Unilateral pallidotomy in Parkinson's disease: a randomised, single-blind, multicentre trial

BACKGROUND: The results of several cohort studies suggest that patients with advanced Parkinson's disease would benefit from unilateral pallidotomy. We have assessed the efficacy of unilateral pallidotomy in a randomised, single-blind, multicentre trial. METHODS: We enrolled 37 patients with advanced Parkinson's disease who had, despite optimum pharmacological treatment, at least one of the following symptoms: severe response fluctuations, dyskinesias, painful dystonias, or bradykinesia. Patients were randomly assigned to unilateral pallidotomy within 1 month or to pallidotomy after the primary outcome assessment (6 months later). The primary outcome was the difference between the groups in median changes on the motor examination section of the unified Parkinson's disease rating scale (UPDRS 3) score done in the off phase. Secondary outcome measures included levodopa-induced dyskinesias (dyskinesia rating scale [DRS]) and extent of disability (UPDRS 2). FINDINGS: The median UPDRS 3 off score of the pallidotomy patients improved from 47 to 32.5, whereas that of control patients slightly worsened from 52.5 to 56.5 (p