Labyrinthitis and Vestibular Neuritis

Vestibular neuritis and labyrinthitis are acute peripheral disorders affecting the eighth cranial nerve. Vestibular neuritis involves the vestibular division, so the patient develops a sudden loss of vestibular input without hearing loss or tinnitus. Labyrinthitis also involves the cochlear portion, adding auditory symptoms. The mechanism explains the dramatic presentation. When one vestibular apparatus suddenly becomes less active, the brain receives unequal signals from the two sides. That mismatch is interpreted as movement even when the patient is still, producing sustained vertigo, spontaneous nystagmus, nausea, vomiting, and difficulty walking. Over time, the vestibular nuclei, cerebellum, and cortex recalibrate to the new baseline; this central compensation is why mobility and gaze stability improve with appropriate activity and rehabilitation. The useful bedside distinction is simple but not sufficient by itself: vestibular neuritis preserves hearing, while labyrinthitis does not. Hearing loss, however, must never be used as reassurance that the process is peripheral. Anterior inferior cerebellar artery infarction can also produce vertigo, nystagmus, and acute hearing loss.