Delayed vestibulopathy after heat exposure
- 376 Downloads
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.
KeywordsHeat stroke Heat illness Vestibulo-ocular reflex Cerebellum Head impulse test
This study was supported by a grant of the Korea Healthcare Technology R&D Project, Ministry of Health and Welfare, Republic of Korea (HI10C2020).
Compliance with ethical standards
All experiments followed the tenets of the Declaration of Helsinki and this study was approved by the Institutional Review Board of Seoul National University Bundang Hospital (B-B-1603-338-701).
Conflicts of interest
No conflicting relationship exists for the authors.
Drs. Jung, Choi, and H Kim report no disclosure. Dr. Ji-Soo Kim serves as an associate editor of Frontiers in Neuro-otology and on the editorial boards of the Journal of Korean Society of Clinical Neurophysiology, Journal of Clinical Neurology, Frontiers in Neuro-ophthalmology, Journal of Neuro-ophthalmology, Journal of Vestibular Research, Journal of Neurology, and Medicine.
Supplementary material 1 Video 1 Ocular motor findings and ataxia in patient 1. Video shows spontaneous downbeat nystagmus and direction-changing horizontal gaze-evoked nystagmus with a side-pocket-like appearance during lateral gazes. HITs show corrective catch-up saccades during stimulation of horizontal and posterior semicircular canals on both sides with a perverted downward component when stimulating the horizontal canals. Truncal and limb ataxia are also evident (WMV 69513 kb)
Supplementary material 2 Video 2 Horizontal and vertical head impulse tests in patient 2. Video shows horizontal gaze-evoked nystagmus and corrective catch-up saccades during head impulse stimulation of the horizontal and posterior semicircular canals on both sides. Downward corrective saccades are prominent during stimulation of the horizontal canals (WMV 45950 kb)