Unilateral pallidotomy for Parkinson's disease: speech, motor, and neuropsychological outcome measurements

We studied the effects of unilateral medial pallidotomy in the first 57 consecutive Parkinson's disease (PD) patients undergoing this MRI/electrophysiologically guided procedure at our institution, obtaining qualitative and quantitative measures of speech, motor function, activities of daily living, and neuropsychological functioning at 3 and 12months post-operatively. Speech intelligibility was typically preserved, declining mildly in one-third of patients post-operatively. Pallidotomy significantly improved motor function similarly in patients >/=65 or <65years (n=20). Cognitive abilities generally remained stable following surgery; however, performance on measures of letter fluency and semantic fluency declined in patients with left pallidotomies. We conclude that in our series mild deterioration in speech may occur with unilateral pallidotomy in patients otherwise responsive to this treatment.