Schellekens Mijntje M I, Li Hao, Boot Esther M, Verhoeven Jamie I, Ekker Merel S, Meijer Frederick J A, Kessels Roy P C, de Leeuw Frank-Erik, Tuladhar Anil M
Department of Neurology, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Netherlands (the).
Department of Radiology, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands (the).
Neuroimage Clin. 2025;45:103711. doi: 10.1016/j.nicl.2024.103711. Epub 2024 Nov 23.
Reduced white matter integrity outside the stroke lesion may be a potential contributor of post-stroke cognitive impairment. We aimed to investigate how a stroke lesion affects the integrity of surrounding white matter, and whether the integrity of the non-lesioned part of white matter tracts is associated with cognitive performance after ischemic stroke in young adults.
Patients from the ODYSSEY study, aged 18-49 years, with a first-ever ischemic stroke, underwent 3T MRI and cognitive assessment within six months after the index event. Using TractSeg and free water imaging, we analyzed free water corrected fractional anisotropy (FA), free water corrected mean diffusivity (MD), and free water (FW) of all white matter tracts outside the stroke lesion. We calculated FA and FW in the lesioned white matter tracts at 2 mm incremental distances from the lesion, extending up to 10 mm, represented as Z-scores using the diffusion measures of controls. We categorized patients as no/mild or major vascular cognitive disorder (VCD) and compared with a stroke-free control group (n = 23). Group differences in diffusion measures were examined. We investigated associations between FA, FW and cognitive performance across seven domains.
Among 66 patients (median age 40.3 years (IQR 31.3-46.2); 54.5 % women), 22 had major VCD. In the different lesion expansions, we found differences in FA (p = 0.009) and FW (p = 0.049). Patients with major VCD had lower FA [range of Cohen's d (0.65; 1.65)] and higher FW [Cohen's d (-1.40; -0.64)] values compared to controls, both in the hemisphere affected by the lesion and the unaffected hemisphere. Performance in processing speed correlated with FA across eight tracts in the affected hemisphere [range of R (0.30; 0.37)], and with FW in four tracts in the affected and three in the unaffected hemisphere [R (0.28; 0.38)].
In the first months after a stroke, we observed a trend of microstructural changes remote from the lesion that diminish as the distance from the lesion increases. Tissue changes in the white matter outside the lesion are present in both hemispheres, but are more pronounced in the hemisphere affected by the stroke, and may contribute to worse cognitive performance.
中风病灶外白质完整性降低可能是中风后认知障碍的一个潜在因素。我们旨在研究中风病灶如何影响周围白质的完整性，以及白质束未受损部分的完整性是否与年轻成年人缺血性中风后的认知表现相关。
来自奥德赛研究的年龄在18 - 49岁的首次缺血性中风患者在索引事件发生后的六个月内接受了3T磁共振成像（MRI）和认知评估。使用TractSeg和自由水成像技术，我们分析了中风病灶外所有白质束的自由水校正分数各向异性（FA）、自由水校正平均扩散率（MD）和自由水（FW）。我们在距病灶2毫米增量距离处计算受损白质束的FA和FW，最大延伸至10毫米，并使用对照组的扩散测量值表示为Z分数。我们将患者分为无/轻度或重度血管性认知障碍（VCD），并与无中风的对照组（n = 23）进行比较。检查扩散测量中的组间差异。我们研究了FA、FW与七个认知领域的认知表现之间的关联。
在66例患者中（中位年龄40.3岁（四分位间距31.3 - 46.2）；54.5%为女性），22例患有重度VCD。在不同的病灶扩展中，我们发现FA（p = 0.009）和FW（p = 0.049）存在差异。与对照组相比，重度VCD患者在受病灶影响的半球和未受影响的半球中，FA值较低[科恩d值范围（0.65；1.65）]，FW值较高[科恩d值范围（ - 1.40； - 0.64）]。处理速度方面的表现与受影响半球中八条束的FA相关[相关系数R范围（0.30；0.37）]，与受影响半球中的四条束以及未受影响半球中的三条束的FW相关[R（0.28；0.38）]。
在中风后的头几个月里，我们观察到远离病灶的微观结构变化趋势，这种变化随着与病灶距离的增加而减弱。病灶外白质的组织变化在两个半球都存在，但在受中风影响的半球中更明显，并且可能导致更差的认知表现。
