缺血性脑白质病变伴轻度认知功能障碍患者记忆障碍的静息态功能磁共振成像

目的探讨缺血性脑白质病变伴轻度认知功能障碍患者的记忆损害特征及其与静息态功能磁共振成像(rsfMRI)改变的关系。方法收集缺血性脑白质病变伴轻度认知障碍患者15例(vMCI组)及健康老年志愿者15名(对照组),采用听觉词语学习测验(AVLT)分析记忆功能,采用rs-fMRI分析脑静息态低频波动振幅(ALFF),比较两组记忆评分差异,并与ALFF进行相关分析。结果 vMCI组蒙特利尔认知评估量表(MoCA)、简明精神状态检查量表(MMSE)、短时记忆(STM)评分均低于对照组(P均<0.05)。两组在额顶枕叶和皮质下区域存在广泛异常的自发脑活动。去除年龄、性别和教育程度的影响后,偏相关分析显示,vMCI组双侧壳核ALFF与STM评分呈负相关,左侧楔叶ALFF与MoCA评分呈负相关,左侧额上回/辅助运动区(SMA)与MoCA评分呈正相关,左侧额内侧回/SMA及右侧壳核与MMSE评分呈正相关(P均<0.05)。结论缺血性白质病变伴轻度认知功能障碍患者记忆损害主要表现为短时记忆减退,机制可能与多个脑区功能异常有关,双侧壳核代偿为主要特点。

Resting-state functional MRI in memory deficit of patients with ischemic white matter lesions and mild cognitive impairment

Objective To investigate the memory deficit in ischemic white matter lesions with mild cognitive impairment patients, and its relationship with resting-state functional magnetic resonance imaging (rs-fMRI). Methods Fifteen ischemic white matter lesions with mild cognitive impairment patients (vMCI group) and 15 normal controls (control group) were collected. Auditory verbal learning test (AVLT) was used to assess the memory function, and amplitude of low-frequency fluctuation (ALFF) was evaluated through rs-fMRI. The memory scores were compared between the two groups, and the correlations with ALFF were analyzed. Results Compared with control group, Montreal cognitive assessment (MoCA), mini-mental state examination (MMSE) and short time memory (STM) scores decreased in vMCI group (all P<0.05). There were widespread abnormal spontaneous activities in frontal- parietal-occipital lobe. Removing the influence of age, gender and education level, the partial correlation analysis indicated that the mean ALFF values of bilateral putamen were negativly correlated with STM in vMCI group. Moreover, negative correlation was found in the left cuneus between ALFF and MoCA, and positive correlation in the the left superior frontal gyrus/supplementary motor area (SMA). Positive correlation was still found in the left medial frontal gyrus/SMA and right putamen between ALFF and MMSE. Conclusion STM is the main memory deficit in patients of ischemic white matter lesions with mild cognitive impairment. It may be associated with multiple brain dysfunction. And bilateral putamen compensation is the main characteristics.