Bilateral dehiscence of the bony cochlear basal turn.

OBJECTIVE

To identify bony labyrinth defects as causing symptoms that might otherwise be difficult to understand.

DESIGN

Imaging investigation on cases of lowered vestibular evoked myogenic potentials (VEMP) threshold.

SETTING

Academic tertiary case-referral medical center.

PATIENTS: One patient with continuous bilateral tinnitus.

INTERVENTIONS: High-resolution computed tomography of petrous bone was performed after audiometry, impedance, and VEMP recording.

RESULTS

We found a previously unreported dehiscence of the bony plate between the basal turn of the cochlea and the carotid canal.

CONCLUSIONS

A VEMP study could prompt diagnostic imaging tests that might otherwise be neglected. Moreover, it is important to consider the possibility of a bony dehiscence involving not just the semicircular canals.