairach coordinate atlas, and then the average gray value scale ratios between individual brain anatomic functional area and whole brain area was calculated. Further more the statistics of the relationship between the 18 F-FDG accumulation of every brain anatomic function area and the 18 F-FDG injected dose, the level of glucose and the age were tested by using multiple stepwise regression model. After images' registration, smoothing and extraction, main cerebral cortex of the 18 F-FDG PET brain imaging can be successfully localized and extracted, such as frontal lobe, parietal lobe, occipital lobe, temporal lobe, cerebellum, brain ventricle, thalamus and hippocampus. The average ratios to the inner reference of every brain anatomic functional area were 1.01 ± 0.15. By multiple stepwise regression with the exception of thalamus and hippocampus, the grey scale of all the brain functional area was negatively correlated to the ages, but with no correlation to blood sugar and dose in all areas. To the 18 F-FDG PET imaging, the brain functional area extraction program could automatically delineate most of the cerebral cortical area, and also successfully reflect the brain blood and metabolic study, but extraction of the more detailed area needs further investigation

  11. Occipital lobe seizures and epilepsies.

    Science.gov (United States)

    Adcock, Jane E; Panayiotopoulos, Chrysostomos P

    2012-10-01

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

  12. Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

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    Michael T Lippert

    Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

  13. Observing complex action sequences: The role of the fronto-parietal mirror neuron system.

    Science.gov (United States)

    Molnar-Szakacs, Istvan; Kaplan, Jonas; Greenfield, Patricia M; Iacoboni, Marco

    2006-11-15

    A fronto-parietal mirror neuron network in the human brain supports the ability to represent and understand observed actions allowing us to successfully interact with others and our environment. Using functional magnetic resonance imaging (fMRI), we wanted to investigate the response of this network in adults during observation of hierarchically organized action sequences of varying complexity that emerge at different developmental stages. We hypothesized that fronto-parietal systems may play a role in coding the hierarchical structure of object-directed actions. The observation of all action sequences recruited a common bilateral network including the fronto-parietal mirror neuron system and occipito-temporal visual motion areas. Activity in mirror neuron areas varied according to the motoric complexity of the observed actions, but not according to the developmental sequence of action structures, possibly due to the fact that our subjects were all adults. These results suggest that the mirror neuron system provides a fairly accurate simulation process of observed actions, mimicking internally the level of motoric complexity. We also discuss the results in terms of the links between mirror neurons, language development and evolution.

  14. Exogenous vs. endogenous attention: Shifting the balance of fronto-parietal activity.

    Science.gov (United States)

    Meyer, Kristin N; Du, Feng; Parks, Emily; Hopfinger, Joseph B

    2018-03-01

    Despite behavioral and electrophysiological evidence for dissociations between endogenous (voluntary) and exogenous (reflexive) attention, fMRI results have yet to consistently and clearly differentiate neural activation patterns between these two types of attention. This study specifically aimed to determine whether activity in the dorsal fronto-parietal network differed between endogenous and exogenous conditions. Participants performed a visual discrimination task in endogenous and exogenous attention conditions while undergoing fMRI scanning. Analyses revealed robust and bilateral activation throughout the dorsal fronto-parietal network for each condition, in line with many previous results. In order to investigate possible differences in the balance of neural activity within this network with greater sensitivity, a priori regions of interest (ROIs) were selected for analysis, centered on the frontal eye fields (FEF) and intraparietal sulcus (IPS) regions identified in previous studies. The results revealed a significant interaction between region, condition, and hemisphere. Specifically, in the left hemisphere, frontal areas were more active than parietal areas, but only during endogenous attention. Activity in the right hemisphere, in contrast, remained relatively consistent for these regions across conditions. Analysis of this activity over time indicates that this left-hemispheric regional imbalance is present within the FEF early, at 3-6.5 s post-stimulus presentation, whereas a regional imbalance in the exogenous condition is not evident until 6.5-8 s post-stimulus presentation. Overall, our results provide new evidence that although the dorsal fronto-parietal network is indeed associated with both types of attentional orienting, regions of the network are differentially engaged over time and across hemispheres depending on the type of attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

    Science.gov (United States)

    Greene, Ciara M; Flannery, Oliver; Soto, David

    2014-12-01

    The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

  16. Fronto-parietal coding of goal-directed actions performed by artificial agents.

    Science.gov (United States)

    Kupferberg, Aleksandra; Iacoboni, Marco; Flanagin, Virginia; Huber, Markus; Kasparbauer, Anna; Baumgartner, Thomas; Hasler, Gregor; Schmidt, Florian; Borst, Christoph; Glasauer, Stefan

    2018-03-01

    With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment. © 2017 Wiley Periodicals, Inc.

  17. CT evaluation of decrease in attenuation in the superior segment of the left lower lobe

    International Nuclear Information System (INIS)

    Inaoka, Tsutomu; Takahashi, Koji; Ono, Hidetoshi

    2003-01-01

    We occasionally see decrease in attenuation in the superior segment of the left lower lobe on normal chest CT and notice that this finding could be seen in elder population. Then, we assessed the frequency, age distribution and cause of decrease in attenuation in the superior segment of the left lower lobe. Chest CT scans of 246 patients without lung or cardiac disorders were retrospectively reviewed. Segmental low attenuation area in the superior segment of the left lower lobe was identified in 12 patients (4.9%), which were 65-92 years old with mean age of 77.2 years old. In all of them, chest CT demonstrated that the tortuous descending aorta compressed directly the superior segmental bronchus of the left lower lobe. It is concluded that the lateral tortuousity of the descending aorta could cause decrease in attenuation in the superior segment of the left lower lobe. (author)

  18. Meta-analysis: how does posterior parietal cortex contribute to reasoning?

    Science.gov (United States)

    Wendelken, Carter

    2015-01-01

    Reasoning depends on the contribution of posterior parietal cortex (PPC). But PPC is involved in many basic operations—including spatial attention, mathematical cognition, working memory, long-term memory, and language—and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: (1) reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing; (2) reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC; and (3) reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest (ROI). Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL). Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific to

  19. Meta-analysis: How does posterior parietal cortex contribute to reasoning?

    Directory of Open Access Journals (Sweden)

    Carter eWendelken

    2015-01-01

    Full Text Available Reasoning depends on the contribution of posterior parietal cortex (PPC. But PPC is involved in many basic operations -- including spatial attention, mathematical cognition, working memory, long-term memory, and language -- and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: 1 reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing, 2 reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC, and 3 reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest. Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL. Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific

  20. Functional segregation and integration within fronto-parietal networks.

    Science.gov (United States)

    Parlatini, Valeria; Radua, Joaquim; Dell'Acqua, Flavio; Leslie, Anoushka; Simmons, Andy; Murphy, Declan G; Catani, Marco; Thiebaut de Schotten, Michel

    2017-02-01

    Experimental data on monkeys and functional studies in humans support the existence of a complex fronto-parietal system activating for cognitive and motor tasks, which may be anatomically supported by the superior longitudinal fasciculus (SLF). Advanced tractography methods have recently allowed the separation of the three branches of the SLF but are not suitable for their functional investigation. In order to gather comprehensive information about the functional organisation of these fronto-parietal connections, we used an innovative method, which combined tractography of the SLF in the largest dataset so far (129 participants) with 14 meta-analyses of functional magnetic resonance imaging (fMRI) studies. We found that frontal and parietal functions can be clustered into a dorsal spatial/motor network associated with the SLF I, and a ventral non-spatial/motor network associated with the SLF III. Further, all the investigated functions activated a middle network mostly associated with the SLF II. Our findings suggest that dorsal and ventral fronto-parietal networks are segregated but also share regions of activation, which may support flexible response properties or conscious processing. In sum, our novel combined approach provided novel findings on the functional organisation of fronto-parietal networks, and may be successfully applied to other brain connections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. 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)

  2. Prediction of Reach Goals in Depth and Direction from the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Matteo Filippini

    2018-04-01

    Full Text Available Summary: The posterior parietal cortex is well known to mediate sensorimotor transformations during the generation of movement plans, but its ability to control prosthetic limbs in 3D environments has not yet been fully demonstrated. With this aim, we trained monkeys to perform reaches to targets located at various depths and directions and tested whether the reach goal position can be extracted from parietal signals. The reach goal location was reliably decoded with accuracy close to optimal (>90%, and this occurred also well before movement onset. These results, together with recent work showing a reliable decoding of hand grip in the same area, suggest that this is a suitable site to decode the entire prehension action, to be considered in the development of brain-computer interfaces. : Filippini et al. show that it is possible to use parietal cortex activity to predict in which direction the arm will move and how far it will reach. This opens up the possibility of neural prostheses that can accurately guide reach and grasp using signals from this part of the brain. Keywords: neuroprosthetics, offline neural decoding, reaching in depth, monkey, V6A, machine learning, visuomotor transformations, hand guidance, prehension, robotics

  3. Structural and functional evaluation of cortical motor areas in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Cosottini, Mirco; Pesaresi, Ilaria; Piazza, Selina; Diciotti, Stefano; Cecchi, Paolo; Fabbri, Serena; Carlesi, Cecilia; Mascalchi, Mario; Siciliano, Gabriele

    2012-03-01

    The structural and functional data gathered with Magnetic Resonance Imaging (MRI) techniques about the brain cortical motor damage in Amyotrophic Lateral Sclerosis (ALS) are controversial. In fact some structural MRI studies showed foci of gray matter (GM) atrophy in the precentral gyrus, even in the early stage, while others did not. Most functional MRI (fMRI) studies in ALS reported hyperactivation of extra-primary motor cortices, while contradictory results were obtained on the activation of the primary motor cortex. We aimed to investigate the cortical motor circuitries in ALS patients by a combined structural and functional approach. Twenty patients with definite ALS and 16 healthy subjects underwent a structural examination with acquisition of a 3D T1-weighted sequence and fMRI examination during a maximal force handgrip task executed with the right-hand, the left-hand and with both hands simultaneously. The T1-weighted images were analyzed with Voxel-Based Morphometry (VBM) that showed several clusters of reduced cortical GM in ALS patients compared to controls including the pre and postcentral gyri, the superior, middle and inferior frontal gyri, the supplementary motor area, the superior and inferior parietal cortices and the temporal lobe, bilaterally but more extensive on the right side. In ALS patients a significant hypoactivation of the primary sensory motor cortex and frontal dorsal premotor areas as compared to controls was observed. The hypoactivated areas matched with foci of cortical atrophy demonstrated by VBM. The fMRI analysis also showed an enhanced activation in the ventral premotor frontal areas and in the parietal cortex pertaining to the fronto-parietal motor circuit which paralleled with disease progression rate and matched with cortical regions of atrophy. The hyperactivation of the fronto-parietal circuit was asymmetric and prevalent in the left hemisphere. VBM and fMRI identified structural and functional markers of an extended

  4. Frontal lobe epilepsy may present as myoclonic seizures.

    Science.gov (United States)

    Cho, Yong Won; Yi, Sang Doe; Motamedi, Gholam K

    2010-04-01

    We describe a patient with seizures arising from right anterior-inferior frontal lobe presenting as myoclonic epilepsy. A 19-year-old man had experienced frequent paroxysmal bilateral myoclonic jerks involving his upper arms, shoulders, neck, and upper trunk since the age of 10. His baseline EEG showed intermittent right frontal spikes, and his ictal EEG showed rhythmic sharp theta discharges in the same area. MRI revealed cortical dysplasia in the right inferior frontal gyrus, and ictal-interictal SPECT analysis by SPM showed increased signal abnormality in this region. Diffusion tensor imaging (DTI) showed defects in fasciculi in the same area. These findings suggest that frontal lobe epilepsy should be considered in some patients with myoclonic seizures. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  5. Matrix Metalloproteinase-9 Expression Is Enhanced in Renal Parietal Epithelial Cells of Zucker Diabetic Fatty Rats and Is Induced by Albumin in In Vitro Primary Parietal Cell Culture

    Science.gov (United States)

    Zhang, Yuanyuan; George, Jasmine; Li, Yun; Olufade, Rebecca; Zhao, Xueying

    2015-01-01

    As a subfamily of matrix metalloproteinases (MMPs), gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs) expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin) in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml) for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK) in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive diabetic nephropathy

  6. Haptically guided grasping. FMRI shows right-hemisphere parietal stimulus encoding, and bilateral dorso-ventral parietal gradients of object- and action-related processing during grasp execution

    Directory of Open Access Journals (Sweden)

    Mattia eMarangon

    2016-01-01

    Full Text Available The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks. None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

  7. Significance of parietal projection in radiosotope scintigraphy of the brain

    International Nuclear Information System (INIS)

    Fomchenkov, E.P.

    1978-01-01

    The diagnostic value of the isotope scintigraphy of the brain in the parieal projection with the change of the dip angle of the gamma-chamber detector to the plane of the physiological horizontal was revealed. The observation was made on 100 patients with suspected presence of the volumetric process of the brain. Three variants of placing were studied: the parietal projection - standard (collimator plane parallel to the plane of physiological horizontal and strictly perpendicular to the sagittal plane); the placing with an angle of 30 deg between the detector plane and the physiological horizontal, opened at the front (posterio-parietal); placing with an angle of 30 deg between the detector plane and the physiological horizontal opened at the back (anterio-parietal). A comparative analysis of scintigrams with focal processes of the brain showed the largest informativeness of the proposed modification of the parietal projection in the form of a change of the dip angle of the gamma-chamber detector plane to the plane of the physiological horizontal opened at the back; this makes it possible to reveal more thoroughly the focus of the increased, pathological accumulation of the isotope in different parts of the skull, where the use of as standard placing is of small informativeness

  8. Subtotal ablation of parietal epithelial cells induces crescent formation.

    NARCIS (Netherlands)

    Sicking, E.M.; Fuss, A.; Uhlig, S.; Jirak, P.; Dijkman, H.; Wetzels, J.; Engel, D.R.; Urzynicok, T.; Heidenreich, S.; Kriz, W.; Kurts, C.; Ostendorf, T.; Floege, J.; Smeets, B.; Moeller, M.J.

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established

  9. Parietal epithelial cells and podocytes in glomerular diseases

    NARCIS (Netherlands)

    Smeets, B.; Moeller, M.J.

    2012-01-01

    In recent years, it has become apparent that parietal epithelial cells (PECs) play an important role within the renal glomerulus, in particular in diseased conditions. In this review, we examine current knowledge about the role of PECs and their interactions with podocytes in development and under

  10. Parietal cells-new perspectives in glomerular disease

    NARCIS (Netherlands)

    Miesen, L.; Steenbergen, E.; Smeets, B.

    2017-01-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and

  11. Neuronal synchronization in human parietal cortex during saccade planning

    NARCIS (Netherlands)

    Werf, J. van der; Buchholz, V.N.; Jensen, O.; Medendorp, W.P.

    2009-01-01

    Neuropsychological and neuroimaging studies have implicated the human posterior parietal cortex (PPC) in sensorimotor integration and saccade planning However, the temporal dynamics of the underlying physiology and its relationship to observations in non-human primates have been difficult to pin

  12. Parietal epithelial cells: their role in health and disease.

    Science.gov (United States)

    Romagnani, Paola

    2011-01-01

    Parietal epithelial cells of Bowman's capsules were first described by Sir William Bowman in 1842 in his paper On the Structure and Use of the Malpighian Bodies of the Kidney [London, Taylor, 1842], but since then their functions have remained poorly understood. A large body of evidence has recently suggested that parietal epithelial cells represent a reservoir of renal progenitors in adult human kidney which generate novel podocytes during childhood and adolescence, and can regenerate injured podocytes. The discovery that parietal epithelial cells represent a potential source for podocyte regeneration suggests that podocyte injury can be repaired. However, recent results also suggest that an abnormal proliferative response of renal progenitors to podocyte injury can generate hyperplastic glomerular lesions that are observed in crescentic glomerulonephritis and other types of glomerular disorders. Taken together, these results establish an entirely novel view that changes the way of thinking about renal physiology and pathophysiology, and suggest that understanding how self-renewal and fate decision of parietal epithelial cells in response to podocyte injury may be perturbed or modulated will be crucial for obtaining novel tools for prevention and treatment of glomerulosclerosis. Copyright © 2011 S. Karger AG, Basel.

  13. The regenerative potential of parietal epithelial cells in adult mice

    NARCIS (Netherlands)

    Berger, K.; Schulte, K.; Boor, P.; Kuppe, C.; Kuppevelt, T.H. van; Floege, J.; Smeets, B.; Moeller, M.J.

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically

  14. Virtual lesions of the inferior parietal cortex induce fast changes of implicit religiousness/spirituality.

    Science.gov (United States)

    Crescentini, Cristiano; Aglioti, Salvatore M; Fabbro, Franco; Urgesi, Cosimo

    2014-05-01

    Religiousness and spirituality (RS) are two ubiquitous aspects of human experience typically considered impervious to scientific investigation. Nevertheless, associations between RS and frontoparietal neural activity have been recently reported. However, much less is known about whether such activity is causally involved in modulating RS or just epiphenomenal to them. Here we combined two-pulse (10 Hz) Transcranial Magnetic Stimulation (TMS) with a novel, ad-hoc developed RS-related, Implicit Association Test (IAT) to investigate whether implicit RS representations, although supposedly rather stable, can be rapidly modified by a virtual lesion of inferior parietal lobe (IPL) and dorsolateral prefrontal cortex (DLPFC). A self-esteem (SE) IAT, focused on self-concepts nonrelated to RS representations, was developed as control. A specific increase of RS followed inhibition of IPL demonstrating its causative role in inducing fast plastic changes of religiousness/spirituality. In contrast, DLPFC inhibition had more widespread effects probably reflecting a general role in the acquisition or maintenance of task-rules or in controlling the expression of self-related representations not specific to RS. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Excitatory stimulation of the right inferior parietal cortex lessens implicit religiousness/spirituality.

    Science.gov (United States)

    Crescentini, Cristiano; Di Bucchianico, Marilena; Fabbro, Franco; Urgesi, Cosimo

    2015-04-01

    Although religiousness and spirituality (RS) are considered two fundamental constituents of human life, neuroscientific investigation has long avoided the study of their neurocognitive basis. Nevertheless, recent investigations with brain imaging and brain damaged patients, and more recently with brain stimulation methods, have documented important associations between RS beliefs and experiences and frontoparietal neural activity. In this study, we further investigated how individuals' implicit RS self-representations can be modulated by changes in right inferior parietal lobe (IPL) excitability, a key region associated to RS. To this end, we combined continuous theta burst stimulation (cTBS), intermittent TBS (iTBS), and sham TBS with RS-related, Implicit Association Test (IAT) and with a control self-esteem (SE) IAT in a group of fourteen healthy adult individuals. A specific decrease of implicit RS, as measured with the IAT effect, was induced by increasing IPL excitability with iTBS; conversely cTBS, which is supposedly inhibitory, left participants' implicit RS unchanged. The performance in the control SE-IAT was left unchanged by any TBS stimulation. These data showed the causative role of right IPL functional state in mediating plastic changes of implicit RS. Implications of these results are also discussed in the light of the variability of behavioral effects associated with TBS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Agnosia for mirror stimuli: a new case report with a small parietal lesion.

    Science.gov (United States)

    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

    2014-11-01

    Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects matched for age. This test revealed an agnosia for mirror stimuli. Brain imaging showed a small right occipitoparietal hematoma, encompassing the extrastriate cortex adjoining the inferior parietal lobe. This new case suggests that: (i) agnosia for mirror stimuli can persist for 5 years after onset and (ii) the posterior part of the right intraparietal sulcus could be critical in the cognitive process of mirror stimuli discrimination. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Parietal and temporal activity during a multimodal dance video game: an fNIRS study.

    Science.gov (United States)

    Tachibana, Atsumichi; Noah, J Adam; Bronner, Shaw; Ono, Yumie; Onozuka, Minoru

    2011-10-03

    Using functional near infrared spectroscopy (fNIRS) we studied how playing a dance video game employs coordinated activation of sensory-motor integration centers of the superior parietal lobe (SPL) and superior temporal gyrus (STG). Subjects played a dance video game, in a block design with 30s of activity alternating with 30s of rest, while changes in oxy-hemoglobin (oxy-Hb) levels were continuously measured. The game was modified to compare difficult (4-arrow), simple (2-arrow), and stepping conditions. Oxy-Hb levels were greatest with increased task difficulty. The quick-onset, trapezoidal time-course increase in SPL oxy-Hb levels reflected the on-off neuronal response of spatial orienting and rhythmic motor timing that were required during the activity. Slow-onset, bell-shaped increases in oxy-Hb levels observed in STG suggested the gradually increasing load of directing multisensory information to downstream processing centers associated with motor behavior and control. Differences in temporal relationships of SPL and STG oxy-Hb concentration levels may reflect the functional roles of these brain structures during the task period. NIRS permits insights into temporal relationships of cortical hemodynamics during real motor tasks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. Mental reversal of imagined melodies: a role for the posterior parietal cortex.

    Science.gov (United States)

    Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

    2010-04-01

    Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

  19. Prospective relations between resting-state connectivity of parietal subdivisions and arithmetic competence.

    Science.gov (United States)

    Price, Gavin R; Yeo, Darren J; Wilkey, Eric D; Cutting, Laurie E

    2018-04-01

    The present study investigates the relation between resting-state functional connectivity (rsFC) of cytoarchitectonically defined subdivisions of the parietal cortex at the end of 1st grade and arithmetic performance at the end of 2nd grade. Results revealed a dissociable pattern of relations between rsFC and arithmetic competence among subdivisions of intraparietal sulcus (IPS) and angular gyrus (AG). rsFC between right hemisphere IPS subdivisions and contralateral IPS subdivisions positively correlated with arithmetic competence. In contrast, rsFC between the left hIP1 and the right medial temporal lobe, and rsFC between the left AG and left superior frontal gyrus, were negatively correlated with arithmetic competence. These results suggest that strong inter-hemispheric IPS connectivity is important for math development, reflecting either neurocognitive mechanisms specific to arithmetic processing, domain-general mechanisms that are particularly relevant to arithmetic competence, or structural 'cortical maturity'. Stronger connectivity between IPS, and AG, subdivisions and frontal and temporal cortices, however, appears to be negatively associated with math development, possibly reflecting the ability to disengage suboptimal problem-solving strategies during mathematical processing, or to flexibly reorient task-based networks. Importantly, the reported results pertain even when controlling for reading, spatial attention, and working memory, suggesting that the observed rsFC-behavior relations are specific to arithmetic competence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. PET imaging in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Semah, F.

    2006-01-01

    The research projects on epilepsy addressed two main issues: the pathophysiology of the inter-ictal hypo-metabolism in temporal lobe epilepsy and the role of the basal ganglia in the control of seizure. Our research projects focused primarily on temporal lobe epilepsy: The pathophysiology of inter-ictal hypo-metabolism and its correlation with the epileptogenic network was investigated in patients with mesial temporal lobe epilepsy. Inter-ictal hypo-metabolism is commonly found in mesio-temporal lobe epilepsy (MTLE) but its pathophysiology remains incompletely understood. We hypothesized that metabolic changes reflect the preferential networks involved in ictal discharges. We analyzed the topography of inter-ictal hypo-metabolism according to electro-clinical patterns in 50 patients with unilateral hippocampal sclerosis (HS) and consistent features of MTLE. Based on electro-clinical correlations we identified 4 groups:1) mesial group characterized by mesial seizure onset without evidence of early spread beyond the temporal lobe; 2) anterior mesio-lateral group (AML) with early anterior spread, involving the anterior lateral temporal cortex and insulo-fronto-opercular areas; 3) widespread mesio-lateral group (WML) with widespread spread, involving both anterior and posterior lateral temporal and peri-sylvian areas; 4) bi-temporal group (BT) with early contralateral temporal spread. Results of FDG-PET imaging in each group were compared to control subjects using statistical parametric mapping software (SPM99). MRI data and surgical outcome in each group were compared to metabolic findings. Hypo-metabolism was limited to the hippocampal gyrus, the temporal pole and the insula in the mesial group. Gradual involvement of the lateral temporal cortex, the insula and the peri-sylvian areas was observed in the AML and WML groups. The BT group differed from the others by mild bi-temporal involvement, bilateral insular hypo-metabolism and longer epilepsy duration. MRI

  1. PET imaging in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Semah, F. [Service Hospitalier Frederic Joliot, DSV-CEA, 91 Orsay (France)

    2006-07-01

    The research projects on epilepsy addressed two main issues: the pathophysiology of the inter-ictal hypo-metabolism in temporal lobe epilepsy and the role of the basal ganglia in the control of seizure. Our research projects focused primarily on temporal lobe epilepsy: The pathophysiology of inter-ictal hypo-metabolism and its correlation with the epileptogenic network was investigated in patients with mesial temporal lobe epilepsy. Inter-ictal hypo-metabolism is commonly found in mesio-temporal lobe epilepsy (MTLE) but its pathophysiology remains incompletely understood. We hypothesized that metabolic changes reflect the preferential networks involved in ictal discharges. We analyzed the topography of inter-ictal hypo-metabolism according to electro-clinical patterns in 50 patients with unilateral hippocampal sclerosis (HS) and consistent features of MTLE. Based on electro-clinical correlations we identified 4 groups:1) mesial group characterized by mesial seizure onset without evidence of early spread beyond the temporal lobe; 2) anterior mesio-lateral group (AML) with early anterior spread, involving the anterior lateral temporal cortex and insulo-fronto-opercular areas; 3) widespread mesio-lateral group (WML) with widespread spread, involving both anterior and posterior lateral temporal and peri-sylvian areas; 4) bi-temporal group (BT) with early contralateral temporal spread. Results of FDG-PET imaging in each group were compared to control subjects using statistical parametric mapping software (SPM99). MRI data and surgical outcome in each group were compared to metabolic findings. Hypo-metabolism was limited to the hippocampal gyrus, the temporal pole and the insula in the mesial group. Gradual involvement of the lateral temporal cortex, the insula and the peri-sylvian areas was observed in the AML and WML groups. The BT group differed from the others by mild bi-temporal involvement, bilateral insular hypo-metabolism and longer epilepsy duration. MRI

  2. Connectivity pattern differences bilaterally in the cerebellum posterior lobe in healthy subjects after normal sleep and sleep deprivation: a resting-state functional MRI study

    Directory of Open Access Journals (Sweden)

    Liu XM

    2015-05-01

    Full Text Available Xuming Liu,1 Zhihan Yan,2 Tingyu Wang,1 Xiaokai Yang,1 Feng Feng,3 Luping Fan,1 Jian Jiang4 1Department of Radiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, 2Department of Radiology, The 2nd Affiliated Hospital of Wenzhou Medical University, Wenzhou, 3Peking Union Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 4Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, People’s Republic of China Objective: The aim of this study was to use functional magnetic resonance imaging (fMRI technique to explore the resting-state functional connectivity (rsFC differences of the bilaterial cerebellum posterior lobe (CPL after normal sleep (NS and after sleep deprivation (SD. Methods: A total of 16 healthy subjects (eight males, eight females underwent an fMRI scan twice at random: once following NS and the other following 24 hours’ SD, with an interval of 1 month between the two scans. The fMRI scanning included resting state and acupuncture stimulation. The special activated regions located during the acupuncture stimulation were selected as regions of interest for rsFC analysis. Results: Bilateral CPLs were positively activated by acupuncture stimulation. In the NS group, the left CPL showed rsFC with the bilateral CPL, bilateral frontal lobe (BFL, left precuneus and right inferior parietal lobule, while the right CPL showed rsFC with the bilateral temporal lobe, right cerebellum anterior lobe, right CPL, left frontal lobe, left anterior cingulate, right posterior cingulate, and bilateral inferior parietal lobule. In the SD group, the left CPL showed rsFC with the left posterior cingulate gyrus bilateral CPL, left precuneus, left precentral gyrus, BFL, and the left parietal lobe, while the right CPL showed rsFC with bilateral cerebellum anterior lobe, bilateral CPL, left frontal lobe and left temporal lobe. Compared with the NS group, the

  3. Functional connectivity of parietal cortex during temporal selective attention.

    Science.gov (United States)

    Tyler, Sarah C; Dasgupta, Samhita; Agosta, Sara; Battelli, Lorella; Grossman, Emily D

    2015-04-01

    Perception of natural experiences requires allocation of attention towards features, objects, and events that are moving and changing over time. This allocation of attention is controlled by large-scale brain networks that, when damaged, cause widespread cognitive deficits. In particular, damage to ventral parietal cortex (right lateralized TPJ, STS, supramarginal and angular gyri) is associated with failures to selectively attend to and isolate features embedded within rapidly changing visual sequences (Battelli, Pascual-Leone, & Cavanagh, 2007; Husain, Shapiro, Martin, & Kennard, 1997). In this study, we used fMRI to investigate the neural activity and functional connectivity of intact parietal cortex while typical subjects judged the relative onsets and offsets of rapidly flickering tokens (a phase discrimination task in which right parietal patients are impaired). We found two regions in parietal cortex correlated with task performance: a bilateral posterior TPJ (pTPJ) and an anterior right-lateralized TPJ (R aTPJ). Both regions were deactivated when subjects engaged in the task but showed different patterns of functional connectivity. The bilateral pTPJ was strongly connected to nodes within the default mode network (DMN) and the R aTPJ was connected to the attention network. Accurate phase discriminations were associated with increased functional correlations between sensory cortex (hMT+) and the bilateral pTPJ, whereas accuracy on a control task was associated with yoked activity in the hMT+ and the R aTPJ. We conclude that temporal selective attention is particularly sensitive for revealing information pathways between sensory and core cognitive control networks that, when damaged, can lead to nonspatial attention impairments in right parietal stroke patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

    Science.gov (United States)

    Correani, Alessia; Humphreys, Glyn W

    2011-07-01

    The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

  5. Determination of hyperactive areas of Cortex Cerebri with using brain SPECT study

    International Nuclear Information System (INIS)

    Stepien, A.; Pawlus, J.; Wasilewska-Radwanska, M.

