Severe, focal tibialis anterior and triceps brachii weakness in myasthenia gravis: a case report.

We report a case of a patient with myasthenia gravis who presented with an atypically focal distribution of severe weakness in the triceps brachii and tibialis anterior muscles. Repetitive nerve stimulation studies demonstrated the typical decrement at rest, but also demonstrated marked facilitation after brief exercise. This case adds to the clinical and electrophysiological spectrum of variations of presentation of myasthenia gravis.