Oculopharyngeal muscular dystrophy as a cause of progression of weakness in antibody positive myasthenia gravis

AChR-seropositive myasthenia gravis in muscular dystrophy: diagnostic pitfalls and clinical management challenges

The co-occurrence of genetic myopathies with myasthenia gravis (MG) is extremely rare, however a few studies have been reported. We aim to explore the link between genetically inherited muscle disorders and immune-mediated neuromuscular junction conditions, taking into account the diagnostic and therapeutic implications posed by these combined conditions. We searched all English medical papers registered in Web of Knowledge, PubMed, Google Scholar, and Science Direct between January 1987 concerning the association between muscular dystrophies (MD) and MG, also adding three new cases to the series reported so far. Three new clinical cases in which MG concurs with oculopharyngeal muscular dystrophy (OPMD) or facioscapulohumeral muscular dystrophy (FSHD) or myotonic dystrophy type 2 (DM2) were reported. A comprehensive literature review showed that FSHD is the dystrophy most frequently associated with generalized MG. The AChR antibody titer is high and neurophysiologic tests prove to be an essential tool for the diagnosis. The association between MG and MD is rare but should not be underestimated. The presence of unusual clinical features suggest investigating additional overlapping condition, especially when a treatable disease like MG is suspected.

Oculopharyngeal muscular dystrophy, myasthenia gravis, systemic lupus erythematosus: overlap and interactions

Ptosis and proximal weakness may develop in multiple diseases including oculopharyngeal muscular dystrophy (OPMD) and myasthenia gravis (MG). These two entities can be challenging to differentiate since they may have important clinical and neurophysiological overlap. Systemic lupus erythematosus (SLE), a common autoimmune disease, has been described in association with MG.We present a woman in her 60s with fluctuating bilateral ptosis and proximal muscle weakness. Single fibre electromyography showed increased jitter. Her brother has genetically proven OPMD. The investigation revealed a positive genetic test for OPMD and positive antibodies for acetylcholine receptor. Additionally, she has SLE, treated with hydroxychloroquine for more than 30 years.This case highlights the importance of a thoughtful anamnesis with personal and familial history and raises awareness for the rare coexistence of three pathologies with some common clinical characteristics but different treatments and management.