[Rhythmic background activity of the thalamic neurons of patients with extrapyramidal movement disorders].

When applying the microelectrode method in neurosurgical clinic to differentiate white matter and thalamic nuclei the background activity of 123 thalamic neurons has been registered in 30 patients with motor extrapyramidal disorders. The recordings were performed from ventral oral anterior, ventral oral posterior and adjacent reticular thalamic nuclei. Autocorrelation functions and spectral density functions for the activity of 44 cells were analyzed. In patients with parkinsonism and double athetosis a number of cells (48%) with rhythmic activity were revealed. Regular fluctuations of background neuronal discharges with different frequencies were observed: in the range of thetha-rhythm (5-7 Hz), deltha-rhythm (1-4 Hz), with second (2-10 s) and decasecond (15-40 s) periods. The possibility of simultaneous presence of several regular periodic processes was established: in 8 neurons 2 or 3 waves of acceleration and slowing down of spike discharges have occurred. The question is discussed about the origin and the significance of rhythmic fluctuations of thalamic neuronal discharges.