This study is a double blind comparative study examining the effectiveness of the transcutaneous auricular vagus nerve stimulation treatment on Parkinson's disease patients . We hypothesize that treatment using transcutaneous auricular vagus nerve stimulation will improve gait impairments and cortical activity in Parkinson's disease patients.

Patients in the Experimental group underwent seven consecutive daily sessions of transcutaneous auricular vagus nerve stimulation (taVNS, twice daily, 30 minutes each time) , whereas patients in the sham stimulation group underwent seven consecutive daily sessions of sham taVNS. Assessments of gait function, motor symptoms and cortical activity (using Functional near-infrared spectroscopy) were performed two times: at baseline, one day post intervention.

Inclusion Criteria:

1. Idiopathic Parkinson's disease (PD), as diagnosed by a neurologist.
2. Hoehn and Yahr stage ≤ 2 during ON medication state.
3. Age between 40 and 80 years old.
4. Mini-Mental State Examination score >24.
5. Ability to walk at least 60s independently.
6. Stable medication

Exclusion Criteria:

1. Patients with significant visual impairment or coexisting local or systemic diseases (e.g. osteoarthritis or other neurological conditions) likely to affect gait were excluded from our study.
2. Patients who underwent deep brain stimulation surgery or those with an implanted cardiac pacemaker were also excluded
3. Patients with known or suspected cardiovas-cular disease, uncontrolled hypertension or recent myocardial infarction were also excluded from the study.

Double (Participant, Outcomes Assessor)