Roots of Child Epilepsy are Clearer

Childhood viral infection and epilepsy may be connected

(RxWiki News) It is difficult and scary when your child is experiencing seizures. It is reassuring to know that researchers are working hard to find the causes and treatments.

A ten year study recently strengthened the link between a certain type of epilepsy and a strain of the herpes virus.

The study showed infants with prolonged seizures and fever suffer from roseola virus infection, a virus that leads to a condition that can progress into epilepsy.

The study, funded by National Institutes of Health (NIH) and led by Leon Epstein, MD, a pediatric neurologist at the Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago, examined the frequency of the HHV-6 and HHV-7 strain of herpesvirus in children experiencing seizures between the ages of 1 month to 5 years.

"Consult with your doctor regarding rashes or fevers."

Investigators found 169 children out of 199 children experiencing seizures had either HHV-6 or HHV-7. Thirty-two percent of the 169 children had HHV-6B, a specific form of HHV-6. Of the 169 children, 7.1 percent had HHV-7. Most patients with HHV-7 also had HHV-6B.

Patients were recruited within 72 hours of an episode. During initial hospitalization, researchers conducted a detailed survey to gather information about the seizure, prior development, family history and prior illnesses. A physical and neurological examination was conducted. Blood specimens and cerebrospinal fluid were collected. The blood was inspected for the presence of HHV-6 and HHV-7.

HHV-6B and HHV-7 are the two herpesvirus strains that cause the roseola virus infection. The roseola virus infection is spread from person to person, most likely by transfer of saliva. It is most common in children 6 to 24 months of age, with an average onset at 9 months of age.

Nearly everyone has been infected by HHV-6B or HHV-7 by adulthood. It is the cause of the common childhood rash and can cause limbic encephalitis.

Limbic encephalitis is a condition that causes swelling of the brain and frequently progresses to epilepsy. Half of all transplant patients with limbic encephalitis caused by HHV-6B develop epilepsy within 3-5 years.

In addition, large amounts of HHV-6B DNA have been found in the brain tissue of patients with certain forms of epilepsy that do not respond to drug treatment.

It is suspected that the viruses linger in the body and surface as epilepsy in response to unknown triggers.

Current treatment for infants experiencing seizures is antiseizure medication. Researchers of the study expect that further research may suggest that these infants would benefit more from anti-inflammatory treatment or antiviral treatment. Although transplant patients with HHV-6B related seizures are routinely treated with antivirals, researchers remain cautious about the use of current oral antiviral drug therapy, as it can lead to anemia.

“We think that it is time that someone proposes a clinical trial of the antiviral valganciclover,” says Kristin Loomis, executive director of the non-profit HHV-6 Foundation. “We don’t understand why parents of these infants aren’t in an uproar, demanding more research and clinical trials.”

Future research includes the investigation of any cognitive problems that appear due to the roseola virus.

The study was published in the journal Epilepsia and supported by National Institute of Neurological Disorders and Stroke (NINDS) grants. NINDS is a part of the NIH that conducts and funds research on brain and nervous system disorders. The NIH is an agency of the United States Department of Health and Human Services and is responsible for biomedical and health-related research.

The study’s authors have reported no conflicts of interest.

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Review Date: 
June 27, 2012