Chronic fatigue syndrome: investigation into a strange, still little-known illness

Chronic fatigue syndrome (or "CFS") isn't a disease that gets a lot of attention. It can be confusing when you hear or read "chronic fatigue" here and there, but CFS is indeed a disease in its own right, and not a state of temporary fatigue. This syndrome has only been recognized as a disease for a relatively short time, which may explain the gray areas surrounding it. Of course, we're not looking here at a rare form of apologia for laziness, or even a mysterious and tiring hair on the hand. Unfortunately, the chronic fatigue in question here is something else entirely, difficult to understand for both doctors and patients, and its origins are still uncertain. The doubts surrounding it and its relative "newness" as a recognized disease mean that it must be considered with caution, and that individuals who might suffer from it must be treated on a case-by-case basis, as there is no certainty to date regarding its treatment.

How can chronic fatigue syndrome be defined?

Chronic fatigue syndrome (" CFS "), also known as myalgic encephalomyelitis (" ME "), is a neurological condition characterized by a recurring state of exhaustion for those who suffer from it. This state of intense and persistent fatigue is long-term. Sufferers are unable to eradicate this feeling of general fatigue despite hours of sleep (non-restorative sleep), which leads to a deterioration in their overall health. Victims of CFS-ME often feel misunderstood because of the difficulty in identifying it and not confusing it with a simple state of temporary fatigue, or sometimes, unfortunately, considering it as a fictitious fatigue that is more akin to laziness.

This disease, called "systemic" (abnormal activation of the immune system), is considered neurodegenerative and involves intolerance to physical and cognitive effort . It took time to identify it as a disease because fatigue is a symptom of many diseases. Its diagnosis is therefore complicated. References to CFS-ME can be found as early as the 1750s, but this syndrome has only been considered a disease since 1985, and recognized by the WHO ("World Health Organization") since 1992.

According to the AFSC ¹ (“French Association of Chronic Fatigue Syndrome”), there are currently “ 3 main clinical diagnoses of CFS-ME ”, namely:

• the 2015 IOM (Institute of Medicine of the National Academies) criteria defining “Systemic Exertional Intolerance Disease or Syndrome” (“SISE” or “SISE”)
• the consensus criteria for myalgic encephalomyelitis , dating from 2011
• The Fukuda criteria , dating from 1994, are the most used criteria for defining CFS

As an aside, the first references to CFS date back to the 1750s, and it has been given many names to this day, including "post-viral syndrome", "neurasthenia" (described by neurologist GM Béard in the 19th century or used by Dostoevsky to describe the hero of " Crime and Punishment "), or even more surprisingly, "yuppie syndrome" in the 1980s (for "Young Urban Professionals", as it mainly affects 20-40 year olds). CFS, or when fatigue becomes a source of inspiration!

Chronic fatigue syndrome in figures

CFS-ME is not an easy disease to diagnose, and therefore to quantify. Nevertheless, research published in 2020 ² in the " Journal of Translational Medicine " cross-referenced statistics from different studies over the last 40 years, thus providing a fairly precise idea of ​​the prevalence of chronic fatigue syndrome . This is very low: 0.89% of the population using the Fukuda criteria ³ . This cross-sectional study also makes it possible to identify certain trends:

• the prevalence is 1.5 to 2 times higher for women than for men
• CFS-ME is more common in 18-40 year olds (the famous yuppies!)

An article in La Revue Médicale Suisse ⁴ corroborates this prevalence rate relatively well, estimating it at between 0.3 and 0.9%.

What causes chronic fatigue syndrome?

As for the causes of CFS-ME , let's be clear, this is where a large part of its mystery lies! Many theories have "competed" to identify the causes of this illness: psychological, infectious, even nutritional. The problem stems partly from the fact that CFS-ME has pathophysiological convergences with other related illnesses , for example fibromyalgia , depression or somatoform disorders (mental disorders characterized by physical symptoms). It is therefore quite difficult to identify the actual causes of chronic fatigue syndrome, as they are so common with other illnesses.

However, all is not lost! Indeed, a relatively recent shift in the way CFS-ME is viewed and studied has led to significant progress in identifying its origins. Recent and current studies finally seem to be converging and tend to highlight a dysfunction of the immune system as the cause of chronic fatigue syndrome, following a viral or bacterial infection. The resulting oxidative stress could then be at the root of the problem ⁵ .

