A new study, published in JAMA Neurology, contributes to evidence supporting an association between brain injuries and long-term memory impairments by showing former National Football League (NFL) players who lost consciousness related to a concussion show unique differences in brain structure later in life.
In a study the researchers, comprised of neurologists and neuropsychologists at UT Southwestern Medical Center and the Center for BrainHealth at UT Dallas, say is the first of its kind, researchers found the hippocampus, a part of the brain which helps regulate memory, was found to be shrunken in 28 former NFL players compared to a control group of men of similar age and education.
“This is a preliminary study, and there is much more to be learned in the area of concussion and cognitive aging,” said Dr. Munro Cullum, Professor of Psychiatry and Neurology and Neurotherapeutics at UT Southwestern, a co-author of the study. “While we found that aging individuals with a history of concussion and loss of consciousness showed smaller hippocampal volumes and lower memory test scores, the good news is that we did not detect a similar relationship among subjects with a history of concussion that did not involve loss of consciousness, which represents the vast majority of concussions,” said Dr. Cullum.
According to the findings, some of the retired football players met the criteria for Mild Cognitive Impairment (MCI) as well. MCI has negative effects on memory and may potentially lead to dementia. The researchers note the findings were most pronounced among those with a more severe history of concussions.
The former players included in the study ranged in age from 36 to 79 years old, with a mean age of 58. The researchers compared the results from these players against 21 healthy men of similar age, education level, and no history of brain injury.
While the results do show athletes with more serious concussions had notably shrunken hippocampus volume, but the reason why is unclear. Some shrinkage may be related to natural aging processes, but the accentuated reduction in volume were most linked with individuals who suffered a serious brain injury that included loss of consciousness.