Mühlau M, Rauschecker J P, Oestreicher E, Gaser C, Röttinger M, Wohlschläger A M, Simon F, Etgen T, Conrad B, Sander D
Department of Neurology, Technische Universität München, D-81675 München, Germany.
Cereb Cortex. 2006 Sep;16(9):1283-8. doi: 10.1093/cercor/bhj070. Epub 2005 Nov 9.
Tinnitus is a common but poorly understood disorder characterized by ringing or buzzing in the ear. Central mechanisms must play a crucial role in generating this auditory phantom sensation as it persists in most cases after severing the auditory nerve. One hypothesis states that tinnitus is caused by a reorganization of tonotopic maps in the auditory cortex, which leads to an overrepresentation of tinnitus frequencies. Moreover, the participation of the limbic system in generating tinnitus has been postulated. Here we aimed at identifying brain areas that display structural change in tinnitus. We compared tinnitus sufferers with healthy controls by using high-resolution magnetic resonance imaging and voxel-based morphometry. Within the auditory pathways, we found gray-matter increases only at the thalamic level. Outside the auditory system, gray-matter decrease was found in the subcallosal region including the nucleus accumbens. Our results suggest that reciprocal involvement of both sensory and emotional areas are essential in the generation of tinnitus.
耳鸣是一种常见但了解甚少的病症，其特征为耳内出现铃声或嗡嗡声。中枢机制在产生这种听觉幻觉中必定起着关键作用，因为在切断听觉神经后，大多数情况下耳鸣仍会持续。一种假说认为，耳鸣是由听觉皮层中音调定位图的重新组织引起的，这会导致耳鸣频率的过度表征。此外，有人推测边缘系统参与了耳鸣的产生。在这里，我们旨在确定耳鸣中显示结构变化的脑区。我们通过使用高分辨率磁共振成像和基于体素的形态测量法，将耳鸣患者与健康对照进行了比较。在听觉通路内，我们发现仅丘脑水平的灰质增加。在听觉系统之外，在包括伏隔核在内的胼胝体下区域发现了灰质减少。我们的结果表明，感觉和情感区域的相互参与在耳鸣的产生中至关重要。
