Progression and survival in Parkinson's disease with subthalamic nucleus stimulation

Background Treatment for Parkinson's disease (PD) is symptomatic. Surgical treatment with continuous high‐frequency stimulation of the subthalamic nucleus (STN‐DBS) is established as a safe symptomatic treatment with long‐term beneficial effects. It has been postulated that STN‐DBS could halt the progression of PD through a disease modifying or neuroprotective effect. Objective To investigate the postulated disease modifying or neuroprotective effect of STN‐DBS by comparing the rate of deterioration of parkinsonism and mortality over time in two selected and matched groups of patients with PD with and without surgery. Methods Group A was derived from all patients who received STN‐DSB surgery at Oslo University Hospital, from January 2001 to December 2007. Group B was derived from a prevalence study of PD in the Stavanger area of Western Norway in 1993. The two groups were individually matched and the disease progression measured by Unified Parkinson's Disease Rating Scale‐motor scores, and the mortality was compared. Results The mean annual change based on baseline and last observation scores in individually matched groups was 0.97 (SD = 3.57) for the surgery group and 1.04 (SD = 3.33) for the controls and thus not significantly different, F(1, 104) = .21, P = 0.89. The long‐term mortality was also similar in the two groups during long‐term follow‐up, hazard ratio = 1.76, CL 0.91–3.40, P = 0.091. Conclusion This study gives no support to a postulated disease modifying or neuroprotective effect of STN‐DBS in patients with PD.