Chronic traumatic encephalopathy (CTE) is a progressive brain disease linked to head trauma from direct blows, blasts and other types of traumatic brain injury. In the early 2000s American forensic pathologist Bennet Omalu, after doing an autopsy on a former football player, discovered that the neurological deterioration to the player’s brain was similar to that caused by Alzheimer’s disease. His findings showed that repeated blows to the head, which is common among athletes such as boxers and footballers, can lead to reduced brain activity and blood flow.
In CTE cases, brain tissue displays an abnormal buildup of tau, a protein that can negatively impact neuron pathways. Although they may not show up for years, typical CTE symptoms include problems with short-term memory, mood and fear, and behavioural disturbances such as depression, impulsivity, impaired judgement, aggressiveness and irritability, all of which can escalate to suicidal behaviour and lead to dementia. A small subset may develop chronic traumatic encephalomyelopathy, a progressive motor neurone disease that’s similar to amyotrophic lateral sclerosis, characterised by profound weakness, atrophy and spasticity.