Teaching Video NeuroImages: Bilateral abducens ocular neuromyotonia

A 44-year-old woman with a history of resolved nasopharyngeal carcinoma presented with an 8-month history of transient binocular horizontal diplopia. She received complete concurrent chemoradiotherapy 7 years ago. Following prolonged eccentric gaze to the right, she developed involuntary contraction of right lateral rectus, which resulted in 60 seconds of right exotropia. These events also occurred following prolonged eccentric gaze to the left, which resulted in left exotropia (video 1 at Neurology.org). Treatment with carbamazepine improved her symptoms (video 2). Ocular neuromyotonia should be included as a differential diagnosis of transient diplopia, especially in those who have undergone prior radiotherapy to the parasellar region.1
Source: Neurology - Category: Neurology Authors: Tags: All Neuro-ophthalmology, Diplopia (double vision) RESIDENT AND FELLOW SECTION Source Type: research