[The effect of lesions of different parts of the optic thalamus on the nature of the bioelectrical activity of the human brain].

The EEG recordings of 41 patients with thalamic arteriovenous malformations (AVM) were studied by means of multivariate statistical analysis. In 16 patients the AVM were located in pulvinar, in 17 patients in the ventrolateral, in 4 patients in the medial, and in the remaining 4 patients in the anterior thalamic regions. Pathological EEG signs were visually classified and subjected to analysis of variance. The EEG signs were separated caused by the lesion localization. It was shown that the lesions in the posterior thalamus resulted in the alpha-rhythm suppression up to its total elimination. It was substituted for the bilateral local pathological activity in the posterior areas of the hemispheres. The diffuse beta-activity was observed. The ventrolateral and medial thalamic lesions led to the alpha-rhythm disorganization and its exaltation. The local slow waves were revealed in the sensorimotor cortical areas. The diffuse slow activity was observed as well as the signs of diencephalic irritation in the form of bilaterally synchronous bursts of activity in the alpha-theta range.