Selective vestibular neurolabyrinthitis of the lateral and superior semicircular canal ampulla and ampullary nerves.

Objectives: The diagnosis of vestibular neurolabyrinthitis is based on the sudden appearance of vertigo that lasts for hours or days without associated cochlear or central nervous system signs or symptoms. The advent of the video head impulse test, cervical vestibular evoked myogenic potential testing, and ocular vestibular evoked myogenic potential testing has provided interesting clinical evidence for evaluating and monitoring the damage to specific compartments of the vestibular apparatus. These various methods of testing individual end-organ functions may have a clinical impact on the vestibular workup of neurolabyrinthitis. Methods: This report describes 3 patients with acute vestibular neurolabyrinthitis in whom caloric tests, cervical vestibular evoked myogenic potentials, ocular vestibular evoked myogenic potentials, and the video head impulse test led to a suspicion of peripheral vestibular deficits of the lateral or superior semicircular canal ampulla or ampullary nerves. Results: In our patients, the examination results (normal hearing, absence of responses on caloric testing, and bilateral preservation of cervical and ocular vestibular evoked myogenic potentials) disclosed an acute partial superior vestibular neurolabyrinthitis. Conclusions: 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.