This elevated body temperature induced seizures in the hippocampus and related brain structures of the rats. So far, the only evidence for this assumption has come from epidemiological studies, finding that 30 to 50 percent of adults suffering from TLE have a history of febrile seizures in early childhood, Baram said. Baram's team for the first time has provided experimental evidence for this assumption. The researchers determined whether the rats that had experienced prolonged febrile seizures were more susceptible to developing epilepsy in adulthood. They found that these rats were much more sensitive to drugs that can induce seizures by exciting the brain, or to electrical stimulation than the rats that had not experienced the febrile seizures as neonates.
Epilepsy means spontaneous seizures.
That is, seizures that do not have an obvious trigger. They provide a first 'hit' that makes the brain more sensitive to a second event. However, if there has already been a previous brain injury, then prolonged febrile seizures on top of that make the likelihood of epilepsy higher. If we find no preexisting brain injury, then the likelihood of epilepsy is very small. Baram now wants to understand the mechanisms by which these prolonged febrile seizures change some of the brain cells so that they become more susceptible to generating seizures in adulthood.