Area postrema syndrome with linear enhancement along the surface of the brainstem and fourth ventricle in autoimmune GFAP astrocytopathy

BACKGROUND: Glial fibrillary acidic protein (GFAP) astrocytopathy, a novel autoimmune disease of the nervous system, was first defined in 2016. To our knowledge, area postrema syndrome (APS) with linear enhancement along the surface of the brainstem and fourth ventricle is extremely rare in this disorder. CASE PRESENTATION: A Chinese woman presented with intractable nausea and vomiting after onset of flu-like symptoms. Brain magnetic resonance imaging (MRI) disclosed abnormal signal intensities in the dorsal medulla oblongata including area postrema. Besides, linear enhancement surrounding the surface of the brainstem and fourth ventricle was visualized after gadolinium injection. Cerebrospinal fluid (CSF) analysis showed increased cell count and protein. A cell-based assay was positive for anti-GFAP IgG in CSF. She was diagnosed with autoimmune GFAP astrocytopathy and treated with high-dose glucocorticoid. The patient received a quick recovery with entire resolution of the initial abnormalities. CONCLUSIONS: Isolated APS can be the initial manifestation of autoimmune GFAP astrocytopathy. Linear enhancement surrounding the surface of the brainstem and fourth ventricle is another neuroradiological hallmark.