Patients with vestibular loss, tullio phenomenon, and pressure-induced nystagmus: vestibular atelectasis?

OBJECTIVE To propose an etiology for a syndrome of bilateral vestibular hypofunction and sound and/or pressure-evoked eye movements with normal hearing thresholds. DESIGN Retrospective case series. SETTING Tertiary care referral center. PATIENTS Four patients with bilateral vestibular hypofunction, sound and/or pressure-evoked nystagmus and normal hearing thresholds were identified over a 3-year period. No evidence of other known vestibular disorders was identified. None of these patients presented with a history of exposure to toxins, radiation, aminoglycosides or chemotherapy; head trauma; or a family history of inherited vestibular loss. MAIN OUTCOME MEASURE All patients underwent high-resolution CT scan of the temporal bones to evaluate for labyrinthine dehiscence. Additionally, all individuals underwent audiometric testing to ANSI standards, vestibular-evoked myogenic potentials (VEMP) testing using either click stimulus cervical VEMPs (cVEMPs), or tone burst ocular VEMPs (oVEMPs). Bithermal caloric stimulation was used to measure horizontal semicircular canal function, with either videonystagmography (VNG) or electronystagmography (ENG) to record eye movements. Individual responses of each of the 6 semicircular canals (SCC) to rapid head rotations were tested with the bedside head impulse test. RESULTS We identified 4 patients with a combination of bilateral vestibular hypofunction and sound and/or pressure-induced eye movements, normal-hearing thresholds and no evidence for any other vestibular disorder. CONCLUSION We suggest that this unique combination of symptoms should be considered as the clinical presentation of vestibular atelectasis, which has been previously described histologically as collapse of the endolymph-containing portions of the labyrinth.