NMJ DISORDERS

Neuromuscular junction (NMJ) is a connection between the motor nerve and a muscle. Three main diseases that involve NMJ are Myasthenia Gravis (MG), Lambert-Eaton syndrome (LES), and Botulism. Symptoms include fluctuating muscle weakness that varies in severity, worsens with physical activity, and improves with rest. Most common symptoms include double vision, drooping of eyelid, difficulty chewing or frequent choking, increase in time to finish eating, coughing after swallowing, hoarseness of voice and dysarthria, facial muscle weakness and neck muscle weakness leading to dropped-head syndrome. Involvement of intercostal muscles and diaphragm leads to medical emergency. Precipitants are infections, surgery, immunization, heat, emotional stress, pregnancy, drugs (commonly aminoglycosides, fluoroquinolones, beta-blockers).