A contribution of right and left brain hemispheres to pyramidal syndrome polymorphism and heterogeneity

The study aimed at investigation of clinical and neurophysiologic peculiarities of pyramidal syndrome in lateralized hemispheric lesion. Fifty-two patients with hemi-paresis caused by acute ischemic attack in the right (24 patients) and left (28 patients) brain hemispheres have been studied, using clinico-neurological analysis, transcranial magnetic stimulation, evoked abdominal reflexes, movement-related method of motor potential and somatosensory evoked potentials. in right hemispheric lesion, significant reduction of activating influences both on hemispheric and descending movement structures, pronounced damage of afferent flow from both body sides and excessive disorganizing activity in the left "relatively healthy" hemisphere were observed. Left hemispheric pathological process disturbs efferent control not only in the counter lateral body side, but in the ipsilateral one as well. The results obtained allow to discuss different neuroanatomical and neurophysiologic peculiarities of brain hemispheres, both in normal and pathological cases, as a factor, possibly determining polymorphism and heterogeneity of pyramidal syndrome in lateralized cerebral lesion.