Superior semicircular canal dehiscence presenting with recurrent positional vertigo.

Abstract

A 55-year-old man presented to a neuro-otology clinic with a 9-month history of episodic spinning vertigo lasting seconds, triggered by bending forward, lying flat, laughing, or exercising with weights. He noticed fullness in the right ear and unpleasant loudness of his own voice (autophony), without hearing loss or tinnitus. Examination while asymptomatic showed no spontaneous, gaze-evoked or positional nystagmus. Benign paroxysmal positional vertigo (BPPV) was first considered, and he was offered a pair of home video goggles to self-record episodes.1 Three months later, he returned, reporting frequent positional vertigo. Home videos showed paroxysmal rightward torsional down-beating nystagmus on lying supine from the sitting position (latency: 7.2 seconds, duration: 9.4 seconds, peak slow-phase velocity: 10.3°/s; video 1, figure 1, A and B). Sitting up did not produce nystagmus reversal. We hypothesized that this pattern of nystagmus could be provoked by right superior canal (SC) BPPV or unplugging of an SC dehiscence. However, multiple repositioning maneuvers for right SC BPPV/left posterior canal BPPV were conducted without symptom resolution.