Background and purpose

Subcortical ischemic stroke usually leads to the geometric microstructural changes in the orientation of peri-infarct white matter fiber. We conducted the study to determine the microstructural changes in the white matter fiber orientation in post stroke patients with and without cognitive impairment (PSCI, NPSCI), and to investigate the impact of peri-infarct white matter damage on the morphology and functional connectivity of their projective cerebral regions.

Methods

A novel mathematical framework called Director Field Analysis (DFA) was applied to study the microstructural changes in the orientation of white matter fiber in PSCI (n = 23), NPSCI (n = 17), and cognitively normal (CN, n = 29) individuals.

Results

PSCI patients had extensive abnormalities in the orientation of white matter fiber in the corpus callosum, bilateral internal capsule, external capsule, forceps major, forceps minor, and corticospinal tract in comparison with NPSCI and CN. NPSCI patients also showed significant increases in bend and twist of white matter fiber orientation in the internal capsule in comparison with CN. Seed-based functional connectivity analysis showed that peri-infarct white matter deficits indicate a significant impact on functional connectivity with related cortical regions, suggesting the coexistence of impairment and compensation in post-stroke. In addition, these peri-infarct white matter damages and abnormal functional connectivity were significantly correlated with cognitive scores. Machine learning model also indicated that these changes in white matter fiber orientation and functional connectivity can predict the cognitive status in post-stroke.

Conclusions

Post-stroke patients experienced pathological damage in the orientation of peri-infarct white matter fiber. The peri-infarct white matter damage may further induce the abnormal functional connectivity in projective cerebral regions. These degenerations of peri-infarct white matter fiber and associated functional connectivity changes may mediate the cognitive impairment in post-stroke.

中文翻译：

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脑卒中后脑白质几何微结构损伤功能代偿

背景和目的

皮质下缺血性卒中通常导致梗死周围白质纤维取向的几何微观结构变化。我们进行了这项研究，以确定有和没有认知障碍（PSCI，NPSCI）的脑卒中后患者白质纤维取向的微观结构变化，并研究梗塞周围白质损伤对其形态和功能连接的影响。投射性大脑区域。

方法

应用称为导向场分析 (DFA) 的新型数学框架来研究 PSCI (n = 23)、NPSCI (n = 17) 和认知正常 (CN, n = 29) 中白质纤维取向的微观结构变化个人。

结果

与 NPSCI 和 CN 相比，PSCI 患者胼胝体、双侧内囊、外囊、大镊子、小镊子和皮质脊髓束的白质纤维方向存在广泛异常。与 CN 相比，NPSCI 患者的内囊白质纤维取向的弯曲和扭曲也显着增加。基于种子的功能连接分析表明，梗塞周围白质缺陷表明对与相关皮质区域的功能连接有显着影响，表明卒中后损伤和代偿共存。此外，这些梗塞周围白质损伤和功能连接异常与认知评分显着相关。

结论

中风后患者在梗塞周围白质纤维的方向上经历了病理性损伤。梗塞周围白质损伤可能进一步诱发投射脑区的异常功能连接。这些梗塞周围白质纤维的退化和相关的功能连接变化可能介导中风后的认知障碍。