Physician Resources
The diagnostic process for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) can be very long and trying for both doctor and patient, but it doesn’t have to be if you learn to identify the criteria for diagnosis. In fact, patients with the best prognosis are those who are diagnosed early, because ME/CFS can get much worse permanently when people with the illness try to do as much as they want or need to do. We hope the following information will be of assistance to you and your patients. Please feel free to share this website with your colleagues and help us raise awareness about ME/CFS.
ME/CFS is a complex, debilitating, neuro-immune, neuroinflammatory disease resulting in significant endocrine, cardiovascular, neurological, and autonomic abnormalities (WHO), as well as immunologic and energy metabolism impairments. It is recognized as an invisible illness by Manitoba Possible and the Government of Manitoba Accessibility Legislation. The cause is unknown, although ongoing research illustrates definite physiological abnormalities. In many cases, ME/CFS is preceded by a viral illness or an untreated bacterial infection from which the patient never recovers. Patients live in isolation and most are unable to work due to the unrelenting exhaustion, cognitive impairment, and many other severe and life-altering symptoms.
ME/CFS affects over half a million Canadians (STATS CANADA), and can be diagnosed in children as well as adults. Prevalence is growing as the current pandemic has revealed that the SARS-CoV-2 virus (that causes COVID-19) is one of the many viruses capable of triggering the myriad of symptoms present in patients living with ME/CFS. In fact, many with Long Covid meet the criteria for a diagnosis of ME/CFS as well, but are not always receiving a timely diagnosis. The defining characteristic/cardinal symptom of ME/CFS is Post-Exertional Malaise (PEM).
What is Post-Exertional Malaise (PEM)?
PEM is an exacerbation of some or all of a patient’s symptoms and a further reduction in functioning after physical, cognitive, orthostatic, emotional, or sensory challenges that were previously tolerated. It is important to note that PEM is much more than just fatigue. Although worsened fatigue can be one of the symptoms of PEM, PEM is a combination of several to many severe symptoms (ex. sore throat, enlarged lymph nodes, feeling feverish, migraine, nausea, dizziness, shortness of breath, loss of appetite, muscle pain, limb heaviness, worsened sleep disruptions, inability to think without pain, muscle weakness, and many other symptoms) that make daily functioning extremely difficult or impossible. PEM is often referred to as being in a “crash,” experiencing a “flare” of symptoms, or a “relapse.”
PEM is characterized by the following:
Immediate or delayed onset. Onset may be immediate or delayed by hours to days after the challenge.
Prolonged duration. Days, weeks, or months may pass before patients return to their previous baseline.
Disproportionate intensity. The intensity and duration of PEM are unexpectedly disproportionate to the magnitude of the PEM trigger. For the mildly ill, working a few hours or a day can trigger PEM, whereas for the most severely ill, even the most basic activities of daily living or just trying to communicate, as one example, will be sufficient to trigger PEM.
“People with ME/CFS are often not able to do their usual activities. At times, ME/CFS may confine them to bed. People with ME/CFS have overwhelming fatigue that is not improved by rest. ME/CFS may get worse after any activity, whether it’s physical or mental. This symptom is known as post-exertional malaise (PEM).” - CDC
By asking the right questions or listening to specific comments from your patients describing their symptoms and fatigue, you can learn to identify Post-Exertional Malaise (PEM) in your patients.
Examples of questions are listed in the “Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Essentials of Diagnosis and Management: (first link immediately below in red). For example, if your patient tells you that going out shopping results in terrible fatigue and/or flu-like symptoms afterwards, this could be a clue that your patient is experiencing Post-Exertional Malaise, the cardinal symptom of ME/CFS.
SUGGESTED DIAGNOSTIC RESOURCES
** Myalgic Encephalomyelitis/Chronic Fatigue Syndrome:
Essentials of Diagnosis and Management **
(Published November, 2021)