Background Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an inflammatory central nervous system (CNS) disorder that usually presents as steroid responsive encephalitis, meningitis, myelitis, or meningoencephalomyelitis. Hypertrophic pachymeningitis (HP) is an uncommon disorder that causes a localized or diffuse thickening of the dura mater. Depending on the etiology, HP can be idiopathic or secondary to a wide variety of other diseases. There are no reports of autoimmune GFAP astrocytopathy presenting as HP.

Methods In this case report, we describe a rare case of pediatric HP possibly associated with anti-GFAP antibody.

Results A 13-year-old previously healthy girl presented with headache for nearly 8 months with left-sided peripheral facial palsy and left-sided abductor nerve palsy in the second month of course. Magnetic resonance imaging (MRI) of the brain revealed contrast enhancement of hypertrophic dura mater. Anti-GFAPα antibodies were positive in serum and cerebrospinal fluid. The patient improved clinically after steroid treatment with partial resolution of abnormal intracranial MRI lesions.

Conclusion The present study suggests that HP may be one of the clinical phenotypes for autoimmune GFAP astrocytopathy or GFAP antibody is a biomarker for HP.

背景 自身免疫性胶质纤维酸性蛋白 (GFAP) 星形细胞病是一种炎症性中枢神经系统 (CNS) 疾病，通常表现为类固醇反应性脑炎、脑膜炎、脊髓炎或脑膜脑脊髓炎。肥厚性硬脑膜炎 (HP) 是一种罕见的疾病，会导致硬脑膜局部或弥漫性增厚。根据病因，HP 可能是特发性的或继发于多种其他疾病。没有关于表现为 HP 的自身免疫性 GFAP 星形细胞病的报道。

方法 在本病例报告中，我们描述了一个可能与抗 GFAP 抗体相关的罕见的小儿 HP 病例。

结果 13岁女性，既往健康，头痛近8个月，病程第2个月出现左侧周围性面神经麻痹和左侧外展神经麻痹。大脑的磁共振成像 (MRI) 显示肥厚硬脑膜的对比增强。血清和脑脊液中抗 GFAPα 抗体阳性。类固醇治疗后，患者的临床症状有所改善，颅内 MRI 异常病变部分消退。

结论 本研究提示 HP 可能是自身免疫性 GFAP 星形细胞病的临床表型之一或 GFAP 抗体是 HP 的生物标志物。