Overview

The goal of this clinical trial is to test the safety of placing Deep Brain Stimulators (DBS) in the cerebellum and using electrical stimulation of that part of the brain to treat symptoms related to the participants spinocerebellar ataxia. Five adults diagnosed with spinocerebellar ataxia type 6 (SCA6) with inadequate cerebellar symptom relief will be implanted with a Medtronic Percept Primary Cell Neurostimulator. The device will be implanted into the dentate nucleus, which is a structure located within the cerebellum that is responsible for controlling movement and balance.

Specifically, the investigators will be using adaptive deep brain stimulation (aDBS), which analyzes brain signals and automatically adjusts the strength, timing, and pattern of stimulation according to the patient's needs at any given moment. This study will evaluate the feasibility, safety, and tolerability of aDBS in SCA6 patients.

Eligibility

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.