Teaching NeuroImages: Linear Radial Periventricular Enhancement in Glial Fibrillary Acidic Protein Astrocytopathy

A 48-year-old woman presented with asymptomatic painless optic disc swelling, seizures, cognitive decline, and weakness over 3 months. She had an upper motor neuron pattern of grade 4/5 weakness in all 4 limbs. Brain MRI revealed striking linear radial perivascular enhancement in the deep white matter1,2 (figure, A and B); MRI spine revealed longitudinally extensive C3-to-conus cord T2 hyperintensity and T1 enhancement2 (figure, C and D). CSF demonstrated glial fibrillary acidic protein (GFAP) pattern by indirect immunofluorescence with GFAPα specificity confirmed by cell-based assay. The patient improved clinically (figure, E and F) with steroid treatment. Linear/radial perivascular enhancement in the deep white matter prompts consideration of a corticosteroid-responsive meningoencephalomyelitis termed autoimmune GFAP astrocytopathy.1