New research reveals that subtle, distinct features in the brains of football players, identifiable on MRI scans, may help predict their long-term risk for developing neurodegenerative disease. A study led by researchers at NYU Langone Health found that specific grooves in the brain’s outer surface were structurally different in former football players compared to men who never played contact sports, offering a potential new biomarker for early detection.
The findings mark a significant step toward solving a major challenge in brain health: diagnosing chronic traumatic encephalopathy (CTE) in living individuals. CTE, a progressive disease linked to repeated head impacts, can currently only be confirmed through a postmortem autopsy by identifying a buildup of tau protein and brain shrinkage. By identifying anatomical differences in living players, scientists hope to develop tools that could one day assess risk and allow for intervention before irreversible damage occurs.
The Postmortem Problem
For years, the study of CTE has been limited to the examination of brain tissue after death. This has made it impossible to track the disease’s progression in real time or to understand why some individuals with a history of head trauma develop CTE while others do not. Autopsies of former athletes have revealed a characteristic pattern of pathology, including the accumulation of an abnormal protein called tau in the brain’s grooves, known as sulci, particularly near blood vessels. This buildup is associated with the degeneration of nerve cells and a reduction in overall brain weight, which manifests in symptoms ranging from mood swings and memory loss to severe dementia.
The effort to find a reliable diagnostic tool for living people is a critical goal for neuroscientists. Such a test would not only provide clarity for former players experiencing symptoms but could also inform safety guidelines and preventative strategies for current athletes. The development of biomarkers—measurable indicators of a biological state—is essential for this effort, with researchers exploring everything from blood tests to advanced brain imaging techniques.
Analyzing Brain Structure
The latest study, published in the journal Brain Communications, took a novel approach by focusing on the physical structure of the brain’s sulci. Investigators analyzed a single MRI brain scan from each participant to measure the width and depth of these grooves, which are known to be affected in confirmed CTE cases.
Study Participants and Methods
The research team recruited a large cohort of 169 former college and professional football players for the analysis. This group’s brain scans were meticulously compared to those from a control group of 54 men of similar age, weight, and education level who had no history of playing contact sports or serving in the military. By focusing on these specific anatomical features, the researchers aimed to determine if a history of repeated head impacts left a lasting, measurable signature on the brain’s topography that could be detected with widely available MRI technology.
Key Anatomical Findings
The analysis yielded two significant findings. First, former football players, on average, had shallower left superior frontal sulci compared to the non-athlete group. This groove runs along the top, front, left side of the brain, a region that previous postmortem studies have identified as being affected in CTE. Second, the study showed that the more years a former player had spent in the sport, the wider their left occipitotemporal sulcus became—a groove located along the left side of the brain. These sulci are very small, often no more than 1.5 millimeters wide, highlighting the subtlety of the detected differences.
A Potential Biomarker for Risk
Researchers believe these structural differences could be the first identifiable markers that distinguish brains at higher risk for CTE from those with lower risk. Senior investigator Hector Arciniega, an assistant professor at NYU Grossman School of Medicine, stated that the work shows that physical changes observed in postmortem brains can be applied to the brain scans of living people who are at increased risk. The ultimate goal is to incorporate these findings into a reliable diagnostic test that could be used before significant cognitive decline begins.
Identifying at-risk individuals early is crucial because CTE has no cure. Preventative and therapeutic strategies depend on understanding the severity of the risk. If validated in future studies, these sulcal measurements could be combined with other potential biomarkers to create a more comprehensive picture of an individual’s brain health after a career in contact sports.
Unanswered Questions and Future Work
Despite the promising findings, the researchers caution that a clinical diagnostic test based on these measurements remains years away. The study presented several limitations and raised new questions for investigation. For instance, it is currently unclear why the structural differences appeared only on the left side of the brain.
Interestingly, while the MRI scans revealed these anatomical distinctions, there were no corresponding differences between the groups on psychological tests measuring memory and learning. The study also did not find differences in other brain scan measures related to tau protein buildup. This suggests that the subtle changes in brain grooves may precede the more widespread damage and cognitive symptoms associated with later stages of CTE. Further research is needed to validate the findings and understand how these structural changes relate to the long-term clinical outcomes for athletes.
The Nature of CTE
Chronic traumatic encephalopathy is a neurodegenerative disease linked to a history of repeated head trauma, including both concussive and subconcussive impacts. While it is most famously associated with American football and boxing, it has been found in athletes from a wide range of contact and collision sports, including ice hockey, soccer, and rugby, as well as in military veterans exposed to blasts.
The symptoms of CTE often do not appear until years or even decades after the initial injuries. They typically progress over time and are categorized into two main forms. An earlier form, appearing in a person’s late 20s or 30s, can cause behavioral and mood issues such as depression, impulsivity, and aggression. A second form tends to emerge later in life, around age 60, and is characterized by memory and thinking problems that can advance to dementia.