Home-based Spinal Cord Stimulation for Hand & Arm Function in MS

Inclusion Criteria: 1. Diagnosis of multiple sclerosis 2. Adult individuals between 18 and 70 years of age. 3. Impaired upper extremity function as evidenced by 9-Hole Peg Test \>33.5 sec 4. Partner or caregiver willing to provide support during intervention 5. Ability to give consent 6. For women of childbearing potential, willingness to provide confirmation of a negative over-the-counter home pregnancy test within 2 weeks of study entry and prior to each intervention arm. They must also be willing to practice adequate contraception (which may include implant, intrauterine device (IUD), injection, pill, patch, vaginal ring, or diaphragm) during the study period. Exclusion Criteria: 1. Multiple sclerosis relapse within the past 3 months (given that natural recovery from MS relapse could skew results) 2. History of seizure, active implanted stimulator (pacemaker, vagus nerve stimulator, cochlear implant, etc.) or baclofen pump 3. Upper extremity Botox injection within the past 4 months 4. Coexisting neurological condition that could interfere with interpretation of testing results (hx of stroke, traumatic brain injury, epilepsy/seizure, ALS, spinal cord injury, central nervous system vasculitis, intracranial tumor, intracranial aneurysm, cervical myelopathy/radiculopathy or peripheral neuropathy (diabetic polyneuropathy, entrapment neuropathy), etc.), 5. History of major active psychiatric illness that could interfere with treatment, such as severe depression, alcohol/drug abuse, or dementia. 6. Contraindication to transcranial magnetic stimulation 7. Serious comorbidities (e.g., cardiac arrhythmia, uncontrolled hypertension, respiratory disease, cancer, renal failure, chronic infectious disease, rheumatic disease, frequent UTIs, etc.) that would prevent participation in study activities, 8. Presence of severe joint contractures in the affected hand and arm that may interfere with study activities or outcome measures, 9. Severe spasticity, as defined by an Ashworth score of 4 in both sides of the upper limb 10. Pregnancy and breastfeeding (Childbearing potential will be asked at screening, baseline, and every subsequent visit in which the subject would receive transcutaneous spinal cord stimulation whether they could be pregnant. Pregnancy will be ruled out by home over-the-counter urine pregnancy tests for all females of childbearing potential (1) at the time of enrollment and (2) at the beginning of intervention arms. Additional pregnancy tests may be performed if there is concern about pregnancy.) 11. Lack of ability to fully comprehend, cooperate, and/or safely perform study procedures in the investigator's opinion/judgment