Video HIT in adults with cochlear implants

Abstract

Objective: To evaluate the high-frequency function of bilateral lateral, posterior and anterior semicircular canals by video head impulse testing (vHIT) in adult patients with profound sensorineural hearing loss subjected to cochlear implant.Methods: A group of 19 adult bearers of monolateral cochlear implants for more than one year was assessed by vHIT on both sides with CI-ON modality and CI-OFF modality. The average of the VOR gains in each of the six semicircular canals was assessed. The Mann–Whitney U-test was used to compare VOR of implanted and non-implanted side semicircular canals (independent samples) and the Wilcoxon test was used to compare VOR with CI-ON modality and CI-OFF modality (related samples).Results: From a clinical point of view, no vestibular symptoms were observed although the median of VOR gain to vHIT was lower than normal values in most cases. Comparing the VOR in semicircular canals in the implanted side with that in the non-implanted side and each canal in the OFF modality compared to the ON modality, we observed no significant difference in VOR gain values, except in the lateral semicircular canal of the opposite side, in which the median of VOR gain was 0.80 (0.68–0.95) in OFF modality and 0.84 in ON modality (0.76–1.06) (p = .04).Conclusion: Even though cochlear implant has no negative impact on clinical vestibular function VOR gain in vHIT recordings is frequently reduced.