New pathophysiology of Parkinson's disease revealed by posteroventral pallidotomy.

Since the failure of levodopa therapy to maintain long-term symptom relief in Parkinson's disease, posteroventral pallidotomy has seen a dramatic increase in use and interest. It has significantly reduced both the akinetic and hyperkinetic symptoms of Parkinson's disease while requiring most patients to maintain preoperative levodopa doses. Here we review the clinical results of over 300 posteroventral pallidotomies and pathophysiology of Parkinson's disease in relationship to different neurotransmitters and medical therapy.