1H-MR波谱分析急性期抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎额叶代谢物变化

目的 采用¹H-MR波谱（¹H-MRS）观察急性期抗N-甲基-D-天冬氨酸受体（NMDAR）脑炎双侧额叶代谢物变化及其与认知障碍的关系，评估其应用价值。方法 采集20例急性期抗NMDAR脑炎患者（脑炎组）和20名健康成年人（对照组）双侧额叶¹H-MRS，获得相应MRS及各代谢物N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌醇（mI）、谷氨酸盐复合物（Glx）和肌酸（Cr）的峰下面积，计算NAA/Cr、Cho/Cr、mI/Cr及Glx/Cr比值。记录脑炎组脑脊液抗NMDAR抗体滴度检测结果，以简易精神状态检查量表（MMSE）和蒙特利尔认知评估（MoCA）量表评估2组认知功能，比较组间¹H-MRS参数差异，并分析其与抗NMDAR脑炎患者MMSE评分、MoCA评分及与脑脊液抗NMDAR抗体的相关性。结果 脑炎组双侧额叶NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr差异均无统计学意义（t=1.03、2.29、－0.73、0.15，P均>0.05）。与对照组相比，脑炎组双侧额叶NAA/Cr下降、Glx/Cr升高（P均<0.05），而双侧额叶Cho／Cr、mI/Cr差异均无统计学意义（P均>0.05）。脑炎组双侧额叶NAA/Cr、Cho/Cr、mI/Cr及Glx/Cr与MMSE评分、MoCA总分和脑脊液抗NMDAR抗体均无明显相关性（P均>0.05）。结论 ¹H-MRS有助于诊断急性期抗NMDAR脑炎及监测病情；抗NMDAR脑炎急性期双侧额叶NAA/Cr降低、Glx/Cr升高，但与认知障碍无明显相关。

1H-MR spectroscopy in analysis of frontal lobe metabolism changes of acute anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis

Objective To observe bilateral frontal lobe metabolism changes of acute anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis with ¹H-MR spectroscopy (¹H-MRS) and the relationships with cognitive impairment, and to evaluate the application value of ¹H-MRS in treatment of this disease. Methods ¹H-MRS of bilateral frontal lobes of 20 patients with acute anti-NMDAR encephalitis (encephalitis group) and 20 healthy adults (control group) were collected to obtain the corresponding MRS and subpeak areas of the metabolites N-acetylaspartate (NAA), choline (Cho), myoinositol (mI), glutamine+glumate (Glx) and creatine (Cr) in bilateral frontal cortex. The ratios of NAA/Cr, Cho/Cr, mI/Cr and Glx/Cr were calculated. The results of cerebrospinal fluid anti-NMDAR antibody in encephalitis group were collected. Cognitive functions were assessed using mini-mental state examination (MMSE) and montreal cognitive assessment (MoCA) scales and compared between groups. MRS results were compared between groups, and the relationships with MMSE and MoCA scores and cerebrospinal fluid anti-NMDAR antibody level in encephalitis patients were analyzed. Results There was no significant difference of NAA/Cr, Cho/Cr, mI/Cr and Glx/Cr of bilateral frontal lobes in encephalitis group (t=1.03, 2.29, -0.73, 0.15, all P>0.05). Compared with those in control group, the ratio of NAA/Cr decreased and Glx/Cr increased in bilateral frontal lobes in encephalitis group (all P<0.05), while there was no significant difference of Cho/Cr nor mI/Cr of bilateral frontal lobes (all P>0.05). No significant correlation of the ratios of NAA/Cr, Cho/Cr, mI/Cr, Glx/Cr, MMSE, MoCA scores nor of cerebrospinal fluid anti-NMDAR antibody levels was found in encephalitis group (all P>0.05). Conclusion ¹H-MRS was helpful to diagnosing and monitoring the development of acute anti-NMDAR encephalitis. NAA level decreased and Glx level increased in bilateral frontal cortex in acute anti-NMDAR encephalitis, but there was no significant correlation between the changes of bilateral frontal cortex metabolites and cognitive impairment.