Analysis of three cases of anti-N-methyl-D-aspartate receptor encephalitis without tumor

Abstract

Objective To investigate the clinical syndrome，investigations，therapeutic intervention and prognosis of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis without tumor. Methods Compared with 3 patients with ovarian teratoma，3 patients with anti-NMDAR antibodies in cerebrospinal fluid and serum，without evidence of tumor，were retrospectively reviewed. Results All of the patients with anti-NMDAR encephalitis developed a multistage illness that progressed from psychosis，memory deficits，seizures and language disintegration into a state of unresponsiveness with catatonic features associated with abnormal movements，and autonomic instability.Brain magnetic resonance imaging was unremarkable.Fluorodeoxyglucose positron emission tomography showed variable multifocal cortical and subcortical abnormalities that changed during the course of the disease.Electroencephalograms were abnormal in all patients，which showed diffuse slow waves，and one showed extreme delta brush.Cerebrospinal fluid showed mild to moderate lymphocytic pleocytosis.Patients without tumor responded slower to treatment with first line immunotherapy especially in the patient with delayed diagnosis than patients treated with tumor resection who received similar initial immunotherapy，and one patient recovered dramatically following the treatment with second-line immunotherapy. Conclusions The disease course of anti-NMDAR encephalitis without tumor is typically prolonged than the patients with tumor.Early administration of second-line immunotherapy is important when first line immunotherapy fails. Key words: Encephalitis; Receptors，N-methyl-D-aspartate; Immunotherapy; Prognosis