Objectives: We report, with neuro-otologic findings, a very rare case of a large jugular bulb diverticulum eroding the internal auditory canal (IAC).
Methods: We present the imaging and functional studies of a 29-year-old woman in whom a large jugular bulb diverticulum on the left side was found incidentally.
Results: Imaging studies revealed a normal external auditory canal, middle ear, and inner ear, but a large jugular bulb diverticulum extending superiorly on the left side had eroded the IAC from below and behind with destruction of the petrous bone. Caloric responses and facial movements were normal. Vestibular evoked myogenic potentials with bone conduction stimuli were absent on the left, indicating dysfunction of the left inferior vestibular system.
Conclusions: This is the first report in the English-language literature of detailed imaging and functional findings in a very large diverticulum invading the IAC. Vestibular evoked myogenic potentials were useful in uncovering subclinical inferior vestibular system dysfunction in the jugular bulb diverticulum invading the IAC.