The effect of Deep Brain Stimulation on Sleep-Related Symptoms

Abstract

Deep brain stimulation (DBS) is an established neuromodulatory intervention for movement disorders, but its impact on sleep in Parkinson’s disease (PD) remains unclear. To address this gap, we conducted a single, integrated investigation combining a systematic review and meta-analysis of published studies with a secondary data analysis of the Parkinson’s Progression Markers Initiative (PPMI). First, we systematically reviewed all peer-reviewed reports of sleep outcomes following DBS across various targets and clinical populations. Random-effects meta-analysis revealed small, inconsistent changes in subjective sleep measures, with high between-study heterogeneity (I² > 70%) and mixed results in PD cohorts, indicating a lack of consensus on the direction and magnitude of DBS effects on sleep. Next, we analyzed cross-sectional data from 970 PD participants in PPMI—102 with chronic DBS (≥ 6 months post-implant) and 868 without stimulation. Subjective sleep was assessed via the Epworth Sleepiness Scale (ESS) and three MDS-UPDRS Part I items (sleep problems, daytime somnolence, and fatigue). We applied inverse probability-weighted linear and logistic regression models, adjusting for age at onset, Hoehn & Yahr stage, MDS-UPDRS III motor score, levodopa equivalent daily dose, psychiatric comorbidity, pain, urinary incontinence, and sex. Sensitivity analyses—including propensity score matching and ridge regression—confirmed the robustness of our findings. Across both components, DBS was associated with modestly higher sleepiness (mean ESS increase of 1.06 points, 95% CI 0.08–2.35), greater sleep problem scores (0.53; 0.19–0.78), and increased fatigue (0.33; 0.12–0.62), with a non-significant trend for daytime somnolence (0.13; –0.06–0.43). Notably, urinary incontinence modified the effect, suggesting autonomic dysfunction as an important effect modifier. These integrated results indicate that DBS may subtly exacerbate certain sleep-related symptoms in PD, with interindividual factors such as autonomic impairment influencing outcomes. Future longitudinal research employing objective measures (polysomnography, actigraphy) is needed to clarify causal pathways and optimize stimulation protocols to minimize adverse sleep effects.