Retrospective Analysis Of NMDAR Antibodies In Patients With Possible Virus Encephalitis

Objective To summarize and analyze the clinical, imaging, electroencephalogram and CSF cytology features of Anti-NMDA-receptor(NMDAR) encephalitis,and to investigate the herpes simplex virus infection in patients with NMDAR encephalitis.Methods CSF of 48 patients diagnosed as possible viral encephalitis in our department in the past 2 years were retrospectively examed for NMDAR antibody by method of fluorescence immunoassay, and the clinical data of patients with positive results of NMDAR antibody were collected and analyzed retrospectively. Fluorescent quantitative PCR technology was used for the detection of HSV I&II genotype in CSF of patients with positive NMDAR-antibody.Results Ten of 48 patients previously diagnosed as possible viral encephalitis were found to be positive in NMDAR antibody detection of CSF,with a male:female ratio of 6:4, aged 17 to 70 years. Eight cases had prodromal symptoms consisting of fever, upper respiratory-tract symptoms and diarrhea. The most common initial symptoms were psychiatric disturbance(4 cases) and epileptic seizure(4 cases), two cases started with headache and disturbance of consciousness.The general clinical features were similar to viral encephalitis, symptoms and signs consisted of fever(8 cases),headache(5 cases), disturbance of consciousness(4 cases), epileptic seizure(6 cases),psychiatric disorder(7 cases), positive meningeal irritation sign(3 cases) and pathological reflex(3 cases), involuntary movements of the limbs(2 cases).Brain MRI of 1 patient showed T2 and FLAIR signal hyperintenstity in the limbic lobe. The majority EEG tests(8 cases)were abnormal.Cerebrospinal fluid cytology showed lymphocyte reaction(5 cases). Nine patients were discharged with obviously improved, only one non-remission patientgived up on treatment. HSV I&II genotype PCR test of ten paitents with NMDAR encephalitis were all negative. Conclusion The clinical manifestations of antiNMDAR encephalitis and viral encephalitis are similar. Anti-NMDAR encephalitis should be suspected in unknown etiology of encephalitis, and NMDAR antibody detection should be performed to confirm the diagnose.