Imaging of inner ear malformation in paediatric patients-a 10-year tertiary centre review.

Abstract

Sennaroglu's classification is the most accepted classification worldwide for inner ear and/or nerve malformation, although only limited data is available for the Asian population. This study aims to assess their relative frequency, summarise their radiological features, and determine their correlation with hearing impairment. Retrospective analysis of patients with imaging-proven inner ear and/or nerve malformation in a single tertiary hospital in Hong Kong in 2014-2023. Clinical data were reviewed along with relevant imaging findings. A total of 155 abnormal ears from 94 patients were included. All cases of Michel deformity (n = 4), rudimentary otocyst (n = 5), cochlear aplasia (n = 6) and common cavity (n = 3) show severe/profound hearing loss. Cochlear hypoplasia Type I (n = 2) and Type II (n = 6), and incomplete partition Type I (n = 5) also show severe/profound hearing loss; while cochlear hypoplasia Types III (n = 4) and Type IV (n = 8) and incomplete partition Type II (n = 28) show variable degrees of hearing deficit. Cochlear and vestibulocochlear nerve abnormalities were detected in 66% and 54% of cases, respectively. Generalised linear model analyses showed a correlation between the degree of hearing deficit with the presence of cochlear aperture atresia (OR = 2.562, p = 0.015), cochlear nerve atresia (OR = 2.599, p = 0.014), and vestibulocochlear nerve atresia (OR = 2.747, p = 0.064); and remained significant adjusting for the presence of cochlear abnormalities. A higher relative frequency of vestibulocochlear nerve and cochlear nerve abnormalities is observed in our study when compared with the existing literature. Cochlear nervous system abnormalities are most predictive of the degree of hearing impairment. Question Accurate assessment of the inner ear/cochlear nerve is important for guiding treatment, but literature on their relative frequency and correlation with hearing impairment is lacking. Findings Cochlear system abnormalities are more frequent than reported in the literature. Cochlear aperture atresia, cochlear, or vestibulocochlear nerve aplasia are significant predictors of hearing impairment. Clinical relevance This study highlights the importance of assessment of the cochlear nervous system with the use of high-resolution MRI in the evaluation of paediatric sensorineural hearing loss.