Long-term efficacy and mortality in Parkinson's disease patients treated with subthalamic stimulation

The objective of this study was to examine the clinical outcome and mortality of long-term deep brain stimulation of the subthalamic nucleus in advanced Parkinson's disease.

We included all 144 patients (mean age, 60.3 years; mean disease duration, 11.0 years) treated in our center from 2001 to 2007.

Twelve months after surgery, the off-medication Unified Parkinson's Disease Rating Scale motor score was reduced by a mean of 53%, and the annual increase after surgery was 3.2 points. The daily dose of dopaminergic medication was reduced by a mean of 49% and increased only marginally during follow-up. Twelve of the 144 patients died in the study period, including 2 suicides (1.4%). Survival was 97% after 3 years and 90% after 5 years.

The study confirms the stable efficacy of long-term subthalamic stimulation in selected patients with advanced Parkinson's disease. Throughout the study the patient characteristics at time of surgery changed, with less severe disease and shorter disease duration toward the end of the study period.