Studies by doctoral student Renée Turner in the Discipline of Pathology at the University of Adelaide have shown that swelling in the brain seems to mimic a similar process in the skin, and may well be amenable to treatment with drugs, although these are yet to be developed.
"This potentially provides the first new clinical pathway to reducing brain swelling in 50 years," Ms Turner says. "It should improve the chances of survival after a stroke and reduce the risk of long-term disabilities."
About 48,000 episodes of stroke occur in Australia each year, one every 11 minutes.
Brain swelling or oedema is a common complication of stroke. It occurs when water accumulates in the brain, causing compression and eventually death of brain tissue. The mechanism in the brain is unclear. But in the skin, a similar process known as neurogenic inflammation is triggered by nerve cells. This results in increased leakiness of blood vessels and water accumulation in the skin tissue.
A compound known as substance P has been shown to contribute to this swelling in the skin, Ms Turner says. Blocking substance P reduces skin tissue oedema.
"Until recently, neurogenic inflammation was not known to occur in the brain following injury. Our laboratory has now shown that substance P is released during stroke. And blocking substance P receptors following stroke subsequently reduces brain swelling and improves outcome and survival in rats."