Effects of deep brain stimulation on functional autonomy and quality of life in Parkinson's disease: A systematic review and meta-analysis.

BackgroundDeep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established therapy for advanced Parkinson's disease (PD), primarily targeting motor complications refractory to pharmacological treatment. However, its long-term impact on functional autonomy and quality of life (QoL) remains debated.ObjectiveThis systematic review with meta-analysis aimed to evaluate the effects of STN-DBS on autonomy and QoL in people with PD.MethodsFollowing PRISMA guidelines, a systematic search of PubMed, Scopus, Embase and Web of Science was conducted to identify studies including adults with PD treated with STN-DBS and reporting measures of autonomy and/or quality of life.ResultsThirty-two studies met inclusion criteria. Meta-analyses showed effect estimates favoring DBS at 6 months (SMD = 0.83[0.38;1.29]) and at 1 year (SMD = 0.49[-0.02;0.99]) for autonomy. Similar trends were observed for QoL, with SMD = 0.60[0.49;0.71] at 6 months and SMD = 0.48[0.0;0.96] at 1 year.At 2 years, small but significant pooled effects persisted, for both autonomy SMD = 0.40[0.13;0.67] and QoL SMD = 0.25[-0.04;0.53]. However, at 5 years, pooled effects were no longer statistically significant for either autonomy SMD = 0.37[-0.55;1.29] or QoL SMD = -0.01[-0.25;0.22], indicating a progressive attenuation of benefit over time.ConclusionsSTN-DBS provides robust short- and mid-term benefits in functional autonomy and QoL in PD. Long-term outcomes are variable and influenced by disease progression and non-motor symptoms. Standardized outcome reporting, larger multicenter trials, and integration of rehabilitative and psychosocial interventions are needed to optimize benefits.