FRIDAY, Sept. 24 (HealthDay News) -- Children with H1N1 influenza, especially if they have an underlying medical or neurologic condition, appear to be at higher risk for neurologic complications such as seizures and encephalopathy than children with seasonal flu, according to research published online Sept. 23 in the Annals of Neurology.
Jeffrey J. Ekstrand, M.D., of the University of Utah School of Medicine in Salt Lake City, and colleagues conducted a retrospective records review of H1N1-related neurologic complications in hospitalized children under age 19 as compared to neurologic complications in hospitalized children associated with seasonal flu from 2004 through 2008.
The researchers found that, of 303 children hospitalized with H1N1, 18 had neurologic symptoms (as opposed to 16 of 234 hospitalized with seasonal influenza); 83 percent of the children with H1N1 infections had underlying medical conditions, primarily neurologic in nature. These children most commonly had H1N1 associated seizures or encephalopathy, and those who suffered seizures tended to present emergently in status epilepticus and to have abnormal electroencephalographs (EEGs) and focal deficits; neurologic complications trended toward being more severe during the second wave of H1N1 than during the first wave. Children in the seasonal flu group had fewer underlying conditions, and were significantly less likely to have encephalopathy, focal neurological findings, or an abnormal EEG.
"This study demonstrates the heightened neurological complications with pandemic 2009 H1N1 influenza in children," the authors write. "In addition, our observation of possible increased severity of neurological complications during the second pandemic wave should lead to close monitoring of potential neurological morbidities in future pandemic H1N1 influenza."