Fu Jian-Liang, Liu Yu, Li Yu-Mei, Chang Cheng, Li Wen-Bin
Department of Neurology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, 200233, P. R. China.
J Neuroimaging. 2014 Jul-Aug;24(4):343-8. doi: 10.1111/jon.12061. Epub 2013 Nov 19.
Patients with amnestic mild cognitive impairment (aMCI) are at risk of developing Alzheimer's disease (AD). It is therefore important to identify biomarkers of conversion to AD. This study examined whether the integrity of white matter can predict this conversion.
Magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and neuropsychological features of aMCI subjects (n = 41) were compared with normal controls (n = 20) for 12-36 months.
Compared to controls, 22 aMCI subjects had lower fractional anisotropy (FA) values in the cingulate fasciculus (CF) at baseline, and 19 of those converted to AD during follow-up. Only two of the other 19 aMCI patients converted to AD. Compared to baseline, AD converters showed lower FA values in the anterior frontal lobe, temporal lobe, hippocampus, inferior fronto-occipital fascicles, corpus callosum genu and CF, and higher apparent diffusion coefficient values in the temporal lobe and hippocampus.
Those aMCI subjects with lower than normal FA values in the CF were more likely to convert to AD. The connectivity of the hippocampus and cingulate bundles may be affected in the early stage of AD. Impairment of white matter and fiber bundles was more severe at the AD stage than the aMCI stage.
遗忘型轻度认知障碍（aMCI）患者有患阿尔茨海默病（AD）的风险。因此，识别向AD转化的生物标志物很重要。本研究探讨白质完整性是否能预测这种转化。
对41例aMCI受试者和20例正常对照者进行了12至36个月的磁共振成像（MRI）、扩散张量成像（DTI）及神经心理学特征比较。
与对照组相比，22例aMCI受试者在基线时扣带束（CF）的分数各向异性（FA）值较低，其中19例在随访期间转化为AD。其他19例aMCI患者中只有2例转化为AD。与基线相比，AD转化者在前额叶、颞叶、海马、额枕下束、胼胝体膝部和CF的FA值较低，在颞叶和海马的表观扩散系数值较高。
CF中FA值低于正常的aMCI受试者更有可能转化为AD。海马和扣带束的连接性可能在AD早期受到影响。白质和纤维束的损伤在AD阶段比aMCI阶段更严重。
