Related Experiment Video
Updated: Jun 29, 2025
Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
Published on: April 18, 2019
Pre- and post-operative semicircular canal function evaluated by video head impulse test in patients with vestibular
Keishi Fujiwara1, Shinya Morita1, Hiroaki Motegi2
1Department of Otolaryngology-Head & Neck Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Objectives:
To evaluate pre- and post-operative semicircular canal function in patients with vestibular schwannoma (VS) by the video Head Impulse Test (vHIT).
Methods:
Nineteen patients with VS who underwent surgery were enrolled in this study. The gain in vestibulo-ocular reflex (VOR) and the degree of scatter in catch-up saccades were examined pre- and post-operatively for the semicircular canals in VS patients.
Results:
Ten of 19 cases (52.6 %) with VS were defined as demonstrating both superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) impairment from the results of pre-operative vHIT. Hearing level and subjective vestibular symptoms showed significant correlations with pre-operative semicircular canal function. Compared to pre-operative vHIT results, VOR gains within 1 month after surgery were significantly reduced in all three canals; however, significant differences had disappeared in the anterior and posterior semicircular canals at 6 months after surgery. Cases of unknown origin had a significantly greater reduction in posterior semicircular canal function after surgery compared with those with disease of IVN origin.
Conclusions:
As vHIT could evaluate pre-operative vestibular nerve impairment, post-operative VOR gain reduction and the degree of vestibular compensation, semicircular canal function evaluated by vHIT provides a good deal of useful information regarding VS patients undergoing surgery compared to caloric testing, and vHIT should be performed pre- and post-operatively for patients with VS.
