Neuropediatrics 2011; 42 - VS08
DOI: 10.1055/s-0031-1273972

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis: discussion of different phenotypes in two pediatric patients

M Brunner-Krainz 1, U Gruber-Sedlmayr 1, K Pfurtscheller 1, E Sorantin 2, T Kröpfl 3, B Plecko 1
  • 1Univ. Klinik f. Kinder- u. Jugendheilkunde, Allg. Pädiatrie, Graz, Austria
  • 2Univ. Klinik f Radiologie, Klinische Abteilung f Kinderradiologie, Graz, Austria
  • 3Klinik für Kinder- und Jugendpsychiatrie, Graz, Austria

Anti-NMDA receptor encephalitis is a severe disorder caused by antibodies against the NR1 subunit of the NMDA-receptor altering glutamatergic neurotransmission. The disease was initially described in young female patients with ovarian teratomas. There are recent case reports of patients without tumors, especially in children. The onset of the disease is subacute, mostly with psychiatric symptoms, later accompanied by a dystonic or choreatic movement disorder, altered consciousness, autonomic instability and epileptic seizures. The Anti-NMDA receptor encephalitis is potentially reversible but response to immunosuppression may be delayed.

Case reports: A 21 months old boy presented with changed behaviour and loss of speech, followed by recurrent generalized seizures and a choreatic movement disorder wich led to respiratory insufficiency. No infectious or inflammatory cause was found and cranial MRI was normal. Anti-NMDAR antibodies in CSF were positive. Immunmodulatory therapy with corticosteroids and IVIG showed no effect. After plasmaphereses mycophenolatmofetil was started. Six months later he was able to walk unsupported, behaviour was still autistic.

The second patient, a 17 year old girl was diagnosed retrospectively. She presented with nonepileptic seizures, altered behaviour and memory disturbance. Over weeks she developed agitation, irritability, a dystonic movement disorder and epileptic seizures. The lumbar puncture revealed pleocytosis without infectious cause. Under antiepileptic and antipsychotic therapy she recovered within 5 months having amnesia for this time. By then the diagnosis was found by NMDA-autoantibodies in CFS obtained during the acute phase.

Conclusion: These two cases illustrate the broadening spectrum of NMDAR autoantibody mediated encephalitis. Therefore NMDAR autoantibodies should be determined in serum or CSF of patients with encephalitis or chorea of unknown origin.

Acknowledgement: Autoantobodies were determined in the Laboratory of Neurosciences Group, University of Oxford, UK.