无痴呆型血管性认知障碍患者多体素质子磁共振波谱的诊断价值

A study of multi-voxel ^1H-magnetic resonance spectroscopy in patients with vascular cognitive impairment no dementia

目的探讨多体素质子磁共振波谱（^1H—MRS）在无痴呆型血管性认知障碍（VCIND）早期诊断中的价值。方法入选2008年12月至2009年9月本院门诊及住院患者共78例，完成成套神经心理学测验，包括北京版蒙特利尔认知量表（MoCA）、听觉词语学习测验（AVLT）、数字广度测验（DST）、Rey—Osterrieth复杂图形测验（CFT）、语义与语音流畅试验、数字符号编码测验（DSCT）、连线测验（TMT）、画钟测验（CDT）和Stroop色词测验（SCWT）。根据测验成绩分为VCIND组和认知正常对照组，从中选择性别、年龄、文化程度匹配者各18例，利用多体素。H-MRS检测双侧额、颞、顶叶及丘脑灰质区N-乙酰天冬氨酸（NAA）、肌酸（Cr）、胆碱（Cho）水平，比较两组间NAA／Cr、Cho／Cr比值的差别；同时，对VCIND组患者MoCA总分及其有认知损害的子项评分与NAA／Cr、Cho／Cr比值进行相关分析。所有入选对象对试验方案均知情同意，本试验通过伦理委员会批准。结果VCIND组患者左、右两侧丘脑灰质区NAA／Cr比值与对照组比较均明显下降（左侧1．56±0．49、1．89±0．48，F＝11．222，P=0．002；右侧1．63±0．45、1．86±0．33，F=5．358，P=0．027）；两组间额、颞、顶叶NAA／Cr比值以及所有区域Cho／Cr比值均无统计学意义。VCIND组患者左、右两侧NAA／Cr下降程度与MoCA评分（r=0．54、0．44）及记忆力（r=0．61、0．49）、注意力（r=0．43、0．36）、语言功能（r=0．39、0．31）、视空间与执行能力（r=0．29、0．33）等子项评分均呈正相关（均P〈0．05或P〈0．01）。结论VCIND患者认知功能损害可能与双侧丘脑神经元代谢异常有关，多体素^1H-MRS在VCIND早期诊断和病情进展监测中起着重要的作用。

Objective To evaluate the roles of muhi-voxel proton magnetic resonance spectroscopy （^1H-MRS） in the early diagnosis of vascular cognitive impairment no dementia （VCIND）. Methods Seventy-eight out-patients and inpatients in Department of Neurology, the second Affiliated Hospital of Soochow University from December 2008 to September 2009 were recruited in this case-control study. Their cognitive functions were assessed with a wide range of neuropsychological battery of tests including Montreal cognitive assessment （ MoCA Beijing Version ）, auditory verbal learning test （AVLT） , digital span test （DST）, Rey-Osterrieth complex figure test （CFT）, semantic and phonetic fluency tests, digit symbol coding subtest （DSCT）, trail making test （TMT）, clock drawing test （CDT） and the Stroop color-word test （SCWT）. All patients were classified into vascular cognitive impairment no dementia （VCIND） group and cognitive normal control group based on the results of neuropsychological tests. Eighteen patients with VCIND and 18 gender-, age- and education-matched normal control were randomly selected for the following study. With multi-voxel 1H-MRS, the levels of N-acetylaspartartate （NAA）, creatine （Cr） and choline （Cho） in gray matters of bilateral frontal lobe, temporal lobe, parietal lobe and thalamus were measured and the ratios of NAA/Cr, Cho/Cr were compared between the two groups. Meanwhile, the correlations between scores of MoCA and its sub-items and the ratios of NAA/Cr, Cho/Cr were analyzed in VCIND group. Informed consent was obtained from all participants and the study was approved by the Ethics Committee of the hospital. Results Compared with control group, the ratios of NAA/Cr were significantly decreased in bilateral gray matters of thalamus （ left, 1.56 ±0. 49 vs 1.89 ± 0. 48, F = 11. 222, P = 0. 002 ; right, 1.63 ± 0.45 vs 1.86± 0. 33, F = 5. 358, P = 0. 027 ）. No significant difference were found in NAA/Cr in gray matters of bilateral frontal lobe, temporal lobe, parietal lobe and Cho/Cr in all regions between two groups （ all P 〉 0. 05 ）. In VCIND group, the decreased degree of NAA/Cr in bilateral gray matters of thalamus was significantly positively correlated with the MoCA total score （ r = 0. 54, 0.44 ） as well as the sub-scores in tested items of memory （ r = 0. 61, 0. 49 ）, attention （ r = 0. 43, 0. 36 ）, language （ r = 0. 39, 0. 31） and visuospatial or executive （ r = 0. 29 , 0.33, allP〈0.05 or P〈0.01）. Conclusions Cognitive impairment in patients with VCIND maybe related to metabolic dysfunction of neurons in bilateral thalamic. Multi-voxel ^1H-MRS plays an important role in early diagnosis and monitoring disease progression of VCIND.