磁共振扩散张量成像定量评估肌萎缩侧索硬化症患者上运动神经元病变的意义(英文)

Significance of magnetic resonance diffusion tensor imaging for evaluation of upper motor neuron disease in patients with amyotrophic lateral sclerosis

背景:磁共振扩散成像可以无创检测白质纤维的损害,使其可能成为一种有效评价肌萎缩侧索硬化患者上运动神经元损害的方法。目的:探讨磁共振扩散张量成像在肌萎缩侧索硬化症中的临床意义。设计:病例-对照观察。单位:武汉大学人民医院神经科。对象:选择2005-04/12武汉大学人民医院神经科收治的20例确诊及疑似肌萎缩侧索硬化症患者,男11例,女9例,年龄33～73岁,平均(51±10)岁。均符合世界神经病学联盟肌萎缩侧索硬化症诊断标准。选择15名到院健康体检的志愿者作为对照组,男8名,女7名,年龄31￣73岁,平均(50±11)岁。所有受试对象均对检测项目知情同意。方法:根据上、下运动神经元损害情况将确诊及疑似肌萎缩侧索硬化症患者分为上运动神经元损害组(n=16)及下运动神经元组(n=4),分别进行肌萎缩侧索硬化症功能评分、病情进展速度评估和锥体束征评分。所有受试对象均进行轴位DTI扫描,选取感兴趣区(中央前、后回皮质下白质、额叶白质、半卵圆中心、侧脑室周围、内囊后肢、大脑脚、胼胝体压部、膝部、丘脑)测量各向异性分数和平均扩散系数。主要观察指标:各感兴趣区各向异性分数和平均扩散系数及与肌萎缩侧索硬化症功能评分、病情进展速度、锥体束征评分的关系。结果:纳入患者20例及对照组15名均进入结果分析。①上运动神经元损害组患者内囊后肢各向异性分数较对照组降低,平均扩散系数增大,差异有显著性意义(t=3.452,2.670,P<0.01,0.05),下运动神经元损害组患者内囊后肢水平各向异性分数较对照组降低(U=11,P=0.057)。②上运动神经元损害组内囊后肢水平各向异性分数与肌萎缩侧索硬化功能评分呈正相关(r=0.577,P<0.05),与锥体束征评分呈负相关(r=-0.789,P<0.01)。结论:磁共振扩散张量成像可客观而定量评价锥体束病变,为肌萎缩侧索硬化症的诊断提供有价值的信息。

BACKGROUND ： Magnetic resonance diffusion tensor imaging （MRDTI） may non-wounded detect damage of fiber in white matter and becomes an effectively way to evaluate upper motor neuron（UMN） impairments. OBJECTIVE： To investigate the clinical significance of MRDTI on amyotrophic lateral selerosis（ALS）. DESIGN ： Case contrast observation . SETTING ： Department of Neurology, Renmin Hospital of Wuhan University. PARTICIPANTS： Twenty ALS patients were selected from Department of Neurology, Renmin Hospital of Wuhan University from April to December 2005. There were 11 males and 9 females, and their ages ranged from 33 to 73 years with the mean age of （51±10） years. All subjects met the diagnostic criteria of ALS set by World Neurology League. Other 15 healthy subjects were collected as control group. There were 8 males and 7 females, and their ages ranged from 31 to 73 years with mean age of （50±11） years. All subjects provided the confirm consent. METHODS： Based on level of upper and lower motor neuron impairments, ALS patients were divided into UMN impairment group （n =16） and lower motor neuron group （n =4）. Functional scores of ALS, illness developing velocity and pyramidal sign scores were performed, respectively. All subjects were scanned with DTI at axial view. Regions of interest [subcortical white matter of precentral gyrul and postcentral gyrul （Pre-CG/Post-CG）, centrum semiovale and frontal white matter （CS/FWM）, peripheral lateral cerebral ventricle, posterior limb of internal capsule （PIC）, cerebral peduncle （CP）, genu corpus callosum and splenium corpus callosum （GCC/SCC） and dorsal thalamus （DT）] were selected to measure fractional anisotropy （FA） and apparent diffusion coefficient（ADC）. MAIN OUTCOME MEASURES ： Correlations among FA, ADC, functional score of ALS, illness developing velocity and pyramidal sign scores. RESULTS： Twenty patients and 15 subjects in the control group were involved in the final analysis. ① FA was reduced and ADC increased in the posterior limb of the internal capsule in patients with UMN signs compared to healthy volunteers （t =3.452, 2.670; P 〈 0.01, 0.05）. Nonparametric tests revealed that there was a trend toward reduced FA in the posterior limb of the internal capsule in B group compared to controls （U =11, P =0.057）. ② In UMN impairment group, FA in the posterior limb of the internal capsule was positively correlated with the ALS rating scale （r =0.577, P 〈 0.05） and negatively correlated with pyramidal.sign scores （r = -0.789, P 〈 0.01）. CONCLUSION ： The impairment of pyramidal tracts can be noninvasively evaluated by diffusion tensor MR in vivo, thus providing useful information in diagnosing and further understanding MND.