Profant Oliver, Škoch Antonín, Tintěra Jaroslav, Svobodová Veronika, Kuchárová Diana, Svobodová Burianová Jana, Syka Josef
Department of Auditory Neuroscience, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia.
Department of Otorhinolaryngology, 3rd Faculty of Medicine, Faculty Hospital Kralovske Vinohrady, Charles University, Prague, Czechia.
Front Aging Neurosci. 2020 Dec 4;12:553461. doi: 10.3389/fnagi.2020.553461. eCollection 2020.
Age related hearing loss (presbycusis) is a natural process represented by elevated auditory thresholds and decreased speech intelligibility, especially in noisy conditions. Tinnitus is a phantom sound that also potentially leads to cortical changes, with its highest occurrence coinciding with the clinical onset of presbycusis. The aim of our project was to identify age, hearing loss and tinnitus related structural changes, within the auditory system and associated structures. Groups of subjects with presbycusis and tinnitus (22 subjects), with only presbycusis (24 subjects), young tinnitus patients with normal hearing (10 subjects) and young controls (17 subjects), underwent an audiological examination to characterize hearing loss and tinnitus. In addition, MRI (3T MR system, analysis in Freesurfer software) scans were used to identify changes in the cortical and subcortical structures. The following areas of the brain were analyzed: Heschl gyrus (HG), planum temporale (PT), primary visual cortex (V1), gyrus parahippocampus (PH), anterior insula (Ins), amygdala (Amg), and hippocampus (HP). A statistical analysis was performed in R framework using linear mixed-effects models with explanatory variables: age, tinnitus, laterality and hearing. In all of the cortical structures, the gray matter thickness decreased significantly with aging without having an effect on laterality (differences between the left and right hemispheres). The decrease in the gray matter thickness was faster in the HG, PT and Ins in comparison with the PH and V1. Aging did not influence the surface of the cortical areas, however there were differences between the surface size of the reported regions in the left and right hemispheres. Hearing loss caused only a borderline decrease of the cortical surface in the HG. Tinnitus was accompanied by a borderline decrease of the Ins surface and led to an increase in the volume of Amy and HP. In summary, aging is accompanied by a decrease in the cortical gray matter thickness; hearing loss only has a limited effect on the structure of the investigated cortical areas and tinnitus causes structural changes which are predominantly within the limbic system and insula, with the structure of the auditory system only being minimally affected.
年龄相关性听力损失（老年性聋）是一个自然过程，表现为听觉阈值升高和言语可懂度下降，尤其是在嘈杂环境中。耳鸣是一种幻听，也可能导致皮质变化，其最高发生率与老年性聋的临床发病时间一致。我们项目的目的是确定听觉系统及相关结构内与年龄、听力损失和耳鸣相关的结构变化。将患有老年性聋和耳鸣的受试者组（22名受试者）、仅患有老年性聋的受试者组（24名受试者）、听力正常的年轻耳鸣患者组（10名受试者）和年轻对照组（17名受试者）进行听力学检查，以表征听力损失和耳鸣情况。此外，使用MRI（3T MR系统，在Freesurfer软件中进行分析）扫描来识别皮质和皮质下结构的变化。对大脑的以下区域进行了分析：颞横回（HG）、颞平面（PT）、初级视觉皮层（V1）、海马旁回（PH）、前岛叶（Ins）、杏仁核（Amg）和海马体（HP）。在R框架中使用线性混合效应模型进行统计分析，解释变量包括：年龄、耳鸣、侧别和听力。在所有皮质结构中，灰质厚度随年龄增长显著下降，且对侧别无影响（左右半球之间的差异）。与PH和V1相比，HG、PT和Ins的灰质厚度下降更快。衰老并未影响皮质区域的表面积，然而左右半球报告区域的表面积大小存在差异。听力损失仅导致HG皮质表面积出现临界性下降。耳鸣伴随着Ins表面积的临界性下降，并导致Amy和HP体积增加。总之，衰老伴随着皮质灰质厚度的下降；听力损失对所研究的皮质区域结构仅有有限影响，耳鸣会导致主要在边缘系统和岛叶内的结构变化，而听觉系统结构仅受到最小程度的影响。
