New Consensus Criteria for ME/CFS

The following is information and news published by Kim McCleary, the President of the CFIDS Association of America on the International Consensus Criteria Published for Myalgic Encephalomyelitis.  Excerpts and the link you will find below:

On July 20, 2011, the Journal of Internal Medicine e-published ahead of print “Myalgic Encephalomyelitis: International Consensus Criteria.” The panel of authors, led by coeditors Bruce M. Carruthers, MD, CM, FRCP(C) and Marjorie I. van de Sande, BEd, GradDip Ed, includes 26 authors from Australia (3 authors), Belgium (1), Canada (4), Chile (1), Ireland (1), Italy (1), Japan (1), Korea (1), Latvia (1), New Zealand (1), Norway (1), the United Kingdom (2) and the United States (8). The paper specifically cites 123 publications to support its recommendations.

The label “chronic fatigue syndrome” (CFS) has persisted for many years because of lack of knowledge of the etiological agents and of the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term “myalgic encephalomyelitis”(ME) because it indicates an underlying pathophysiology. It is also consistent with the neurological classification of ME in the World Health Organization’s International Classification of Diseases (ICD G93.3). Consequently, an International Consensus Panel consisting of clinicians, researchers, teaching faculty and an independent patient advocate was formed with the purpose of developing criteria based on current knowledge. Thirteen countries and a wide range of specialties were represented. Collectively, members have approximately 400 years of both clinical and teaching experience, authored hundreds of peer reviewed publications, diagnosed or treated approximately 50,000 ME patients, and several members coauthored previous criteria. The expertise and experience of the panel members as well as PubMed and other medical sources were utilized in a progression of suggestions/drafts/reviews/revisions. The authors, free of any sponsoring organization, achieved 100% consensus through a Delphi type process.

New Criteria Overview

ME is described as “an acquired neurological disease with complex global dysfunctions. Pathological dysregulation of the nervous, immune and endocrine systems, with impaired cellular energy metabolism and ion transport are prominent features. Although signs and symptoms are dynamically interactive and causally connected, the criteria are grouped by regions of pathophysiology to provide general focus.”

Of particular note is that other definitions have established a minimum duration of illness (either four or six months). The new ME definition removes this requirement: “…diagnosis should be made when the clinician is satisfied that the patient has ME rather than having the diagnosis restricted by a specified time factor. Early diagnoses may elicit new insights into the early stages of pathogenesis; prompt treatment may lessen the severity and impact.” One of the questions arising from the new definition is whether individuals with a more transient illness will be considered to have ME.

Diagnosis begins with assessment of post-exertional neuroimmune exhaustion (PENE), rather than fatigue. “Post-exertional neuroimmune exhaustion is part of the body’s global protection response and is associated with dysfunction in the regulatory balance within and between the nervous, immune and endocrine systems, and cellular metabolism and ion transport. The normal activity/rest cycle, which involves performing an activity, becoming fatigued, and taking a rest whereby energy is restored, becomes dysfunctional.”

In addition to the required feature of PENE, the individual must have seven other symptoms: three that demonstrate neurological impairment; three that demonstrate immune impairment; and one that demonstrates energy production/transport impairment. These are described more fully below. The term “atypical ME” is used when an individual “meets criteria for post-exertional neuroimmune exhaustion but has two or less than required of the remaining criterial symptoms. Pain or sleep disturbance may be absent in rare cases.”

The paper provides severity subgroups: “Symptom severity impact must result in a 50 percent or greater reduction of a patient’s premorbid activity level for a diagnosis of ME. Mild: approximately 50 percent reduction in activity; Moderate: mostly housebound; severe: mostly bedbound; and Very Severe: bedbound and dependent on help for physical functions.”

Special considerations are noted for making the diagnosis in the pediatric setting, including guidelines about distinguishing ME from school phobia.

