GFAP, glial fibrillary acidic protein, is an intermediate filament essential for astrocytes cytoskeleton architecture, adhesion, and maintenance of blood–brain barrier. GFAP is involved in the pathophysiology of several neurologic disorders. Here we describe a clinical case in which CSF autoantibodies to GFAP incited an inflammatory meningoencephalomyelitis, termed autoimmune GFAP astrocytopathy. 

Physician assessment, data and neuroimaging analysis for a patient admitted to a Pittsburgh, PA tertiary care referral center in March 2020.

23 y.o. male presented to tertiary care center as transfer from an outside hospital (OSH) with abnormal MRI findings. Symptom onset began with chills and myalgias, initially thought to be viral illness, which progressed to headache and altered mentation. Patient was taken to OSH where he was intubated for agitation and inability to protect airway. Upon transfer, LP showed 112 WBCs, Protein 377, glucose 35, 2 RBCs. He was started on broad spectrum meningitis coverage. MRI showed extensive diffusion restriction T2 prolongation corpus callosum which progressed then resolved on subsequent MR imaging. CSF autoimmune panel was positive at 1:32 titer for GFAP autoantibodies. He was treated with 3 days of Solumedrol 500 mg bid. He cognitively and psycho-socially improved, as well as benefited from inpatient rehab and was able to return to work as a nurse. CT body for malignancy workup was ordered but patient did not complete it.

This case report discusses a rare presentation of encephalitis secondary to autoimmune GFAP astrocytopathy. Classical findings on MRI for this pathology are linear, radially projecting, periventricular contrast-enhancing lesions, which was not seen in this case. This case illuminates a rare imaging finding of GFAP encephalitis and furthermore, presents an uncommon differential diagnosis for consideration in corpus callosum restricted diffusion lesions.