[Biopsy-proven autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy with characteristic image findings: a case report].

A 53-year-old woman was admitted to the hospital because she developed headache and malaise 3 months prior to her arrival, followed by gait disturbance, abnormal behavior, and hallucinations. On admission, she was stupor and showed left hemispatial neglect, and brain MRI showed extensive FLAIR high-signal lesions with contrast enhancement in the bilateral periventricular white matter, and CSF examination showed pleocytosis and elevated protein. A stereotactic brain biopsy was performed from the right temporal lobe lesion, and pathological findings demonstrated a perivascular inflammatory cell infiltrate. After the administration of intravenous methylprednisolone followed by oral prednisolone, she recovered almost completely within three months and the abnormal MRI findings disappeared. Anti-glial fibrillary acidic protein (GFAP) antibody in the cerebrospinal fluid turned out to be positive, then the diagnosis of autoimmune GFAP astrocytopathy was made. Reports of this disease are still rare, and we report this case because of its slowly progressive course and pathological evaluation by brain biopsy.