To the Editor.
—Drs Husain and coworkers1 described a patient who began to have limb weakness in ado-lescence. He did not have symptoms referable to cranial muscles until 20 years after onset. Then he had a respiratory crisis that was apparently followed by chronic alveolar hypoventilation.As the authors indicate, there was no question about the diagnosis of myasthenia gravis in that case. The anatomic distribution of affected muscles and the characteristic decremental response of muscle to repetitive stimulation of nerves suffice for that diagnosis. Unfortunately, an edrophonium test was not done, but the patient did respond to oral treatment with neostigmine and pyridostigmine. There were no antibodies to acetylcholine receptor, but that is not required for diagnosis.The authors concluded that, in addition to myasthenia gravis, the patient had "limb-girdle muscular dystrophy." The dual diagnosis was based on 20 years of weakness limited to limb muscles, and