Pseudo-internuclear ophthalmoplegia as a sign of overlapping myasthenia gravis in a patient with 'intractable' hypothyroidism.
We describe a 52-year-old man with a history of increasing fatigability and gait disturbances that were first attributed to hypothyroidism. On examination, he had bilateral pseudo-internuclear ophthalmoplegia with weakness of adduction and abducting nystagmus. Convergence was also impaired and he showed proximal weakness of the limb. Intravenous edrophonium almost completely abolished the nystagmus and adducting muscle weakness, and improved the strength of proximal muscles groups. The clinical response to the administration of edrophonium, the presence of AChR binding antibodes and the repetitive nerve stimulation test findings indicated that the patient had pseudo-internuclear ophthalmoplegia as a manifestation of generalized myasthenia gravis. Whereas hypothyroidism was effectively controlled with levothyroxine, his subsequent response to thymectomy, prednisolone and cholinesterase inhibitors confirmed the diagnosis of generalized myasthenia gravis.
Yamazaki
Yuu
Y
Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan. yuu.yamazaki@gmail.com
Sugiura
Tomohito
T
Kurokawa
Katsumi
K
D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D004491:Edrophonium; D006801:Humans; D007037:Hypothyroidism / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D009759:Nystagmus, Pathologic / Q000209:etiology*; D015835:Ocular Motility Disorders / Q000209:etiology*; D011239:Prednisolone / Q000627:therapeutic use
D000893:Anti-Inflammatory Agents; D002800:Cholinesterase Inhibitors; D004491:Edrophonium; D011239:Prednisolone