Chronic Fatigue Syndrome (CFS) is a rare and very serious disease that strongly limits the ability to perform daily activities, and in more severe forms leads to inability to work and disability. Its global incidence varies between approx. 0.3-0.6 percent. The COVID-19 pandemic has noticeably contributed to the increased incidence of CFS.

The symptom of CFS is an extreme, overpowering, feeling of exhaustion. Patients do not sleep well, feel exhausted around the clock, suffer from headaches, muscle and joint pain, have problems with memory and concentration. They are unable to make physical effort, and often even to get out of bed.

Precise diagnostic markers for CFS have not yet been developed; there are no uniform criteria for its diagnosis. There is also no specific medication for this disease.

“Ten years ago I was on an internship in Newcastle and I first came into contact with people suffering from CFS. Those patients had very characteristic symptoms of dysautonomia, an autonomic nervous system disorder. This interested me and after my return, together with my team, we were the first in Poland to look for such patients and run the first projects with their participation. As far as I know, it still is not a popular topic in Poland,” says Professor Paweł Zalewski from the Collegium Medicum of the Nicolaus Copernicus University in Toruń.

Zalewski and his colleagues from the Department of Exercise Physiology and Functional Anatomy published the results of their research in the Journal of Translational Medicine(https://doi.org/10.1186/s12967-022-03460-1).

The researchers have determined that whole body cryotherapy, especially when combined with static stretching exercises, is a very promising treatment approach for CFS. The authors emphasize that this is an important therapeutic indication, given the lack of any other effective therapeutic options for patients with CFS and the lack of ways to eliminate the symptoms that often lead to disability.

“We took up this topic because we were driven by the desire to help the patients in a very difficult situation,” says Professor Zalewski. “Even the diagnosis of the disease is complicated, we do not have specific biomarkers for it. Nor can we offer them any specific drug treatment. There are some attempts, doctors try to intervene, but there is no targeted, specific treatment for this syndrome, one that would improve the functioning of patients.” 

THE PANDEMIC HELPED

The professor explains that the symptoms of CFS are very non-specific. They are a mosaic of various ailments, most likely with viral etiology - just like in the case of COVID-19.

“Ironically, the COVID pandemic has aided CFS patients,” says the first author of the paper. “Post-COVID symptoms are very similar to the symptoms of chronic fatigue syndrome. In recent months, there have been quite a few publications in the scientific literature on the links between CFS and post-COVID syndrome. The more ideas appear to relieve people suffering from long COVID-19, the more chances we have of finding a solution to the problem of CFS patients.”

Among the symptoms that are characteristic of both of these diseases, the professor mentions cognitive impairment, short-term memory deterioration, attention and processing disorders, sleep disorders, chronic fatigue, and even language fluency disorders and symptoms of dysautonomia. In other words, what we call 'brain fog' in COVID-19 is a daily reality for all CFS patients.

THE COLD AND THE NERVOUS SYSTEM

According to Professor Paweł Zalewski, whole body cryotherapy activates physiological mechanisms aimed at maintaining a constant body temperature. Its anti-inflammatory effectiveness has also been proven. Previous research by the team from the Nicolaus Copernicus University also showed a strongly stimulating and regulating effect of low temperatures on the autonomic nervous system (ANS), especially its parasympathetic part. The cold first strongly activates the sympathetic nervous system, while in the long term it has a toning effect and normalizes the sympathetic-parasympathetic balance.

Since ANS dysfunction is observed in the course of CNS, scientists decided to combine these facts.

EXERCISES TAILORED TO CAPABILITIES

“Usually, the methodology of cryotherapy uses exercises that enhance its effects,” Zalewski says. “Most of these are aerobic exercises, e.g. cardio. In this case, however, we could not use them, because one of the most important clinical symptoms of CFS is pathological exercise intolerance. So we started looking for other forms of working with the body.”

In addition, scientific evidence shows that static stretching can increase the activation of mitochondria, which are an important components of the muscle cells and provide them with the energy needed to work (contract).

Scientists already knew that people with CFS had lower mitochondrial function for unknown reasons. Delicate stretching would tone down and calm the body after such a strong stimulus as cryostimulation, and secondly, improve the work of mitochondria.

THE RESULTS ARE PROMISING

The study participants included 32 CFS patients and 18 healthy patients. For two weeks, they all participated in a program that included a total of 10 sessions of stretching exercises followed by cryotherapy (from several dozen seconds at the beginning to three minutes during the last sessions).

It turned out that the CFS group had a significant reduction in perceived fatigue and sleepiness. In addition, some aspects of cognitive functioning (e.g. speed of visual information processing) improved.

“Our patients had a subjective sense of greater energy reserves. They reported improved functioning. From the physiological point of view, we noticed a marked improvement in cardiac function, blood pressure regulation and improvement of the autonomic system, i.e. alleviation of the symptoms of dysautonomia,” says the author of the study.

“We also have collected biological material that we will study in various centres around the world to find out what molecular mechanisms were at work here. But for that, we first need to raise funds,” he adds.

The study confirms that whole body cryotherapy is well tolerated by people with CFS and leads to symptomatic improvement associated with changes in cardiovascular and autonomic function.

The researchers emphasize that given the preliminary data showing the beneficial effect of cryotherapy, its relative ease of application, good tolerability, and proven safety, therapy with cold exposure appears to be an approach worth attention. “Further studies of cryotherapy as a potential treatment in CFS is important in the light of the lack of effective therapeutic options for these common and often disabling symptoms,” they write in the Journal of Translational Medicine.

Positive effects of the applied treatment persisted in patients for several weeks. After this time, the procedures should be repeated. According to Professor Zalewski, from the scientific point of view, this method is very beneficial.

“Importantly, it can be applied to basically anyone,” he says. “The cold is healthy; such exposures are always beneficial. In addition, cryotherapy differs from cold baths in that ice, snow and cold water are associated with strong pain sensations. There is no pain in cryostimulation, because the so-called dry cold affects the body.”

SMALL REASON, BIG PROBLEM

Zalewski adds that chronic fatigue syndrome is an extremely rare disease and unfortunately - especially in some countries - it is affected by the problem of overdiagnosis. The problem is exacerbated by the fact that CFS does not have a homogeneous picture and can be very different in different people, although it does have common features. There are always strong, somatic symptoms.

“COVID-19 is a bit different, because we have antibodies based on which we can say that it is this disease; the body produces specific antibodies,” Zalewski says.

“But both COVID-19 and post-COVID syndromes that are now being studied so intensively certainly contribute to bringing us closer to finding ways to help people with CFS.

“The method we are talking about could potentially benefit not only patients with chronic fatigue syndrome, but also people with the now common long COVID.”

He adds that many CFS patients struggle with their symptoms being trivialized and misunderstood. “They hear that everyone is tired these days. Meanwhile, this is not a typical physiological or behavioural fatigue. This is a pathological fatigue that does not reverse in the normal regeneration process,” he says.

In some patients, chronic fatigue syndrome leads to complete deterioration and death, also in children. In a large group of patients, the disease occurs in alternating periods of remission and deterioration. A very small percentage of patients fully recover.

As for the genesis of CFS, in the case of some patients it is possible to identify the exact time point of the viral infection that caused the first symptoms. However, there are also those in whom such a situation cannot be identified because many infections have a subclinical course, they are asymptomatic or mildly symptomatic.

PAP - Science in Poland, Katarzyna Czechowicz

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