Football is a violent sport. Although most football-related injuries heal, one particular injury — concussion — may lead to major mental issues later in life.
A new study found that concussions with loss of consciousness may affect the structure and function of the brain in former National Football League (NFL) players.
"Our findings suggest that a remote history of concussion with loss of consciousness is associated with both later-in-life decreases in hippocampal volume and memory performance in retired NFL players," wrote lead study author Munro Cullum, PhD, of the University of Texas Southwestern Medical Center in Dallas, and colleagues.
Dr. Cullum and team studied 28 former NFL players between October 2013 and August 2014. Of these patients, eight were diagnosed with mild cognitive impairment (MCI).
Patients with MCI may have problems with memory, language, thinking and judgment — beyond what is typically seen as one ages.
Two control groups were used in this study. The first involved 21 patients without MCI who had no history of concussion or involvement in football. The second involved six patients with MCI who had no history of concussion. All study patients were between 36 and 79 years of age.
A concussion is a brain injury that usually occurs after a blow to the head and may impair brain function.
Dr. Cullum and team found that 17 of these former NFL players had a history of grade 3 concussion(s). A grade 3 concussion involves loss of consciousness.
These former NFL players scored lower overall on verbal memory tests — compared with patients without MCI. And players with MCI scored lower than players without MCI.
Dr. Cullum and team also found that players with a past grade 3 concussion had smaller hippocampal volumes — compared with patients without MCI. As the ages of these former NFL players increased, hippocampal volume decreased further.
The hippocampus is a part of the brain that plays a role in memory and emotion.
Dr. Cullum and team found that all of the former NFL players older than 63 — who had a past grade 3 concussion — were diagnosed with MCI.
Exactly how loss of consciousness leads to MCI and hippocampal damage is not known.
This study was published online May 18 in JAMA Neurology.
The National Institute on Aging and the BrainHealth Institute for Athletes funded this study. The authors disclosed no conflicts of interest.