Scans ‘could hasten Alzheimer’s diagnoses’

‘They can help doctors by indicating or ruling out Alzheimer’s as the possible cause of symptoms’

ROUTINE brain scanning could improve dementia diagnoses for two thirds of patients, ending years of misdiagnoses, a study has found.

Currently, the main way to determine whether Alzheimer’s is present is to look at the brain of a patient after death. For patients who are still alive, doctors use special cognitive tests that monitor memory and everyday skills such as washing and dressing, but the results can often be misleading or inaccurate.

However, findings presented at the Alzheimer’s Association International Conference in London yesterday show that Positron Emission Tomography (PET) scans altered the diagnoses for more than two thirds of people. Those with early stage Alzheimer’s can wait up to four years to receive a correct diagnosis because PET scans, which cost up to £3,000 a time, are rarely carried out on the NHS.

The scans show the build-up of sticky amyloid plaques in the brain – which prevent neurons communicating and eventually kill areas, wiping out memories – and can help with a definitive diagnosis.

As well as detecting problems early, when drugs or lifestyle changes could help, the scans could also reassure people with mild memory problems that they do not have the disease.

Dr David Reynolds, the chief scientific officer at Alzheimer’s Research UK, said: “Diagnosing dementia is a complex challenge. This research highlights the value that amyloid brain scans can bring in helping doctors make a more informed diagnosis, either by indicating or ruling out Alzheimer’s as the possible cause of dementia symptoms.”

PET scans pick up how good parts of the brain are at sucking up glucose, which is injected into the body bound to a radioactive tracer, which can be seen on screen. Parts of the brain that are not functioning will not light up.

The study by the Karolinska Institute in Sweden, involving 135 people who had been referred for memory problems, found 68 per cent had a change in diagnosis after the scans.

A separate study led by GE Healthcare in the UK analysed data from four previous studies, combining data from 1,106 people, and found that use of PET scans during the process of diagnosing dementia led to a change of diagnosis in 20 per cent of people.