Chronic subthalamic deep brain stimulation and multidomain sleep outcomes in Parkinson disease: a controlled cross-sectional study from a Turkish cohort

Background Sleep disturbances and daytime dysfunction are common non-motor manifestations of Parkinson disease and substantially affect quality of life. Subthalamic deep brain stimulation is an established therapy for motor complications; however, its long-term effects on multidomain sleep outcomes remain incompletely characterized. This controlled cross-sectional study evaluated subjective sleep quality and daytime function in patients with chronic bilateral subthalamic stimulation compared with a medically treated control group. Methods In this single-center cross-sectional comparative study, 25 patients with bilateral STN-DBS who were at least six months post-implantation and 30 medically treated patients with Parkinson disease underwent standardized subjective sleep assessments under stable treatment conditions. Multiple sleep-related comparisons were controlled using the Benjamini–Hochberg false discovery rate procedure, and exploratory multivariable models accounted for age, disease duration, and motor phenotype. Results Total Pittsburgh Sleep Quality Index scores did not differ significantly between groups. Nominal unadjusted differences were observed for the sleep-medication use and daytime dysfunction components; however, neither remained statistically significant after false discovery rate correction. In multivariable analyses, STN-DBS status was not statistically associated with either component after adjustment for age and disease duration, and additional adjustment for motor phenotype did not materially alter the findings. No statistically robust between-group differences were identified across the multidomain subjective sleep measures assessed. Conclusions In this exploratory cross-sectional cohort, we did not identify statistically robust between-group differences in subjective multidomain sleep outcomes after accounting for multiple comparisons and selected clinical covariates. These findings do not establish the absence of a stimulation-related effect and should be interpreted in light of the cross-sectional design. Prospective longitudinal studies incorporating repeated sleep assessments and detailed clinical and stimulation-related factors are needed to clarify the temporal and domain-specific associations between STN-DBS and sleep.