Motor, cognitive, and behavioral performance following unilateral ventroposterior pallidotomy for Parkinson disease

Objective: To evaluate the effects of ventroposterior pallidotomy on motor disability and on behavior and cognition in patients with medically intractable idiopathic Parkinson disease. Design: Detailed motor testing both while receiving and discontinuing levodopa medication, posturography, and neurocognitive and behavioral assessments were performed before and 3 to 6 months after unilateral ventroposterior pallidotomy. Setting: University-based movement disorder program. Patients: Thirty-two patients without dementia with medically refractory idiopathic Parkinson disease were studied. Main Outcome Measures: Motor function and disability were measured using the Unified Parkinson's Disease Rating Scale, Hoehn and Yahr stage, and the Schwab and England Activities of Daily Living Scale. Dynamic balance was measured by sway (amplitude and velocity) using the Chattecx Balance System. Detailed cognitive and behavioral assessments were also performed both before and after surgery. Results: Eighty-three percent of patients experienced improvement of their total Unified Parkinson's Disease Rating Scale score at 3 to 6 months after surgery. Significant improvements were also seen in the contralateral Unified Parkinson's Disease Rating Scale motor subscore (78%) as well as in the contralateral Unified Parkinson's Disease Rating Scale total score both during the on and off peroid (78% and 79%, respectively). The Hoehn and Yahr stage, Schwab and England Activities of Daily living Scale score, and dynamic balance when standing on foam also improved following unilateral pallidotomy in many patients. Cognitive performance remained relatively unchanged following surgery with the exception of category fluency, which exhibited a modest decline (P<.04). A significant improvement in depression was found on the Beck Depression Inventory. Conclusions: Ventroposterior pallidotomy significantly improves motor performance and daily, level of function in Parkinson disease. Cognition and behavior are not adversely affected in patients without dementia, and a cognitive screening battery is proposed.