Clinical characteristics of patients with unilateral auditory neuropathy

To analyze the clinical characteristics of patients with unilateral auditory neuropathy (UAN), and to provide guidance for future clinical diagnosis and research.

Patients who were clinically diagnosed with UAN from 2004 to 2019 were included. Clinical characteristics, audiological features, imaging findings, genetic test results and management effect were summarized and followed.

A total of 44 patients [mean age, 4.35 ± 4.39 years; 22 (50.00%) males and 22 (50.00%) females] were enrolled for analyses. Among the 38 patients who were tested by pure-tone or behavioral audiometry, the degree of hearing loss of the affected ear was characterized as mild in 2 ears (5.26%), moderate in 5 (13.16%), severe in 9 (23.68%) and profound in 22 (57.89%). For the 44 contralateral ears, 33 (75.00%) showed normal hearing and 11 (25.00%) presented with sensorineural hearing loss. Auditory brainstem responses were absent or abnormal in all 44 affected ears, while otoacoustic emissions and/or cochlear microphonics were present. Among the 18 patients who underwent magnetic resonance imaging (MRI), 7 (38.89%) presented cochlear nerve deficiency (CND). Nineteen candidate variants were found in 12 patients among the 15 UAN patients who were conducted targeted gene capture and next generation sequencing. Thirty patients were followed up by telephone to investigate their management effect.

Our study demonstrates comprehensive audiological features of patients with UAN to improve the clinical understanding and diagnosis. Some patients with UAN could show ipsilateral CND and MRI is essential to evaluate if the nerve is deficient. No pathogenic variants that directly related to the pathogenesis of UAN have been found in this study currently.