A review of the geometrical basis and the principles underlying the use and interpretation of the video head impulse test (vHIT) in clinical vestibular testing

Ian S Curthoys; Leigh A McGarvie; Hamish G MacDougall; Ann M Burgess; Gabor M Halmagyi; Jorge Rey-Martinez; Julia Dlugaiczyk

doi:10.3389/fneur.2023.1147253

A review of the geometrical basis and the principles underlying the use and interpretation of the video head impulse test (vHIT) in clinical vestibular testing

Front Neurol. 2023 Apr 11:14:1147253. doi: 10.3389/fneur.2023.1147253. eCollection 2023.

Authors

Ian S Curthoys¹, Leigh A McGarvie², Hamish G MacDougall³, Ann M Burgess¹, Gabor M Halmagyi², Jorge Rey-Martinez^{4

5}, Julia Dlugaiczyk⁶

Affiliations

¹ Vestibular Research Laboratory, School of Psychology, Faculty of Science, University of Sydney, Sydney, NSW, Australia.
² Neurology Department, Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
³ Institute of Academic Surgery, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
⁴ Neurotology Unit, Department of Otorhinolaryngology Head and Neck Surgery, Donostia University Hospital, Donostia-San Sebastian, Spain.
⁵ Biodonostia Health Research Institute, Otorhinolaryngology Area, Osakidetza Basque Health Service, Donostia-San Sebastian, Spain.
⁶ Department of Otorhinolaryngology, Head and Neck Surgery and Interdisciplinary Center of Vertigo, Balance and Ocular Motor Disorders, University Hospital Zurich (USZ), University of Zurich (UZH), Zurich, Switzerland.

Abstract

This paper is concerned mainly with the assumptions underpinning the actual testing procedure, measurement, and interpretation of the video head impulse test-vHIT. Other papers have reported in detail the artifacts which can interfere with obtaining accurate eye movement results, but here we focus not on artifacts, but on the basic questions about the assumptions and geometrical considerations by which vHIT works. These matters are crucial in understanding and appropriately interpreting the results obtained, especially as vHIT is now being applied to central disorders. The interpretation of the eye velocity responses relies on thorough knowledge of the factors which can affect the response-for example the orientation of the goggles on the head, the head pitch, and the contribution of vertical canals to the horizontal canal response. We highlight some of these issues and point to future developments and improvements. The paper assumes knowledge of how vHIT testing is conducted.

Keywords: HIMPs; HIT; SHIMPs; VOR; head impulse testing; vHIT; vestibular.

Publication types

Review

Grants and funding

Much of the work reported here has been supported by the Garnett Passe and Rodney Williams Memorial Foundation. We are very grateful for their continued support, and for that of the National Health and Medical Research Foundation of Australia. The Trustees of the Royal Prince Alfred Hospital Neurology Department have continuously supported our vestibular research. We also thank the ADANO (Working Group of German-speaking audiologists, neurotologists and otologists) for their ongoing support of JD.