Alzheimer’s disease is a neurodegenerative disease frequently affecting elderly subjects. Increase of average lifespan enabled by the improvement of living standard conditions is one of the reasons accounting for the increase in the number of people affected by this pathology.
Memory loss is often the first symptom people complain about, which allows diagnosis orientation. Then, executive function disorders occur, space-time orientation disorders, and gradually language disorders settle in (aphasia), writing disorders (dysorthography), movement disorders (apraxia), behaviour and mood disorders (anxiety, depression, irritability), and sleep disorders with insomnia.
Neuron degeneration occurring in Alzheimer’s disease is the result of the simultaneous progression of two types of lesions : on the one hand the abnormal accumulation outside nerve cells of a protein called ß-amyloid peptide (or A-beta peptide or Aβ peptide) leading to the formation of “amyloid plaques” also known as “senile plaques“, and on the other hand, abnormal accumulation of TAU protein in neurons leading to their degeneration.
Now it is estimated that 860 000 people suffer from Alzheimer type dementia in France, and 35 million sick people throughout the world. While its onset before 65 is rare (0,5 %), its frequency is 2 to 4% once this age is passed. Then, it increases proportionally with age, to exceed 15 % at 80. More and more women suffer from this disease (1 in 4 women and 1 in 5 men after 85). In 2020, the number of patients is estimated at two millions only for the French population.
Institut du Cerveau – ICM RESPONSES
TOPICS AND RESEARCH TEAMS
- Identify risk factors to better diagnose or even prevent the onset of the disease with Bruno Dubois’s team.
- Understand the mechanisms at stake in the spread of both Alzheimer’s and prion diseases, and develop experimental models to diagnose the disease and test new therapeutic approaches with Marie-Claude Potier and Stéphane Haïk’s team.
- Study the role of lipids in Alzheimer’s disease in order to identify therapeutic targets with Marie-Claude Potier and Stéphane Haïk’s team.
- Study the role of the immune system to find ways to fight the disease with Cécile Delarasse in Bertrand Fontaine and Sophie Nicole’s team.
- Test new drugs in national and international multicentric therapeutic trials, with Bruno Dubois’s team.
Lesions of Alzheimer’s disease 20 years before its apparition
Several recent studies confirm that the presence of amyloid plaques allows to diagnose people who suffer from Alzheimer’s disease, or even to predict who will develop the disease. In an international study, Harald Hampel – also holder of the AXA/Sorbonne Université chair on Alzheimer’s disease – and his collaborators have identified a silent stage of the disease of approximately ten years, where no clinical signs occur, but where biological markers are visible, indicating that it is possible to detect Alzheimer’s disease at an earlier stage. Identify diagnostic or even predictive markers of Alzheimer’s disease, particularly 20 to 30 years before dementia symptoms, is today a major challenge regarding this pathology.
Diagnose Alzheimer’s disease with a blood test ?
The identification of blood markers to diagnose Alzheimer’s disease at an early stage and predict its evolution is a major challenge. A study of Marie-Claude Potier’s team shows for the first time that blood cells from patients with Alzheimer’s disease develop specific morphological alterations. This discovery raises the hope of being able to diagnose the disease through a simple blood test.
Dementia or Alzheimer’s : a simple test could differentiate them
Patients with fronto-temporal dementia need specific and appropriate medical care. However, this disease is still too often confused with Alzheimer’s disease. Clinicians and researchers from the Institut du Cerveau – ICM and from the Memory and Alzheimer’s Disease Institute (IM2A), in collaboration with an international team, have just demonstrated that simple tests evaluating empathy could guide the diagnosis.
Better understand the causes of the disease
The INSIGHT study, conducted in partnership with the IHU, the Memory Institute (IM2A), the Plan-Alzheimer Foundation, AMIVID and Pfizer and coordinated by Professor Dubois, is a groundbreaking study on Alzheimer’s disease. It is indeed one of the first in the world to follow more than 320 at risk healthy subjects in order to understand how and why Alzheimer’s disease occurs in some people and not in others and identify the factors of the onset of Alzheimer’s disease. This study is carrying great expectations in terms of understanding the disease.
A first therapeutic trial to prevent the onset of the disease
Bruno Dubois and Isabelle Le Ber, in collaboration with Pr Hannequin from the Rouen University Hospital, are conducting an international multicentric study aiming at testing the efficiency of a neuro-protective drug in rare genetic forms of Alzheimer’s disease. Its originality is to offer the treatment to subjects without symptoms too, but at risk of developing the disease, being healthy carriers of a mutation responsible for the disease. It is the first neuro-preventive therapeutic trial ever used in human.
Effect of a drug on the progression of Alzheimer’s disease at an early stage
Solane protocol, coordinated by Bruno Dubois, aims to test the effect of solazenumab, a drug which could decrease or slow down the formation of amyloid plaques which are thought to be one of the causes of Alzheimer’s disease symptoms. The objective of this study is to test this drug efficiency on the progression of the disease at an early stage : does it allow to slow down the mental and functional decline associated with the disease ?
Immune system early protective role
A study conducted in collaboration with the Sainte-Anne Hospital Center, the CEA, the Saint-Antoine research center and Roche, and co-ordinated by professor Marie Sarazin shows, through a brain imaging innovative technique, the beneficial and protective role of the immune system during early stages of Alzheimer’s disease. This study highlights the importance of diagnosing the disease early and opens new therapeutic prospects to slow down or even prevent its development.
A new molecule
In collaboration with MEDDAY, a start-up founded by Guillaume Brion and Frédéric Sedel, a research project was started to test the therapeutic potential of a new molecule, MD1105, against Alzheimer’s disease.