Eyes, Ears, Nose and Throatcommon
A 38-year-old woman experiences brief episodes of spinning when she rolls over in bed or looks upward. Each episode lasts less than a minute, and she is well between attacks. She has no hearing loss, tinnitus, headache or neurological symptoms. Dix–Hallpike testing on the right produces vertigo and a characteristic positional nystagmus after a short delay. Which diagnosis best explains the presentation?