H1N1 Virus Linked to Seizures in Children
Seasonal flu shots this year also cover H1N1 virus, a fact that is important given the results of a new study in which H1N1 was linked to a higher rate of seizures and other neurological complications in children. Details of the H1N1 study are in the September issue of Annals of Neurology.
Not only seizures but also number of conditions associated with H1N1 in children
Researchers at the University of Utah conducted a retrospective study in which they compared neurological complications in children with H1N1 compared to the seasonal flu. Observed neurological complications included seizures, status epilepticus, encephalopathy, encephalitis, aphasia, neuropathy, Guillain-Barre syndrome, and other focal neurological issues.
Records of 303 children hospitalized with 2009 H1N1 between April 1 and November 30, 2009 were compared with those of 234 children hospitalized for seasonal flu from July 1, 2004 to June 30, 2008.
Among the children with H1N1, 18 experienced neurological complications. Eighty-three percent of the children had an underlying medical condition, the most common being seizures (67%) and encephalopathy (50%). More than half of the children who had seizures experienced status epilepticus, a life-threatening condition.
In the comparison group, only 25 percent of patients had an underlying medical condition. Sixteen patients experienced neurological issues, although none had encephalopathy, aphasia, or focal neurological deficits.
Josh Bonkowsky, MD, PhD, and his colleagues found that children with H1N1 were more likely to have neurological deficits and to have abnormal electroencephalogram findings. They also required “ongoing treatment with anti-epileptic medications upon discharge from the hospitals,” noted Bonkowsky.
An earlier study from July 2009 by researchers at University of Texas Southwestern Medical Center in Dallas reported that children with flu-like symptoms and unexplained seizures appeared to have H1N1 flu. Until that time, seizures and other neurologic issues had not been linked to H1N1. An August 2010 study in the Pediatric Infectious Disease Journal reported neurologic signs of H1N1, including seizures, meningoencephalitis, and acute necrotizing encephalopathy.
During the recent H1N1 (swine flu) pandemic, approximately 14 to 28 million children ages 17 years and younger were infected with the virus. Although the World Health Organization (WHO) International Health Regulations Emergency Committee officially declared that the 2009 H1N1 pandemic was over, the virus is still very much alive.
To continue the fight against H1N1, the 2010-2011 flu vaccine, which the Centers for Disease Control and Prevention recommends for everyone older than 6 months of age, will protect against H3N2, an influenza B virus, and H1N1.
This study highlights the possibility of seizures in children who are infected with H1N1. Dr. Bonkowsky also pointed out that “the absence of proven treatments for influenza-related neurological complications underlines the importance of vaccination.”
Centers for Disease Control and Prevention
Ekstrand JJ et al. Annals of Neurology 2010 Sept. 20; DOI:10.1002/ana.22184
Evans A et al. MMWR 2009; 58: 773-78
Rellosa N et al. Pediatric Infectious Disease Journal 2010 Aug 31