ANS036 - Comparison of vHIT with Caloric and Rotary Chair Measurements in Adult Patients with Balance Complaints
Sunday, May 1, 2022
10:48 AM – 10:55 AM CT
Location: Landmark A
Emma De Ravin, BS
Tiffany P. Hwa, MD
Alexandra E. Quimby, MD
Douglas C. Bigelow, MD
Jason A. Brant, MD
Michael J. Ruckenstein, MD
Steven J. Eliades, MD PhD
Perelman School of Medicine at the University of Pennsylvania Philadelphia, Pennsylvania
Objective: The role of recently introduced vestibular testing is unclear, and may yield differing results than traditional diagnostics. To reconcile these results, we sought to characterize the relationship between rotary chair (RC), caloric, and video head-impulse (vHIT) measurements in our multidisciplinary vestibular clinic.
Study Design: Retrospective chart review
Setting: Tertiary academic center
Patients: 277 symptomatic adult patients seen in a multidisciplinary vestibular clinic between 1/1/2019 and 12/31/2019.
Interventions/Outcome Measures: Correlations between vHIT, RC, and caloric testing measurements
Results: vHIT gains were more correlated with vestibulo-ocular reflex (VOR) gain on RC at low-to-mid frequencies (0.01-0.04Hz, r=0.12-0.26;p < 0.0001-0.0425) than at medium-to-high frequencies (0.26-0.32Hz, r=0.06-0.10;p=0.0899- 0.3166). vHIT gain was also better correlated with VOR phase at low-to-mid (r=-0.21;p=0.0004) than mid-to-high frequencies (r=-0.10-0.02;p=0.0964-0.7469). When compared to calorics, vHIT gains demonstrated weak correlations for warm (r=0.11-0.19) and cold (r=0.16-0.18). Similar to vHIT, cold calorics were better correlated with VOR gains at low frequencies (r=0.27-0.47;p= <0.0001) than high frequencies (r=0.06-0.19;p=0.0014-0.3335). Lastly, the presence of catchup saccades was best correlated with vHIT gain and slope (r=0.25-0.43) compared to all other vestibular testing modalities (low-frequency VOR, r=0.08-0.27; calorics, r=0.20-0.22).
Conclusions: While laboratory data suggests that vHIT reflects high-frequency vestibular physiology, these results show that vHIT values best correlate with low-to-mid frequency RC gain and phase in our symptomatic population. vHIT also displays a weak-to-moderate correlation with caloric measurements. These data may be useful to guide interpretation of mixed results from vestibular testing. Further study is needed to further contextualize vHIT data compared to RC and caloric results in specific vestibular conditions.
*Professional Practice Gap & Educational Need: vHIT is a relatively new addition to the neurotologist’s armamentarium that utilizes high-acceleration vestibular stimulation, and is marketed as equivalent to existing vestibular testing modalities like RC and caloric testing. The correlation of vHIT values with more traditional caloric and RC measurements is not yet understood.
*Learning Objective: To understand where vHIT interpretation fits into existing and widely accepted vestibular function testing modalities—can vHIT serve as a substitute test, particularly at institutions without the infrastructure for RC, or should it only be used as adjunctive data?
*Desired Result: To describe the role and integration of vHIT information in vestibular testing.
*Level of Evidence: Level IV
*Indicate IRB or IACUC: Approved by the University of Pennsylvania Institutional Review Board. Approval #831279.