Abnormal level of consciousness predicts outcomes of patients with anti-NMDA encephalitis

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is an acute form of encephalitis with an autoimmune etiology. We aimed to study clinical characteristics and treatment outcomes and assess the predictive factors associated with patient outcome. In this retrospective study, patients who presented with cardinal symptoms of anti-NMDA encephalitis and positive anti-NMDA receptor antibody results in their cerebrospinal fluid were included in the study. Thirty-one patients were identified. The median age of onset was 19 years (IQR 15.0-31.0). Females were predominant (61.8%). The main clinical symptoms were neuropsychiatric symptoms (87.1%) followed by abnormal movement (71%), seizures (51.1%), and autonomic instability (41.9%). Eleven patients (35.5%) exhibited decreased levels of consciousness. Abnormal MRI results were found in only 35.5% of the patients. CSF abnormalities usually involved mild pleocytosis. Only 67.7% of serum samples were positive against the anti-NMDAR antibody, whereas 100% of CSF samples were positive. Tumor-related information was only available for 20 patients. Only one case involved an ovarian teratoma. All patients received first-line therapy (intravenous pulse methylprednisolone and plasmapheresis). Three patients were treated with second-line therapy (IV cyclophosphamide). Twenty patients (64.5%) had favorable outcomes in our cohort (mRS 0-2) after a 1-year follow-up. An abnormal level of consciousness was a factor associated with a nonfavorable outcome (OR 15.65, 95% CI 2.30-106.29, p value <0.01).