5 minute scan gives warning of Alzheimer's
by Fiona Macrae for The Daily Mail:
A five-minute brain scan could give healthy people early warning of dementia, scientists believe.
They found that by measuring blood flow in the brain, it is possible to distinguish healthy people whose memory will decline from those who stay mentally sharp.
In other words, tell-tale signs are present in the brain long before the memory fades.
Those given warning of the disease could take preventative measures such as changing their diet and taking more exercise.
Quicker detection would allow earlier treatment and, with the help of new drugs, some who test positive might never develop the disease.
Alzheimer’s and other forms of dementia affect some 800,000 Britons and the number is predicted to double in a generation as the population ages. David Cameron has described dementia as ‘the key health challenge of this generation’.
The Swiss researchers used a version of the MRI scans carried out regularly in hospitals to measure blood flow in the brain of more than 200 elderly men and women.
Some were healthy, while others had mild cognitive impairment (MCI) – the slight memory lapses that can develop into full-blown dementia. Generally, up to 15 per cent of people with MCI develop Alzheimer’s within the next year.
The men and women were also put through a battery of mental tests, including memory. Not surprisingly, the healthy subjects did better than those with MCI.
But when the tests were repeated 18 months later, half of the healthy men and women found them harder.
And, importantly, their brain scans, from the start of the study, were like those of the people who already had MCI.
It is thought that other parts of the brain had initially compensated for damaged areas – masking the problem at the start of the study.
But, by 18 months on, the symptoms were showing. Their brain scans showed that less blood was getting to an area in the middle of the brain called the posterior cingulate cortex, which is active when our mind is at rest.
Previous research has shown this region to be less active chemically in people with Alzheimer’s disease.
Researcher Sven Haller, of the University of Geneva, whose study is published in the journal Radiology, said it isn’t clear whether lack of blood to the brain causes memory loss, or whether blood stops flowing because the brain is damaged.
ut, in either case, he thinks the scan, which takes as little as five minutes, could provide vital early warning of memory problems. Being able to predict who will become ill could speed the search for new drugs that can delay or even prevent Alzheimer’s.
Existing medicines are of limited use and several promising pills and potions have failed to live up to hopes.
However, many believe this is because they are being tested too late in the disease – and may work if given in the very early stages.
Dr Simon Ridley, of charity Alzheimer’s Research UK, said: ‘There is a growing amount of research into using various brain-scanning techniques to accurately detect changes to the brain before dementia symptoms show.
‘This study was very small and the volunteers were not diagnosed with dementia so it is not possible to tell at this stage whether this technique can be used to identify those at risk of the condition.
‘Larger and longer-term studies are needed.
‘Current methods can only accurately diagnose the condition long after the damage to the brain has started.
‘There are no drugs available at the moment that can stop or slow dementia.
‘Detecting changes in the brain as early as possible will allow people to enter clinical trials for much-needed new treatments before their symptoms have progressed too far and when they’re most likely to benefit.’
Source: http://dailym.ai/1t18kRu