Clinical findings in MuSK-antibody positive myasthenia gravis: A U.S. experience

✍ Scribed by Mamatha Pasnoor; Gil I. Wolfe; Sharon Nations; Jaya Trivedi; Richard J. Barohn; Laura Herbelin; April McVey; Mazen Dimachkie; John Kissel; Ronan Walsh; Anthony Amato; Tahseen Mozaffar; Marcel Hungs; Luis Chui; Jonathan Goldstein; Steven Novella; Ted Burns; Lawrence Phillips; Gwendolyn Claussen; Angela Young; Tulio Bertorini; Shin Oh

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 104 KB
• Volume: 41
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/mus.21533

✦ Synopsis

Abstract

We performed a retrospective chart review on 53 muscle‐specific kinase antibody (MuSK‐Ab)‐positive myasthenia gravis (MG) patients at nine university‐based centers in the U.S. Of these, 66% were Caucasian, 85% were women, and age of onset was 9–79 years. Twenty‐seven patients were nonresponsive to anticholinesterase therapy. Myasthenia Gravis Foundation of America improvement status was achieved in 53% patients on corticosteroids, 51% with plasma exchange, and in 20% on intravenous immunoglobulin (IVIG). Thymectomy was beneficial in 7/18 patients at 3 years. Long‐term (≥3 years) outcome was very favorable in 58% of patients who achieved remission and/or minimal manifestation status. Overall, 73% improved. There was one MG‐related death. This survey reinforces several cardinal features of MuSK‐Ab‐positive MG, including prominent bulbar involvement and anticholinesterase nonresponsiveness. Facial or tongue atrophy was rare. Most patients respond favorably to immunotherapy. The best clinical response was to corticosteroids and plasma exchange, and the poorest response was to IVIG. Long‐term outcome is favorable in about 60% of cases. Muscle Nerve, 2009