Abducens neuromyotonia due to internal carotid artery aneurysm.
Ocular neuromyotonia refers to paroxysmal involuntary contraction of one or more ocular muscles resulting in paroxysmal diplopia and strabismus. A 73-year-old woman reported spells of horizontal diplopia that usually developed after leftward gaze and mostly lasted less than one minute. Between the episodes, the extraocular movements were normal without aberrant regeneration. The diplopic paroxysms could be triggered by leftward gaze for several seconds. During the episode, the left eye was exotropic with mild adduction limitation. Brain imaging revealed an aneurysm in the left internal carotid artery. The episodes resolved with carbamazepine. Aneurysm of the internal carotid artery is a rare cause of abducens neuromyotonia. A compressive lesion may give rise to ocular neuromyotonia even in the absence of prior irradiation.
Park
Hee Young
HY
Department of Neurology, College of Medicine, Ajou University, Suwon, Republic of Korea.
Hwang
Jeong-Min
JM
Kim
Ji Soo
JS
D000368:Aged; D002340:Carotid Artery Diseases / Q000150:complications* / Q000473:pathology; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D020386:Isaacs Syndrome / Q000209:etiology* / Q000473:pathology; D008279:Magnetic Resonance Imaging