The corpus callosum in interhemispheric transmission and bilateral synchronization of paroxysmal activity

1969 ◽  
Vol 3 (2) ◽  
pp. 92-98
Author(s):  
Z. Sh. Kevanishvili ◽  
V. M. Mosidze ◽  
R. S. Rizhinashvili
Keyword(s):  
Corpus Callosum ◽  
Paroxysmal Activity ◽  
Interhemispheric Transmission

Interhemispheric Transmission of Visuomotor Information in Humans: fMRI Evidence

2002 ◽  
Vol 88 (2) ◽  
pp. 1051-1058 ◽  
Author(s):  
M. Tettamanti ◽  
E. Paulesu ◽  
P. Scifo ◽  
A. Maravita ◽  
F. Fazio ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Visual Information ◽  
Human Subjects ◽  
Conduction Time ◽  
Clear Cut ◽  
Cortical Areas ◽  
Poffenberger Paradigm ◽  
Interhemispheric Transmission ◽  
Hemispheric Activation ◽  
Normal Human

Normal human subjects underwent functional magnetic resonance imaging (fMRI) while performing a simple visual manual reaction-time (RT) task with lateralized brief stimuli, the so-called Poffenberger's paradigm. This paradigm was employed to measure interhemispheric transmission (IT) time by subtracting mean RT for the uncrossed hemifield-hand conditions, that is, those conditions not requiring an IT, from the crossed hemifield-hand conditions, that is, those conditions requiring an IT to relay visual information from the hemisphere of entry to the hemisphere subserving the response. The obtained difference is widely believed to reflect callosal conduction time, but so far there is no direct physiological evidence in humans. The aim of our experiment was twofold: first, to test the hypothesis that IT of visuomotor information requires the corpus callosum and to identify the cortical areas specifically activated during IT. Second, we sought to discover whether IT occurs mainly at premotor or perceptual stages of information processing. We found significant activations in a number of frontal, parietal, and temporal cortical areas and in the genu of the corpus callosum. These activations were present only in the crossed conditions and therefore were specifically related to IT. No selective activation was present in the uncrossed conditions. The location of the activated callosal and cortical areas suggests that IT occurs mainly, but not exclusively, at premotor level. These results provide clear cut evidence in favor of the hypothesis that the crossed-uncrossed difference in the Poffenberger paradigm depends on IT rather than on a differential hemispheric activation.

Sensory and Motor Interhemispheric Integration after Section of Different Portions of the Anterior Corpus Callosum in Nonepileptic Patients

Neurosurgery ◽  
2005 ◽  
Vol 57 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Stéphanie Caillé ◽  
Hannelore C. Sauerwein ◽  
Alessandra Schiavetto ◽  
Jean-Guy Villemure ◽  
Maryse Lassonde
Keyword(s):  
Corpus Callosum ◽  
Bimanual Coordination ◽  
Motor Coordination ◽  
Response Times ◽  
Motor Planning ◽  
The Body ◽  
Anterior Portion ◽  
Interhemispheric Transmission ◽  
Intraventricular Cyst ◽  
Anterior Body

Abstract OBJECTIVE: We evaluated somatosensory and motor interhemispheric integration in four patients who underwent transection of different portions of the anterior corpus callosum (CC) for removal of an intraventricular cyst. The study goal was to relate their performances to the topographical organization of the CC. METHODS: Experimental tasks included bimanual coordination, tactile cross-localization, and intermanual and interfield comparisons of somesthetic information. Response accuracy and response times were measured. In addition, interhemispheric transmission times were obtained in the somesthetic modality. RESULTS: Section of the middle portion of the genu caused a deficit in motor coordination, which was absent in patients with more posteriorly located lesions, whereas section of more rostral portions of the genu seemed to interfere with motor planning. The most posterior section in our sample, including the anterior portion of the body of the corpus, abolished interhemispheric transfer of simple somesthetic information (perception of touch) but not tactile discrimination (intermanual comparisons of shapes). We speculate that more complex somesthetic information is transferred through the caudal region of the body of the CC, which was spared in all patients. Thus, it seems that section of different portions of the anterior CC (genu and anterior body) produces specific deficits in interhemispheric integration in the motor and somesthetic modalities. These deficits are consistent with the anteroposterior topography of anterior callosal fibers. CONCLUSION: The specific disconnections deficits observed in this study may provide the surgeon with information regarding the consequences of anterior callosotomy and allow for remedial measures to be implemented if required.

Corpus callosum may be similar in children with ADHD and siblings of children with ADHD

2000 ◽  
Vol 42 (01) ◽  
pp. 8 ◽  
Author(s):  
S Overmeyer ◽  
A Simmons ◽  
J Santosh ◽  
C Andrew ◽  
S C R Williams ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Children With Adhd

Interhemispheric transfer evaluation in multiple sclerosis 1The authors would like to thank Claude-Alain Hauert and Christoph Michel for their assistance in the evaluation of motor tapping and Michel Habib for his suggestions and comments. This work was supported by a grant from the Swiss Society of Multiple Sclerosis.

2000 ◽  
Vol 59 (3) ◽  
pp. 150-158 ◽  
Author(s):  
Nadia Ortiz ◽  
Michael Reicherts ◽  
Alan J. Pegna ◽  
Encarni Garran ◽  
Michel Chofflon ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Corpus Callosum ◽  
Lexical Decision ◽  
Dichotic Listening ◽  
Neurological Impairment ◽  
Interhemispheric Transfer ◽  
Decision Task ◽  
Swiss Society ◽  
Listening Test ◽  
Relapsing Remitting

Patients suffering from Multiple Sclerosis (MS) have frequently been found to suffer from damage to callosal fibers. Investigations have shown that this damage is associated with signs of hemisphere disconnections. The aim of our study was to provide evidence for the first signs of interhemispheric dysfunction in a mildly disabled MS population. Therefore, we explored whether the Interhemispheric Transfer (IT) deficit is multi-modal and sought to differentiate two MS evolution forms, on the basis of an interhemispheric disconnection index. Twenty-two patients with relapsing-remitting form of MS (RRMS) and 14 chronic-progressive (CPMS) were compared with matched controls on four tasks: a tachistoscopic verbal and non-verbal decision task, a dichotic listening test, cross tactile finger localization and motor tapping. No overall impairment was seen. The dichotic listening and lexical decision tasks were the most sensitive to MS. In addition, CPMS patients' IT was more impaired and was related to the severity of neurological impairment. The different sizes of the callosal fibers, which determine their vulnerability, may explain the heterogeneity of transfer through the Corpus Callosum. Therefore, evaluation of IT may be of value as an index of evolution in MS.

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