Abstract:Objective To explore the clinical features, treatment and prognosis of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Methods The clinical data of 12 patients with anti NMDAR encephalitis treated in Beijing Chaoyang Integrative Medicine Emergency Medical Center from December 2018 to June 2020 were collected and analyzed retrospectively, including the general data, cerebrospinal fluid (CSF) detection, anti-NMDAR antibody detection, imaging findings,electroencephalographic (EEG)manifestations and treatment prognosis. Results There were 3 males and 9 females, aged 15-59(33.14±5.47） years old.Most of patients were at acute or subacute onset with clinical manifestations of precursor infection symptoms in 4 cases, mental behavior abnormalities in 12 cases, cognitive impairment in 9 cases, epileptic seizure in 6 cases, consciousness impairment in 4 cases,speech impairment in 3 cases and autonomic nerve dysfunction in 3 cases. CSF detection showed 8 cases with elevated pressure, 10 cases with elevated leukocyte number and 8 cases with elevated protein. The detection of anti NMDAR antibody showed 12 cases were positive for anti-NMDAR antibody in cerebrospinal fluid, and 4 cases were positive for anti-NMDAR antibody in serum. Head magnetic resonance imaging (MRI) enhanced scanning showed abnormalities in 8 cases, including 6 cases of medial temporal lobe, 4 cases of insular lobe and 3 cases of frontal lobe (some patients had multiple abnormal sites). CT examination of the chest and the whole abdomen suggested ovarian teratoma in one case. EEG showed 5 cases of mild abnormality, 2 cases of moderate abnormality and 1 case of severe abnormality, mainly manifested as focal or diffuse slow-wave rhythm.After treated with glucocorticoid, immunoglobulin and other immunotherapy, one case was transferred to another hospital for teratoma resection. There were 7 cases with complete recovery, 1 case with recurrence and 4 cases with residual epileptic activity. Conclusions The clinical manifestations of anti-NMDAR encephalitis are variable. For patients with unexplained mental and behavioral abnormalities, cognitive impairment, epileptic seizures, etc., detection of anti-NMDAR antibody in CSF should be performed as soon as possible to initiate immunotherapy early after diagnosis. Meanwhile, the potential tumors could be identified.