    2004-01-01

    The aim of this study was the assessment of the ability to apply of SPECT technique to determination of hyperactive areas of cortex cerebri. Analysis included 50 patients (mean aged 44 - 58). Brain SPECT scanning was performed after 1 hour after the intravenous injection of 740 MBq of ethylcisteinate dimmer labeled 99m Technetium (99mTc-ECD) with the use one-head gamma camera with a low-energy, ultra-high resolution collimator. Qualitative and quantitative analysis was performed using specialised software. In 20 cases normal biodistribution of the radiotracer was observed (hyperactive areas in cerebellum and occiput). In patients with psychiatric and neurological disturbances hyperactive areas were visualized in 25 cases in temporal lobes, in 4 cases in parietal lobes and in 1 patient in frontal area and basal ganglia. It is concluded that a number of factors limit the wide-scale use of SPECT, including the sophistication of imaging equipment (single-head cameras are inferior to the newer multihead units) and the experience of the physicians interpreting the scans and utilizing the data. In many diseases physicians do not know which areas of the patient's brain according disorders. Brain SPECT study can be a very useful tool to evaluation of hyperactive areas of cortex cerebri. This technique visualization of cortex cerebri completes standard analysis of disorders of brain activity

  6. Integration of Visual and Proprioceptive Limb Position Information in Human Posterior Parietal, Premotor, and Extrastriate Cortex.

    Science.gov (United States)

    Limanowski, Jakub; Blankenburg, Felix

    2016-03-02

    The brain constructs a flexible representation of the body from multisensory information. Previous work on monkeys suggests that the posterior parietal cortex (PPC) and ventral premotor cortex (PMv) represent the position of the upper limbs based on visual and proprioceptive information. Human experiments on the rubber hand illusion implicate similar regions, but since such experiments rely on additional visuo-tactile interactions, they cannot isolate visuo-proprioceptive integration. Here, we independently manipulated the position (palm or back facing) of passive human participants' unseen arm and of a photorealistic virtual 3D arm. Functional magnetic resonance imaging (fMRI) revealed that matching visual and proprioceptive information about arm position engaged the PPC, PMv, and the body-selective extrastriate body area (EBA); activity in the PMv moreover reflected interindividual differences in congruent arm ownership. Further, the PPC, PMv, and EBA increased their coupling with the primary visual cortex during congruent visuo-proprioceptive position information. These results suggest that human PPC, PMv, and EBA evaluate visual and proprioceptive position information and, under sufficient cross-modal congruence, integrate it into a multisensory representation of the upper limb in space. The position of our limbs in space constantly changes, yet the brain manages to represent limb position accurately by combining information from vision and proprioception. Electrophysiological recordings in monkeys have revealed neurons in the posterior parietal and premotor cortices that seem to implement and update such a multisensory limb representation, but this has been difficult to demonstrate in humans. Our fMRI experiment shows that human posterior parietal, premotor, and body-selective visual brain areas respond preferentially to a virtual arm seen in a position corresponding to one's unseen hidden arm, while increasing their communication with regions conveying visual

  7. ON THE ORIGIN OF FANAROFF-RILEY CLASSIFICATION OF RADIO GALAXIES: DECELERATION OF SUPERSONIC RADIO LOBES

    International Nuclear Information System (INIS)

    Kawakatu, Nozomu; Kino, Motoki; Nagai, Hiroshi

    2009-01-01

    We argue that the origin of 'FRI/FRII dichotomy' - the division between Fanaroff-Riley class I (FRI) with subsonic lobes and class II (FRII) radio sources with supersonic lobes is sharp in the radio-optical luminosity plane (Owen-White diagram) - can be explained by the deceleration of advancing radio lobes. The deceleration is caused by the growth of the effective cross-sectional area of radio lobes. We derive the condition in which an initially supersonic lobe turns into a subsonic lobe, combining the ram pressure equilibrium between the hot spots and the ambient medium with the relation between 'the hot spot radius' and 'the linear size of radio sources' obtained from the radio observations. We find that the dividing line between the supersonic lobes and subsonic ones is determined by the ratio of the jet power L j to the number density of the ambient matter at the core radius of the host galaxy n-bar a . It is also found that the maximal ratio of (L j ,n-bar a ) exists and its value resides in (L j ,n-bar a ) max ∼10 44-47 er s -1 cm 3 , taking into account considerable uncertainties. This suggests that the maximal value (L j ,n-bar a ) max separates between FRIs and FRIIs.

  8. A study using computerized tomography in the clinical practice of temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yamamoto, Kunimitsu

    1982-01-01

    The author has studied about analysis of clinical data and CT findings examined conventional method for 50 cases of temporal lobe epilepsy and how to assess the foci of temporal lobe by CT. According to the examination of conventional neuroradiologic technique and routine work of CT for temporal lobe epilepsy, an extreme space occuping lesions were detected and marked cerebral atrophy, low density area in temporal lobe were found out, but, most of them were not able to detect foci of the temporal lobe and yet, the study of CT number based on the print out data did not give any precise informations about epileptogenic lesions of temporal lobe epilepsy. The method of reversed axial section CT was designed to photograph inferior horn of lateral ventricles with the purpose to delineate the hippocampus and amygdata, and precise pictures from autopsy brain and clinical cases were obtained by that method about scanning angle of reversed axial section CT, various angles are made an experiment on scanning, such as reversed 15 0 , 20 0 , 25 0 , 30 0 , 35 0 . Among them, it is proved that the reversed angle of almost 25 0 is most suitable to delineate mesial temporal structure, so as to say, foci of the temporal lobe. (J.P.N.)

  9. Are personality traits of juvenile myoclonic epilepsy related to frontal lobe dysfunctions? A proton MRS study.

    Science.gov (United States)

    de Araújo Filho, Gerardo Maria; Lin, Katia; Lin, Jaime; Peruchi, Mirella M; Caboclo, Luís Otávio S F; Guaranha, Mirian S B; Guilhoto, Laura M F F; Carrete, Henrique; Yacubian, Elza Márcia T

    2009-05-01

    Personality traits characterized by emotional instability and immaturity, unsteadiness, lack of discipline, hedonism, frequent and rapid mood changes, and indifference toward one's disease have been associated with patients who have juvenile myoclonic epilepsy (JME). Literature data demonstrate worse seizure control and more psychosocial dysfunctions among patients with JME who have those traits. In this controlled study we performed a correlation analysis of psychiatric scores with magnetic resonance spectroscopy (MRS) values across JME patients, aiming to verify the existence of a possible relation between frontal lobe dysfunction and the prevalence of personality disorders (PDs) in JME. Sixteen JME patients with cluster B PDs, 41 JME patients without any psychiatric disorder, and 30 healthy controls were submitted to a psychiatric evaluation and to a quantitative multivoxel MRS of thalamus; insula; cingulate gyrus; striatum; and frontal, parietal, and occipital lobes. Groups were homogeneous according to age, gender, and manual dominance. Psychiatric evaluation was performed through the Scheduled Clinical Interview for DSM-IV, Axis I and II (SCID I and II, respectively). A significant reduction of N-acetyl-aspartate over creatinine (NAA/Cr) ratio was observed mainly in the left frontal lobe in the JME and PD group. In addition, a significant increase in the glutamate-glutamine over creatinine GLX/Cr ratio was also observed in this referred region in the same group. These data support the hypothesis that PDs in JME could represent neuronal dysfunction and possibly a more severe form of this epileptic syndrome.

  10. Transcranial magnetic stimulation of right inferior parietal cortex causally influences prefrontal activation for visual detection

    DEFF Research Database (Denmark)

    Leitao, Joana; Thielscher, Axel; Lee, Hweeling

    2017-01-01

    -parietal areas integrating the evidence into a decision variable that is compared to a decisional threshold. This concurrent transcranial magnetic stimulation (TMS)-fMRI study applied 10 Hz bursts of four TMS (or Sham) pulses to the intraparietal sulcus (IPS) to investigate the causal influence of IPS...... affect participants' performance accuracy, it affected how observers adjusted their response times after making an error. We therefore suggest that activation increases in superior frontal gyri for misses relative to correct responses may not be critical for signal detection performance, but rather...

  11. MRI lesion and epileptogenic focus in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Matsuda, Kazumi; Yagi, Kazuichi; Mihara, Tadahiro; Tottori, Takayasu; Watanabe, Yutaka; Seino, Masakazu

    1989-01-01

    The spatial relationship between a circumscribed lesion in the temporal lobe detected by MRI and an epileptogenic focus identified by ictal depth EEG along with a correlation of the MRI lesion with neuropathological findings were investigated in patients with medically intractable temporal lobe epilepsy but without any focal lesion on CT. Four parameters (an areal ratio of the temporal lobe against the hemisphere, area and calculated T1, T2 values of the hippocampus) were used to determine the abnormal MRI side. An agreement was reached in 67-72% of 18 patients between the abnormal values of the hippocampal area and of calculated T1, T2 and the side of the epileptogenic focus. In 14 of 17 patients, typical hippocampal sclerosis was demonstrated in resected tissue in accordance with the MRI lesions (atrophy and/or prolonged T2 of hippocampus). These results imply: 1)MRI abnormality thus defined may, if not all, indicate the side of the epileptogenic focus, and 2)also the presence of hippocampal sclerosis. It was emphasized that the MRI lesion would be a usable instrument to explore the causal relationship of hippocampal sclerosis to a generation of epileptogenic lesions as well as for presurgical evalution. (author)

  12. Emotional reactions in patients after frontal lobe stroke.

    Science.gov (United States)

    Stojanović, Zlatan; Stojanović, Sanja Vukadinović

    2015-09-01

    Emotional reactions have been documented after tumor lesions and the other damages of the brain. The aim of this paper was to examine the correlation between frontal lobe lesions and emotional reactions in patients with stroke. The research included 118 patients after stroke. Lesion localization was defined on computed axial tomography records, whereas the area and perimeter of lesion were measured by AutoCAD 2004 software. Examinations by means of the Hamilton Rating Scale for Anxiety and Depression (HRSA and HRSD) were carried out 11-40 days after stroke. Statistic data were processed by simple linear/nonlinear regression, Cox's and the generalized linear model. A higher frequency of emotional reactions, i.e. anxiety, was determined in women after stroke (p = 0.024). A negative correlation between the lesion size and the intensity of anxiety manifestations was determined (Spearman's r = -0.297; p = 0.001). Anxiety was more frequent in patients with frontal lobe lesions in the dominant hemisphere (interaction: frontal lesion * hand dominant hemisphere, p = 0.017). Also, HRSD score values showed the tendency for lesser decline in case of greater frontal lobe lesions in relation to lesions of other regions of prosencephalon (interaction: frontal lesion * lesion area, p = 0.001). The results of this study indicate the correlation between evolutionary younger structures of the central nervous system and emotional reactions of man. Therefore, it is necessary to undertake proper early psychopharmacotherapy in the vulnerable group of patients.

  13. Occipital lobe epilepsy with fear as leading ictal symptom.

    Science.gov (United States)

    Oehl, Bernhard; Schulze-Bonhage, Andreas; Lanz, Michael; Brandt, Armin; Altenmüller, Dirk-Matthias

    2012-03-01

    Ictal fear is a semiological feature which is commonly associated with mesial temporal lobe epilepsy. Here, we describe fear as a leading symptom in cryptogenic occipital lobe epilepsy. In a patient with negative MRI findings, intracranial EEG recordings documented a strict correlation between habitual ictal anxiety attacks and both spontaneous and stimulation-induced epileptic activity in a right occipital epileptogenic area with subsequent spreading to the symptomatogenic zone in the amygdala. Circumscribed occipital topectomy led to seizure freedom. Episodes of non-epileptic fear ceased shortly afterwards. This report provides insight into pathways of propagation of epileptic activity, illustrates different etiologies of pathologic fear and underlines the importance of ictal EEG recordings. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Women with a history of childhood maltreatment exhibit more activation in association areas following non-traumatic olfactory stimuli: a fMRI study.

    Directory of Open Access Journals (Sweden)

    Ilona Croy

    2010-02-01

    Full Text Available The aim of this study was investigating how women with a history of childhood maltreatment (CM process non-threatening and non-trauma related olfactory stimuli. The focus on olfactory perception is based on the overlap of brain areas often proposed to be affected in CM patients and the projection areas of the olfactory system, including the amygdala, orbitofrontal cortex, insula and hippocampus.Twelve women with CM and 10 controls participated in the study. All participants were, or have been, patients in a psychosomatic clinic. Participants underwent a fMRI investigation during olfactory stimulation with a neutral (coffee and a pleasant (peach odor. Furthermore, odor threshold and odor identification (Sniffin' Sticks were tested.Both groups showed normal activation in the olfactory projection areas. However, in the CM-group we found additionally enhanced activation in multiple, mainly neocortical, areas that are part of those involved in associative networks. These include the precentral frontal lobe, inferior and middle frontal structures, posterior parietal lobe, occipital lobe, and the posterior cingulate cortex.The results indicate that in this group of patients, CM was associated with an altered processing of olfactory stimuli, but not development of a functional olfactory deficit. This complements other studies on CM insofar as we found the observed pattern of enhanced activation in associative and emotional regions even following non-traumatic olfactory cues.

  15. Alterations of the occipital lobe in schizophrenia.

    Science.gov (United States)

    Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

    2015-07-01

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

  16. Pressure balance between lobe and plasma sheet

    International Nuclear Information System (INIS)

    Baumjohann, W.; Paschmann, G.; Luehr, H.

    1990-01-01

    Using eight months of AMPTE/IRM plasma and magnetic field data, the authors have done a statistical survey on the balance of total (thermal and magnetic) pressure in the Earth's plasma sheet and tail lobe. About 300,000 measurements obtained in the plasma sheet and the lobe were compared for different levels of magnetic activity as well as different distances from the Earth. The data show that lobe and plasma sheet pressure balance very well. Even in the worst case they do not deviate by more than half of the variance in the data itself. Approximately constant total pressure was also seen during a quiet time pass when IRM traversed nearly the whole magnetotail in the vertical direction, from the southern hemisphere lobe through the neutral sheet and into the northern plasma sheet boundary layer

  17. Microsurgical techniques in temporal lobe epilepsy.

    Science.gov (United States)

    Alonso Vanegas, Mario A; Lew, Sean M; Morino, Michiharu; Sarmento, Stenio A

    2017-04-01

    Temporal lobe resection is the most prevalent epilepsy surgery procedure. However, there is no consensus on the best surgical approach to treat temporal lobe epilepsy. Complication rates are low and efficacy is very high regarding seizures after such procedures. However, there is still ample controversy regarding the best surgical approach to warrant maximum seizure control with minimal functional deficits. We describe the most frequently used microsurgical techniques for removal of both the lateral and mesial temporal lobe structures in the treatment of medically intractable temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (corticoamygdalohippocampectomy and selective amygdalohippocampectomy). The choice of surgical technique appears to remain a surgeon's preference for the near future. Meticulous surgical technique and thorough three-dimensional microsurgical knowledge are essentials for obtaining the best results. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  18. Deployment Instabilities of Lobed-Pumpkin Balloon

    Science.gov (United States)

    Nakashino, Kyoichi

    A lobed-pumpkin balloon, currently being developed in ISAS/JAXA as well as in NASA, is a promising vehicle for long duration scientific observations in the stratosphere. Recent ground and flight experiments, however, have revealed that the balloon has deployment instabilities under certain conditions. In order to overcome the instability problems, a next generation SPB called 'tawara' type balloon has been proposed, in which an additional cylindrical part is appended to the standard lobed-pumpkin balloon. The present study investigates the deployment stability of tawara type SPB in comparison to that of standard lobed-pumpkin SPB through eigenvalue analysis on the basis of finite element methods. Our numerical results show that tawara type SPB enjoys excellent deployment performance over the standard lobed-pumpkin SPBs.

  19. Alterations of the occipital lobe in schizophrenia

    Science.gov (United States)

    Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

    2015-01-01

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

  20. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H215O PET

    International Nuclear Information System (INIS)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2002-01-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H 2 15 O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period

  1. Differences in the neural correlates of frontal lobe tests.

    Science.gov (United States)

    Matsuoka, Teruyuki; Kato, Yuka; Imai, Ayu; Fujimoto, Hiroshi; Shibata, Keisuke; Nakamura, Kaeko; Yamada, Kei; Narumoto, Jin

    2018-01-01

    The Executive Interview (EXIT25), the executive clock-drawing task (CLOX1), and the Frontal Assessment Battery (FAB) are used to assess executive function at the bedside. These tests assess distinct psychometric properties. The aim of this study was to examine differences in the neural correlates of the EXIT25, CLOX1, and FAB based on magnetic resonance imaging. Fifty-eight subjects (30 with Alzheimer's disease, 10 with mild cognitive impairment, and 18 healthy controls) participated in this study. Multiple regression analyses were performed to examine the brain regions correlated with the EXIT25, CLOX1, and FAB scores. Age, gender, and years of education were included as covariates. Statistical thresholds were set to uncorrected P-values of 0.001 at the voxel level and 0.05 at the cluster level. The EXIT25 score correlated inversely with the regional grey matter volume in the left lateral frontal lobe (Brodmann areas 6, 9, 44, and 45). The CLOX1 score correlated positively with the regional grey matter volume in the right orbitofrontal cortex (Brodmann area 11) and the left supramarginal gyrus (Brodmann area 40). The FAB score correlated positively with the regional grey matter volume in the right precentral gyrus (Brodmann area 6). The left lateral frontal lobe (Brodmann area 9) and the right lateral frontal lobe (Brodmann area 46) were identified as common brain regions that showed association with EXIT25, CLOX1, and FAB based only a voxel-level threshold. The results of this study suggest that the EXIT25, CLOX1, and FAB may be associated with the distinct neural correlates of the frontal cortex. © 2018 Japanese Psychogeriatric Society.

  2. Fronto-parietal contributions to phonological processes in successful artificial grammar learning

    Directory of Open Access Journals (Sweden)

    Dariya Goranskaya

    2016-11-01

    Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

  3. Temporary interference over the posterior parietal cortices disrupts thermoregulatory control in humans.

    Directory of Open Access Journals (Sweden)

    Alberto Gallace

    Full Text Available The suggestion has recently been made that certain higher-order cortical areas involved in supporting multisensory representations of the body, and of the space around it, might also play a role in controlling thermoregulatory functions. Here we demonstrate that temporary interference with the function of one of these areas, the posterior parietal cortex, by repetitive transcranial magnetic stimulation, results in a decrease in limb temperature. By contrast, interference with the activity of a sensory-specific area (the primary somatosensory cortex had no effect on temperature. The results of this experiment suggest that associative multisensory brain areas might exert a top-down modulation over basic physiological control. Such a function might be part of a larger neural circuit responsible for maintaining the integrity of the body at both a homeostatic and a psychological level.

  4. Parietal seeding of unsuspected gallbladder carcinoma after laparoscopic cholecystectomy.

    Science.gov (United States)

    Marmorale, C; Scibé, R; Siquini, W; Massa, M; Brunelli, A; Landi, E

    1998-01-01

    Laparoscopic cholecystectomy (VALC) represents the treatment of choice for the symptomatic gallstones. However the occurrence of an adenocarcinoma of the gallbladder results a controindication for this surgical technique. We present a case of a 52 years old woman who underwent a VALC; histology revealed a gallbladder adenocarcinoma. For this reason the patient underwent a second operation that is right hepatic trisegmentectomy. Six months later the patient presented with a parietal recurrence at the extraction site of the gallbladder. We discuss the possible mechanism responsible for carcinomatous dissemination during laparoscopic surgery and we raccommend the use of some procedures in order to limit the risk and eventually to treat a neoplastic parietal seeding. These complications suggest the problem about the utility and the future played by video assisted laparoscopic surgery in the diagnosis and treatment of intraabdominal malignancies.

  5. Choline acetyltransferase-containing neurons in the human parietal neocortex

    Directory of Open Access Journals (Sweden)

    V Benagiano

    2009-06-01

    Full Text Available A number of immunocytochemical studies have indicated the presence of cholinergic neurons in the cerebral cortex of various species of mammals. Whether such cholinergic neurons in the human cerebral cortex are exclusively of subcortical origin is still debated. In this immunocytochemical study, the existence of cortical cholinergic neurons was investigated on surgical samples of human parietal association neocortex using a highly specific monoclonal antibody against choline acetyltransferase (ChAT, the acetylcholine biosynthesising enzyme. ChAT immunoreactivity was detected in a subpopulation of neurons located in layers II and III. These were small or medium-sized pyramidal neurons which showed cytoplasmic immunoreactivity in the perikarya and processes, often in close association to blood microvessels. This study, providing demonstration of ChAT neurons in the human parietal neocortex, strongly supports the existence of intrinsic cholinergic innervation of the human neocortex. It is likely that these neurons contribute to the cholinergic innervation of the intracortical microvessels.

  6. Gelastic seizures and the anteromesial frontal lobe: a case report and review of intracranial EEG recording and electrocortical stimulation case studies.

    Science.gov (United States)

    Unnwongse, Kanjana; Wehner, Tim; Bingaman, William; Foldvary-Schaefer, Nancy

    2010-10-01

    Symptomatogenic areas for ictal laughter have been described in the frontal and temporal lobes. Within the frontal lobe, gelastic seizures have been recorded from the cingulate gyrus. Electrocortical stimulation of the cingulate gyrus as well as the superior frontal gyrus induced laughter. We describe a patient whose gelastic seizures were associated with electrographic ictal activity in the mesial aspect of the right anterior frontal gyrus. The symptomatogenic area for ictal laughter in the frontal lobe may reside in the superior frontal gyrus.

  7. Neuronal oscillations form parietal/frontal networks during contour integration.

    Science.gov (United States)

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

  8. Parietal cells?new perspectives in glomerular disease

    OpenAIRE

    Miesen, Laura; Steenbergen, Eric; Smeets, Bart

    2017-01-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman?s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertain...

  9. Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

    International Nuclear Information System (INIS)

    Rozeik, C.; Kotterer, O.; Deininger, H.K.

    1994-01-01

    We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

  10. Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

    Energy Technology Data Exchange (ETDEWEB)

    Rozeik, C. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Kotterer, O. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Deininger, H.K. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany)

    1994-10-01

    We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

  11. Glomerular parietal epithelial cells in kidney physiology, pathology, and repair

    OpenAIRE

    Shankland, Stuart J.; Anders, Hans-Joachim; Romagnani, Paola

    2013-01-01

    Purpose of review We have summarized recently published glomerular parietal epithelial cell (PEC) research, focusing on their roles in glomerular development and physiology, and in certain glomerular diseases. The rationale is that PECs have been largely ignored until the recent availability of cell lineage tracing studies, human and murine PEC culture systems, and potential therapeutic interventions of PECs. Recent findings Several new paradigms involving PECs have emerged demonstrating thei...

  12. The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

    OpenAIRE

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J.

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glo...

  13. Comparison of visual receptive fields in the dorsolateral prefrontal cortex and ventral intraparietal area in macaques.

    Science.gov (United States)

    Viswanathan, Pooja; Nieder, Andreas

    2017-12-01

    The concept of receptive field (RF) describes the responsiveness of neurons to sensory space. Neurons in the primate association cortices have long been known to be spatially selective but a detailed characterisation and direct comparison of RFs between frontal and parietal association cortices are missing. We sampled the RFs of a large number of neurons from two interconnected areas of the frontal and parietal lobes, the dorsolateral prefrontal cortex (dlPFC) and ventral intraparietal area (VIP), of rhesus monkeys by systematically presenting a moving bar during passive fixation. We found that more than half of neurons in both areas showed spatial selectivity. Single neurons in both areas could be assigned to five classes according to the spatial response patterns: few non-uniform RFs with multiple discrete response maxima could be dissociated from the vast majority of uniform RFs showing a single maximum; the latter were further classified into full-field and confined foveal, contralateral and ipsilateral RFs. Neurons in dlPFC showed a preference for the contralateral visual space and collectively encoded the contralateral visual hemi-field. In contrast, VIP neurons preferred central locations, predominantly covering the foveal visual space. Putative pyramidal cells with broad-spiking waveforms in PFC had smaller RFs than putative interneurons showing narrow-spiking waveforms, but distributed similarly across the visual field. In VIP, however, both putative pyramidal cells and interneurons had similar RFs at similar eccentricities. We provide a first, thorough characterisation of visual RFs in two reciprocally connected areas of a fronto-parietal cortical network. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  14. True and False Memories, Parietal Cortex, and Confidence Judgments

    Science.gov (United States)

    Urgolites, Zhisen J.; Smith, Christine N.; Squire, Larry R.

    2015-01-01

    Recent studies have asked whether activity in the medial temporal lobe (MTL) and the neocortex can distinguish true memory from false memory. A frequent complication has been that the confidence associated with correct memory judgments (true memory) is typically higher than the confidence associated with incorrect memory judgments (false memory).…

  15. Flash visual evoked potentials are not specific enough to identify parieto-occipital lobe involvement in term neonates after significant hypoglycaemia.