Furthermore, a study conducted by Dr. M. Hornig of Columbia's Mailman School of Public Health has successfully demonstrated the biological origin of CFS-ME, notably by identifying two biomarkers (2 pro- and anti-inflammatory cytokines) present in abnormally high quantities in cases of CFS-ME. He concludes: " We now have evidence confirming what millions of people with this disease already know: CFS is not psychological! " This facilitates the use of biological diagnostic markers, even if these studies still require further study and confirmation.

Furthermore, the idea that the biological origin of chronic fatigue syndrome may come from "the gut, not the head" is increasingly favored, as illustrated by this 2016 study published in the highly regarded " Microbiome ⁶ ," which states that the results "indicate dysbiosis of the gut microbiota in this disease and further suggest an increased incidence of microbial translocation, which may play a role in the inflammatory symptoms of CFS-ME." Thus, a bacterium such as Helicobacter pylori would prove to be a cause of infection and inflammation (gastritis) at the origin of chronic fatigue syndrome.

It should also be noted that chronic fatigue can "be a sign of damage to an organ system caused by alcohol " as revealed in an article in the "Revue Médicale Suisse" from 2015 ^7. Excessive alcohol consumption would therefore be linked to the quality of sleep (disruption of the circadian rhythm), and would also be a potential cause of CFS-ME due to its negative impact on the body.

Finally, sleep apnea could also have a causal link with chronic fatigue syndrome, as explained in the 2015 Canadian Consensus Summary ⁸ : “ a number of patients may suffer from upper airway obstruction and sleep apnea .” Here too, a causal link is observed because it has been proven that an inflammation marker such as CRP (“C-Reactive Protein”) increases in the context of sleep apnea . The decrease in the ability to adapt to stress then leads to fatigue.

As we can see, the causes of chronic fatigue syndrome are as varied as they are numerous and often converge with other pathologies or sleep disorders :

• systemic inflammation
• immunodeficiency
• alteration of the intestinal microbiome
• neurological inflammation
• metabolic abnormalities
• damage to the organic system

From the depths of our stomachs to the loudest sleep apnea, fatigue lurks everywhere, but not in our heads. Except perhaps in the imaginations of writers!

Symptoms and Diagnosis of CFS-ME

To define chronic fatigue syndrome and characterize its symptoms, we will focus here on the Fukuda criteria , the latter being the most commonly used and being most referenced. They are as follows:

• intense and persistent fatigue for more than 6 months , not relieved by rest
• reduction in daily activities of at least 50%

At least 4 of the following symptoms must be added:

• sore throat , rhinitis
• joint pain , muscle pain
• cognitive disorders (memory, concentration)
• headaches
• unrestful sleep
• swollen lymph nodes in the neck and armpits
• discomfort after exercise (lasting more than 24 hours)

Other symptoms may be considered, such as those in the " Canadian Consensus on ME-CFS ." These include chronic fatigue and post-exertional fatigue, sleep disturbances, and the presence of significant pain. In addition, the patient must also have at least two cognitive or neurological symptoms, as well as at least one endocrine, immune, or autonomic symptom (difficulty remaining upright, dizziness, palpitations, etc.).

Given the multitude of symptoms and the difficulty in identifying its causes, how can chronic fatigue syndrome be diagnosed? For such a disease, with such characteristics, it is necessary to eliminate the many other "fatiguing" diseases before being able to identify CFS-ME, for example fibromyalgia, hypotension, mononucleosis, or even hypothyroidism. This is called an exclusive diagnosis (nothing to do here with an analysis of fidelity in the couple or with any kind of global exclusivity, as you will have understood!). This diagnosis can be carried out in a hospital setting.

There have been some encouraging advances in diagnosing this disease, as revealed by the study conducted by members of Cornell University in the United States ⁹ , published in " Microbiome " and cited above. This study describes a simple, "non-invasive and accurate in 83% of cases" diagnosis to detect CFS-ME through the analysis of stool and blood samples, by searching for biological markers (in intestinal bacteria and microbial inflammatory agents in the blood).

Diagnosing this chronic fatigue syndrome can therefore lead to "in-depth" and colorful explorations, to say the least! But it has the merit of facilitating the prevention of this disease with serious consequences for the daily life and health of patients.

