Management/Treatment of Lambert-Eaton Myasthenic Syndrome

This article reviews the current treatment strategies for patients with Lambert-Eaton myasthenic syndrome (LEMS) including potassium channel blockers, immunosuppressant therapies, and management of dysautonomia. Since the first report in 1983, 3,4-diaminopyridine (amifampridine) has been used as a symptomatic treatment for LEMS. The biggest recent development in LEMS treatment is the approval of two amifampridine drugs in 2018 by the Food and Drug Administration (FDA). Amifampridine phosphate (Firdapse®) is a salt form that was approved for adult patients with LEMS. Amifampridine (Ruzurgi®) was approved for children aged 6 to 17 years old. The primary treatment option for LEMS remains amifampridine, and the efficacy of both FDA-approved formulations has been demonstrated in high-quality clinical trials. Other immunosuppressant treatments, such as corticosteroids, azathioprine, mycophenolate mofetil, and rituximab, can be used when amifampridine is unavailable, are contraindicated, or do not fully control patient symptoms. For the management of acute exacerbations or severe disease, IVIg or plasma exchange can be considered. High-quality evidence supporting the use of immunosuppressive and immunomodulatory treatments in LEMS patients is generally lacking. Treatment response can be monitored by bedside exams and the Triple Timed Up-and-Go test.