Magnetic Resonance Imaging Features of GABA-A Receptor Antibody-Mediated Encephalitis

A 77-year-old man with a history of marginal zone lymphoma at remission presented with convulsive status epilepticus. The patient had no history of seizures. Physical examination revealed no focal neurological deficits. Magnetic resonance imaging (MRI) showed 2 hyperintense lesions on the fluid-attenuated inversion recovery (FLAIR) sequence in the right and left inferior frontal lobes without gadolinium enhancement or diffusion restriction (Figure 1). Cerebrospinal fluid (CSF) examination revealed no pleocytosis, normal protein level, and negative oligoclonal bands. The patient started treatment with 3 antiseizure medications given his intermittent clinical and electrographic seizures. Biopsy of the right inferior frontal lesion showed inflammatory changes consistent with reactive gliosis. The patient was treated with a 5-day course of intravenous methylprednisolone with subsequent seizure control.