Intravenous steroid treatment is the first line of therapy often used in acute TM. Corticosteroids have multiple mechanisms of action including anti-inflammatory activity, immunosuppressive properties, and antiproliferative actions. Though there is no randomized double-blind placebo-controlled study that supports this approach, evidence from related disorders and clinical experience support this treatment. At the Johns Hopkins TM Center, the standard of care includes intravenous methylprednisolone (1000 mg) or dexamethasone (200 mg) for 3 to 5 days unless there are compelling reasons to avoid this therapy. The decision to offer continued steroids or to add a new treatment is often based on the clinical course and MRI appearance at the end of 5 days of steroids.
PLASMA EXCHANGE (PLEX)
PLEX is often initiated in moderate to severe TM (i.e., inability to walk, markedly impaired autonomic function, and sensory loss in the lower extremities) in individuals who show little clinical improvement after instituting 5 to 7 days of intravenous steroids, but may also be initiated at first presentation. PLEX is believed to work in autoimmune CNS diseases through the removal of specific or nonspecific soluble factors likely to mediate, be responsible for, or contribute to inflammatory-mediated target organ damage. PLEX has been shown to be effective in adults with TM and other inflammatory disorders of the CNS.
OTHER IMMUNOMODULATORY TREATMENT
If there is continued progression despite intravenous steroid therapy and PLEX, pulse dose intravenous cyclophosphamide (800–1000 mg/m2) is considered. Cyclophosphamide is known to have immunosuppressive properties. From the Johns Hopkins TM Center experience, it has been reported that PLEX provided an added benefit to steroids in patients who were not at a disability level of ASIA A and who did not have a history of autoimmune disease. For those who were classified at a disability level of ASIA A at their nadir, they showed a significant benefit when given combination therapy with steroids, PLEX and IV cyclophosphamide. Cyclophosphamide should be administered under the supervision of an experienced oncology team, and caregivers should monitor the patient carefully for hemorrhagic cystitis and cytopenias.
Chronic immunomodulatory therapy should be considered for recurrent TM. The ideal treatment regimen is not known and it is important for your neurologist to consult with a specialist who has significant experience in treating these rare, recurrent neuroimmunologic disorders.