A concussion is a serious injury to the brain resulting from the rapid acceleration or deceleration of brain tissue within the skull. Rapid movement causes brain tissue to change shape, which can stretch and damage brain cells. This damage also causes chemical and metabolic changes within the brain cells, making it more difficult for cells to function and communicate.
The CDC estimates as many as 3.8 million concussions occur in the U.S. annually through sports and recreational activities, but only 5-10% are recognized and eventually diagnosed by coaches, parents, and athletic trainers. Surveys of high school athletes after the season find that 20% had concussion symptoms after a head impact at least once over the course of the last season, and over 50% of the contact sport athletes report at least one event in their career.
Recovering from concussion means re-balancing a delicate combination of chemicals within brain cells. This process takes a lot of energy, so it is important to conserve energy during recovery. When properly managed, the majority of concussion symptoms will resolve within a couple of weeks, however over-exertion of brain cells during recovery can cause symptoms to persist for months or even years. A significant percentage (estimates vary between 10% and 30%) of concussion patients suffer from extended recovery, known as post concussion syndrome.
Catastrophic re-injury: Second Impact Syndrome
During recovery, the brain is more vulnerable to re-injury. In rare cases, a second concussion sustained during recovery can cause the brain to undergo massive swelling. This extremely rare condition is known as Second Impact Syndrome (SIS). Approximately half of SIS patients die from their injuries, and the survivors often suffer from life-long catastrophic disability.
A preventable epidemic
The good news is we can stop concussions before they happen. There are many opportunities to reduce concussions through smart policy decisions. Research has shown over half of all head impacts and concussions in football occur during practice; in middle school soccer players there are 100,000 concussions caused by heading every three years. In 2012, the Concussion Legacy Foundation led a movement to reduce hitting in football practices at the youth through professional levels. Through our Safer Soccer campaign, we are now focused on delaying heading in soccer until high school. There is still a lot to do to make sports safer for all athletes and the Concussion Legacy Foundation will continue to be on the forefront of research and education.