The Parts of ME: Does “Post Exertional Malaise (PEM)” exist in other diseases?


When the National Academy of Medicine (NAM, formerly the Institute of Medicine/IOM) released its recommendations for Systemic Exertion Intolerance Disease (SEID) as a replacement for “ME/CFS,” I saw a lot of people spreading this myth: That “post exertional malaise” (PEM) is what differentiates myalgic encephalomyelitis (M.E.) from other illnesses. This is not true, nor is this what’s explained in the NAM’s report. At most, the report says that the presence of PEM helps distinguish it from other conditions, while it is what best distinguishes “ME/CFS” from idiopathic chronic fatigue. PEM alone is not specific to M.E., Chronic fatigue syndrome (CFS), or SEID, just like unrefreshing sleep is not specific to any one disease.

What distinguishes M.E. from other illnesses is a chronic, severe, measurable loss of sustainable strength on exertion, alongside a detailed history which almost always includes a noticeable infectious onset. (Rarely, some may not realize they’ve been infected, but M.E. is always an acute-onset, acquired infectious disease process.)

The term “postexertional malaise” was first coined in the Fukuda definition for CFS without any explanation as to what it actually meant. As we define post-exertional malaise today, it can mean many things, occur in many different diseases, and is usually described as a worsening of all symptoms in response to activities that were well-tolerated pre-illness, and accompanied by delayed recovery.

“Minimum exercise makes me tired”; “drained after mild activity”; “soreness after non-strenuous activities”; “dead feeling after exercise”; “mentally tired after slightest effort”.

“A few studies that compared ME/CFS with other diseases found that, although PEM was experienced by 19 to 20 percent of subjects with major depressive disorder (Hawk et al., 2006a; Komaroff et al., 1996b) and 52 percent of patients with multiple sclerosis (Komaroff et al., 1996b), it was still much more common in ME/CFS patients than in comparison groups. One study found that 64 percent of patients with major depressive disorder experienced PEM, but the authors did not describe how PEM was assessed (Zhang et al., 2010). As mentioned earlier, these prevalence estimates may vary depending on how PEM was defined and queried for, and thus need to be interpreted with caution”.

Dr. Lucinda Bateman, one of many contributors to the NAM’s paper “Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness,” reminds us of the limitations on PEM research:

“Post Exertional Malaise has basically been compared to healthy controls, but there are really very few studies–not just in this section but in all the other parameters–that compare the symptoms to other chronic illnesses. And that’s really needed so we understand where it fits in. Because I think there are other illnesses where people have a consequence of exercise or being upright, it just isn’t termed in quite that way”.

Even in the case of delayed recovery, this is something Lyme disease can cause: Whereas the T cell function of the immune system in healthy individuals will have returned to normal within 12 to 24 hours after exercise, [T-cell function in people with Lyme disease] will depress for 12 to 24+ hours after exercise” .

I’m offering these references so you can see others talking about PEM in the context of illnesses besides ME or CFS, including a quote by the late Rich Van K. after his own exploration. Read the descriptions below and see if they sound at all familiar to you.

From the Phoenix Rising ME/CFS boards :

“I don’t think that PEM is a classic lyme symptom, although I have been wondering the same myself. I’ve heard it said that it’s not, and that if you’re a lymie with PEM you have a babesia infection. It’s the babesia that causes PEM, I gather probably because your red blood cells can’t transport oxygen efficiently when it’s needed. … Interesting, because I had ‘ME’ diagnosis and suffer from PEM but recently found out it’s actually lyme I have”.

“I wanted to chime in on the Post-Exertional ‘Malaise’ symptom. It is true that it is not necessarily associated with lyme itself. But it is a VERY signature symptom of Babesiosis. I was able to exercise throughout my years of ‘CFS’ (which was episodic). However that changed in ’05 and I started having Post-Exertional ‘Malaise’. I was finally diagnosed as infected with lyme and babesia last year. I can really tell the difference in symptoms. Babesia really makes you feel worse with exercise. Regular antibiotics don’t work against Babesia which is a protozoan like malaria. So someone treated for lyme and not babesia will still have fatigue problems. Most of the people with lyme have more than one infection. Babesia is a very common co-infection”.

“Hi, all. I posed the question to a group that includes quite a few ILADS docs and leaders of Lyme support groups. I got several responses, and the consensus was that PEM/PEF is the norm in ‘chronic Lyme’ patients, though there are some who do not have it. Of course ‘chronic Lyme’ includes the coinfections that are often associated with Lyme disease per se, so it could be due to comorbid Babesiosis. Best regards, Rich”

From the LymeNet support forums: “Disabling fatigue which lasts for days or more occurs after exerting myself in normal physical or mental activities. I know that this is a hallmark of Chronic Fatigue Syndrome, but wondered if it occurs in Lyme”.

