A Mild Case of Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy With Chronic Onset

A 25-year-old woman presented with mild fever and fatigue that began four months prior to admission. At 30 days after onset, she developed bilateral visual field impairment with hand tremors. Gait difficulty occurred at 60 days after onset. On admission, the patient was alert and well-oriented. Examination revealed central scotomas, papilledema in both eyes, postural tremors in both hands, hyperreflexia in the limbs, positive pathological reflexes in the lower extremities, and spastic gait. Cerebrospinal fluid analysis showed an elevated cell count and protein levels as well as positive glial fibrillary acidic protein (GFAP) α antibodies. Brain magnetic resonance imaging (MRI) revealed hyperintensities in the bilateral cerebral hemispheres and dorsal brainstem on T2-weighted images. These lesions did not show enhancement with gadolinium. Methylprednisolone pulse therapy followed by oral prednisolone led to almost complete resolution of neurological symptoms and MRI abnormalities. Although GFAP astrocytopathy typically presents acutely or subacutely with severe symptoms, it should be considered when patients present with a more chronic course and relatively mild symptoms, as seen in this case. GFAP astrocytopathy should also be considered when patients present with gradually expanding white matter lesions.