Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
Brain Dev. 2022 Jun;44(6):405-409. doi: 10.1016/j.braindev.2022.03.001. Epub 2022 Mar 26.
Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis characterized by complex neuropsychiatric syndromes and the presence of cerebrospinal fluid (CSF) antibodies against NMDAR. The characteristics of anti-NMDAR encephalitis in children, particularly infants, are unclear due to difficulties in neurologic assessment such as psychiatric symptoms. Additionally, subtle or non-specific findings of conventional magnetic resonance imaging (MRI) make early diagnosis even more difficult. Herein, we present the first case of infant anti-NMDAR encephalitis in which perfusion imaging demonstrated marked abnormalities and the absence of conventional MRI findings.
The patient was an 11-month-old boy who was admitted because of seizure and prolonged fever. He presented with involuntary movements of the mouth and tongue. Brain MRI showed no morphological abnormalities, but three-dimensional arterial spin labeling (ASL) perfusion imaging showed reduced blood flow in the left temporal and frontal regions and the right cerebellum. After that, a positive anti-NMDAR antibody test result was received. Despite treatment with IVIG and methylprednisolone, the involuntary movements and autonomic dysfunction gradually became more prominent. After rituximab administration, the clinical symptoms improved slightly, and follow-up MRI revealed diffuse brain atrophy and improvement in the balance of brain perfusion.
To the best of our knowledge, this is the first case report of infantile anti-NMDAR encephalitis in which cerebral blood flow was evaluated using three-dimensional ASL perfusion imaging. Indeed, our case, which showed abnormalities only in ASL perfusion imaging, suggests that CBF assessment could aid in the early diagnosis of anti-NMDAR encephalitis in infants.
抗 N-甲基-D-天冬氨酸受体（NMDAR）脑炎是一种自身免疫性脑炎，其特征为复杂的神经精神综合征和存在针对 NMDAR 的脑脊液（CSF）抗体。由于神经评估困难，如精神病症状，儿童，尤其是婴儿抗 NMDAR 脑炎的特征尚不清楚。此外，常规磁共振成像（MRI）的细微或非特异性发现使得早期诊断更加困难。在此，我们报告首例婴儿抗 NMDAR 脑炎病例，该病例的灌注成像显示明显异常且缺乏常规 MRI 发现。
患者为 11 月龄男婴，因抽搐和持续性发热入院。他表现为口和舌的不自主运动。脑部 MRI 未见形态学异常，但三维动脉自旋标记（ASL）灌注成像显示左侧颞叶和额叶以及右侧小脑血流量减少。之后，收到了抗 NMDAR 抗体检测阳性结果。尽管接受了 IVIG 和甲基强的松龙治疗，但不自主运动和自主神经功能障碍逐渐变得更加明显。利妥昔单抗治疗后，临床症状略有改善，随访 MRI 显示弥漫性脑萎缩和脑灌注平衡改善。
据我们所知，这是首例使用三维 ASL 灌注成像评估婴儿抗 NMDAR 脑炎脑血流的病例报告。事实上，我们的病例仅在 ASL 灌注成像中显示异常，这表明 CBF 评估可以帮助早期诊断婴儿抗 NMDAR 脑炎。
