Brains of Athletes With a History of Concussion Show Changes Years Later

A new study has found that college athletes with a history of concussion had changes in the size, blood flow, and connections in their brains months and even years after the injury.

“Sport concussion is still considered to be a short-term injury, but this study provides further evidence of brain changes that may lead to long-term health consequences, including the risk of re-injury, depression, and cognitive impairments,” said Nathan Churchill, the study’s lead author and a post-doctoral fellow in the Neuroscience Research Program at St. Michael’s Hospital in Toronto.

“We expect to see changes in the brain right after an acute injury, but in this study we saw physical differences in brains of athletes that were scanned months to years after their last concussion.”

The study looked at male and female varsity athletes in seven different contact and non-contact sports, demonstrating the relevance of the findings for the overall sporting community, not just traditional high risk sports such as hockey and football, the researchers noted.

Published in the Journal of Neurotrauma, the study used advanced Magnetic Resonance Imaging (MRI) to comprehensively describe abnormalities in brain structure and function in 43 varsity athletes at the start of their sports seasons — 21 male, 22 female, 21 with a history of concussion and 22 without.

The researchers found the athletes with a history of concussions had:

  • Brain shrinkage in the frontal lobes, the part of the brain involved in such things as decision-making, problem solving, impulse control, and the ability to speak fluently. The brains of athletes with prior concussions showed a 10 to 20 percent reduction in volume compared to those with no concussions.
  • Less blood flow (25 to 35 percent) to certain areas of the brain, mainly the frontal lobes, which are very vulnerable to injury because of their location at the front of the brain. Reduced blood flow is associated with a longer recovery
  • A greater number of concussions was associated with reduced brain volume and blood flow.
  • Changes in the structure of the brain’s white matter, the fibre tracts that connect different parts of the brain.

Behaviors controlled by the frontal lobe, such as impulse control and problem-solving, are often impaired in older athletes with a history of repeated head injury. These findings suggest that this area of the brain may be affected even for young, healthy adults with few concussions, according to the researchers.

“We want to emphasize that, in general, the health benefits of sport participation still outweigh the risk of concussion,” said Dr. Tom Schweizer, head of the Neuroscience Research Program and a co-author of the paper. “Our findings can help to guide concussion management, and to minimize any future risk to athletes. The more we know about concussion, the better we can reduce these risks.”

Source: St. Michael’s Hospital
Photo: University athletes with a history of concussion had changes in the size, blood flow and connections in their brains months and even years after the injury — changes not seen in athletes without prior concussions, according to a new study by researchers at St. Michael’s Hospital. Shown here is Dr. Tom Schweizer, co-author of the study. Credit: Courtesy of St. Michael’s Hospital.