Objective: To confirm the origin and pathway of vestibular evoked myogenic
potentials (VEMPs) in humans.
Design: Case study.
Setting: University hospital.
Patients: A patient with a narrow internal auditory meatus (IAM).
Main Outcome Measures: Imaging studies and functional studies concerning th
e seventh and eighth cranial nerves.
Results: Of the 4 nerves in the IAM, all but the cochlear nerve had normal
function and normal courses, despite the pronounced narrowing of the IAM. T
he facial nerve had a normal diameter, but the vestibular nerves were thinn
er. Imaging revealed that the cochlear nerve was absent or extremely thinne
d. Both the cochlea and the cochlear nerve showed no function in the affect
ed ear, although the VEMPs were evoked normally.
Conclusion: Our results definitively support the vestibular origin of VEMPs