The condition known as chronic traumatic encephalopathy (CTE) was formerly believed to exist primarily among boxers, and was referred to as dementia pugilistica. It is a progressive degenerative disease which afflicts the brain of people who have suffered repeated concussions and traumatic brain injuries, such as athletes who take part in contact sports, members of the military and others. The term encephalopathyderives from Ancient Greek en- “in,” kephale “head,” and patheia “suffering.” Chronic traumatic encephalopathy is a condition of brain damage which persists over a period of years or decades and which is the result of traumatic impacts to the cranium.
The brain of an individual who suffers from chronic traumatic encephalopathy gradually deteriorates and will over time end up losing mass. Certain areas of the brain are particularly liable to atrophy, though other areas are prone to becoming enlarged. Another aspect of CTE is that some areas of the brain experience an accumulation of tau protein, a substance which serves to stabilize cellular structure in the neurons but which may become defective and subsequently may cause major interference with the function of the neurons.
The symptoms of CTE can be debilitating and may have life-changing effects for both the individual and for his or her family. Some of the most common include loss of memory, difficulty controlling impulsive or erratic behavior, impaired judgment, behavioral disturbances including aggression and depression, difficult with balance, and a gradual onset of dementia. An individual with CTE may mistakenly ascribe the symptoms to the normal process of aging, or might receive a wrong diagnosis due to the fact that many of the symptoms are similar to other conditions such as Alzheimer’s or Parkinson’s disease. CTE has been diagnosed in several notable cases which received widespread media attention, including the suicide deaths of NFL player Junior Seau, and professional wrestler Chris Benoit who committed suicide after murdering his wife and son.
Reference: http://www.protectthebrain.org/Brain-Injury-Research/What-is-CTE-.aspx