To demonstrate that intervention targeting the primary motor area (M1) using transcranial Direct Current Stimulation can improve sleep symptoms in patients with Parkinson's disease.

Rapid eye movement sleep behavior disorder (RBD) is one of the most common accompanying symptoms of Parkinson's disease (PD). PD-RBD patients have more severe clinical manifestations, require larger drug doses, and have more non-motor symptoms. Although several strategies using transcranial direct current stimulation (tDCS) have been investigated for the treatment of sleep disorders, the efficacy of high-definition tDCS (HD-tDCS) in PD-RBD patients remains unclear.

We conducted an open-label study using the RBD-SQ to identify individuals with possible RBD (pRBD), and recruiting the patients at the First Affiliated Hospital of Anhui Medical University to receive cathodal HD-tDCS intervention. On the basis of conventional anti-PD drugs, cathodal HD-tDCS treatment was performed on the left M1 area once a day for 20 minutes, and the treatment was continued for 10 days. The International Movement Disorders Society Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the Hoehn & Yahr staging scale (H&Y), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), RBD Screening Questionnaire Hong Kong (RBDSQ- HK), Pittsburgh sleep quality index (PSQI), Epworth Sleepiness Scale (ESS), and Parkinson disease sleep scale (PDSS) were assessed on intervention Day 1 and Day 10, and clinical efficacy was evaluated by comparing the scale scores before and after the intervention.

Inclusion Criteria:

1. The diagnosis of PD was determined by neurologists with rich clinical work experience, and was in line with the diagnostic criteria for Parkinson's disease in China (2016 edition).
2. The total score of RBD Screening Questionnaire (RBDSQ) is ≥6 points.
3. All patients took the drug stably and had no history of drug adjustment within 2 months before treatment. The test was conducted 2 hours after taking the drug.
4. Good compatibility, with a certain degree of compliance;
5. Normal mental condition, able to cooperate with behavioral tests and transcranial electrical stimulation treatment;

Exclusion Criteria:

1. The patient has a metal object or skull brace device or any similar metal object on the scalp;
2. Head tremor or limb shaking is so severe that it is difficult to calmly receive treatment;
3. The presence of other serious mental illness (such as major depression, psychosis or obsessive-compulsive disorder, physical illness or a history of substance abuse);
4. Have a head injury, stroke or other neurological disorder;
5. The diagnosis of PD dementia is difficult to complete the assessment.