Exploring the effect of transcranial magnetic stimulation on quality of sleep in Parkinson’s disease

Abstract Background Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive therapeutic approach that targets particular brain regions that had been used and displayed significant impact in various neurological disorders. This study aimed to explore if high-frequency (HF) rTMS over the parietal cortex could influence sleep quality in Parkinson's disease (PD). Methods This was a prospective sham-controlled study conducted on 40 individuals with PD. The enrolled patients were examined with Unified Parkinson's Disease Rating Scale (UPDRS-III) and Modified Hoehn and Yahr Staging Scale (H&Y staging) for motor disability evaluation and staging. Pittsburgh Sleep Quality Index (PSQI) was used for sleep quality and Epworth Sleepiness Scale (ESS) for excessive daytime sleepiness and Beck Depression Inventory-II (BDI-II) for depression. Patients were classified into 2 groups: patients who underwent real-rTMS positioned over their bilateral parietal cortex. 100% of the motor threshold. Patients had a total of 12 sessions, one every other day. Another group received sham rTMS. Results The patients receiving active rTMS showed significant improvement in UPDRS-III, PSQI, ESS, and BDI-II immediately after the sessions and 1 month later. The follow-up PSQI had a significant positive correlation with the baseline BDI-II (r = 0.88, P = 0.001), H&Y staging (r = 0.78, P = 0.001), and UPDRS-III (r = 0.78, p = 0.001). Multivariate linear regression analysis exhibited that the age of the patients was a significant predictor of sleep quality. Conclusion HF rTMS over the parietal cortex had shown a significant impact on sleep quality by the modulation of affected brain areas and by improving concomitant motor and mood manifestations