Chronic Traumatic Encephalopathy (CTE)

CTE is a progressive form of neurodegeneration, clinically associated with memory disturbances, behavioral and personality change, Parkinsonism, and speech and gait abnormalities.

It is caused by repetitive, low-energy impact brain trauma as seen in sports-related environments such as football, rugby, boxing, soccer, ice hockey, baseball, cycling and skiing.

Clinical symptoms of CTE are only beginning to be understood. They include changes in mood (i.e. depression, suicidality, apathy, anxiety), cognition (i.e. memory loss, executive dysfunction), behavior (short fuse, aggression), and in some cases motor disturbance (i.e. difficulty with balance and gait).

Because of the lack of identified biomarkers, the diagnosis can only be made definitively postmortem.
CTE is a distinct clinical entity from Traumatic Brain Injury, which is the consequence of a single, focal impact upon the head with sudden acceleration/deceleration within the cranium (for example, explosion, or penetrating trauma).

However, both conditions are associated with oxidative stress, which causes secondary damage to neurons and prevents functional recovery.

At postmortem, the pathology is characterized by accumulation of amyloid and tau proteins in the brain.