Effect of electric stimulation or lesion of the thalamus on cerebral circulation

: Local cerebral blood flow (lCBF) in the thalamus and cerebral cortex was determined in 16 alert rabbits after electric stimulation of thalamic nuclei, and in 22 anesthetized dogs after thermocoagulation of posterior part of the thalamus. The cerebrovascular dilatory effect and increase in the lCBF were observed. Rheoelectroencephalographic investigations in 13 patients with parkinsonism subjected to stereotaxic lesion of thalamic ventrolateral nuclei also showed a diffuse reduction of arterial tone and cerebrovascular resistance. The data obtained seem to explain the reactive hyperemia which may develop primarily as a neurogenic reaction and then be maintained by metabolic changes.