Skip to main content

Or 34,00 After 66% tax deduction

I make a monthly donation I make an IFI donation
Research, science & health

Multiple sclerosis: new study highlights five warning signs of the disease

Published on: 06/12/2023 Reading time: 1 min
sclérose en plaques

What if the biological mechanisms that cause multiple sclerosis were triggered years before clinical diagnosis? This is what a team at Paris Brain Institute suggests in a new study published in Neurology. The researchers show that, on a population scale, the frequency of disorders such as depression, constipation, and urinary tract infections is associated with a diagnosis of multiple sclerosis five years later. These results outline a prodromal phase of the disease, but at this stage, they do not allow for the development of an early detection technique.

Multiple sclerosis (MS) is a neurological disease in which the immune system attacks myelin, the protective sheath of nerve fibers, which plays a critical role in the spread of nerve impulses between the brain and peripheral organs. In France, 120,000 people are affected by MS, whose management has improved considerably over the last ten years. Unfortunately, there is still no cure to speak of—and no therapeutic solution at all for the 15% of patients with a progressive form.

“One of the major difficulties with multiple sclerosis is that we do not observe a strict correspondence between the severity of lesions on nerve fibers and patients’ symptoms. This considerably limits our ability to predict the course of the disease. The challenge today is to detect the disease as early as possible, well before the lesions are visible on MRI, in the hope of delaying the onset of disability.”

Céline Louapre (Sorbonne University, AP-HP), a neurologist at Pitié-Salpêtrière Hospital and head of Paris Brain Institute’s clinical investigation center

Several studies have already suggested that, in some patients, subtle symptoms were present up to ten years before diagnosis. What remained was to quantify this phenomenon at the population scale to rigorously define a “prodromal phase” of multiple sclerosis, i.e., a period during which the disease takes hold discreetly. In addition, a better understanding of the early symptoms of MS could help researchers pinpoint the exact moment when the inflammatory process that causes lesions in the central nervous system begins.

 

Leveraging massive epidemiological data

To this end, Pr. Céline Louapre, accompanied by Octave Guinebretière and Thomas Nedelac, researchers at Paris Brain Institute as part of the ARAMIS team led by Stanley Durrleman (Inria), compared the health data of 20,174 patients with multiple sclerosis, 54,790 patients without multiple sclerosis, and 37,814 patients affected by two autoimmune diseases which, like MS, mainly affect women and young adults—namely 30,477 patients with Crohn’s disease and 7,337 with lupus.

Using anonymized medical records from the UK’s Health Improvement Network (THIN), the team analyzed the health trajectory of these patients, focusing on the frequency of 113 common symptoms and illnesses over five years before and five years after diagnosis. A similar reference period was used for control patients without autoimmune disease.

The researchers observed that five symptoms were significantly associated with a later diagnosis of multiple sclerosis: depression, sexual disorders, constipation, cystitis, and other urinary tract infections. “This association was sufficiently robust at the statistical level for us to state that these are early clinical warning signs, probably related to damage to the nervous system, in patients who will later be diagnosed with multiple sclerosis,” Prof. Céline Louapre explains. “The overrepresentation of these symptoms persisted and even increased over the five years after diagnosis.”

 

Shedding light on the trajectory of the disease

However, these five symptoms also appeared in the prodromal phase of lupus and Crohn’s disease, which means they are not specific to MS. Most importantly, they are also widespread in healthy people.

“These signs alone will not be enough to make an early diagnosis, but they will certainly help us better understand the mechanisms of multiple sclerosis—which has many causes—and reconstruct its natural history,” she adds. “Finally, these new data support the idea that the disease begins well before the onset of classic neurological symptoms.”

Céline Louapre

Only a tiny fraction of people who experience depression, sexual problems, constipation, and urinary tract infections will be diagnosed with an autoimmune disease a few years later. But in populations with a specific risk—in certain familial forms of multiple sclerosis, for example—these signs will help to give early warning and perhaps lead to therapeutic intervention.

 

Funding

This study was funded by the Joint Programming on neurodegenerative diseases (JPND) of the European Union, the Investments for the Future program, and tANR.

Sources

Guinebretière, O. et al. Association between diseases and symptoms diagnosed in primary care and the subsequent specific risk of multiple sclerosis. Neurology, 6 décembre 2023. DOI : 10.1212/WNL.0000000000207981.

Our news on the subject

Interneurones. Crédit : UCLA Broad Stem Cell Research Center.
Stimulating specific neurons in the striatum stops compulsive behaviour
What if we could resist compulsions? These irrational behaviours, particularly common in obsessive-compulsive disorder (OCD), are hard to suppress. At Paris Brain Institute, Éric Burguière's team shows that we can anticipate them and block them...
09.10.2024 Research, science & health
Les nerfs moteurs présents dans la moelle épinière se projettent vers la périphérie, où ils entrent en contact avec les muscles, formant des connexions appelées jonctions neuromusculaires. Crédit : James N. Sleigh.
Ultrasound show unexpected effects on motor neuron disease
Over the past fifteen years, neurosurgeons have been perfecting a fascinating technique: using ultrasound to temporarily open the blood-brain barrier to facilitate the action of therapeutic molecules in the central nervous system. At Paris Brain...
09.05.2024 Research, science & health
Un neurone
Rett syndrome: a new gene therapy on the way
Gene therapy could be our best chance of treating Rett syndrome, a neurological disorder that causes severe intellectual and motor impairments. At Paris Brain Institute, Françoise Piguet and her colleagues have looked closely at brain cholesterol...
07.16.2024 Research, science & health
Lésions d’un patient à l’inclusion dans le protocole (M0) disparues après 2 ans de traitement à la Leriglitazone (M24)
The dual effect of leriglitazone in X-linked Adrenoleukodystrophy (X-ALD)
In 2023, the team led by Professor Fanny Mochel (AP-HP, Sorbonne University), a Paris brain Institute researcher, showed that daily dose of leriglitazone slow down the progression of myelopathy in patients with X-linked adrenoleukodystrophy, and...
06.28.2024 Research, science & health
Une tête de statue de l'île de Pâques sur laquelle sont posées des éléctrodes
A multimodal approach to better predict recovery in patients with disorders of consciousness
When a patient is admitted to intensive care due to a disorder of consciousness—such as a coma—establishing their neurological prognosis is a crucial yet challenging task. To reduce the uncertainty that precedes the medical decision, a group of...
05.30.2024 Research, science & health
Population de bactéries commensales (en rouge) dans un intestin grêle de souris. Crédit : University of Chicago
The composition of the gut microbiota could influence decision-making
The way we make decisions in a social context can be explained by psychological, social, and political factors. But what if other forces were at work? Hilke Plassmann and her colleagues from the Paris Brain Institute and the University of Bonn show...
05.16.2024 Research, science & health
See all our news