Brain scan that could reveal first signs of Alzheimer’s

SCIENTISTS believe they have found a way to detect the first stages of Alzheimer’s.

It is hoped the breakthrough could lead to an accurate diagnostic test for the disease and ultimately a treatment.

Using a type of brain scanner, researchers were able to detect the build-up of ‘tangles’ of proteins that are thought to cause Alzheimer’s.

It is the first time the development of the two key proteins linked to the disease have been seen in living patients.

Previously the proteins have only be studied during postmortems. There is currently no diagnostic test for Alzheimer’s short of memory and cognitive skill tests.

Dr William Jagust, professor of neuroscience at Berkeley University in California, said the scans showed the build-up of two kinds of proteins, amyloid and tau protein, which have been linked to getting Alzheimer’s. He said: ‘Our study is the first to show the staging in people who are not only alive, but who have no signs of cognitive impairment.’

The expert added: ‘We can now very reliably and with a great degree of accuracy say that there are changes in a person’s brain that are very highly predictive that a person’s going to get Alzheimer’s.’

To test for Alzheimer’s, Dr Jagust and his colleagues carried out tests on 53 adults. Five were young adults aged 20 to 26; 33 were cognitively healthy adults aged 64 to 90; and 15 were patients aged 53 to 77 who had been diagnosed with probable Alzheimer’s dementia.

The researchers found that all ageing brains – in healthy patients and those with Alzheimer’s – had more ‘tangles’ of tau protein in an area called the medial temporal lobe, associated with memory. The subjects were given memory tests.

Researchers found that the people with higher levels of tau had worse memories. It is now thought it is the build-up of tau which leads to people’s memories worsening as they age. But having high levels of tau protein alone was not linked to the severe dementia seen in Alzheimer’s. At the same time, people with higher levels of amyloid alone did not get the disease.

But when the tau and amyloid were linked together, the serious declines in brain function seen in Alzheimer’s were found to be triggered, the researchers said.

It is not yet known whether tau leads to amyloid build up, or the other way round.

Dr Jagust said: ‘Amyloid may somehow facilitate the spread of tau, or tau may initiate the deposition of amyloid. We don’t know. All I can say is that when amyloid starts to show up, we start to see tau in other parts of the brain, and that is when real problems begin. We think that may be the beginning of symptomatic Alzheimer’s disease.’