Evaluation of vestibulo-ocular reflex with functional head impulse test in healthy individuals: normative values

Objectives: This study aimed to determine the normative values of the functional head impulse test (fHIT) test in healthy young adults.Materials and methods: The study included 100 individuals, 58 females and 42 males, aged 20-25 years. Beon Solution Zero Branco (TV) fHIT test was applied to all participants. FHIT results were analyzed in terms of lateral-posterior-anterior semicircular canals (SSCs), gender, and right-left ear.Results: In the fHIT test, for the lateral SSC the mean percent correct answer (%CA) values for 4,000-6,000 degrees/s(2) and 1,000-7,000 degrees/s(2) were 88.52 +/- 9.04 and 89.91 +/- 6.95, respectively; for the posterior SSC, the mean %CA values for SSC 3000-6,000 degrees/s(2) and 1,000-7,000 degrees/s(2) were 90.63 +/- 8.69 and 91.16 +/- 7.42, respectively; for the anterior SSC, the mean %CA values for 3,000-6,000 degrees/s(2) and 1,000-7,000 degrees/s(2) were 91.21 +/- 7.96 and 91.49 +/- 7.13, respectively. There was no statistically significant difference between the right and left ear in %CA values at all accelerations in all SSCs (p > 0.05). There was a statistically significant difference between genders in the mean %CA values for 6,000-7,000 degrees/s(2), 4,000-6,000 degrees/s(2), and 1,000-7,000 degrees/s(2) in the lateral SSC and 3,000-6,000 degrees/s(2) in the anterior SSC (p < 0.05).Conclusion: The FHIT is a noninvasive test battery that functionally evaluates the VOR of the six semicircular canals. In clinical use, the determination of normative values at all accelerations (1,000-7,000 degrees/s(2)) constitutes an important database for future studies to distinguish pathologic results.