Although it has been used for other purposes for decades, a sugar substitute may turn out to be a potential cure for epilepsy.
2-deoxy-glucose, or 2DG, has long been used in radio labeling, medical scanning and cancer imaging studies in humans. But now, researchers at the University of Wisconsin-Madison have discovered that it also blocks the onset of epileptic seizures in laboratory rats.
Reported in the October 2006 issue of Nature Neuroscience, the findings have potentially huge implications for up to half of all epileptic patients who currently have no access to treatment, says senior author Avtar Roopra, a UW-Madison assistant professor of neurology.
"We pumped the rats full [of 2DG] and still saw no side effects," says Roopra, who estimates that the compound may be available for human use within five years. "I see 2DG as an epilepsy management treatment much like insulin is used to treat diabetes."
"All the available epilepsy treatments have focused on suppressing seizures," says co-author and renowned epilepsy expert Tom Sutula, a UW-Madison professor of neurology. "There has been hope that [new drugs] will not only suppress seizures, but modify their consequences. [2DG] appears to be a novel treatment that offers great promise to achieve that vision."
About 1 percent of the world's population suffers from epilepsy, a neurological condition that makes people susceptible to seizures. Scientists believe that seizures, of which there are many kinds, occur due to sudden changes in how brain cells send electrical signals to each other.
2DG is essentially a more palatable version of the "ketogenic," or sugar-free, diets that some researchers have long recommended to epilepsy patients. Indeed, the notion of a sugar-free diet actually stretches back thousands of years to Biblical times, when healers sometimes prescribed starvation as a way to fend off seizures.
Unfortunately, ketogenic regimens can be a miserable experience. "The kids can't eat any sugar at all. Imagine no bread or Christmas cake," says Roopra. But 2DG would work as an effective substitute because it enters cells and clogs up certain cellular enzymes. As a result, the body cannot use its own glucose.
Though ketogenic diets seem to work in many epilepsy patients in whom existing treatments have been unsuccessful, scientists have struggled to understand the exact cellular connection between no sugar and no seizures. The UW-Madison work for the first time clears up some of that mystery.