The effects of deep brain stimulation on sleep: a systematic review and meta-analysis.

Background: Deep brain stimulation (DBS) is a standard treatment for movement disorders, epilepsy, and others, yet its influence on postprocedural sleep quality remains an under-researched topic. Study Objectives: We performed a systematic review and meta-analysis of all DBS effects on sleep. Methods: The use of preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA) was utilized. We extracted demographic data, disease type/duration, DBS target, stimulation laterality (unilateral vs bilateral), follow-up lengths, and sleep pre/post-op measurements with polysomnography or across four standard sleep scales. The Cochrane methodology for evaluating RCTs was employed using the risk of bias assessments, data synthesis, and statistical methods, including forest plots (risk ratio; M-H random effects; 95% CI). Results: Sixty-three studies were included in the overall analysis, representing 3022 patients. In a subgroup meta-analysis of subthalamic nucleus (STN) DBS for Parkinson's disease (PD), patients showed significant sleep improvement at three but not 12 months postoperatively with PDSS, at 12 but not 3 months with Epworth sleep scale, and at 6 months with nonmotor symptom scale. Pittsburgh sleep quality index (PSQI) showed no significant improvement in sleep at any time. Bilateral DBS showed significantly more improvement than unilateral DBS in the PSQI at 6 but not 3 months. Polysomnography showed significant sleep improvement at 1 week but not at 3 or 6 months. Most studies showed no significant sleep improvement for globus pallidus internus, centromedian thalamus, and ventral intermediate nucleus DBS. Conclusions: STN-DBS for PD likely improves sleep; however, significant standardization in sleep scale outcome reporting and follow-up time is needed to effectively determine the target-dependent effects of DBS surgery on sleep.