Sleep disorders, first signs of Charcot’s disease?

To date, there is no treatment to treat Charcot’s disease which leads to the death of the patient within 3 to 5 years of the appearance of the disease. Amyotrophic lateral sclerosis (SLA) or Charcot disease is a neurodegenerative disease linked to the progressive death of nerve cells called snowmobiler. This is responsible for a progressive and rapid atrophy of the muscles, the appearance of motor disorders and deficits behind the loss of autonomy of the patients. The damage of the respiratory muscles causes death.

As is the case for several other neurodegenerative diseases, researchers from Inserm and the University of Strasbourg have wondered if sleep disorders – induced by the evolution of the disease – could pre -exist in motor disorders and if The restoration of sleep could slow down the evolution of the disease. They thus analyzed dozens of sleep recordings of groups of people with SLA, at different stages of the disease – a group had not yet developed respiratory symptoms, another was the bearer of genetic mutations and presented an increased risk to develop the disease. These results were compared to those of control groups.

“These tests indicate that the two groups of individuals suffered from the same type of sleep disorders: a greater awakening time and a deep amount of sleep lower than the data from the control groups”, write the authors of the study in a press release, published Tuesday, February 4. The results, published in the newspaper Science Translational Medicinesuggest that sleep disorders are present and observable, and this early, several years before the manifestation of motor disorders.

Scientists then sought the origin of these sleep disorders in the brain. A track: Orexine neurons, specific hypothalamus neurons known to play a role in stimulating the state of awakening. In mouse models with ALS, in which the same sleep disorders have been observed, the researchers discovered that the neurons circuits where orexin neurons are integrated are altered, by the disappearance of annex neurons during the disease .

An orexin inhibitory molecule, already prescribed against insomnia, has been administered to sick mice. Results: After a single oral take the sleep of the mice was restored. The activity of annex neurons of orexin neurons was also restored and after 15 days of treatment, a preservation of motor neurons was observed in mice. The team of researchers now want to test the molecule in patients with SLA: can restoring their sleep brake the disease?

« The discoveries of our team are important on two levels. First of all, they highlight a new chronology of SLA symptoms, again questioning the origins of the disease, and in particular the role of the brain in its genesis, Explains Luc Dupuis, co-deeper author of the study. They also represent a slight hope for the patients, and those who declare the disease, imagining that Idag on the first manifestations of it can slow down its extremely rapid progression. »»