Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable autoimmune disease of the CNS with prominent neuropsychiatric features that primarily affects young adults and children.

To present the diagnosis course of a case of anti-NMDAR encephalitis in a patient with previous diagnosis of Schizophrenia.

Analysis of the patient's clinical records and of a PubMed database review, using “anti-NMDAR encephalitis” as keywords.

We report a single case of a 33-year-old man diagnosed with Paranoid Schizophrenia in 2009 that after 1 year of treatment abandoned follow-up. Six years later, the patient presented to the psychiatric emergency department with persistent headaches, abnormal behavior and loss of motor skill. He was admitted to the psychiatric ward with a presumptive diagnosis of “Catatonic Schizophrenia” and began to manifest fluctuating catatonic symptoms (captured in video). Neuroleptics and benzodiazepines were tried without success. There was a clinical deterioration with autonomic dysfunction, breathing instability and seizures. Complementary exams revealed: EEG with slow base activity; brain MRI with right temporal pole and right frontobasal lesions compatible with head trauma; CSF with pleocytosis; and positive anti-NMDAR antibodies. Occult neoplasm was excluded. Treatment with high-dose steroids, intravenous immunoglobulins, followed by cyclophosphamide resulted in relevant clinical improvement.

As early detection of antibodies may allow for earlier treatment of anti-NMDAR encephalitis, which is associated with better outcomes, we believe the present case underscores the importance of clinicians maintaining vigilance for neuropsychiatric symptoms that have not adequately responded to therapy.

The authors have not supplied their declaration of competing interest.