非痴呆型血管性认知功能障碍的结构及静息态功能磁共振研究

The Structure and Resting State Functional Magnetic Resonance Findings in Patients with Non-Dementia Vascular Cognitive Impairment

目的探讨结构及静息态功能磁共振在研究非痴呆型血管性认知障碍(VCIND)中的价值。方法搜集本院47例年龄、性别、受教育程度相匹配的脑小血管疾病患者,经临床痴呆及其他认知量表评分后,21例患者纳入VCIND组,26例认知功能正常者纳入对照组,采用Siemens 3.0 T超导MR仪采集高分辨率结构像和静息态功能磁共振数据,通过基于体素的形态学测量(VBM)及低频振幅(ALFF)分析方法计算并对比两组患者脑结构及脑功能活动的改变,通过与临床量表做相关分析,观察VCIND组ALFF统计脑图与量表评分的相关性。结果经过Alphasim校正,VCIND组较对照组在左侧颞下回及海马旁回出现灰质体积减少,差异有统计学意义(P<0.05)。与对照组相比,VCIND组在内侧前额叶、额下回ALFF减低,在双侧小脑出现ALFF增高,差异有统计学意义(P<0.05),回归灰质体积后,VCIND组较对照组ALFF改变的脑区较前相似,仅在左侧额中回新出现ALFF减低,差异有统计学意义(P<0.05)。VCIND组ALFF统计脑图与多个临床量表评分存在显著相关性,差异有统计学意义(P<0.05)。结论 VCIND患者较对照组仅部分脑区出现灰质萎缩,血管性认知功能障碍(VCI)患者认知功能损害可能与前额叶-皮层下环路受损有关,灰质萎缩对功能障碍存在较小的影响,VBM及ALFF在VCI及其早期诊断中有重要价值。

Objective To assess the value of the structure and resting state functional magnetic resonance in studying non-dementia vascular cognitive impairment （VCIND）. Methods A total of 47 patients with cerebral small vessel diseases, who were comparable in age, gender, education level, were collected. After evaluation with the clinical dementia criterion and other cognitive scale, 21 patients were enrolled into VCIND group, and 26 cases with normal cognitive functionwere classified in the control group. Using SIEMENS 3.0T superconducting MR scanner, high resolution structure images were obtained and resting state functional magnetic resonance data were colleted. By using voxel-based morphometry （VBM） and amplitude of low frequency fluctuation （ALFF） analysis method, the brain structures and the brain activity changes were compared between the two groups. The correlation between ALFF statistical map and the clinical scale scorein VCIND group was analyzed. Results Through aphasim correction, the volume of the gray matter in the left inferior temporal gyrus and parahippocampal gyrus in VCIND group was significantly reduced when compared with that in the control group （P 〈 0.05）. Compared with the control group, ALFF in VCIND group was decreased in medial prefrontal cortex and inferior frontal gyrus, while it was increased in bilateral cerebellum, and the differences were statistically significant （P 〈0. 05 ）. After regression of the gray matter volume, ALFF changes in VCIND group were similar to the previous changes, i. e. the reduction of ALFF appeared in the left middle frontal gyrus, and the difference was statistically significant （ P 〈 0.05）. In VCIND group close correlation existed between ALFF statistical brain maps and multiple clinical scale scores, and the differences were statistically significant （P 〈 0.05）. Conclusion Compared with the control group, in patients with non-dementia vascular cognitive impairment the brain gray matter atrophy is present only in small parts of the brain. The cognitive function impairment in patients with vascular cognitive impairment may be related to the damaged prefrontaland subcortical loop, and gray matter atrophy has little effect on cerebral dysfunction. Both VBM and ALFF play an impor- tant value in making early diagnosis of vascular cognitive impairment.