    Science.gov (United States)

    Hu, Liyuan; Gu, Qiufang; Zhu, Zhen; Yang, Chenhao; Chen, Chao; Cao, Yun; Zhou, Wenhao

    2014-08-01

    Hypoglycaemia is a significant problem in high-risk neonates and predominant parieto-occipital lobe involvement has been observed after severe hypoglycaemic insult. We explored the use of flash visual evoked potentials (FVEP) in detecting parieto-occipital lobe involvement after significant hypoglycaemia. Full-term neonates (n = 15) who underwent FVEP from January 2008 to May 2013 were compared with infants (n = 11) without hypoglycaemia or parietal-occipital lobe injury. Significant hypoglycaemia was defined as being symptomatic or needing steroids, glucagon or a glucose infusion rate of ≥12 mg/kg/min. The hypoglycaemia group exhibited delayed latency of the first positive waveform on FVEP. The initial detected time for hypoglycaemia was later in the eight subjects with seizures (median 51-h-old) than those without (median 22-h-old) (P = 0.003). Magnetic resonance imaging showed that 80% of the hypoglycaemia group exhibited occipital-lobe injuries, and they were more likely to exhibit abnormal FVEP morphology (P = 0.007) than the controls. FVEP exhibited 100% sensitivity, but only 25% specificity, for detecting injuries to the parieto-occipital lobes. Flash visual evoked potential (FVEP) was sensitive, but not sufficiently specific, in identifying parieto-occipital lobe injuries among term neonates exposed to significant hypoglycaemia. Larger studies exploring the potential role of FVEP in neonatal hypoglycaemia are required. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  16. Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

    Science.gov (United States)

    Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

    2011-01-01

    The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

  17. Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

    Science.gov (United States)

    Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

    2016-09-28

    Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

  18. MRI findings of temporal lobe ganglioglioma

    International Nuclear Information System (INIS)

    Lee, Myung Jun; Lee, Ho Kyu; Lee, Jung Kyo; Choi, Choong Gon; Suh, Dae Chul

    1999-01-01

    Ganglioglioma is a rare primary brain tumor usually found in the temporal lobe. The purpose of this study is to describe the characteristic MR findings of temporal lobe ganglioglioma. Over a seven-year period, ten patients with cerebral ganglioglioma were evaluated at our institution. Seven cases of temporal lobe ganglioma were found ; six of these involved men, and one, a woman ; their mean age was 29.6 years. In three patients, Gd-DTPA-enhanced T1-weighted images were also obtained. We retrospectively analysed the MRI findings with respect to location, size, cortical involvement, margin, cystic change, degree of enhancement, MR signal intensity, calcification and peritumoral change. In five cases, tumors were located within the temporal lobe. In one, a tumor extended from the temporal lobe to the thalamus, and in one from the temporal lobe to the thalamus and cerebral peduncle. All temporal gangliogliomas measured 1.6-3.8cm in their greatest diameter (mean diameter, 2.7cm). In all cases, the cortices were involved with the maintenance of gyriform. The tumor margin was ill defined in five cases and well defined in two. Tumors showed multiple small cystic changes in four cases, a large cyst in two, and a solid nodule in one. In three cases in which contrast media was administered, no lesions were enhanced. On T1-weighted images, iso-signal intensities were seen in five cases and high signal intensities in two. On T2-weighted images, the corresponding figures were five and two. On MRI, tumor calcification and calvarial erosion were each detected in two cases. In patients with temporal lobe epilepsy in whom cortical solid or cystic and poorly enhanced lesions were seen on brain MRI, and in whom associated findings such as calcification and or adjacent bony erosion were noted, ganglioglioma must be considered

  19. MRI parcellation of ex vivo medial temporal lobe.

    Science.gov (United States)

    Augustinack, Jean C; Magnain, Caroline; Reuter, Martin; van der Kouwe, André J W; Boas, David; Fischl, Bruce

    2014-06-01

    Recent advancements in radio frequency coils, field strength and sophisticated pulse sequences have propelled modern brain mapping and have made validation to biological standards - histology and pathology - possible. The medial temporal lobe has long been established as a pivotal brain region for connectivity, function and unique structure in the human brain, and reveals disconnection in mild Alzheimer's disease. Specific brain mapping of mesocortical areas affected with neurofibrillary tangle pathology early in disease progression provides not only an accurate description for location of these areas but also supplies spherical coordinates that allow comparison between other ex vivo cases and larger in vivo datasets. We have identified several cytoarchitectonic features in the medial temporal lobe with high resolution ex vivo MRI, including gray matter structures such as the entorhinal layer II 'islands', perirhinal layer II-III columns, presubicular 'clouds', granule cell layer of the dentate gyrus as well as lamina of the hippocampus. Localization of Brodmann areas 28 and 35 (entorhinal and perirhinal, respectively) demonstrates MRI based area boundaries validated with multiple methods and histological stains. Based on our findings, both myelin and Nissl staining relate to contrast in ex vivo MRI. Precise brain mapping serves to create modern atlases for cortical areas, allowing accurate localization with important applications to detecting early disease processes. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Observational learning of new movement sequences is reflected in fronto-parietal coherence.

    Directory of Open Access Journals (Sweden)

    Jurjen van der Helden

    Full Text Available Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha and motor (mu rhythms operating in the 10 Hz frequency range for translating "seeing" into "doing". Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for

  1. The occipital lobe convexity sulci and gyri.

    Science.gov (United States)

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

    2012-05-01

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

  2. Matrix metalloproteinase-9 expression is enhanced in renal parietal epithelial cells of zucker diabetic Fatty rats and is induced by albumin in in vitro primary parietal cell culture.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhang

    Full Text Available As a subfamily of matrix metalloproteinases (MMPs, gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive

  3. Deficits in visual search for conjunctions of motion and form after parietal damage but with spared hMT+/V5.

    Science.gov (United States)

    Dent, Kevin; Lestou, Vaia; Humphreys, Glyn W

    2010-02-01

    It has been argued that area hMT+/V5 in humans acts as a motion filter, enabling targets defined by a conjunction of motion and form to be efficiently selected. We present data indicating that (a) damage to parietal cortex leads to a selective problem in processing motion-form conjunctions, and (b) that the presence of a structurally and functional intact hMT+/V5 is not sufficient for efficient search for motion-form conjunctions. We suggest that, in addition to motion-processing areas (e.g., hMT+/V5), the posterior parietal cortex is necessary for efficient search with motion-form conjunctions, so that damage to either brain region may bring about deficits in search. We discuss the results in terms of the involvement of the posterior parietal cortex in the top-down guidance of search or in the binding of motion and form information.

  4. Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

    Science.gov (United States)

    Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

    2015-08-19

    The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

  5. Infectious Causes of Right Middle Lobe Syndrome.

    Science.gov (United States)

    Rashid, Aatif; Nanjappa, Sowmya; Greene, John N

    2017-01-01

    Right middle lobe (RML) syndrome is defined as recurrent or chronic obstruction or infection of the middle lobe of the right lung. Nonobstructive causes of middle lobe syndrome include inflammatory processes and defects in the bronchial anatomy and collateral ventilation. We report on 2 case patients with RML syndrome, one due to infection with Mycobacterium avium complex followed by M asiaticum infection and the other due to allergic bronchopulmonary aspergillosis. A history of atopy, asthma, or chronic obstructive pulmonary disease has been reported in up to one-half of those with RML. The diagnosis can be made by plain radiography, computed tomography, and bronchoscopy. Medical treatment consists of bronchodilators, mucolytics, and antimicrobials. Patients whose disease is unresponsive to treatment and those with obstructive RML syndrome can be offered surgical treatment.

  6. Lung lobe collapse: pathophysiology and radiologic significance

    International Nuclear Information System (INIS)

    Lord, P.F.; Gomez, J.A.

    1985-01-01

    The radiographic changes caused by collapse of lung lobes in pulmonary disease, pneumothorax, and pleural effusion depend on the lobar recoiling force and local pleural pressure. Differences in the tendency of normal lung lobes or regions to collapse depend on the relative surface-to-volume ratio, determined by shape and size of the region or lobe. This ratio affects the physiologic parameters of pulmonary interdependence, compliance, and collateral air flow. Pulmonary surfactant increases compliance, particularly at low volumes, maintains alveolar stability, and assists in maintaining capillary patency and preventing pulmonary edema. Its loss due to lung injury increases collapsing forces. In the presence of pneumothorax or pleural effusion, diseases that cause lobar collapse produce localized air or fluid entrapment that is a diagnostic sign of the presence of the underlying pulmonary disease

  7. 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

    2015-01-01

    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.

  8. Study on memories of temporal lobes and the principles of lateralization using near infrared spectroscopy

    Science.gov (United States)

    Kamakura, Katsutoshi

    2007-01-01

    In this study we measured the variation of brain blood quantity (Oxy-Hb, Deoxy-Hb and Total-Hb) in the temporal lobes using near infrared spectroscopy (NIRS) when the tasks of the memories were presented to the subjects. The memories are classified into the short-term memory (STM) and the long-term memory (LTM) including the episodic and semantic memories. The subjects joined in this study are 11 persons who are university students including graduate students. We used the language task of letter-number sequencing, also reverse sequencing to measure STM and the task of the episodic memory to measure LTM. As a result of analysis, concerning the episodic memory, the variation of Oxy-Hb in the left temporal lobe was larger than that of Oxy-Hb in the right temporal lobe. The result might suggest that the episodic memory has a relationship with cerebral dominance concerning language area in the left temporal lobe. It seems that the episodic memory meditated with the function of language used in this study is much stored in the left temporal lobe than in the right temporal lobe. This result coincides with the principles of lateralization. The variation of Oxy-Hb in the language task of letter-number sequencing was smaller than that of Oxy-Hb in the language task of the episodic memory.

  9. Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

    Directory of Open Access Journals (Sweden)

    Paulina M Kowalewska

    Full Text Available BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138 was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2, anti-KC (CXCL1 or anti-MCP-1 (CCL2. RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18, ICAM-1 (CD54 and VCAM-1 (CD106 did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte

  10. Distinct antigenic characteristics of murine parietal yolk sac laminin

    DEFF Research Database (Denmark)

    Wewer, U M; Tichy, D; Damjanov, A

    1987-01-01

    Two monoclonal antibodies (LAM-A and LAM-B) specific for laminin from normal and neoplastic parietal yolk sac (PYS) cells were produced in rats immunized with a mouse yolk sac carcinoma cell line. Both antibodies immunoprecipitated the 400,000- and 200,000-Da chains of laminin and reacted...... with purified PYS laminin in ELISA. LAM-A reacted with mouse and rat PYS laminin, whereas LAM-B reacted only with mouse PYS laminin. Formaldehyde- and methanol-fixed adult and fetal somatic tissues were immunohistochemically unreactive with either of the two antibodies. In acetone-fixed tissue sections, both...

  11. Differential contributions of the superior and inferior parietal cortex to feedback versus feedforward control of tools.

    Science.gov (United States)

    Macuga, Kristen L; Frey, Scott H

    2014-05-15

    Damage to the superior and/or inferior parietal lobules (SPL, IPL) (Sirigu et al., 1996) or cerebellum (Grealy and Lee, 2011) can selectively disrupt motor imagery, motivating the hypothesis that these regions participate in predictive (i.e., feedforward) control. If so, then the SPL, IPL, and cerebellum should show greater activity as the demands on feedforward control increase from visually-guided execution (closed-loop) to execution without visual feedback (open-loop) to motor imagery. Using fMRI and a Fitts' reciprocal aiming task with tools directed at targets in far space, we found that the SPL and cerebellum exhibited greater activity during closed-loop control. Conversely, open-loop and imagery conditions were associated with increased activity within the IPL and prefrontal areas. These results are consistent with a superior-to-inferior gradient in the representation of feedback-to-feedforward control within the posterior parietal cortex. Additionally, the anterior SPL displayed greater activity when aiming movements were performed with a stick vs. laser pointer. This may suggest that it is involved in the remapping of far into near (reachable) space (Maravita and Iriki, 2004), or in distalization of the end-effector from hand to stick (Arbib et al., 2009). Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Mechanisms within the Parietal Cortex Correlate with the Benefits of Random Practice in Motor Adaptation

    Directory of Open Access Journals (Sweden)

    Benjamin Thürer

    2017-08-01

    Full Text Available The motor learning literature shows an increased retest or transfer performance after practicing under unstable (random conditions. This random practice effect (also known as contextual interference effect is frequently investigated on the behavioral level and discussed in the context of mechanisms of the dorsolateral prefrontal cortex and increased cognitive efforts during movement planning. However, there is a lack of studies examining the random practice effect in motor adaptation tasks and, in general, the underlying neural processes of the random practice effect are not fully understood. We tested 24 right-handed human subjects performing a reaching task using a robotic manipulandum. Subjects learned to adapt either to a blocked or a random schedule of different force field perturbations while subjects’ electroencephalography (EEG was recorded. The behavioral results showed a distinct random practice effect in terms of a more stabilized retest performance of the random compared to the blocked practicing group. Further analyses showed that this effect correlates with changes in the alpha band power in electrodes over parietal areas. We conclude that the random practice effect in this study is facilitated by mechanisms within the parietal cortex during movement execution which might reflect online feedback mechanisms.

  13. Inverted Lobes Have Satisfactory Functions Compared With Noninverted Lobes in Lung Transplantation.

    Science.gov (United States)

    Kayawake, Hidenao; Chen-Yoshikawa, Toyofumi F; Motoyama, Hideki; Hamaji, Masatsugu; Hijiya, Kyoko; Aoyama, Akihiro; Goda, Yasufumi; Oda, Hiromi; Ueda, Satoshi; Date, Hiroshi

    2018-04-01

    To overcome the problem of small-for-size grafts in standard living-donor lobar lung transplantation (LDLLT), we developed inverted LDLLT, in which a right lower lobe from 1 donor is implanted as a right graft and another right lower lobe from another donor is implanted as a left graft. We retrospectively analyzed the functions of inverted grafts vs noninverted grafts. Between 2008 and 2015, 64 LDLLTs were performed. Included were 35 LDLLTs whose recipients were adults and monitored for more than 6 months without developing chronic lung allograft dysfunction. Among them, 65 implanted lobes were eligible for this analysis. There were 31 right lower lobes implanted as right grafts (right-to-right group), 7 right lower lobes as inverted left grafts (right-to-left group), and 27 left lower lobes as left grafts (left-to-left group). We evaluated the graft forced vital capacity (G-FVC) and graft volume of the 65 lobes before and 6 months after LDLLT and compared them among the three groups. Preoperatively, G-FVC in the right-to-left group (1,050 mL) was comparable to that in the right-to-right group (1,177 mL) and better than that in the left-to-left group (791 mL, p satisfactory compared with those of noninverted grafts. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Temporal lobe sclerosis associated with hippocampal sclerosis in temporal lobe epilepsy: neuropathological features.

    Science.gov (United States)

    Thom, Maria; Eriksson, Sofia; Martinian, Lillian; Caboclo, Luis O; McEvoy, Andrew W; Duncan, John S; Sisodiya, Sanjay M

    2009-08-01

    Widespread changes involving neocortical and mesial temporal lobe structures can be present in patients with temporal lobe epilepsy and hippocampal sclerosis. The incidence, pathology, and clinical significance of neocortical temporal lobe sclerosis (TLS) are not well characterized. We identified TLS in 30 of 272 surgically treated cases of hippocampal sclerosis. Temporal lobe sclerosis was defined by variable reduction of neurons from cortical layers II/III and laminar gliosis; it was typically accompanied by additional architectural abnormalities of layer II, that is, abnormal neuronal orientation and aggregation. Quantitative analysis including tessellation methods for the distribution of layer II neurons supported these observations. In 40% of cases, there was a gradient of TLS with more severe involvement toward the temporal pole, possibly signifying involvement of hippocampal projection pathways. There was a history of a febrile seizure as an initial precipitating injury in 73% of patients with TLS compared with 36% without TLS; no other clinical differences between TLS and non-TLS cases were identified. Temporal lobe sclerosis was not evident preoperatively by neuroimaging. No obvious effect of TLS on seizure outcome was noted after temporal lobe resection; 73% became seizure-free at 2-year follow-up. In conclusion, approximately 11% of surgically treated hippocampal sclerosis is accompanied by TLS. Temporal lobe sclerosis is likely an acquired process with accompanying reorganizational dysplasia and an extension of mesial temporal sclerosis rather than a separate pathological entity.

  15. Thalamo-Cortical Disruption Contributes to Short-Term Memory Deficits in Patients with Medial Temporal Lobe Damage.

    Science.gov (United States)

    Voets, Natalie L; Menke, Ricarda A L; Jbabdi, Saad; Husain, Masud; Stacey, Richard; Carpenter, Katherine; Adcock, Jane E

    2015-11-01

    Short-term (STM) and long-term memory (LTM) have largely been considered as separate brain systems reflecting fronto-parietal and medial temporal lobe (MTL) functions, respectively. This functional dichotomy has been called into question by evidence of deficits on aspects of working memory in patients with MTL damage, suggesting a potentially direct hippocampal contribution to STM. As the hippocampus has direct anatomical connections with the thalamus, we tested the hypothesis that damage to thalamic nuclei regulating cortico-cortical interactions may contribute to STM deficits in patients with hippocampal dysfunction. We used diffusion-weighted magnetic resonance imaging-based tractography to identify anatomical subdivisions in patients with MTL epilepsy. From these, we measured resting-state functional connectivity with detailed cortical divisions of the frontal, temporal, and parietal lobes. Whereas thalamo-temporal functional connectivity reflected LTM performance, thalamo-prefrontal functional connectivity specifically predicted STM performance. Notably, patients with hippocampal volume loss showed thalamic volume loss, most prominent in the pulvinar region, not detected in patients with normal hippocampal volumes. Aberrant thalamo-cortical connectivity in the epileptic hemisphere was mirrored in a loss of behavioral association with STM performance specifically in patients with hippocampal atrophy. These findings identify thalamo-cortical disruption as a potential mechanism contributing to STM deficits in the context of MTL damage. © The Author 2015. Published by Oxford University Press.

  16. Multimodal imaging of language reorganization in patients with left temporal lobe epilepsy.

    Science.gov (United States)

    Chang, Yu-Hsuan A; Kemmotsu, Nobuko; Leyden, Kelly M; Kucukboyaci, N Erkut; Iragui, Vicente J; Tecoma, Evelyn S; Kansal, Leena; Norman, Marc A; Compton, Rachelle; Ehrlich, Tobin J; Uttarwar, Vedang S; Reyes, Anny; Paul, Brianna M; McDonald, Carrie R

    2017-07-01

    This study explored the relationships among multimodal imaging, clinical features, and language impairment in patients with left temporal lobe epilepsy (LTLE). Fourteen patients with LTLE and 26 controls underwent structural MRI, functional MRI, diffusion tensor imaging, and neuropsychological language tasks. Laterality indices were calculated for each imaging modality and a principal component (PC) was derived from language measures. Correlations were performed among imaging measures, as well as to the language PC. In controls, better language performance was associated with stronger left-lateralized temporo-parietal and temporo-occipital activations. In LTLE, better language performance was associated with stronger right-lateralized inferior frontal, temporo-parietal, and temporo-occipital activations. These right-lateralized activations in LTLE were associated with right-lateralized arcuate fasciculus fractional anisotropy. These data suggest that interhemispheric language reorganization in LTLE is associated with alterations to perisylvian white matter. These concurrent structural and functional shifts from left to right may help to mitigate language impairment in LTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study.

    Science.gov (United States)

    Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos

    2014-10-01

    To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Collaborative activity between parietal and dorso-lateral prefrontal cortex in dynamic spatial working memory revealed by fMRI.

    Science.gov (United States)

    Diwadkar, V A; Carpenter, P A; Just, M A

    2000-07-01

    Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory. Copyright 2000 Academic Press.

  19. Emotional reactions in patients after frontal lobe stroke

    Directory of Open Access Journals (Sweden)

    Stojanović Zlatan

    2015-01-01

    Full Text Available Background/Aim. Emotional reactions have been documented after tumor lesions and the other damages of the brain. The aim of this paper was to examine the correlation between frontal lobe lesions and emotional reactions in patients with stroke. Methods. The research included 118 patients after stroke. Lesion localization was defined on computed axial tomography records, whereas the area and perimeter of lesion were measured by AutoCAD 2004 software. Examinations by means of the Hamilton Rating Scale for Anxiety and Depression (HRSA and HRSD were carried out 11-40 days after stroke. Statistic data were processed by simple linear/nonlinear regression, Cox's and the generalized linear model. Results. A higher frequency of emotional reactions, i.e. anxiety, was determined in women after stroke (p = 0.024. A negative correlation between the lesion size and the intensity of anxiety manifestations was determined (Spearman’s r = -0.297; p = 0.001. Anxiety was more frequent in patients with frontal lobe lesions in the dominant hemisphere (interaction: frontal lesion * hand dominant hemisphere, p = 0.017. Also, HRSD score values showed the tendency for lesser decline in case of greater frontal lobe lesions in relation to lesions of other regions of prosencephalon (interaction: frontal lesion * lesion area, p = 0.001. Conclusion. The results of this study indicate the correlation between evolutionary younger structures of the central nervous system and emotional reactions of man. Therefore, it is necessary to undertake proper early psychopharmacotherapy in the vulnerable group of patients.

  20. Preservation of episodic memory in semantic dementia: The importance of regions beyond the medial temporal lobes.

    Science.gov (United States)

    Irish, Muireann; Bunk, Steffie; Tu, Sicong; Kamminga, Jody; Hodges, John R; Hornberger, Michael; Piguet, Olivier

    2016-01-29

    Episodic memory impairment represents one of the hallmark clinical features of patients with Alzheimer's disease (AD) attributable to the degeneration of medial temporal and parietal regions of the brain. In contrast, a somewhat paradoxical profile of relatively intact episodic memory, particularly for non-verbal material, is observed in semantic dementia (SD), despite marked atrophy of the hippocampus. This retrospective study investigated the neural substrates of episodic memory retrieval in 20 patients with a diagnosis of SD and 21 disease-matched cases of AD and compared their performance to that of 35 age- and education-matched healthy older Controls. Participants completed the Rey Complex Figure and the memory subscale of the Addenbrooke's Cognitive Examination-Revised as indices of visual and verbal episodic recall, respectively. Relative to Controls, AD patients showed compromised memory performance on both visual and verbal memory tasks. In contrast, memory deficits in SD were modality-specific occurring exclusively on the verbal task. Controlling for semantic processing ameliorated these deficits in SD, while memory impairments persisted in AD. Voxel-based morphometry analyses revealed significant overlap in the neural correlates of verbal episodic memory in AD and SD with predominantly anteromedial regions, including the bilateral hippocampus, strongly implicated. Controlling for semantic processing negated this effect in SD, however, a distributed network of frontal, medial temporal, and parietal regions was implicated in AD. Our study corroborates the view that episodic memory deficits in SD arise very largely as a consequence of the conceptual loading of traditional tasks. We propose that the functional integrity of frontal and parietal regions enables new learning to occur in SD in the face of significant hippocampal and anteromedial temporal lobe pathology, underscoring the inherent complexity of the episodic memory circuitry. Copyright © 2015

  1. Gene expression profile in temporal lobe epilepsy

    NARCIS (Netherlands)

    Aronica, Eleonora; Gorter, Jan A.

    2007-01-01

    Epilepsy is one of the most common neurological disorders. Temporal lobe epilepsy (TLE) represents the most frequent epilepsy syndrome in adult patients with resistance to pharmacological treatment. In TLE, the origin of seizure activity typically involves the hippocampal formation, which displays

  2. Gene expression profile in temporal lobe epilepsy.

    NARCIS (Netherlands)

    Aronica, E.M.A.; Gorter, J.A.

    2007-01-01

    Epilepsy is one of the most common neurological disorders. Temporal lobe epilepsy (TLE) represents the most frequent epilepsy syndrome in adult patients with resistance to pharmacological treatment. In TLE, the origin of seizure activity typically involves the hippocampal formation, which displays

  3. Formation of Bipolar Lobes by Jets

    Science.gov (United States)

    Soker, Noam

    2002-04-01

    I conduct an analytical study of the interaction of jets, or a collimated fast wind (CFW), with a previously blown asymptotic giant branch (AGB) slow wind. Such jets (or CFWs) are supposedly formed when a compact companion, a main-sequence star, or a white dwarf accretes mass from the AGB star, forms an accretion disk, and blows two jets. This type of flow, which I think shapes bipolar planetary nebulae (PNs), requires three-dimensional gasdynamical simulations, which are limited in the parameter space they can cover. By imposing several simplifying assumptions, I derive simple expressions which reproduce some basic properties of lobes in bipolar PNs and which can be used to guide future numerical simulations. I quantitatively apply the results to two proto-PNs. I show that the jet interaction with the slow wind can form lobes which are narrow close to, and far away from, the central binary system, and which are wider somewhere in between. Jets that are recollimated and have constant cross section can form cylindrical lobes with constant diameter, as observed in several bipolar PNs. Close to their source, jets blown by main-sequence companions are radiative; only further out they become adiabatic, i.e., they form high-temperature, low-density bubbles that inflate the lobes.

  4. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  5. Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Tracey A. Knaus

    2012-01-01

    Full Text Available Autism spectrum disorder (ASD is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years, matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.

  6. Particle doses in the pulmonary lobes of electronic and conventional cigarette users

    International Nuclear Information System (INIS)

    Manigrasso, Maurizio; Buonanno, Giorgio; Stabile, Luca; Morawska, Lidia; Avino, Pasquale

    2015-01-01

    The main aim of the present study was to estimate size segregated doses from e-cigarette aerosols as a function of the airway generation number in lung lobes. After a 2-second puff, 7.7 × 10 10 particles (D Tot ) with a surface area of 3.6 × 10 3  mm 2 (S Tot ), and 3.3 × 10 10 particles with a surface area of 4.2 × 10 3  mm 2 were deposited in the respiratory system for the electronic and conventional cigarettes, respectively. Alveolar and tracheobronchial deposited doses were compared to the ones received by non-smoking individuals in Western countries, showing a similar order of magnitude. Total regional doses (D R ), in head and lobar tracheobronchial and alveolar regions, ranged from 2.7 × 10 9 to 1.3 × 10 10 particles and 1.1 × 10 9 to 5.3 × 10 10 particles, for the electronic and conventional cigarettes, respectively. D R in the right-upper lung lobe was about twice that found in left-upper lobe and 20% greater in right-lower lobe than the left-lower lobe. - Highlights: • Lobar doses were compared for mainstreams of electronic and conventional cigarettes. • Aerosol doses from e-cigarettes were more than double that from conventional ones. • Doses from a 2-s puff exceed the daily doses of a no smoking Australian subject. • Highest deposition densities occurred at the lobar bronchi. • Aerosol deposition was greater in the right than in the left lung lobes. - Lobar bronchi and right lung lobes represent sites where effects of the aerosol from e-cigarette smoke may be more likely to occur

  7. Radiologic evaluation of right middle lobe collapse

    International Nuclear Information System (INIS)

    Kwun, Dae Young; Kim, Jong Deok; Kim, Jong Chul

    1989-01-01

    There are many pathogenetic factors for collapse of right middle lobe; profuse peribronchial clustering of lymph nodes about the right middle lobe bronchus, poor drainage of the bronchus because of its acute angle of take-off from the intermediate bronchus, and the isolation of this small lobe from the right upper and lower lobes, and thus from the aerating effects of collateral ventilation. Retrospectively we reviewed 36 cases of right of right middle lobe collapse of which causes were confirmed by histopathologic or bronchographic findings during the recent 6 years from March 1983 to February 1988 at Inje College Pusan Paik Hospital, and obtained the following results: 1. Male to female ratio was 1:1:4,and peak incidence (64%) was in the fifth and sixth decades with the mean age of 51.1 years. 2. Bronchiectasis was the most common cause (30.6%), and the others were chronic bronchitis (25.0%), pulmonary tuberculosis (19.4%), lung cancer (16.7%), and non-specific inflammatory disease (8.3%). This suggests benign disease is 5 times more common cause of right middle lobe collapse than lung cancer. 3. Among the plain chest radiolograph findings, obliteration of right cardiac border and triangular radiopaque density were the most frequent findings(77.8% in each) and the next was downward and anterior displacement of minor and major fissures (55.6%) 4. Bronchography was done in 11 cases; bronchiectasis was found in 8 cases and chronic bronchitis in 3 cases. Right middle lobe bronchus was obstructed in 2 cases of chronic bronchitis. 5. Chest CT scan was performed in 4 cases of lung cancer, 2 of non-specific inflammatory disease, and 1 of pulmonary tuberculosis: all of lung cancer revealed hilar mass, budged or lobulated fissures, in homogenous density, and mediastinal lymph node enlargement, and all benign disease showed homogenous density and flat to concave fissures. Right middle lobar bronchus narrowing was seen in 5 cases and its obstruction in 2 cases

  8. Dissociated roles of the parietal and frontal cortices in the scope and control of attention during visual working memory.

