Ten-Year Outcome of Subthalamic Stimulation in Parkinson Disease: A Blinded Evaluation
Castrioto A, Lozano AM, Poon YY, Lang AE, Fallis M, Moro E
Arch Neurol. 2011;68:1550-1556
Study Summary
The goal of this prospective study was to evaluate motor outcomes at 10 years following deep-brain stimulation of the subthalamic nucleus (STN-DBS) in patients with advanced Parkinson disease (PD). At the Movement Disorders Centre of the University of Toronto in Canada, 18 participants treated with bilateral STN-DBS for PD underwent the Core Assessment Program for Surgical Interventional Therapies in PD protocol and videography at baseline and 1, 5, and 10 years after surgery. Ten-year videotape scoring was performed by an independent rater masked to stimulation treatment and medications received by the participants.
The change in blinded Unified PD Rating Scale (UPDRS) motor scores/subscores between the no-medication/stimulation condition compared with the no-medication/no-stimulation condition at 10 years was the main study endpoint. Changes in blinded UPDRS motor scores between the medication/no-stimulation and medication/stimulation conditions were the secondary endpoints, as well as UPDRS II scores, UPDRS IV dyskinesia and motor fluctuations scores, and anti-PD medication dose (levodopa-equivalent daily dose) at different points.
At 10 years, STN-DBS was still associated with significant improvements in the UPDRS total motor score (P = .007) and in the resting tremor (P < .01), action tremor (P = .02), and bradykinesia (P = .01) subscores. Compared with baseline, the UPDRS II scores in the medication and no-medication conditions, UPDRS IV dyskinesia and motor fluctuations scores, and levodopa-equivalent daily doses were all significantly reduced. The most progressive deterioration in stimulation and levodopa response during the 10-year follow-up was evident in axial signs.
The incidence of adverse effects at 10 years was not significantly different from the adverse effect rates at 1 and 5 years. Two patients had serious device-related infections between 5 and 10 years after surgery.