There has been a lot of talk about how the symptoms of the PASC (Post-Acute Sequelae of SARS-CoV-2 Infection) patients – hereafter referred to as long-COVID patients – are similar to people with chronic fatigue syndrome (ME/CFS) but, until now, no studies that I’m aware of have compared the two.
Leonard Jason is, not surprisingly, the first to do that. Jason’s been publishing on ME/CFS for decades. His epidemiological studies, way back when, burst the bubble on the idea that ME/CFS was a rare disease mainly affecting yuppies. From pacing to disease burden, to functionality, to tracking infectious mononucleosis patients, Jason’s prodigious output has informed this field in so many ways.
Prior to Jason, for instance, the questions epidemiological studies asked about symptoms were rudimentary; i.e. if they were present or how severe they were. Jason’s DePaul Questionnaire (DSQ) – which was developed for ME/CFS – changed that for good. The DePaul Questionnaire records symptom frequency and severity and uses both scores to come up with a single (0-100) symptom score. It was only after that, that symptoms that are really bothersome in ME/CFS – those that are both frequent and severe – such as post-exertional malaise, were able to stand out.
Now Jason’s reach has extended to long COVID. His new study, “COVID-19 symptoms over time: comparing long-haulers to ME/CFS“, was recently published in “Fatigue: Biomedicine, Health and Behavior” — the Journal, it should be noted, of the International Association for Chronic Fatigue Syndrome/ Myalgic Encephalomyelitis (IACFS/ME). Jason’s certainly primed to study the long haulers. His decade-long studies of the effects of post-infectious illnesses (infectious mononucleosis) means that he’s got a leg up on other researchers. Let’s hope this is just the first of a series of insightful studies on the intersection of long COVID and ME/CFS.
Jason asked almost 300 long-COVID patients about their symptoms at two time points: one a couple of weeks after they became ill, and the other at the present time – and then compared their symptoms to those over 500 people with ME/CFS – most of whom had been ill for over two years – were experiencing. (The ME/CFS symptom data came from the Solve ME/CFS Initiative.)
The average long-COVID patient in the study had been ill for about 22 weeks or about 5 1/2 months (just shy of the 6 month duration needed to meet the criteria for ME/CFS).
Demographically, the two patient sets were quite similar. As with ME/CFS, long COVID appears to mostly strike women (84% female – long COVID; 79% female – ME/CFS). Both sets of patients also tended to be middle-aged (long COVID – 45 years old; ME/CFS – 55 years old).
The symptom pattern was intriguing. At the start of their illness, long-COVID patients reported more severe symptoms than the people with ME/CFS. Over the course of 5 months or so, their symptoms tended to decline a bit. By 5 1/2 months or so, the pattern reversed itself. With the long-COVID patients feeling a bit better, they were not worse off than the really long haulers – the ME/CFS patients.
Importantly, post-exertional malaise (PEM) popped out in both diseases. PEM, it should be noted, is not a common symptom in diseases in general. It’s such an unusual symptom that it didn’t exist as a symptom to assess until chronic fatigue syndrome (ME/CFS) came on the scene.
The Post-Exertional Malaise (PEM) Crunch
While it’s possible that some degree of PEM is present in other illnesses, in no other illnesses has it played such a central role. That is, until now. PEM stood out in both the long-COVID patients and the people with ME/CFS.
Jason’s DePaul Questionnaire separates PEM into six different categories: heavy feeling, mental fatigue, minimum exercise, feeling drained, fatigue and muscle weakness, and provides an average PEM score. With the DePaul Questionnaire’s symptom score of 0-100, compare the average PEM score to those the other main symptom categories.
*There’s also the orthostatic symptom category which went from 46-34-29./ I accidentally transposed the numbers for column above the immune category into the immune category. The correct immune numbers are 44, 20 and 28.
The PEM score is about 20% above other scores in both conditions. Jason’s breakdown of the PEM scores reveals that both diseases were particularly distinguished by high levels of fatigue, problems with minimum exercise and feeling drained (all in the 70s).
