Chronic Traumatic Encephalopathy (CTE)

By Melinda Ma

Every 15 seconds, someone suffers from a traumatic brain injury, due to car accidents, contact sports, or simply getting hit in the head. Although most people survive, concussions should not be taken lightly, because they impair neurological function. The effects of concussions are cumulative, thus, repeated head injuries can result in chronic traumatic encephalopathy (CTE).

CTE is a progressive neurodegenerative disease that affects professional athletes in contact sports (football, boxing, soccer, etc.), military personnel, and victims of domestic violence. The repeated concussions that these people face cause eventual degeneration of brain tissue. Normally, tau proteins are found embedded among microtubules that act as the backbone of neurons and its axons. However, in CTE and other neurodegenerative diseases such as Alzheimer’s, tau proteins tangle together and cause the microtubules to fall apart, resulting in neuronal death. Degeneration begins in the hippocampus (memory center) and amygdala (emotional center), and then spreads throughout the cranium.

The most common symptoms of CTE include memory loss, aggression, depression, and impaired judgment. However, such symptoms may only appear within a period of years or decades after the last head injury. Because these symptoms are very similar to other neurodegenerative diseases, CTE is often misdiagnosed as Alzheimer’s or Parkinson’s disease.

Despite the millions of concussions occurring every year, there is still no clear method for detecting CTE in living people. In 2013, researchers from UCLA used radioactive markers to measure abnormal concentrations of tau proteins in the brains of five former NFL players. This was the first study performed on living CTE victims and serves as a significant step towards the diagnosis of CTE. With effective diagnostic testing, it may be possible to screen athletes and military personnel for early signs of CTE and provide ways to prevent and treat this condition.

References

1. Fainaru, Steve and Fainaru-Wada, Mark. “CTE found in living ex-NFL players.” ESPN: Outside the Lines. January 22, 2013. http://espn.go.com/espn/otl/story/_/id/8867972/ucla-study- finds-signs-cte-living-former-nfl-players-first-time
2. “What is CTE?” Brain Injury Research Institute. 2015. http://www.protectthebrain.org/Brain- Injury-Research.aspx