The following co-occurring conditions are identified: “Fibromyalgia, myofascial pain syndrome, temporomandibular joint syndrome, irritable bowel syndrome, interstitial cystitis, Raynaud’s phenomenon, prolapsed mitral valve, migraines, allergies, multiple chemical sensitivities, Hashimoto’s thyroiditis, Sicca syndrome, reactive depression. Migraine and irritable bowel syndrome may precede ME but then become associated with it. Fibromyalgia overlaps.” From reading the text, it does not appear that this list is intended to represent the only comorbid conditions that should be considered. For instance, specific forms of orthostatic intolerance (postural orthostatic tachycardia syndrome and neurally mediated hypotension) are referenced in the description of energy production and transport impairments.

Symptom Clusters

As stated earlier, the central feature of ME under this definition is post-exertional neuroimmune exhaustion (PENE). To meet the criteria, an individual must have PENE, described in the following manner: “This cardinal feature is a pathological inability to produce sufficient energy on demand with prominent symptoms primarily in the neuroimmune regions.

“Characteristics are:
1. Marked, rapid physical and/or cognitive fatigability in response to exertion, which may be minimal such as activities of daily living or simple mental tasks, can be debilitating and cause a relapse.
2. Post-exertional symptom exacerbation: e.g. acute flu-like symptoms, pain and worsening of other symptoms.
3. Post-exertional exhaustion may occur immediately after activity or be delayed by hours or days.
4. Recovery period is prolonged, usually taking 24 hours or longer. A relapse can last days, weeks or longer.
5. Low threshold of physical and mental fatigability (lack of stamina) results in a substantial reduction in pre-illness activity level.”

The individual must demonstrate neurological impairment by meeting a total of at least three symptoms from three of these four categories:
1. Neurocognitive impairment
a. Difficulty processing information: slowed thought, impaired concentration
b. Short-term memory loss
2. Pain
a. Headaches
b. Significant pain can be experienced in muscles, muscle-tendon junctions, joints, abdomen or chest. It is non-inflammatory in nature and often migrates.
3. Sleep disturbance
4. Neurosensory, perceptual and motor disurbances
a. Neurosensory and perceptual
b. Motor

The individual must demonstrate immunological impairment by meeting a total of at least three symptoms from three of these five categories:
1. Flu-like symptoms may be recurrent or chronic and typically activate or worsen with exertion
2. Susceptibility to viral infections with prolonged recovery periods
3. Gastointestinal tract
4. Genitoruinary
5. Sensitivities to food, medications, odours or chemicals

The individual must have one of the following symptoms that demonstrate energy production/transport impairment:
1. Cardiovascular
2. Respiratory
3. Loss of thermostatic stability
4. Intolerance of extremes of temperature

Further descriptions of each of these symptom clusters are provided in Table 1 that accompanies the text. (Table 1 has been reproduced by the CFIDS Association of America under limited license from John Wiley & Sons, Inc., publisher of the Journal of Internal Medicine. Copyright to the original material and all other rights reserved by John Wiley & Sons, Inc.)

The authors also provide additional directives for applying these symptom lists in clinical settings vs. research settings. The panel is at work on Physicians Guidelines and an International Consensus Symptom Scale. They specifically state that only subjects who fully meet ME criteria should be included in epidemiological research.

To read the rest of the information, click the link below.


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  1. leorising says:

    Awesome link, thank you!

  2. From the article: From reading the text, it does not appear that this list is intended to represent the only comorbid conditions that should be considered. For instance, specific forms of orthostatic intolerance (postural orthostatic tachycardia syndrome and neurally mediated hypotension) are referenced in the description of energy production and transport impairments.

    I’m not understanding what Kim is saying here? My understanding is that PENE is a major part of the illness which is why it was placed under the descriptoin of energy production and transport impairments.

    Anyway, I also figured that since this is just step one, if you will, that this may be tweaked some.

    Thanks for posting this.

