Chronic Traumatic Encephalopathy Similar To Alzheimer’s Disease
Neurodegenerative disease is surging around the world. Many cases are caused by the buildup of neurotoxins in our brains. In some cases, the build up of neurotoxins is sparked by traumatic brain injury, including concussions.
Research on chronic traumatic encephalopathy (CTE) and contact sports is still in its early stages, but a growing body of evidence suggests that there is a link between the two. One of the most compelling pieces of evidence comes from a study published in the journal JAMA Neurology in 2017. The study examined the brains of 111 deceased former NFL players. It found that 110 of them had CTE.
Other studies have found that CTE also is common in other contact sports, such as boxing, hockey, and rugby. A 2019 study published in the journal Brain found that 99 percent of former professional boxers who died from natural causes had CTE.
A new study from the CTE Center at Boston University’s discovered more than 60 cases of chronic traumatic encephalopathy, known as CTE, in athletes who were under the age of 30 at the time of their death. This is the largest study to look at the neurodegenerative disease in young people.
Researchers found about 40 percent of the brains studied had developed some of the earliest signs of the disease, which is associated with repeated head trauma.
The study includes the first case of an American female athlete diagnosed with CTE.
The report, published in JAMA Neurology, describes the features of 152 brains donated between February 1, 2008, and September 31, 2022, to the UNITE brain bank — the largest tissue repository in the world focused on traumatic brain injury and CTE. Sixty-three out of the 152 donated brains (41 percent) had autopsy-confirmed CTE.
The disease can only be formally diagnosed with an autopsy and has been associated with memory loss, confusion, impulse control problems, aggression, depression, impaired judgment and suicidal behavior. Unlike past studies, which looked at CTE primarily among professional American football players, the majority of the athletes diagnosed in this study were amateur athletes who played at the youth, high school, and college levels.
“This study clearly shows that the pathology of CTE starts early,” said Dr. Ann McKee, coauthor of the study and director of the Boston University CTE Center. “The fact that over 40 percent of young contact and collision sport athletes in the UNITE brain bank have CTE is remarkable,” adding that community brain bank studies show that fewer than 1 percent of the general population has CTE.
McKee said that all of the brains included in the CTE study were donated for a reason.
“The study is not a general population study. It’s not a prevalence study,” she said. “We get brain donors who are very symptomatic, and that’s why the family pursues brain donation.”
CTE is an Alzheimer’s-like disease has been most commonly associated with former professional football players, but has also been detected in military veterans, including many who have been exposed to roadside bombs and other types of military blasts.
Previous studies have shown that repetitive hits to the head — even without concussion — can result in CTE. Brain trauma produces neurotoxins known as tau–a form of prion that essentially consumes the brain.
Most of the donors analyzed in this recent study played football (60 percent), followed by soccer (15 percent) and ice hockey (10 percent). Other sports included in the study that resulted in CTE diagnosis are amateur wrestling, rugby and professional wrestling.
The donors’ ages at the time of death ranged from 13 to 29 years old. The youngest person diagnosed with CTE in the study was a 17-year-old high school football player.
Brain donors who died before they reached 30 were selected to minimize any contribution from age-related conditions.
Researchers are still trying to understand the exact relationship between CTE and contact sports. However, it is thought that the repeated head injuries that athletes experience in contact sports can damage the brain and lead to the buildup of tau proteins (a deadly form of prion), which are the hallmark of CTE.
“The next step is to determine if CTE is a prion disease,” said Gary Chandler, CEO of Crossbow Communications and author of the eBook below. “The clinical term for prion disease is transmissible spongiform encephalopathy (TSE). The operative word is ‘Transmissible.’ Are caregivers–friends and family–at risk when exposed to someone with CTE? Or when exposed to someone with Alzheimer’s disease, Parkinson’s disease or CJD? The science on prion disease is being ignored.”
Not all athletes who play contact sports will develop CTE. However, the more head injuries an athlete experiences, the higher their risk of developing CTE.
Another important facet of the study is that amateur athletes comprised 71.4 percent of those diagnosed with CTE. Of the 48 donors diagnosed with CTE who played football, 37 were amateur football players and 11 played for the NFL. Position played made no difference in developing CTE, but those who played longer were more likely to be diagnosed with the disease. On average, those that had CTE played football for 2.8 years longer than those that didn’t develop the disease.
“It’s become fairly well recognized that CTE is a risk for high-level elite athletes, especially football players,” McKee said. “But it does show that CTE can start in very young athletes who only play amateur sports.”
In a study published earlier this year, BU’s CTE Center found nearly 92 percent of 376 former NFL players studied were diagnosed with CTE.
Due to a lack of data, McKee said it is unclear if CTE is more common in men than in women. Only 11 of the total 152 brain donors evaluated in the new study were female, including one positive diagnosis, a 28-year-old collegiate soccer player who was not identified. Earlier this year, scientists in Australia diagnosed the world’s first case of CTE in a professional female athlete, Heather Anderson, an Australian Football League player had low-stage CTE confirmed by autopsy.
The neurodegenerative brain disease CTE can be found in people who have been exposed to repetitive head impacts. McKee says the largest amount of damage seen in athletes diagnosed with CTE was found in the frontal lobe.
“The frontal lobe is very important for judgment, and attention. It’s also important for things like what we call executive function, planning and organizing. It may play a role in impulsivity,” she said.
During analysis, McKee and her team also saw structural changes to the brain. McKee noted there were also some suggestions of atrophy or shrinkage of the brain in those people diagnosed with CTE because their ventricles — cavities within a brain’s interior — were slightly dilated, indicating that they likely lost some brain volume.
In the new study, clinical symptoms appeared in all of the athletes regardless of whether they had CTE, including depression, difficulty controlling behaviors and problems with decision-making. Substance abuse also was frequent, with alcohol abuse present in 43 percent of donors and drug abuse in 38 percent.
The study shows that 87 of the 152 donors died by suicide, including 33 donors who also had CTE. Although CTE can only be diagnosed after a person has died, McKee said it is important for athletes to treat the symptoms regardless of whether they stem from the disease.
Researchers are working on a number of different fronts to learn more about CTE and contact sports. Some of the areas of current research include:
- Developing better diagnostic tests for CTE. Currently, the only way to definitively diagnose CTE is through an autopsy. Researchers are working on developing less invasive diagnostic tests that can be used while a person is alive.
- Learning more about the causes of CTE. Researchers are trying to understand the exact role that head injuries and other factors play in the development of CTE.
- Developing treatments for CTE. There is no cure for CTE, but researchers are working on developing treatments that can help to slow the progression of the disease and manage the symptoms.
There are many things that athletes can do to reduce their risk of developing CTE:
- Wear proper protective gear. This includes helmets, mouth guards, and other equipment that can help to reduce the impact of head injuries.
- Learn proper tackling and blocking techniques. This can help to reduce the risk of head injuries during contact sports.
- Take breaks from contact sports. This can help to give the brain time to recover from any head injuries that may have occurred.
- Seek medical attention immediately if you experience any head injury. This is important for getting a diagnosis and treatment as soon as possible.
It is also important to note that there is no safe level of head injury. Even a single head injury can increase the risk of developing CTE. Therefore, it is important to take steps to protect yourself from head injuries, regardless of whether or not you play contact sports.
