The long-term damage from severe brain injury, whether caused by accident or assault, can be reduced by injecting a simple polymer - polyethylene glycol, or PEG - into the blood stream.

Researchers at Purdue University in the US found that a solution of PEG significantly reduced the impact of trauma on the brain of laboratory rats, if administered within four hours. PEG seems to work by sealing and repairing damaged cell mechanisms. The results appear in the Journal of Biological Engineering.