Anti-N-methyl-d-aspartate-receptor-encephalitis

In 2007, Dalmau et al described Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Since then, more than 500 patients have been reported, who initially showed psychiatric problems as leading symptoms.

We report the case of a 12-year-old boy with headache and fever. A viral infection with additional psychiatric symptoms was diagnosed and psychiatric examination was initiated. Suspecting a severe emotional disturbance with somatic symptoms, a psychiatric hospital treatment was recommended. The patient developed an impaired consciousness and catatonia. On admission in a neuropediatric clinic, he showed slowed behavior, could not walk, and had continuous perioral hyperkinesia.

The electroencephalography showed slowed background activity. Repeated cerebral magnetic resonance images were normal. Cerebrospinal fluid (CSF) examination showed pleocytosis (37 leukocytes/µL), a normal albumin ratio, intrathecal immunoglobulin synthesis (30% IgG, 45% IgA, 90% IgM), and positive oligoclonal antibodies. The serological findings showed no signs of viral or bacterial infection. Because of further neurological deterioration, therapy with a methylprednisolone pulse twice and intravenous immunoglobulin was started without any clinical effect.

After receiving the positive results for NMDAR autoantibodies in serum (titer 1:15) and CSF (titer 1:32), we initiated a treatment with cyclophosphamide (one time) and rituximab (four times, once a week) as recommended in Anti-NMDAR encephalitis. During this therapy, the patient showed continuous clinical improvement and started to speak and walk again within 4 weeks. After 5 months of rehabilitative treatment, he acted nearly normally again.

In patients with sudden onset of psychiatric symptoms of unknown origin, anti-NMDAR encephalitis always should be taken into consideration and a specific diagnostic and therapeutic work up should be initiated.