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Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
Published on: April 18, 2019
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Effect of different head impulse procedures on vestibulo-ocular reflex gain
1Audiovestibular medicine, OtoRhinolaryngology department Alexandria University, Egypt.
Acta Otorrinolaringologica Espanola
|July 23, 2021
Summary
The starting head position does not impact vestibulo-ocular reflex (VOR) gain. Both video head impulse test (vHIT) and Suppression Head impulse test (SHIMP) showed consistent VOR gain regardless of head impulse direction.
Area of Science:
- Vestibular Neuroscience
- Ophthalmology
- Neurology
Background:
- The vestibulo-ocular reflex (VOR) stabilizes gaze during head movements.
- Accurate VOR gain measurement is crucial for diagnosing vestibular disorders.
- The influence of head impulse direction on VOR gain in clinical tests is not fully understood.
Purpose of the Study:
- To investigate the effect of head impulse direction (outward vs. inward) on VOR gain.
- To compare VOR gain measurements using the video head impulse test (vHIT) and the Suppression Head impulse test (SHIMP).
Main Methods:
- Twenty healthy subjects underwent vHIT and SHIMP in the lateral plane.
- Both outward and inward head impulses were applied (ten per side).
- VOR gain was statistically compared between outward and inward impulses for both tests.
Main Results:
- No statistically significant difference in VOR gain was found between outward and inward head impulses for either vHIT or SHIMP.
- This held true for both the right and left lateral semicircular canals.
- No significant difference in VOR gain was observed between the right and left semicircular canals.
Conclusions:
- The initial head position (outward vs. inward) does not influence VOR gain measurements.
- vHIT and SHIMP provide reliable VOR gain assessments irrespective of head impulse direction.

