遗忘型轻度认知障碍患者脑灰质体积变化与认知和步态障碍的相关性研究

The correlation among altering gray matter volume,cognition and gait disorder in patients with amnestic mild cognitive impairment

目的探讨遗忘型轻度认知障碍(aMCI)患者脑灰质体积变化与认知和步态障碍的相关性。方法收集2018年7月至2020年8月安徽医科大学第一附属医院收治的aMCI患者36例,同期纳入年龄、性别、教育程度匹配的正常对照33名。采用简易精神状态检查(MMSE)、蒙特利尔认知评估量表(MoCA)、剑桥认知检查量表中文版(CAMCOG-C)、日常生活能力量表(ADL)、老年抑郁量表(GDS)等对受试者进行神经心理学评估。评估受试者起立行走测试(TUG)、起立行走双重任务测试(D-TUG)和Berg平衡量表(BBS)测评结果;使用智能能量消耗和日常活动记录仪采集受试者步长、步速、步频。对受试者均进行3.0 T磁共振成像扫描,获取高分辨T1结构像。使用基于体素的形态学测量法(VBM)比较aMCI患者与正常对照之间灰质体积的差异。将差异脑区灰质体积分别与认知评分、步态参数进行偏相关分析;认知评分与步态进行偏相关分析;全脑灰质体积与步态进行线性回归分析。结果aMCI组MMSE、MoCA、CAMCOG-C总分及分项目评分均显著低于正常对照组(均P<0.05)。aMCI组TUG、D-TUG时长增加,步速减慢,步长缩短,BBS评分降低,步频减少(均P<0.05)。VBM分析结果显示aMCI组全脑灰质体积较正常对照组减小,aMCI组在感兴趣区1(包括右侧海马、右侧海马旁回、右侧杏仁核等)、感兴趣区2(右侧颞中回)、感兴趣区3(右侧顶下缘角回)、感兴趣区4(右侧枕叶)、感兴趣区5(双侧眶部额叶)、感兴趣区6(左侧额中回、直回)、感兴趣区7(左侧梭形回、左侧海马旁回等区域)等部位灰质体积较正常对照组显著减小[高斯随机场(GRF)校正,双侧检验,体素水平P<0.001,团块水平P<0.05]。aMCI组中感兴趣区1灰质体积与定向(r=0.437,P=0.012)、记忆(r=0.360,P=0.043)、执行(r=0.414,P=0.019)等评分呈正相关,与ADL评分呈负相关(r=-0.529,P=0.002);感兴趣区2灰质体积与ADL评分呈负相关(r=-0.400,P=0.023);感兴趣区4灰质体积与计算评分呈正相关(r=0.370,P=0.037);感兴趣区5灰质体积与执行评分呈正相关(r=0.360,P=0.043);感兴趣区6灰质体积与MMSE评分(r=0.357,P=0.045)、CAMCOG-C总分(r=0.503,P=0.003)、计算评分(r=0.395,P=0.025)呈正相关,与ADL评分(r=-0.387,P=0.028)呈负相关。aMCI组感兴趣区5灰质体积与步速呈正相关(r=0.391,P=0.027)。aMCI组CAMCOG-C评分与D-TUG时长呈负相关(r=-0.387,P=0.035);执行功能评分与TUG(r=-0.450,P=0.013)、D-TUG时长(r=-0.553,P=0.002)呈负相关,与步速(r=0.379,P=0.039)呈正相关;注意评分与步速(r=0.590,P=0.001)呈正相关;计算评分与步速(r=0.371,P=0.044)呈正相关。aMCI组中左侧枕上回灰质体积与TUG时长呈负相关;双侧额叶直回、右眶部额中回、右侧距状裂、右侧枕上回、左侧中央前回等灰质体积与步速呈正相关(GRF校正,双侧检验,体素水平P<0.001,团块水平P<0.05)。结论aMCI患者出现灰质萎缩、认知功能下降及步态障碍;认知功能下降与内侧颞叶的萎缩密切相关;步态障碍不仅与认知功能相关还与前额叶、枕叶及其周围皮质、中央前回等部位灰质体积相关。

