An early diagnosis would give people the chance to try to slow the development of incurable dementia, said the researchers at the Technical University of Darmstadt.
Until now diagnosis has only been possible using radiological techniques such as computer or magnetic resonance tomography – or memory tests, the scientists said in a statement on Tuesday. But these do not allow for an early diagnosis.
But now chemists and pathologists at the university are developing a new method – having realised that tests of the nasal mucous membrane can show whether the damaging tau protein, which kill brain cells and can lead to dementia, are being deposited in the brain.
“Until now it was only known that these damaging deposits were not only detectable in the brain but also in the nerve cells of the eyes,” said Prof. Boris Schmidt of the Clemens-Schmidt. “Thus a diagnosis via retina scan was favoured. A fluorescent dye was needed to make the deposits in the eye visible to the examining doctor.”
But he and colleagues examining that dye realised that it could also be used to show the same deposits in the nose – and that this is a more sensitive indicator of what is happening in the brain.
“The more tau deposits we found in the noses of patients, the worse the brain structure was hit – such a connection has until now not been found with the eye deposits.”
Examining a patient's nose is also less difficult and uncomfortable than putting dye in their eyes – Schmidt said he could imagine check-ups which would involve a nose spray or tablet to deliver the dye, and then the doctor simply looking with a light.
So far Schmidt and his colleagues have examined tissues from 100 dead Alzheimer's patients while the nose examinations are being carried out on patients at the Ludwig University in Munich.