Neurologic Complications of 2009 Influenza-A H1N1 Infection in Children

Little is known about the neurologic complications of the 2009 Influenza-A H1N1 epidemic in children. We present a retrospective analysis of children evaluated at a tertiary children's hospital who tested positive for H1N1 with neurologic complications. A total of 164 children tested positive for H1N1. Thirty-one of these patients (19%) were evaluated and discharged from the emergency department. Thirty-nine (24%) were treated in the intensive care unit, the remaining 94 (57%) were treated in medical in-patient units. Six subjects died (3.7%). Neurologic complications identified included headache, encephalitis, polyneuropathy, seizures, and malignant hyperthermia. The rate of neurologic complications in this cohort of patients who tested positive for H1N1 was 19%. The incidence of serious neurologic complications was 3%, with another 3% of patients who experienced rapid clinical deterioration and subsequently died. Our observation of neurologic complications associated with 2009 influenza-A H1N1 epidemic suggests the need for clinical vigilance during future influenza epidemics.