Cerebellar ataxia is an atypical presentation of anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. In patients with anti-NMDAR encephalitis, cerebellar ataxia often develops simultaneously or sequentially with clinical features of demyelinating disorders, paraneoplastic neurologic syndromes, despite unremarkable brain magnetic resonance imagerying (MRI) findings. Herein, we report a patient with anti-NMDAR encephalitis who developed dizziness and gait ataxia as the initial symptoms, simultaneously showing MRI hyperintensities involving the cerebellum, even before manifesting behavioral and cognitive symptoms. We excluded the co-occurrence of other autoantibodies using cell- and tissue-based assays to establish a confirmed diagnosis of definite anti-NMDAR encephalitis.

中文翻译：

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抗NMDAR脑炎患者以小脑病变为首发症状的小脑性共济失调：罕见病例报告及文献复习

小脑性共济失调是抗 N-甲基-d-天冬氨酸受体（抗 NMDAR）脑炎的非典型表现。在抗 NMDAR 脑炎患者中，尽管脑部磁共振成像 (MRI) 的发现并不显着，但小脑性共济失调通常与脱髓鞘疾病、副肿瘤性神经系统综合征的临床特征同时或依次发生。在此，我们报告了一名抗 NMDAR 脑炎患者，其以头晕和步态共济失调为初始症状，同时显示小脑 MRI 高信号，甚至在表现出行为和认知症状之前。我们使用基于细胞和组织的检测排除了其他自身抗体的共存，以建立明确的抗 NMDAR 脑炎的确诊诊断。