Ocular vestibular evoked myogenic potentials n10 response in autism spectrum disorders children with auditory hypersensitivity: an indicator of semicircular canal dehiscence.

UNLABELLED: Sensitivity to sound is one of the most commonly reported challenges in ASD. No compelling evidence shows that hearing of ASD individuals differs physiologically from normal peers. Superior semicircular canal dehiscence was found to be more common in ASD children with auditory hypersensitivity (29%) by means of high-resolution CT scan than the reported (14%) in normal pediatric population by other investigators. The increased prevalence of radiographic dehiscence might be due to inability of CT scan to visualize immature bone. We wished to determine whether ocular vestibular evoked myogenic potentials in ASD children with auditory hypersensitivity produces similar responses to those obtained in adult superior canal dehiscence, and whether it could help differentiate radiographic dehiscence due to bone immaturity from true canal dehiscence syndrome. A prospective study on 14 ASD children complaining of auditory hypersensitivity served as the study group. 15 ASD children without auditory hypersensitivity, age and gender matched, served as a control group. oVEMP and high-resolution CT scan of petrous and temporal bone were performed to all participants. Mean amplitude of n10 was 1.83 ± 0.11 and 1.79 ± 0.09 μV in the control group with mean peak latency of 9.79 ± 0.42 and 9.77 ± 0.30 ms for the right and left ears, respectively. Asymmetry ratio was 2.04 ± 1.37. In the study group, the mean amplitude of n10 was 2.07 ± 0.46 and 1.89 ± 0.30 μV, with mean peak latency of 9.52 ± 0.33 and 9.59 ± 0.21 ms for the right and left ears, respectively, with asymmetry 5.23 ± 6.93%. No statistically significant difference was observed for the studied parameters. In the study group, the number of ears showing an augmented amplitude (>2SD) of n10 was (N = 5). Furthermore, the study group demonstrated a radiographic SSCD in 6 ears. n10 was normal in the control group while radiographic SSCD was observed in 3 of them.

CONCLUSION: oVEMPs show diagnostic ability in differentiating ASD children complaining of auditory hypersensitivity due to superior canal dehiscence from those with radiographic dehiscence only due to bone immaturity or atypical cortical development.