Bilateral pseudo-internuclear ophthalmoplegia in myasthenia gravis.
A 38-year-old male with bilateral pseudo-internuclear ophthalmoplegia (-INO) in myasthenia that could have been misdiagnosed as INO in multiple sclerosis is reported. He experienced fluctuating symptoms including double vision, imbalance, and tinnitus. His eye movements simulated bilateral INO, with a downshoot in abduction. After thymectomy, his eye movements became normal. From our case and a review of the literature, we propose that ptosis, downshoot, and fatigability are likely to be signs of pseudo-INO in myasthenia, whereas an impaired vertical smooth pursuit is unlikely. Dissociated nystagmus and monocular overshoot might be the results of central compensation.
Ito
K
K
Department of Otolaryngology, University of Tokyo, Bunkyo-ku, Japan. itoken-tky@umin.u-tokyo.ac.jp
Mizutani
J
J
Murofushi
T
T
Mizuno
M
M
D000328:Adult; D004172:Diplopia / Q000209:etiology; D004584:Electronystagmography; D005133:Eye Movements; D006801:Humans; D008297:Male; D009157:Myasthenia Gravis / Q000150:complications* / Q000601:surgery; D009886:Ophthalmoplegia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013934:Thymectomy; D014012:Tinnitus / Q000209:etiology