  3. Virginia says:

    I started this when I was working with a patient on Mucinex therapy. It worked, but I thought it was a fluke, and I stopped taking it. Months later, stiff and unable to get around and work without severe pain in my lower back and neck, stiffness in my hips and knees, and general achiness all over, I decided to give it another shot. I have Crohn’s disease which causes fibromyalgia symptoms. Since the Crohn’s didn’t seem to be negatively affected by the Mucinex, I started on it again last week. No pain in my lower back, still just a bit stiff in my neck. I am so happy that back pain is gone. I can do things again and not hurt. I don’t have to be on narcotics and I sleep like a baby. I recommend at least trying it.

  4. says:

    Fibromyalgia may or may not be real. Something is causing a lot of people to have physical pain and disability.
    I”m with the ones who say take the drug commercials off of TV. The pharmaceutical companies seem to be spending more on advertising than on R&D. No wonder prescription prices are sky-high.

  5. One of the statements about the new diagnosis that truly disturbed me,was while rating the stages, from mild to severe, that the definition of mild was 50 % decrease in activity. I don’t know about you, but 50% is ALOT to me. I suppose its partly relative, but I wouldn’t lose 50% of my activity and consider it to be mild. I have lost more than 50% personally, from fibromyalgia. I was almost offended reading about the definition of “mild”. As for the rest, I see progress being made here, at the very least by a more concise definition that before. That in itself is encouraging. Thank you for sharing this.

  6. By way of asking how people fare when their first illness with pain is NOT fibro or ME/CFS…& if they can differentiate…here’s my contribution on pain:
    I can’t tell the difference in pain from FMS v. ME/CFS.
    I can tell the difference between those types of pain & that from the arthritis.
    I can sort-of differentiate migraines from headaches that might come from ME/CFS & FMS. I think that ME/CFS extends the lifespan of my headaches, sometimes into a couple months of hovering around 3 & spiking to 10 (scale 0-10 pain levels).
    I also have something else adding to pain: uterine fibroids & ovarian cysts that come & go. I’m eligible for a hysterectomy, & when they flare up, they cause both pain & headaches & they eventually trigger flare ups of both ME/CFS & fibro, which makes those items worse in a vicious cycle. I can’t have the surgery because no one could care for my husband while I recuperated, & it might make the fibro pain worse anyway (I know I could control the fibro w/ OTC meds until they did an arthroscopic knee surgery in 2003, after that, I had to have Rx meds available for when it got really bad). Any surgery carries that risk for ME/CFS & fibro.

  7. I was diagnosed with fibromyalgia in 1988. Recently I went back to college to change careers. Imagine my surprise to hear my instructor tell our class of student nurses that fibromyalgia is not a real illness; it is a psychosomatic disorder. I tried to tell her differently, but she would not believe otherwise. So try telling that to my aches, pains, sleep disorders, and chronic fatigue…LOL! I’m now 55 years old. The best treatment I’ve found for myself is light exercise and a balanced diet. The exercise is the last thing a sufferer wants to do. But, I’m telling you it worked for me.

  8. I think that this is an excellent criteria for this disease. I really don’t understand why this isn’t sent out to all doctors all over the world or posted somewhere where a doctor can just look up the criteria for this disease.

    I actually had a doctor say to me that he doesn’t know anything about this disease and doesn’t want to know anything about this disease so I would be better suited to see another GP. Meanwhile finding any available GP in Alberta, Canada is like winning the lottery.

    The part about early detection and treatment is huge as well since most doctors wait and wait and wait to diagnose you and those are months and maybe even years of your life that are totally lost for no reason.
    I like the 4 different stages as well saying that you have to have at least 50% loss of activity in order to qualify because although this causes some people to not get diagnosed as early as they should it gives more support for those who are disabled because of the illness.

    It’s not really fair for people that are literally bed-ridden to be compared to people with some minor aches and pains. Then you get the whole, “Well I know someone with ME/CFS and they still go to work and have a normal life. What is wrong with you?” I find that so annoying!

    On the other hand it kind of scares me (since I am moderate on this scale) that the illness might progress to the point where it might become very severe. Yikes!!!

    I have so much respect for the people that are sicker than I am and are still hanging in there. Just amazing.

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