Getting your bell rung was once a badge of honor in sports. The ability to shake it off and not miss a play was accepted and routine. But it had been known for almost a hundred years that repeated hits to the head had long-term consequences and “dementia pugilista” was the term used for a punch drunk old fighter who had been hit in the head one too many times. The realization was slow in coming that the same injury to the brain could occur in football players, and that the most popular sport in the country could be a potential cause of psychiatric disturbances and early dementia.
A new term was born: Chronic traumatic encephalopathy (CTE) describes a gradual degeneration in brain function due to repeated head injuries that causes both concussions with symptoms and concussions that are asymptomatic (do not cause symptoms). Once the initial symptoms of concussion have faded, months and years later, new symptoms occur. CTE symptoms start slowly and creep up on the patient. Initially, there may be concentration and memory problems with episodes of disorientation and confusion, dizziness, and headache. It is as if the concussion symptoms were starting to return even without a new head injury. Emotions get labile and the patient can become aggressive and psychotic. As CTE progresses, behavior becomes even more erratic, with aggression and symptoms similar to those of Parkinson's disease. Finally, thought processes decrease even further, leading to a dementia with more Parkinson's symptoms including speech and walking abnormalities. The symptoms are progressive and cannot be stopped.
The diagnosis of CTE is tough to make clinically. No bleeding and or other major abnormalities are visible on CT scan and CTE appears to act like other diseases that attack brain function. It can be confirmed by autopsy and dissection of the brain but that doesn't particularly help the patient. An abnormal protein called tau builds up in the brain and causes abnormal nerve fibers and cell tangles. These abnormalities look different than those in an Alzheimer's brain in which loss of brain tissue is routinely seen.
Victims of CTE seem to be more prone to death because of alcohol or drug overdose and suicide. The suicide deaths of NFL football players Junior Seau, Ray Easterling, and Dave Duerson and NHL hockey players Derek Boogard, Wade Belak, and Rick Rypien have brought the specter of CTE and chronic head injury to the front page, but it isn't just these athletes who may be at risk. The correlation between boxing and CTE should be expected because the goal of the sport is to inflict a concussion upon the opponent, but what about soccer players or non-athletes who are unlucky enough to sustain repeated concussions?
CTE diagnosis is difficult. There is only supportive treatment, and the consequences of the brain injury include early death. It would seem that prevention is the best and only option at the present time, but that may be difficult when society approves of the violence on the football field and in the boxing ring. Young athletes see themselves as invincible and indestructible. The pursuit of short-term athletic glory overshadows the specter of long-term disability, especially when the symptoms may be delayed by decades. People may have righteous indignation about the situation, but for now it stops on Saturday when they cheer for their alma mater's colors and on Sunday when they cheer for their favorite NFL team.
McKee, Ann C., et al. "Chronic traumatic encephalopathy in athletes: progressive tauopathy after repetitive head injury." Journal of Neuropathology and Experimental Neurology 68.7 (2009): 709-735.