Head injuries in sport may lead to dementia

A study on war veteran by researchers from the San Francisco Veterans Association medical centre, found that former soldiers diagnosed with a brain injury, anything from a concussion to a severe head wound, were more than twice as likely to develop dementia compared to those with no injury.

For the study, presented at an international Alzheimer’s conference in Paris, the researchers reviewed the medical records of 281,540 military personnel age 55 and older and found that the risk of dementia was 15.3 per cent in those who had traumatic brain injuries (TBI) compared to 6.8 per cent for veterans without TBI.

The results were even more striking in another study of retired American football players: 35 per cent of the former National Football League players had signs of dementia, compared to a 13 per cent Alzheimer’s rate in the general population, the MSNBC reported. The NFL player study was a follow-up of earlier study that included a survey of nearly 4,000 retired players in 2001. In 2008, new surveys were sent to the 905 players who were over 50 years old.

Of those who responded to the second survey, 513 had wives who could complete a section of questions addressing the players’ memory and cognition.

“We were surprised that 35 per cent of (the players) appeared to have significant cognitive problems,” said study author Dr Christopher Randolph of Loyola University
Medical Center in Chicago.

The two new studies add to rapidly accumulating evidence showing that head injuries, even concussions, can lead to severe consequences many years afterwards, said Dr Gary Small of the University of California and the author of “The Alzheimer’s Prevention Program”.

Some earlier researches found a two-fold increased risk of Alzheimer’s associated with head injuries that caused a loss of consciousness lasting an hour or more, Small said. And that risk jumped to 10-fold when people also had a genetic mutation called APOE-e4.

A study that compared soccer players to swimmers found that soccer players performed less well on cognitive tests, Small added.

Scientists believe that each hit to the head, even concussions, causes stretching of the
brain’s communication cables, known as axons. When the axons stretch, their inner structure is damaged.

Studies have shown that damaged axons can spew out proteins that lead to plaques and tangles in the brain which are known to cause dementia and Alzheimer’s disease.
Studies was conducted at the University of Pennsylvania.