Inclusion Criteria:

• Myelopathy secondary to Progressive MS.
• No clinical or radiologic MS relapses for > 5 years.
• EDSS score of 6.5 (constant bilateral assistance required to walk about 20 meters without resting) as assessed by a Neurologist with a specialty in MS.
• Able to ambulate 10 feet independently with or without gait aid use.
• At least 21 years of age.
• No changes to spasticity medications or dalfampridine over the last 3 months.

Exclusion Criteria:

• Currently a prison inmate, or awaiting trial, related to criminal activity.
• Pregnancy at the time of enrollment.
• History of chronic and/or treatment resistant urinary tract infection.
• Spasticity (grade of 4) measured bilaterally in two muscle groups using Modified Ashworth Scale (MAS). Muscle groups tested will include bilateral knee flexors, extensors; ankle plantarflexors, dorsiflexors.
• Unhealed decubitus ulcer.
• Unhealed skeletal fracture.
• Receiving diathermy treatment.
• Active participation in an interventional clinical trial.
• Any illness or condition which, based on the research team’s assessment, will compromise the patient’s ability to comply with the protocol, patient safety, or the validity of the data collected during this study.
• History of coagulopathy or other significant cardiac or medical risk factors for surgery.
• Ventilator-dependent respiration.
• Diagnosed with cardiopulmonary dysfunction (e.g., chronic obstructive pulmonary disease, cardiac failure, or heart arrhythmia).
• Untreated clinical diagnosis of depression.
• History of frequent hypotension characterized by light headedness, or loss of consciousness.
• History of frequent hypertension characterized by headache, or bradycardia.
• Any active, implanted medical device.
• Treatment of chemodenervation and/or neurolysis during the trial, or within 6 months of initiating the trial.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 4/13/23. Questions regarding updates should be directed to the study team contact.