Researchers from the Polytechnic University of Madrid participate in an international project identified a new biomarker for Alzheimer’s disease, using magnetic resonance imaging (MRI).
Alzheimer’s disease (AD), which affects more than 800,000 people only in Spain, according to the Spanish Society of Neurology, is the predominant form of dementia in the elderly population. One of the main problems for treatment and prevention of this disease is the difficulty of detecting it early. In fact, it is estimated that between 30 and 40% of those affected are undiagnosed.
Researchers from the Polytechnic University of Madrid (UPM) have participated in an international study that has identified a new biomarker to detect the disease early using MRI.
“It is increasingly evident that when a patient is diagnosed with Alzheimer’s disease, atrophy is already well established in the brain. In affected individuals, entorhinal volumes have already been reduced by 20-30% and hippocampal volumes by 15-25%,” explains Consuelo Gonzalo, of the Center for Biomedical Technology of the UPM and one of the authors of the study.
However, estimates on the progression of atrophy (between 0.8 and 2% per year) suggest that this process must have been active over for several years before diagnosis or even the presence of symptoms. So being able to detect these small initial anomalies is vital for an early diagnosis of the disease.
According to different studies it is known that, although it is difficult to identify Alzheimer’s in the initial stages, neurofibrillary tangles and beta-amyloid plaque deposits (Aβ) have been detected. The main result of these alterations is the destruction of the synapses, followed by the degeneration of the axons and, ultimately, the atrophy of the dendritic tree and the pericardium, which leads to atrophy in specific regions of the brain, such as the hippocampus.
The process of degeneration can be visualized through different medical images and has proved to be a valuable biomarker of the stage and the potential aggressiveness of the neurodegenerative aspect of Alzheimer’s disease.
“The great advances in neuroimaging have provided opportunities to study diseases related to neurology. Positron emission tomography (PET) and magnetic resonance imaging (MRI) are widely used in related studies given their wide availability, their non-invasive nature and the relative absence of discomfort for the patient,” explains Consuelo Gonzalo.
Closer to early diagnosis
However, the changes in the initial stage are subtle and it is difficult to distinguish the patterns through conventional radiological evaluation. Therefore, it is still difficult to establish reliable biomarkers for the diagnosis and monitoring of the progression of the disease, especially in the early stages. This has led to the development of numerous automatic methods for the evaluation of brain atrophy, such as the UPM study.
The experimental results obtained have shown a significant improvement in the classification of Alzheimer’s disease against cognitive impairment compared to other approaches found in the literature.
“Although, given the differences in age, sex, deficiency or image quality among the study populations, it is impossible to make a direct comparison, in general, we can say that the results obtained are comparable or better than those of similar textural methods,” he explains.
“The data obtained with the proposed method suggest the extension of the study to other cases, such as the discrimination between normal and mild cognitive disorder or to predict the evolution of mild cognitive disorder to Alzheimer’s disease, as well as the expansion and refinement of it shows through its extension to other databases,” concludes the researcher.
As a proposal for the future, the authors have in mind the improvement of the discrimination capacity of the textural characteristic presented in this work, applying it only to specific areas of the brain.