Boston, Massachusetts – In an article published in the New England Journal of Medicine, medical researchers have achieved a possible breakthrough in the diagnosis of the chronic traumatic encephalopathy (CTE), a neurodegenerative illness, in living patients. While the medical researchers are cautious about its applicability, their achievement may well represent the revolutionary first step in a task that has eluded the scientific and medical communities since CTE was first discovered.
Several institutions including Mayo Clinic Arizona and Boston University were involved in the research. By using an experimental positron emission tomography (PET) scan, the researchers detected abnormal tau protein deposits in the brains of living former National Football League (NFL) players. The researchers also determined that the NFL subjects have higher levels of tau protein than non-football players of similar age.
Up until this research, doctors and other medical professionals were unable to detect abnormal tau deposits in living subjects. Instead, these deposits can only be examined in the brain after an individual’s death.
The PET scan is an imaging test that allows medical professionals to check for diseases in the body. The technology uses a special dye with radioactive tracers that can be swallowed, injected into a vein, or inhaled depending on the body part being examined.
The dense buildup of tau proteins in the body is associated with the wide range of behavioral and cognitive symptoms in people affected by CTE. The early symptoms include issues with impulse control, depression, and aggression, as well as decreased executive functioning, mild memory loss, and paranoia. These typically appear during the affected person’s 20s or early 30s.
The mood and behavioral symptoms are likely to appear first followed by the cognitive symptoms, which usually appear during the patient’s 40s or 50s. Every patient has a specific response to the disease, too.
While some patients will experience the behavioral and mood symptoms only, some patients will also experience both clusters of symptoms. Some patients may also have worsening symptoms over time regardless of whether they have suffered additional head impacts or not. Some patients may also have stable symptoms over several years before these become worse.
Former athletes particularly college and professional football players in the NFL have been plagued by these symptoms. The possible breakthrough in diagnosis in living patients can mean more effective CTE treatments may well happen in the near future.
While the researchers observed higher tau protein levels among subjects who have played football for years, they didn’t find a relationship between the subjects’ moods, behaviors, and cognitive test performance and these levels.
The researchers are quick to point out that their work isn’t a diagnostic tool. But it’s an advancement in terms of more effective and efficient individual assessments.
According to Chris Nowinski, the co-founder and chief executive officer of the Concussion Legacy Foundation, “It’s an exciting positive step toward a diagnosis in the living.” He further said that it’s important to tell others that while it may not yet be ready for patients, people who are at risk for CTE are excited about it and the progress being made by top scientists.
The research involved 26 former NFL players and 31 men of similar ages (from 40 to 69 years old). The former exhibited symptoms consistent with CTE while the latter didn’t have the symptoms or didn’t have a history of traumatic brain injuries.
The researchers used two types of markers. In one scan, they injected a flortaucipir marker into the subjects. The marker bonds with tau proteins and makes them visible under the scan’s cameras.
In the other scan, they administered an amyloid marker to the subjects. The marker makes the plaque buildup associated with another degenerative disease, Alzheimer’s disease, visible.
The researchers used both markers to suggest that the former football players’ symptoms weren’t likely caused by Alzheimer’s disease.
According to Dr. Robert A. Stern, the director of clinical research at Boston University’s CTE Center and the study’s author, “In this case, the tau PET scan showed elevations of taus in three primary areas of the brain compared to the control group, and those areas are consistent with where we’d expect to find abnormal tau in the postmortem evaluations for CTE.”
The research is among the latest study designed toward making an effective diagnostic CTE tool for living at-risk patients. Blood exams and MRI scans, among other technologies, have also been used for this purpose.
Furthermore, Dr. Stern emphasized that the finding is important but it isn’t the answer. Researchers are still a long way from their goal of finding a truly effective and efficient diagnostic tool.
Boston University’s CTE Center has plans of observing subjects longitudinally (i.e., across time) using data from an ongoing National Institutes of Health-funded study. The researchers will record the subjects’ symptoms and analyze their brains through the multiple images generated.
Dr. Harrison Martland first described CTE when he described a group of boxers with so-called punch drunk syndrome. In the ensuing years, several researchers added to the initial data but there were less than 50 cases were confirmed. In 2005, Bennet Omalu, a pathologist, published his findings on CTE in Mike Webster, a former NFL player. Since then, various organizations and institutions have been dedicated to finding effective diagnostic tools, causes and treatment for CTE.
