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Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test
- Source :
- Frontiers in Neurology, Vol 6 (2015), Frontiers in Neurology
- Publication Year :
- 2015
- Publisher :
- Frontiers Media S.A., 2015.
-
Abstract
- Background/Hypothesis. With the video Head Impulse Test (vHIT), the vertical VOR gain is defined as (vertical eye velocity/vertical head velocity), but compensatory eye movements to vertical canal stimulation usually have a torsional component. To minimize the contribution of torsion to the eye movement measurement, the horizontal gaze direction should be directed 40º from straight ahead so it is in the plane of the stimulated canal plane pair. Hypothesis: as gaze is systematically moved horizontally away from canal plane alignment, the measured vertical VOR gain should decrease.Study Design. 10 healthy subjects, with vHIT measuring vertical eye movement to head impulses in the plane of the left anterior-right posterior (LARP) canal plane, with gaze at one of 5 horizontal gaze positions (40º (aligned with the LARP plane), 20º, 0º, -20º, -40º).Methods. Every head impulse was in the LARP plane. The compensatory eye movement was measured by the vHIT prototype system. The one operator delivered every impulse. Results. The canal stimulus remained identical across trials, but the measured vertical VOR gain decreased as horizontal gaze angle was shifted away from alignment with the LARP canal plane.Conclusion. In measuring vertical VOR gain with vHIT the horizontal gaze angle should be aligned with the canal plane under test.
- Subjects :
- genetic structures
semicircular canal
Acoustics
Impulse (physics)
vHIT
lcsh:RC346-429
03 medical and health sciences
0302 clinical medicine
medicine
030223 otorhinolaryngology
Simulation
lcsh:Neurology. Diseases of the nervous system
Original Research
Physics
Vestibular system
EYE MOVEMENT
vestibular
Semicircular canal
Eye movement
Head impulse test
Gaze
Eye position
medicine.anatomical_structure
Neurology
vestibulo-ocular reflex
Neurology (clinical)
sense organs
Vestibulo–ocular reflex
030217 neurology & neurosurgery
Neuroscience
Subjects
Details
- Language :
- English
- ISSN :
- 16642295
- Volume :
- 6
- Database :
- OpenAIRE
- Journal :
- Frontiers in Neurology
- Accession number :
- edsair.doi.dedup.....3376a6ff96f89bde6690b11d694edf48