    Science.gov (United States)

    Li, Siyao; Cai, Ying; Liu, Jing; Li, Dawei; Feng, Zifang; Chen, Chuansheng; Xue, Gui

    2017-04-01

    Mounting evidence suggests that multiple mechanisms underlie working memory capacity. Using transcranial direct current stimulation (tDCS), the current study aimed to provide causal evidence for the neural dissociation of two mechanisms underlying visual working memory (WM) capacity, namely, the scope and control of attention. A change detection task with distractors was used, where a number of colored bars (i.e., two red bars, four red bars, or two red plus two blue bars) were presented on both sides (Experiment 1) or the center (Experiment 2) of the screen for 100ms, and participants were instructed to remember the red bars and to ignore the blue bars (in both Experiments), as well as to ignore the stimuli on the un-cued side (Experiment 1 only). In both experiments, participants finished three sessions of the task after 15min of 1.5mA anodal tDCS administered on the right prefrontal cortex (PFC), the right posterior parietal cortex (PPC), and the primary visual cortex (VC), respectively. The VC stimulation served as an active control condition. We found that compared to stimulation on the VC, stimulation on the right PPC specifically increased the visual WM capacity under the no-distractor condition (i.e., 4 red bars), whereas stimulation on the right PFC specifically increased the visual WM capacity under the distractor condition (i.e., 2 red bars plus 2 blue bars). These results suggest that the PPC and PFC are involved in the scope and control of attention, respectively. We further showed that compared to central presentation of the stimuli (Experiment 2), bilateral presentation of the stimuli (on both sides of the fixation in Experiment 1) led to an additional demand for attention control. Our results emphasize the dissociated roles of the frontal and parietal lobes in visual WM capacity, and provide a deeper understanding of the neural mechanisms of WM. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

    Science.gov (United States)

    Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

    2012-01-01

    Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency

  10. What is said or how it is said makes a difference: role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS.

    Science.gov (United States)

    van Rijn, Sophie; Aleman, André; van Diessen, Eric; Berckmoes, Celine; Vingerhoets, Guy; Kahn, René S

    2005-06-01

    Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total of 14 healthy volunteers participated in the present experiment, which involved transcranial magnetic stimulation (TMS) in combination with frameless stereotaxy. As predicted, compared with sham stimulation, TMS over the right fronto-parietal operculum differentially affected the reaction times for detection of emotional prosody vs. emotional semantics, showing that there is a dissociation at a neuroanatomical level. Detection of withdrawal emotions (fear and sadness) in prosody was delayed significantly by TMS. No effects of TMS were observed for approach emotions (happiness and anger). We propose that the right fronto-parietal operculum is not globally involved in emotion evaluation, but sensitive to specific forms of emotional discrimination and emotion types.

  11. Integrating what and when across the primate medial temporal lobe.

    Science.gov (United States)

    Naya, Yuji; Suzuki, Wendy A

    2011-08-05

    Episodic memory or memory for the detailed events in our lives is critically dependent on structures of the medial temporal lobe (MTL). A fundamental component of episodic memory is memory for the temporal order of items within an episode. To understand the contribution of individual MTL structures to temporal-order memory, we recorded single-unit activity and local field potential from three MTL areas (hippocampus and entorhinal and perirhinal cortex) and visual area TE as monkeys performed a temporal-order memory task. Hippocampus provided incremental timing signals from one item presentation to the next, whereas perirhinal cortex signaled the conjunction of items and their relative temporal order. Thus, perirhinal cortex appeared to integrate timing information from hippocampus with item information from visual sensory area TE.

  12. Severe atrophy of right hepatic lobe simulating right hepatic lobectomy

    International Nuclear Information System (INIS)

    Yeh, C.W.; Strashun, A.; Goldsmith, S.J.

    1981-01-01

    Absence of the right hepatic lobe following blunt abdominal trauma without surgical resection is reported. The usual site of the right hepatic lobe is demonstrated to be occupied by bowel by hepatobiliary imaging

  13. What is said or how it is said makes a difference : role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS

    NARCIS (Netherlands)

    van Rijn, S; Aleman, A; van Diessen, E; Berckmoes, C; Vingerhoets, G; Kahn, RS

    Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total

  14. The flexible use of multiple cue relationships in spatial navigation : A comparison of water maze performance following hippocampal, medial septal, prefrontal cortex, or posterior parietal cortex lesions

    NARCIS (Netherlands)

    Compton, DM; Griffith, HR; McDaniel, WF; Foster, RA; Davis, BK

    Rats prepared with lesions of the prefrontal cortex, posterior parietal cortex, hippocampus, or medial septal area were tested for acquisition of a number of variations of the open-field water maze using a version of place learning assessment described by Eichenbaum, Stewart, and Morris (1991).

  15. Ipsiversive ictal eye deviation in inferioposterior temporal lobe epilepsy-Two SEEG cases report.

    Science.gov (United States)

    Zhang, Wei; Liu, Xingzhou; Zuo, Lijun; Guo, Qiang; Chen, Qi; Wang, Yongjun

    2017-02-21

    Versive seizure characterized by conjugate eye movement during epileptic seizure has been considered commonly as one of the most valuable semiological signs for epilepsy localization, especially for frontal lobe epilepsy. However, the lateralizing and localizing significance of ictaleye deviation has been questioned by clinical observation of a series of focal epilepsy studies, including frontal, central, temporal, parietal and occipital epilepsy. Two epileptic cases characterized by ipsiversive eye deviation as initial clinical sign during the habitual epileptic seizures are presented in this paper. The localization of the epileptogenic zone of both of the cases has been confirmed as inferioposterior temporal region by the findings of ictalstereoelectroencephalography (SEEG) and a good result after epileptic surgery. Detailed analysis of the exact position of the key contacts of the SEEG electrodes identified the overlap between the location of the epileptogenic zone and human MT/MST complex, which play a crucial role in the control of smooth pursuit eye movement. Ipsiversive eye deviation could be the initial clinical sign of inferioposterior temporal lobe epilepsy and attribute to the involvement of human MT/MST complex, especially human MST whichwas located on the anterior/dorsal bank of the anterior occipital sulcus (AOS).

  16. Cognitive Functioning in Temporal Lobe Epilepsy: A BOLD-fMRI Study.

    Science.gov (United States)

    Guo, Lili; Bai, Genji; Zhang, Hui; Lu, Daoyan; Zheng, Jiyong; Xu, Gang

    2017-12-01

    We aimed to analyze the association between resting-state functional magnetic resonance imaging (re-fMRI) and cognitive function (including language, executive, and memory functions) in temporal lobe epilepsy (TLE) patients, which will help to explore the mechanism of brain function in patients. 15 TLE patients and 15 non-TLE patients were recruited. All subjects underwent neuropsychological testing and memory functional evaluation. Changes in verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), full intelligence quotient (FIQ), and memory quotient (MQ) were compared between two groups. Re-fMRI data were also collected from two groups to evaluate these changes. Each individual score of neuropsychological testing and memory functional evaluation were higher in control group, which was statistically different (all P temporal gyrus back, right superior temporal gyrus, left cerebellum, left angular gyrus, left wedge anterior lobe, and left central back; while the negatively activated brain regions were left prefrontal, right cerebellum, right corner back, and right anterior cingulate gyrus. During the language task, the activated brain regions of the TLE patients were right prefrontal lobe, the lateral temporal gyri, the left cerebellum, left cornu laterale gyrus, left precuneus, and the left postcentral gyrus, whereas the negatively activated brain areas were the left prefrontal cortex, the right cerebellum, right cornu laterale gyrus, and the right anterior cingulate gyrus. During the executive task, epilepsy patients showed activation difference in right prefrontal and right frontal lobe and right brain, left superior temporal gyrus, and right cerebellum anterior lobe compared with the control group; no negatively activated differences in brain areas. During the memory task, the difference lay in bilateral anterior cingulate gyrus and bilateral wedge anterior lobe while the negatively activated brain areas were the left inferior frontal

  17. Confabulation and memory impairments following frontal lobe lesions

    OpenAIRE

    Turner, Martha

    2005-01-01

    Neuroimaging studies have provided considerable evidence for frontal lobe involvement in memory processing. Memory impairments arc also frequently reported in patients with frontal lobe lesions. However detailed anatomical localisation is rare, making integration of lesion and imaging findings difficult. An investigation of the functional and anatomical contributions of the frontal lobes to memory was conducted in 42 patients with frontal lobe lesions, examining memory processes identified in...

  18. A Rare Case of Craniopharyngioma in the Temporal Lobe

    Directory of Open Access Journals (Sweden)

    Sasan Razmjoo

    2017-01-01

    Full Text Available Herein, we report on a rare case of craniopharyngioma arising in the left temporal lobe with no prior history of head trauma or surgery. There was a solid-cystic mass in the left temporal lobe on MR images. To the best of our knowledge, this is the second case of a craniopharyngioma occurring in the temporal lobe.

  19. Interleukin-17A Promotes Parietal Cell Atrophy by Inducing ApoptosisSummary

    Directory of Open Access Journals (Sweden)

    Kevin A. Bockerstett

    Full Text Available Background & Aims: Atrophic gastritis caused by chronic inflammation in the gastric mucosa leads to the loss of gastric glandular cells, including acid-secreting parietal cells. Parietal cell atrophy in a setting of chronic inflammation induces spasmolytic polypeptide expressing metaplasia, a critical step in gastric carcinogenesis. However, the mechanisms by which inflammation causes parietal cell atrophy and spasmolytic polypeptide expressing metaplasia are not well defined. We investigated the role of interleukin-17A (IL-17A in causing parietal cell atrophy. Methods: A mouse model of autoimmune atrophic gastritis was used to examine IL-17A production during early and late stages of disease. Organoids derived from corpus glands were used to determine the direct effects of IL-17A on gastric epithelial cells. Immunofluorescent staining was used to examine IL-17A receptors and the direct effect of signaling on parietal cells. Mice were infected with an IL-17A-producing adenovirus to determine the effects of IL-17A on parietal cells in vivo. Finally, IL-17A neutralizing antibodies were administered to mice with active atrophic gastritis to evaluate the effects on parietal cell atrophy and metaplasia. Results: Increased IL-17A correlated with disease severity in mice with chronic atrophic gastritis. IL-17A caused caspase-dependent gastric organoid degeneration, which could not be rescued with a necroptosis inhibitor. Parietal cells expressed IL-17A receptors and IL-17A treatment induced apoptosis in parietal cells. Overexpressing IL-17A in vivo induced caspase-3 activation and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining in parietal cells. Finally, IL-17A neutralizing antibody decreased parietal cell atrophy and metaplasia in mice with chronic atrophic gastritis. Conclusions: These data identify IL-17A as a cytokine that promotes parietal cell apoptosis during atrophic gastritis, a

  20. Human middle longitudinal fascicle: segregation and behavioral-clinical implications of two distinct fiber connections linking temporal pole and superior temporal gyrus with the angular gyrus or superior parietal lobule using multi-tensor tractography.

    Science.gov (United States)

    Makris, N; Preti, M G; Wassermann, D; Rathi, Y; Papadimitriou, G M; Yergatian, C; Dickerson, B C; Shenton, M E; Kubicki, M

    2013-09-01

    The middle longitudinal fascicle (MdLF) is a major fiber connection running principally between the superior temporal gyrus and the parietal lobe, neocortical regions of great biological and clinical interest. Although one of the most prominent cerebral association fiber tracts, it has only recently been discovered in humans. In this high angular resolution diffusion imaging (HARDI) MRI study, we delineated the two major fiber connections of the human MdLF, by examining morphology, topography, cortical connections, biophysical measures, volume and length in seventy-four brains. These two fiber connections course together through the dorsal temporal pole and the superior temporal gyrus maintaining a characteristic topographic relationship in the mediolateral and ventrodorsal dimensions. As these pathways course towards the parietal lobe, they split to form separate fiber pathways, one following a ventrolateral trajectory and connecting with the angular gyrus and the other following a dorsomedial route and connecting with the superior parietal lobule. Based on the functions of their cortical affiliations, we suggest that the superior temporal-angular connection of the MdLF, i.e., STG(MdLF)AG plays a role in language and attention, whereas the superior temporal-superior parietal connection of the MdLF, i.e., STG(MdLF)SPL is involved in visuospatial and integrative audiovisual functions. Furthermore, the MdLF may have clinical implications in neurodegenerative disorders such as primary progressive aphasia, frontotemporal dementia, posterior cortical atrophy, corticobulbar degeneration and Alzheimer's disease as well as attention-deficit/hyperactivity disorder and schizophrenia.

  1. Cingulate, Frontal and Parietal Cortical Dysfunction in Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Bush, George

    2011-01-01

    Functional and structural neuroimaging have identified abnormalities of the brain that are likely to contribute to the neuropathophysiology of attention-deficit/hyperactivity disorder (ADHD). In particular, hypofunction of the brain regions comprising the cingulo-frontal-parietal (CFP) cognitive-attention network have been consistently observed across studies. These are major components of neural systems that are relevant to ADHD, including cognitive/attention networks, motor systems and reward/feedback-based processing systems. Moreover, these areas interact with other brain circuits that have been implicated in ADHD, such as the “default mode” resting state network. ADHD imaging data related to CFP network dysfunction will be selectively highlighted here to help facilitate its integration with the other information presented in this special issue. Together, these reviews will help shed light on the neurobiology of ADHD. PMID:21489409

  2. Parietal and early visual cortices encode working memory content across mental transformations.

    Science.gov (United States)

    Christophel, Thomas B; Cichy, Radoslaw M; Hebart, Martin N; Haynes, John-Dylan

    2015-02-01

    Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Functional connectivity evidence of cortico-cortico inhibition in temporal lobe epilepsy.

    Science.gov (United States)

    Tracy, Joseph I; Osipowicz, Karol; Spechler, Philip; Sharan, Ashwini; Skidmore, Christopher; Doucet, Gaelle; Sperling, Michael R

    2014-01-01

    Epileptic seizures can initiate a neural circuit and lead to aberrant neural communication with brain areas outside the epileptogenic region. We focus on interictal activity in focal temporal lobe epilepsy and evaluate functional connectivity (FC) differences that emerge as function of bilateral versus strictly unilateral epileptiform activity. We assess the strength of FC at rest between the ictal and non-ictal temporal lobes, in addition to whole brain connectivity with the ictal temporal lobe. Results revealed strong connectivity between the temporal lobes for both patient groups, but this did not vary as a function of unilateral versus bilateral interictal status. Both the left and right unilateral temporal lobe groups showed significant anti-correlated activity in regions outside the epileptogenic temporal lobe, primarily involving the contralateral (non-ictal/non-pathologic) hemisphere, with precuneus involvement prominent. The bilateral groups did not show this contralateral anti-correlated activity. This anti-correlated connectivity may represent a form of protective and adaptive inhibition, helping to constrain epileptiform activity to the pathologic temporal lobe. The absence of this activity in the bilateral groups may be indicative of flawed inhibitory mechanisms, helping to explain their more widespread epileptiform activity. Our data suggest that the location and build up of epilepsy networks in the brain are not truly random, and are not limited to the formation of strictly epileptogenic networks. Functional networks may develop to take advantage of the regulatory function of structures such as the precuneus to instantiate an anti-correlated network, generating protective cortico-cortico inhibition for the purpose of limiting seizure spread or epileptogenesis. Copyright © 2012 Wiley Periodicals, Inc.

  4. Decreased functional connectivity and structural deficit in alertness network with right-sided temporal lobe epilepsy.

    Science.gov (United States)

    Gao, Yujun; Zheng, Jinou; Li, Yaping; Guo, Danni; Wang, Mingli; Cui, Xiangxiang; Ye, Wei

    2018-04-01

    Patients with temporal lobe epilepsy (TLE) often suffer from alertness alterations. However, specific regions connected with alertness remain controversial, and whether these regions have structural impairment is also elusive. This study aimed to investigate the characteristics and neural mechanisms underlying the functions and structures of alertness network in patients with right-sided temporal lobe epilepsy (rTLE) by performing the attentional network test (ANT), resting-state functional magnetic resonance imaging (R-SfMRI), and diffusion tensor imaging (DTI).A total of 47 patients with rTLE and 34 healthy controls underwent ANT, R-SfMRI, and DTI scan. The seed-based functional connectivity (FC) method and deterministic tractography were used to analyze the data.Patients with rTLE had longer reaction times in the no-cue and double-cue conditions. However, no differences were noted in the alertness effect between the 2 groups. The patient group had lower FC compared with the control group in the right inferior parietal lobe (IPL), amygdala, and insula. Structural deficits were found in the right parahippocampal gyrus, superior temporal pole, insula, and amygdala in the patient group compared with the control group. Also significantly negative correlations were observed between abnormal fractional anisotropy (between the right insula and the superior temporal pole) and illness duration in the patients with rTLE.The findings of this study suggested abnormal intrinsic and phasic alertness, decreased FC, and structural deficits within the alerting network in the rTLE. This study provided new insights into the mechanisms of alertness alterations in rTLE.

  5. Statistical parametric mapping for analyzing interictal magnetoencephalography in patients with left frontal lobe epilepsy.

    Science.gov (United States)

    Zhu, Haitao; Zhu, Jinlong; Bao, Forrest Sheng; Liu, Hongyi; Zhu, Xuchuang; Wu, Ting; Yang, Lu; Zou, Yuanjie; Zhang, Rui; Zheng, Gang

    2016-01-01

    Frontal lobe epilepsy is a common epileptic disorder and is characterized by recurring seizures that arise in the frontal lobes. The purpose of this study is to identify the epileptogenic regions and other abnormal regions in patients with left frontal lobe epilepsy (LFLE) based on the magnetoencephalogram (MEG), and to understand the effects of clinical variables on brain activities in patients with LFLE. Fifteen patients with LFLE (23.20 ± 8.68 years, 6 female and 9 male) and 16 healthy controls (23.13 ± 7.66 years, 6 female and 10 male) were included in resting-stage MEG examinations. Epileptogenic regions of LFLE patients were confirmed by surgery. Regional brain activations were quantified using statistical parametric mapping (SPM). The correlation between the activations of the abnormal brain regions and the clinical seizure parameters were computed for LFLE patients. Brain activations of LFLE patients were significantly elevated in left superior/middle/inferior frontal gyri, postcentral gyrus, inferior temporal gyrus, insula, parahippocampal gyrus and amygdala, including the epileptogenic regions. Remarkable decreased activations were found mainly in the left parietal gyrus and precuneus. There is a positive correlation between the duration of the epilepsy (in month) and activations of the abnormal regions, while no relation was found between age of seizure onset (year), seizure frequency and the regions of the abnormal activity of the epileptic patients. Our findings suggest that the aberrant brain activities of LFLE patients were not restricted to the epileptogenic zones. Long duration of epilepsy might induce further functional damage in patients with LFLE. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  6. Visual perception is dependent on visuospatial working memory and thus on the posterior parietal cortex.

    Science.gov (United States)

    Pisella, Laure

    2017-06-01

    Visual perception involves complex and active processes. We will start by explaining why visual perception is dependent on visuospatial working memory, especially the spatiotemporal integration of the perceived elements through the ocular exploration of visual scenes. Then we will present neuropsychology, transcranial magnetic stimulation and neuroimaging data yielding information on the specific role of the posterior parietal cortex of the right hemisphere in visuospatial working memory. Within the posterior parietal cortex, neuropsychology data also suggest that there might be dissociated neural substrates for deployment of attention (superior parietal lobules) and spatiotemporal integration (right inferior parietal lobule). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

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

    2015-03-17

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

  8. MR imaging of temporal lobe meningoencephalocele

    International Nuclear Information System (INIS)

    Tampieri, D.; Leblanc, R.; Melangon, D.; del-Carpio-O'Donovan, R.; Ethier, R.

    1991-01-01

    Basal meningoencephaloceles represent a rare entity, and they may be associated with a variety of midline cerebral abnormalities. The classification of basal meningoencephaloceles is related to their anatomic location. This paper reports experience in 3 patients, 2 who have temporal lobe epilepsy and a bone defect in the region of the foramen rotondum. In these 2 patients the encephalocele and its covering were protruding into the pterygopalatine fossa without any orbital involvement. The third patient presented with cerebrospinal fluid rhinorrhea caused by a transsphenoidal meningoencephalocele. MR imaging is the examination of choice for detecting these lesions since it allows for the visualization of the encephalocele and its meningeal covering as well as the bone defect and associated lesions in the temporal lobes

  9. Recurrent diarrhea as a manifestation of temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Tomohiko Murai

    2014-01-01

    Full Text Available A woman with temporal lobe epilepsy manifesting with repeated episodes of sudden diarrhea and loss of consciousness is reported. A 63-year-old, right-handed female presented with chief complaints of sudden diarrhea and loss of consciousness for almost three decades. The first attack occurred in her 30s, and similar attacks repeated several times in a year. Her attacks comprised abrupt abdominal discomfort, diarrhea, sudden emergence of old memories relating to when she had played with her brother in her childhood, and loss of consciousness during defecation. She had no convulsion or automatism and fully recovered in a few minutes. Every time she was transferred to emergency hospital by ambulance, she had examinations such as blood test, head computed tomography, electrocardiogram, abdominal ultrasound, and electroencephalography (EEG, but no specific diagnosis was made. On admission to our hospital, vital signs, neurological examination, and blood tests did not show abnormal findings. During long-term video-EEG monitoring for 40 h, she had no habitual event. Interictal EEG showed intermittent irregular delta waves and sharp regional transients in the left anterio-midtemporal area. Sharp transients were not as outstanding from background activities as to be defined as epileptiform discharges, but they were reproducible in morphology and distribution and appeared not only in sleep but also in wakefulness. Brain magnetic resonance imaging was unremarkable. Single-photon emission computed tomography showed a decrease of blood flow in the left frontal and temporal lobes. Wechsler Adult Intelligence Scale—III showed a decline of verbal comprehension. We concluded that the patient was suffering from partial epilepsy originating from the left temporal lobe. Carbamazepine markedly improved her seizures. Temporal lobe epilepsy can manifest with diverse autonomic symptoms and signs. Abdominal sensations often herald the onset of epileptic seizures

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

    Science.gov (United States)

    Mao, Junfeng; Wei, Shihui

    2013-06-01

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

  11. Temporal Lobe Epilepsy Surgery Failures: A Review

    Science.gov (United States)

    Harroud, Adil; Bouthillier, Alain; Weil, Alexander G.; Nguyen, Dang Khoa

    2012-01-01

    Patients with temporal lobe epilepsy (TLE) are refractory to antiepileptic drugs in about 30% of cases. Surgical treatment has been shown to be beneficial for the selected patients but fails to provide a seizure-free outcome in 20–30% of TLE patients. Several reasons have been identified to explain these surgical failures. This paper will address the five most common causes of TLE surgery failure (a) insufficient resection of epileptogenic mesial temporal structures, (b) relapse on the contralateral mesial temporal lobe, (c) lateral temporal neocortical epilepsy, (d) coexistence of mesial temporal sclerosis and a neocortical lesion (dual pathology); and (e) extratemporal lobe epilepsy mimicking TLE or temporal plus epilepsy. Persistence of epileptogenic mesial structures in the posterior temporal region and failure to distinguish mesial and lateral temporal epilepsy are possible causes of seizure persistence after TLE surgery. In cases of dual pathology, failure to identify a subtle mesial temporal sclerosis or regions of cortical microdysgenesis is a likely explanation for some surgical failures. Extratemporal epilepsy syndromes masquerading as or coexistent with TLE result in incomplete resection of the epileptogenic zone and seizure relapse after surgery. In particular, the insula may be an important cause of surgical failure in patients with TLE. PMID:22934162

  12. Occipital lobe infarction and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-08-01

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

  13. Occipital lobe infarction and positron emission tomography

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Nagata, Ken; Shishido, Fumio

    1990-01-01

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

  14. CT anatomy of para-caval portion of the caudate lobe of the liver

    International Nuclear Information System (INIS)

    Matsui, Osamu; Takashima, Tsutomu; Kadoya, Masumi; Hirose, Jinichiro; Kameyama, Tomiaki; Choto, Shuichi; Konishi, Hideo

    1988-01-01

    Computed tomographic (CT) anatomy of the right border of the caudate lobe had been unclear. Recently, Kumon studied in full detail the anatomy of the caudate branches of the portal vein by corrosion liver cast study and revealed the para-caval portion (PCP) of the caudate lobe extending just right to the Spiegel lobe from the caudate process to the area between the roots of the right and middle hepatic veins. According to Kumon's study, we analyzed the perfusion defects seen on CT during arterial portography performed in patients with intrahepatic portal vein obstruction and studied CT anatomy of PCP. As a result, we consider that the area between the roots of the right and middle hepatic veins belongs to PCP in more than 70 % of patients. Therefore, we think that the area between the roots of the right and middle hepatic veins which had been classified as being in the anterior suprior area (S 8 ) should be reclassified as being in the caudate lobe (S 1 ). (author)

  15. CT anatomy of para-caval portion of the caudate lobe of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Osamu; Takashima, Tsutomu; Kadoya, Masumi; Hirose, Jinichiro; Kameyama, Tomiaki; Choto, Shuichi; Konishi, Hideo

    1988-07-01

    Computed tomographic (CT) anatomy of the right border of the caudate lobe had been unclear. Recently, Kumon studied in full detail the anatomy of the caudate branches of the portal vein by corrosion liver cast study and revealed the para-caval portion (PCP) of the caudate lobe extending just right to the Spiegel lobe from the caudate process to the area between the roots of the right and middle hepatic veins. According to Kumon's study, we analyzed the perfusion defects seen on CT during arterial portography performed in patients with intrahepatic portal vein obstruction and studied CT anatomy of PCP. As a result, we consider that the area between the roots of the right and middle hepatic veins belongs to PCP in more than 70 % of patients. Therefore, we think that the area between the roots of the right and middle hepatic veins which had been classified as being in the anterior suprior area (S/sub 8/) should be reclassified as being in the caudate lobe (S/sub 1/).

  16. Syntactic Structure Building in the Anterior Temporal Lobe during Natural Story Listening

    Science.gov (United States)

    Brennan, Jonathan; Nir, Yuval; Hasson, Uri; Malach, Rafael; Heeger, David J.; Pylkkanen, Liina

    2012-01-01

    The neural basis of syntax is a matter of substantial debate. In particular, the inferior frontal gyrus (IFG), or Broca's area, has been prominently linked to syntactic processing, but the anterior temporal lobe has been reported to be activated instead of IFG when manipulating the presence of syntactic structure. These findings are difficult to…

  17. Evaluation of Posterior Hippocampal Epileptogenicity During Epilepsy Surgery For Temporal Lobe Cavernoma by the Occipital Approach.