Trouble paying attention, unrefreshing sleep, needing to nap, soreness and muscle pain stood out as particularly troublesome symptoms in both patient groups.
Shortness of breath (62) and difficulty breathing (56), on the other hand, stood out in the long-COVID group (62). (Difficulty breathing was not measured in ME/CFS).
Early Long-COVID Symptoms Suggest Ongoing Immune Response Present
The early symptoms of the long-COVID patients suggested their bodies were wrapped up in an ongoing immune response. These symptoms tended to drop dramatically (flu (59-21), sore throats (43-26) lymph nodes (31-19), fever (38-11) high temperature (48-22) over time. So did many of the formerly prominent neuroendocrine symptoms: chills (47-20), night sweats (43-24), hot/cold feelings (50-34).
Other symptom categories dropped but were more distinguished by their consistency over time. Five months or so later, pain had dropped by an average of 5 points or so and was still high (average 44). Similarly, PEM (68-61), sleep (55-48), and gastrointestinal symptoms (27-24) remained mostly steady. Neurocognitive symptoms (difficulty remembering, understanding, talking, etc.) was the only category to worsen (38-39) but only slightly.
Five months later, the core symptoms of ME/CFS (PEM (fatigue), sleep, and cognitive problems) were turning out to be the core symptoms in long COVID as well.
Early Long COVID vs ME/CFS
Three symptom categories distinguished the early long-COVID patients from people with ME/CFS: the high immune, neuroendocrine and orthostatic intolerance scores. Chest pain, irregular heartbeats, shortness of breath, fever, high temperature, night sweats, loss of appetite and weight change were all dramatically higher in the people with long COVID early in their illness. All of these could be associated with the “sickness response”.
As noted above, most of these symptoms declined rather dramatically over time, but a couple – all cardiovascular in nature (chest pain, shortness of breath, irregular heartbeat) remained significantly more troublesome in the long-COVID group
ME/CFS Group vs Long COVID
Whatever hope the long-COVID group could glean from some of the general symptom declines would have been dashed a bit, though, by looking to what might be in store for them in the ME/CFS group. If long COVID does indeed turn out to be ME/CFS, things were mostly not likely to get better, and in some cases might get worse. On the brighter side, things tended not to get much worse over time.
Sleep was worse in the ME/CFS group (ME/CFS / long-COVID at 5 months: 55-48) with unrefreshing sleep (74-62) being particularly problematic. PEM was worse in the ME/CFS patients but just by a bit (65-61). Cognitive problems worsened (46-39) but not dramatically. Immune symptoms were about 40% worse (28-20) but were not a major factor.
A few symptoms stood out. Flu symptoms; night sweats; hot/cold feelings; sensitivity to smells, light and noise; bloating; bladder issues; cold limbs; sore throats; and headaches were clearly much worse in the ME/CFS group. Many other symptoms tended to worsen in the ME/CFS group but many were not major symptoms and didn’t worsen significantly. On the bright side for the long-COVID group, orthostatic symptoms were reduced compared to the ME/CFS group.
Time will tell how this all plays out, but for right now, except for some cardiovascular symptoms that were expected to be heightened in the COVID-19 group, the long-COVID patients over time are looking more and more like people with ME/CFS. The same general symptom theme – PEM, fatigue, cognitive and sleep problems – is dominant in both diseases. PEM – the distinguishing factor in ME/CFS – is also the most prominent and troublesome factor in long COVID as well.
Some of the early symptoms of long COVID distinguished themselves from those found in the ME/CFS group, but they appeared to be mostly with an ongoing immune response, and most declined substantially over time.
The general merging of the symptoms of long COVID and ME/CFS appeared to be reminiscent of the early ME outbreaks. The outbreaks – which tended to be triggered by different pathogens – featured a disparity in symptoms in the early stages of the illness, which tended to resolve to a similar theme of fatigue, PEM, cognitive problems, etc.
If the long-COVID group does turn out to mimic the ME/CFS group, the long-COVID patients might be able to look forward to some reduction in orthostatic symptoms, but overall, some symptom worsening. On the bright side, while their symptoms may get worse, at least in general, they don’t appear likely to get much worse.