News Review From Harvard Medical School -- Brain-Disease Deaths High in Ex-NFL Players
Former pro football players are much more likely than average to die from brain diseases, a study finds. The study was done by the National Institute for Occupational Safety and Health (NIOSH). It was based on a 1994 study of 3,439 former NFL players. All had spent at least 5 seasons in the league. Researchers looked at death certificates for 334 players who died. They were 3 times as likely as the general public to die of diseases that damage the brain. Seven had Alzheimer's disease. Seven had amyotrophic lateral sclerosis (ALS, often called Lou Gehrig's disease). Death rates from those 2 diseases were 4 times average. Death rates from Parkinson's disease were average. Chronic traumatic encephalopathy (CTE), a disease long known to occur in boxers, has also been found recently in the brains of deceased NFL players. It is believed to be caused by repeated concussions. CTE symptoms can mimic Alzheimer's, Parkinson's or ALS. The new study could not say if any players who died had CTE. The condition can be found only on an autopsy. The researchers had to rely on death certificates. The journal Neurology published the study online September 5. USA Today wrote about it.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
I recently heard something startling about Lou Gehrig's disease: Lou Gehrig may not have had it.
An expert in brain injuries was being interviewed about chronic traumatic encephalopathy (CTE). This brain disease is caused by repeated concussions or other head injuries. It can cause symptoms quite similar to amyotrophic lateral sclerosis (ALS, commonly called Lou Gehrig's disease).
The expert speculated that Lou Gehrig may have actually had CTE, with symptoms that mimicked ALS. Gehrig was hit in the head and knocked unconscious at least four times during his baseball career.
ALS is a neurological disease in which muscles throughout the body become weak. Death is common within a few years of diagnosis. The cause is unknown.
Now there's more evidence of a connection between CTE and ALS. A new study of former professional football players has found that athletes diagnosed with ALS as well as Alzheimer's disease may have had these diseases at least in part because of CTE.
The new study appears in the journal Neurology. Researchers reviewed the causes of death of 334 former NFL players. Each had played at least 5 seasons between 1959 and 1988. The study found that:
- The risk of death from Alzheimer's disease or ALS was nearly 4 times as high as expected.
- Those who played a "speed" position (such as quarterbacks or receivers) had a risk of death from Alzheimer's disease or ALS that was more than 3 times the risk of those playing "non-speed" positions (such as linemen).
- The risk of death from Parkinson's disease did not appear to be increased among these football players.
This study suggests that repeated head injuries at high speed could cause brain disease years later that resembles ALS or Alzheimer's disease. However, this study relied on death certificates, not autopsies. Therefore, the researchers could not actually confirm the cause of death. So the relationship between CTE and later Alzheimer's disease or ALS remains uncertain. Still, the overall rate of these degenerative neurological diseases among professional football players is worrisome.
What Changes Can I Make Now?
If pro football players have higher than expected death rates from degenerative neurological diseases, it's reasonable to suspect CTE as a cause or a contributor. The dangers of CTE in athletes and others prone to head injuries (including soldiers) have become clearer in recent years. Studies suggest that CTE rates may be underestimated.
If you engage in activities that increase your risk of head injury, take precautions.
Perhaps the most common high-risk activity is riding in a car. Always wear a seat belt. Never drive while under the influence of alcohol.
Wear protective headgear or a helmet if your job or favorite pastime includes:
- Riding a bicycle or motorcycle
- Riding a horse
- Skiing or playing ice hockey
- Playing baseball (when batting)
- Playing football or lacrosse
- Working at a construction site
This is only a partial list. You can find other examples at the website of the Brain Injury Association of America (BIAA).
If you've had multiple head injuries or concussions in the past, it may be a good idea to avoid these high-risk activities in the future.
If you suffer a head injury, don't rush back into the action, especially if you have symptoms of:
- Headache or nausea
- Confusion or trouble concentrating
- Problems with vision
- Ringing in the ears
- Unexplained fatigue or mood changes
- Changes in sleep patterns
Get checked out before returning to work or the playing field. If you're not sure whether you're ready to return to action, don't rush back. Give yourself more time. If symptoms of head injury persist, see your doctor for evaluation.
What Can I Expect Looking to the Future?
You can expect to hear much more about the risks of contact sports and how to prevent head injuries. Some have predicted the demise of football because of recent reports of CTE among football players.
I'm not convinced that football as we know it will disappear any time soon. However, we have already seen changes in the rules to protect players from head injuries. More changes are likely in the future. I expect we also will see better protective gear.
Lou Gehrig played baseball, not football. If CTE turns out to be common in baseball or other sports, we'll need to figure out how to better protect players in these sports as well.
It's unlikely we can make every sport and occupation risk-free. But it does make sense to continue studying the link between degenerative brain diseases and head injuries. Progress in this area is urgently needed, especially for children and young adults, whose developing brains are particularly vulnerable.