Snapshot A 62-year-old man presents to his primary care physician for "seeing double." He reports that he has been experiencing these symptoms for a few months. His diplopia is worse after reading a book or watching television. He says that at times he notices his left eyelid "droops" at the end of the day and improves after waking up from sleep. He notes episodes of fluctuating weakness when chewing harder foods. On physical examination, there is left-sided ptosis. Pupillary reflex is intact. A plastic glove with ice is applied on the ptosis for approximately 2 minutes and the ptosis markedly improves. Serology is positive for anti-acetylcholine receptor antibodies and preparations are made for a computerized tomography scan of the chest. Introduction Clinical definition login to view 1 more bullet Associated conditions login to view 2 more bullets Epidemiology Incidence login to view 2 more bullets Risk factors login to view 4 more bullets Pathogenesis Autoantibodies directed against a protein of the neuromuscular junction login to view 5 more bullets T-cells play a role as well login to view 1 more bullet Presentation Symptoms login to view 15 more bullets Physical exam login to view 10 more bullets Imaging Computerized tomography (CT) scan login to view 4 more bullets Studies Labs login to view 4 more bullets Electromyogram (EMG) login to view 1 more bullet Differential Lambert-Eaton myasthenic syndrome (LEMS) login to view 3 more bullets Botulism login to view 2 more bullets Thyroid ophthalmopathy Treatment Medical login to view 15 more bullets Procedural login to view 3 more bullets Surgical login to view 4 more bullets Complications Myasthenic crisis login to view 1 more bullet Prognosis Most patients with ocular involvement progress to generalized myasthenia gravis