Ocular Myastheia Gravis as the First Presentation of Myastheia Gravis: A Case Report

Abstract

Abstract Background Myasthenia gravis (MG) is a rare and potentially dangerous autoimmune neuromuscular disease, which affects the acetylcholine receptors at the neuromuscular junction of skeletal muscle. lt is characterized by fluctuating weakness and fatigue of the ocular, bulbar, limb, and respiratory muscles and initial symptoms are usually ptosis and diplopia. Over half of patients with MG will initially experience isolated ocular symptoms in one eye or both eyes, which are called ocular myasthenia gravis (OMG). OMG’s diverse symptoms may readily masquerade as other neurological conditions, posing a diagnostic challenge to clinicians. Case presentation: A 49-year-old female presented to the Emergency Department with a seven-day history of unilateral persistent ptosis with inflexible eye movement, concerning for oculomotor nerve paralysis initially. However, cranial CTA found no evidence of stroke or any other central etiology. Routine laboratory testing was unremarkable. Neurology was consulted and neurologist recommended sending tensilon testing (pharmacologically induced improvement in symptoms using the anticholinesterase inhibitor) and electromyographic testing. At the patient’s subsequent hospitalization in neurology department, these tests were found to be abnormal. The patient underwent complete ophthalmic examination and medical history review, was diagnosed of ocular myasthenia gravis (OMG) eventually. The patient subsequently underwent hormone and immunosuppressive therapy with obvious improvement in her symptoms. Conclusions MG may present as unilateral ptosis or diplopia with the hallmark characteristic of fluctuating muscle weakness. Early diagnosis and subsequent treatment of MG improve long term prognosis and remission rates. Prednisone is the most commonly used immune modulator for the treatment of MG. Emergency physicians should consider myasthenia gravis in cases of ocular symptoms after ruling-out emergent central etiologies.