SELECTIVE VESTIBULAR NEUROLABYRINTHITIS OF THE LATERAL AND SUPERIOR SEMICIRCULAR CANAL AMPULLA AND AMPULLARY NERVES.

Objective: The diagnosis of vestibular neurolabyrinthitis is based on the sudden appearance of vertigo lasting for hours or days without associated cochlear or central nervous system signs or symptoms. The advent of the video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (C-VEMPs) and ocular vestibular evoked myogenic potentials (O-VEMPs) has provided interesting clinical evidence for evaluating and monitoring the damage to specific compartments of the vestibular apparatus. These various modality of testing individual end-organ function may have a clinical impact on vestibular workup of the neurolabyrinthitis. Patients and Methods: This report describes three patients with acute vestibular neurolabyrinthitis in whom caloric tests, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs) and the head impulse test (vHIT) led to a suspicion of peripheral vestibular deficits of the lateral or superior semicircular canals ampulla or ampullary nerves. Conclusion: To our knowledge, these are the first reported cases in which selective damage to the lateral and superior semicircular canals and their nerves caused by neurolabyrinthitis was demonstrated clinically. Our clinical results indicate that the damage can be selective for specific vestibular end organs.