Researchers will be searching for signs of a degenerative disease in the brain of a former football star, who had requested such a study before he committed suicide last week.
Dave Duerson shot himself in the chest Feb. 17 after reportedly sending text messages to his family members requesting that his brain tissue be tested for the same damage seen in the brains of other retired NFL players.
Researchers at Boston University's Center for the Study of Traumatic Encephalopathy will comply with the request by Duerson, a four-time Pro Bowl safety who played for the Chicago Bears and New York Giants in their Super Bowl-winning seasons of 1985 and 1990, respectively.
Chronic traumatic encephalopathy (CTE) is a condition seen in football players, boxers and other athletes in which the brain slowly degenerates over time because of repeated blows to the head , said Christopher Nowinski, co-director of the center. Signs of the condition include memory and cognitive impairments, impulse-control issues and emotional problems.
Once the center's researchers receive Duerson's brain, they primarily will be looking for abnormal levels of a molecule called tau protein, Nowinski said.
"The presence of abnormal tau protein is a sign of CTE — it's toxic to the brain," Nowinsky said.
The researchers will measure the amount of abnormal tau protein and also look at the pattern of the protein's deposits in Duerson's brain, he said.
The search for signs of CTE
Abnormal tau is found in both CTE and in Alzheimer's disease, Nowinski said, but the pattern of deposits differs between the two conditions. In CTE, tau is primarily found in the surface regions of the cortex. If the wrinkly surface of the brain were a mountain range, Nowinski said, the brain of a person with CTE would have the highest levels of tau in the valleys. By contrast, in Alzheimer's disease, the protein is found deeper within the brain, and more evenly spread throughout.
Researchers know that head trauma initiates the tau deposits in people with CTE, whereas they don't yet know what brings about tau deposits in the brains of people with Alzheimer's .
The researchers at the center will examine Duerson's whole brain but will pay particular attention to the tau they find in the medial temporal lobe, the hippocampus and the amygdala, which plays a role in emotions, Nowinski said. These areas are believed to be among the most-affected in CTE.
The researchers will also look for other signs of physical trauma to the brain, such as contusions, but most of the signs that a person had developed CTE involve the microscopic findings involving tau protein levels, Nowinski said.
The work on Duerson's brain will be led by Dr. Ann McKee, a professor of neurology and pathology at the center, and could take months to complete, Nowinski said.
NFL players are getting involved
In recent days, other National Football League players have been contacting Nowinski asking about CTE, what they can do to help the center conduct its research, and how they might ward off the condition, Nowinski said.
"They are recognizing this is a serious issue with serious consequences," he said. Although CTE can be diagnosed only during an autopsy, living athletes can participate in studies in which researchers collect DNA samples and then contact the athletes once a year to administer cognitive tests and ask them about the details of any head traumas they've suffered.
"A lot of players are very concerned right now," Nowinski said. "Dave Duerson was very successful after playing. He was a leader in the community and well-loved. Players are thinking, if he could have it [CTE], anyone can."
The similarities between Alzheimer's disease and CTE may help researchers to find clues that will lead to treatments, Nowinski said. There are promising treatments being developed for Alzheimer's disease that may also prove effective in treating CTE.
Duerson's suicide is "one of many wake-up calls" to athletes and health policy makers about the dangers of head trauma , especially for young athletes, Nowinski said. In the United States, 1 in 4 boys plays a contact sport.
"They have the potential to seriously damage their brains if we don't start taking better care to avoid head traumas," he said.
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