Overview

Overview

There has been increasing recognition of the long-term neurological complications that can occur in those exposed to repeated head trauma, not only athletes, but also in the civilian and military population. And given the numbers of people that participate in sports and the military, this is a far-reaching public health issue.

It has been known for decades that boxers are particularly susceptible to develop “punch drunk” syndrome (now called chronic traumatic encephalopathy or CTE), parkinsonism or dementia. An important gap in our knowledge of the consequences of cumulative head trauma is how these brain disorders evolve and how early can they be detected.

Cleveland Clinic Lou Ruvo Center for Brain Health has been involved in two major research initiatives regarding long term effects of repetitive head trauma. The Diagnose CTE study, involving retired National Football League players, and the Professional Athletes Brain Health study are both focused on determining methods to recognize/diagnose individuals who may have CTE and identifying potential risk factors.

Closing the Gap

Since the first participant was enrolled in 2011, Cleveland Clinic’s Professional Fighters Brain Health Study — now known as the Professional Athletes Brain Health Study (PABHS) — has become a landmark longitudinal, observational study of athletes exposed to repeated head impacts (RHI) and the first to study retired and active men and women professional athletes concurrently.

PABHS is aimed at understanding the long-term effects of RHI, including means to detect accumulating brain injury early and factors that put certain individuals at higher risk — or protect them from — developing CTE.

PABHS researchers continue to diversify the cohort of athletes to include more women, retired athletes and bull riders, as well as recruit additional athletes from other sports, such as hockey and motor sports.

More than a decade later, researchers have made several advancements in our knowledge of CTE, including:

  • Development of new research criteria for Traumatic Encephalopathy Syndrome (TES) that will allow us to diagnose living people with symptoms that are suggestive of CTE (though CTE remains diagnosable only via autopsy).
  • Establishing the pathological hallmarks of disease — aggregates of tau around blood vessels deep within the folds of the brain.

Other notable findings from this research include:

  • Subtle effects of RHI on brain structure can be seen in some athletes within a year and can be tracked over time. The areas that we see change differ between people who are actively exposed to RHI compared to those who are retired and no longer exposed. This finding implies that there may be different pathological processes occurring in the brain in those who are active and those who have retired.
  • Certain proteins that are indicators of inflammation and cellular damage can leak out of the brain and can be measured in the blood. One particular protein, glial fibrillary acidic protein or GFAP, may be useful in detecting ongoing brain injury.
  • Individuals who began the study actively competing in combat sports and who then retire can show improvement or stabilization in both biochemical and clinical measures of brain function, suggesting the brain has the potential to repair.
  • The Repetitive Head Impact Composite Index has been created as a tool that is sensitive to the common cognitive and behavioral changes seen in individuals exposed to RHI and may be used to monitor response to therapies as we begin clinical trials in CTE.
  • The risk of brain injury differs between various combat sports (e.g., MMA, boxing, martial arts) as measured by cognitive performance (memory, thinking and speed of completing cognitive activities) and certain brain volume.

Contact Information

Charles Bernick, MD, MPH
702.675.5237

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