■先前的MRI研究表明,患有皮质下缺血性血管疾病(SIVD)的患者表现出白质损伤,灰质萎缩和记忆障碍,但是这些异常变化的具体特征和相互关系尚未完全阐明。
■我们收集了29名患有认知障碍(SIVD-CI)的SIVD患者的MRI数据和记忆评分,29名认知未受损的SIVD患者(SIVD-CU)和32名正常对照(NC)。随后,使用FreeSurfer软件自动评估与记忆功能密切相关的灰质区域的厚度和体积。然后,体积,分数各向异性(FA),平均扩散率(MD),使用SPM获得了白质高强度(WMH)区域和正常出现白质(NAWM)的低频波动幅度(ALFF)和区域均匀性(ReHo)值,DPARSF,和FSL软件。最后,协方差分析,采用spearman相关和中介分析进行数据分析。
■与NC组相比,SIVD-CI和SIVD-CU组患者表现出明显的异常体积,FA,MD,ALFF,以及WMH区域和NAWM的ReHo值,以及显著降低灰质区域的体积和厚度值,主要包括丘脑,颞中回和海马亚区,例如玉米角(CA)1。这些异常变化与视力下降显着相关,听觉和工作记忆得分。与SIVD-CU组相比,左侧CA2/3,右侧杏仁核的显着减少,在SIVD-CI组中发现了WMH区域和NAWM的右下和NAWM体积以及MD值显着增加。MD值的增加与工作记忆得分显著相关。此外,在SIVD-CI组中,CA1和丘脑体积的减少介导了WMH区异常微观结构指标与记忆评分降低之间的相关性。
■SIVD患者在WMH和NAWM中均有结构和功能损害,伴随着特定的灰质萎缩,这与记忆障碍密切相关,尤其是CA1萎缩和丘脑萎缩。更重要的是,某些时间区域的体积以及WMH区域和NAWM的MD值可能是区分SIVD-CI和SIVD-CU患者的潜在有用神经影像学指标.
UNASSIGNED: Prior MRI studies have shown that patients with subcortical ischemic vascular disease (SIVD) exhibited white matter damage, gray matter atrophy and memory impairment, but the specific characteristics and interrelationships of these abnormal changes have not been fully elucidated.
UNASSIGNED: We collected the MRI data and memory scores from 29 SIVD patients with cognitive impairment (SIVD-CI), 29 SIVD patients with cognitive unimpaired (SIVD-CU) and 32 normal controls (NC). Subsequently, the thicknesses and volumes of the gray matter regions that are closely related to memory function were automatically assessed using FreeSurfer software. Then, the volume, fractional anisotropy (FA), mean diffusivity (MD), amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) values of white matter hyperintensity (WMH) region and normal-appearing white matter (NAWM) were obtained using SPM, DPARSF, and FSL software. Finally, the analysis of covariance, spearman correlation and mediation analysis were used to analyze data.
UNASSIGNED: Compared with NC group, patients in SIVD-CI and SIVD-CU groups showed significantly abnormal volume, FA, MD, ALFF, and ReHo values of WMH region and NAWM, as well as significantly decreased volume and thickness values of gray matter regions, mainly including thalamus, middle temporal gyrus and hippocampal subfields such as cornu ammonis (CA) 1. These abnormal changes were significantly correlated with decreased visual, auditory and working memory scores. Compared with the SIVD-CU group, the significant reductions of the left CA2/3, right amygdala, right parasubiculum and NAWM volumes and the significant increases of the MD values in the WMH region and NAWM were found in the SIVD-CI group. And the increased MD values were significantly related to working memory scores. Moreover, the decreased CA1 and thalamus volumes mediated the correlations between the abnormal microstructure indicators in WMH region and the decreased memory scores in the SIVD-CI group.
UNASSIGNED: Patients with SIVD had structural and functional damages in both WMH and NAWM, along with specific gray matter atrophy, which were closely related to memory impairment, especially CA1 atrophy and thalamic atrophy. More importantly, the volumes of some temporomesial regions and the MD values of WMH regions and NAWM may be potentially helpful neuroimaging indicators for distinguishing between SIVD-CI and SIVD-CU patients.