Adaptive deep brain stimulation in the cerebellum for spinocerebellar ataxia type 6

Adaptive Deep Brain Stimulation Targeting the Dentate Nucleus to Treat Spinocerebellar Ataxia

This will see if an implanted adaptive deep brain stimulator placed in the cerebellum can reduce movement and balance problems in adults with SCA6 who still have symptoms.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 5 (estimated)
• Ages: 21 Years to 89 Years
• Sex: All
• Sponsor: University of California, San Francisco (Academic / other)
• Locations: 2 sites (San Francisco, California and 1 other locations)
• Trial ID: NCT07288437 on ClinicalTrials.gov

What this trial studies

Researchers will implant a Medtronic Percept Primary Cell Neurostimulator into the dentate nucleus of the cerebellum in five adults with genetically confirmed SCA6 who continue to have cerebellar symptoms. The device uses adaptive deep brain stimulation (aDBS) that monitors brain signals and automatically adjusts stimulation strength, timing, and pattern to the patient's needs. The primary goals are to determine the feasibility, safety, and tolerability of cerebellar aDBS, with clinical scales such as SARA and cognitive screening (MoCA) guiding eligibility and outcomes. Participants will undergo surgical implantation at UCSF with scheduled postoperative follow-up visits to monitor effects and adverse events.

Who should consider this trial

Good fit: Adults aged 21–88 with genetically confirmed SCA6, a SARA total score ≥8 who can walk (gait subscore <8), able to give informed consent and with MoCA ≥21, and without implanted pacemakers or other disqualifying implants are the ideal candidates.

Not a fit: People with non‑SCA6 causes of ataxia, severe cognitive impairment, prior implanted neurostimulators or pacemakers, or who cannot safely undergo surgery are unlikely to benefit.

Why it matters

Potential benefit: If successful, cerebellar aDBS could reduce ataxia-related balance and coordination problems and improve daily functioning for people with SCA6.

How similar studies have performed: Small case reports and preclinical studies suggest cerebellar stimulation can alter ataxia symptoms, but adaptive dentate nucleus DBS for SCA6 is largely novel with limited clinical data.

Eligibility criteria

Inclusion Criteria:

1. A diagnosis of SCA6 by a Movement Disorders specialist following established criteria recommended by the Movement Disorders Society.
2. A positive genetic test for SCA6.
3. A total scale ≥ 8 on the Scale of the Assessment and Rating of Ataxia (SARA) rating scale.
4. Ability to walk with or without support (score \< 8 on the 'gait' subsection of the SARA rating scale).
5. Age ≥ 21 years and \< 89 years.
6. Ability to give informed consent for the study.
7. Be able to understand the study protocol.

Exclusion Criteria:

1. Inability or unwillingness to comply with the study protocol.
2. History of previously implanted neurostimulators, pacemakers, defibrillators, or metallic head implants.
3. Severe cognitive impairment or dementia, defined as a score \< 21 on the Montreal Cognitive Assessment (MoCA).
4. Evidence of ataxia due to other etiologies, including but not limited to:

   1. Genetic/inherited disorders other than SCA6.
   2. Acquired causes: tramautic brain injury, multiple sclerosis, paraneplastic cerebellar degeneration, infections or post-infectious cerebellitis, autoimmune ataxias (e.g., anti-GAD, gluten ataxia).
   3. Toxic/metabolic causes: alcoholic cerebellar degeneration, vitamin deficiencies.
   4. Structural, vascular, or neoplastic causes: cerebellar stroke, tumors, congenital malformations.
   5. Suspected multiple system atrophy-cerebellar type (MSA-C).
5. The presence of active and untreated psychiatric illness, severe depression (Beck Depression Inventory ≥ 21), or personality disorder at the discretion of the study team.
6. Coagulopathy, uncontrolled epilepsy, or other medical condition considered to place the patient at elevated risk for surgical complications. Presence of a concomitant medical condition that, in the investigator's opinion, may interfere with the study participation or gait/balance, for example, severe arthritis.
7. Presence of a concominant medical condition that, in the investigator's opinion, may interfere with the study participation or gait/balance, for example, severe arthritis.
8. Requirement of diathermy, electroconvulsive therapy, or transcranial magnetic stimulation.
9. Pregnancy or lactation.
10. Active suicidal ideation, defined as fined as a "Yes" response to questions #2-5 on the Columbia Suicide Severity Rating Scale, C-SSRS.
11. Refractory Epilepsy.

Where this trial is running

San Francisco, California and 1 other locations

• UCSF Weill Institute for Neurosciences — San Francisco, California, United States (Recruiting)
• University of California, San Francisco — San Francisco, California, United States (Not_yet_recruiting)

Study contacts

• Principal investigator: Marta San Luciano Palenzuela, MD, PhD — University of California, San Francisco
• Study coordinator: Marta San Luciano Palenzuela, MD, PhD

Conditions Spinocerebellar Ataxia; Spinocerebellar Ataxia Type 6; adaptive deep brain stimulation; aDBS; SCA6; DBS; deep brain stimulation