A new study has released new findings that athletes may develop memory loss due to being left unconscious after concussions.

The study was published in JAMA Neurology from the University of Texas Southwestern Medical Center in Dallas.

A relatively small study of retired National Football League (NFL) players. Athletes who lose consciousness after concussions may be at greater risk for memory loss later in life.

Researchers compared memory tests and brain scans for former NFL players and a control group of people who didn't play college or pro football. Recruited 28 retired NFL players living in Texas: 

• 8 diagnosed with mild cognitive impairment
• 20 who didn't appear to have any memory problems
• Aged 38-79 : avg. 58

All but three former athletes experienced at least one concussion and most typically had more than three. Researchers then compared these men to 27 people who didn't play football but were similar in age, education, and mental capacity to the retired athletes.

6 had cognitive impairment, betwee the ages of 41-77: Avg. 59 on average.

To assess memory and cognitive function, researchers gave participants a common verbal test. Measured how well they can recall lists of words and understand how the words are related. Athletes who had a concussion history as well as mild cognitive impairment got the lowest scores on this memory test.

After concussions that resulted in lost consciousness, the football players were more likely to have mild cognitive impairment and brain atrophy later in life. Results suggest that players with a history of concussion with a loss of consciousness may be at greater risk for cognitive problems in the future.

Researchers are trying to determine what individual risk factors are for this. In addition, brain scans in the study participants with mild cognitive impairment showed that the retired athletes had significantly smaller volume in the left hippocampus. Hippocampus: a region of the brain involved in memory. One drawback of the study is its reliance on players to report their own concussion history, can be very unreliable.