Myasthenia gravis masquerading as post-poliomyelitis syndrome.

A 79-year-old man with previous bulbar poliomyelitis developed dysphagia and was diagnosed as having post-polio syndrome. Over 2 years, his swallowing deteriorated and he suffered an aspiration pneumonia. Only after the subsequent development of fatigue and facial weakness was myasthenia gravis diagnosed. Diagnostic criteria for post-polio syndrome include the exclusion of all other neurological conditions such as myasthenia gravis. Moreover, in any instance where a patient develops new symptoms, it is advisable to reconsider the original diagnosis.