    Science.gov (United States)

    Akiyama, Yukinori; Suzuki, Kengo; Ochi, Satoko; Miyamoto, Susumu; Mikuni, Nobuhiro

    2015-11-01

    Cavernomas frequently are associated with intractable epilepsy. When cavernomas located in the temporal lobe are associated with intractable epilepsy, the hippocampus also may have an epileptic focus. The objective in the present study was to clarify the importance of evaluation of the posterior hippocampal epileptogenicity during epilepsy surgery for posteromedial temporal lobe cavernoma. In this study, we describe 2 rare cases of medically intractable epilepsy in patients with posteromedial temporal lobe cavernomas who underwent surgery via the occipital approach. Using longitudinal insertion of depth electrodes into the hippocampus, we evaluated epileptogenicity in both patients from the cavernoma cavity and its surrounding hemosiderin, as well as from the posterior hippocampus near the cavernoma. We show that the transoccipital approach to the posteromedial temporal lobe is compatible with depth electrode insertion and subdural electrode placement on the temporal lobe, enabling an accurate evaluation of potential epileptogenic zones in the posterior part of the hippocampus. Both patients did not experience any seizures and had no postoperative neurologic deficits, and their cognitive functions were intact. The transoccipital approach enables the optimization of the extent of posterior hippocampectomy while avoiding unnecessary resection for seizure control. We suggest resecting the posterior part of the hippocampus in addition to the cavernoma and surrounding areas in patients with medically refractory epilepsy due to a posteromedial temporal cavernoma. Tailored systematic resection guided by intraoperative electrocorticography and electroencephalography with a depth electrode was important and necessary in the present cases. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Temporal lobe epilepsy: Comparison of CT and MR in 100 patients

    International Nuclear Information System (INIS)

    Schoerner, W.; Meencke, H.J.; Sander, B.; Henkes, H.; Felix, R.; Klinikum Rudolf Virchow, Berlin

    1989-01-01

    The value of CT and MR was studied in 100 patients with temporal lobe epilepsy. Axial CT scans were obtained before and after contrast injection. Coronary MR scans were carried out with T 1 -(SE 400/30, GE 315/14) and T 2 -weighted sequences (SE 1600/30 + 70). A circumscribed lesion was demonstrated in fifteen patients by CT and in 25 patients by MR. With the exception of a small area of calcification, all lesions seen on CT could also be recognized on MR. Better sensitivity and improved demonstration of the temporal lobes makes MR the method of choice in the diagnosis of temporal lobe epilepsy. (orig./GDG) [de

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

    Science.gov (United States)

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

    2017-01-09

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

  20. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H{sub 2}{sup 15}O PET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2002-06-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H{sub 2}{sup 15}O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

  1. Clinical study on temporal lobe epilepsy in childhood caused by temporal lobe space occupying lesions

    International Nuclear Information System (INIS)

    Matsuura, Mariko; Oguni, Hirokazu; Funatsuka, Makoto; Osawa, Makiko; Yamane, Fumitaka; Hori, Tomokatsu; Shimizu, Hiroyuki

    2008-01-01

    We studied the clinicoelectrical and neuroimaging features of 11 patients with symptomatic temporal lobe epilepsy (TLE) caused by temporal lobe space occupying lesions (SOLs), and compared its characteristics with those of 19 mesial TLE (MTLE) patients. Brain MRI demonstrated SOLs in the mesiotemporal lobe in 9, and laterotemporal lobe in the remaining 2 patients. Ten of the 11 patients successfully underwent surgery, which revealed tumors in 7 and focal cortical dysplasia in 3 patients. Comparisons of the clinical features between those with space occupying TLE (SOTLE) and MTLE showed that both conditions shared the same clinical seizure manifestations such as gastric uprising sensation or ictal fear and a favorable response to surgery. However, the patients with SOTLE had fewer febrile convulsion, and more frequent seizure recurrences as well as TLE EEG discharges and associations of the monophasic clinical course than those with MTLE. In addition, the MRI findings were characterized by unilateral hippocampal atrophy in MTLE and expanding or SOLs in the SOTLE group. Children with complex partial seizures of suspected temporal lobe origin should undergo extensive neuroimaging evaluation. (author)

  2. Broca's area network in language function.Broca's area network in language function: A pooling-data connectivity study

    Directory of Open Access Journals (Sweden)

    Byron eBernal

    2015-05-01

    Full Text Available Background and Objective. Modern neuroimaging developments have demonstrated that cognitive functions correlate with brain networks rather than specific areas. The purpose of this paper was to analyze the connectivity of Broca's area based on language tasks. Methods. A connectivity modeling study was performed by pooling data of Broca's activation in language tasks. Fifty-seven papers that included 883 subjects in 84 experiments were analyzed. Analysis of Likelihood Estimates of pooled data was utilized to generate the map; thresholds at p < 0.01 were corrected for multiple comparisons and false discovery rate. Resulting images were co-registered into MNI standard space. Results. A network consisting of 16 clusters of activation was obtained. Main clusters were located in the frontal operculum, left posterior temporal region, supplementary motor area, and the parietal lobe. Less common clusters were seen in the sub-cortical structures including the left thalamus, left putamen, secondary visual areas and the right cerebellum. Conclusions. BA44-related networks involved in language processing were demonstrated utilizing a pooling-data connectivity study. Significance, interpretation and limitations of the results are discussed.

  3. Mismatch between the eye and the optic lobe in the giant squid.

    Science.gov (United States)

    Liu, Yung-Chieh; Liu, Tsung-Han; Yu, Chun-Chieh; Su, Chia-Hao; Chiao, Chuan-Chin

    2017-07-01

    Giant squids ( Architeuthis ) are a legendary species among the cephalopods. They live in the deep sea and are well known for their enormous body and giant eyes. It has been suggested that their giant eyes are not adapted for the detection of either mates or prey at distance, but rather are best suited for monitoring very large predators, such as sperm whales, at distances exceeding 120 m and at a depth below 600 m (Nilsson et al. 2012 Curr. Biol. 22 , 683-688. (doi:10.1016/j.cub.2012.02.031)). However, it is not clear how the brain of giant squids processes visual information. In this study, the optic lobe of a giant squid ( Architeuthis dux , male, mantle length 89 cm), which was caught by local fishermen off the northeastern coast of Taiwan, was scanned using high-resolution magnetic resonance imaging in order to examine its internal structure. It was evident that the volume ratio of the optic lobe to the eye in the giant squid is much smaller than that in the oval squid ( Sepioteuthis lessoniana ) and the cuttlefish ( Sepia pharaonis ). Furthermore, the cell density in the cortex of the optic lobe is significantly higher in the giant squid than in oval squids and cuttlefish, with the relative thickness of the cortex being much larger in Architeuthis optic lobe than in cuttlefish. This indicates that the relative size of the medulla of the optic lobe in the giant squid is disproportionally smaller compared with these two cephalopod species. This morphological study of the giant squid brain, though limited only to the optic lobe, provides the first evidence to support that the optic lobe cortex, the visual information processing area in cephalopods, is well developed in the giant squid. In comparison, the optic lobe medulla, the visuomotor integration centre in cephalopods, is much less developed in the giant squid than other species. This finding suggests that, despite the giant eye and a full-fledged cortex within the optic lobe, the brain of giant

  4. Separating recognition processes of declarative memory via anodal tDCS: boosting old item recognition by temporal and new item detection by parietal stimulation.

    Science.gov (United States)

    Pisoni, Alberto; Turi, Zsolt; Raithel, Almuth; Ambrus, Géza Gergely; Alekseichuk, Ivan; Schacht, Annekathrin; Paulus, Walter; Antal, Andrea

    2015-01-01

    There is emerging evidence from imaging studies that parietal and temporal cortices act together to achieve successful recognition of declarative information; nevertheless, the precise role of these regions remains elusive. To evaluate the role of these brain areas in declarative memory retrieval, we applied bilateral tDCS, with anode over the left and cathode over the right parietal or temporal cortices separately, during the recognition phase of a verbal learning paradigm using a balanced old-new decision task. In a parallel group design, we tested three different groups of healthy adults, matched for demographic and neurocognitive status: two groups received bilateral active stimulation of either the parietal or the temporal cortex, while a third group received sham stimulation. Accuracy, discriminability index (d') and reaction times of recognition memory performance were measurements of interest. The d' sensitivity index and accuracy percentage improved in both active stimulation groups, as compared with the sham one, while reaction times remained unaffected. Moreover, the analysis of accuracy revealed a different effect of tDCS for old and new item recognition. While the temporal group showed enhanced performance for old item recognition, the parietal group was better at correctly recognising new ones. Our results support an active role of both of these areas in memory retrieval, possibly underpinning different stages of the recognition process.

  5. Attention enhances multi-voxel representation of novel objects in frontal, parietal and visual cortices.

    Science.gov (United States)

    Woolgar, Alexandra; Williams, Mark A; Rich, Anina N

    2015-04-01

    Selective attention is fundamental for human activity, but the details of its neural implementation remain elusive. One influential theory, the adaptive coding hypothesis (Duncan, 2001, An adaptive coding model of neural function in prefrontal cortex, Nature Reviews Neuroscience 2:820-829), proposes that single neurons in certain frontal and parietal regions dynamically adjust their responses to selectively encode relevant information. This selective representation may in turn support selective processing in more specialized brain regions such as the visual cortices. Here, we use multi-voxel decoding of functional magnetic resonance images to demonstrate selective representation of attended--and not distractor--objects in frontal, parietal, and visual cortices. In addition, we highlight a critical role for task demands in determining which brain regions exhibit selective coding. Strikingly, representation of attended objects in frontoparietal cortex was highest under conditions of high perceptual demand, when stimuli were hard to perceive and coding in early visual cortex was weak. Coding in early visual cortex varied as a function of attention and perceptual demand, while coding in higher visual areas was sensitive to the allocation of attention but robust to changes in perceptual difficulty. Consistent with high-profile reports, peripherally presented objects could also be decoded from activity at the occipital pole, a region which corresponds to the fovea. Our results emphasize the flexibility of frontoparietal and visual systems. They support the hypothesis that attention enhances the multi-voxel representation of information in the brain, and suggest that the engagement of this attentional mechanism depends critically on current task demands. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

    Science.gov (United States)

    Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

    2013-09-01

    Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

  7. Magnetic resonance imaging in temporal lobe epilepsy. Usefulness for the etiological diagnosis of temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Mohamed, A.; Lueders, H.O.

    2000-01-01

    With improvement in magnetic resonance (MR) imaging techniques, the ability to identify lesions responsible for temporal lobe epilepsy has increased. MR imaging has also enabled the in vivo diagnosis of hippocampal sclerosis. Brain tumors are responsible for 2-4% of epilepsies in adult population and 10-20% of medically intractable epilepsy. The sensitivity of MR imaging in the diagnosis of tumors and other lesions of the temporal lobe (vascular malformations, etc.) is around 90%. Both hippocampal sclerosis and other temporal lobe lesions are amenable to surgical therapy with excellent postsurgical seizure outcome. In this article, we characterize and underline distinguishing features of the different pathological entities. We also suggest an approach to reviewing the MR images of an epileptic patient. (author)

  8. Aspirin induces morphological transformation to the secretory state in isolated rabbit parietal cells.

    Science.gov (United States)

    Murthy, U K; Levine, R A

    1991-08-01

    The morphological response of rabbit parietal cells to aspirin was evaluated by grading several ultra-structural features including the extent of the tubulovesicular system, intracellular secretory canaliculi, and microvilli. After exposure of isolated parietal cells and gastric glands to aspirin or histamine, there was an approximately twofold increase in the ratio of secretory to nonsecretory parietal cells, and depletion of extracellular Ca2+ abolished the aspirin-induced morphological changes. Morphometry in parietal cells showed that aspirin induced a sixfold increase in secretory canalicular membrane elaboration. Aspirin potentiated histamine-induced parietal cell respiration and aminopyrine uptake ratio but did not increase basal respiration or aminopyrine uptake, suggesting an apparent dissociation from aspirin-induced morphological changes.

  9. Normal variation of focal T2 Hyperintensities in anterior parietal periventricular white matter: Another 'Terminal Zones of Myelination'

    International Nuclear Information System (INIS)

    Park, Jong Oag; Woo, Je Ho; Ki, Tae Sung; Lee, Jong Hwa; Chung, Jin Woo; Lee, Don Young

    1994-01-01

    It has been known that there are several areas of T2 hyperintensity in normal white matter of brain, such as terminal zones of myelination, ependymitis granularis, ones of posterior internal capsule, and perivascular space. The aim of our study is to demonstrate another region of T2 hyperintensities in normal pediatric age group. We have studied brain MR for 10 normal volunteers and 35 patients without having intracranial lesions in pediatric age group(3-19 years). In 5 among 45 cases, focal T2 hyperintensities were seen in the parietal periventricular white matter beneath the postcentral gyri. They were noted as poorly defined, 5-10 mm sized areas of increased signal intensities on T2-weighted axial images. They were also characterized by bilateral, posteromedially oriented, short band-like or oval areas. Interestingly, they were directly continuous with the T2 hyperintensity of posterior internal capsule. In spite of the relatively highly frequency in the pediatric population as in our study, this finding has not been reported in the asymptomatic adults. The results show that the bilateral anterior parietal hyperintense areas may be another terminal zones of delayed myelination affecting the parietopontine tract. They should be differentiated from pathologic T2 hyperintensities by their characteristic findings

  10. Regional glucose metabolism within cortical Brodmann areas in healthy individuals and autistic patients.

    Science.gov (United States)

    Hazlett, Erin A; Buchsbaum, Monte S; Hsieh, Pauline; Haznedar, M Mehmet; Platholi, Jimcy; LiCalzi, Elizabeth M; Cartwright, Charles; Hollander, Eric

    2004-01-01

    A new Brodmann area (BA) delineation approach was applied to FDG-PET scans of autistic patients and healthy volunteers (n = 17 in each group) to examine relative glucose metabolism (rGMR) during performance of a verbal memory task. In the frontal lobe, patients had lower rGMR in medial/cingulate regions (BA 32, 24, 25) but not in lateral regions (BA 8-10) compared with healthy controls. Patients had higher rGMR in occipital (BA 19) and parietal regions (BA 39) compared with controls, but there were no group differences in temporal lobe regions. Among controls, better recall and use of the semantic-clustering strategy was associated with greater lateral and medial frontal rGMR, while decreased rGMR in medial-frontal regions was associated with greater perseverative/intrusion errors. Patients failed to show these patterns. Autism patients have dysfunction in some but not all of the key brain regions subserving verbal memory performance, and other regions may be recruited for task performance. Copyright 2004 S. Karger AG, Basel

  11. Attention as the 'glue' for object integration in parietal extinction.

    Science.gov (United States)

    Conci, Markus; Groß, Julia; Keller, Ingo; Müller, Hermann J; Finke, Kathrin

    2018-04-01

    Patients with unilateral, parietal brain damage frequently show visual extinction, which manifests in a failure to identify contralesional stimuli when presented simultaneously with other, ipsilesional stimuli (but full awareness for single stimulus presentations). Extinction reflects an impairment of spatial selective attention, leaving basic preattentive processing unaffected. For instance, access to bilaterally grouped objects is usually spared in extinction, suggesting that grouping occurs at a stage preceding (in the patients: abnormally biased) spatial-attentional selection. Here, we reinvestigated this notion by comparing (largely between participants, but also within a single-case participant) conditions with objects that varied in their dominant direction of grouping: from the attended to the non-attended hemifield (data from Conci et al., 2009) versus from the non-attended to the attended hemifield (new data). We observe complete absence of extinction when shape completion extended from the attended hemifield. By contrast, extinction was not diminished when object groupings propagate from the unattended hemifield. Moreover, we found the individual severity of the attentional impairment (assessed by a standard "inattention" test) to be directly related to the degree of completion in the unattended hemifield. This pattern indicates that grouping can overcome visual extinction only when object integration departs from the attended visual field, implying, contrary to many previous accounts, that attention is crucial for grouping to be initiated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Subtotal Ablation of Parietal Epithelial Cells Induces Crescent Formation

    Science.gov (United States)

    Sicking, Eva-Maria; Fuss, Astrid; Uhlig, Sandra; Jirak, Peggy; Dijkman, Henry; Wetzels, Jack; Engel, Daniel R.; Urzynicok, Torsten; Heidenreich, Stefan; Kriz, Wilhelm; Kurts, Christian; Ostendorf, Tammo; Floege, Jürgen; Smeets, Bart

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established an inducible transgenic mouse to allow subtotal ablation of PECs. Proteinuria developed during doxycycline-induced cellular ablation but fully reversed 26 days after termination of doxycycline administration. The ablation of PECs was focal, with only 30% of glomeruli exhibiting histologic changes; however, the number of PECs was reduced up to 90% within affected glomeruli. Ultrastructural analysis revealed disruption of PEC plasma membranes with cytoplasm shedding into Bowman’s space. Podocytes showed focal foot process effacement, which was the most likely cause for transient proteinuria. After >9 days of cellular ablation, the remaining PECs formed cellular extensions to cover the denuded Bowman’s capsule and expressed the activation marker CD44 de novo. The induced proliferation of PECs persisted throughout the observation period, resulting in the formation of typical cellular crescents with periglomerular infiltrate, albeit without accompanying proteinuria. In summary, subtotal ablation of PECs leads the remaining PECs to react with cellular activation and proliferation, which ultimately forms cellular crescents. PMID:22282596

  13. Parietal cells-new perspectives in glomerular disease.

    Science.gov (United States)

    Miesen, Laura; Steenbergen, Eric; Smeets, Bart

    2017-07-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertaining to the maintenance of the filtration barrier and transport, respectively. For PECs, no specific function other than a structural one has been known until recently. Possible important functions for PECs in the fate of the glomerulus in glomerular disease have now become apparent: (1) PECs may be involved in the replacement of lost podocytes; (2) PECs form the basis of extracapillary proliferative lesions and subsequent sclerosis in glomerular disease. In addition to the acknowledgement that PECs are crucial in glomerular disease, knowledge has been gained regarding the molecular processes driving the phenotypic changes and behavior of PECs. Understanding these molecular processes is important for the development of specific therapeutic approaches aimed at either stimulation of the regenerative function of PECs or inhibition of the pro-sclerotic action of PECs. In this review, we discuss recent advances pertaining to the role of PECs in glomerular regeneration and disease and address the major molecular processes involved.

  14. The regenerative potential of parietal epithelial cells in adult mice.

    Science.gov (United States)

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

    2014-04-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman's capsule expressed podocyte markers, and cells on Bowman's capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman's capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman's capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman's capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans.

  15. Gray, White Matter Concentration Changes and Their Correlation with Heterotopic Neurons in Temporal Lobe Epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk; Joo, Eun Yun; Kim, Sung Tae; Hong, Seung Bong [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2010-02-15

    To identify changes in gray and white matter concentrations (GMC, WMC), and their relation to heterotopic neuron numbers in mesial temporal lobe epilepsy (mTLE). The gray matter or white matter concentrations of 16 left and 15 right mTLE patients who achieved an excellent surgical outcome were compared with those of 24 healthy volunteers for the left group and with 23 healthy volunteers for the right group, by optimized voxel-based morphometry using unmodulated and modulated images. A histologic count of heterotopic neurons was obtained in the white matter of the anterior temporal lobe originating from the patients' surgical specimens. In addition, the number of heterotopic neurons were tested to determine if there was a correlation with the GMC or WMC. The GMCs of the left and right mTLE groups were reduced in the ipsilateral hippocampi, bilateral thalami, precentral gyri, and in the cerebellum. The WMCs were reduced in the ipsilateral white matter of the anterior temporal lobe, bilateral parahippocampal gyri, and internal capsules, but increased in the pons and bilateral precentral gyri. The heterotopic neuron counts in the left mTLE group showed a positive correlation (r = 0.819, p < 0.0001) with GMCs and a negative correlation (r = - 0.839, p < 0.0001) with WMCs in the white matter of the anterior temporal lobe. The present study shows the abnormalities of the cortico-thalamo- hippocampal network including a gray matter volume reduction in the anterior frontal lobes and an abnormality of brain tissue concentration in the pontine area. Furthermore, heterotopic neuron numbers were significantly correlated with GMC or WMC in the left white matter of anterior temporal lobe.

  16. Alterations of whole-brain cortical area and thickness in mild cognitive impairment and Alzheimer's disease.

    Science.gov (United States)

    Li, Chuanming; Wang, Jian; Gui, Li; Zheng, Jian; Liu, Chen; Du, Hanjian

    2011-01-01

    Gray matter volume and density of several brain regions, determined by magnetic resonance imaging (MRI), are decreased in Alzheimer's disease (AD). Animal studies have indicated that changes in cortical area size is relevant to thinking and behavior, but alterations of cortical area and thickness in the brains of individuals with AD or its likely precursor, mild cognitive impairment (MCI), have not been reported. In this study, 25 MCI subjects, 30 AD subjects, and 30 age-matched normal controls were recruited for brain MRI scans and Functional Activities Questionnaire (FAQ) assessments. Based on the model using FreeSurfer software, two brain lobes were divided into various regions according to the Desikan-Killiany atlas and the cortical area and thickness of every region was compared and analyzed. We found a significant increase in cortical area of several regions in the frontal and temporal cortices, which correlated negatively with MMSE scores, and a significant decrease in cortical area of several regions in the parietal cortex and the cingulate gyrus in AD subjects. Increased cortical area was also seen in some regions of the frontal and temporal cortices in MCI subjects, whereas the cortical thickness of the same regions was decreased. Our observations suggest characteristic differences of the cortical area and thickness in MCI, AD, and normal control subjects, and these changes may help diagnose both MCI and AD.

  17. Peninsula Effects on Birds in a Coastal Landscape: Are Coves More Species Rich than Lobes?

    Directory of Open Access Journals (Sweden)

    Sam Riffell

    2012-10-01

    Full Text Available Peninsula effects - decreasing richness with increasing distance along peninsula lobes - have been identified for many taxa on large peninsulas. Peninsula effects are caused by differences in colonization and extinction predicted by island biogeography or by environmental gradients along the peninsula. We compared species-area regressions for cove patches (i.e., mainland to regressions for lobe patches (i.e., on peninsula tips for wet meadow birds along a highly interdigitated shoreline (northern Lake Huron, USA. We conducted analysis both with and without accounting for variation in habitat and landscape characteristics (i.e., environmental gradients of wet meadows. Species-area regressions for coves did not differ from lobes, nor did these results differ when we accounted for gradients. Similarly, few species were more abundant in coves. Peninsula effects may have been lacking because lobe patches were located ≈ 800 m on average from the mainland, and birds are highly mobile and can easily sample patches over these distances. One important caveat was that wet meadow patches > 5 ha were located in coves, so coves would still be important considerations in conservation plans because of the contribution of large patches to reproductive success, dispersal and population dynamics.

  18. Origin of parietal podocytes in atubular glomeruli mapped by lineage tracing.

    Science.gov (United States)

    Schulte, Kevin; Berger, Katja; Boor, Peter; Jirak, Peggy; Gelman, Irwin H; Arkill, Kenton P; Neal, Christopher R; Kriz, Wilhelm; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

    2014-01-01

    Parietal podocytes are fully differentiated podocytes lining Bowman's capsule where normally only parietal epithelial cells (PECs) are found. Parietal podocytes form throughout life and are regularly observed in human biopsies, particularly in atubular glomeruli of diseased kidneys; however, the origin of parietal podocytes is unresolved. To assess the capacity of PECs to transdifferentiate into parietal podocytes, we developed and characterized a novel method for creating atubular glomeruli by electrocoagulation of the renal cortex in mice. Electrocoagulation produced multiple atubular glomeruli containing PECs as well as parietal podocytes that projected from the vascular pole and lined Bowman's capsule. Notably, induction of cell death was evident in some PECs. In contrast, Bowman's capsules of control animals and normal glomeruli of electrocoagulated kidneys rarely contained podocytes. PECs and podocytes were traced by inducible and irreversible genetic tagging using triple transgenic mice (PEC- or Pod-rtTA/LC1/R26R). Examination of serial cryosections indicated that visceral podocytes migrated onto Bowman's capsule via the vascular stalk; direct transdifferentiation from PECs to podocytes was not observed. Similar results were obtained in a unilateral ureter obstruction model and in human diseased kidney biopsies, in which overlap of PEC- or podocyte-specific antibody staining indicative of gradual differentiation did not occur. These results suggest that induction of atubular glomeruli leads to ablation of PECs and subsequent migration of visceral podocytes onto Bowman's capsule, rather than transdifferentiation from PECs to parietal podocytes.

  19. Occurrence of the lobe plasma at lunar distance

    International Nuclear Information System (INIS)

    Hardy, D.A.; Hills, H.K.; Freeman, J.W.

    1979-01-01

    Recent analysis has confirmed and expanded the characterization of the lobe plasma, the extension of the 'boundary layer' and 'plasma mantle' to lunar distances. Careful statistical analysis has verified that Magnetic Field (1MF). When the moon is in the dawnside of the northern lobe or duskside of the southern lobe, the probability for observation of the lobe plasma is greatly increased when, in the hour preceding, the IMF has had a positive y component. Conversely, when the moon is in the duskside of the northern lobe or dawnside of the southern lobe, the probability for observation is much increased when the IMF has a negative y component. Analysis of lobe plasma data in conjunction with high time resolution IMF data has shown the probability of observation also is greater with a southward pointing IMF. The observed correlations with the y and z components the IMF reflect the fact that the asymmetry and changes in magnitude of the polar cap electric field induced by the IMF extends to lunar distances and determines the depth into the tail to which the ions can drift. Generally, the lobe plasma is observed sporadically for a full day after the moon has entered the tail and a full day before the last magnetopause crossing as it exits the tail. An average extent of approx.8--10R/sub e/ inward from the magnetopause is inferred; however, the lobe plasma has been seen all across the tail

  20. Surgical Considerations of Intractable Mesial Temporal Lobe Epilepsy

    Science.gov (United States)

    Boling, Warren W.

    2018-01-01

    Surgery of temporal lobe epilepsy is the best opportunity for seizure freedom in medically intractable patients. The surgical approach has evolved to recognize the paramount importance of the mesial temporal structures in the majority of patients with temporal lobe epilepsy who have a seizure origin in the mesial temporal structures. For those individuals with medically intractable mesial temporal lobe epilepsy, a selective amygdalohippocampectomy surgery can be done that provides an excellent opportunity for seizure freedom and limits the resection to temporal lobe structures primarily involved in seizure genesis. PMID:29461485

  1. Surgical Considerations of Intractable Mesial Temporal Lobe Epilepsy

    Directory of Open Access Journals (Sweden)

    Warren W. Boling

    2018-02-01

    Full Text Available Surgery of temporal lobe epilepsy is the best opportunity for seizure freedom in medically intractable patients. The surgical approach has evolved to recognize the paramount importance of the mesial temporal structures in the majority of patients with temporal lobe epilepsy who have a seizure origin in the mesial temporal structures. For those individuals with medically intractable mesial temporal lobe epilepsy, a selective amygdalohippocampectomy surgery can be done that provides an excellent opportunity for seizure freedom and limits the resection to temporal lobe structures primarily involved in seizure genesis.

  2. Channel systems and lobe construction in the Mississippi Fan

    Science.gov (United States)

    Garrison, L. E.; Kenyon, Neil H.; Bouma, A.H.

    1982-01-01

    Morphological features on the Mississippi Fan in the eastern Gulf of Mexico were mapped using GLORIA II, a long-range side-scan sonar system. Prominent is a sinuous channel flanked by well-developed levees and occasional crevasse splays. The channel follows the axis and thickest part of the youngest fan lobe; seismic-reflection profiles offer evidence that its course has remained essentially constant throughout lobe development. Local modification and possible erosion of levees by currents indicates a present state of inactivity. Superficial sliding has affected part of the fan lobe, but does not appear to have been a factor in lobe construction. ?? 1982 A. M. Dowden, Inc.

  3. Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

    International Nuclear Information System (INIS)

    Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van

    2008-01-01

    Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H + /K + ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H + /K + ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H + /K + ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H + /K + ATPase which underpin the regulation of acid secretion

  4. Parietal lesions produce illusory conjunction errors in rats

    Directory of Open Access Journals (Sweden)

    Raymond PIERRE Kesner

    2012-05-01

    Full Text Available When several different objects are presented, visual objects are perceived correctly only if their features are identified and then bound together. Illusory-conjunction errors result when an object is correctly identified but is combined incorrectly. The parietal cortex (PPC has been shown repeatedly to play an important role in feature binding. The present study builds on a series of recent studies that have made use of visual search paradigms to elucidate the neural system involved in feature binding. This experiment attempts to define the role the PPC plays in binding the properties of a visual object that varies on the features of color and size in rats. Rats with PPC lesions or control surgery were exposed to three blocks of 20 trials administered over a 1-week period, with each block containing ten-one feature and ten-two feature trials. The target object consisted of one color object (e.g. black and white and one size object (e.g. short and tall. Of the ten one feature trials, five of the trials were tailored specifically for size discrimination and five for color discrimination. In the two-feature condition, the animal was required to locate the targeted object among four objects with two objects differing in size and two objects differing in color. The results showed a significant decrease in learning the task for the PPC lesioned rats compared to controls, especially for the two-feature condition. Based on a subsequent error analysis for color and size, the results showed a significant increase in illusory conjunction errors for the PPC lesioned rats relative to controls for color and relative to color discrimination, suggesting that the PPC may support feature binding as it relates to color. There was an increase in illusory conjunctions errors for both the PPC lesioned and control animals for size, but this appeared to be due to a difficulty with size discrimination.

