Horizontal Direction-Changing Positional Nystagmus and Vertigo: A Case of Vestibular Migraine Masquerading as Horizontal Canal BPPV.

Episodic positional vertigo is typically due to benign paroxysmal positional vertigo (BPPV) but may also be a manifestation of vestibular migraine. Distinguishing vestibular migraine from BPPV is essential since the treatment of each disorder is markedly different. The 31-month clinical course of a 41-year-old woman with vestibular migraine causing recurrent positional vertigo is described. During vestibular migraine attacks, she developed left-beating nystagmus in the upright position with removal of fixation, and geotropic horizontal nystagmus during the supine roll test. Interictally, her exam demonstrated positional apogeotropic horizontal nystagmus with the supine roll test, more intense in the supine head left position. Her vestibular migraine was successfully controlled with topiramate and eletriptan.