LOS ANGELES, Jan. 27 (UPI) -- People who have had two brain injuries are more vulnerable than others to further traumatic brain injury, U.S. researchers say.
Repeat traumatic brain injury affects a subgroup of the 3.5 million people who suffer head trauma each year, but even a mild repeat traumatic brain injury while the brain is still recovering from an initial injury can result in poorer outcomes, especially in children and young adults.
Mayumi Prins, Daya Alexander, Christopher Giza and David Hovda of The University of California, Los Angeles, Brain Injury Research Center simulated single and repeat -- one or five days -- mild traumatic brain injury in rats and measured cerebral glucose metabolism.
They tested the hypothesis that the rats' brains would be more vulnerable to the damaging effects of repeat traumatic brain injury at one day post-injury, when glucose metabolism was still decreased, than at five days, when it had returned to normal levels.
The findings, published in the Journal of Neurotrauma, suggest the duration of metabolic slowdown in the brain could serve as a valuable biomarker for how long a child might be at increased risk of repeat traumatic brain injury.