Sports like hockey and football are often thought of when we think about the danger of concussions in athletes. Researchers have been looking at soccer as well.
Bruce Murray, a former soccer player who retired in 1995 following multiple concussions. CTE has been linked to concussions, but researchers now believe that smaller repetitive hits to the head could also be to blame.
Stealth disease is not curable and can only diagnosed after death. CTE can cause memory problems, trouble organizing simple activities and behavior changes such as a lack of motivation and short temper.
Murray, who reached the top of his game in 1990 was a strong player at Clemson University and then played forward for Team U.S.A. His aggressive play often left him with stars, as he was caught in the head by a Saudi player.
He said, "I was on my hands, knees, trying find my equilibrium, but for six weeks to a monthly, I would go to places and not understand why I was there," to CBS News' chief medical correspondent Dr. Jon LaPook.
Murray, at the age of 29, decided to hang up his sneakers because he was still experiencing post-concussion symptoms such as lightheadedness, headaches, and lack of sleep.
He said, "My body just felt beat up."
Two years ago, CBS News visited Murray in Maryland to see if he had any memory problems. One of these lapses left him particularly shaken. He was waiting in his car for his son and wife to return from the store when they arrived and didn't recognize Lynn, his wife.
Murray had a history of concussions and the couple reached Boston University's Center for Chronic Traumatic Encephalopathy (also known as the CTE Center). CTE can only diagnosed after death. Researchers scanned Murray's skull for clues and found one: his brain tissue was atrophied or shrinking.
Director of the CTE Center Dr. Ann McKee has examined hundreds of brains from athletes and veterans, including Aaron Hernandez, a football player who committed suicide while serving a life sentence. Concussions aren't the only cause of CTE. She warns that damage from asymptomatic hits can accumulate over time, increasing the risk of developing CTE.
McKee believes that the risk of injury to the head from playing soccer is alarming and that there are good reasons for stopping. McKee says that 13 million children in America play soccer. He believes more must be done to protect all athletes.
She said that the balls come from a great distance and at a high velocity. This impacts the head and causes injuries later.
U.S. Soccer governs the sport from kindergarten to the elite level. It has extensive protocols for concussion and bans or limits headers in children under 13. U.S. Soccer said it is still investigating sub-concussive hits among older players. We asked for an interview on-camera but the organization declined.
Murray stated that his condition is stable but that he still struggles with balance, memory, focus, and concentration. Murray still loves coaching youth soccer but feels that the sport needs to be safer for all.
Murray stated, "I believe U.S. Soccer must address this." It's known as football around the globe. What if the rules were rewritten? Is it necessary to "head the ball?"