Impact of artifacts on VOR gain measures by video-oculography in the acute vestibular syndrome.

Mantokoudis, Georgios; Saber Tehrani, Ali S; Wozniak, Amy; Eibenberger, Karin; Kattah, Jorge C; Guede, Cynthia I; Zee, David S; Newman-Toker, David E (2016). Impact of artifacts on VOR gain measures by video-oculography in the acute vestibular syndrome. Journal of vestibular research - equilibrium & orientation, 26(4), pp. 375-385. IOS Press 10.3233/VES-160587

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OBJECTIVE

The video head impulse test (HIT) measures vestibular function (vestibulo-ocular reflex [VOR] gain - ratio of eye to head movement), and, in principle, could be used to make a distinction between central and peripheral causes of vertigo. However, VOG recordings contain artifacts, so using unfiltered device data might bias the final diagnosis, limiting application in frontline healthcare settings such as the emergency department (ED). We sought to assess whether unfiltered data (containing artifacts) from a video-oculography (VOG) device have an impact on VOR gain measures in acute vestibular syndrome (AVS).

METHODS

This cross-sectional study compared VOG HIT results 'unfiltered' (standard device output) versus 'filtered' (artifacts manually removed) and relative to a gold standard final diagnosis (neuroimaging plus clinical follow-up) in 23 ED patients with acute dizziness, nystagmus, gait disturbance and head motion intolerance.

RESULTS

Mean VOR gain assessment alone (unfiltered device data) discriminated posterior inferior cerebellar artery (PICA) strokes from vestibular neuritis with 91% accuracy in AVS. Optimal stroke discrimination cut points were bilateral VOR gain >0.7099 (unfiltered data) versus >0.7041 (filtered data). For PICA stroke sensitivity and specificity, there was no clinically-relevant difference between unfiltered and filtered data-sensitivity for PICA stroke was 100% for both data sets and specificity was almost identical (87.5% unfiltered versus 91.7% filtered). More impulses increased gain precision.

CONCLUSIONS

The bedside HIT remains the single best method for discriminating between vestibular neuritis and PICA stroke in patients presenting AVS. Quantitative VOG HIT testing in the ED is associated with frequent artifacts that reduce precision but not accuracy. At least 10-20 properly-performed HIT trials per tested ear are recommended for a precise VOR gain estimate.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Ear, Nose and Throat Disorders (ENT)
UniBE Contributor:	Mantokoudis, Georgios
Subjects:	600 Technology > 610 Medicine & health
ISSN:	0957-4271
Publisher:	IOS Press
Language:	English
Submitter:	Stefan Weder
Date Deposited:	17 May 2017 14:53
Last Modified:	05 Dec 2022 15:02
Publisher DOI:	10.3233/VES-160587
PubMed ID:	27814312
Uncontrolled Keywords:	Eye movement measurements; diagnosis; stroke; vertigo; vestibular neuritis; vestibulo-ocular reflex
URI:	https://boris.unibe.ch/id/eprint/95648