A LEADING pathologist is calling for more brains to be dissected after people die to help explain the invisible injuries afflicting sports stars and war veterans.

Dr William Stewart, a consultant neuropathologist at the Queen Elizabeth University Hospital in Glasgow, said awareness was gradually growing that bangs to the head from accidents, explosions and sport could cause silent "smouldering" damage.

However, he said, more needed to be understood about what happened in the brain and the only way they could even diagnose patients with confidence was by "post mortem".

He spoke out as American researchers announced they had found a "distinctive pattern" in the brains of eight military personnel hurt in massive explosions.

Dr Stewart said: "The number of brains examined for aspects of brain injury is remarkably few despite the fact in society this is a big problem."

Originally associated with boxers - such as Muhammad Ali who suffered Parkinson's disease attributed to his career - concern is now growing that other sportsmen and women may be at risk of damage to the brain which does not show up on scans.

Dr Stewart said Glasgow had an archive of around 1500 samples from people who had died with a brain injury, including at least a dozen from sports players.

"Many of the pathology processes that we see in survivors of brain injury are the same as what we see in people with Alzheimer's disease," he said.

However, he said, while some 2bn dollars had been spent on the problem including laboratory research and developing new body armour, very few brains had been examined.

Dr Stewart said: "It is all very well investing millions in pre-clinical research and developing new body armour, but some of that money has to go into trying to understand what is happening in the brains of these people."

Assumptions, he said, had been based on animal models. He continued: "The reason I am such an advocate for human pathology is there is not really a suitable model for a human brain. Clearly we do a lot of things that mice do not, like play football."

Patients affected do die prematurely, he said, but "there is no effort being made to try and direct the (brain) material to the appropriate places to be looked at."

He hopes better understanding of the problem could help dementia research as well as inform the way injuries are dealt with and ensure patients are diagnosed correctly.

Dr Stewart, who commented about the need for research alongside the American findings in the journal Lancet Neurology, said: "Often the point where the dementia or the brain injury is diagnosed is actually several years after the first signs and symptoms were there. That is the difficult thing: Those years where there are the first signs of behaviour change, the husband has been more aggressive or businesses fail for otherwise successful men or women.

"Once the diagnosis is made you can wind back the clock and you can begin to understand why the personality changed, why things began to go wrong for them."

Frank Kopel, a footballer who spent 10 years with Dundee United, was originally told he had vascular dementia at the age of 59. However, his wife Amanda felt the diagnosis did not quite fit. She wrote to Dr Stewart after seeing his name in a newspaper and discussed the symptoms. She said: "Dr Stewart listened. At no point did he ever hit back and say 'it is your imagination.'"

After viewing her husband's scans Dr Stewart concluded it was more likely he was suffering from chronic traumatic encephalopathy (CTE) a degenerative disease found in people who have suffered repeated blows to the head.

Mrs Kopel recalls her husband heading balls in matches, lying on the ground for minutes after collisions before returning to the game and even playing "header" tennis in training.

She was asked if should would donate his brain for research by American scientists on the way to Mr Kopel's funeral. She did consider agreeing, but ultimately said: "I honestly feel Frank has suffered enough."

However, she backed Dr Stewart's call for more research. She said: "They have to recognise the dangers of this for young children."