Graus et al reported criteria for different types of autoimmune encephalitis. One set of criteria is for anti-NMDA receptor encephalitis. The authors are from multiple institutions from around the world.
Patient selection: encephalitis
Criteria for possible anti-NMDA receptor encephalitis - all of the following:
(1) rapid onset (< 3 months) for >= 4 of the following symptoms:
(1a) abnormal behavior or cognitive dysfunction
(1b) speech dysfunction (pressured speech, verbal reduction, mutism)
(1c) seizures
(1d) movement disorder, dyskinesia, rigidity or abnormal postures
(1e) decreased level of consciousness
(1f) autonomic dysfunction or central hypoventilation
(2) one or both of the following:
(2a) EEG shows focal or diffuse slow or disorganized activity, epileptic activity, or extreme delta brush
(2b) CSF WBC > 5 OR oligoclonal bands
(3) reasonable exclusion of other disorders
If 3 of the symptoms in item 1 are present and if the patient has a teratoma, then the possible diagnosis of possible anti-NMDAR encephalitis can be made.
If 1 or more of the symptoms in item 1 are present and if the patient has IgG anti-GluN1 antibodies and if other disorders can be excluded, then a definitive diagnosis can be made.