Laboratório de Investigação Médica (LIM-44), Instituto de Radiologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brasil.
Laboratório de Investigação Médica (LIM-44), Instituto de Radiologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brasil; Hospital Israelita Albert Einstein, São Paulo, Brasil.
Clin Neurol Neurosurg. 2022 Jun;217:107238. doi: 10.1016/j.clineuro.2022.107238. Epub 2022 Apr 2.
Brain ischemia affects the integrity of local white matter and regions that are distant to the primary lesion location. In this study, we analyzed the patterns of white matter microstructural damage and the cognitive performance of 22 patients with left hemisphere stroke. Patients were divided in two groups: one with target lesion affecting the left inferior frontal gyrus (left inferior frontal gyrus, LIFG, n = 11) and the other without ischemic lesion in this region (non-left inferior frontal gyrus, NLIFG, n = 11). Each group was compared with 11 matched healthy controls. Tract-Based Spatial Statistics was used to assess differences in diffusion tensor indices between the groups and for the association of white matter structure with cognitive performance. When compared to Controls, the LIFG showed extensive intra- and interhemispheric disconnection, with surrogate markers for tissue loss with demyelination in the corpus callosum, and microstructural changes that are independent of gross tissue loss in the contralateral hemisphere. The NLIFG group presented discrete alterations in white matter from the ipsilateral hemisphere, with surrogate markers for tissue loss with axonal injury. When LIFG is compared to NLIFG, white matter abnormalities with no gross tissue loss were observed in the corpus callosum and in the contralateral hemisphere. In addition LIFG had worse performance on cognitive functions. In conclusion, our results identify different diffusion profiles for LIFG and NLIFG groups, suggesting more extensive and pronounced white matter damage in the commissural and interhemispheric connections in the LIFG group, in addition to more pronounced cognitive impairment.
脑缺血影响局部白质的完整性和远离原发性病变部位的区域。在这项研究中，我们分析了 22 例左侧半球卒中患者的白质微观结构损伤模式和认知表现。患者分为两组：一组病变靶区累及左侧额下回（左侧额下回，LIFG，n=11），另一组病变靶区未累及该区域（非左侧额下回，NLIFG，n=11）。每组与 11 名匹配的健康对照进行比较。基于束的空间统计用于评估组间弥散张量指数的差异，以及白质结构与认知表现的相关性。与对照组相比，LIFG 表现出广泛的内-半球间连接中断，胼胝体中有脱髓鞘的组织丢失替代标志物，以及对侧半球无明显组织丢失的微观结构变化。NLIFG 组表现为同侧半球白质的离散改变，有组织丢失伴轴突损伤的替代标志物。当 LIFG 与 NLIFG 相比时，在胼胝体和对侧半球观察到无明显组织丢失的白质异常。此外，LIFG 在认知功能方面的表现更差。总之，我们的结果为 LIFG 和 NLIFG 组确定了不同的弥散谱，表明 LIFG 组的联合和半球间连接的白质损伤更广泛和明显，此外认知障碍更明显。
