Approximately 32% of children with febrile status epilepticus (FSE) had a human herpesvirus (HHS)-6B infection, according to research published in the June 14 online Epilepsia.
About 7% of children with FSE had an HHV-7 infection. Researchers found no differences in the rates of electroencephalography abnormalities or MRI abnormalities between children with FSE with and without HHV-6B or HHV-7 infection.
As part of a study of the consequences of prolonged febrile seizures in childhood, Leon G. Epstein, MD, Professor in the Ken and Ruth Davee Department of Neurology at Northwestern University Feinberg School of Medicine in Chicago, and colleagues assessed the frequency of primary and reactivated HHV-6A, HHV-6B, and HHV-7 infection as a cause of FSE. The goal was to test the hypothesis that FSE resulting from HHV-6A, HHV-6B, or HHV-7 infection is more likely to cause hippocampal injury and temporal lobe epilepsy.
The investigators evaluated data for 169 patients (88 male) with FSE whose mean age was 15.8 months. Infections were diagnosed through real-time quantitative fluorescent probe DNA and RNA polymerase chain reaction. None of the patients had HHV-6A infection.
“In the 38 subjects with primary HHV-6B infection, we conclude that this is the likely cause of FSE,” stated Dr. Epstein’s group.
“The demonstration of primary infection with either of these viruses at the time of presentation with FSE strongly suggests that the virus is the proximate cause of the fever, which in turn is associated with FSE. However, we cannot distinguish whether the FSE is, at least in part, due to a direct effect of the virus on the brain or secondary to the inflammatory process and high fever caused by the viral infection. The current data … [lay] the foundation to determine whether these subjects are more likely to develop hippocampal injury and [temporal lobe epilepsy],” he concluded.
Epstein LG, Shinnar S, Hesdorffer DC, et al. Human herpesvirus 6 and 7 in febrile status epilepticus: The FEBSTAT study. Epilepsia. 2012 Jun 14; [Epub ahead of print].