The Spectrum and Frequency of Inner Ear Anomalies in Patients with Congenital Hearing Impairment in Yakutia

Abstract

Objective. To analyze the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia.Material and methods. A total of 165 patients with congenital hearing impairment were surveyed. All the patients were examined by an audiologist, an educational audiologist, and a neuropsychiatrist. All the patients underwent X-ray computed tomography (X-ray CT) of temporal bone structures (which was supplemented by magnetic resonance imaging (MRI) in some cases).Results. Based on modern ideas about inner ear anomalies and their classification, the authors first analyzed the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia. Inner ear malformations were identified in 16 (9.7%) of the 165 patients with hearing impairment, which corresponds to that in the previously studied samples of deaf people in different countries (from 3% to 35%). Of the inner ear structures, the cochlea and vestibule were more commonly affected. Abnormalities of the internal auditory meatus, semicircular canals, and vestibular aqueduct were less common. In general, the spectrum of anomalies was represented by 7 different malformations. Incomplete partition type II (IP-II) (34.3%) came first in incidence among all the abnormalities. Incomplete partition type III (IP-III) (18.7%) ranked second in incidence. The expansion of the internal auditory meatus (12.5%) and vestibular aqueduct (12.5%) occupied the third place. Inner ear anomalies occurred as concurrences that are difficult to interpret and classify in half (50%) of all the cases.Conclusion. Analysis of the spectrum and frequency of temporal bone abnormalities in Yakutia suggests that every 10 patients with congenital hearing impairment have one or another inner ear structural malformation (9.7%) and require accurate and timely diagnosis using up-to-date X-ray CT and MRI techniques.