Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States; Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, Champaign, IL 61820, United States.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States; Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States.
Brain Res. 2025 Jan 1;1846:149264. doi: 10.1016/j.brainres.2024.149264. Epub 2024 Oct 5.
Tinnitus is a phantom auditory sensation that commonly co-occurs with hearing loss. Both tinnitus and hearing loss can impact the quality of life, emotional well-being, and cognitive functioning of the affected individuals. While previous studies have highlighted structural alterations in hearing loss and/or tinnitus, the fundamental neural mechanisms underpinning tinnitus severity remain poorly understood. In this study, we conducted a voxel-based morphometry to investigate gray matter (GM) volume differences among groups of participants with varying tinnitus severity and hearing status, and controls within a large sample. We observed reduced GM volume in the left anterior insula and right planum polare in participants with hearing loss, regardless of their tinnitus status, compared to normal hearing controls. We noted decreased GM volume in the bilateral anterior and posterior insula for those with tinnitus and normal hearing compared to a normal hearing control group. Further, the tinnitus with hearing loss group showed decreased GM volume in the left planum polare, left inferior temporal gyrus, bilateral anterior temporal gyri, and right superior frontal gyrus compared to the normal hearing control group, suggesting a combined effect of hearing loss and tinnitus. While tinnitus severity did not show a significant overall effect, there was a significant positive correlation between tinnitus distress and GM volume in bilateral planum polare. Our findings enhance the understanding of structural brain changes related to hearing loss and tinnitus, and advance the overall knowledge of tinnitus pathophysiology, which can contribute to the development of more effective treatments for tinnitus.
耳鸣是一种常见于听力损失的幻听现象。耳鸣和听力损失都会影响患者的生活质量、情绪健康和认知功能。虽然先前的研究已经强调了听力损失和/或耳鸣中的结构改变，但支持耳鸣严重程度的基本神经机制仍知之甚少。在这项研究中，我们进行了基于体素的形态测量学分析，以研究在一个大样本中，不同耳鸣严重程度和听力状况的参与者与对照组之间的灰质（GM）体积差异。我们观察到，与正常听力对照组相比，无论耳鸣状况如何，听力损失患者的左侧前岛叶和右侧极平面的 GM 体积均减少。我们注意到，与正常听力对照组相比，耳鸣且听力正常的参与者双侧前岛叶和后岛叶的 GM 体积减少。此外，与正常听力对照组相比，伴听力损失的耳鸣组的左侧极平面、左侧颞下回、双侧前颞叶和右侧额上回的 GM 体积减少，表明听力损失和耳鸣的综合影响。虽然耳鸣严重程度总体上没有显著影响，但双侧极平面 GM 体积与耳鸣困扰之间存在显著正相关。我们的研究结果增强了对与听力损失和耳鸣相关的结构性脑改变的理解，推进了对耳鸣病理生理学的全面认识，这有助于开发更有效的耳鸣治疗方法。
