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Initial injury

Repetitive head trauma is likely the cause of CTE. Football players have been the focus of most CTE studies.

However, athletes participating in other sports, including soccer, ice hockey, rugby, boxing, wrestling, basketball, field hockey, cheerleading, volleyball and lacrosse, may experience repeated head impacts and also have high rates of concussion.

CTE has also been found in people who repeatedly bang their heads, people who have been physically abused, and those with epilepsy that has not been well-controlled. Blast injuries to military personnel also can result in CTE.

However, not all athletes and not everyone who experiences repeated concussions, including military personnel, go on to develop CTE. Some studies have shown no increased incidence of CTE in people exposed to repeated head injuries.

Effect of injury

CTE is thought to cause areas of the brain to waste away (atrophy). Injuries to the section of nerve cells that conduct electrical impulses affect communication between cells.

It's possible that people with CTE may show signs of another neurodegenerative disease, including Alzheimer's disease, amyotrophic lateral sclerosis (ALS) — also known as Lou Gehrig's disease — Parkinson's disease or frontotemporal lobar degeneration — also known as frontotemporal dementia.

April 20, 2016