Treatment of Transcranial Alternating Current Stimulation（tACS）on Cerebellar Ataxia

Transcranial alternating current stimulation (tACS) is a relatively recent method that noninvasively modulates brain oscillations, and can effectively stimulate deep brain regions, affect brain rhythm, increase neural plasticity, change neurotransmitter levels, and improve brain function. It is a comfortable, safe, effective, non-invasive, and easy-to-operate method, which means it has development potential in relevant medical fields. It has been approved by the FDA for clinically treating neuropsychiatric diseases.

This is a prospective, longitudinal, triple-blind, randomized-controlled, interventional study designed to evaluate the efficacy, safety, and tolerability of tACS in patients of SCA3 and MSA-C in China. Based on typical guidelines, we will use the tACS paradigm (bilateral mandible as a place for active electrode stimulation electrode, and the inion for the return electrode). This study has two parts. The patients studied in the Part Ⅰ are SCA3. The patients studied in the Part Ⅱ are MSA-C. Every part of study, subjects will be randomized into two groups, one receiving a 10-day (5 days/week for 2 weeks) treatment with real cerebellar tACS (CB-tACS) and the other receiving a sham stimulation. The patient's motor function, cognitive function, sleep, mental state, plantar pressure, and magnetic resonance imaging will be assessed before and after the intervention.

There will be a total of 4 visits. All patients receiving tACS will be visited face to face at baseline, day 1, day 30, and day 90 after the treatment begins.

Inclusion criteria

• for SCA3

• Patients with detectable clinical signs and confirmed genetic diagnosis with SCA3
• SCA3 patients aged 18 - 80 years
• Patients or their family members have informed consent to the study and signed relevant documents
• The pre-study ataxia Assessment Score (SARA) ranged from 3 to 30
• for MSA-C

• Aged 30-80 years
• Diagnosed as clinically determined (Established)MSA-C or clinically Probable MSA-C according to the latest MSA diagnostic criteria
• No more than 8 years after diagnosis of MSA-C
• Able to walk independently or with assistance
• Have a life expectancy of at least 3 years
• Women of childbearing age with MSA need to use contraceptive measures

Exclusion criteria

• Patients who have concomitant epilepsy.
• Patients with a serious cognitive disorder, behavioral disorder, or mental illness
• Patients with a history of seizures, stroke, encephalitis, or other degenerative neurological diseases
• Patients with a serious medical disease

• Patients who concomitantly suffer from severe renal impairment, convulsions, stomach ulcers, or moderate or more severe liver disease
• Patients with uncontrolled high blood pressure or diabetes
• History of head injury or neurosurgical interventions.
• History of any metal in the head (outside the mouth).
• Known history of any metallic particles in the eye, implanted cardiac pacemaker, implanted neurostimulators, surgical clips (above the shoulder line), or any medical pumps.
• Patients who have taken other investigational products within 4 weeks before being enrolled in this clinical trial, or patients who are pregnant or breastfeeding.