血管性认知障碍的脑白质微结构改变

Vascular cognitive impairment and changes in brain white matter microstructure

目的:利用基于纤维束示踪空间统计分析(TBSS)的DTI分析方法,评估血管性认知障碍(VCI)患者脑白质微结构的改变,并探讨其与认知能力的关系。方法:招募VCI患者(VCI组)和无认知障碍受试者(健康对照组)各20例,均行DTI扫描和认知评估量表检查。基于TBSS比较2组大脑各白质纤维束的各向异性分数(FA)和平均扩散率(MD)。使用Spearman相关分析评价DTI各参数的均值与认知评估结果间的关系。结果:VCI组脑白质微结构广泛受损,FA值下降,MD值升高,主要累及两侧大脑半球联络纤维、两侧丘脑前辐射、两侧额枕下束等;FA值与蒙特利尔认知评估量表(MoCA)评分呈正相关(r=0.671,P<0.001),MD值与MoCA评分呈负相关(r=-0.658,P<0.001)。结论:VCI患者存在广泛的白质微结构损伤,主要位于两侧大脑半球间联络纤维、两侧丘脑前辐射和两侧额枕下束。基于TBSS的DTI分析能更客观地对脑白质微结构变化进行定位和定量评价。

Objective:To evaluate the changes in brain white matter microstructure in patients with vascular cognitive impairment(VCI)by using DTI based on track-based spatial statistics(TBSS).To explored the relationship between DTI parameters and cognitive function.Methods:A total of 20 VCI patients and 20 healthy controls were recruited for DTI scanning and cognitive assessment.DTI data were processed based on TBSS,the fractional anisotropy(FA)and mean diffusivity(MD)of each white matter fiber bundle of the two groups were obtained and compared.Spearman correlation analysis was used to evaluate the relationship between DTI parameters and cognitive assessment.Results:There were extensive white matter microstructure damage in VCI patients,including decreased FA values and increased MD values,mainly involving the connecting fibers of the bilateral cerebral hemispheres,bilateral anterior thalamic radiation and bilateral inferior fronto-occipital fasciculus.The FA value was positively correlated with the Montreal Cognitive Assessment(MoCA)score(r=0.671,P<0.001),and the MD value was negatively correlated with the MoCA score(r=-0.658,P<0.001).Conclusions:VCI patients exhibited extensive white matter microstructure damage,mainly involving connecting fibers of the bilateral cerebral hemispheres,bilateral anterior thalamic radiation and bilateral inferior fronto-occipital fasciculus.DTI analysis based on TBSS allows for a more objective localization and quantification of the changes in white matter microstructure.