EMG evidence of myopathy and the occurrence of titin autoantibodies in patients with myasthenia gravis

We studied 65 patients with myasthenia gravis (MG). Clinical, neurophysiolo gical, immunological, and histological findings suggested the coexistence o f a presumed autoimmune myopathy. The clinical features were persistent pyr idostigmine-resistant weakness and atrophy of striated muscles. The myopath y was found more often in patients with late-onset MG than in those with ea rly-onset (37% vs 13%). Patients with myopathy were also prone to have othe r immune disorders (47% vs 13%). Elevated titres of antibodies against titi n were detected more often in patients with electromyography (EMG) evidence of myopathy than in the sera of those without, and only in late-onset MG c ases. Eur J Neurol 6:555-563 (C) 1999 Lippincott Williams & Wilkins.