Comparison of the Effectiveness of Cerebellar Transcranial Alternating and Direct Current Stimulation on Balance in People with Cerebellar Ataxia

A comparison of cerebellar transcranial alternating and direct current stimulation effects on balance in people with cerebellar ataxia

A randomized, Phase III, multi-center, double-blind, crossover, sham-controlled clinical trial with a sample size of 36 patients. Randomization will be carried out using block randomization through a web-based service.

All participants will randomly receive three single-session interventions, including anodal tDCS, tACS, and sham stimulation, at the Musculoskeletal Research Center in Isfahan and the Mobasher Kashani Rehabilitation Center in Hamadan. Both the participants and the outcome assessor are blinded to the type of intervention. A 1-week washout period will be considered between intervention sessions. Immediately before and after each intervention, balance will be assessed.

Inclusion criteria: Individuals with cerebellar ataxia diagnosed by a neurologist; Individuals with standing impairment scored between 1 and 4 based on the scale for the assessment and rating of ataxia; Individuals with gait impairment scored between 3 and 8 based on the scale for the assessment and rating of ataxia. Exclusion criteria: Individuals with a history of neurological, psychiatric, or cognitive disorders; Use of medications that impair balance; Pregnancy; Persons with uncorrected visual impairments.

Intervention 1: Transcranial direct current stimulation، 2 milliampere current intensity, 20 minutes of stimulation Intervention 2: Transcranial alternating current stimulation، 2 milliampere current intensity, 40 hertz frequency, 20 minutes of stimulation Intervention 3: Sham transcranial direct or alternating current stimulation, the current will be applied only for the first 30 seconds.

Static balance; Dynamic balance

Participants will be recruited consecutively and randomly allocated to groups using block randomization via a web-based system. Allocation concealment will be ensured through the use of sequentially numbered, opaque, sealed envelopes

The outcome assessor and participants will be blinded to the type of intervention. To maintain participant blinding, participants will be unaware of whether the stimulator is active. To ensure assessor blinding, the stimulation protocols will be administered by the principal investigator, who will not be involved in outcome assessment

Only part of the static and dynamic balance data of individuals can be shared

The data access period starts 6 months after the publication of the results

For researchers at academic and scientific institutions only

Ethical approval: Researchers must provide the necessary approval from their institutional ethics committee or the central ethics committee. Non-disclosure agreement: Signing a non-disclosure agreement and maintaining the confidentiality of the data are mandatory. Time limitation: Access to the data will be granted after approval and for 6 months after the publication of the results. Citation of source: In any report, article, or presentation prepared based on these data, the original source of the data must be accurately cited. Privacy protection: Researchers must fully adhere to the principles of protecting participant privacy and anonymizing the data.

Ailin Talimkhani, Assistant Professor of Physiotherapy, Department of Physiotherapy, School of Rehabilitation Sciences, Hamadan University of Medical Sciences

Once approved, the anonymized dataset is prepared and quality-checked by the research team. The data is then released either through a secure data-sharing platform or after signing a Non-Disclosure Agreement. Estimated total time is 5–7 working days.