Mortality in patients with Parkinson's disease treated by stimulation of the subthalamic nucleus

Subthalamic nucleus (STN) stimulation improves motor disability and quality of life in patients with advanced Parkinson's disease (PD). Short-term mortality is low, but little is known about long-term mortality. We assessed mortality and causes of death in 171 consecutive PD patients treated by STN stimulation. Surgery was performed after a median lagtime of 13 years from PD onset at a median age of 57 years. The median follow-up after surgery was 41 months. Sixteen patients died 8 to 83 months after neurosurgery. Poorer cognitive function was the only predictive factor for mortality (standardized mortality ratio = 2.9; 95% confidence interval [CI], 1.6-4.7; P < 0.0001). Based on a historical comparison of 118 operated patients with 39 nonoperated patients from a different population, survival among operated patients was not better (hazard ratio = 1.2; 95% CI, 0.7-2.1).