N-methyl-D-aspartate receptor antibodies in post–herpes simplex virus encephalitis neurological relapse
Funding agencies: National Institute for Health Research (NIHR) Oxford Biomedical Research Centre, Oxford University Hospitals NHS Trust and the University of Oxford (to Y.H., P.W., and A.V.); NHS Specialized Services for Rare Diseases (neuromyelitis optica; to P.W. and A.V.).
Relevant conflicts of interest/financial disclosures: AV and the University of Oxford, hold patents and receive royalties and payments for antibody assays in neurologic diseases.
Full financial disclosures and author roles may be found in the online version of this article.
ABSTRACT
Herpes simplex virus encephalitis (HSVE) is a devastating condition that relapses, often with a chorea in children, despite adequate antiviral treatment. At relapse, evidence of viral replication is frequently absent, suggesting that the relapse may be immune-mediated. Seven children who had a neurological relapse following their initial encephalitis, identified from 20 cases of pediatric HSVE, were studied. Serum and/or cerebrospinal fluid (CSF) were tested for N-methyl-D-aspartate receptor (NMDAR) and other antibodies previously reported in central nervous system autoimmunity. Five of the 7 relapsing children had choreoathetosis; 2 of these were NMDAR antibody–positive, 2 were negative (1 with HSV-positive CSF), and 1 was not available for testing. An additional patient, who relapsed with cognitive regression but with no movement disorder, was also NMDAR antibody–positive. In 2 of the NMDAR antibody–positive patients who were treated at relapse and in 1 who was treated only after 10 years of having a relapsing encephalopathy, a beneficial response was observed. Neurological relapses after HSVE may frequently be immune-mediated, particularly in children with chorea. NMDAR antibodies are common, and immunotherapy may be beneficial. © 2013 International Parkinson and Movement Disorder Society
