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Published on: August 28, 2019
Gentamicin vestibulotoxicity impairs human electrically evoked vestibulo-ocular reflex
1Central Clinical School, Faculty of Medicine, University of Sydney, and Institute of Clinical Neuroscience, Royal Prince Alfred Hospital, Sydney, Australia. sweea@icn.usyd.edu.au
Neurology
|November 26, 2008
Summary
Gentamicin-induced vestibulotoxicity impairs the electrically evoked vestibulo-ocular reflex (eVOR), particularly its phasic component. This eVOR dysfunction may serve as a marker for vestibular hair cell damage.
Area of Science:
- Neuroscience
- Ophthalmology
- Otolaryngology
Background:
- Electrical vestibular stimulation activates vestibular afferents to mediate the electrically evoked vestibulo-ocular reflex (eVOR).
- Gentamicin (an antibiotic) causes vestibulotoxicity through hair cell damage and death.
Purpose of the Study:
- To investigate if human eVOR is impaired by gentamicin-induced vestibulotoxicity (GV).
- To assess the role of vestibular hair cells in mediating eVOR.
Main Methods:
- Recorded three-dimensional binocular eye movements using dual-search coils.
- Stimulated subjects with bilateral, bipolar, 100 msec direct current-steps at varying intensities (0.9–10.0 mA).
- Compared eVOR in 12 GV patients and 13 healthy subjects.
Main Results:
- Normal eVOR exhibited a predominantly torsional response with distinct phasic and tonic components.
- Gentamicin vestibulotoxicity (GV) significantly impaired the phasic eVOR component, increasing its latency.
- Phasic eVOR was more affected than tonic eVOR in GV patients, with severity correlating to hair cell damage.
Conclusions:
- Impairment of eVOR in GV suggests vestibular hair cells mediate this reflex.
- Abnormalities in the phasic eVOR component may indicate vestibular injury from gentamicin exposure.
- eVOR assessment could be a valuable tool for diagnosing and monitoring vestibulotoxicity.
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