Modified activation of somatosensory cortical network in patients with right-hemisphere stroke.
TLDR
The results suggest that the human SI and SII cortices may be sequentially activated within one hemisphere, whereas SII ipsilateral to the stimulation may receive direct input from the periphery, at least when normal input from SI is interrupted.Abstract:
To study the effects of parietal lesions on activation of the human somatosensory cortical network, we measured somatosensory evoked fields to electric median nerve stimuli, using a whole-scalp 122-channel neuromagnetometer, from six patients with cortical right-hemisphere stroke and from seven healthy control subjects. In the control subjects, unilateral stimuli elicited responses which were satisfactorily accounted for by modelled sources in the contralateral primary (SI) and bilateral secondary (SII) somatosensory cortices. In all patients, stimulation of the right median nerve also activated the SI and SII cortices of the healthy left hemisphere. However, the activation pattern was altered, suggesting diminished interhemispheric inhibition via callosal connections after right-sided stroke. Responses to left median nerve stimuli showed large interindividual variability due to the different extents of the lesions. The strength of the 20-ms response, originating in the SI cortex, roughly reflected the severity of the tactile impairment. Right SII responses were absent in patients with abnormal right SI responses, whereas the left SII was active in all patients, regardless of the responsiveness of the right SI and/or SII. Our results suggest that the human SI and SII cortices may be sequentially activated within one hemisphere, whereas SII ipsilateral to the stimulation may receive direct input from the periphery, at least when normal input from SI is interrupted.read more
Citations
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References
More filters
Journal ArticleDOI
Magnetoencephalography—theory, instrumentation, and applications to noninvasive studies of the working human brain
TL;DR: The mathematical theory of the method is explained in detail, followed by a thorough description of MEG instrumentation, data analysis, and practical construction of multi-SQUID devices.
Journal ArticleDOI
Connexions of the somatic sensory cortex of the rhesus monkey. II. Contralateral cortical connexions.
E. G. Jones,T. P. S. Powell +1 more
TL;DR: The study on the somatic sensory cortex of the cat to the monkey is extended not only for the obvious reason of its closer affinity to man, but also because the larger size and clearer boundaries of the architectonic and functional subdivisions of the first somatics sensory area make these individual subdivisions more amenable to investigation.
Journal ArticleDOI
Human cortical potentials evoked by stimulation of the median nerve. II. Cytoarchitectonic areas generating long-latency activity.
TL;DR: The anatomic generators of human median nerve somatosensory evoked potentials were investigated in 54 patients by means of cortical-surface and transcortical recordings obtained during neurosurgery and suggest that the ipsilateral potentials are generated by transcallosal input from the contralateral hemisphere.
Journal ArticleDOI
Localization in somatic sensory and motor areas of human cerebral cortex as determined by direct recording of evoked potentials and electrical stimulation.
TL;DR: This study is unique in that cutaneous receptive fields related to specific cortical sites were defined by mechanical stimulation, as is done in animals, in contrast to electrical stimulation of peripheral nerves at fixed sites, as in scalp EP recordings.