Curative Effect and Mechanism of Transcutaneous Auricular Vagus Nerve Stimulation on Sleep Disorders of PD

Study on the Efficacy and Mechanism of Transcutaneous Auricular Vagus Nerve Stimulation in the Treatment of Sleep Disorders in Parkinson's Disease

This study is a double-blind comparative study examining the curative effect and mechanism of the transcutaneous auricular vagus nerve stimulation treatment on non-motor symptoms of Parkinson's disease patients. The investigators hypothesize that treatment using transcutaneous auricular vagus nerve stimulation will improve the non-motor symptoms, such as improving sleep, and improve cortical activity simultaneously in Parkinson's disease patients.

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

Inclusion Criteria:

(i) right-handed individuals aged 45-80 years; (ii) met the diagnostic criteria for idiopathic PD and had been stable on medication for at least one month; (iii) met the diagnostic criteria for insomnia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and insomnia had to have lasted for at least six months, with Pittsburgh sleep quality index (PSQI) scores >7; (iv) no history of medication that might affect the study, such as sleeping pills or antidepressants, that is, the PSQI hypnotic medication score of 0; (v) clear consciousness, basic communication skills and cooperation in all assessments and treatments; (vi) The patients agreed to participate in the study and signed an informed consent form.

Exclusion Criteria:

(i) those with concomitant cognitive dysfunction, such as Montreal cognitive assessment (MoCA) <23; (ii) those with secondary Parkinson's syndrome or Parkinson's superimposed syndrome; (iii) those with severe cardiac, pulmonary, hepatic, renal, or concomitant malignancies or a history of previous brain surgery; (iv) those with contraindications to taVNS interventions; (v) those with severe psychiatric disorders; (vi) Insomnia not caused by PD, such as frequent (two times per week) nighttime use of sedative medications (including sedative antidepressants), untreated restless legs syndrome, night-shift work or other occupations that result in abnormal sleep patterns, insomnia associated with dopamine therapy, and other reversible causes of insomnia identified by the baseline clinical interview.