Extreme delta brush and distinctive imaging in a pediatric patient with autoimmune GFAP astrocytopathy.

Autoimmune encephalitis has been increasingly recognized within the pediatric population, and the number of implicated autoantibodies continues to grow. The identification of characteristic clinical and paraclinical features helps direct the evaluation and increases the likelihood of making a definitive diagnosis of a specific antibody-mediated encephalitis. The finding of extreme delta brush on electroencephalogram (EEG) has been suggested to serve as a clinical clue to the diagnosis of anti-NMDA-R encephalitis. Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a recently described antibody-mediated meningoencephalomyelitis, reported almost exclusively in adult patients. We report a case of autoimmune GFAP astrocytopathy in a pediatric patient with extreme delta brush pattern on EEG, negative anti-NMDA-R antibodies, and distinctive MRI findings. The findings reported herein should prompt clinicians to consider the diagnosis of autoimmune GFAP astrocytopathy in patients with suspected autoimmune encephalitis.