Progression and survival in P arkinson's disease with subthalamic nucleus stimulation

Background Treatment for P arkinson'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 O slo U niversity H ospital, from J anuary 2001 to D ecember 2007. Group B was derived from a prevalence study of PD in the S tavanger area of W estern N orway in 1993. The two groups were individually matched and the disease progression measured by U nified P arkinson's D isease R ating S cale‐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 .