Myasthenia gravis. Diagnostic methods and control measures for a chronic disease.

Myasthenia gravis should be entertained as a possible diagnosis in any patient who presents with muscle weakness or visual disturbance. The most common symptom is exacerbation of muscle fatigue with repeated use of the muscle and improvement with rest. Several inexpensive diagnostic tests for myasthenia gravis that can be performed by primary care physicians are available. Standard therapy in most cases is early thymectomy, followed by a highly individualized medication program that usually includes the anticholinesterase drug pyridostigmine bromide (Mestinon, Regonol). Corticosteroids and other immunosuppressive agents (usually azathioprine [Imuran]) may be added or substituted if response to anticholinesterase therapy is inadequate. Although myasthenia gravis is a chronic disease, it can be well controlled in most patients, provided they comply with treatment. Patient education is therefore essential.