Interhemispheric Auditory Cortical Synchronization in Asymmetric Hearing Loss.
Interhemispheric Auditory Cortical Synchronization in Asymmetric Hearing Loss.
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DOI：
10.1097/aud.0000000000001027
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发表时间：
2021
期刊：
影响因子：
3.7
通讯作者：
Cheung SW
中科院分区：
文献类型：
--
作者：
Chang JL;Crawford ED;Bhutada AS;Henderson Sabes J;Chen J;Cai C;Dale CL;Findlay AM;Mizuiri D;Nagarajan SS;Cheung SW
在正常听力（NH）中，两个半球的听觉皮层对单侧呈现的音调刺激的激活是不同步的，但在成人发病的不对称听力损失（AHL）伴有单侧耳聋的极端情况下，听觉皮层的激活是同步的。我们解决了这两种半球间时间组织锚定状态之间的广泛知识差距。本研究的目的如下：(1)在横断面研究中，利用耳间阈值差的大小作为自变量，绘制出从异步到同步的半球间时间重组的轨迹；(2)在重复测量的纵向研究中，通过放大可辅助的较差耳，评估半球间同步与听力在噪音表现中的可逆性。横断面和纵向队列包括49名受试者（AHL, N = 21；男性11人，女性10人，平均年龄48岁）和NH （N = 28；男性16人，女性12人，平均年龄45岁）。两组的最大耳间阈值差为0 ~ 65 dB。脑磁图分析的重点是，在分别对应于较好耳朵和较差耳朵的最大和最小耳间阈值差异的频率（0.5、1、2、3或4 kHz）的单耳音调刺激下，在50毫秒至150毫秒之间，来自两个半球听觉皮层的M100峰值反应的潜伏期。纵向AHL队列取自横断面AHL队列中的三名受试者（均为男性，年龄49 - 60岁，各种AHL病因，至少2年无扩增）。所有纵向研究对象均接受较差耳单耳放大治疗，并在基线和放大后第3、6和12个月对噪声听力中的M100反应潜伏期和快速言语进行重复测量检查。在所有刺激条件下，同侧半球的M100反应峰值潜伏期均滞后于对侧半球。三大类最大耳间阈值差值的平均（SD）半球间潜伏期差值（同侧小于对侧）如下：NH(≤10 dB) -8.6 (3.0) msec；AHL (15 ~ 40 dB) -3.0 (1.2) msec；AHL(≥45 dB) -1.4 (1.3) msec。然后，利用差值的大小分别定义了异步、混合异步和同步、同步的大脑间时间组织状态。在12个月的时间里，纵向受试者中较差的耳朵的放大推动了半球间组织从基线同步到放大后异步的变化，并改善了基线损伤者的噪音听力表现。AHL的半球间颞叶组织被锚定在NH的异步状态和单侧耳聋的同步状态之间。对于15 ~ 40 dB的非对称震级，异步和同步的中间混合状态是连续的和可逆的。对AHL中较差的一只耳进行放大可以改善噪声性能，并恢复两半球听觉皮层的正常时间组织。在12个月的时间里，较差的耳朵单耳放大后，半球间同步从基线同步恢复到正常的听力改善。
Auditory cortical activation of the two hemispheres to monaurally presented tonal stimuli has been shown to be asynchronous in normal hearing (NH) but synchronous in the extreme case of adult-onset asymmetric hearing loss (AHL) with single-sided deafness. We addressed the wide knowledge gap between these two anchoring states of interhemispheric temporal organization. The objectives of this study were as follows: (1) to map the trajectory of interhemispheric temporal reorganization from asynchrony to synchrony using magnitude of interaural threshold difference as the independent variable in a cross-sectional study and (2) to evaluate reversibility of interhemispheric synchrony in association with hearing in noise performance by amplifying the aidable poorer ear in a repeated measures, longitudinal study. The cross-sectional and longitudinal cohorts were comprised of 49 subjects (AHL; N = 21; 11 male, 10 female; mean age = 48 years) and NH (N = 28; 16 male, 12 female; mean age = 45 years). The maximum interaural threshold difference of the two cohorts spanned from 0 to 65 dB. Magnetoencephalography analyses focused on latency of the M100 peak response from auditory cortex in both hemispheres between 50 msec and 150 msec following monaural tonal stimulation at the frequency (0.5, 1, 2, 3, or 4 kHz) corresponding to the maximum and minimum interaural threshold difference for better and poorer ears separately. The longitudinal AHL cohort was drawn from three subjects in the cross-sectional AHL cohort (all male; ages 49 to 60 years; varied AHL etiologies; no amplification for at least 2 years). All longitudinal study subjects were treated by monaural amplification of the poorer ear and underwent repeated measures examination of the M100 response latency and quick speech in noise hearing in noise performance at baseline, and postamplification months 3, 6, and 12. The M100 response peak latency values in the ipsilateral hemisphere lagged those in the contralateral hemisphere for all stimulation conditions. The mean (SD) interhemispheric latency difference values (ipsilateral less contralateral) to better ear stimulation for three categories of maximum interaural threshold difference were as follows: NH (≤ 10 dB)—8.6 (3.0) msec; AHL (15 to 40 dB)—3.0 (1.2) msec; AHL (≥ 45 dB)—1.4 (1.3) msec. In turn, the magnitude of difference values were used to define interhemispheric temporal organization states of asynchrony, mixed asynchrony and synchrony, and synchrony, respectively. Amplification of the poorer ear in longitudinal subjects drove interhemispheric organization change from baseline synchrony to postamplification asynchrony and hearing in noise performance improvement in those with baseline impairment over a 12-month period. Interhemispheric temporal organization in AHL was anchored between states of asynchrony in NH and synchrony in single-sided deafness. For asymmetry magnitudes between 15 and 40 dB, the intermediate mixed state of asynchrony and synchrony was continuous and reversible. Amplification of the poorer ear in AHL improved hearing in noise performance and restored normal temporal organization of auditory cortices in the two hemispheres. The return to normal interhemispheric asynchrony from baseline synchrony and improvement in hearing following monoaural amplification of the poorer ear evolved progressively over a 12-month period.