What is PEM, POTS and MCAS

Uit research it appears that 84% of people with post-COVID suffer from post-exertional malaise (PEM). PEM is the worsening of complaints such as extreme fatigue, muscle and joint pain, concentration problems and general malaise after physical, cognitive and/or emotional exertion. In addition to the worsening of existing complaints, it can also lead to previously unoccurring physical and/or cognitive complaints. Complaints can arise acutely or develop 12-48 hours after physical, cognitive and/or emotional exertion. These complaints can last for days or sometimes even weeks, with the risk of long-term relapse if PEM is repeatedly provoked. In particular, the exhaustion that occurs for a considerable time after the exertion is typical of PEM.

The severity and duration of the complaints that arise are not in proportion to the level of exertion, also called exertion intolerance. PEM plays an important role in reasons why patients can no longer participate properly in society.

Pacing

Pacing is a technique to prevent or learn to cope with PEM. It helps to control symptoms and prevent the worsening of complaints. Pacing teaches people to recognize their physical and cognitive limits, so that they can live as active a life as possible within those limits.

Pacing is performing an activity at a calm pace, where it is important to alternate this accurately with a rest period. This is to stabilize and reduce complaints. It is important to stay within the individual limits and to perform activities in such a way that complaints do not arise or worsen. It is applicable to daily and physical activities and activities that require concentration.

Read more about PEM and Pacing in the factsheet below.

Indication for PEM

There is a PEMcheck available. This recognized self-test gives an indication (not a diagnosis) whether there is reason to look further into the exercise intolerance.

Please note: The Fatigue Clinic has translated the NIH/CDC DePaul Symptom Questionnaire (DSQ) and digitized the 5 additional questions on PEM (DSQ-5) for ease of use. Once completed, it leads to promoting their own institution. 

Research

There is also a study published in October 2023 on exercise intolerance and post-exertional malaise in patients with post-COVID. More on this via the link below.

Our body consists of multiple nervous systems; the central and peripheral nervous systems. The peripheral nervous system forms the connection between the central nervous system, the muscles and the organs, and is divided into the somatic and autonomic nervous systems. The somatic nervous system regulates bodily functions that can be consciously controlled, such as talking and moving. The autonomic nervous system, on the other hand, regulates everything in your body that you don't have to think about, such as your heart rate, breathing, blood pressure, digestion, body temperature, etc.

What is dysautonomia?

Dysautonomia is an umbrella term used to describe several conditions in which the autonomic nervous system is disturbed. The autonomic nervous system does not function properly. There are several causes of dysautonomia, including post-infectious syndromes such as post-COVID, QVS and ME/CFS, but also conditions such as Parkinson's disease. Dysautonomia occurs mainly in women.

Different forms of dysautonomia

1. Dysfunctional breathing: a breathing pattern that is not optimal and may be characterized by irregularities in the frequency, depth, and rhythm of breathing.
2. Bradycardia: a heart rate that is (on average) too low. The heart may not be able to pump enough blood. In some patients, the heart is not able to supply the body with enough oxygen-rich blood during exercise.
3. Orthostatic intolerance (OI) is an umbrella term for the development of complaints when changing posture (sitting/standing) due to changes in blood pressure or heart rate. OI has several manifestations:
   1. Orthostatic hypotension (OH): sudden drop in blood pressure when standing or sitting up, with dizziness due to disturbed blood circulation.
   2. Orthostatic hypertension: sudden increase in blood pressure when standing or sitting up.
   3. Inappropriate sinus tachycardia: inappropriately increased heart rate.
4. Postural orthostatic tachycardia syndrome (POTS)
   Patients may experience symptoms of orthostatic intolerance to such an extent that guidance and treatment are necessary.

Uit research shows that 32% of post-COVID patients have evidence of POTS. People feel unwell when changing position, such as standing or sitting up, and have a sudden abnormal increase in heart rate (tachycardia) while blood pressure remains the same.

This often causes various other complaints (including palpitations, fainting, headache, fatigue, gastrointestinal complaints, sweating and general malaise). autonomic nervous system, which controls organs such as the heart, lungs and blood vessels, does not work properly. When we stand up, some of our blood sinks due to gravity. In healthy people, the autonomic nervous system corrects this. In POTS, this does not work sufficiently and the body often compensates for the shortcoming in the supply of blood to the heart. The heart starts beating even faster. The blood pressure is maintained by this accelerated heart rate. This compensation mechanism often prevents a POTS patient from fainting, but the heart still fails to pump enough oxygen-rich blood to the brain and some organs. As a result, people cannot function properly when standing. This means that they are forced to spend a large part of the day lying down.

Treatment

Treatments include proper education, nutritional and exercise advice, and possibly medication that can control the heart rate or increase intravascular volume.

More information can be found in the factsheet below and the website this is POTS.

Please note: The advice, also in the fact sheet, is to look at the guidance with a treating physician. Too much NaCL ('salt') intake can namely lead to a potassium problem or too high blood pressure etc. A physician can monitor, make choices and make lab requests to check certain values ​​if necessary.

Idiopathic MCAS is a condition in which mast cells in the body are inappropriately activated and release substances. This causes a wide range of symptoms that often resemble allergic reactions. Examples include skin complaints such as redness and itching, circulatory complaints such as low blood pressure and fainting, gastrointestinal complaints such as abdominal cramps and diarrhea, respiratory complaints such as a stuffy or itchy nose, and other complaints such as fatigue, concentration problems and a general feeling of being unwell.

How does MCAS develop?

Mast cell activation can be caused by a variety of factors, including mast cell disorders, allergies, certain tissue diseases, and hives. MCAS is a complex immune system disorder in which mast cells (immune cells) overreact to things that normally pose no threat. The cause of MCAS is unknown. In some people, temperature changes, stress, or exercise can trigger an attack. After a COVID-19 infection, symptoms may also persist due to long-term inflammation. Mast cells play an important role in the immune system in acute COVID-19.

Diagnosis

To determine MCAS, the following four things must apply:

1. There are persistent complaints caused by the release of substances by mast cells in at least two different organs, without a clear allergy.
2. The symptoms improve or disappear when medication is used that targets the substances produced by the mast cells.
3. During an attack, markers of mast cell activation in the blood or urine rise.
4. Other causes of mast cell activation, such as allergies, have been ruled out.

Treatment

Treatment consists mainly of avoiding triggers, such as allergens, temperature changes, exercise or stress. In case of severe symptoms, medication, such as antihistamines, can be considered.

More information about MCAS can be found on the website of MCAS Netherlands, see link below.