Effects of repetitive transcranial magnetic stimulation over right dorsolateral prefrontal cortex on excessive daytime sleepiness in patients with Parkinson's disease.

ABSTRACT

BACKGROUND: Excessive daytime sleepiness (EDS) is a common sleep disorder in Parkinson's disease (PD), which seriously affects patients' quality of life. Repetitive transcranial magnetic stimulation (rTMS) can be used as an add-on therapy to a variety of non-motor symptoms of PD. However, little is known on the treatment of EDS in PD patients. OBJECTIVE: To explore the effects of low frequency rTMS over right dorsolateral prefrontal cortex (DLPFC) in the treatment of EDS in PD. METHODS: We conducted a sham-controlled, parallel study including 25 individuals of PD with possible EDS based on Epworth Sleepiness Scale (ESS ≥8 points) and randomly divided them into active group (n = 15) and sham group (n = 10). 1 Hz rTMS was administrated over right DLPFC for 10 consecutive days. In the active group, we further classified them into responsive group and non-responsive group according to change of ESS score in comparison with baseline. Clinical assessments on motor and non-motor symptoms were completed at baseline, at the end of treatment and 1 month after treatment. RESULTS: Compared to baseline, active group showed significant improvement on ESS score 10 days and 1 month after treatment (P < 0.05 for both). The percentage change of ESS score was positively related to disease duration during follow-up. No significant changes were observed on ESS score change in the sham group. Further analysis of individuals in the active group showed that, relative to those with non-response to rTMS, individuals with therapeutic response exhibited longer disease duration and lower baseline levodopa equivalent dose. CONCLUSION: Low frequency rTMS over right DLPFC may improve symptoms of EDS in PD.