EFFECT ON PARKINSONIAN SIGNS AND SYMPTOMS OF BILATERAL SUBTHALAMIC NUCLEUS STIMULATION

In monkeys rendered parkinsonian, lesions and electrical stimulation o f the subthalamic nucleus reduce all major motor disturbances, The eff ect of electrical stimulation of the subthalamic nucleus was assessed in three patients with disabling akinetic-rigid Parkinson's disease an d severe motor fluctuations. Quadripolar electrodes connected to a pul se generator were implanted in the subthalamic nuclei on both sides, P atients were evaluated with the unified Parkinson's disease rating sca le and timed motor tests. 3 months after surgery, activities of daily living scores had improved by 58-88% and motor scores by 42-84%. This improvement was maintained for up to 8 months in the first patient ope rated upon. One patient was confused for 2 weeks after surgery, and an other developed neuropsychological impairment related to a thalamic in farction which improved over 3 months, In one patient, stimulation cou ld induce ballism that was stopped by reduction of stimulation. This i s the first demonstration in human beings of the part played by the su bthalamic nuclei in the pathophysiology of Parkinson's disease.