Does ageing influence deep brain stimulation outcomes in Parkinson's disease?

We sought to define the influence of ageing in clinical, cognitive, and quality-of-life outcomes after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD). We performed motor assessment (UPDRS), mood tests, cognitive, and quality of life evaluation (PDQ-39) on PD patients before surgery, and 12 and 24 months after, and we recorded adverse events. The variations of these parameters after surgery were correlated with age using regression statistical tests. Cerebral bleeding risk was evaluated by a nonparametric test. We enrolled 45 patients (mean age 60 +/- 9 years, range 40-73). No significant correlation was found between age and motor scores and PDQ-39 improvements at 12 months. At 24 months, there was a significant negative correlation between age and the improvement of three dimensions of PDQ 39 (mobility, activities of daily life, and cognition). Cognitive impairment showed no correlation, but apathy and depression were positively correlated with age. Significant statistical difference was observed between cerebral bleeding and age. STN-DBS is an effective treatment for elderly patients with advanced PD. A longer follow-up duration and a larger population seem necessary to better assess the quality of life perception in elderly patients and to determinate the real risk of hemorrage.