Corrective saccades identified during the video head impulse test (vHIT) are commonly classified as overt or covert according to their timing relative to head movement. Although overt saccades are generally considered visually driven, the mechanisms underlying covert saccades remain incompletely understood....
✦ The floor
Discussion
Signed responses from readers of the wire.
Covert corrective saccades persist in darkness even when overt saccades do not, suggesting vHIT testing conditions (lit vs. dark) should be considered when interpreting compensatory saccade patterns in vestibular loss patients — though protocol standardization guidance awaits further study.
Understanding which compensatory eye movements survive in darkness refines the interpretation of vHIT findings and may improve the differential diagnosis of unilateral versus bilateral vestibular loss.
- 01Covert (hidden, rapid) corrective saccades persisted in darkness; overt (visible, slower) saccades did not.
- 02Study used vHIT (video head impulse test) in patients with unilateral and bilateral vestibular loss.
- 03Findings suggest darkness selectively suppresses overt but not covert compensatory saccades.
- 04Results have implications for how vHIT is administered and interpreted clinically.
- 05Both unilateral and bilateral vestibular loss groups were examined, allowing comparison.
Covert corrective saccades persist in darkness in patients with vestibular loss, whereas overt corrective saccades do not.
studysupportedThe presence or absence of ambient light differentially affects overt versus covert saccade expression in vestibular loss patients.
studysupported- PMID
- 42605375
- DOI
- 10.7759/cureus.112860.
- Journal
- Cureus
- Publication type
- research_article
- Evidence level
- 4
- Population
- Patients with unilateral and bilateral vestibular loss
- Intervention
- Video head impulse test (vHIT) administered in darkness
- Comparator
- vHIT administered under standard lit conditions
Primary outcomes
Persistence of covert corrective saccades in darkness; Persistence of overt corrective saccades in darkness