Subconcussive blows and soccer: what’s the headache?

As the fall sports ramps up, teen athletes across the country are donning shin guards and cleats, prepping to return to their beloved sport—soccer. A handful, however, are foregoing the ritual. One child sitting on the sidelines is the 13-year old daughter of Ken Reed, sports policy director of the League of Fans. Reed and his wife decided the risk of short- and long-term brain damage from subconcussive blows to the head outweighed the benefits of the sport. They pulled their daughter from the field, a decision Reed shared on this recent Huffington Post blog.

Thriving checked with William Meehan, MD, director of Boston Children’s Hospital Sports Concussion Clinic, to learn more about the science of subconcussive blows.

Studies seem to indicate a troubling trend. A research letter, published in the Journal of the American Medical Association in late 2012, compared MRI exams of the brains of soccer players to swimmers and found differences in white matter integrity. White matter contains nerve fibers and connects areas of the brain responsible for different tasks, such as attention and memory.

MRI exams also showed amateur adult soccer players who headed the ball more frequently had white matter abnormalities similar to those found in players who suffered concussions, researchers reported in another study in Radiology.

Such studies attract a lot of media attention and may prompt some parents to consider pulling their children from the field. “It’s a personal decision. We have to consider the benefits of playing vs. the risks involved and make a decision from there,” says Meehan.

However, studies detailing the dangers of subconcussive blows should be interpreted with caution, according to Meehan. Many include only a small number of athletes, and some did not control for previous concussions. That is, researchers did not determine if players who headed the ball more frequently also had more concussions, which may have confused the findings.

Lastly, findings on an MRI exam may not matter in the long run. “Are these MRI findings going to bother players later in life? We don’t know the answer to that. If a player has white matter abnormalities on an MRI, but lives to be 120 years old without any symptoms, do the MRI findings matter,” notes Meehan.

The early findings in these studies don’t seem to reflect historical experience. “Hundreds of thousands of people have played soccer through childhood, high school and college and ultimately died of a heart attack or something else that had nothing to do with their brains,” explains Meehan.

What’s more, conditions that are known killers, such as heart disease, high blood pressure, stroke and diabetes, can be reduced or prevented by exercise. Limiting a child’s opportunity for exercise because the activity might lead to a finding—a change in the appearance of white matter on MRI—with uncertain significance might have unintended consequences especially since sports participation during childhood instills lifelong patterns of exercise and brings psychosocial benefits.

Playing it safe

Concerned adults have proposed a variety of alternatives to keep kids on the field and safe.

William Meehan, MD

Some suggest protective headgear designed to shield the brain during heading. Meehan is not a fan. “There is no solid evidence that this gear will reduce risk of concussion. Often, when personal protective equipment like this is introduced into a game, play actually gets rougher, which could ultimately lead to an increased number of concussions, rather than fewer concussions.”

Others have suggested that heading should not be introduced until high school age. That also would be a mistake, according to Meehan. “A 17-year-old can kick a soccer ball hard, far and fast. The first time a player lines up to take a header should not be when the ball was kicked by a player who is that strong. Players may be much better off learning proper heading technique at a young age in a controlled setting where they can be taught the coordination, timing and strength needed for heading. Perhaps starting with a soft, Nerf-like soccer ball at a younger age would be preferable.”

A ‘wait and see’ approach may be just what the doctor ordered. “We need to pay attention to the issue of sport-related concussions and to subconcussive blows and determine if subconcussive blows have a cumulative effect on brain function.” Meehan recommends exercising restraint in making decisions based on preliminary studies.

And for parents panicked by the plague of concussions in girls’ soccer, Meehan puts the numbers in perspective. “The overall number of girls’ soccer players sustaining concussions is high because so many girls are playing soccer. The actual incidence of concussion in girls’ soccer, the number of concussions that occur per practice or game, is less than half the incidence in boys’ football, and substantially lower than boys’ ice hockey and lacrosse.”

To learn more about preventing concussions please download this Concussion Prevention guide