Institute of Genetics, San Diego, California, USA.
Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, USA.
J Neurotrauma. 2022 Nov;39(21-22):1495-1506. doi: 10.1089/neu.2021.0239. Epub 2022 Aug 17.
Sport-related concussion (SRC) is an important public health issue. White-matter alterations after SRC are widely studied by neuroimaging approaches, such as diffusion magnetic resonance imaging (MRI). Although the exact anatomical location of the alterations may differ, significant white-matter alterations are commonly observed in long fiber tracts, but are never proven. In the present study, we performed streamline tractography to characterize the association between tract length and white-matter microstructural alterations after SRC. Sixty-eight collegiate athletes diagnosed with acute concussion (24-48 h post-injury) and 64 matched contact-sport controls were included in this study. The athletes underwent diffusion tensor imaging (DTI) in 3.0 T MRI scanners across three study sites. DTI metrics were used for tract-based spatial statistics to map white-matter regions-of-interest (ROIs) with significant group differences. Whole-brain white-mater streamline tractography was performed to extract "affected" white-matter streamlines (i.e., streamlines passing through the identified ROIs). In the concussed athletes, streamline counts and DTI metrics of the affected white-matter fiber tracts were summarized and compared with unaffected white-matter tracts across tract length in the same participant. The affected white-matter tracts had a high streamline count at length of 80-100 mm and high length-adjusted affected ratio for streamline length longer than 80 mm. DTI mean diffusivity was higher in the affected streamlines longer than 100 mm with significant associations with the Brief Symptom Inventory score. Our findings suggest that long fibers in the brains of collegiate athletes are more vulnerable to acute SRC with higher mean diffusivity and a higher affected ratio compared with the whole distribution.
运动相关性脑震荡（SRC）是一个重要的公共卫生问题。神经影像学方法（如扩散磁共振成像（MRI））广泛研究 SRC 后的白质改变。尽管改变的确切解剖位置可能不同，但在长纤维束中通常观察到明显的白质改变，但从未得到证实。在本研究中，我们进行了轨迹追踪，以描述 SRC 后轨迹长度与白质微观结构改变之间的关系。本研究纳入了 68 名被诊断为急性脑震荡的大学生运动员（受伤后 24-48 小时）和 64 名匹配的接触性运动对照者。运动员在三个研究地点的 3.0 T MRI 扫描仪中接受了扩散张量成像（DTI）。DTI 指标用于基于束的空间统计学，以绘制白质感兴趣区（ROI）的白质区域，以显示组间差异。进行全脑白质轨迹追踪以提取“受影响”的白质轨迹（即穿过鉴定的 ROI 的轨迹）。在脑震荡运动员中，受影响的白质纤维束的轨迹计数和 DTI 指标与同一参与者的未受影响的白质纤维束在相同的轨迹长度上进行了总结和比较。受影响的白质纤维束在 80-100mm 的长度上具有较高的轨迹计数，在长度大于 80mm 的长度上具有较高的长度调整后的受影响比。DTI 平均扩散率在长度大于 100mm 的受影响轨迹中较高，与Brief Symptom Inventory 评分有显著关联。我们的研究结果表明，与整个分布相比，大学生运动员大脑中的长纤维在急性 SRC 中更易受损，平均扩散率较高，受影响的比例较高。
