RESUMO
Objective To summarize and analysis the clinical features, diagnosis and treatment of the cases which were positive for anti-N-methyl-D-aspartic acid (NMDA) receptor antibodies by indirect immunofluorescence assay (IFA). Methods We analyzed the disease process, clinical characteristics, auxiliary examination , diagnosis, treat-ment, and prognosis of five cases positive for anti NMDA receptor antibodies in their serum and cerebrospinal fluid (CSF). Results Four of the five cases positive for anti-N-methyl-D-aspartic acid (NMDA) receptor antibodies were di-agnosed with anti-NMDA receptor encephalitis and one was diagnosed with Herpes Simplex Virus Encephalitis(HSE). The five cases had a similar disease presentation including prodromal flu-like symptoms in three cases and psychiatric symptoms at onset in three cases. Four cases developed epilepsy and respiratory failure during the disease course and received treatment in the NICU. Four cases had movement disorders during the late stage of isease..Electroencephalo-graphs and brain MRI showed abnormalities in most cases. The virus infection and dysimmunity test were positive in four cases. Patients with the anti-NMDA receptor encephalitis could have a good immediate prognosis after treatment with hormone and immune globulin. However, two cases developed cancer and one case died during one year fol-low-up. Conclusion Patients with HSE may also test positive for anti-NMDA receptor antibodies. Thus, diagnosis of anti-NMDA receptor encephalitis requires a thorough evaluation including patient’s history and disease course to avoid misdiagnosis.