  5. The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

    Science.gov (United States)

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman’s capsule expressed podocyte markers, and cells on Bowman’s capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman’s capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman’s capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman’s capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans. PMID:24408873

  6. Podocyte and Parietal Epithelial Cell Interactions in Health and Disease.

    Science.gov (United States)

    Al Hussain, Turki; Al Mana, Hadeel; Hussein, Maged H; Akhtar, Mohammed

    2017-01-01

    The glomerulus has 3 resident cells namely mesangial cells that produce the mesangial matrix, endothelial cells that line the glomerular capillaries, and podocytes that cover the outer surface of the glomerular basement membrane. Parietal epithelial cells (PrECs), which line the Bowman's capsule are not part of the glomerular tuft but may have an important role in the normal function of the glomerulus. A significant progress has been made in recent years regarding our understanding of the role and function of these cells in normal kidney and in kidneys with various types of glomerulopathy. In crescentic glomerulonephritis necrotizing injury of the glomerular tuft results in activation and leakage of fibrinogen which provides the trigger for excessive proliferation of PrECs giving rise to glomerular crescents. In cases of collapsing glomerulopathy, podocyte injury causes collapse of the glomerular capillaries and activation and proliferation of PrECs, which accumulate within the urinary space in the form of pseudocrescents. Many of the noninflammatory glomerular lesions such as focal segmental glomerulosclerosis and global glomerulosclerosis also result from podocyte injury which causes variable loss of podocytes. In these cases podocyte injury leads to activation of PrECs that extend on to the glomerular tuft where they cause segmental and/or global sclerosis by producing excess matrix, resulting in obliteration of the capillary lumina. In diabetic nephropathy, in addition to increased matrix production in the mesangium and glomerular basement membranes, increased loss of podocytes is an important determinant of long-term prognosis. Contrary to prior belief there is no convincing evidence for an active podocyte proliferation in any of the above mentioned glomerulopathies.

  7. Post-traumatic stress disorder: a right temporal lobe syndrome?

    Science.gov (United States)

    Engdahl, B.; Leuthold, A. C.; Tan, H.-R. M.; Lewis, S. M.; Winskowski, A. M.; Dikel, T. N.; Georgopoulos, A. P.

    2010-12-01

    In a recent paper (Georgopoulos et al 2010 J. Neural Eng. 7 016011) we reported on the power of the magnetoencephalography (MEG)-based synchronous neural interactions (SNI) test to differentiate post-traumatic stress disorder (PTSD) subjects from healthy control subjects and to classify them with a high degree of accuracy. Here we show that the main differences in cortical communication circuitry between these two groups lie in the miscommunication of temporal and parietal and/or parieto-occipital right hemispheric areas with other brain areas. This lateralized temporal-posterior pattern of miscommunication was very similar but was attenuated in patients with PTSD in remission. These findings are consistent with observations (Penfield 1958 Proc. Natl Acad. Sci. USA 44 51-66, Penfield and Perot 1963 Brain 86 595-696, Gloor 1990 Brain 113 1673-94, Banceaud et al 1994 Brain 117 71-90, Fried 1997 J. Neuropsychiatry Clin. Neurosci. 9 420-8) that electrical stimulation of the temporal cortex in awake human subjects, mostly in the right hemisphere, can elicit the re-enactment and re-living of past experiences. Based on these facts, we attribute our findings to the re-experiencing component of PTSD and hypothesize that it reflects an involuntarily persistent activation of interacting neural networks involved in experiential consolidation.

  8. Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

    Science.gov (United States)

    Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

    2011-10-01

    Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible participants reliably experienced greater state dissociation and exhibited lower frontal-parietal phase synchrony in the alpha2 frequency band during hypnosis than low suggestible participants. These findings suggest that highly suggestible individuals exhibit a disruption of the frontal-parietal network that is only observable following a hypnotic induction. Copyright © 2011 Society for Psychophysiological Research.

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

    Directory of Open Access Journals (Sweden)

    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. Haptically Guided Grasping. fMRI Shows Right-Hemisphere Parietal Stimulus Encoding, and Bilateral Dorso-Ventral Parietal Gradients of Object- and Action-Related Processing during Grasp Execution.

    Science.gov (United States)

    Marangon, Mattia; Kubiak, Agnieszka; Króliczak, Gregory

    2015-01-01

    The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI) to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation, and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC) of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks). None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial) parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

  11. Epilepsy classification and additional definitions in occipital lobe epilepsy.

    Science.gov (United States)

    Yilmaz, Kutluhan; Karatoprak, Elif Yüksel

    2015-09-01

    To evaluate epileptic children with occipital lobe epilepsy (OLE) in the light of the characteristics of Panayiotopoulos syndrome and late-onset occipital lobe epilepsy of Gastaut (OLE-G). Patients were categorized into six groups: primary OLE with autonomic symptoms (Panayiotopoulos syndrome), primary OLE with visual symptoms (OLE-G), secondary OLE with autonomic symptoms (P-type sOLE), secondary OLE with visual symptoms (G-type sOLE), and non-categorized primary OLE and non-categorized secondary OLE according to characteristic ictal symptoms of both Panayiotopoulos syndrome and OLE-G, as well as aetiology (primary or secondary). Patients were compared with regards to seizure symptoms, aetiology, cranial imaging, EEG, treatment and outcome. Of 108 patients with OLE (6.4±3.9 years of age), 60 patients constituted primary groups (32 with Panayiotopoulos syndrome, 11 with OLE-G, and 17 with non-categorized primary OLE); the other 48 patients constituted secondary groups (eight with P-type sOLE, three with G-type sOLE, and 37 with non-categorized sOLE). Epileptiform activity was restricted to the occipital area in half of the patients. Generalized epileptiform activity was observed in three patients, including a patient with Panayiotopoulos syndrome (PS). Only one patient had refractory epilepsy in the primary groups while such patients made up 29% in the secondary groups. In OLE, typical autonomic or visual ictal symptoms of Panayiotopoulos syndrome and OLE-G do not necessarily indicate primary (i.e. genetic or idiopathic) aetiology. Moreover, primary OLE may not present with these symptoms. Since there are many patients with OLE who do not exhibit the characteristics of Panayiotopoulos syndrome or OLE-G, additional definitions and terminology appear to be necessary to differentiate between such patients in both clinical practice and studies.

  12. A new approach for improving diagnostic accuracy in Alzheimer's disease and frontal lobe dementia utilising the intrinsic properties of the SPET dataset

    Energy Technology Data Exchange (ETDEWEB)

    Pagani, Marco [Institute of Cognitive Sciences and Technology, CNR, Viale Marx 15, 00137, Rome (Italy); Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden); Kovalev, Vassili A. [Institute of Engineering Cybernetics, Belarus National Academy of Sciences, Minsk (Belarus); Max-Planck Institute of Cognitive Neuroscience, Leipzig (Germany); Lundqvist, Roger; Thurfjell, Lennart [Applied Medical Imaging, Uppsala (Sweden); Jacobsson, Hans [Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden); Department of Radiology, Karolinska Hospital, Stockholm (Sweden); Larsson, Stig A. [Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden)

    2003-11-01

    Alzheimer's disease (AD) and frontal lobe dementia (FLD) show characteristic patterns of regional cerebral blood flow (rCBF). However, these patterns may overlap with those observed in the aging brain in elderly normal individuals. The aim of this study was to develop a new method for better classification and recognition of AD and FLD cases as compared with normal controls. Forty-six patients with AD, 7 patients with FLD and 34 normal controls (CTR) were included in the study. rCBF was assessed by technetium-99m hexamethylpropylene amine oxime and a three-headed single-photon emission tomography (SPET) camera. A brain atlas was used to define volumes of interest (VOIs) corresponding to the brain lobes. In addition to conventional image processing methods, based on count density/voxel, the new approach also analysed other intrinsic properties of the data by means of gradient computation steps. Hereby, five factors were assessed and tested separately: the mean count density/voxel and its histogram, the mean gradient and its histogram, and the gradient angle co-occurrence matrix. A feature vector concatenating single features was also created and tested. Preliminary feature discrimination was performed using a two-sided t-test and a K-means clustering was then used to classify the image sets into categories. Finally, five-dimensional co-occurrence matrices combining the different intrinsic properties were computed for each VOI, and their ability to recognise the group to which each individual scan belonged was investigated. For correct classification of the AD-CTR groups, the gradient histogram in the parieto-temporal lobes was the most useful single feature (accuracy 91%). FLD and CTR were better classified by the count density/voxel histogram (frontal and occipital lobes) and by the mean gradient (frontal, temporal and parietal lobes, accuracy 98%). For AD and FLD the count density/voxel histogram in the frontal, parietal and occipital lobes classified the

  13. A new approach for improving diagnostic accuracy in Alzheimer's disease and frontal lobe dementia utilising the intrinsic properties of the SPET dataset

    International Nuclear Information System (INIS)

    Pagani, Marco; Kovalev, Vassili A.; Lundqvist, Roger; Thurfjell, Lennart; Jacobsson, Hans; Larsson, Stig A.

    2003-01-01

    Alzheimer's disease (AD) and frontal lobe dementia (FLD) show characteristic patterns of regional cerebral blood flow (rCBF). However, these patterns may overlap with those observed in the aging brain in elderly normal individuals. The aim of this study was to develop a new method for better classification and recognition of AD and FLD cases as compared with normal controls. Forty-six patients with AD, 7 patients with FLD and 34 normal controls (CTR) were included in the study. rCBF was assessed by technetium-99m hexamethylpropylene amine oxime and a three-headed single-photon emission tomography (SPET) camera. A brain atlas was used to define volumes of interest (VOIs) corresponding to the brain lobes. In addition to conventional image processing methods, based on count density/voxel, the new approach also analysed other intrinsic properties of the data by means of gradient computation steps. Hereby, five factors were assessed and tested separately: the mean count density/voxel and its histogram, the mean gradient and its histogram, and the gradient angle co-occurrence matrix. A feature vector concatenating single features was also created and tested. Preliminary feature discrimination was performed using a two-sided t-test and a K-means clustering was then used to classify the image sets into categories. Finally, five-dimensional co-occurrence matrices combining the different intrinsic properties were computed for each VOI, and their ability to recognise the group to which each individual scan belonged was investigated. For correct classification of the AD-CTR groups, the gradient histogram in the parieto-temporal lobes was the most useful single feature (accuracy 91%). FLD and CTR were better classified by the count density/voxel histogram (frontal and occipital lobes) and by the mean gradient (frontal, temporal and parietal lobes, accuracy 98%). For AD and FLD the count density/voxel histogram in the frontal, parietal and occipital lobes classified the groups

  14. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2014-01-01

    In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  15. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2014-03-01

    Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  16. Frontal Lobe Function in Chess Players

    Directory of Open Access Journals (Sweden)

    Vahid Nejati

    2012-05-01

    Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  17. Frontal lobe function in chess players.

    Science.gov (United States)

    Nejati, Majid; Nejati, Vahid

    2012-01-01

    Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST) data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players don't have any preference in any stage of Stroop test. Chess players don't have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  18. MR imaging in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Fobben, E.S.; Zimmerman, R.A.; Sperling, M.R.; Kohn, M.I.; Atlas, S.W.; Hackney, D.B.; Goldberg, H.I.; Bilaniuk, L.T.; Grossman, R.I.

    1988-01-01

    MR imaging examinations of 31 patients undergoing temporal lobe resection for refractory partial epilepsy were reviewed retrospectively for the presence of signal abnormalities as well as atrophy. High-signal abnormalities were present in only two of the described 31 patients (6.5%). Pathologically, these represented mesial temporal sclerosis and a hamartoma. Of the remaining 29 cases, 13 showed pathologically varying degrees of mesial temporal sclerosis and gliosis and 16 were pathologically normal. Atrophy, as determined by gross asymmetry, sulcal and temporal horn enlargement, and computer volume measurements, was observed in 23 of 31 patients, correlating with the clinically affected side in 20 and the contralateral side in three. In this series, in contrast to others reported, focal MR signal abnormalities were not detected in the vast majority of patients with mesial temporal sclerosis

  19. The right hemisphere's contribution to discourse processing: A study in temporal lobe epilepsy.

    Science.gov (United States)

    Lomlomdjian, Carolina; Múnera, Claudia P; Low, Daniel M; Terpiluk, Verónica; Solís, Patricia; Abusamra, Valeria; Kochen, Silvia

    2017-08-01

    Discourse skills - in which the right hemisphere has an important role - enables verbal communication by selecting contextually relevant information and integrating it coherently to infer the correct meaning. However, language research in epilepsy has focused on single word analysis related mainly to left hemisphere processing. The purpose of this study was to investigate discourse abilities in patients with right lateralized medial temporal lobe epilepsy (RTLE) by comparing their performance to that of patients with left temporal lobe epilepsy (LTLE). 74 pharmacoresistant temporal lobe epilepsy (TLE) patients were evaluated: 34 with RTLE and 40 with LTLE. Subjects underwent a battery of tests that measure comprehension and production of conversational and narrative discourse. Disease related variables and general neuropsychological data were evaluated. The RTLE group presented deficits in interictal conversational and narrative discourse, with a disintegrated speech, lack of categorization and misinterpretation of social meaning. LTLE group, on the other hand, showed a tendency to lower performance in logical-temporal sequencing. RTLE patients showed discourse deficits which have been described in right hemisphere damaged patients due to other etiologies. Medial and anterior temporal lobe structures appear to link semantic, world knowledge, and social cognition associated areas to construct a contextually related coherent meaning. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Custom-made different designs of pressure clips for the management of ear lobe keloids

    Directory of Open Access Journals (Sweden)

    Anshul Chugh

    2013-01-01

    Full Text Available Introduction : Keloids are frequent finding after physical trauma. Keloids of ear lobe are common complication of ear piercing, although its incidence remains unknown. The use of intrakeloid resection and a form pressure device to treat pinna keloids. The recommendation of this therapy is to maintain constant pressure and duration of pressure therapy was about 25 weeks. Clinical innovation : This article will present inexpensive custom made pressure clips of various designs. The dimensions of polymethylmethacrylate (PMMA plates in ear lobe clip presented by us though they esthetically not so good, but colored PMMA has been used to make it decorative and acceptable by most of the patients. This has been an encouraging experience to use the different designs. Discussion : Ear clip prosthesis has been developed for maintaining pressure on ear lobe keloids before and after surgical removal. The prosthesis includes an ear clip to which heat-polymerized acrylic resin is attached, which covers the keloid area. Pressure therapy is widely used to help in the early maturation of scar tissue and to prevent the recurrence of keloid. The preliminary report by Brent revealed that constant light pressure was an effective means of preventing post excision recurrence of ear lobe keloids using a decorative, spring-pressure earring.

  1. Cognitive deficits are associated with frontal and temporal lobe white matter lesions in middle-aged adults living in the community.

    Directory of Open Access Journals (Sweden)

    David Bunce

    Full Text Available BACKGROUND: The association between brain white matter lesions and cognitive impairment in old age is well established. However, little is known about this association in midlife. As this information will inform policy for early preventative healthcare initiatives, we investigated non-periventricular frontal, temporal, parietal and occipital lobe white matter hyperintensities (WMH in relation to cognitive function in 428 (232 women community-dwelling adults aged 44 to 48 years. RESULTS: Frontal white matter lesions were significantly associated with greater intraindividual RT variability in women, while temporal WMH were associated with face recognition deficits in men. Parietal and occipital lobe lesions were unrelated to cognitive performance. These findings did not differ when education and a range of health variables, including vascular risk factors, were taken into account. CONCLUSION: Gender differences in WMH-cognition associations are discussed, and we conclude that small vessel disease is present in midlife and has functional consequences which are generally not recognized. Preventative strategies should, therefore, begin early in life.

  2. The Oft-Neglected Role of Parietal EEG Asymmetry and Risk for Major Depressive Disorder

    Science.gov (United States)

    Stewart, Jennifer L.; Towers, David N.; Coan, James A.; Allen, John J.B.

    2010-01-01

    Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n = 143) and without (n = 163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity. PMID:20525011

  3. Craniopharyngioma in the temporal lobe: a case report

    International Nuclear Information System (INIS)

    Sohn, Chul-Ho; Baik, Seung-Kug; Kim, Sang-Pyo; Kim, Il-Man; Sevick, Robert J.

    2004-01-01

    Herein, we report on an unusual case of craniopharyngioma arising in the temporal lobe with no prior history of surgery and with no connection to the craniopharyngeal duct. MR images showed cystic tumor with a small solid portion. To the best of our knowledge, this is the first case of a craniopharyngioma occurring in the temporal lobe

  4. Craniopharyngioma in the temporal lobe: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Chul-Ho; Baik, Seung-Kug; Kim, Sang-Pyo; Kim, Il-Man; Sevick, Robert J. [University of Calgary, Calgary (Canada)

    2004-03-15

    Herein, we report on an unusual case of craniopharyngioma arising in the temporal lobe with no prior history of surgery and with no connection to the craniopharyngeal duct. MR images showed cystic tumor with a small solid portion. To the best of our knowledge, this is the first case of a craniopharyngioma occurring in the temporal lobe.

  5. Craniopharyngioma in the Temporal Lobe: A Case Report

    Science.gov (United States)

    Baik, Seung Kug; Kim, Sang-Pyo; Kim, Il-Man; Sevick, Robert J.

    2004-01-01

    Herein, we report on an unusual case of craniopharyngioma arising in the temporal lobe with no prior history of surgery and with no connection to the craniopharyngeal duct. MR images showed a cystic tumor with a small solid portion. To the best of our knowledge, this is the first case of a craniopharyngioma occurring in the temporal lobe. PMID:15064562

  6. A comparative perspective on the human temporal lobe

    NARCIS (Netherlands)

    Bryant, K.L.; Preuss, T.M.; Bruner, E.; Ogihara, N.; Tanabe, H.

    2018-01-01

    The temporal lobe is a morphological specialization of primates resulting from an expansion of higher-order visual cortex that is a hallmark of the primate brain. Among primates, humans possess a temporal lobe that has significantly expanded. Several uniquely human cognitive abilities, including

  7. Surgical anatomy of the pyramidal lobe and its significance in ...

    African Journals Online (AJOL)

    In diffuse thyroid diseases, the lobes were always pathologically involved and significantly longer. Conclusion. Since the pyramidal lobe is a normal component of the thyroid gland, of varying position and size, with pathological changes in benign and malignant diseases, it should always be examined during thyroid surgery ...

  8. Parietal neural prosthetic control of a computer cursor in a graphical-user-interface task

    Science.gov (United States)

    Revechkis, Boris; Aflalo, Tyson NS; Kellis, Spencer; Pouratian, Nader; Andersen, Richard A.

    2014-12-01

    Objective. To date, the majority of Brain-Machine Interfaces have been used to perform simple tasks with sequences of individual targets in otherwise blank environments. In this study we developed a more practical and clinically relevant task that approximated modern computers and graphical user interfaces (GUIs). This task could be problematic given the known sensitivity of areas typically used for BMIs to visual stimuli, eye movements, decision-making, and attentional control. Consequently, we sought to assess the effect of a complex, GUI-like task on the quality of neural decoding. Approach. A male rhesus macaque monkey was implanted with two 96-channel electrode arrays in area 5d of the superior parietal lobule. The animal was trained to perform a GUI-like ‘Face in a Crowd’ task on a computer screen that required selecting one cued, icon-like, face image from a group of alternatives (the ‘Crowd’) using a neurally controlled cursor. We assessed whether the crowd affected decodes of intended cursor movements by comparing it to a ‘Crowd Off’ condition in which only the matching target appeared without alternatives. We also examined if training a neural decoder with the Crowd On rather than Off had any effect on subsequent decode quality. Main results. Despite the additional demands of working with the Crowd On, the animal was able to robustly perform the task under Brain Control. The presence of the crowd did not itself affect decode quality. Training the decoder with the Crowd On relative to Off had no negative influence on subsequent decoding performance. Additionally, the subject was able to gaze around freely without influencing cursor position. Significance. Our results demonstrate that area 5d recordings can be used for decoding in a complex, GUI-like task with free gaze. Thus, this area is a promising source of signals for neural prosthetics that utilize computing devices with GUI interfaces, e.g. personal computers, mobile devices, and tablet

  9. Parietal neural prosthetic control of a computer cursor in a graphical-user-interface task.

    Science.gov (United States)

    Revechkis, Boris; Aflalo, Tyson N S; Kellis, Spencer; Pouratian, Nader; Andersen, Richard A

    2014-12-01

    To date, the majority of Brain-Machine Interfaces have been used to perform simple tasks with sequences of individual targets in otherwise blank environments. In this study we developed a more practical and clinically relevant task that approximated modern computers and graphical user interfaces (GUIs). This task could be problematic given the known sensitivity of areas typically used for BMIs to visual stimuli, eye movements, decision-making, and attentional control. Consequently, we sought to assess the effect of a complex, GUI-like task on the quality of neural decoding. A male rhesus macaque monkey was implanted with two 96-channel electrode arrays in area 5d of the superior parietal lobule. The animal was trained to perform a GUI-like 'Face in a Crowd' task on a computer screen that required selecting one cued, icon-like, face image from a group of alternatives (the 'Crowd') using a neurally controlled cursor. We assessed whether the crowd affected decodes of intended cursor movements by comparing it to a 'Crowd Off' condition in which only the matching target appeared without alternatives. We also examined if training a neural decoder with the Crowd On rather than Off had any effect on subsequent decode quality. Despite the additional demands of working with the Crowd On, the animal was able to robustly perform the task under Brain Control. The presence of the crowd did not itself affect decode quality. Training the decoder with the Crowd On relative to Off had no negative influence on subsequent decoding performance. Additionally, the subject was able to gaze around freely without influencing cursor position. Our results demonstrate that area 5d recordings can be used for decoding in a complex, GUI-like task with free gaze. Thus, this area is a promising source of signals for neural prosthetics that utilize computing devices with GUI interfaces, e.g. personal computers, mobile devices, and tablet computers.

  10. The contribution of the human posterior parietal cortex to episodic memory

    OpenAIRE

    Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

    2017-01-01

    The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, poten...

  11. The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

    OpenAIRE

    O'Connor, Akira R.; Han, Sanghoon; Dobbins, Ian G.

    2010-01-01

    Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success patter...

  12. Supplementary CT temporal lobe cuts confer no worthwhile benefit

    Energy Technology Data Exchange (ETDEWEB)

    Straiton, J A; Macpherson, P; Teasdale, E M [Institute of Neurological Sciences, Glasgow (UK). Dept. of Neuroradiology

    1991-02-01

    The value of angled temporal lobe cuts as a supplement to conventional head computed tomography (CT) has been assessed by comparing the diagnostic yield of standard axial and specific temporal lobe images (TLCT) in 62 patients with temporal lobe epilepsy and 87 with Alzheimer-type senile dementia. Fewer than one patient in six had structural abnormality in the temporal lobe most readily demonstrated by axial CT. Five patients with epilepsy and ten with dementia had changes demonstrated only by TLCT, reported on by one or other of a pair of observers. However such changes were of dubious clinical relevance, or arose as a result of artefact. In one patient with epilepsy and underlying neoplasm, axial CT was positive and TLCT false-negative. The routine addition of temporal lobe cuts to a conventional axial examination confers no added benefit to justify the prolonged examination time and increased radiation dose to the lens of the eye. (orig.).

  13. Supplementary CT temporal lobe cuts confer no worthwhile benefit

    International Nuclear Information System (INIS)

    Straiton, J.A.; Macpherson, P.; Teasdale, E.M.

    1991-01-01

    The value of angled temporal lobe cuts as a supplement to conventional head computed tomography (CT) has been assessed by comparing the diagnostic yield of standard axial and specific temporal lobe images (TLCT) in 62 patients with temporal lobe epilepsy and 87 with Alzheimer-type senile dementia. Fewer than one patient in six had structural abnormality in the temporal lobe most readily demonstrated by axial CT. Five patients with epilepsy and ten with dementia had changes demonstrated only by TLCT, reported on by one or other of a pair of observers. However such changes were of dubious clinical relevance, or arose as a result of artefact. In one patient with epilepsy and underlying neoplasm, axial CT was positive and TLCT false-negative. The routine addition of temporal lobe cuts to a conventional axial examination confers no added benefit to justify the prolonged examination time and increased radiation dose to the lens of the eye. (orig.)

  14. An Efficient Approach for Identifying Stable Lobes with Discretization Method

    Directory of Open Access Journals (Sweden)

    Baohai Wu

    2013-01-01

    Full Text Available This paper presents a new approach for quick identification of chatter stability lobes with discretization method. Firstly, three different kinds of stability regions are defined: absolute stable region, valid region, and invalid region. Secondly, while identifying the chatter stability lobes, three different regions within the chatter stability lobes are identified with relatively large time intervals. Thirdly, stability boundary within the valid regions is finely calculated to get exact chatter stability lobes. The proposed method only needs to test a small portion of spindle speed and cutting depth set; about 89% computation time is savedcompared with full discretization method. It spends only about10 minutes to get exact chatter stability lobes. Since, based on discretization method, the proposed method can be used for different immersion cutting including low immersion cutting process, the proposed method can be directly implemented in the workshop to promote machining parameters selection efficiency.

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

    Science.gov (United States)

    Bettencourt, Katherine C; Xu, Yaoda

    2016-01-01

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

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

    Science.gov (United States)

    Bettencourt, Katherine C.; Xu, Yaoda

    2015-01-01

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

  17. Occipital Lobe Gray Matter Volume in Male Patients with Chronic Schizophrenia: A Quantitative MRI Study

    Science.gov (United States)

    Onitsuka, Toshiaki; McCarley, Robert W.; Kuroki, Noriomi; Dickey, Chandlee C.; Kubicki, Marek; Demeo, Susan S.; Frumin, Melissa; Kikinis, Ron; Jolesz, Ferenc A.; Shenton, Martha E.

    2008-01-01

    Schizophrenia is characterized by deficits in cognition as well as visual perception. There have, however, been few magnetic resonance imaging (MRI) studies of the occipital lobe as an anatomically defined region of interest in schizophrenia. To examine whether or not patients with chronic schizophrenia show occipital lobe volume abnormalities, we measured gray matter volumes for both the primary visual area (PVA) and the visual association areas (VAA) using MRI based neuroanatomical landmarks and three-dimensional information. PVA and VAA gray matter volumes were measured using high-spatial resolution MRI in 25 male patients diagnosed with chronic schizophrenia and in 28 male normal controls. Chronic schizophrenia patients showed reduced bilateral VAA gray matter volume (11%), compared with normal controls, whereas patients showed no group difference in PVA gray matter volume. These results suggest that reduced bilateral VAA may be a neurobiological substrate of some of the deficits observed in early visual processing in schizophrenia. PMID:17350226

  18. Visual perception and memory systems: from cortex to medial temporal lobe.

    Science.gov (United States)

    Khan, Zafar U; Martín-Montañez, Elisa; Baxter, Mark G

    2011-05-01

    Visual perception and memory are the most important components of vision processing in the brain. It was thought that the perceptual aspect of a visual stimulus occurs in visual cortical areas and that this serves as the substrate for the formation of visual memory in a distinct part of the brain called the medial temporal lobe. However, current evidence indicates that there is no functional separation of areas. Entire visual cortical pathways and connecting medial temporal lobe are important for both perception and visual memory. Though some aspects of this view are debated, evidence from both sides will be explored here. In this review, we will discuss the anatomical and functional architecture of the entire system and the implications of these structures in visual perception and memory.

