Magnetic resonance imaging study of the gray matter changes in behavioral variant of frontotemporal dementia

目的 观察行为异常型额颞叶痴呆(behavioral variant of frontotemporal dementia,bvFTD)患者大脑灰质结构形态学的改变.方法 对39例很可能bvFTD患者(患者组)和性别、年龄与之相匹配的46名对照者(对照组)进行头部MRI扫描,采集高分辨率脑结构数据.采用神经精神问卷(Neuropsychiatric Inventory,NPI)、MMSE、韦氏记忆量表中文版逻辑记忆分测验、美国阿尔茨海默病联合登记协作组织结构性练习、WCST等对2组进行认知与精神行为评估.应用基于体素的形态测量学-李代数微分同胚配准算法(voxel-based morphometry and diffeomorphic anatomical registration through exponentiated lie algebra,VBM-DARTEL)比较2组脑结构差异,并采用偏相关分析全脑灰质体积与NPI总分之间的相关关系.结果 患者组精神行为(Z=-6.545)和总体认知功能(t=-8.621)评分以及执行功能(t=4.776)、情景记忆(t=-7.990)、视空间能力(Z=-4.909)评分均较对照组差异有统计学意义(均P<0.01).与对照组相比,患者组双侧前额叶、前颞叶、岛叶、皮质下结构等脑区灰质体积明显减小(t=4.89~10.95,P<0.05,FWE校正),且两侧半球相对对称,双侧尾状核、杏仁核、苍白球、壳核、岛叶、直回等脑区萎缩最为显著.偏相关分析显示,患者组位于左侧楔前叶的脑区(体素个数=193,峰值MNI坐标x=-7.5,y=-66.0,z=67.5)萎缩程度与NPI总分呈负相关(ρ=-0.515,P<0.05,AlphaSim校正).结论 bvFTD患者皮质-纹状体-丘脑-皮质神经环路结构异常,以双侧纹状体萎缩为著,左侧楔前叶萎缩程度与精神行为症状严重程度相关,双侧纹状体与左侧楔前叶萎缩可能为bvFTD潜在的早期诊断影像学标记物.Objective To investigate the brain gray matter atrophy in behavioral variant of frontotemporal dementia (bvFTD) in order to provide an objective basis for early diagnosis. Methods High-resolution 3D structural brain images of 39 probable bvFTD and 46 controls were acquired by 3.0 Tesla MRI scanner. Neuropsychiatric Inventory (NPI), MMSE, Logical Memory Subtest of the Wechsler Memory Scale-Chinese Revision, Consortium to Establish a Registry for Alzheimer''s Disease drawing and WCST were administered to assess cognitive function and psychological and behavioral symptoms. Then voxel-based morphometry and diffeomorphic anatomical registration through exponentiated lie algebra (VBM-DARTEL)was used to compare the structural difference between bvFTD and control groups. Partial correlation analysis was deployed to examine the relationship between the whole brain volume and the total score of the NPI. Results Compared with the control group, bvFTD patients showed abnormalities in most of the neuropsycological tests (all P<0.01), including the higher scores in NPI(Z=-6.545), and the poor performance in global cognitive function(t=-8.621), execution function(t=4.776), episodic memory (t=-7.990)and visuospatial skills(Z=-4.909). In addition, the volume of specific regions, including notably bilateral prefrontal and pre-temporal cortex, insula and subcortical structures, were significantly reduced in bvFTD group (t=4.89-10.95,P<0.05,FWE-corrected). Most prominent atrophy was observed in bilateral caudate nucleus, amygdala, pallidum, putamen, insula, and rectus gyrus. Moreover, the atrophy of left precuneus (cluster size=193 voxels, peak MNI coordinates x=-7.5, y=-66.0, z=67.5) was significantly associated with the total score of NPI (ρ=-0.515,P<0.05,AlphaSim corrected). Conclusions It indicates that the structure of cortico-striatal-thalamic circuits is compromised in bvFTD. The atrophy of bilateral striatum may be most prominent. Besides, the volume of left precuneus may be associated with the severity of psychological and behavioral symptoms. These findings suggest the atrophy of bilateral striatum and left precuneus might be considered as potential imaging markers of bvFTD.国家科技支撑计划项目; 国家自然科学基金(81171018, 81620108016) National Science and Technology Infrastructure Program; National Natural Science Foundation of China5352-3575