Deep Brain Stimulation for Spinocerebellar Ataxia

Inclusion Criteria:

1. A diagnosis of SCA6 by a Movement Disorders specialist following establishedcriteria 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) ratingscale.

4. Ability to walk with or without support (score < 8 on the 'gait' subsection of theSARA 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, ormetallic head implants.

3. Severe cognitive impairment or dementia, defined as a score < 21 on the MontrealCognitive Assessment (MoCA).

4. Evidence of ataxia due to other etiologies, including but not limited to:

5. Genetic/inherited disorders other than SCA6.

6. Acquired causes: tramautic brain injury, multiple sclerosis, paraneplasticcerebellar degeneration, infections or post-infectious cerebellitis, autoimmuneataxias (e.g., anti-GAD, gluten ataxia).

7. Toxic/metabolic causes: alcoholic cerebellar degeneration, vitamindeficiencies.

8. Structural, vascular, or neoplastic causes: cerebellar stroke, tumors,congenital malformations.

9. Suspected multiple system atrophy-cerebellar type (MSA-C).

10. The presence of active and untreated psychiatric illness, severe depression (BeckDepression Inventory ≥ 21), or personality disorder at the discretion of the studyteam.

11. Coagulopathy, uncontrolled epilepsy, or other medical condition considered to placethe patient at elevated risk for surgical complications. Presence of a concomitantmedical condition that, in the investigator's opinion, may interfere with the studyparticipation or gait/balance, for example, severe arthritis.

12. Presence of a concominant medical condition that, in the investigator's opinion, mayinterfere with the study participation or gait/balance, for example, severearthritis.

13. Requirement of diathermy, electroconvulsive therapy, or transcranial magneticstimulation.

14. Pregnancy or lactation.

15. Active suicidal ideation, defined as fined as a "Yes" response to questions #2-5 onthe Columbia Suicide Severity Rating Scale, C-SSRS.

16. Refractory Epilepsy.