Objective To investigate the impact of altering brain gray matter volume(GMV)on cognition and gait disorder in patients with amnestic mild cognitive impairment(aMCI).Methods Thirty-six patients with aMCI,who admitted to the First Affiliated Hospital of Anhui Medical University from July 2018 to August 2020,were collected,and 33 normal controls(NC)matched with age,sex and education level were included in the same period.The neuropsychological assessment was done in all the subjects using Mini-Mental State Examination(MMSE),Montreal Cognitive Assessment scale(MoCA),Cambridge Cognitive Examination-Chinese version(CAMCOG-C),Geriatric Depression Scale(GDS)and Activities of Daily Living scale(ADL).The timed up and go test(TUG),dual task of timed up and go test(D-TUG)and Berg Balance Scale(BBS)were used in the subjects for assessment.The parameters such as stride length,gait speed,gait frequency were collected by intelligent device for energy expenditure and activity.All the subjects received 3.0 T magnetic resonance imaging scan to obtain high-resolution T1 structural images.Voxel-based morphometry(VBM)was used to compare the difference of GMV between aMCI patients and NC.Partial correlation analysis was performed among altering GMV in the regions of interest(ROI),cognitive score and gait parameters,respectively.Linear regression analysis was used between whole brain GMV and gait parameters.Results The scores of MMSE,MoCA,CAMCOG-C and the subitems of CAMCOG-C in aMCI group were significantly lower than those in NC group(P<0.05).In aMCI patients,both the test time of TUG and D-TUG increased,gait speed slowed down,stride length shortened,and stride frequency and BBS score decreased(P<0.05).VBM analysis showed that the whole brain GMV in aMCI patients was obviously lower than that of NC.In the aMCI group,GMV in ROI1(right hippocampus,right parahippocampal gyrus,right amygdala and right fusiform gyrus),ROI2(right middle temporal gyrus),ROI3(right angular gyrus),ROI4(right occipital lobe),ROI5(bilateral orbital frontal lobe),ROI6(left middle frontal gyrus and rectus gyrus),ROI7(left fusiform gyrus and left parahippocampal gyrus)was significantly decreased compared with the NC group[Gaussian random field(GRF)correction,two-tailed test,voxel level P<0.001,cluster level P<0.05).In the aMCI group,GMV in ROI1 was positively correlated with orientation(r=0.437,P=0.012),memory(r=0.360,P=0.043),execution(r=0.414,P=0.019),and negatively correlated with ADL score(r=-0.529,P=0.002).GMV in ROI2 was negatively correlated with ADL score(r=-0.400,P=0.023).GMV in ROI4 and in ROI5 was positively correlated with the calculation(r=0.370,P=0.037)and execution(r=0.360,P=0.043),respectively.GMV in ROI6 was positively correlated with MMSE score(r=0.357,P=0.045),CAMCOG-C total score(r=0.503,P=0.003)and calculation(r=0.395,P=0.025),and negatively correlated with ADL score(r=-0.387,P=0.028).GMV in ROI5 was positively correlated with gait speed(r=0.391,P=0.027).In the aMCI group,CAMCOG-C total score was negatively correlated with D-TUG results(r=-0.387,P=0.035),executive function was negatively correlated with TUG results(r=-0.450,P=0.013)and D-TUG results(r=-0.553,P=0.002),and positively correlated with gait speed(r=0.379,P=0.039).Attention was positively correlated with gait speed(r=0.590,P=0.001),and computing was positively correlated with gait speed(r=0.371,P=0.044).The linear regression of whole brain GMV and gait parameters showed negative correlation between the GMV of left occipital lobe and TUG results in the aMCI group.The GMV of bilateral prefrontal cortex,right occipital lobe and surrounding cortex was positively correlated with gait speed(GRF correction,two-tailed test,voxel level P<0.001,cluster level P<0.05).Conclusions Patients with aMCI presented with gray matter atrophy,cognition impairment,and gait disorders.The cognition impairment was closely related to the atrophy of medial temporal lobe.Gait disorders were not only associated with cognition impairment but also with gray matter volume in the prefrontal lobe,occipital lobe and its surrounding cortex,and anterior central gyrus.