CTE Found in 99 Percent of NFL Players Studied

Chronic traumatic encephalopathy (CTE) may be more prevalent among football players than feared, according to a new study published in JAMA.

Researchers examined the brains of 202 deceased football players who donated their brains for research. Overall, CTE was diagnosed in 177 players — or 87 percent of those studied. That percentage increased significantly, however,  among National Football League players: 110 of the 111 NFL players had CTE, or 99 percent of the donated brains studied.

CTE is a progressive neurodegenerative syndrome associated with repetitive head trauma. It was discovered in 2002 by forensic pathologist Bennet Omalu, MD. While working in the county coroner’s office in Pittsburgh, Omalu performed an autopsy of “Iron Mike” Webster, the legendary Pittsburgh Steelers lineman who died at age 50. A Hall-of-Famer, Webster was known for his durability, never missing a game during a stretch between 1975 and 1986. He spent the last decades of his life struggling with dementia, delusions, paranoia, and explosive moods.

The study researchers also talked to the players’ families to collect detailed histories of their lives, traumatic brain injuries (TBI), and resulting symptoms. Among the 27 participants with mild CTE, 96 percent had behavioral or mood disorders or both; 85 percent had cognitive issues; and 33 percent had signs of dementia. Among the 84 participants with severe CTE, 89 percent had behavioral or mood disorders or both; 95 percent had cognitive issues; and 85 percent had signs of dementia.

The study has several limitations, the most important being that it is a skewed sample based on a brain-donation program — in other words, public awareness of a possible link between repetitive head trauma and CTE may have motivated players and their families with symptoms of brain injury to participate in this research. The authors stress that estimates of how prevalent CTE may be throughout football cannot be concluded or implied.

For our upcoming feature on CTE and traumatic brain injuries, we talked to Bennet Omalu, MD. Here’s what he had to say about the brain disease he discovered:

Experience Life |  Can you please define chronic traumatic encephalopathy for our nonscientific reader?

Bennet Omalu | Chronic Traumatic Encephalopathy, or CTE, is a major part of the traumatic encephalopathy syndromes, which arise when the human brain suffers blunt force trauma or acceleration–deceleration injuries. It is a type of brain damage, which can be permanent and progressive, and can be caused by repeated blows to the head over time in all types of human activities including sports. Single or episodic blows to the head like we have in motor-vehicle crashes, which result in severe brain injuries, can also cause CTE.

CTE manifests with a broad spectrum of symptoms, which may include but are not limited to mood disorders like depression, bipolar disorder, impulsivity, drug and alcohol abuse, loss of memory, loss of intelligence and language, loss of executive thinking, and other cognitive capacities.

EL | We often hear the generalized statement that “concussions cause CTE.” This seems to be both inaccurate and a generalization. From my understanding, CTE is caused by cumulative blows to the head — correct? And these blows can be both minor and major, from subconcussions to true concussions.

BO | Yes, CTE is not caused by concussions. Subconcussions and concussions are diseases by themselves, which are separate from CTE. Subconcussions and concussions belong to the acute traumatic encephalopathy syndromes. You can develop CTE without suffering a concussion.

CTE can be caused by a single blow to the head, episodic blows to the head, or repetitive blows to the head, with or without concussions, with or without helmets.

There is nothing like a safe blow to the head. In all that we do, we should avoid blows to the head.

EL | Do you think we will someday be able to diagnose CTE in living people?

BO | Yes, today, we can diagnose CTE in living people based on the manifesting symptoms and a history of exposure, but it will be a presumptive diagnosis, just like we do for other types of dementias. Definitive diagnosis remains with postmortem examination of the brain, just like for other dementias. However, we do not need a definitive degree of certainty to make a diagnosis in a living person.

So yes, we can now diagnose CTE in living people. But in the near future we can develop biological and radiological markers for CTE, which will be clinical-assessment tools that will aid the physician in a more definitive diagnosis of CTE in a living patient.

EL | And someday will we have a treatment, or even cure, for it?

BO | Yes, someday, I believe, we may develop a more definitive treatment modality for CTE, which can slow down the progression of the disease, or reduce the probability of suffering from the disease. I believe pharmacological agents will be more promising than technological devices.

EL | Knowing what we know now about repeated blows to the head, do you believe we should let our children expose themselves to activities that could damage their brains, like football, hockey, or boxing?

BO | No child under the age of 18 — which is when the brain becomes fully developed — should be allowed to participate in high-impact, high-contact sports, including boxing, American football, ice hockey, wrestling, mixed martial arts, and rugby. Children cannot join the military or vote, or drive a car, or sky-dive until they are 18.

For the less-contact, less-impact sports like soccer, we should take heading the ball out of the game for children under the age of 18, and children should not play soccer as we play it today until they are about 12 to 14 years old, when they have developed the motor and visuo-spatial neurological capacities that are required for complex, less-contact, less-impact sports like soccer and lacrosse. Children should engage in noncontact sports like track and field, basketball, volleyball, badminton, lawn tennis, swimming, table tennis, etc.

Knowing what we know now, we must protect our children from all types of intentional exposure to the risk of brain injury. High-impact, high-contact sports possess extremely high risks of brain injury. We should keep our children away from such risks.