Zanin Julien, Rance Gary
Department of Audiology and Speech Pathology, The University of Melbourne, Parkville, Melbourne, Australia.
The HEARing Cooperative Research Centre, Melbourne, Victoria, Australia.
Ear Hear. 2025;46(2):371-381. doi: 10.1097/AUD.0000000000001589. Epub 2024 Sep 19.
Auditory neuropathy (AN), a complex hearing disorder, presents challenges in diagnosis and management due to limitations of current diagnostic assessment. This study aims to determine whether diffusion-weighted magnetic resonance imaging (MRI) can be used to identify the site and severity of lesions in individuals with AN.
This case-control study included 10 individuals with AN of different etiologies, 7 individuals with neurofibromatosis type 1 (NF1), 5 individuals with cochlear hearing loss, and 37 control participants. Participants were recruited through the University of Melbourne's Neuroaudiology Clinic and the Murdoch Children's Research Institute specialist outpatient clinics. Diffusion-weighted MRI data were collected for all participants and the auditory pathways were evaluated using the fixel-based analysis metric of apparent fiber density. Data on each participant's auditory function were also collected including hearing thresholds, otoacoustic emissions, auditory evoked potentials, and speech-in-noise perceptual ability.
Analysis of diffusion-weighted MRI showed abnormal white matter fiber density in distinct locations within the auditory system depending on etiology. Compared with controls, individuals with AN due to perinatal oxygen deprivation showed no white matter abnormalities ( p > 0.05), those with a neurodegenerative conditions known/predicted to cause VIII cranial nerve axonopathy showed significantly lower white matter fiber density in the vestibulocochlear nerve ( p < 0.001), while participants with NF1 showed lower white matter fiber density in the auditory brainstem tracts ( p = 0.003). In addition, auditory behavioral measures of speech perception in noise and gap detection were correlated with fiber density results of the VIII nerve.
Diffusion-weighted MRI reveals different patterns of anatomical abnormality within the auditory system depending on etiology. This technique has the potential to guide management recommendations for individuals with peripheral and central auditory pathway abnormality.
听觉神经病（AN）是一种复杂的听力障碍，由于当前诊断评估的局限性，在诊断和管理方面存在挑战。本研究旨在确定弥散加权磁共振成像（MRI）是否可用于识别AN患者的病变部位和严重程度。
本病例对照研究纳入了10例病因不同的AN患者、7例1型神经纤维瘤病（NF1）患者、5例耳蜗性听力损失患者和37名对照参与者。参与者通过墨尔本大学神经听力学诊所和默多克儿童研究所专科门诊招募。收集了所有参与者的弥散加权MRI数据，并使用基于固定点分析的表观纤维密度指标评估听觉通路。还收集了每位参与者的听觉功能数据，包括听力阈值、耳声发射、听觉诱发电位和噪声中的言语感知能力。
弥散加权MRI分析显示，根据病因不同，听觉系统内不同位置的白质纤维密度异常。与对照组相比，围产期缺氧所致AN患者未显示白质异常（p>0.05），已知/预测会导致第八颅神经轴突病的神经退行性疾病患者在前庭蜗神经中的白质纤维密度显著降低（p<0.001），而NF1患者在听觉脑干束中的白质纤维密度较低（p=0.003）。此外，噪声中的言语感知和间隙检测的听觉行为测量结果与第八神经的纤维密度结果相关。
弥散加权MRI根据病因揭示了听觉系统内不同的解剖学异常模式。该技术有可能为外周和中枢听觉通路异常的个体指导管理建议。
