Children with unilateral cochlear nerve canal stenosis have bilateral cochleovestibular anomalies

Abstract

Objectives/Hypothesis To investigate the cochleovestibular apparatus bilaterally in children with isolated unilateral bony cochlear nerve canal (bCNC) stenosis. Study Design Retrospective review. Methods Imaging studies of children with unilateral bCNC stenosis (<1.0 mm) on computed tomography imaging (N = 36) were compared with controls imaged due to trauma without temporal bone injury (N = 32). Twenty‐six measurements were obtained in each ear, assessing the bony internal auditory canal (IAC), cochlea, and vestibular end‐organs, and were analyzed using one‐way analysis of variance for intersubject comparisons and paired t tests for intrasubject comparisons with a Bonferroni adjustment for multiple comparisons (P = .0006). Results Patients with bCNC stenosis had a smaller IAC (P < .000) and cochlea (P < .000) on the stenotic side as compared with controls. Although the vestibular end‐organ was also smaller in bCNC ears, this difference was not significant. The contralateral ear also had a smaller bCNC (P < .000) and cochlea (P < .000) as compared with controls, although to a lesser degree than the stenotic side. Conclusions Children with unilateral bCNC stenosis have abnormal biometry of both the cochlea and the vestibular end‐organ in the affected and the normal contralateral ear as compared with controls. Level of Evidence 3b Laryngoscope, 129:2403–2408, 2019

Imaging findings in pediatric single‐sided deafness and asymmetric hearing loss

“…A previous study described a wider cochlear basal turn lumen and abnormal lateral SCC bony island in the contralateral normal hearing ears of children with unilateral hearing loss, compared with controls . Similarly, a higher rate of contralateral cochleovestibular anomalies was reported in children with unilateral hearing loss and cochlear nerve canal stenosis, compared with controls . The authors proposed a role for abnormal signaling during embryogenesis that affects the temporal bones bilaterally, yet the clinical significance of these findings is to be elucidated.…”

“…15 Similarly, a higher rate of contralateral cochleovestibular anomalies was reported in children with unilateral hearing loss and cochlear nerve canal stenosis, compared with controls. 16 The authors proposed a role for abnormal signaling during embryogenesis that affects the temporal bones bilaterally, yet the clinical significance of these findings is to be elucidated. A previous study by the senior author showed that 10.6% of 142 children with unilateral hearing loss later developed contralateral hearing loss, similar to the 15% rate of bilateral findings we observed in the current study.…”

Correlation of cochlear aperture stenosis with cochlear nerve deficiency in congenital unilateral hearing loss and prognostic relevance for cochlear implantation

“…Even this study did not include MR images nor a normal control group. Vilchez-Madrigal et al 42 compared the CT imaging studies of 36 children with unilateral CA stenosis (< 1.0 mm), with controls without temporal bone injury. Contralateral ears had smaller CA ( p < 0.00) and cochlea ( p < 0.00) than controls, although to a lesser extent than on the stenotic side.…”

Internal ear morphometry in pediatrics: a comparison between neurosensorial hearing loss population and control group

“…A narrow IAC is found more often in children with SNHL compared with children without SNHL 9,18,20 . IAC stenosis should be an absolute contraindication to cochlear implantation.…”