Objective: To improve the understanding of the gamma-aminobutyric acid-B receptor (GABA_BR) limbic encephalitis in clinical practice.

Methods: This paper reports the diagnosis and treatment of a patient with anti-GABA_BR antibody-positive limbic encephalitis misdiagnosed as ischemic stroke at the first diagnosis, focusing on the clinical manifestations, imaging findings and differential diagnosis of anti- GABA_BR antibody-positive limbic encephalitis.

Results: A patient who was diagnosed as anti-GABA_BR antibody-positive limbic encephalitis presented with ischemic stroke as the first manifestation, followed by progressive cognitive impairment and seizures. The anti-GABA_BR antibodies were proved in the cerebrospinal fluid. Imaging findings revealed abnormal signals in left hippocampus, with FDG metabolism was elevated and no evidence of tumor was found. The patient improved significantly after administration of gamma globulin.

Conclusion: Anti-GABA_BR encephalitis is an uncommon autoimmune disease, which has been known to be often associated with cancer, and its pathogenesis is related to the autoimmune antibody attack on GABA_BR. Patients usually have acute or subacute onset, with a history of precursor infection, and the significant clinical manifestations are seizures and cognitive impairment. The diagnosis depends on a detailed history, physical examination and auxiliary examination. MR can find abnormal signals in the hippocampus and temporal lobe. The anti-GABA_BR antibodies proved in the cerebrospinal fluid can confirm the diagnosis. Early diagnosis and immunosuppressive treatment will improve the patient’s condition.