Autoimmune limbic encephalitis as an emerging pediatric condition: case report and review of the literature.

Limbic encephalitis, first described in the 1960s as a paraneoplastic condition, has emerged as an autoimmune condition, occurring often without evidence of an underlying tumor. Many novel autoantibodies have been identified, and this diagnosis is increasingly being made in the pediatric population. This article reports the case of a 16-year-old boy who presented following gastrointestinal illness with subacute evolution of neuropsychiatric symptoms. Brain magnetic resonance imaging revealed progressive hippocampal signal abnormality and swelling. N-methyl-D-aspartate (NMDA) receptor antibody was detected in serum. The patient responded well to pharmacological immunotherapy but has residual cognitive deficits. The available literature on this condition is reviewed. Limbic encephalitis should be considered in the differential diagnosis in children presenting with encephalopathy, particularly with neuropsychiatric manifestations. Long-term surveillance and close follow-up are required to accurately clarify tumor risk and natural history of this condition in children and balance these factors with risks of radiation exposure through imaging.