Effect of Facial Parameters on the Incidence of Rejection and Artifacts on the Video Head Impulse Test

Abstract

Background and Objectives: The video head impulse test (vHIT) is a useful tool that uses a high-speed infrared video camera and an inertial accelerometer to quantify the vestibulo-ocular reflex. Despite advancements in recording technology, physicians should be aware of measurement artifacts induced by examiners. However, little is known about the impact of facial anatomy on artifacts. Therefore, we investigated how variance in facial anatomy affects measurement artifacts. Materials and Methods: This study enrolled nine subjects from November 2018 through November 2019. A digital camera was used to measure facial parameters, including head ratio, binocular spacing, nasofrontal angle, depth of nasion, and pupil ratio. Two examiners performed vHITs with ICS Impulse System (GN Otometrics). All impulses were assessed for artifacts, including rejection, notch during head impulse (notchduring), notch after head impulse (notchafter), and rebound. Results: The rejection rate was significantly correlated with depth of nasion, as measured by the experienced examiner, and with pupil ratio, as measured by the inexperienced examiner. notchduring rate was significantly correlated with nasofrontal angle, as measured by the inexperienced examiner. Rebound rate was significantly correlated with head ratio, as measured by both examiners. Conclusions: Measurement artifacts were significantly correlated with head ratio, depth of nasion, nasofrontal angle, and pupil ratio. (J Clinical Otolaryngol 2021;32:101-110)