A Pilot Study of Lithium in Progressive Multiple Sclerosis

Inclusion Criteria: * Diagnosis of a progressive subtype of multiple sclerosis by revised 2005 McDonald Criteria. * EDSS of 3.0-6.5 * Ages 30-65 * Must be mentally capable of providing informed consent and following study guidelines. Exclusion Criteria: * Relapse or steroid treatment within 1 month of trial entry. * Any current or previous treatment with mitoxantrone, azathioprine, methotrexate, mycophenolate, cyclophosphamide, or any experimental therapy. * Women who are pregnant, wishing to become pregnant in the coming 30 months, or are breastfeeding. * Sexually active women unwilling to use reliable contraception (oral contraceptives, condom, IUD). * Patients with known kidney dysfunction or creatinine \>1.4; known cardiac arrhythmia or significant conduction abnormality on EKG; uncontrolled thyroid disease or TSH \>20% above the upper limit of normal; uncontrolled psoriasis, HIV, or any other severe medical condition. * Patients with a history of unstable psychiatric illness or active severe depression. * Patients with a history of seizure. * Concurrent use of any of the following medications: Antipsychotics, diuretics, digoxin, or iodide salts. * Use of non-steroidal anti-inflammatory drugs (NSAIDs) 5 or more days a week. * Patients with a history of substance abuse in the past year. * Patients sensitive to gadolinium, or who are unable to undergo the required number of MRI scans. * Unable to speak or understand sufficient English to consent or complete study procedures. * Patients unable or unwilling to provide informed consent.