A 59-year-old man presented to our neuroendovascular clinic with a 10-month history of chronic dizziness, described as a spinning sensation, with associated gait instability and blurred vision upon head rotation. On examination, the spinning sensation could be elicited with mostly leftward head rotation. When the patient turned his head to a more neutral position, the symptoms slowly subsided. Flexion or extension of the neck did not elicit vertigo. The Dix--Hallpike manoeuvre did not elicit nystagmus and a Romberg test was negative. We did not observe any other neurologic abnormalities.
We initially thought the patient had benign paroxysmal positional vertigo; however, the Epley manoeuvres, vestibular rehabilitation therapy and meclizine were ineffective.
Given the refractory nature of the patient's vertigo, lack of a clear diagnosis and persistent ability to elicit symptoms with head rotation, we ordered cerebral angiography, which showed focal 80% narrowing of the left vertebral artery with...