Clinlab Navigator

NMDA Receptor Autoantibody Encephalitis

Autoantibody-mediated encephalitis is a group of inflammatory brain disorders characterized by neuropsychiatric symptoms and the presence of autoantibodies against neuronal antigens. Autoimmune encephalitis is the third most common cause of encephalitis after viral infections and acute disseminated encephalomyelitis. One of the most clinically distinctive types of autoantibody-mediated encephalitis is anti-NMDA receptor encephalitis.

Anti-NMDA receptor encephalitis typically affects women in their 20s and 30s, and about half of patients have an ovarian teratoma. Only 2% of women have a neoplasm other than ovarian teratoma. These other neoplasms include breast adenocarcinoma, ovarian neuroendocrine tumors, sex cord stromal tumor, pseudopapillary neoplasm of pancreas, neuroblastoma, and Hodgkin lymphoma. a. It can also occur in younger patients and in men, in whom it is less likely to be associated with a neoplasm.Neoplasia has been documented in 5% of men with NMDA receptor antibody; either testicular germ cell tumors or small-cell lung carcinoma.The female to male ratio of patients is about 4:1.

Patients with NMDA-receptor antibody often present with headache, fever, nausea, vomiting, diarrhea, or upper respiratory tract symptoms. Shortly afterwards, they develop psychiatric symptoms including anxiety, insomnia, fear, delusions, mania, and paranoia. Movement disorders include oro-lingual-facial dyskinesias, generalized chorea, oculogyric crisis, dystonia, and rigidity. Autonomic manifestations include hyperthermia, tachycardia, hypersalivation, hypertension, bradycardia, hypotension, urinary incontinence, and erectile dysfunction.

Outcome is usually favorable, but recovery may take a year or longer. Approximately one fourth of patients relapse if they do not receive immunotherapy. Removal of a teratoma may be curative.

This antibody is more commonly detected in CSF than in serum. Serum testing yields false negative results in about 14% of cases.


Dalmau J and Graus F. Antibody-medicated encephalitis, N Engl J Med 2018;378:840-850.



AddThis Social Bookmark Button