A case of Graves' disease associated with ocular myasthenia gravis

Choi, Jun Ho; Noh, Dong Hyo; Park, Byoung Hyun; Jo, Chung Gu

Abstract

Myasthenia gravis and autoimmune thyroid disorders often overlap. It is known that hyperthyroidism occurs in 2~17.5% of patients with myasthenia gravis. Thyrotoxicosis may influence the clinical course of myasthenia gravis. Overlapping clinical features may cause diagnostic confusion when Graves' disease and myasthenia gravis co-exist. Thus, various tests may be needed to distinguish these two diseases. It is clinically important to screen patients with myasthenia gravis for the co-existence of autoimmune thyroid disorders and vice versa. We cared for a patient with Graves' disease associated with ocular myasthenia gravis who presented with fluctuating double vision and ptosis. Ocular myasthenia gravis was diagnosed by electrophysiologic study and presence of acetylcholine receptor antibody. The patient had a favorable clinical and laboratory response to treatment with an anticholinesterase (pyridostigmine) and an antithyroid drug (propylthiouracil), and he had minimal symptoms at the 9-month follow-up examination.