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Sports concussion has long term impact on the brain, Deakin University research finds

16 December 2013

In an Australian first, Deakin University research has found that sports concussions do have a long term, negative, impact on the brain.

Dr Alan Pearce, a neuroscientist with Deakin University’s School of Psychology, has investigated the long-term impact sports concussion had on the brain function of 40 retired Australian rules football players. The results showed the former players experienced a reduction in fine motor control and abnormal changes in brain function when compared with healthy people of the same age who had never played contact sport.

Concussions sustained while playing sport are becoming a major public health concern in Australia. While studies have been conducted on football players in the United States, this study is the first to look at Australian rules footballers.

“Sports concussion is a form of mild traumatic injury, where a blow to the head affecting brain function that can result in impaired memory, reflexes and muscle coordination,” Dr Pearce explained.

“While incidents seem to be on the rise, with an estimated six to seven injuries per team, per season, at all levels of Australian football each year, we have previously been unaware of the long term effects of repeated sports concussion.

“With the results of this study now in, it is time that football clubs at the elite and amateur level put in place more robust policies to care for concussed players that include mandatory periods of rest following a concussion.”

For the study, Dr Pearce measured the brain activity, mental ability and fine movement dexterity of 20 retired elite (average age 49.7 years) and 20 retired amateur (average age 48.4 years) footballers and compared the results to 20 age-matched healthy people who had never played contact sport. The elite and amateur footballers had averaged 3.8 and 2.4 serious concussions (defined as being unconsciousness followed by disorientation and confusion) respectively in the 20 years prior.

All study participants undertook tests for fine movement control and reaction time, short-term memory and learning, and neurological testing using magnetic brain stimulation.

While the tests did not uncover differences in memory and association learning, both the elite and amateur former footballers performed markedly worse in the fine movement control and reaction time tests compared to the healthy study participants.

The brain stimulation tests also revealed significant differences in the brain activity of the football players and healthy controls. The football players showed abnormal hyperactivity or loss in excitability in their brain pathways. The same levels of altered brain function were found for elite and amateur players, indicating that the standard of play made no difference to the impact concussion had on the brain.

“It is now clear that multiple sports concussions have serious long term impact on the brain,” Dr Pearce said.

“And, in a result that I found surprising, the level of impact is the same regardless of whether the concussions are experienced by elite or amateur players.

“The changes in brain function could see the former players experience difficulties with everyday activities.

“With the reduction in fine movement control they could have difficulty with anything that required the use of the thumb and first finger such as putting in keys into doors. While the excitability of the brain waves reflects long term abnormal changes in brain activity that underlie with the movement behaviour changes observed.

Dr Pearce said it was time for all football clubs to develop a policy of a mandatory rest following a serious concussion where a player is knocked unconscious and/or has to be carried from the field.

“Clubs also need to engage the services of a medically qualified people to assess and monitor concussed players by the field of play and then for the period of time during recovery, such as one to four weeks, or longer, depending on the severity of the concussion.”

Dr Pearce also put out a call to retired players not to suffer in silence.

“If a retired player, regardless of standard of football they played, is unsure of their brain health having been concussed, they should seek help to have their brain function assessed; don't sit in silence. It is only through assessment that the true state of their brain’s function can be revealed and, if necessary, appropriate rehabilitation can be put in place to improve brain health.”

Notes about the tests conducted for the study:
• Fine movement control was assessed by placing three small pins into one hole. The time taken to complete 30 holes was measured.
• Reaction time was measured by participants responding to a coloured light stimulus on a tablet computer. Both reaction (stimulus presentation to first response) and movement (time to touch the coloured light on the computer screen) was measured.
• Short-term memory and learning, was evaluated via computer. Memory was assessed by remembering where hidden tokens were within coloured boxes, whilst association learning was assessed by participants learning where patterns were hidden behind white boxes
• Brain stimulation was assessed by transcranial magnetic stimulation. Brief electromagnetic pulses were delivered above the participant’s head whilst electrodes measured the responses in the hand. The brain wave responses provided measures of activity in the area of the brain that controls movement

News facts
  • A study of 40 retired Australian rules football players who had experienced a concussion while playing finds long-term impact on brain function
  • Results showed former players experienced a reduction in fine motor control and abnormal changes in brain function when compared with healthy people of the same age who had never played contact sport
  • Researcher says it's time for all football clubs put in place a policy of mandatory rest following a serious concussion and players should not suffer in silence

Media contact

Mandi O'Garretty
Deakin Media Relations
03 5227 2776; 0418 361 890
mandi.ogarretty@deakin.edu.au

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16th December 2013