Yes it does. I believe Babesia (a common co-infection) can also cause these problems. I think it is not uncommon in chronic infections. Lyme can cause dysautonomia. I think that is a big part of why people have post exertional fatigue. I was diagnosed with CFS and fibromyalgia which turned out to be lyme.

This is a sign of babesiosis which is a coinfection of lyme disease.

“Yes, it does. I don’t know what you consider ‘normal’ physical activities, but with any form of CFS or Lyme, aerobic workouts should not happen, period. High stress situations should also be avoided as much as possible. I’m beginning to form the opinion that there are two kinds of Chronic Fatigue Syndrome: Diagnosed Lyme and Undiagnosed Lyme. All the other viruses and coinfections tag along for the ride.”

“Q: Can Lyme Disease cause Post-Exertional Malaise? Absolutely. First, it’s very serious toxic infection. That’s a huge ‘Bingo’ right there. Huge. Infection causes fatigue. Many other reasons are given above and also see the links here for MITOCHONDRIAL dysfunction…”

Post exertional malaise: Prior to treatment and during the beginning of treatment I had it BAD BAD BAD!!! Now I can do a bit more but there are still days when I lie down after doing some things and have malaise…[b]ut prior to treatment–GOSH!! it was so bad I’d just whimper. So I think with treatment some of this will let up for you. It’s so awful and confusing. And like others I had the stupid fibromyalgia diagnoses and even Parkinsons.

Both Lyme disease and Babesiosis rates are rising rapidly, with Lyme in specific infecting 300,000 new people in the US alone–a number the CDC admits is ten times what they originally predicted; it is one of the fastest spreading infectious diseases in both the US and Western Europe, and it is the fastest growing vector-borne infectious disease in the United States. In some places the rates of babesiosis have also increased tenfold , even though you don’t need a tick bite to contract it: Babesia has been the number one transfusion-transmitted infection in the US for years, and may account for many transfusion-related cases of “M.E.”

Fewer than 50% of people with Lyme disease recall a tick bite, fewer than 50% of those people recall a rash, and if you think testing is good enough, you’re absolutely wrong: The ELISA test has only a 50-65% detection rate and Western Blots have been shown to miss almost 1 out of every 3 cases (later proven by culture). For these reasons, Lyme disease can be a clinical diagnosis, where a positive test is not required in order to begin a trial treatment if there is a high likelihood of infection, such as the presence of the “bull’s-eye rash” or other classic symptoms in an endemic region. Some physicians will use antibiotics to stimulate the immune system, counteracting the bacteria’s immunosuppressive defenses and causing tests to become positive if Borrelia burgdorferi is present; this technique is known as an “antibiotic pulse.”

In the UK, Lyme diseases cases are “surging,” already double from 2004, and in England, there were already 111% more cases of Lyme disease in just the first nine months of 2015 than all of 2014 combined. Lyme is also the most common tick-borne disease in Germany, where very conservative estimates suggest 60,000 new cases per year. Despite over 1,000 cases reported in over 400 locations, officials in Australia have yet to alert the public or even admit the disease has spread to their country; 55% of respondents to a 2012 survey by the Lyme Disease Association of Australia were co-infected with babesia.

Worldwide, most people with Lyme disease suffer from coinfections, things like babesiosis that may also be vector-borne (ticks, mosquitoes, biting flies, fleas, even lice) and complicate treatment and recovery. Dr. Carsten Nicolaus, ILADS member (International Lyme and Associated Diseases Society) and Medical and Executive Director of the BCA Clinic in Germany, says 90% of the patients that visit him have co-infections, the most common of which are Bartonella (~40%) and Anaplasmosis/Human Granulocytic Ehrlichiosis (~30%). As is typical, his patients regularly present with other infections such as Chlamydia pneumoniae, Mycoplasma pneumoniae, EBV, and CMV (20), the latter of which are well-known to cause substantially worsened symptoms after exertion.

Someone studying or otherwise trying to help people with ME and CFS cannot afford to dismiss the severity and pertinence of this information. We might be fighting an uphill battle, but researchers in particular cannot afford to not understand something that shares so many symptoms with the illnesses they are studying. How much further could we advance if an ILADS physician were a consultant on all major CFS research? And without comparison studies, how do we really know someone with chronic Lyme disease, babesiosis, EBV, CMV, similar chronic relapsing infections, or other diseases that impair the mitochondria, wouldn’t give similar or even the same results as “ME/CFS” patients if they were subjected to the two-day cardiopulmonary exercise tests, tests which claim to identify a type of PEM “unique” to “ME/CFS”?

Right now, quite simply, we don’t know. What we do know, and what I hope I’ve demonstrated, is that post exertional malaise is not solely associated with chronic fatigue syndrome, or myalgic encephalomyelitis.


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