The concussed brain

Beware brain injuries in sport

After the Lions XII clinched their first Malaysia FA Cup on May 23, coach Fandi Ahmad said he hoped the win would inspire more children in Singapore to take up soccer in a big way.

Not to be a party pooper, but any push to encourage soccer or indeed any other contact sport, be it rugby, boxing, hockey, cheerleading or even lacrosse, should come with a loud warning about concussions.

There is not enough awareness among players, coaches, sports administrators, teachers and the general public that anyone engaged in contact sports - especially schoolchildren - must be prevented from returning to play if they suffer a concussion during a game or practice.

There are many misconceptions about concussions. First, of course, a direct blow to the head can cause a concussion but it can also result from a blow to the body where its impact is transmitted to the brain.


ST ILLUSTRATION: MIEL

Second, unlike what is commonly assumed, a concussion does not always lead to brief loss of consciousness and/or memory. In its immediate aftermath, a concussion may lead to confusion, dizziness, slurred speech, incoordination or disorientation.

Heading a soccer ball registers a force of 15 to 30 Gs on the head, where one G is equal to the force of gravity at the earth's surface.

Players of both English and American football are now known to be susceptible to brain injury caused by repeated concussions.

Public awareness in the United States led to all 50 states and the District of Columbia passing laws by 2014 to address youth sports concussion. These laws mandate that school and college athletes may not return to play if they are suspected of having been concussed on field, and they must be subjected to detailed cognitive and medical tests afterwards.

There is now irrefutable evidence that repeated concussions cause brain tissue to degenerate.

First shown in the brains of boxers, the degeneration has also been seen in autopsies of the brains of athletes involved in American football, soccer, ice hockey and professional wrestling.

Normal brains have only four ventricles, which are interconnected cavities in the brain filled with cerebrospinal fluid. But autopsies have found a fifth ventricle in the brains of former athletes who died of dementia.

In repeatedly concussed brains, some or all of the four ventricles may also become flabby and enlarged. Moreover, pores may develop in the back of the brain while specific parts of the brain may thin out, so that the brain shrinks as a whole.

Under the microscope, slices of such brains show several dark squiggles that look like commas. These are tangles made of a protein called tau, also found in the brain of people with Alzheimer's disease. However, the tau tangles are found in more superficial layers of the concussed brain, compared to those in the Alzheimer's brain.

These tau tangles choke and kill brain cells. If the brain cells involved are in the frontal lobe, behind the forehead, the results are disastrous since that lobe is involved in judgment, intellect and insight. This condition, called chronic traumatic encephalopathy (CTE), was first recognised in 1928 in retired boxers, who were dubbed "punch drunk".

How can repeated concussions come to all this?

 

Mild trauma to the brain probably causes nerves and blood vessels to be sheared, causing diffuse leakages of fluids from the nerves. It is such leakages, when repeated and diffuse, that lead to the formation of tau, that kills brain cells.

Though the brains of soccer players have not been studied at autopsy as extensively as those of American football players, epidemiological studies suggest that similar changes are likely. When soccer players were compared to swimmers and track athletes in a 1999 Dutch study, they performed significantly worse on cognitive testing for their ability to plan and remember things.

A 1991 study in Norway of former professional soccer players aged 40 to 70 found that they had higher rates of abnormal electrical activity in the brain and more brain shrinkage as well.

It was estimated that such players had headed the soccer ball more than 2,000 times in their careers. This is significant as a 2003 study showed that heading a soccer ball registers a force of 15 to 30 Gs on the head, where one G is equal to the force of gravity at the earth's surface. It showed that heading a ball that had been kicked downfield or from a corner kick saw the most forceful impacts.

While American football sees more linear forces to the head as it involves a lot of head-butting, soccer sees more rotational shearing forces to the brain where heading the ball is concerned.

However, when players or coaches are told about the harm from repeated concussions, there is a lot of scepticism because the concussed athlete often appears fit to play soon after the knock on the head, even if he feels a bit "off". This is unlike a serious knee or shoulder injury, which results in the player being taken off at once to be checked and tested.

Not so with concussions. Doctors don't send the concussed athlete immediately for a brain scan. He just gets up and continues playing. But while a severe knee injury can end a soccer player's career, repeated concussions can have even more serious long-term consequences - a post-concussion syndrome - that can eventually be fatal if it ends up in CTE.

But up to 20 years ago, only a quarter of neurologists felt that post-concussion syndrome was real. Most felt that repeated concussions in sports were largely benign events.

Since 2005, however, a consensus has emerged among experts that the syndrome does exist. It may see the patient having frequent headaches. Also, his sleep may be disturbed, he may not be able to concentrate, is irritable and may be depressed.

These symptoms typically resolve within a week or two. But the younger the patient, the longer the symptoms persist, especially if he has had prior concussions. Girls tend to develop more symptoms and take longer to recover.

Many years later, however, CTE may develop, with the person having memory problems, depression, suicidal tendencies, aggressiveness, Parkinson's symptoms and, finally, dementia.

Can wearing helmets prevent all this? Research has shown that the modern helmet that is part of American football gear protects the skull but not the brain. So requiring helmets for, say, soccer may not help much either.

The best preventive measure is to mandate by law the removal of an athlete from play after a suspected concussion. As to when he may return to play, an invaluable guide is The Return To Play Protocol proposed in 2008 by the Third International Congress on Concussion in Sport.

We must also raise awareness among those involved in contact sports - players, parents, trainers and coaches - about the subtler signs and symptoms of concussions. It is high time that concussions be recognised for what they are, a public health risk.

  • This is the second of a six-part weekly series by Andy Ho on new science on the brain.

Next week: The Addicted Brain.

A version of this article appeared in the print edition of The Straits Times on July 25, 2015, with the headline 'Beware brain injuries in sport'. Print Edition | Subscribe