Chronic Myopathy Associated With Anti–Signal Recognition Particle Antibodies Can Be Misdiagnosed As Facioscapulohumeral Muscular Dystrophy. Issue 4 (June 2016)

• Record Type: Journal Article
• Authors: Ikeda, Kensuke; Mori-Yoshimura, Madoka; Yamamoto, Toshiyuki; Sonoo, Masahiro; Suzuki, Shigeaki; Kondo, Yoshiyuki; Nakamura, Harumasa; Mitsuhashi, Kana; Maeda, Meiko Hashimoto; Shimizu, Jun; Hayashi, Yukiko K.; Nishino, Ichizo; Oya, Yasushi; Murata, Miho
• Is Part Of: Journal of clinical neuromuscular disease. Volume 17:Issue 4(2016:Jun.)
• Publication Date: 2016-06
• Subjects: anti–signal recognition particle antibody -- facioscapulohumeral muscular dystrophy -- dysphagia -- winged scapulae; Neuromuscular diseases -- Periodicals; 616.744005
• DOI: 10.1097/CND.0000000000000115
• Languages: English
• ISSNs: 1522-0443

Abstract

Abstract: Objectives: To report cases of chronic autoimmune necrotizing myopathy with anti–signal recognition particle antibodies (anti-SRP myopathy) initially misdiagnosed as muscular dystrophy, in particular, facioscapulohumeral muscular dystrophy (FSHD). Methods: Medical records of patients with anti-SRP myopathy in our institution were retrospectively reviewed. Results: All 6 patients were initially diagnosed with muscular dystrophy because of the long-term clinical course and lack of inflammation on biopsy; 5 were diagnosed with FSHD based on a winged scapula. However, the following features suggested an alternative diagnosis, leading to anti-SRP antibody measurement: (1) lack of family history, (2) lack of facial involvement and asymmetry, (3) prominent dysphagia, and (4) profuse spontaneous activities on needle electromyography. All patients showed improvement with immunomodulating therapy. Conclusions: Anti-SRP antibody measurement should be considered in patients diagnosed with FSHD if they present with diagnostic hallmarks of anti-SRP myopathy listed above, to avoid oversight of this potentially treatable disorder.