Anti-N-Methyl-D-Aspartate Receptor (anti-NMDAR) autoimmune encephalitis may go undiagnosed for some time. Patients often present first to a psychiatrist. A high index of suspicion is needed to make the diagnosis.

Psychiatric presentations may include:

(1) delirium and/or disorientation

(2) schizophrenia or other psychosis

(3) catatonia

(4) mania

(5) anxiety and/or agitation

(6) depression or bipolar disease


Additional findings include:

(1) A patient placed on a neuroleptic may present with neuroleptic malignant syndrome.

(2) extrapyramidal symptoms with only low doses of haloperidol (Bergink et al)


Diagnostic features include:

(1) variable neurologic symptoms (seizures, dyskinesia, cognitive impairment)

(2) presence of anti-NMDAR antibodies in the CSF

(3) exclusion of other diagnoses

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