Heightened neurologic complications in children with pandemic H1N1 influenza

Abstract

The 2009 pandemic influenza A (H1N1) has been recognized to cause neurological complications including seizures and encephalopathy. We identified 18 children with 2009 H1N1 influenza and neurological complications from first and second wave activity, and compared characteristics to seasonal influenza. Seizures, encephalopathy, and status epilepticus were common presentations. Focal neurological symptoms persisted in 22% of patients at discharge. Compared to seasonal influenza, patients with pandemic 2009 influenza were more likely to have encephalopathy, focal neurological findings, aphasia, and abnormal electroencephalographic findings. In addition, we noted a trend toward heightened neurological complications following second wave influenza activity. ANN NEUROL 2010

Neurologic complications of influenza A(H1N1)pdm09

“…However, the authors stated that compared to seasonal influenza, patients with pandemic 2009 influenza were more likely to have encephalopathy, focal neurologic findings, aphasia, and abnormal electroencephalographic findings. 15 Another study from Australia in 2007 (of influenza hospitalization in one of our surveillance hospitals) found 1.6% (2 of 122) of hospitalized children with laboratory-confirmed seasonal influenza had encephalitis. 33 Our findings, from influenza surveillance and literature review, suggest that the proportion of neurologic complications associated with the 2009 pandemic influenza admissions is comparable to that from published studies of seasonal influenza complications.…”

“…We were able to calculate the proportion of neurologic complications in children hospitalized with laboratory-confirmed pandemic influenza in 2009 from 3 studies, 2 in the United States (5.9% and 7.5%) and 1 in the United Kingdom (6.0%). 15,19,29 The proportion of encephalopathy in children hospitalized with laboratory-confirmed pandemic influenza was 1.7% in another study. 12 The presenting symptoms, neurologic complications, CSF and neuroimaging findings, treatment, and outcome of the 87 children are summarized in table e-2.…”

Neurologic Complications and Outcomes of Pandemic (H1N1) 2009 in Korean Children

“…However, further evaluation and longterm follow-up is required to confirm this relationship. Compared with seasonal influenza, H1N1 is not more severe, but neurologic complications such as encephalopathy, focal neurologic sign, aphasia and abnormal electroencephalogram findings can be more common (11,20). Neurologic complications resulting from H1N1 in pediatric populations include various clinical manifestations such as seizure, aseptic meningitis, encephalitis and acute disseminated encephalomyelitis and can result in significant acute and residual neurologic sequelae (14,18).…”

H1N1-Related Encephalitis in the Postpandemic Era

“…H1N1 often presents with a febrile disease with mild respiratory symptoms and rarely causes severe cardiac, pulmonary and neurologic complications (2). H1N1 causes neurologic complications such as encephalopathy, encephalitis, seizures, ischemic stroke, benign intracranial hypertension, myelitis, Reye syndrome, and Guillain-Barre syndrome, more than seasonal influenza (3,4).…”