Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test
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 mov...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-03-01
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| Series: | Frontiers in Neurology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fneur.2015.00058/full |
| _version_ | 1811278920030355456 |
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| author | Leigh A. McGarvie Marta eMartínez López Ann M. Burgess Hamish G. MacDougall Ian S. Curthoys |
| author_facet | Leigh A. McGarvie Marta eMartínez López Ann M. Burgess Hamish G. MacDougall Ian S. Curthoys |
| author_sort | Leigh A. McGarvie |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-13T00:44:28Z |
| format | Article |
| id | doaj.art-66693016f4c543db940e4f3f64d171cd |
| institution | Directory Open Access Journal |
| issn | 1664-2295 |
| language | English |
| last_indexed | 2024-04-13T00:44:28Z |
| publishDate | 2015-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neurology |
| spelling | doaj.art-66693016f4c543db940e4f3f64d171cd2022-12-22T03:10:03ZengFrontiers Media S.A.Frontiers in Neurology1664-22952015-03-01610.3389/fneur.2015.00058137078Horizontal eye position affects measured vertical VOR gain on the video Head Impulse TestLeigh A. McGarvie0Marta eMartínez López1Ann M. Burgess2Hamish G. MacDougall3Ian S. Curthoys4Royal Prince Alfred HospitalClinica Universidad de NavarraUniversity of SydneyUniversity of SydneyUniversity of SydneyBackground/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.http://journal.frontiersin.org/Journal/10.3389/fneur.2015.00058/fullvestibularEYE MOVEMENTsemicircular canalvestibulo-ocular reflexvHIT |
| spellingShingle | Leigh A. McGarvie Marta eMartínez López Ann M. Burgess Hamish G. MacDougall Ian S. Curthoys Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test Frontiers in Neurology vestibular EYE MOVEMENT semicircular canal vestibulo-ocular reflex vHIT |
| title | Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test |
| title_full | Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test |
| title_fullStr | Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test |
| title_full_unstemmed | Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test |
| title_short | Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test |
| title_sort | horizontal eye position affects measured vertical vor gain on the video head impulse test |
| topic | vestibular EYE MOVEMENT semicircular canal vestibulo-ocular reflex vHIT |
| url | http://journal.frontiersin.org/Journal/10.3389/fneur.2015.00058/full |
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