Sleep-Related Outcomes of Deep Brain Stimulation: A Systematic Review

Introduction: Effects of deep brain stimulation (DBS) on sleep have been studied concerning individual diseases, like Parkinson’s disease (PD) or depression, but sleep effects across targets and progression over time remain unclear. To this end, we conducted a systematic review of sleep outcomes following DBS.

Methods: A systematic search was performed in PubMed, Embase, and Web of Science for studies conducted up to October 1, 2023. Studies conducted in English that measure the effect on sleep after DBS surgery were selected. From the identified studies, we extracted demographic data, disease type and duration, DBS target, sleep pre/post-op measurements across four scales (ESS, PDSS, PQSI, NMSS), and follow-up lengths.

Results: A total of 1995 studies were screened. From 197 full-texts screened for eligibility, 55 were included, representing 1853 patients (60.9 ± 8.5 years old). Nine targets and five diseases were identified. Across all targets and indications, 1665 (71.5%) patients had a significant improvement in sleep quality, 624 (26.8%) patients had no significant change in sleep quality, and 40 (1.7%) patients had a significant decrease in sleep quality. The average change in ESS, NMSS, PDSS, and PSQI scales post-DBS surgery were -19.3 ± 22%, -45.5 ± 20%, 16.9 ± 17.8%, and -18.5 ± 16.7%, respectively. When comparing outcomes among follow-up times of less than or equal to 6 months, 7-12 months, or greater than 12 months, we found no significant difference, with 74.4%, 64.6%, and 75.6% of patients reporting improvement, respectively. Limited number of patients/studies across all target areas and diseases prevented robust statistical analyses.

Conclusion : Sleep quality is generally significantly improved, regardless of indication and target, in patients after DBS surgery. No significant difference in sleep outcomes was found as a function of follow-up time after surgery. Additional investigations across lesser-studied targets and diseases are needed to conclude target- and disease-dependent differences.