Lipoic Acid for Progressive Multiple Sclerosis (MS)

Inclusion Criteria: * Diagnosis of progressive MS as defined by the study * Able to give informed consent and to adhere to study procedures. * Expanded Disability Status Scale (EDSS) 3.0 - 6.5: ambulatory for at least 20 meters without rest and use of bilateral aids (canes, crutches, walker) or better. Exclusion Criteria: * A self-reported medical or neurological problem other than MS that is a cause of progressive or fluctuating gait dysfunction * Unable to undergo MRI * Unable to follow directions in English as standardized scales are not all validated in other languages. * Current major disease or disorder other than MS (e.g., cancer, renal disease, end-stage cardiopulmonary disease, post-traumatic stress disorder, etc.) that may interfere with study procedures. Note: Stable abnormal laboratory values of no more than Grade 1 determined to not be of clinical significance to the primary treating physician for that condition may be permitted per local site investigator discretion. * Pregnant or breast-feeding. * Insulin-dependent diabetes or diabetes not controlled on oral diabetes medications. * Scheduled (every 3 months or more frequently) IV or oral steroids in the year prior to enrolment. * IV or oral steroids in the 60 days prior to enrolment. * Use of LA in the prior 2 years exceeding the equivalent of 1200mg daily for 3 months. * Participation in the pilot LA in SPMS trial.