Unilateral pallidotomy versus bilateral subthalamic nucleus stimulation in PD - A randomized trial

Objective: To compare the efficacy of unilateral pallidotomy and bilateral subthalamic nucleus (STN) stimulation in patients with advanced Parkinson disease (PD) in a randomized, observer-blind, multicenter trial. Methods: Thirty-four patients with advanced PD were randomly assigned to have unilateral pallidotomy or bilateral STN stimulation. The primary outcome was the change from baseline to 6 months in the motor part of the Unified PD Rating Scale (motor UPDRS) in the off phase. Secondary outcomes were parkinsonian symptoms in the on phase (motor UPDRS), dyskinesias (Clinical Dyskinesia Rating Scale and dyskinesias UPDRS), functional status (activities of daily living UPDRS and Schwab and England scale), PD Quality of Life questionnaire, changes in drug treatment, and adverse effects. Results: The off phase motor UPDRS score improved from 46.5 to 37 points in the group of pallidotomy patients and from 51.5 to 26.5 in the STN stimulation patients (p=0.002). Of the secondary outcome measures, on phase motor UPDRS and dyskinesias UPDRS improved significantly in favor of the STN stimulation patients. Reduction of antiparkinsonian drugs was greater after STN stimulation than after pallidotomy. One patient in each group had a major adverse effect. Conclusions: Bilateral STN stimulation is more effective than unilateral pallidotomy in reducing parkinsonian symptoms in patients with advanced PD.