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Updated: Jul 19, 2025
Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
Published on: April 18, 2019
[THE VIDEO HEAD IMPULSE TEST (VHIT): CAN WE RELY ON THE GAIN PARAMETER ALONE?]
Avi Shupak1, Khaldon Abo-Saleh2,3, Margalith Kaminer4
1Unit of Otoneurology, Lin Medical Center, Haifa, Faculty of Social Welfare and Health Sciences, University of Haifa.
Introduction:
While the bedside head impulse test evaluates the presence of refixation saccades (RS) as a measure of failing vestibulo-ocular reflex (VOR) the VOR gain calculated by the video head-impulse test (vHIT) is considered the primary measure for semicircular canal function while the role RS is still under evaluation.
Aims:
To evaluate the benefit of various RS characteristics towards the diagnosis of the left horizontal semicircular function by vHIT.
Methods:
The vHIT recordings of 40 patients with left sided horizontal VOR gains <0.8 were retrospectively evaluated for the presence of RS. The study groups included 20 patients with a final diagnosis of left horizontal semicircular canal dysfunction and 20 patients for whom vestibular dysfunction was ruled out.
Results:
Gain values > 0.72 were found in all patients with no vestibular disease, and in 4 (20%) patients having vestibulopathy. Significantly higher average left-sided RS velocity and frequency were found among the vestibular patients. VOR gain < 0.72 was found to be highly specific for the diagnosis of vestibular dysfunction. However, for gain values in the range of 0.72-0.79 the presence of RS with frequency > 80% improved vHIT sensitivity.
Conclusions:
Although VOR gain<0.8 is considered to reflect dysfunction, a significant false positive rate for left-sided horizontal vHIT was found for gains in the range of 0.72-0.79. The presence of RS with frequency >80% could improve vHIT diagnostic accuracy in these patients.
