Delayed vestibulopathy after heat exposure.

Even though dizziness is a common symptom of heat illness, comprehensive evaluation of the vestibular function has not been available in this potentially life-threatening disorder. Three patients developed vertigo about a week after heat exposure. Evaluation showed bilateral impairments of the vestibulo-ocular reflex during head impulses and the signs of vestibulocerebellar dysfunction that included spontaneous downbeat nystagmus, gaze-evoked nystagmus, and positional downbeat nystagmus. Exposure to excessive heat may give rise to delayed vestibulopathy by damaging the vestibulocerebellum.