For the second edition of World Lewy Body Disease (MCL) on January 28, 2025, why Doctor takes stock of this form of dementia which affects at least 150,000 French people.
- “Lewy’s body disease is a neuro-evolving disease that is much more frequent after 80 years,” said Professor Blanc.
- The diagnosis is based on the presence of cognitive disorders associated with one or two other symptoms among the following four: visual hallucinations; Paradoxical sleep behavioral disorders; cognitive fluctuations; A Parkinsonian syndrome.
- “We don’t know the causes of Lewy’s body disease. On the other hand, certain elements allow us to have an idea of risk factors ”, in particular stroke and the family history of MCL or Parkinson.
Little known, Lewy’s body (MCL) is the second most widespread neurocognitive pathology after Alzheimer’s disease. In France there would be at least 150,000 people affected but it is difficult to have exact figures because according to the Alzheimer’s research foundation, “” “2/3 of patients would not be diagnosed”. What is this disease? How is the diagnosis? What are the risk factors? Answers with Pr Fréderic Blanc, geriatrician and great specialist in MCL who returns to this disease in a video.
Lewy dementia: frequent neuro-evolutive disease after 80 years
“” “Lewy body disease is a neuro-evolving disease that is much more frequent after 80 yearsexplains Professor Blanc. It is a disease that first combines cognitive disorders. In general a slowdown, attentional difficulties and/or organizational difficulties.”But to say that there is MCL, it takes both cognitive disorders and one or two other symptoms among the following four:
-visual hallucinations;
-Ative -dormant behavioral disorders: “These are people who move in their bed, who have nightmares and who will live their dream when they should not”;
-cognitive and vigilance fluctuations, “that is to say moments when patients will be less property and other moments when they will be better”;
-A parkinsonian syndrome (physical slowdown, rigidity and often falls).
Lewy’s body-to-body sub-diagnosis
“” “It is believed that this disease affects at least 200,000 people in France, at least 150,000 people and at most 300,000”Says the specialist who raises the problem of the sub-diagnosis. “” “It is a disease that we have known recently. It was described for the first time in the 1970s by a Japanese colleague, Professor Osaka. Then, it was described clinically by our English colleagues, and in particular Ian McKeith in the 90s.”The first international criteria of the MCL will not arrive until 1996. According to Professor Blanc, France began to take an interest in this pathology in the 2000s, but it was not until 2010 to be really known .
Can we prevent the development of MCL?
“” “We do not know the causes of Lewy’s body disease. On the other hand, certain elements allow us to have an idea of risk factors, in particular thanks to colleagues from Mayo Clinic to Rochester in the United States.”These specialists have indeed shown that patients with MCL had several conditions in common:
-a stroke;
-Anxiety or depression: “I do not quite agree on this point, advance the white Professor. I think anxiety and depression are rather prodromal symptoms”, That is, symptoms that appear at the start of the disease. “” “We have shown it recently thanks to the French national cohort Memento”, He adds;
-Polipoprotein E4: “APO E4 is a gene that promotes Alzheimer’s disease and which could also promote Lewy body disease. But here too, we recently published with my team that the APO E4 was rather a risk factor The MCL associated with Alzheimer’s disease”;
-Avine family history of MCL or Parkinson.
Phthalates, pesticides, infection: other hypotheses on risk factors
Recently, by comparing patients with Lewy and Alzheimer’s disease, researchers have shown that there was more willingly the presence of phthalates in the former. These are microplastics decried because they are considered as endocrine disruptors and, for the most part, they are classified as “toxic substances for reproduction”. “” “It is not said that phthalates promote the emergence of MCL, we should go further in research”, Tempers the white Professor.
Hypotheses on an infectious origin of the MCL also circulate. For what ? “” “In all patients with Lewy’s body disease, including at the very beginning of the disease, there are bodies of Lewy in olfactory bulbs, that is to say in the nervous system of the nose. So we could imagine that there is a start of the disease that starts with the nose, perhaps what we inhale. This could be infectious or possibly linked to a toxic, such as phthalates”, Details the doctor.
Regarding the role of pesticides, for which several studies have shown the link with Parkinson and Alzheimer’s diseases, no research has yet been carried out for MCL.
