脑白质疏松症患者磁共振波谱成像的特点及其与认知功能损害的关系

Characteristics of magnetic resonance spectroscopy imaging in patients with leukoaraiosis and its relationship with cognitive impairment

目的探讨脑白质疏松症(leukoaraiosis,LA)患者认知功能损害的特点及其不同脑区磁共振波谱(magnetic resonance spectroscopy,MRS)NAA/Cr、Cho/Cr、NAA/Cho值的变化特点,并研究两者的相关性。方法选择2016-06~2017-06就诊于山西省人民医院,经头颅核磁共振成像(magnetic resonance imaging,MRI)检查诊断为LA的患者40例为病例组,头颅MRI表现正常的老年人20例为对照组。采用神经心理量表评价LA患者不同认知域的损害,并进行MRS检查,比较病例组与对照组在脑不同感兴趣区(region of interest,ROI)的NAA/Cr、Cho/Cr、NAA/Cho值。结果与对照组比较,LA患者整体认知功能下降,且存在执行功能、记忆力、信息处理能力、视空间技能的下降(P<0.05),表现为MMSE、MoCA得分下降,数字广度逆序、词语流畅性测试(verbal fluency test,VFT)、词语相似性测验、记忆力测试、画钟试验、积木试验得分较低,StroopC、连线测试(trail making test,TMT)A、StroopB用时较长,差异有统计学意义(P<0.05)。LA患者半卵圆中心、颞叶海马、双侧前额叶的NAA/Cho值与NAA/Cr值,侧脑室前角的NAA/Cho值,胼胝体膝部的NAA/Cr值较正常对照组显著下降,差异有统计学意义(P<0.05)。Stroop色词干扰试验B、C部分测试与半卵圆中心、侧脑室前角、颞叶海马、额叶、胼胝体膝部代谢值呈负相关(P<0.05);而数字广度逆序、延迟记忆、积木试验测试与各脑区的代谢值呈正相关(P<0.05);LA分级越重,NAA/Cr、NAA/Cho值越低,以双侧前额部最为显著,差异有统计学意义(P<0.05)。结论LA患者脑区存在脑代谢异常,且与认知减退相关。MRS检查有助于早期诊断LA患者的认知损害。

Objective To study the characteristics of cognitive impairment in leukoaraiosis(LA)patients and the changes of NAA/Cr,Cho/Cr,NAA/Cho in different brain regions using magnetic resonance spectroscopy(MRS),and to analyze their relationship.Methods Forty LA patients diagnosed by MRI in Shanxi Provincial People’s Hospital from June 2016 to June 2017 and 20 elderly normal controls were enrolled in this study.The impairment of different cognitive domains was measured by neuropsychometric questionnaires,and MRS was performed.The values of NAA/Cr,Cho/Cr and NAA/Cho in various regions of interest(ROI)were compared between two groups.Results Compared with controls,the overall cognitive functions decreased significantly in LA patients,and the executive function,memory,information processing capability,visual-spatial ability were damaged(P<0.05),including lower scores in mini mental state examination(MMSE)and Montreal cognitive assessment(MoCA),poorer scores in digit span(DS)-inverted sequence,verbal fluency test(VFT),word similarity test,memory test,clock drawing test and block testing,and longer time of Stroop test C,trail marking test A(TMTA)and Stroop test B(P<0.05).The NAA/Cho and NAA/Cr values in the centrum semiovale,the temporal lobe hippocampal and bilateral profrontal lobe,the NAA/Cho values in anterior horn of lateral ventricle,the NAA/Cr values in genu of corpus callosum were significantly decreased in LA group compared with control group(P<0.05).Stroop test B and stroop test C scores were negatively correlated with metabolic values in centrum semiovale,anterior horn of lateral ventricle,temporal lobe hippocampal,frontal lobe,and genu of corpus callosum(P<0.05).Digit span(DS)-inverted sequence,delayed memory and block testing were positively related with various brain regions(P<0.05).The more serious LA grade was,the lower NAA/Cr,NAA/Cho value was,especially in the bilateral profrontal lobe(P<0.05).Conclusion LA patients have abnormal brain metabolism in brain regions,and it is related to cognitive impairment.MRS can contribute to early diagnosis of cognitive impairment in LA patients.