Qiao Yufei, Zhu Min, Sun Wen, Sun Yang, Guo Hua, Shang Yingying
Department of Otorhinolaryngology, Peking Union Medical College Hospital, Beijing, China.
School of Educational Science, Shenyang Normal University, Shengyang, China.
Front Neurosci. 2022 Aug 25;16:935834. doi: 10.3389/fnins.2022.935834. eCollection 2022.
Single-sided deafness (SSD) is an extreme case of partial hearing deprivation and results in a significant decline in higher-order hearing abilities, including sound localization and speech-in-noise recognition. Clinical studies have reported that patients with SSD recover from these higher-order hearing abilities to some extent over time. Neuroimaging studies have observed extensive brain functional plasticity in patients with SSD. However, studies investigating the role of plasticity in functional compensation, particularly those investigating the relationship between intrinsic brain activity alterations and higher-order hearing abilities, are still limited. In this study, we used resting-state functional MRI to investigate intrinsic brain activity, measured by the amplitude of low-frequency fluctuation (ALFF), in 19 patients with left SSD, 17 patients with right SSD, and 21 normal hearing controls (NHs). All patients with SSD had durations of deafness longer than 2 years. Decreased ALFF values in the bilateral precuneus (PCUN), lingual gyrus, and left middle frontal gyrus were observed in patients with SSD compared with the values of NHs. Longer durations of deafness were correlated with better hearing abilities, as well as higher ALFF values in the left inferior parietal lobule, the angular gyrus, the middle occipital gyrus, the bilateral PCUN, and the posterior cingulate gyrus. Moreover, we observed a generally consistent trend of correlation between ALFF values and higher-order hearing abilities in specific brain areas in patients with SSD. That is, better abilities were correlated with lower ALFF values in the frontal regions and higher ALFF values in the PCUN and surrounding parietal-occipital areas. Furthermore, mediation analysis revealed that the ALFF values in the PCUN were a significant mediator of the relationship between the duration of deafness and higher-order hearing abilities. Our study reveals significant plasticity of intrinsic brain activity in patients with SSD and suggests that reorganization of intrinsic brain activity may be one of the compensatory mechanisms that facilitate improvement in higher-order hearing abilities in these patients over time.
单侧耳聋（SSD）是部分听力丧失的极端情况，会导致包括声音定位和噪声中语音识别在内的高阶听力能力显著下降。临床研究报告称，SSD患者的这些高阶听力能力会随着时间的推移在一定程度上恢复。神经影像学研究观察到SSD患者存在广泛的脑功能可塑性。然而，研究可塑性在功能补偿中的作用，特别是那些研究内在脑活动改变与高阶听力能力之间关系的研究仍然有限。在本研究中，我们使用静息态功能磁共振成像来研究19例左侧SSD患者、17例右侧SSD患者和21名听力正常对照者（NHs）的内在脑活动，通过低频波动幅度（ALFF）进行测量。所有SSD患者的耳聋持续时间均超过2年。与NHs相比，SSD患者双侧楔前叶（PCUN）、舌回和左侧额中回的ALFF值降低。耳聋持续时间越长，听力能力越好，同时左侧顶下小叶、角回、枕中回、双侧PCUN和后扣带回的ALFF值越高。此外，我们观察到SSD患者特定脑区的ALFF值与高阶听力能力之间存在总体一致的相关性趋势。也就是说，更好的能力与额叶区域较低的ALFF值以及PCUN和周围顶枕区域较高的ALFF值相关。此外，中介分析表明，PCUN的ALFF值是耳聋持续时间与高阶听力能力之间关系的重要中介。我们的研究揭示了SSD患者内在脑活动的显著可塑性，并表明内在脑活动的重组可能是促进这些患者高阶听力能力随时间改善的补偿机制之一。
