Today, neurologists have no therapeutic solution for the million French people affected by Alzheimer’s. But research progress gives hope.
Each year, 200,000 new people are affected by Alzheimer’s disease, making it the most common neurodegenerative disease in our country. It is also one of the scariest, due to the lack of treatment. Research is making great strides, however, underlines the CNRS in his dossier “Alzheimer’s: where is the research? “.
In fact, over the past two decades, researchers have succeeded in unraveling several mysteries surrounding this dementia. One of the greatest advances is certainly in the field of diagnostics. 15 years ago, neurologists could not say that their patients indeed suffered from this disease. Its development was unrecognized. Now, specialists know that it starts in the hippocampus before spreading to the rest of the brain. They can also be based on 3 well-defined clinical criteria: neuronal loss, accumulation of amyloid plaques and aggregation of tau proteins.
Developed biological tests
Thanks to their identification, it was then possible to develop biological tests capable of helping doctors in their diagnosis. Until now, specialists only had MRI scans and cognitive tests at their disposal. “We gave results with a wet finger. The objective was above all to eliminate other pathologies, and then we estimated a probability that it was Alzheimer’s disease, ”says Bruno Dubois, head of the Center for Cognitive and Behavioral Diseases at the Pitié-Salpêtrière hospital.
Today, with a sample of cerebrospinal fluid, it is possible to detect the presence of the tau protein. A large amount of this biomarker is a sign that Alzheimer’s disease is developing. The latter can be detected at every stage of the pathology, even when it is silent. An asset that can be detrimental because there is no treatment. “Biomarkers must remain a diagnostic complement, when there is a doubt, or in young people for example”, estimates the neurologist.
Research has also led to a better understanding of risk factors. Genetic forms, for example, have been discovered. “There are very rare mutations that cause the disease, but these patients only represent 0.3% of Alzheimer’s forms. These mutations are carried by genes involved in the genesis of amyloid peptides ”, indicates Luc Buée, research director at the Jean-Pierre-Aubert research center (Lille).
Poor lifestyle is also involved. But age seems to be the most important precursor. “Over time, proteins will aggregate in the brain. And the longer life lasts, the more the probability of protein accumulation increases, ”explains Ronald Melki, research director at the Paris-Saclay Institute of Neurosciences. To counteract this natural phenomenon, you have to “make your brain work, with reading or discussions.” To this must be added regular and constant physical exercise, which will oxygenate the brain and provide it with nutrients, ”advises the specialist.
Long-term hope
Better understanding the risk factors and identifying biomarkers of the disease have also opened up several therapeutic avenues. Immunotherapy is one of them. For the past fifteen years, researchers have been trying to boost the immune system so that they destroy amyloid plaques or the aggregation of tau proteins. Other research teams then embarked on the development of preventive strategies capable of preventing the formation of lesions.
Unfortunately, clinical trials are proving disappointing. But researchers are not giving up. “Only this understanding of the mechanisms involved, and their dysfunctions, will make it possible to identify pharmacological avenues aimed at blocking the development of the pathology or, at least, interfering in its progression”, estimates Frédéric Checler, research director at the Institute of Molecular and Cellular Pharmacology (Nice). “We’ve been trying to find a good combination for almost 20 years. In 10 or 15 years, we will surely have many more solutions ”, indicates optimist Ronald Melki.
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