New research suggests playing high school football could cause brain changes even if the individual never suffers a concussion.
The findings back up concerns that have been raised on the effects sports have on the developing brain, the Radiological Society of North America reported.
"This study adds to the growing body of evidence that a season of play in a contact sport can affect the brain in the absence of clinical findings," said Christopher T. Whitlow, M.D., Ph.D., M.H.A., associate professor of radiology at Wake Forest School of Medicine and radiologist at Wake Forest Baptist Medical Center.
To make their findings the researchers looked at 24 high school football players between the ages of 16 and 18. All of the participants were monitored with the Head Impact Telemetry System (HITs) helmet-mounted accelerometers, which keeps track of the number of helmet impacts. The team used this data to measure "risk-weighted cumulative exposure."
The researchers used this information to sort the participants into two categories: heavy hitters and light hitters. The study included 15 light-hitters and nine heavy hitters, none of which experienced a concussion. All of these players underwent a tensor imaging (DTI) analysis, which identifies microstructural changes in the brain's white matter.
White matter is made up of axons that act like communication cables that connect different regions of the brain. Diffusion tensor imaging produces a measurement, called fractional anisotropy (FA), that looks at the movement of water molecules along axons. In healthy white matter this movement is fairly uniform, and irregular patterns suggest structural abnormalities.
The researchers found both groups demonstrated global increases of FA over tim, but the heavy-hitters showed areas of decreased FA in brain regions such as the splenium of the corpus callosum and deep white matter tracts.
"Our study found that players experiencing greater levels of head impacts have more FA loss compared to players with lower impact exposure," Dr. Whitlow said. "Similar brain MRI changes have been previously associated with mild traumatic brain injury. However, it is unclear whether or not these effects will be associated with any negative long-term consequences."
The findings were presented at the annual meeting of the Radiological Society of North America (RSNA).
