For those lucky enough to have the first signs of
recognized by friends or family, things often get very quiet very quickly as 911 calls are made, gurneys are wheeled in and tests are conducted.
says that if rats are any guide to human health (and they often are the starting point for new treatments), stroke victims might do a lot better with a quick dose of stimulation instead.
At his lab, Frostig had long noticed that a rich sensory environment appeared to make rats not only happier but much healthier. Studying models of stroke in rats, Frostig sought to mimic the effect of a
by tying off the
, which feeds oxygenated blood to a broad swath of cerebral cortex, and then severing it. When he put these rats back into cold, sterile cages, they developed terrible disabilities, as parts of their oxygen-starved brains died, taking neighboring brain cells with them.
But when these rats went back to a rich environment with toys to play with, tunnels to dig and food to find, even severing one of the brain's most important arteries was not enough to create apparent stroke damage.
This week at the annual conference of the
, Frostig and his colleagues presented new research showing the profoundly protective effect of early stimulation in preventing stroke damage. Rats who have had a single whisker stroked for five minutes in the two hours after their middle cerebral artery is severed emerged from the experience completely free of brain damage. In another experiment, rats were treated with intermittent auditory stimulation after the blockage of blood flow to, among other regions, the brain's auditory cortex. Those rats, too, survived their strokes with brain function completely intact.
In both cases, the nature of the stimulus -- tactile and auditory -- corresponded to some part of the brain that was being denied blood flow (the sensory cortex is among the
nourished by the middle cerebral artery).
The purposeful stimulation of those brain regions "induces massive redirection of blood flow that results in reperfusion and therefore protection of the ischemic area," Frostig's group concluded. In other words, when challenged to make sense of some incoming stimulus, parts of the brain cut off from their blood supply somehow signal their urgent need for oxygen and fuel, and blood carrying those requirements finds another route to get there.
When it comes to preventing brain damage from an ischemic stroke (the kind in which blood flow is blocked, representing 88% of all strokes), neurologists say "time is brain": Getting a victim to a hospital for treatment quickly makes it possible to reduce brain damage and disability. But only a tiny fraction of patients -- fewer than 1 in 10 -- get to the hospital in time to get
that could reduce damage.
So if, immediately after a stroke's onset, a stroke victim's friends, family or first responders could follow a simple strategy to help protect his or her brain cells from dying, that would be very useful. "Anything that would activate neurons in the ischemic area should work," Frostig says.
A few caveats -- and they are major. For starters, this research on rats may not translate to humans at all. If it does, the time frame during which stimulation might be helpful -- whether it