Spanish researchers make progress towards early detection of Alzheimer's Disease

A carer holds an elderly dementia sufferer's hands.
A carer holds an elderly dementia sufferer's hands. / R.C.
  • The discovery of cerebral alterations in people who have no symptoms but carry a high-risk genetic load will lead to therapies which may prevent this type of dementia

Spanish researchers from the Pascual Maragall Foundation have made a pioneering discovery which will enable some types of Alzheimer's Disease to be detected early in people who are still healthy and showing no sign of the illness. About 800,000 people in Spain currently have Alzheimer's, and that number is expected to triple in the next 30 years and reach epidemic proportions.

The experts, who received financial support from La Caixa Foundation, have just published the results of the world's largest neuroimaging study - magnetic resonance scans of the brain - carried out on people who are healthy but who carry the gene which gives the highest risk of suffering Alzheimer's, the APOE-E4.

The study, which will be published in 'Alzheimer's & Dementia: The Journal of the Alzheimer's Association', examined 533 people aged between 45 and 76, of whom 272 were carriers of the APOE-E4 gene.

This was part of a wider and more global study called Estudio Alfa, which with 2,743 volunteers aged between 45 and 75, most with parents with Alzheimer's, looked at depth into different aspects of the illness.

The research was led by doctors José Luis Molinuevo and Juan Domingo Gisbert and, by comparing the results of the resonance scans, they were able to identify significant neuroanatomical differences - alterations of the cerebral structure - which were proportional to the genetic load associated with the participants' risk of Alzheimer. These neuroanatomical differences in the APOE-E4 load are more evident after the age of 60, which is the same age that other cerebral alterations associated with the illness also occur.

The Spanish experts believe this discovery is a step towards preventing the illness, because these alterations can be taken into account in clinical tests designed to prevent Alzheimer's long before the clinical symptoms appear.

“Knowing the role and the structural changes caused by the different risk factors will enable us to design better clinical tests,” explains José Luis Molinuevo.

“Research is the only way to advance towards early detection and prevention of this illness, which could become a pandemic during this century,” says Ángel Font, director of Research and Strategy at La Caixa Foundation.

Early detection and prevention are fundamental tools in the fight against Alzheimer's because this neurodegenerative illness, which affects about ten per cent of over-65s and represents between 60 and 80 per cent of dementias diagnosed in the world, still has no cure.

The fact that some of the markers can anticipate that a healthy person has a high risk of developing the illness is key to early intervention, because the principal symptoms -severe loss of memory, disorientation or problems with speech and writing - do not appear until years after the illness has started to develop.

The next step

The next step for the researchers will be to evaluate the impact of alterations in the biomarkers which are typical of Alzheimer's, such as the presence of Amyloid beta and Tau proteins in the neuroatonomical alterations described in this study.

In 2012 the Barcelonaßeta Brain Research Center began to recruit volunteers for the Estudio Alfa, one of the most technologically advanced research platforms, with the highest number of healthy participants in the world, which is dedicated to early detection and prevention of Alzheimer's in Spain.

Depending on their characteristics, the Estudio Alfa volunteers took part in different sub-studies, focusing on different aspects of prevention. These involved monitoring and certain cognition, epidemiology and medical tests. A subgroup of 400 participants were also given two magnetic resonance scans, an Amyloid PET scan, a glucose PET scan and a lumbar puncture; these tests will be repeated every three years for decades, to try to gain an understanding of the natural history of the illness and identify the risk factors and biological indicators which could occur in its development.