Shibata D K
Department of Radiology, University of Washington Medical Center, Seattle, Wash, USA.
AJNR Am J Neuroradiol. 2007 Feb;28(2):243-9.
The loss of a major sensory input early in life is known to cause alterations in neuronal connectivity and physiology at the cellular level, but effects on gross anatomy are less well understood. The purpose of this study was to compare volumetric structural brain MR imaging scans of deaf versus hearing subjects by using voxel-based morphometry (VBM). The hypothesis was that the deaf would have relative hypoplasia in the temporal lobe centers involved in hearing and speech.
T1-weighted volumetric images from 53 prelingually deaf persons and 51 control subjects were analyzed with VBM. Initial segmentations were spatially normalized, and then these deformation parameters were applied to the original images, which were again segmented. Statistic parametric mapping was then applied on a voxel-by-voxel basis to determine group differences and asymmetries.
The white matter analysis revealed a statistically significant focal deficit in the deaf persons in the left posterior superior temporal gyrus (STG), corresponding to white matter inferior to auditory cortex. Gray matter asymmetries in the deaf persons were overall similar to that in hearing persons but a focal loss of asymmetry was noted in the posterior STG white matter in the deaf persons.
These results support the hypothesis that there are gross alterations in brain anatomy as a consequence of early deafness. The white matter deficit in the posterior left superior temporal gyrus may represent hypoplasia of the auditory/speech related tracts. Hemispheric asymmetries however remain largely intact.
已知生命早期主要感觉输入的丧失会在细胞水平上引起神经元连接和生理功能的改变，但对大体解剖结构的影响了解较少。本研究的目的是通过基于体素的形态学测量（VBM）比较失聪与听力正常受试者的大脑结构容积磁共振成像扫描结果。假设是失聪者在参与听觉和言语的颞叶中心会有相对发育不全。
对53名语前聋患者和51名对照受试者的T1加权容积图像进行VBM分析。初始分割进行空间归一化，然后将这些变形参数应用于原始图像，再次进行分割。然后逐体素应用统计参数映射来确定组间差异和不对称性。
白质分析显示，失聪者左侧后颞上回（STG）存在统计学上显著的局灶性缺损，对应于听觉皮层下方的白质。失聪者的灰质不对称总体上与听力正常者相似，但在失聪者的后STG白质中发现了局灶性不对称缺失。
这些结果支持了早期失聪会导致大脑解剖结构发生大体改变这一假设。左侧后颞上回的白质缺损可能代表听觉/言语相关传导束发育不全。然而，半球不对称性在很大程度上仍然保持完整。
