Chronic traumatic encephalopathy [1] (CTE) is one of the most dangerous neurological conditions athletes can face, in part because there's still very little known about the disease. One of the most notable cases occurred in Aaron Hernandez [2], the ex-NFL star whose troubled life, crimes [3], and untimely death [4] are the subject of a Netflix documentary, Killer Inside: The Mind of Aaron Hernandez. But Hernandez is far from the only athlete to suffer from CTE, and research shows that it's not just athletes who are at risk. Experts are working to better understand the condition — and hopefully, find ways to diagnose and treat it sooner — but in the meantime, here are the answers to a few of the most important questions you may have about it.
What Is CTE?
Chronic traumatic encephalopathy (CTE) is a degenerative brain disease, which is associated with repeated head traumas [5]. The Mayo Clinic notes that CTE cannot be formally diagnosed until the brain is examined during an autopsy [6].
What Types of Athletes Are Most Likely to Develop CTE?
According to the Concussion Legacy Foundation, CTE is typically caused by repeated hits to the head [7] — in many cases, this means hundreds or thousands of traumas — over the course of a person's life. While CTE is often associated with concussions, smaller hits may collectively be even more damageing. Full-contact sports are the biggest culprits. Football, wrestling, and boxing are the most obvious, but other sports — such as hockey, football, and rugby — have been linked with CTE as well. And it's not just athletes: military vets who were exposed to repeated explosions or otherwise injured in combat have also been diagnosed with CTE.
What Are the Symptoms of CTE?
Boston University's CTE Centre, which has led the way in researching the condition, lists the following as the most common symptoms of CTE [8]. "In most instances, the clinical symptoms of the disease begin after a long period of latency [9] ranging from several years to several decades," the researchers wrote in an analysis published in 2014, noting that once they appear, the symptoms progress slowly and subtly over a period of many years.
- Memory loss
- Confusion
- Impaired judgement
- Impulse control problems
- Aggression
- Depression
- Anxiety
- Suicidality
- Progressive dementia
Are There Stages of CTE?
The team of researchers at Boston University, led by neuropathologist Ann McKee, MD, describes four stages of CTE [10], each marked by further degeneration and, usually, worsening symptoms. For example, people in Stage 1 may experience headaches and struggle to concentrate, while those with Stage 4 may suffer from dementia and show aggression. Hernandez was famously diagnosed with Stage 3 CTE [11] following his death at age 27. The researchers had never seen a case that severe in someone younger than 46 years old.
Can CTE Be Treated?
Unfortunately, there is currently no treatment for CTE, which is compounded by the fact that there's no way to test for it in living patients. The Mayo Clinic recommends prevention of head injury — especially repeated head injury — as the best preventative measure.