Researchers Searching for Ways to Prevent Mysterious Form of Dementia
November 5, 2012
by Robin Tricoles
The Journal of the American Medical Association first described the long-term effects of repetitive brain trauma in a 1928 article titled “Punch Drunk.” The piece described the cognitive and behavioral impairments seen in prizefighters. Since that paper’s appearance, various terms have been used to describe the disorder, including “dementia pugilistica,” and more recently, chronic traumatic encephalopathy or CTE. However, scientists still know relatively little about the disease.
What is known though is that CTE is a progressive brain disease, similar to Alzheimer’s and other related neurodegenerative diseases, but it’s also unique neuropathologically. It affects not only boxers but football players, hockey players, soccer players, military veterans, and even victims of domestic violence.
“It’s a very, very big deal in our veterans returning from Afghanistan and Iraq because of the repetitive exposure to blast injuries in addition to their previous exposure to brain trauma from playing sports,” says neuropsychologist Robert Stern, co-founder of the Center for the Study of Traumatic Encephalopathy at Boston University. “And it’s potentially a huge issue with millions of kids playing contact sports. It’s really something that needs to be looked at scientifically in the speediest fashion.”
CTE is sparked by a history of repetitive brain trauma, that is, concussions and subconcussive blows occurring early in life. Concussions occur when a person suffers a blow that rattles around the brain inside the skull and leads to changes in the functioning of brain cells. With concussions come associated symptoms. In contrast, subconcussive blows can be just as damaging but aren’t accompanied by symptoms.
So, once the disease is set in motion through repetitive brain trauma, it continues to harm brain tissue even after the trauma has ceased. When enough brain tissue is affected symptoms begin to appear. Eventually, dementia occurs.
Although every confirmed case of CTE has a history of exposure to repetitive brain trauma that doesn’t mean everyone who repeatedly experiences brain trauma will get the disease. “The repetitive brain trauma seems to be a necessary variable but not a sufficient variable in developing CTE,” says Stern. “So we need to figure out what other risk factors lead one person to get the disease and another person not to get it.”
Which is exactly what Stern is doing. Stern interviews relatives of those who have died and undergone neuropathological examinations that confirm CTE. He asks relatives to recount their family member’s lifelong behavioral traits and cognitive functioning so he can put together a temporal picture of the disease’s symptoms, such as changes in memory and judgment, impulse control, irritability, agitation, violent behavior, depression, and suicidal ideation. Stern has also received funding from the National Institutes of Health to develop objective biological markers of CTE so that it can be diagnosed during life rather than post-mortem as it currently is.
“Once we can diagnose the disease during life, we’ll be able to do so much more, says Stern. “It’s important to understand the risk factors, to be able to understand how common it is, and to be able to start developing treatment interventions and ways to prevent it.”
Robert Stern, PhD, is a professor of neurology and neurosurgery at Boston University School of Medicine. Stern is the Director of the Clinical Core of the NIA-Funded BU Alzheimer’s Disease Center (ADC) and the Co-Founder of the Center for the Study of Traumatic Encephalopathy. He is a fellow of both the National Academy of Neuropsychology and the American Neuropsychiatric Association. For more information about Robert Stern, please visit his profile page at Boston University.