目的 对头颅MRI异常或正常的抗N-甲基-D-天冬氨酸受体（NMDAR）脑炎患儿进行对比研究。方法 回顾性分析33例抗NMDAR脑炎患儿的临床特点，并比较头颅MRI异常或正常患儿之间的临床特点及预后差异。结果 33例患儿发生率前5位的首发症状依次为癫癎发作（61%）、不自主运动（61%）、语言障碍（54%）、精神行为异常（52%）和意识障碍（30%）。所有患儿的脑脊液抗NMDAR抗体均阳性，29例（88%）血清抗体阳性。脑脊液白细胞升高的15例（46%），3例（9%）蛋白升高，寡克隆阳性29例（88%）。脑电图异常（癫癎波或慢波或合并存在）患儿26例（79%）。仅1例发生呼吸衰竭。1例在随诊过程中发现蝶鞍区生殖细胞瘤。33例患儿中头颅MRI异常的13例（39%）：T1WI表现为低信号或等信号、T2WI及T2-FLAIR表现为高信号，病变部位包括颞叶（38%）、额叶（23%）、基底节（23%）、顶叶（15%）、枕叶（15%）、脑干（15%）、丘脑和小脑（各8%），其中以灰质病变为主者5例（38%）、白质病变为主者8例（62%），2例患儿存在脑膜强化。头颅MRI异常患儿的前驱感染比例、意识障碍发生率、病情反复的几率、Glasgow严重评分、脑脊液白细胞升高发生率、二线治疗的应用率均高于头颅MRI正常的患儿，差异具有统计学意义（P < 0.05）。结论 头颅MRI异常的抗NMDAR脑炎患儿具有某些临床特点，这些特点对于病情的判断和诊疗措施的选择具有一定的指导意义。

Objective To investigate the clinical features of children with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis with normal or abnormal cranial magnetic resonance imaging (MRI) findings via a comparative analysis.Methods A retrospective analysis was performed for the clinical data of 33 children with anti-NMDAR encephalitis. The clinical features and prognosis were compared between the children with normal and abnormal cranial MRI findings.Results In the 33 children with anti-NMDAR encephalitis, the most common initial symptoms were seizures (61%) and involuntary movement (61%), followed by language disorder (54%), mental and behavioral abnormalities (52%), and disturbance of consciousness (30%). All children had positive anti-NMDAR antibody in the cerebrospinal fluid, and 29 children (88%) had positive serum antibody. Of all the children, 15 (46%) had increased leukocytes in the cerebrospinal fluid, 3 (9%) had an increase in protein, and 29 (88%) had positive oligoclonal band; 26 children (79%) had electroencephalographic abnormalities (epileptic wave, slow wave, or a combination of these two types of waves). One child experienced respiratory failure. One child was found to have germinoma in the sellar region during follow-up. Of all the 33 children, 13 (39%) had abnormal cranial MRI findings, with hypointensity or isointensity on T1W1 and hyperintensity on T2WI and T2-FLAIR; 2 children had dural enhancement. As for the location of lesion, 5 children (38%) had lesions in the temporal lobe, 3 (23%) in the frontal lobe, 3 (23%) in the basal ganglia, 2 (15%) in the parietal lobe, 2 (15%) in the occipital lobe, 2 (15%) in the brainstem, 1 (8%) in the thalamus, and 1 (8%) in the cerebellum. Among the 13 children with abnormal cranial MRI findings, 5 (38%) had lesions mainly in the grey matter and 8 (62%) had lesions mainly in the white matter. Compared with the children with normal cranial MRI findings, the children with abnormal cranial MRI findings had significantly higher proportion of children with prodromal infection, incidence rate of disturbance of consciousness, probability of recurrence, Glasgow score, incidence rate of increased leukocytes in the cerebrospinal fluid, and application rate of second-line treatment (P<0.05).Conclusions Children with anti-NMDAR encephalitis and abnormal cranial MRI findings have certain clinical features, which may provide guidance for the evaluation of disease conditions and the selection of diagnostic and treatment measures.