Whether it’s in adults or in children with clotting disorders or other conditions such as sickle-cell disease, a stroke can be likened to an atomic bomb. Just as ongoing radiation can do more damage than the bomb itself, the secondary damage of a stroke can devastate the brain.

In an ischemic stroke, accounting for nearly 90 percent of all stroke cases, it happens like this: When vessels supplying blood and oxygen to the brain are blocked by a narrowing or a clot, immune cells in the brain sense the low-oxygen conditions, suspect an invading organism and try to kill it by producing molecules known as reactive oxygen species or ROS’s. These, unfortunately, have an inflammatory effect that actually damages the brain further, injuring and killing neurons.

“Stroke produces inflammation, and that’s one of the main things people have been after in trying to reduce stroke damage,” says David Clapham, MD, PhD, chief of the Basic Cardiovascular Research Laboratories at Boston Children’s Hospital.

Right now there’s nothing that can do this. Most existing stroke drugs are aimed at preventing the stroke or dissolving blood clots once the stroke is happening – but they can’t deal with the aftermath. …