The contributions of the right and left hemispheres of the brain to the polymorphism and heterogeneity of pyramidal syndrome

• Published in: Neuroscience and behavioral physiology Vol. 35; no. 3; pp. 229 - 234
• Main Authors: Ekusheva, E V, Vendrova, M I, Danilov, A B, Vein, A M
• Format: Journal Article
• Language: English
• Published: United States 01.03.2005
• Subjects: Adult; Brain Ischemia - complications; Brain Ischemia - physiopathology; Female; Functional Laterality; Humans; Interneurons - pathology; Male; Middle Aged; Motor Skills; Paresis - etiology; Paresis - physiopathology; Pyramidal Cells - physiopathology; Pyramidal Tracts - blood supply; Pyramidal Tracts - physiopathology; Severity of Illness Index; Statistics, Nonparametric; Stroke - complications; Stroke - physiopathology; Synaptic Transmission; Syndrome
• DOI: 10.1007/PL00022036
• ISSN: 0097-0549

This study was conducted to address the clinical and neurophysiological features of pyramidal syndrome in patients with lateralized hemispheric lesions. A total of 52 patients were studied, all with hemiparesis following acute cerebrovascular accidents of the ischemic type in the right (24 patients) or left (28 patients) hemispheres of the brain. Clinical neurological analysis was performed, along with transcranial magnetic stimulation, evoked abdominal reflexes, movement-associated motor potentials, and somatosensory evoked potentials. Lesions of the right hemisphere resulted in significant weakening of activatory influences at both the hemisphere level and on descending motor structures, with marked impairment of the afferent flow from both sides of the body and excessive disorganization of activity in the left, "presumptively healthy," side. Left-sided pathology impaired efferent control not only of the contralateral, but also of the ipsilateral side of the body. These data identify different neuroanatomical and neurophysiological features of the cerebral hemispheres not only in healthy people, but also in pathological conditions, this probably accounting for the polymorphism and heterogeneity of pyramidal syndrome in patients with lateralized cerebral lesions.