What are the treatments for chronic fatigue syndrome?

The uncertainty about the exact causes of CFS-ME means that there is no "classic" or "systematic" treatment. The doctor is competent, on a case-by-case basis, to find a treatment that best matches the profile of the patient. On the other hand, this disease requires the patient to actively participate in the treatment process .

Although no specific treatment has clearly demonstrated its effectiveness, it is nevertheless possible to relieve symptoms in order to reduce physical and mental fatigue. The goal is to "empower" the patient by teaching them to maximize their autonomy in order to maintain a level of physical and intellectual activity sufficient for their well-being. Thus, many approaches exist to combat fatigue and muscle pain, for example:

• healthy lifestyle : regularly practice physical activity for very short periods (2-3 minutes), watch your diet (avoid excessive consumption of fast sugars which, once assimilated, make the body's energy "drop" too quickly)
• avoid overwork and stress as much as possible
• plan your activities according to your “peak” fitness (specific to each person, but generally between 10 a.m. and 2 p.m.)
• avoid caffeine and alcohol consumption
• ensure a sufficient intake of vitamins and magnesium
• have a regular sleep cycle (as much as possible)
• practice relaxation (“ Hoomband ” can be a very good ally!), yoga, sophrology, meditation…
• participate in support groups

In addition to these behavioral self-management measures, it is essential to treat certain pathologies:

• treat sleep disorders , including sleep apnea
• treat allergies , especially rhinitis
• monitor the balance of intestinal flora : examinations, regular screenings
• regularly treat infectious sources : teeth, sinuses, etc.

All of these recommendations are part of a logic of medical monitoring with the doctor, the latter helping the patient to practice a self-therapy strategy in order to learn to anticipate and adapt to their own constraints linked to chronic fatigue syndrome.

In addition, it is also possible to relieve the symptoms of CFS-ME through drug treatment , in agreement with your doctor, and with certain risks of side effects to take into account:

• pain: analgesics, paracetamol, aspirin, ibuprofen
• fatigue: methylphenidate, modafinil, vitamin B12
• cognitive disorders: methylphenidate, nimopidine, dextroamphetamines

Its exact causes are still uncertain, but progress has been made in recent studies, and its serious consequences for the daily lives of sufferers can be partially alleviated by various approaches. Chronic fatigue syndrome is a recent illness in scientific terms, protean, and which still requires a lot of attention from scientists, but also from sufferers who must learn how to live better with it. Everyone can find motivation and inspiration by imagining themselves as a character from Pagnol or Dostoyevsky, a tired or sick hero, but how memorable!

To get a better idea of ​​what CFS-EM is like, here is a video excerpt from a documentary made by Jennifer Brea , posted on the website " EMaction ". The film from which this excerpt is taken, " Unrest ", is autobiographical and very inspiring, showing us what life with this illness is like.

To delve deeper, here is an article and video that explain the progress made in identifying chronic fatigue syndrome as a biological disease, with a contribution from Dr. Mady Hornig, an American psychiatrist and associate professor of epidemiology at the Mailman School of Public Health at Columbia University.

On a lighter note and to illustrate the “plan your activities” and “avoid overwork” approach, here is an extract from the film “Alexander the Blessed” , which will perhaps give hope to all the tired people of the world!

Sources:

[1] Chronic Fatigue Syndrome or Myalgic Encephalomyelitis? , website “Association Française du Syndrome de fatigue Chronique”, 2020 [2] Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) , EJ Lim, YC Ahn et al, “ Journal of Translational Medicine ”, February 2020 [3] Fukuda criteria , website “ME-Pedia”, 2020 [4] and [5] Chronic fatigue syndrome , A. Gonthier, B. Favrat, “Revue Médicale Suisse” (volume 11), 2015 [6] and [9] Reduced diversity and altered composition of the gut microbiome in individuals with myalgic encephalomyelitis/chronic fatigue syndrome , L. Giloteaux, JK Gooodrich et al, “ Microbiome ”, 2016 [7] Fatigue in cases of dependency diseases , C. Aichmüller, M. Soyka, “ Swiss Medical Review”, 2015 [8] Summary of the Canadian Consensus, Dr BM Carruthers, MI Van de Sand, “Asso-SFC” website, 2020