Insidermedicine In Depth - June 1, 2011

Military personnel who experience brain injuries as a result of exposure to a blast may sustain a unique type of brain damage that involves injury to the axons, the long slender projections that nerve cells use to communicate with one another. This is the main finding of research published in the New England Journal of Medicine.

Outside of the military, common causes of traumatic brain injury include:

• Falls

• Motor vehicle accidents

• Being struck by or against something

Researchers from the Washington University School of Medicine in St. Louis used a special type of imaging, known as diffusion tensor imaging, to determine whether damage to the axons was present in the brains of 63 U.S. military personnel with a diagnosis of mild traumatic brain injury. These personnel had sustained head injuries as a direct result of being exposed to a blast as well as from an injury related to the blast, such as being hit in the head with a blunt object or falling. The results of their scans were compared with those of 21 military personnel who had also been exposed to a blast but did not have signs of brain injury.

The results of scanning were consistent with injury to the axons among those with a diagnosis of traumatic brain injury. Marked abnormalities in specific areas of the brain were found among those who had sustained brain injuries, compared with those who had not. Among 18 of the 63 injured personnel, a significantly greater number of brain abnormalities were found on scanning than would be expected by chance. Among 47 personnel who underwent a second scan 6 to 12 months after the first, persistent brain abnormalities were detected.

Today's research suggests that exposure to blasts as experienced by military personnel may produce a unique sort of brain injury. It remains to be seen what kind of long-term impact this sort of injury will produce and whether it will be different from more commonly seen traumatic brain injuries.

Category:

Science & Technology

Tags:

• military
• afghanistan iraq
• brain injury war damage axons