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Autoimmune diseases Guide CIDPUSA.ORG

Anti-NMDAR Encephalitis?

As a patient's symptoms progress they will usually be evaluated with blood tests, imaging tests (usually an MRI), and tests of the cerebral spinal fluid. The definitive diagnosis is made by identifying anti-NMDAR antibodies in blood and/or cerebral spinal fluid. Because of the association with a teratoma or other tumors, patients diagnosed with this condition will usually have an evaluation to look for a tumor.

Treatment for anti-NMDAR encephalitis is centered on controlling the body's immune reaction, so first line treatment includes steroids and other anti-immune treatments such as IVIG or plasmapharesis. Patients who do not respond to these treatments may be treated with other immunotherapy medications.

Response seems to be better if treatment is started early. Overall about 60 to 80 percent of patients improve with treatment and have minor or no residual symptoms, about 10 to 25 percent have severe residual deficits and about 5 to 25 percent die; the variability in these numbers reflects the small size of the studies of this disease due to the relative uncommonness of this condition. As many as 10 to 20 percent of patients will have a recurrence of symptoms even after successful treatment, although the symptoms of the relapse are usually not as severe as the initial presentation.

Patients with new onset psychiatric conditions should have anti-NMDAR encephalitis considered as a possible cause of their condition, especially if the characteristics of their condition are atypical and if they have any neurological symptoms as well.




NMDAR encephalitis first appeared in medical literature in 2005 when four women were found to have similar presentations that mimicked either an acute psychotic episode, recent drug use, or malingering. They each had a similar combination of psychiatric symptoms, autonomic instability, and seizures. Additionally, they had CSF inflammatory abnormalities and a neurological syndrome that improved after tumor resection, immunotherapy

NMDAR clinical presentation,

In 70% of patients, there is a prodromal period, averaging 5 days but up to 2 weeks, of a viral-like illness with symptoms of headache, fever, malaise, myalgia, upper respiratory symptoms, nausea, and diarrhea.Memory loss, as well as difficulty with sustained attention, may occur. Symptoms of hyper-religiosity and disorganization in both thought process and behavior may occur. They may become agitated or afraid to the point of combativeness.


Methylprednisolone is an IV steroid that can be given at high doses and is often used with IV immunoglobulins (IVIG) as first-line therapy. IVIG are pooled antibodies, given by IV, that result in the body degrading circulating antibodies, including the anti-NMDA receptor antibodies that are disease-causing.



Epidemiological studies suggest that anti-NMDA receptor encephalitis may be the most common cause of autoimmune encephalitis after acute demyelinating encephalitis..

MRI Brain Scan

 Brain magnetic resonance imaging scans have been reported as normal in 70% of cases



Delay to treatment with immunosuppressive therapy probably results in worsened outcomes, with evidence for permanent hippocampal damage.

USE-Corticosteroids & Intravenous immunoglobulin (IVIG) - to reduce the level of synthesis of endogenous anti-NMDAR antibodies and arrest further neuronal damage Plasmapheresis or plasma exchange - to reduce the antibody titer Tumor removal should be done whenever a tumor is identified, and surgery is feasible. It may also be attempted in scan-negative cases with refractory symptoms, as occult teratomas have been found to be present following the histologic examination of such an ovary, with improvement of clinical features after the surgery. 



Second Line Treatment

Rituximab Cyclophosphamide.

Effects of Rx

Of the 47% who failed to improve with first-line treatment, 57% were put on second-line immunotherapy and showed improvement


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