Computerized rotational head impulse test : age-dependent normative data

Abstract

The objective of this study was to determine the normative VOR gain output values of the crHIT with stationary visual targets (earthbound) in healthy participants in each decade age band of life; 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, and 70+ years. Seventy-seven community-dwelling participants (10 to 85 years) with normal lateral SCC functioning and no symptoms or history of vestibular dysfunction, were recruited through convenience sampling and assessed with the crHIT using stationary targets. These participants were assessed using two standard protocols in a randomized order. Pearson’s correlation coefficient and simple linear regression indicated no statistical significance between crHIT gain output and age (p>0.05) or sex (p>0.05). This demonstrated that the aVOR gain seems unaffected by aging and sex. Age-dependent normative data was calculated using the 2.5th 97.5th CI percentile method. The responses of aVOR gain values for crHIT are expected to occur within the range for lower limit RI of 0.85 - 0.9 and upper limit RI of 1.11 - 1.18 for 1030°/sec2 and for 1005°/sec2 , lower limit RI of 0.86-0.92 and upper limit RI of 1.13-1.16, respectively. It can be expected that 90% (CI) of the population with normal lateral SCC functioning will have aVOR gain values that fall within this range. Despite a statistically significant relationship that exists between aVOR gain output and age, the changes are minor, declining by 0.0088 units per 10 years, justifying the same normative data for all decade age bands.