Concussion, a mild traumatic brain injury caused by a direct jolt or blow to the head or a hit to the body that causes the head to move violently back and forth, is most common among athletes. Evidence of concussion includes headache, confusion, loss of memory, dizziness, clumsiness and changes in mood. According to the Centers for Disease Control and Prevention (CDC), somewhere between 1.6 and 3.8 million sports-related concussions occur in the US every year.
A new study at the University of Texas Southwest Medical Center in Dallas supports the connection between concussion and long-term brain impairments. The study, published in JAMA Neurology and reported in Medical News Today, found that professional football players who experience concussion accompanied by loss of consciousness could be at higher risk for brain shrinkage in the hippocampus, resulting in memory problems later in life (https://www.medicalnewstoday.com/articles/294056.php).
The story in Medical News Today, written by Honor Whiteman, explains that neuropsychologist Munro Cullum, PhD, colleagues reached their findings by testing 28 retired National Football League (NFL) players. They enrolled 28 retired NFL players aged 36 to 79 years. Seventeen had a history of a grade 3 (G3) concussion with loss of consciousness, and eight had a history of concussion and had been diagnosed with mild cognitive impairment (MCI). They also enrolled 21 healthy individuals aged 21 to 77 with no history of concussion, MCI or football playing as controls, alongside six individuals with no history of concussion but who had been diagnosed with MCI. All participants underwent brain scans and took four tests to assess memory.
Retired NFL players with a history of concussion who had not been diagnosed with MCI scored worse on tests of verbal memory than control participants, though the scores were still considered normal. Former NFL players with a history of concussion and a diagnosis of MCI performed worse on verbal memory tests than both control participants and former NFL players without MCI. There were no differences in test scores between control participants with MCI and former NFL players with MCI.
According to the researchers, the volume of the hippocampus among former NFL players without concussion and loss of consciousness was similar to that of control participants across all age groups. The volume of the hippocampus among older retired NFL players with a history of at least one G3 concussion with loss of consciousness, however, was much smaller than that of control participants, while their right hippocampal volume was smaller than that of former NFL players without a G3 concussion. Former athletes with concussion and MCI had a smaller left hippocampal volume than control participants with MCI.
Even a single concussion can decrease in brain volume, according to a two-year-old study by researchers from New York University's Langone School of Medicine, as published in the journal, Radiology, and reported in The Huffington Post. That study, according to researcher Dr. Yvonne W. Lui, M.D., assistant professor of radiology and the neuroradiology section chief at NYU, found that people who had suffered a mild traumatic brain injury and experienced symptoms of the injury a year later also experienced brain shrinkage, specifically in regions linked with anxiety, memory and attention problems (https://www.huffingtonpost.com/2013/03/14/single-concussion-brain-volume-atrophy_n_2855549.html).