Department Institute of Speech and Hearing, Madras Medical College, Chennai, India.
Department of Audiology, School of Rehabilitation and Behavioral Sciences, Vinayaka Mission's Research Foundation, Aarupadai Veedu Medical College and Hospital Campus, Puducherry, India.
Am J Audiol. 2023 Dec 4;32(4):853-864. doi: 10.1044/2023_AJA-22-00184. Epub 2023 Sep 7.
Just noticeable difference for interaural time difference (JND-ITD) is a sensitive test to detect silent lesions and neural asynchrony along the auditory pathways among individuals with multiple sclerosis (MS), but it has not been studied with brainstem functional system scores (BFSS) and expanded disability status scale (EDSS). The study aims to assess the usefulness of JND-ITD thresholds in individuals with MS and relate to brainstem magnetic resonance imaging (MRI) lesions, BFSS, and disability (EDSS).
Standard group comparison design was adapted to compare the JND-ITD thresholds between individuals with MS ( = 45) and age and gender-matched healthy participants ( = 45). All participants underwent case history, neurological examination including BFSS and EDSS scoring, MRI brain imaging, minimental state examination, routine audiological evaluation, and ITD testing for high-pass filtered noise stimuli.
Of the 36 MS participants with abnormal JND-ITD thresholds, 22 (48.9%) participants could not identify maximum JND-ITD values (1,280 μs) in the ITD task. Abnormal JND-ITDs thresholds (139-1,280 μs) were obtained in 14 (31.11%) participants with MS. The JND-ITD thresholds were significantly different between the healthy and MS group. No significant association was found between the presence of ITD abnormality with the presence of brainstem lesions (MRI) and brainstem dysfunction (BFSS). Also, this study did not find any relationship between JND-ITD thresholds with disability (EDSS).
This study supports the findings that JND-ITD for high-pass filtered noise is a sensitive test to detect lesions along the auditory system. Even though JND-ITD thresholds did not relate with BFSS and EDSS scores, JND-ITD abnormalities can be of great value in identifying lesions along the auditory system, especially in the early stages of MS, when clinical neurological examination does not show any signs of brainstem dysfunction, disability, and MRI without any lesions in the brain.
听觉时间差（I TD）的可察觉差是一种灵敏的测试，可以检测多发性硬化症（MS）患者听觉通路中的隐性损伤和神经失同步，但尚未与脑干功能系统评分（BFSS）和扩展残疾状况量表（EDSS）一起进行研究。本研究旨在评估 I TD 阈值在 MS 患者中的有用性，并与脑干磁共振成像（MRI）损伤、BFSS 和残疾（EDSS）相关。
采用标准组比较设计，比较 MS 患者（n=45）与年龄和性别匹配的健康参与者（n=45）的 I TD 阈值。所有参与者接受病史、包括 BFSS 和 EDSS 评分的神经检查、脑部 MRI 成像、简易精神状态检查、常规听力评估和高通滤波噪声刺激的 I TD 测试。
在 36 名 MS 患者中有异常 I TD 阈值的参与者中，有 22 名（48.9%）参与者在 I TD 任务中无法识别最大 I TD 值（1,280 μs）。14 名（31.11%）MS 患者获得异常 I TD 阈值（139-1,280 μs）。健康组和 MS 组之间的 I TD 阈值有显著差异。未发现 I TD 异常与脑干病变（MRI）和脑干功能障碍（BFSS）之间存在相关性。此外，本研究未发现 I TD 阈值与残疾（EDSS）之间存在任何关系。
本研究支持 I TD 对于高通滤波噪声是一种灵敏的测试，可以检测听觉系统中的损伤的发现。即使 I TD 阈值与 BFSS 和 EDSS 评分无关，但 I TD 异常对于识别听觉系统中的损伤具有重要价值，尤其是在 MS 的早期阶段，此时临床神经系统检查没有显示出任何脑干功能障碍、残疾和脑部无病变的迹象。
