A major research is on to devise ways and means of protecting the survivors of traumatic brain injuries from epilepsy.
For it has been estimated thousands of such survivors do develop epilepsy months or years later.
The risk is especially high for certain kinds of war injuries. Studies of Vietnam veterans suggest up to 50 percent, says Dr. Nancy Temkin of the University of Washington.
Epilepsy may not begin with the classic jerking seizures, but instead with memory loss, attention problems and the like. Doctors could mistakenly attribute such subtle symptoms to the original brain injury, post-traumatic stress or some other factor. So epilepsy becomes inevitable.
Now researchers are trying to figure out whether the newer seizure-treating drugs like Topamax or Keppra might actually prevent epilepsy if they're taken immediately after a serious brain injury.
Almost 3 million Americans have epilepsy, a condition in which the brain essentially suffers periodic electrical storms. When its circuits misfire fast enough, a seizure results.
Epilepsy has multiple causes. Some people are born with it.
But about 5 percent of the nation's epilepsy was caused by traumatic brain injury, or TBI. What's the risk? Roughly 25 percent of survivors of moderate to severe brain injury will develop epilepsy. Even more, perhaps, for certain types of war injuries.
Injuries that cause bleeding inside the brain are the riskiest.
The population at risk is huge: Some 1.4 million children and adults suffer serious brain injuries every year from car or bike crashes, falls, gunshot wounds and other trauma.
As the damaged brain tries to rewire itself -- a crucial process called plasticity -- misfiring circuitry can form. Injured neurons can make new connections in wrong places, or overly excitable connections. Even the brain's genes change the way they work after head injury.
"You need the plasticity for recovery. You don't want to stop it. You just want to structure it in a way that it aids recovery without causing seizures," Dr.Temkin explains.
It's not clear yet how to do that, so scientists instead are testing what's available -- seizure-controlling drugs -- as possible epilepsy preventers. Three old medications have failed.
New pilot studies are checking on Topamax and Keppra. Initial indications are that they could be effective, it is said.