Comparison of UPDRS III score between young and late onset Parkinson disease after deep brain stimulation: A meta-analysis

PURPOSE: Parkinson disease (PD) is a common age-related neurodegenerative disease. Subthalamic nucleus deep brain stimulation (DBS) is a safe and effective surgical treatment for medically resistant advanced PD. However, the relationship between the age at PD onset and the efficacy of subthalamic nucleus DBS surgery remains unclear. Thus, we conducted a meta-analysis to compare motor symptom improvements after DBS for the treatment of young-onset and late-onset PD. METHODS: We systematically searched the Medline and Embase databases (from inception to March 2023) for English publications. All published studies comparing the outcomes (Unified Parkinson’s Disease Rating Scale part III [UPDRS III] scores) of DBS between the young-onset Parkinson disease (YOPD) and late-onset Parkinson disease (LOPD) groups were identified. The effect size was defined as the standardized mean difference (Hedge g) with 95% confidence intervals. The standardized mean difference was calculated by dividing the difference in UPDRS III scores between old and young patients by the pooled and weighted standard deviations. The meta-analysis was performed using R Statistical Software version 4.2.2 (The R Foundation for Statistical Computing). RESULTS: Six studies were eligible for inclusion. The standardized mean difference of UPDRS III score between young and old patients ranged from −0.54 to 1.43 with a pooled difference of 0.0932 (95% confidence intervals: − 0.4666 to 0.6530, I(2) = 86.77%). Subgroup analyses were performed with a cutoff age of 65 years and did not show a significant difference in UPDRS III scores between patients with YOPD and LOPD (0.1877, −0.6663 to 1.0417). CONCLUSIONS: The efficacy of DBS in patients with YOPD and LOPD showed similar improvements in the UPDRS score; hence, DBS should be considered, if necessary, regardless of the onset age of PD.