Signs of reinnervation in myasthenia gravis

In a study of 71 patients with myasthenia gravis, the local fiber density of muscle fibers within motor units was estimated with single fiber electromyography (SFEMG). The fiber density was increased significantly in the patient group, compared to normal controls. This increase was not correlated to disease severity or duration, but was significantly higher in patients treated with cholinesterase inhibitors as compared to untreated patients. The study indicates a slight reorganization of the motor unit in untreated patients with myasthenia gravis and more pronounced changes in patients treated with cholinesterase inhibitors.