Test-retest and Interrater Reliability of the Video Head Impulse Test in the Pediatric Population

Objective: Determine reliability of horizontal and vertical video head impulse test (vHIT) and effect of maturation on angular vestibular ocular reflex (AVOR) gain estimations and peak head velocities of individual canals in typically developing children and adolescents. Design: Reliability study. Setting: University research laboratory Subjects: Two normal adults mean age 51.5 +/- 0.5 years and 28 typically developing children and adolescents mean age 10 +/- 3.5 years (range, 4.33-17.25 years). Main Outcome Measures: Mean AVOR gain estimate and peak head impulse velocity for individual canals. Results: In adult sample, mean AVOR gain estimates were 1.00 to 1.04 for lateral and 1.07 to 1.13 for vertical canals. In pediatric sample, mean AVOR gain estimates were 1.00 to 1.04 for lateral and 1.03 to 1.08 vertical canals. Mean AVOR gain intrarater reliability scores (intraclass correlation coefficient [ICC] >= 0.821 <= 0.945) and interrater reliability scores (ICC >= 0.800 <= 0.971) had good consistency. For each canal, across each age group, the range of percentage of trials with peak head velocities greater than 100 degrees/s was 32 to 49% right lateral, 31 to 49% left lateral, 0 to 11% right anterior, 3 to 4% left anterior, 1 to 7% right posterior, and 2 to 8% left posterior. Children aged less than 12 years, required 10 to 49% more trials compared with adults to obtain five valid, filtered trials. Adolescents required a similar number of trials compared with adults. Conclusion: In pediatric population, vHIT is a reliable clinical test to quantify individual canal function using high velocity head impulses. With children, it was difficult to acquire head impulse velocities of greater than 100 degrees/s especially in the plane of the vertical canals. These higher head velocities are required to reveal asymmetry in compensatory eye movements.