Spinal Cord Stimulation for the Treatment of Motor Deficits in People With Spinal Muscular Atrophy - Upper Limb

SMA Participant Inclusion Criteria:

1. Subject has a diagnosis of 5q-autosomal recessive SMA confirmed by determination ofa genetic deletion in the SMN1 gene (5q12.2-q13.3).

2. Subject is diagnosed as being non-ambulatory SMA based on the following criteria: a. Can't stand independently.

3. Subject is ≥16 years of age and < 65 years of age.

4. Subject is able to sit independently.

5. A minimum score of 1 for Entry Item "A" of the Revised Upper Limb Module (RULM)scale for SMA: "Can use hands to hold pencil or pick up a coin/token or drive apowered chair, use phone key pad"

6. Subject (and subject's parent or legal guardian if subject is a minor) is willingand able to comply with scheduled visits and study procedures

7. Participants must have started SMN inducing therapies (Spinraza or risdisplam) atleast 6 months prior to enrollment. (They must have either gotten their firstinjection at at least 6 months prior, or they started daily intake of risdisplam atleast 6 months prior to the study)

Healthy Control Participant Inclusion Criteria:

1. Subject is ≥18 years of age and < 65 years of age.

2. Subject is able to stand independently for ≥3 seconds.

3. Subject is willing and able to comply with scheduled visits and study procedures.

SMA Participant Exclusion Criteria:

1. Subject has deformation of the spinal canal preventing lead implantation as judgedby the study neurosurgeon

2. Subject has size of spinal canal that is insufficient for lead implantation asjudged by the study neurosurgeon

3. Subject has moderate or severe joint contractures that would affect ability toperform study measures, determined by the study physician

4. Subject has severe behavioral or cognitive problems that preclude participation inthe study, in the opinion of the investigator

5. Subject has previous or ongoing medical condition, medical history, physicalfindings or laboratory abnormalities that could affect safety of anesthesia or theprocedures, make it unlikely that intervention or follow-up will be correctlycompleted or impair the assessment of study results, in the opinion of theinvestigator

6. Female subjects are pregnant or breastfeeding, as established by self-report.

7. Subject has severe claustrophobia

8. Subject is on anticoagulant, anti-spasticity or anti-seizure medication within 4weeks of lead implantation or requires these medications during the treatment phaseof the study

9. Subject has medical implant that precludes magnetic resonance imaging

10. Subject has a deconditioned respiratory system, per the discretion of the physicianinvestigator.

11. Subjects with renal insufficiency at the discretion of the physician investigator.

12. Subjects requiring any form of sedation for MRI will be excluded.

Healthy Control Participant Exclusion Criteria:

1. Subject has severe behavioral or cognitive problems that preclude participation inthe study, in the opinion of the investigator would impact participation in thestudy.

2. Participants who have any serious disease or disorder (e.g. cancer, severe cardiacor respiratory disease, neurological conditions other than stroke, etc.) orcognitive impairments that could affect their ability to participate in this study.

3. Female subjects are pregnant or breastfeeding, as established by self-report.

4. Subjects requiring sedation for MRI will be excluded.