Effect of aging and direction of impulse in video head impulse test.

OBJECTIVE

The aim of this study was to identify the difference of gain value in the video head impulse test (vHIT) according to the age of the patient and the direction of the impulse.

METHOD

All participants were subjected to vHIT with horizontal semicircular canal (HSCC). vHIT with vertical canal (posterior and anterior semicircular canal [PSCC and ASCC]) additionally was performed in 434 participants.

RESULTS

The mean vestibulo-ocular reflex (VOR) gain was maintained in patients in the HSCC at below 70 years (1.025 ± 0.08) and in the vertical canal at below 80 years (PSCC: 0.965 ± 0.12, ASCC: 0.975 ± 0.14). However, the decrease of VOR gain was significant in patients over 70 years in the HSCC (0.978 ± 0.35, P < .001) and in patients over 80 years in the vertical canal (PSCC: 0.828 ± 0.16, ASCC: 0.851 ± 0.13, P < .001). In addition, a VOR gain of rightward impulse was higher than the leftward impulse, but there was no difference based on the direction of impulse in the vertical impulse test.

CONCLUSION

VOR gain declines with increasing age, over 70 years on the horizontal canal, and over 80 years on the vertical canal. Additionally, horizontal VOR gain of rightward impulse was higher than the leftward impulse in right-eye recordings only, but the vertical canal showed no difference of gain according to the direction of impulse.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:E228-E233, 2018.