  19. Controlling factors of turf-banked solifluction lobe evolution in the Turtmann glacier forefield (Switzerland)

    Science.gov (United States)

    Draebing, Daniel; Eichel, Jana

    2016-04-01

    Soil structure and moisture, thermal conditions and vegetation control solifluction movement, however, the spatial distribution of controlling factors and resultant spatial variability of movement are poorly understood. We use a (1) geomorphological and vegetation mapping of solifluction lobe properties, (2) temperature loggers to quantify thermal conditions, (3) 2D Electrical Resistivity Tomography (ERT), Puerkhauer drilling and TDR measurements to evaluate material properties as well as (4) 3D Time-Lapse ERT to quantify spatial variability of material properties. Our results are used to (5) evaluate the influence of potential controlling factors on solifluction movement. Investigations took place on three turf-banked lobes (TBL) located at proximal and distal slopes of Little Ice Age and 1920s lateral moraines in the Turtmann glacier forefield, Swiss Alps. (1) Vegetation is spatially differentiated at TBLs. The treads are mostly covered by the ecosystem engineer Dryas octopetala, while other dwarf shrubs, shrubs and pioneer species were found at the high lobe risers (0.8-1.8 m). In contrast, less vegetated ridge-like features at the upper part of the treads are colonized by frost-tolerant species. Large blocks are located at the lobe fronts, probably impeding the lobe movement. (2) Temperature loggers show a lack of ground cooling due to snow isolation at the vegetated lower tread between 2014 and 2015. Thus, significant ground cooling in winter is reduced to the wind-exposed upper parts (ridges). (3) TBL material consists of sandy silt, thus, lobe material is much finer than subjacent moraine till and indicates former colluviation. As a consequence, 2D ERT demonstrates low-resistant areas until depths equal to riser height, thus, the finer TBL body is higher saturated than the coarser surrounding parent slope and more susceptible to gelifluction. On the contrary, risers show high resistivities indicating dry conditions which are supported by TDR results

  20. Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame

    Directory of Open Access Journals (Sweden)

    Jakub Limanowski

    2018-03-01

    Full Text Available Spatially and temporally congruent visuotactile stimulation of a fake hand together with one’s real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants’ index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

  1. Activity in human visual and parietal cortex reveals object-based attention in working memory.

    Science.gov (United States)

    Peters, Benjamin; Kaiser, Jochen; Rahm, Benjamin; Bledowski, Christoph

    2015-02-25

    Visual attention enables observers to select behaviorally relevant information based on spatial locations, features, or objects. Attentional selection is not limited to physically present visual information, but can also operate on internal representations maintained in working memory (WM) in service of higher-order cognition. However, only little is known about whether attention to WM contents follows the same principles as attention to sensory stimuli. To address this question, we investigated in humans whether the typically observed effects of object-based attention in perception are also evident for object-based attentional selection of internal object representations in WM. In full accordance with effects in visual perception, the key behavioral and neuronal characteristics of object-based attention were observed in WM. Specifically, we found that reaction times were shorter when shifting attention to memory positions located on the currently attended object compared with equidistant positions on a different object. Furthermore, functional magnetic resonance imaging and multivariate pattern analysis of visuotopic activity in visual (areas V1-V4) and parietal cortex revealed that directing attention to one position of an object held in WM also enhanced brain activation for other positions on the same object, suggesting that attentional selection in WM activates the entire object. This study demonstrated that all characteristic features of object-based attention are present in WM and thus follows the same principles as in perception. Copyright © 2015 the authors 0270-6474/15/353360-10$15.00/0.

  2. Enhancing creative cognition with a rapid right-parietal neurofeedback procedure.

    Science.gov (United States)

    Agnoli, Sergio; Zanon, Marco; Mastria, Serena; Avenanti, Alessio; Corazza, Giovanni Emanuele

    2018-02-14

    The present article describes an innovative neurofeedback training (NFT) procedure aimed at increasing creative cognition through the enhancement of specific brain activities previously associated with divergent thinking. We designed and tested two NFT protocols based on training alpha and beta EEG oscillations selectively measured over the right parietal region. A total of 80 participants were involved, 40 in the alpha NFT protocol and 40 in the beta NFT protocol. The NFT loop was closed on a video stream that would advance only when oscillation power exceeded a normalized threshold. The total duration of the protocol was two hours in a single day, hence its classification as rapid. Changes in ideational fluency and originality, measured with a divergent thinking task, were compared between participants receiving real video feedback and participants receiving sham feedback. We controlled for individual differences in creative achievement level. Results showed that the protocols were effective at enhancing alpha and beta activities in the targeted area. Differences between the two protocols emerged in their effectiveness at promoting divergent thinking. While no significant changes in originality resulted from the rapid alpha NFT, increases in both originality and fluency emerged as a consequence of the rapid beta NFT. These results were particularly evident in participants starting with a low creative achievement level. Possible interpretations and future directions are proposed and discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition

    Science.gov (United States)

    Daitch, Amy L.; Foster, Brett L.; Schrouff, Jessica; Rangarajan, Vinitha; Kaşikçi, Itır; Gattas, Sandra; Parvizi, Josef

    2016-01-01

    Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain. PMID:27821758

  4. 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

  5. Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame.

    Science.gov (United States)

    Limanowski, Jakub; Blankenburg, Felix

    2018-01-01

    Spatially and temporally congruent visuotactile stimulation of a fake hand together with one's real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants' index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

  6. 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.

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

    Science.gov (United States)

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

    2014-08-01

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

  8. Multitasking in the frontal lobes: An exploration of the effects of stress on cognition

    OpenAIRE

    McKernan, Laura

    2009-01-01

    Frontal lobe research has fractionated many of the higher-level processes associated with this area of the brain into specific aspects of executive functions. The current study furthers this investigation into the complex behaviour of multitasking and the modern impact of stress on these processes. A student sample of 41 participants (18 male, 23 female), were recruited and randomly assigned to either stressed or non-stressed groups. The experimental manipulation of stress was induced via a v...

  9. The Importance of Lateral Connections in the Parietal Cortex for Generating Motor Plans.

    Directory of Open Access Journals (Sweden)

    Derrik E Asher

    Full Text Available Substantial evidence has highlighted the significant role of associative brain areas, such as the posterior parietal cortex (PPC in transforming multimodal sensory information into motor plans. However, little is known about how different sensory information, which can have different delays or be absent, combines to produce a motor plan, such as executing a reaching movement. To address these issues, we constructed four biologically plausible network architectures to simulate PPC: 1 feedforward from sensory input to the PPC to a motor output area, 2 feedforward with the addition of an efference copy from the motor area, 3 feedforward with the addition of lateral or recurrent connectivity across PPC neurons, and 4 feedforward plus efference copy, and lateral connections. Using an evolutionary strategy, the connectivity of these network architectures was evolved to execute visually guided movements, where the target stimulus provided visual input for the entirety of each trial. The models were then tested on a memory guided motor task, where the visual target disappeared after a short duration. Sensory input to the neural networks had sensory delays consistent with results from monkey studies. We found that lateral connections within the PPC resulted in smoother movements and were necessary for accurate movements in the absence of visual input. The addition of lateral connections resulted in velocity profiles consistent with those observed in human and non-human primate visually guided studies of reaching, and allowed for smooth, rapid, and accurate movements under all conditions. In contrast, Feedforward or Feedback architectures were insufficient to overcome these challenges. Our results suggest that intrinsic lateral connections are critical for executing accurate, smooth motor plans.

  10. High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

    Science.gov (United States)

    Lobier, Muriel; Palva, J Matias; Palva, Satu

    2018-01-15

    Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. 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.

  12. Seizure Control and Memory Impairment Are Related to Disrupted Brain Functional Integration in Temporal Lobe Epilepsy.

    Science.gov (United States)

    Park, Chang-Hyun; Choi, Yun Seo; Jung, A-Reum; Chung, Hwa-Kyoung; Kim, Hyeon Jin; Yoo, Jeong Hyun; Lee, Hyang Woon

    2017-01-01

    Brain functional integration can be disrupted in patients with temporal lobe epilepsy (TLE), but the clinical relevance of this disruption is not completely understood. The authors hypothesized that disrupted functional integration over brain regions remote from, as well as adjacent to, the seizure focus could be related to clinical severity in terms of seizure control and memory impairment. Using resting-state functional MRI data acquired from 48 TLE patients and 45 healthy controls, the authors mapped functional brain networks and assessed changes in a network parameter of brain functional integration, efficiency, to examine the distribution of disrupted functional integration within and between brain regions. The authors assessed whether the extent of altered efficiency was influenced by seizure control status and whether the degree of altered efficiency was associated with the severity of memory impairment. Alterations in the efficiency were observed primarily near the subcortical region ipsilateral to the seizure focus in TLE patients. The extent of regional involvement was greater in patients with poor seizure control: it reached the frontal, temporal, occipital, and insular cortices in TLE patients with poor seizure control, whereas it was limited to the limbic and parietal cortices in TLE patients with good seizure control. Furthermore, TLE patients with poor seizure control experienced more severe memory impairment, and this was associated with lower efficiency in the brain regions with altered efficiency. These findings indicate that the distribution of disrupted brain functional integration is clinically relevant, as it is associated with seizure control status and comorbid memory impairment.

  13. Clinical and pathological study on 10 cases of cerebral lobe hemorrhage related with cerebral amyloid angiopathy

    Directory of Open Access Journals (Sweden)

    Xiao-qi LI

    2015-07-01

    Full Text Available Objective To summarize the clinical data and pathological features of 10 cases of cerebral lobar hemorrhage related with cerebral amyloid angiopathy (CAA diagnosed pathologically, thereby to improve the knowledge and diagnosis of the disease. Methods The clinical data of 10 cases of cerebral lobar hemorrhage related with CAA, collected in the General Hospital of Shenyang Command from 1983 up to now, were retrospectively analyzed, and the clinical and neuropathological features of these cases were summarized. Results Of the 10 patients, 2 suffered from single lobar hemorrhage and 8 multiple lobar hemorrhage, all of them were confirmed pathologically to have ruptured into the subarachnoid space. Pathological examination revealed microaneurysm in 2 cases, "double barrel" change in 4 cases, multiple arteriolar clusters in 5 cases, obliterative onion-liked intima change in 4 cases, and fibrinoid necrosis of vessel wall in 7 cases. In addition, neurofibrillary tangles were found in 8 cases, and senile plaque was observed in 5 cases. Conclusions Cerebral lobar hemorrhage related with CAA is mainly located in the parietal, temporal and occipital lobes, readily breaking into the subarachnoid space, and it is often multiple and recurrent. The CAA associated microvasculopathy was found frequently in the autopsy sample of CAA related cerebral lobar hemorrhage, and it may contribute to the pathogenesis of cerebral hemorrhage. DOI: 10.11855/j.issn.0577-7402.2015.07.04

  14. Clinical-physiologic correlates of Alzheimer's disease and frontal lobe dementia

    International Nuclear Information System (INIS)

    Jagust, W.J.; Reed, B.R.; Seab, J.P.; Kramer, J.H.; Budinger, T.F.

    1989-01-01

    Thirty patients with degenerative dementia underwent clinical evaluation, neuropsychological testing, and single photon emission computed tomography (SPECT) with the blood flow tracer [ 123 I]-N-isopropyl-p-iodoamphetamine. Five of these patients were clinically and psychologically different from the others, demonstrating predominant behavioral disturbances with relative preservation of memory function. These five patients, who were felt to have a frontal lobe dementia (FLD), showed SPECT perfusion patterns which differed from the remaining 25 patients, who were diagnosed as having Alzheimer's disease (AD), and from 16 healthy control subjects. The FLD patients showed diminished perfusion in orbitofrontal, dorsolateral frontal, and temporal cortex relative to controls, while the AD patients showed lower perfusion in temporal and parietal cortex than controls. The FLD patients also showed hypoperfusion in both frontal cortical regions relative to AD patients. The pattern of performance on neuropsychological testing paralleled these differences in regional perfusion. These results suggest that clinical evaluation and physiological imaging may enable the differentiation of groups of degenerative dementia patients during life

  15. 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

  16. Abnormality of cerebral cortical glucose metabolism in temporal lobe epilepsy with cognitive function impairment

    International Nuclear Information System (INIS)

    Bang-Hung Yang; Tsung-Szu Yeh; Tung-Ping Su; Jyh-Cheng Chen; Ren-Shyan Liu

    2004-01-01

    Objective: People with epilepsy commonly report having problems with their memory. Many indicate that memory difficulties significantly hinder their functioning at work, in school, and at home. Besides, some studies have reported that memory performance as a prognostic factor is of most value in patients with risk of refractory epilepsy and when used in a multidisciplinary setting. However, the cerebral cortical areas involving memory impairment in epilepsy is still unknown. The purpose of this study was to access changes of cerebral glucose metabolism of epilepsy patients using [F-18] fluorodeoxyglucose positron emission tomography (FDG PET). Method: Nine temporal lobe epilepsy patients were studied. Each patient was confirmed with lesions in right mesial temporal lobe by MRI, PET and EEG. Serial cognition function tests were performed. Regional cerebral glucose metabolism (rCMRglc) was measured by PET at 45 minutes after injection of 370 MBq of FDG. Parametric images were generated by grand mean scaling each scan to 50. The images were then transformed into standard stereotactic space. Statistical parametric mapping (SPM2) was applied to find the correlations between verbal memory, figure memory, perception intelligent quotation (PIQ) and rCMRglc in epilepsy patients. The changes of rCMRglc were significant if corrected p value was less than 0.05. Results: There was no significant relationship between figure memory score and verbal memory score. FDG-PET scan showed changes of rCMRglc positive related with verbal memory score in precentral gyms of right frontal lobe (Brodmann area 4, corrected p < 0.001, voxel size 240) and cingulated gyms of right limbic lobe (Brodmann area 32, corrected p=0.002, voxel size 143). No negative relationship was demonstrable between verbal memory and rCMRglc in this study. Besides, significanfiy positive correlation between figure memory was shown in cuneus of right occipital lobe (Brodmann area 18, corrected p < 0.001, voxel size

  17. Effect of pharmacological interventions on the fronto-cingulo-parietal cognitive control network in psychiatric disorders: a transdiagnostic systematic review of fMRI studies

    Directory of Open Access Journals (Sweden)

    Therese eVan Amelsvoort

    2016-05-01

    Full Text Available Executive function deficits such as working memory, decision-making, and attention problems are a common feature of several psychiatric disorders for which no satisfactory treatment exists. Here, we transdiagnostically investigate the effects of pharmacological interventions (other than methylphenidate on the fronto-cingulo-parietal cognitive control network, in order to identify functional brain markers for future pro-cognitive pharmacological interventions. 29 manuscripts investigated the effect of pharmacological treatment on executive function-related brain correlates in psychotic disorders (n=11, depression (n=4, bipolar disorder (n=4, ADHD (n=4, OCD (n=2, smoking dependence (n=2, alcohol dependence (n=1 and pathological gambling (n=1. In terms of impact on the fronto-cingulo-parietal networks, the preliminary evidence for catechol-o-methyl-transferase inhibitors, nicotinic receptor agonists and atomoxetine suggested was relatively consistent, the data for atypical antipsychotics and anticonvulsants moderate, and interpretation of the data for antidepressants was hampered by the employed study designs. Increased activity in task-relevant areas and decreased activity in task-irrelevant areas were the most common transdiagnostic effects of pharmacological treatment. These markers showed good positive and moderate negative predictive value. It is concluded that fronto-cingulo-parietal activity changes can serve as a marker for future pro-cognitive interventions. Future recommendations include the use of randomized double-blind designs and selective cholinergic and glutamatergic compounds.

  18. Functional Clustering of the Human Inferior Parietal Lobule by Whole-Brain Connectivity Mapping of Resting-State Functional Magnetic Resonance Imaging Signals

    Science.gov (United States)

    Li, Chiang-Shan R.

    2014-01-01

    Abstract The human inferior parietal lobule (IPL) comprised the lateral bank of the intraparietal sulcus, angular gyrus, and supramarginal gyrus, defined on the basis of anatomical landmarks and cytoarchitectural organization of neurons. However, it is not clear as to whether the three areas represent functional subregions within the IPL. For instance, imaging studies frequently identified clusters of activities that cut across areal boundaries. Here, we used resting-state functional magnetic resonance imaging (fMRI) data to examine how individual voxels within the IPL are best clustered according to their connectivity to the whole brain. The results identified a best estimate of seven clusters that are hierarchically arranged as the anterior, middle, and posterior subregions. The anterior, middle, and posterior IPL are each significantly connected to the somatomotor areas, superior/middle/inferior frontal gyri, and regions of the default mode network. This functional segregation is supported by recent cytoarchitechtonics and tractography studies. IPL showed hemispheric differences in connectivity that accord with a predominantly left parietal role in tool use and language processing and a right parietal role in spatial attention and mathematical cognition. The functional clusters may also provide a more parsimonious and perhaps even accurate account of regional activations of the IPL during a variety of cognitive challenges, as reported in earlier fMRI studies. PMID:24308753

  19. Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterial-spin-labeling based MRI

    International Nuclear Information System (INIS)

    Shen Lianfang; Zhang Zhiqiang; Lu Guangming; Yuan Cuiping; Wang Zhengge; Wang Haoxue; Huang Wei; Wei Fangyuan; Chen Guanghui; Tan Qifu

    2012-01-01

    Objective: To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy (mTLE) by using arterial-spin-labeling (ASL) based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status. Methods: Twenty-five patients with left-sided and 23 with right-sided mTLE were enrolled, and 30 healthy volunteers were recruited. The cerebral blood flow (CBF) of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner. The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis. The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal side in matched region in mTLE group. Results: Compared with the volunteers, the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal, the frontal and parietal regions relating to the default-mode network and more serious in lesion side. The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration (r=-0.51, P<0.01). The asymmetric index of CBF as-0.01 has a 76.0% (19/25) sensitivity and a 78.3% (18/23) specificity to distinguish the lesion side. Conclusions: The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE. The ASL technique is a useful tool for lateralizing the unilateral mTLE. (authors)

  20. Atypical handedness in mesial temporal lobe epilepsy.

    Science.gov (United States)

    Doležalová, Irena; Schachter, Steven; Chrastina, Jan; Hemza, Jan; Hermanová, Markéta; Rektor, Ivan; Pažourková, Marta; Brázdil, Milan

    2017-07-01

    The main aim of our study was to investigate the handedness of patients with mesial temporal lobe epilepsy (MTLE). We also sought to identify clinical variables that correlated with left-handedness in this population. Handedness (laterality quotient) was assessed in 73 consecutive patients with MTLE associated with unilateral hippocampal sclerosis (HS) using the Edinburgh Handedness Inventory. Associations between right- and left-handedness and clinical variables were investigated. We found that 54 (74.0%) patients were right-handed, and 19 (26%) patients were left-handed. There were 15 (36.6%) left-handed patients with left-sided seizure onset compared to 4 (12.5%) left-handed patients with right-sided seizure onset (p=0.030). Among patients with left-sided MTLE, age at epilepsy onset was significantly correlated with handedness (8years of age [median; min-max 0.5-17] in left-handers versus 15years of age [median; min-max 3-30] in right-handers (p<0.001). Left-sided MTLE is associated with atypical handedness, especially when seizure onset occurs during an active period of brain development, suggesting a bi-hemispheric neuroplastic process for establishing motor dominance in patients with early-onset left-sided MTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Episodic reinstatement in the medial temporal lobe.

    Science.gov (United States)

    Staresina, Bernhard P; Henson, Richard N A; Kriegeskorte, Nikolaus; Alink, Arjen

    2012-12-12

    The essence of episodic memory is our ability to reexperience past events in great detail, even in the absence of external stimulus cues. Does the phenomenological reinstatement of past experiences go along with reinstating unique neural representations in the brain? And if so, how is this accomplished by the medial temporal lobe (MTL), a brain region intimately linked to episodic memory? Computational models suggest that such reinstatement (also termed "pattern completion") in cortical regions is mediated by the hippocampus, a key region of the MTL. Although recent functional magnetic resonance imaging studies demonstrated reinstatement of coarse item properties like stimulus category or task context across different brain regions, it has not yet been shown whether reinstatement can be observed at the level of individual, discrete events-arguably the defining feature of episodic memory-nor whether MTL structures like the hippocampus support this "true episodic" reinstatement. Here we show that neural activity patterns for unique word-scene combinations encountered during encoding are reinstated in human parahippocampal cortex (PhC) during retrieval. Critically, this reinstatement occurs when word-scene combinations are successfully recollected (even though the original scene is not visually presented) and does not encompass other stimulus domains (such as word-color associations). Finally, the degree of PhC reinstatement across retrieval events correlated with hippocampal activity, consistent with a role of the hippocampus in coordinating pattern completion in cortical regions.

  2. Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Tae Kwan; Kim, Dong Wook; Park, Ha Kyoung; Jung, Soo Jin [Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-12-15

    We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

  3. Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

    African Journals Online (AJOL)

    in abnormal development of the deep layers of the cerebral cortex and production ... focal, unilateral, bilateral or asymmetrical, and have been described in all areas of .... did not recognise food in the mouth, no tongue movement was observed.

  4. Differential effects of parietal and frontal inactivations on reaction times distributions in a visual search task

    Directory of Open Access Journals (Sweden)

    Claire eWardak

    2012-06-01

    Full Text Available The posterior parietal cortex participates to numerous cognitive functions, from perceptual to attentional and decisional processes. However, the same functions have also been attributed to the frontal cortex. We previously conducted a series of reversible inactivations of the lateral intraparietal area (LIP and of the frontal eye field (FEF in the monkey which showed impairments in covert visual search performance, characterized mainly by an increase in the mean reaction time (RT necessary to detect a contralesional target. Only subtle differences were observed between the inactivation effects in both areas. In particular, the magnitude of the deficit was dependant of search task difficulty for LIP, but not for FEF.In the present study, we re-examine these data in order to try to dissociate the specific involvement of these two regions, by considering the entire RT distribution instead of mean RT. We use the LATER model to help us interpret the effects of the inactivations with regard to information accumulation rate and decision processes. We show that: 1 different search strategies can be used by monkeys to perform visual search, either by processing the visual scene in parallel, or by combining parallel and serial processes; 2 LIP and FEF inactivations have very different effects on the RT distributions in the two monkeys. Although our results are not conclusive with regards to the exact functional mechanisms affected by the inactivations, the effects we observe on RT distributions could be accounted by an involvement of LIP in saliency representation or decision-making, and an involvement of FEF in attentional shifts and perception. Finally, we observe that the use of the LATER model is limited in the context of a visual search as it cannot fit all the behavioural strategies encountered. We propose that the diversity in search strategies observed in our monkeys also exists in individual human subjects and should be considered in future

  5. Neural representation of hand kinematics during prehension in posterior parietal cortex of the macaque monkey.

    Science.gov (United States)

    Chen, Jessie; Reitzen, Shari D; Kohlenstein, Jane B; Gardner, Esther P

    2009-12-01

    Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal-how and when he used the hand-appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand.

  6. Turbulent measurements in the lobe mixer of a turbofan engine. Turbofan engine lobe mixer nagare no ranryu keisoku

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Makoto; Ogawa, Yuji; Arakawa, Chuichi; Tagori, Tetsuo [Ishikawajima-Harima Heavy Industries, Co., Ltd., Tokyo, (Japan) Nippon Steel Corp., Tokyo, (Japan) The Univ. of Tokyo, Tokyo, (Japan). Faculty of Engineering The Univ. of Tsukuba, Tsukuba, (Japan)

    1990-01-25

    In order to examine the flow generated by the lobe mixer of a turbofan engine precisely, after measuring a three dimensional turbulent flow by a hot-wire anemometer, the mixing process of a bypass flow and a core flow with cross-sectional vortexes, and factors generating the vortex were clarified experimentally using the scale model of an exhaust duct with the lobe mixer. As a result, the mixing process was strongly affected by a lobe tip figure and a lobe figure near a center-body, and affected by the minimum gap between the lobe and center-body. The subsequent mixing process was scarcely affected by the ratio of a core flow velocity to a bypass flow one, although strongly affected by flow conditions on a lobe surface. Since the lobe mixer promoted the mixing around a center axis shifting a fast core flow outwards, it was unfavorable to mixing, however, it was expected to be useful for reducing engine jet noise. 3 refs., 7 figs.

  7. Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps.

    Science.gov (United States)

    Sood, Mariam R; Sereno, Martin I

    2016-08-01

    Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I. Hum Brain Mapp 37:2784-2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  8. SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

    International Nuclear Information System (INIS)

    Won, Kyoung Sook; Zeon, Seok Kil

    2004-01-01

    This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity

  9. SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

    Energy Technology Data Exchange (ETDEWEB)

    Won, Kyoung Sook; Zeon, Seok Kil [Keimyung University Dongsan Medical Center, Daegu (Korea, Republic of)

    2004-07-01

    This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity.

  10. SPECT image analysis using statistical parametric mapping in patients with temporal lobe epilepsy associated with hippocampal sclerosis

    International Nuclear Information System (INIS)

    Shiraki, Junko

    2004-01-01

    The author examined interictal 123 I-IMP SPECT images using statistical parametric mapping (SPM) in 19 temporal lobe epilepsy patients who revealed hippocampal sclerosis with MRI. Decreased regional cerebral blood flow (rCBF) were shown for eight patients in the medial temporal lobe, six patients in the lateral temporal lobe and five patients in the both medial and lateral temporal lobe. These patients were classified into two types; medial type and lateral type, the former decreased rCBF only in medial and the latter decreased rCBF in the other temporal area. Correlation of rCBF and clinical parameters in the lateral type, age at seizure onset was significantly older (p=0.0098, t-test) than those of patients in the medial type. SPM analysis for interictal SPECT of temporal lobe epilepsy clarified location of decreased rCBF and find correlations with clinical characteristics. In addition, SPM analysis of SPECT was useful to understand pathophysiology of the epilepsy. (author)

  11. Temporal lobe and hypothalmic-pituitary dysfunctions after radiotherapy for nasopharyngeal carcinoma: a distinct clinical syndrome

    International Nuclear Information System (INIS)

    Woo, E.; Lam, K.; Yu, Y.L.; Ma, J.; Wang, C.; Yeung, R.T.T.

    1988-01-01

    Eleven patients with combined neurological and endocrine complications after external radiotherapy for nasopharyngeal carcinoma are described. Memory disturbance, complex partial seizures and hypodense areas in one or both temporal lobes on CT were typical features. Endocrinologically, hypopituitarism was the prominent manifestation. This constellation of clinical features in a patient with previous radiotherapy to the nasopharynx characterises radiation injury to the inferomedial aspects of the temporal lobes and the hypothalamic-pituitary axis. While parenchymal brain lesions may mimic metastases or glioma on CT, associated endocrine disturbance would betray the correct diagnosis. The importance of recognising hypo-pituitarism which may be clinically asymptomatic and which is amenable to therapy is emphasised, as is the need for a proper fractionation of radiation dose to minimise the incidence of these disabling complications. (author)

  12. [Two cases of mesial temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe without "dual pathology"].

    Science.gov (United States)

    Morioka, T; Nishio, S; Hisada, K; Muraishi, M; Ishibashi, H; Mamiya, K; Ohfu, M; Fukui, M

    1998-05-01

    Two cases of intractable temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe were reported. Although preoperative magnetic resonance imaging (MRI) failed to reveal hippocampal atrophy with T2 hyperintensity, electrocorticographic (ECoG) recording with chronic invasive subdural electrodes indicated the mesial temporal lobe to be an ictal onset zone. After anterior temporal lobectomy involving the lesion and hippocampectomy, the patients became seizure-free. Hippocampal sclerosis, namely "dual pathology", was not noted on histological examination. Careful ECoG recording with chronic subdural electrodes is mandatory even when the preoperative MRI does not demonstrate the radiological hippocampal sclerosis.

  13. Feasibility of the Medial Temporal lobe Atrophy index (MTAi and derived methods for measuring atrophy of the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Francisco eConejo Bayón

    2014-11-01

    Full Text Available Introduction: the Medial Temporal-lobe Atrophy index (MTAi, 2D-Medial Temporal Atrophy (2D-MTA, yearly rate of MTA (yrRMTA and yearly rate of relative MTA (yrRMTA are simple protocols for measuring the relative extent of atrophy in the MTL in relation to the global brain atrophy. Albeit preliminary studies showed interest of these methods in the diagnosis of AD, FTLD and correlation with cognitive impairment in PD, formal feasibility and validity studies remained pending. As a first step, we aimed to assess the feasibility. Mainly, we aimed to assess the reproducibility of measuring the areas needed to compute these indices. We also aimed to assess the efforts needed to start using these methods correctly. Methods: a series of 290 1.5T-MRI studies from 230 subjects ranging 65-85 years old who had been studied for cognitive impairment were used in this study. Six inexperienced tracers (IT plus one experienced tracer (ET traced the three areas needed to compute the indices. Finally, tracers underwent a short survey on their experience learning to compute the MTAi and experience of usage, including items relative to training time needed to understand and apply the MTAi, time to perform a study after training and overall satisfaction. Results: learning to trace the areas needed to compute the MTAi and derived methods is quick and easy. Results indicate very good intrarater ICC for the MTAi, good intrarater ICC for the 2D-MTA, yrMTA and yrRMTA and also good interrater ICC for the MTAi, 2D-MTA, yrMTA and yrRMTA.Conclusion: our data support that MTAi and derived methods (2D-MTA, yrMTA and yrRTMA have good to very good intrarater and interrater reproducibility and may be easily implemented in clinical practice even if new users have no experience tracing the area of regions of interest.

