Supplementary Material for: Long-Term Mortality and 10-Year Outcomes after Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease

Background: Subthalamic nucleus deep brain stimulation (STN-DBS) effectively improves motor symptoms in Parkinson’s disease (PD), but long-term survival outcomes and mortality predictors remain unclear. This study aimed to evaluate survival and 10-year clinical outcomes after STN-DBS.
Methods: We retrospectively analyzed 608 patients with PD who underwent bilateral STN-DBS between 2006 and 2023. Kaplan–Meier and Cox regression analyses assessed survival and preoperative predictors. Motor (MDS-UPDRS Part III), cognitive (MoCA, MMSE), and medication (LEDD) data were compared between baseline and 10 years postoperatively.
Results: During a mean follow-up of 4.8 ± 3.5 years, 42 deaths (6.9%) occurred, yielding an age-adjusted mortality rate of 3.3 per 100,000 population. The estimated 5- and 10-year survival rates were 95% and 77%, respectively. The most frequent cause of death was aspiration pneumonia (11.9%). In multivariate Cox analysis, lower preoperative MoCA scores (HR = 0.83, 95% CI 0.73–0.95, p < 0.01) and higher OFF-state MDS-UPDRS Part III scores (HR = 1.03, 95% CI 1.00–1.07, p < 0.05) independently predicted mortality, whereas age at surgery was not significantly associated with survival. Among 118 patients with 10-year follow-up, OFF-state motor and cognitive scores worsened significantly (p < 0.01), while ON-state motor scores (p = 0.21) and total LEDD (p = 0.06) remained stable, suggesting sustained motor control and medication-sparing effects.
Conclusions: Long-term survival after STN-DBS in PD was favorable. Preoperative cognitive and motor status, rather than age, determined long-term prognosis, emphasizing the enduring therapeutic value of STN-DBS.