Gough Patricia M, Connally Emily L, Howell Peter, Ward David, Chesters Jennifer, Watkins Kate E
Department of Psychology, Maynooth University, Maynooth, Co. Kildare, Ireland.
Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, OX1 3UD, UK.
J Fluency Disord. 2018 Mar;55:94-105. doi: 10.1016/j.jfludis.2017.06.003. Epub 2017 Jun 16.
Previous studies have reported that the planum temporale - a language-related structure that normally shows a leftward asymmetry - had reduced asymmetry in people who stutter (PWS) and reversed asymmetry in those with severe stuttering. These findings are consistent with the theory that altered language lateralization may be a cause or consequence of stuttering. Here, we re-examined these findings in a larger sample of PWS.
We evaluated planum temporale asymmetry in structural MRI scans obtained from 67 PWS and 63 age-matched controls using: 1) manual measurements of the surface area; 2) voxel-based morphometry to automatically calculate grey matter density. We examined the influences of gender, age, and stuttering severity on planum temporale asymmetry.
The size of the planum temporale and its asymmetry were not different in PWS compared with Controls using either the manual or the automated method. Both groups showed a significant leftwards asymmetry on average (about one-third of PWS and Controls showed rightward asymmetry). Importantly, and contrary to previous reports, the degree of asymmetry was not related to stuttering severity. In the manual measurements, women who stutter had a tendency towards rightwards asymmetry but men who stutter showed the same degree of leftwards asymmetry as male Controls. In the automated measurements, Controls showed a significant increase in leftwards asymmetry with age but this relationship was not observed in PWS.
We conclude that reduced planum temporale asymmetry is not a prominent feature of the brain in PWS and that the asymmetry is unrelated to stuttering severity.
先前的研究报告称，颞平面——一种通常表现为左向不对称的与语言相关的结构——在口吃者（PWS）中不对称性降低，而在严重口吃者中则出现不对称反转。这些发现与语言侧化改变可能是口吃的原因或结果这一理论相一致。在此，我们在更大样本的PWS中重新审视了这些发现。
我们使用以下方法评估了从67名PWS和63名年龄匹配的对照者获得的结构MRI扫描中的颞平面不对称性：1）手动测量表面积；2）基于体素的形态计量学以自动计算灰质密度。我们研究了性别、年龄和口吃严重程度对颞平面不对称性的影响。
使用手动或自动方法时，PWS的颞平面大小及其不对称性与对照组相比并无差异。两组平均均表现出显著的左向不对称（约三分之一的PWS和对照组表现出右向不对称）。重要的是，与先前的报告相反，不对称程度与口吃严重程度无关。在手动测量中，口吃女性有右向不对称的倾向，但口吃男性与男性对照组表现出相同程度的左向不对称。在自动测量中，对照组随年龄增长左向不对称显著增加，但在PWS中未观察到这种关系。
我们得出结论，颞平面不对称性降低不是PWS大脑的突出特征，且这种不对称性与口吃严重程度无关。
