Analysis Of Clinical Characteristics Of 12 Patients With Anti Gamma-aminobutyric Acid-B Receptor(GABAB) Encephalitis

Objective: To study the clinical characteristics of anti gamma-aminobutyric acid-B(GABAB)receptor encephalitis and to explore the factors affecting the prognosis of antiGABAB receptor encephalitis.Methods: The clinical data of patients who were diagnosed with anti-GABAB receptor encephalitis in the Department of Neurology,the First Hospital of China Medical University from January 2015 to January 2020 were collected,including general scharacteristics,clinical symptoms,auxiliary examination results,treatments and prognosis,and descriptive analysis were performed.According to the modified Rankin Scale(m RS)score,patients were divided into good prognosis group(m RS score <2 points)and poor prognosis group(m RS ? 2 points).The clinical characteristics and immunotherapy methods in the two groups with different prognosis were compared.Results: Among the 12 selected patients,7 were female and 5 were male,with a median age of 65.5 years.Prodromal symptoms were found in 33%(4 cases)of the all patients.Epilepsy,mental symptoms,occurred in all patients.11 patients had cognitive impairment.In addition,there were some rare symptoms such as limb dysfunction(2 cases),inadequate lung ventilation(2 cases),headache(2 cases),blurred vision(1 case),and general pain(1 case).All 12 patients were positive for GABAB receptor antibody in cerebrospinal fluid,and no positive for combined antibody.Among 37.5%(3 cases)patients abnormal signals were observed individually in hippocampus(3 cases),temporal lobe(1 case)and insular lobe(1 case).63%(5 cases)patients had abnormal changes in electroencephalogram(EEG)at the onset of the disease.Lung cancer were found in 3 cases,two of which were more likely to be malignant.At the time of discharge,8 patients had a good prognosis,3 patients had a poor prognosis and 1 patient gave up treatment.There was no significant difference between the general characteristics,prodromal infection,first symptoms,auxiliary examination results,and immunotherapy methods in the patients with good prognosis and in those with poor prognosis.Conclusion: Anti-GABAB receptor encephalitis should be considered in those elderly encephalitis patients which with epilepsy as the first symptom,combined with mental symptoms and cognitive impairment.At the onset of the disease,the head magnetic resonance imaging(MRI)and EEG could be normal.The patients can be diagnosed when the antibody of GABAB receptor in CSF was confirmed,and they should be screened for tumors.Patients with anti-GABAB receptor encephalitis respond well to immunotherapy.In this study,no significant differences were found between the clinical characteristics,and different immunotherapy methods in the patients with good prognosis and in those with poor prognosis.