  14. Pediatric frontal lobe epilepsy : white matter abnormalities and cognitive impairment

    NARCIS (Netherlands)

    Braakman, H.M.H.; Vaessen, M.J.; Jansen, J.F.A.; Debeij-van Hall, M.H.J.A.; Louw, de A.; Hofman, P.A.M.; Vles, J.S.H.; Aldenkamp, A.P.; Backes, W.H.

    2014-01-01

    Objectives: Cognitive impairment is frequent in children with frontal lobe epilepsy (FLE). Its etiology remains unknown. With diffusion tensor imaging, we have studied cerebral white matter properties and associations with cognitive functioning in children with FLE and healthy controls.

  15. Genetics Home Reference: autosomal dominant nocturnal frontal lobe epilepsy

    Science.gov (United States)

    ... with ADNFLE have experienced psychiatric disorders (such as schizophrenia), behavioral problems, or intellectual disability. It is unclear ... Epilepsy Society Citizens United for Research in Epilepsy (CURE) GeneReviews (1 link) Autosomal Dominant Nocturnal Frontal Lobe ...

  16. Magnetic resonance tomography (MRT) for lesions of the temporal lobes

    International Nuclear Information System (INIS)

    Schoerner, W.; Felix, R.; Meencke, H.J.; Freie Univ. Berlin; Freie Univ. Berlin

    1985-01-01

    A comparative study between magnetic resonance tomography (MRT) and CT was carried out in 16 patients with temporal lobe epilepsy. The MRT studies were performed on a 0.35 T Magnetom with T.1 modes in a coronal plane. MRT proved to the superior to CT. CT demonstrated a discrete temporal lobe lesion in three patients and MRT in four patients. In addition, unilateral atrophy of the temporal lobe was demonstrated by MRT in six cases; these could not be diagnosed by CT. The lack of artifacts near the skull base, the possibility of producing coronal sections and the excellent tissue differential of MRT provide the basis for improved diagnosis of lesions in the temporal lobes. (orig.) [de

  17. Cognitive impairments in patients with intractable temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Mahgol Tavakoli

    2011-01-01

    Conclusions: These findings indicated that WMS-III and WAIS-R can differentiate patients with refractory temporal lobe epilepsy from normal subjects. However, the obtained cognitive profile could not differentiate between the right and the left TLE.

  18. Spike voltage topography in temporal lobe epilepsy.

    Science.gov (United States)

    Asadi-Pooya, Ali A; Asadollahi, Marjan; Shimamoto, Shoichi; Lorenzo, Matthew; Sperling, Michael R

    2016-07-15

    We investigated the voltage topography of interictal spikes in patients with temporal lobe epilepsy (TLE) to see whether topography was related to etiology for TLE. Adults with TLE, who had epilepsy surgery for drug-resistant seizures from 2011 until 2014 at Jefferson Comprehensive Epilepsy Center were selected. Two groups of patients were studied: patients with mesial temporal sclerosis (MTS) on MRI and those with other MRI findings. The voltage topography maps of the interictal spikes at the peak were created using BESA software. We classified the interictal spikes as polar, basal, lateral, or others. Thirty-four patients were studied, from which the characteristics of 340 spikes were investigated. The most common type of spike orientation was others (186 spikes; 54.7%), followed by lateral (146; 42.9%), polar (5; 1.5%), and basal (3; 0.9%). Characteristics of the voltage topography maps of the spikes between the two groups of patients were somewhat different. Five spikes in patients with MTS had polar orientation, but none of the spikes in patients with other MRI findings had polar orientation (odds ratio=6.98, 95% confidence interval=0.38 to 127.38; p=0.07). Scalp topographic mapping of interictal spikes has the potential to offer different information than visual inspection alone. The present results do not allow an immediate clinical application of our findings; however, detecting a polar spike in a patient with TLE may increase the possibility of mesial temporal sclerosis as the underlying etiology. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. SPITZER OBSERVATIONS OF HOTSPOTS IN RADIO LOBES

    International Nuclear Information System (INIS)

    Werner, Michael W.; Murphy, David W.; Livingston, John H.; Gorjian, Varoujan; Jones, Dayton L.; Meier, David L.; Lawrence, Charles R.

    2012-01-01

    We have carried out a systematic search with Spitzer Warm Mission and archival data for infrared emission from the hotspots in radio lobes that have been described by Hardcastle et al. These hotspots have been detected with both radio and X-ray observations, but an observation at an intermediate frequency in the infrared can be critical to distinguish between competing models for particle acceleration and radiation processes in these objects. Between the archival and warm mission data, we report detections of 18 hotspots; the archival data generally include detections at all four IRAC bands, the Warm Mission data only at 3.6 μm. Using a theoretical formalism adopted from Godfrey et al., we fit both archival and warm mission spectral energy distributions (SEDs)—including radio, X-ray, and optical data from Hardcastle as well as the Spitzer data—with a synchrotron self-Compton (SSC) model, in which the X-rays are produced by Compton scattering of the radio frequency photons by the energetic electrons which radiate them. With one exception, an SSC model requires that the magnetic field be less or much less than the equipartition value which minimizes total energy and has comparable amounts of energy in the magnetic field and in the energetic particles. This conclusion agrees with those of comparable recent studies of hotspots, and with the analysis presented by Hardcastle et al. We also show that the infrared data rule out the simplest synchrotron-only models for the SEDs. We briefly discuss the implications of these results and of alternate interpretations of the data.

  20. Surgery in temporal lobe epilepsy patients without cranial MRI lateralization.

    Science.gov (United States)

    Gomceli, Y B; Erdem, A; Bilir, E; Kutlu, G; Kurt, S; Erden, E; Karatas, A; Erbas, C; Serdaroglu, A

    2006-03-01

    High resolution MRI is very important in the evaluations of patients with intractable temporal lobe epilepsy in preoperative investigations. Morphologic abnormalities on cranial MRI usually indicate the epileptogenic focus. Intractable TLE patients who have normal cranial MRI or bilateral hippocampal atrophy may have a chance for surgery if a certain epileptogenic focus is determined. We evaluated the patients who were monitorized in Gazi University Medical Faculty Epilepsy Center from October 1997 to April 2004. Seventy three patients, who had a temporal epileptogenic focus, underwent anterior temporal lobectomy at Ankara University Medical Faculty Department of Neurosurgery. Twelve of them (16, 4%), did not have any localizing structural lesion on cranial MRI. Of the 12 patients examined 6 had normal findings and 6 had bilateral hippocampal atrophy. Of these 12 patients, 6 (50%) were women and 6 (50%) were men. The ages of patients ranged from 7 to 37 (mean: 24.5). Preoperatively long-term scalp video-EEG monitoring, cranial MRI, neuropsychological tests, and Wada test were applied in all patients. Five patients, whose investigations resulted in conflicting data, underwent invasive monitoring by the use of subdural strips. The seizure outcome of patients were classified according to Engel with postsurgical follow-up ranging from 11 to 52 (median: 35.7) months. Nine patients (75%) were classified into Engel's Class I and the other 3 patients (25%) were placed into Engel's Class II. One patient who was classified into Engel's Class II had additional psychiatric problems. The other patient had two different epileptogenic foci independent from each other in her ictal EEG. One of them localized in the right anterior temporal area, the other was in the right frontal lobe. She was classified in Engel's Class II and had no seizure originating from temporal epileptic focus, but few seizures originating from the frontal region continued after the surgery. In conclusion

  1. Mapping thalamocortical network pathology in temporal lobe epilepsy.

    Science.gov (United States)

    Bernhardt, Boris C; Bernasconi, Neda; Kim, Hosung; Bernasconi, Andrea

    2012-01-10

    Although experimental work has provided evidence that the thalamus is a crucial relay structure in temporal lobe epilepsy (TLE), the relation of the thalamus to neocortical pathology remains unclear. To assess thalamocortical network pathology in TLE, we mapped pointwise patterns of thalamic atrophy and statistically related them to neocortical thinning. We studied cross-sectionally 36 patients with drug-resistant TLE and 19 age- and sex-matched healthy control subjects using high-resolution MRI. To localize thalamic pathology, we converted manual labels into surface meshes using the spherical harmonic description and calculated local deformations relative to a template. In addition, we measured cortical thickness by means of the constrained Laplacian anatomic segmentation using proximity algorithm. Compared with control subjects, patients with TLE showed ipsilateral thalamic atrophy that was located along the medial surface, encompassing anterior, medial, and posterior divisions. Unbiased analysis correlating the degree of medial thalamic atrophy with cortical thickness measurements mapped bilateral frontocentral, lateral temporal, and mesiotemporal cortices. These areas overlapped with those of cortical thinning found when patients were compared with control subjects. Thalamic atrophy intensified with a longer duration of epilepsy and was more severe in patients with a history of febrile convulsions. The degree and distribution of thalamic pathology relates to the topography and extent of neocortical atrophy, lending support to the concept that the thalamus is an important hub in the pathologic network of TLE.

  2. Rat intermediate lobe in culture: a histological and biochemical characterization.

    Science.gov (United States)

    Chronwall, B M; Bishop, J F; Gehlert, D R

    1988-01-01

    The histology, immunohistochemistry, peptide synthesis and secretion as well as proliferation rate of rat intermediate lobe (IL) were studied in primary cultures. The cultures contained two populations of cells: melanotrophs either organized in free floating lobules or in lobules which attached to the dishes and formed a monolayer. Both populations retained their in vivo morphology: polyhedral cells with smooth, ovoid nuclei and a large number of cytoplasmic secretory coated vesicles, a well developed Golgi apparatus, abundant mitochondria and extensive areas of rough endoplasmic reticulum. The melanotrophs stained with varying intensity for alpha-MSH and in situ hybridization showed the presence of pro-opiomelanocortin (POMC) mRNA. 35S-methionine incorporation combined with 2-D gel electrophoresis demonstrated POMC peptide synthesis and radioimmunoassay confirmed its secretion into the medium. 3H-thymidine uptake in the attached melanotrophs was considerably higher than that in the free-floating melanotrophs, demonstrating the dependency of proliferation rate on the cytoarchitecture of the explant. The retention of melanotroph morphology, biosynthetic and proliferative capacity in vitro affords a valid model system for studying POMC gene expression.

  3. Patterns of verbal learning and memory in children with intractable temporal lobe or frontal lobe epilepsy.

    Science.gov (United States)

    Fuentes, Amanda; Smith, Mary Lou

    2015-12-01

    The objective of this study was to provide a better understanding of the verbal learning and memory (VLM) patterns that might differentiate children with frontal lobe epilepsy (FLE) from children with temporal lobe epilepsy (TLE) and to examine the impact of variables thought to influence outcomes (seizure laterality, age at seizure onset, age at assessment, epilepsy duration, number of antiepileptic drugs). Retrospective analyses were carried out for children with intractable unilateral TLE (n=100) and FLE (n=27) who completed standardized measures of VLM entailing lists of single words or lists of word pairs. Mean intelligent quotients and VLM scores on single words fell within the average range for both groups, whereas scores fell within the low average to borderline range on word pairs. No significant overall differences in VLM were found between the group with TLE and the group with FLE. Older age at assessment and older age at seizure onset were generally associated with better VLM in both groups but were related to better performance in a number of indices in the group with TLE and only fewer intrusions in the group with FLE. The VLM profiles of children with TLE and FLE are generally similar. Older age at assessment and older age at seizure onset have a favorable impact on both groups but are related to better encoding, retrieval, and monitoring processes for the group with TLE and improved memory monitoring (i.e., as indicated by fewer intrusions) in the group with FLE. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. A comparison of occipital and temporal lobe epilepsies.

    Science.gov (United States)

    Appel, S; Sharan, A D; Tracy, J I; Evans, J; Sperling, M R

    2015-10-01

    Differentiating between occipital lobe epilepsy (OLE) and temporal lobe epilepsy (TLE) is often challenging. This retrospective case-control study compares OLE to TLE and explores markers that suggest the diagnosis of OLE. We queried the Jefferson Epilepsy Center surgery database for patients who underwent a resection that involved the occipital lobe. For each patient with OLE, three sequential case-control patients with TLE were matched. Demographic characteristics, symptoms, electrophysiological findings, imaging findings, and surgical outcome were compared. Nineteen patients with OLE and 57 patients with TLE were included in the study. Visual symptoms were unique to patients with OLE (8/19) and were not reported by patients with TLE (P Occipital interictal spikes (IIS) were found only in one-third of the patients with OLE (6/19) and in no patients with TLE (P lobe were found in five of 19 patients with OLE vs one of 57 patients with TLE (P = 0.003). IIS involved more than one lobe of the brain in most patients with OLE (11/19) but only in nine of 57 the TLE group. (P = 0.0003) Multilobar resection was needed in most patients with OLE (15/19), typically including the temporal lobe, but in only one of the patients with TLE (P Occipital lobe epilepsy is difficult to identify and may masquerade as temporal lobe epilepsy. Visual symptoms and occipital findings in the EEG suggest the diagnosis of OLE, but absence of these features, does not exclude the diagnosis. When posterior temporal EEG findings or multilobar involvement occurs, the diagnosis of OLE should be considered. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Accessory hepatic lobe simulating a left hemidiaphragmatic tumor

    International Nuclear Information System (INIS)

    Kuroiwa, Toshiro; Hirata, Hitoshi; Iwashita, Akinori; Yasumori, Kotaro; Mogami, Hiroshi; Teraoka, Hiroaki

    1984-01-01

    A 72-year-old woman with a 20-year history of neuralgia was confirmed at surgery to have a tumor in the left hemidiaphragmatic region which was connected with the left lobe of the liver. Reassessment of radiological diagnosis after surgery revealed that hepatobiliary scintigraphy and computed tomography using left anterior oblique scanning are useful in differentiating the accessory hepatic lobe of the liver from a tumor and in confirming the diagnosis, respectively. (Namekawa, K.)

  6. Transcranial direct current stimulation over the parietal cortex alters bias in item and source memory tasks.

    Science.gov (United States)

    Pergolizzi, Denise; Chua, Elizabeth F

    2016-10-01

    Neuroimaging data have shown that activity in the lateral posterior parietal cortex (PPC) correlates with item recognition and source recollection, but there is considerable debate about its specific contributions. Performance on both item and source memory tasks were compared between participants who were given bilateral transcranial direct current stimulation (tDCS) over the parietal cortex to those given prefrontal or sham tDCS. The parietal tDCS group, but not the prefrontal group, showed decreased false recognition, and less bias in item and source discrimination tasks compared to sham stimulation. These results are consistent with a causal role of the PPC in item and source memory retrieval, likely based on attentional and decision-making biases. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Modulation of fronto-parietal connections during the rubber hand illusion

    DEFF Research Database (Denmark)

    Karabanov, Anke Ninija; Ritterband-Rosenbaum, Anina; Christensen, Mark Schram

    2017-01-01

    Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate...... and during three RHI conditions: a) agency and ownership, b) agency but no ownership and c) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which...... cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest...

  8. 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......-handed subjects to test if this procedure could modulate M1 excitability and PPC–M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased...... 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...

  9. Versive seizures in occipital lobe epilepsy: lateralizing value and pathophysiology.

    Science.gov (United States)

    Usui, Naotaka; Mihara, Tadahiro; Baba, Koichi; Matsuda, Kazumi; Tottori, Takayasu; Umeoka, Shuichi; Kondo, Akihiko; Nakamura, Fumihiro; Terada, Kiyohito; Usui, Keiko; Inoue, Yushi

    2011-11-01

    To clarify the value of versive seizures in lateralizing and localizing the epileptogenic zone in patients with occipital lobe epilepsy, we studied 13 occipital lobe epilepsy patients with at least one versive seizure recorded during preoperative noninvasive video-EEG monitoring, who underwent occipital lobe resection, and were followed postoperatively for more than 2 years with Engel's class I outcome. The videotaped versive seizures were analyzed to compare the direction of version and the side of surgical resection in each patient. Moreover, we examined other motor symptoms (partial somatomotor manifestations such as tonic and/or clonic movements of face and/or limbs, automatisms, and eyelid blinking) associated with version. Forty-nine versive seizures were analyzed. The direction of version was always contralateral to the side of resection except in one patient. Among accompanying motor symptoms, partial somatomotor manifestations were observed in only five patients. In conclusion, versive seizure is a reliable lateralizing sign indicating contralateral epileptogenic zone in occipital lobe epilepsy. Since versive seizures were accompanied by partial somatomotor manifestations in less than half of the patients, it is suggested that the mechanism of version in occipital lobe epilepsy is different from that in frontal lobe epilepsy. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Bicavitary effusion secondary to liver lobe torsion in a dog

    Directory of Open Access Journals (Sweden)

    Khan Z

    2016-04-01

    Full Text Available Zaheda Khan,1 Kathryn Gates,2 Stephen A Simpson,31Emergency and Critical Care, Animal Specialty and Emergency Center, Los Angeles, CA, 2Emergency and Critical Care, Advanced Critical Care, Emergency and Specialty Services, Culver City, CA 3Emergency and Critical Care, Southern California Veterinary Specialty Hospital, Irvine, CA, USA Abstract: We described the diagnosis and successful treatment of pleural and peritoneal effusion secondary to liver lobe torsion in a dog. A 12-year-old female spayed Borzoi dog was referred for heart failure. Emergency room thoracic and abdominal ultrasound showed a large volume of pleural effusion with mild peritoneal effusion and an abdominal mass. Pleural fluid analysis classified the effusion as exudative. A complete ultrasound revealed mild peritoneal effusion and decreased blood flow to the right liver lobe. Other causes of bicavitary effusion were ruled out based on blood work, ultrasound, echocardiogram, and computed tomography. The patient was taken to surgery and diagnosed with caudate liver lobe torsion and had a liver lobectomy. At the 2-week postoperative recheck, the patient was doing well and there was complete resolution of the pleural effusion. Liver lobe torsion is a rare occurrence in dogs and can be difficult to diagnose. Clinical signs are nonspecific for liver lobe torsion and patients may present in respiratory distress with significant pleural fluid accumulation. When assessing patients with pleural and peritoneal effusion, liver lobe torsion should be considered as a differential diagnosis.Keywords: pleural effusion, peritoneal effusion, hepatic torsion

  11. Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

    Directory of Open Access Journals (Sweden)

    Katrin Hanken

    2016-09-01

    Full Text Available Background: Fatigue in multiple sclerosis (MS patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1,5mA was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20min of a 40min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5mA over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. TDCS was delivered for 20min before patients performed a 20min lasting visual vigilance task.Results: Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in reaction time associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation.Conclusions: Anodal tDCS over the right parietal cortex can counteract the increase in reaction times during vigilance performance but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  12. Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Hanken, Katrin; Bosse, Mona; Möhrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

    2016-01-01

    Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1.5 mA) was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20 min of a 40-min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5 mA) over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. tDCS was delivered for 20 min before patients performed a 20-min lasting visual vigilance task. Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in RT associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation. Anodal tDCS over the right parietal cortex can counteract the increase in RTs during vigilance performance, but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  13. Semantic brain areas are involved in gesture comprehension: An electrical neuroimaging study.

    Science.gov (United States)

    Proverbio, Alice Mado; Gabaro, Veronica; Orlandi, Andrea; Zani, Alberto

    2015-08-01

    While the mechanism of sign language comprehension in deaf people has been widely investigated, little is known about the neural underpinnings of spontaneous gesture comprehension in healthy speakers. Bioelectrical responses to 800 pictures of actors showing common Italian gestures (e.g., emblems, deictic or iconic gestures) were recorded in 14 persons. Stimuli were selected from a wider corpus of 1122 gestures. Half of the pictures were preceded by an incongruent description. ERPs were recorded from 128 sites while participants decided whether the stimulus was congruent. Congruent pictures elicited a posterior P300 followed by late positivity, while incongruent gestures elicited an anterior N400 response. N400 generators were investigated with swLORETA reconstruction. Processing of congruent gestures activated face- and body-related visual areas (e.g., BA19, BA37, BA22), the left angular gyrus, mirror fronto/parietal areas. The incongruent-congruent contrast particularly stimulated linguistic and semantic brain areas, such as the left medial and the superior temporal lobe. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Optimized gamma synchronization enhances functional binding of fronto-parietal cortices in mathematically gifted adolescents during deductive reasoning

    Directory of Open Access Journals (Sweden)

    Li eZhang

    2014-06-01

    Full Text Available As enhanced fronto-parietal network has been suggested to support reasoning ability of math-gifted adolescents, the main goal of this EEG source analysis is to investigate the temporal binding of the gamma-band (30-60Hz synchronization between frontal and parietal cortices in adolescents with exceptional mathematical ability, including the functional connectivity of gamma neurocognitive network, the temporal dynamics of fronto-parietal network (phase-locking durations and network lability in time domain, and the self-organized criticality of synchronizing oscillation. Compared with the average-ability subjects, the math-gifted adolescents show a highly integrated fronto-parietal network due to distant gamma phase-locking oscillations, which is indicated by lower modularity of the global network topology, more connector bridges between the frontal and parietal cortices and less connector hubs in the sensorimotor cortex. The time-domain analysis finds that, while maintaining more stable phase dynamics of the fronto-parietal coupling, the math-gifted adolescents are characterized by more extensive fronto-parietal connection reconfiguration. The results from sample fitting in the power-law model further find that the phase-locking durations in the math-gifted brain abides by a wider interval of the power-law distribution. This phase-lock distribution mechanism could represent a relatively optimized pattern for the functional binding of frontal-parietal network, which underlies stable fronto-parietal connectivity and increases flexibility of timely network reconfiguration.

  15. The contribution of the human posterior parietal cortex to episodic memory.

    Science.gov (United States)

    Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

    2017-02-17

    The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

  16. Transcranial direct current stimulation of the posterior parietal cortex modulates arithmetic learning.

    Science.gov (United States)

    Grabner, Roland H; Rütsche, Bruno; Ruff, Christian C; Hauser, Tobias U

    2015-07-01

    The successful acquisition of arithmetic skills is an essential step in the development of mathematical competencies and has been associated with neural activity in the left posterior parietal cortex (PPC). It is unclear, however, whether this brain region plays a causal role in arithmetic skill acquisition and whether arithmetic learning can be modulated by means of non-invasive brain stimulation of this key region. In the present study we addressed these questions by applying transcranial direct current stimulation (tDCS) over the left PPC during a short-term training that simulates the typical path of arithmetic skill acquisition (specifically the transition from effortful procedural to memory-based problem-solving strategies). Sixty participants received either anodal, cathodal or sham tDCS while practising complex multiplication and subtraction problems. The stability of the stimulation-induced learning effects was assessed in a follow-up test 24 h after the training. Learning progress was modulated by tDCS. Cathodal tDCS (compared with sham) decreased learning rates during training and resulted in poorer performance which lasted over 24 h after stimulation. Anodal tDCS showed an operation-specific improvement for subtraction learning. Our findings extend previous studies by demonstrating that the left PPC is causally involved in arithmetic learning (and not only in arithmetic performance) and that even a short-term tDCS application can modulate the success of arithmetic knowledge acquisition. Moreover, our finding of operation-specific anodal stimulation effects suggests that the enhancing effects of tDCS on learning can selectively affect just one of several cognitive processes mediated by the stimulated area. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  17. Convergent functional architecture of the superior parietal lobule unraveled with multimodal neuroimaging approaches.

    Science.gov (United States)

    Wang, Jiaojian; Yang, Yong; Fan, Lingzhong; Xu, Jinping; Li, Changhai; Liu, Yong; Fox, Peter T; Eickhoff, Simon B; Yu, Chunshui; Jiang, Tianzi

    2015-01-01

    The superior parietal lobule (SPL) plays a pivotal role in many cognitive, perceptive, and motor-related processes. This implies that a mosaic of distinct functional and structural subregions may exist in this area. Recent studies have demonstrated that the ongoing spontaneous fluctuations in the brain at rest are highly structured and, like coactivation patterns, reflect the integration of cortical locations into long-distance networks. This suggests that the internal differentiation of a complex brain region may be revealed by interaction patterns that are reflected in different neuroimaging modalities. On the basis of this perspective, we aimed to identify a convergent functional organization of the SPL using multimodal neuroimaging approaches. The SPL was first parcellated based on its structural connections as well as on its resting-state connectivity and coactivation patterns. Then, post hoc functional characterizations and connectivity analyses were performed for each subregion. The three types of connectivity-based parcellations consistently identified five subregions in the SPL of each hemisphere. The two anterior subregions were found to be primarily involved in action processes and in visually guided visuomotor functions, whereas the three posterior subregions were primarily associated with visual perception, spatial cognition, reasoning, working memory, and attention. This parcellation scheme for the SPL was further supported by revealing distinct connectivity patterns for each subregion in all the used modalities. These results thus indicate a convergent functional architecture of the SPL that can be revealed based on different types of connectivity and is reflected by different functions and interactions. © 2014 Wiley Periodicals, Inc.

  18. Functional development of fronto-striato-parietal networks associated with time perception

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    Anna eSmith

    2011-11-01

    Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

  19. Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

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    Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

    2005-01-01

    Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

  20. Age-Dependent Mesial Temporal Lobe Lateralization in Language FMRI

    Science.gov (United States)

    Sepeta, Leigh N.; Berl, Madison M.; Wilke, Marko; You, Xiaozhen; Mehta, Meera; Xu, Benjamin; Inati, Sara; Dustin, Irene; Khan, Omar; Austermuehle, Alison; Theodore, William H.; Gaillard, William D.

    2015-01-01

    Objective FMRI activation of the mesial temporal lobe (MTL) may be important for epilepsy surgical planning. We examined MTL activation and lateralization during language fMRI in children and adults with focal epilepsy. Methods 142 controls and patients with left hemisphere focal epilepsy (Pediatric: epilepsy, n = 17, mean age = 9.9 ± 2.0; controls, n = 48; mean age = 9.1 ± 2.6; Adult: epilepsy, n = 20, mean age = 26.7 ± 5.8; controls, n = 57, mean age = 26.2 ± 7.5) underwent 3T fMRI using a language task (auditory description decision task). Image processing and analyses were conducted in SPM8; ROIs included MTL, Broca’s area, and Wernicke’s area. We assessed group and individual MTL activation, and examined degree of lateralization. Results Patients and controls (pediatric and adult) demonstrated group and individual MTL activation during language fMRI. MTL activation was left lateralized for adults but less so in children (p’s < 0.005). Patients did not differ from controls in either age group. Stronger left-lateralized MTL activation was related to older age (p = 0.02). Language lateralization (Broca’s and Wernicke’s) predicted 19% of the variance in MTL lateralization for adults (p = 0.001), but not children. Significance Language fMRI may be used to elicit group and individual MTL activation. The developmental difference in MTL lateralization and its association with language lateralization suggests a developmental shift in lateralization of MTL function, with increased left lateralization across the age span. This shift may help explain why children have better memory outcomes following resection compared to adults. PMID:26696589

  1. Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings

    International Nuclear Information System (INIS)

    Rodrigo, S.; Oppenheim, C.; Meder, J.F.; Chassoux, F.; Golestani, N.; Cointepas, Y.; Poupon, C.; Semah, F.; Mangin, J.F.; Le Bihan, D.

    2007-01-01

    In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas. (orig.)

  2. Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigo, S.; Oppenheim, C.; Meder, J.F. [Universite Paris-Descartes, Faculte de Medecine, Centre Hospitalier Sainte-Anne, Departement d' Imagerie Morphologique et Fonctionnelle, Paris (France); Chassoux, F. [Universite Paris-Descartes, Faculte de Medecine, Service de Neurochirurgie, Centre Hospitalier Sainte-Anne, Paris (France); Golestani, N.; Cointepas, Y.; Poupon, C.; Semah, F.; Mangin, J.F.; Le Bihan, D. [Service Hospitalier Frederic Joliot, CEA, Orsay (France)

    2007-07-15

    In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI s