Test-Retest Reliability, Effects of Age and Comparison of Horizontal 2 Semicircular Canals Gain Values between Head Impulse and Suppression Head Impulse Paradigms.

BACKGROUND: This study investigates the test-retest reliability, aging effects, and differences in horizontal semicircular canals gain values between the head impulse paradigm and suppression head impulse paradigm. METHODS: Sixty healthy adult subjects aged 22-76-year-old (mean ± standard deviation=47.27 ± 18.29) participated in the head impulse paradigm and suppression head impulse paradigm using the video head impulse test. The Head impulse paradigm was used to assess all 6 semicircular canals, while suppression head impulse paradigm measured only the horizontal canals. Twenty subjects aged 22-40-year-old (25.25 ± 4.9) underwent a second session for the test-retest reliability. RESULTS: There were good test-retest reliability for both measures (right horizontal head impulse paradigm, intraclass correlation coefficient=0.80; left horizontal head impulse paradigm, intraclass correlation coefficient=0.77; right anterior head impulse paradigm, intraclass correlation coefficient=0.86; left anterior head impulse paradigm, intraclass correlation coefficient=0.78; right posterior head impulse paradigm, intraclass correlation coefficient=0.78; left posterior head impulse paradigm, intraclass correlation coefficient=0.75; right horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.76; left horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.79). The test-retest reliability for suppression head impulse paradigmanti-compensatory saccade latency and amplitude were moderate (right latency, intraclass correlation coefficient=0.61; left latency, intraclass correlation coefficient=0.69; right amplitude, intraclass correlation coefficient=0.69; left amplitude, intraclass correlation coefficient=0.58). There were no significant effects of age on head impulse paradigm and suppression head impulse paradigm vestibulo-ocular reflex gain values and suppression head impulse paradigmsaccade latency. However, the saccade amplitude became smaller with increasing age, P < .001. The horizontal suppression head impulse paradigm vestibuloocular reflex gain values were significantly lower than the head impulse paradigm for both sides (right, P = .004; left, P = .004). CONCLUSION: There was good test-retest reliability for both measures, and the gain values stabilized with age. However, suppression head impulse paradigm anti-compensatory saccade latency and amplitude had lower test-retest reliability than the gain. The suppression head impulse paradigm vestibulo-ocular reflex gain was lower than the head impulse paradigm and its anti-compensatory saccade amplitude reduced with increasing age.

Effects of Age on Cervical Vestibular Evoked Myogenic Potentials and Ocular Vestibular Evoked Myogenic Potentials Using 750 Hz Tone Burst Stimuli among Healthy Adults.

Background: The vestibular evoked myogenic potentials (VEMPs) response characteristics depend on age, stimulus and individual anatomical differences. Therefore, normative data are required for accurate VEMPs interpretations. This cross-sectional study investigates VEMPs age-related changes among healthy adults using 750 Hz short alternating tone burst (TB) stimuli. Methods: Fifty adults aged between 23 years old and 76 years old with a mean of 51.56 (SD = 16.44) years old underwent air-conducted (AC) cervical VEMP (cVEMP) and head taps ocular VEMPs (oVEMPs) testing. Results: The cVEMPs and oVEMPs response rates reduced significantly at the age of 50-year-old and above. No significant age trends were observed for both cVEMPs and oVEMPs latencies and asymmetry ratios. However, amplitude reduced with increasing age for both cVEMPs, P < 0.001 and oVEMPs, P = 0.01. No significant differences in cVEMPs and oVEMPs latencies, amplitude or asymmetry ratios were identified between gender. Conclusion: To the best of our knowledge, this is the first published normative data for cVEMPs and oVEMPS in Malaysia and Southeast Asia, obtained among healthy adults aged between 23 years old and 76 years old. Health professionals in the region can use these findings as VEMPs normative references in their clinical settings.