ME/CFS - An Overview of an Underappreciated Disease

foreign hello this is Eric strong from strong medicine and in this installment of my series on underappreciated diseases I'll be discussing myalgic encephalomyelitis also known as chronic fatigue syndrome or collectively as mecfs first what is it an extreme brief mecfs is a chronic often relapsing and remitting syndrome characterized by profound fatigue post-exertion of malaise poor sleep cognitive impairment that is often labeled brain fog and autonomic dysfunction such as orthostatic intolerance mecfs is the prototypical example of a disease belonging in this series because it has a singular combination of five attributes it's relatively common many patients are profoundly affected we have a poor understanding of its pathogenesis it has no diagnostic test and it is poorly covered in medical school curricula if covered at all thus many doctors have little knowledge of its manifestations and treatment and some still Express skepticism over its existence or its potential severity and all of this leaves patients incredibly frustrated I'm going to spend a minute on the varied names of this condition because just a name can be both confusing and potentially problematic first myalgic encephalomyelitis what exactly does that mean myalgic refers to myalgia which itself refers to pain in the muscles which this disease can certainly cause encephalo refers to the brain myol refers to the spinal cord and itis refers to inflammation so encephalomyelitis means inflammation of the brain and spinal cord but the problem here is that in most patients there's not signs of significant inflammation of the brain at least in any classical sense and no evidence of inflammation of the spinal cord for example the white blood cell count and protein levels in this cerebral spinal fluid of patients are most often normal ESR and CRP are usually normal while some patients report subjective fevers meaning they feel feverish most don't have objectively elevated body temperatures and the disease does not improve with conventional immunosuppression so while there may very well be cytokine dysregulation within the C and S resulting from or resulting in what might be thought of as micro inflammation mecfs does not externally appear to be inflammatory the discordance between the name and clinical presentation might in some cases contribute to misdiagnosis and misunderstanding since Physicians poorly knowledgeable about the disease may be looking for signs that aren't typically there the term myalgic encephalomyelitis itself was coined in 1956 and if you read some of the original case series from that time some of them don't even sound like the same disease that the term is often used to describe today for one thing many of the original patients from these K series recovered relatively quickly and in fact the original name was given to this disease was benign myalgic encephalomyelitis yet I don't think anyone who's diagnosed with this today would characterize it as benign alternatively there is the term chronic fatigue syndrome which was introduced in the 1980s which both removes the implied pathogenesis of inflammation while also highlighting the most prominent symptom for many patients the fatigue unfortunately it has been felt to underemphasize the severity of the condition it also doesn't Encompass the breadth of symptoms patients experience particularly post-exertion malaise which is a much more specific feature of the disease than fatigue one researcher compared renaming me to chronic fatigue syndrome as if the severe life-threatening lung disease COPD was renamed chronic cough syndrome to address these issues in 2015 the United States's Institute of medicine recommended renaming the disease systemic exertion intolerance disease or seid however there is concern that the iom did not sufficiently vet The Proposal with Patient Advocates within the mecfs community who felt that this term did not really capture their experience with a condition as a result seid has not been widely adopted in practice that is it's rarely used outside of the medical literature at the time of this filming the combined term mecfs is the one most commonly used by patients in English-speaking countries so I'll be predominantly using that term for the rest of this video but this disagreement over the condition's proper name is actually about more than just semantics which I will come back to when discussing its diagnosis before that let's discuss the clinical presentation among its clinical features one that is nearly Universal is post-exertional malaise meaning a general of achiness and hard to describe physical discomfort throughout the body that occurs shortly but not always immediately after physical or mental exertion the degree of exertion necessary to trigger pem is individual specific and can be surprisingly modest another nearly Universal feature is cognitive impairment which most often manifests as poor short-term memory difficulty concentrating or decreased information processing speed common features include profound fatigue poor quality or unrefreshing sleep headaches recurrent sore throat tender cervical and axillary lymph nodes myalgias and arthralgias which refers to pain in the muscle and Joints respectively but without overt evidence of inflammation hypersensitivity to external stimuli such as light sound and smells and autonomic dysfunction the autonomic dysfunction can include orthostatic intolerance similar to pots episodic sweating and intolerance to changes in the environmental temperature less common but well-described symptoms include depression abdominal pain weight loss and subjective fevers the onset of mecfs can be abrupt over several days in which case it is frequently associated with a preceding infection typically a viral type syndrome surgeries and Trauma are less commonly implicated triggers or the onset of symptoms can be gradual over many months in which case a specific trigger may not be identified the severity of symptoms is extremely variable however among patients who have been formally diagnosed the majority are unable to consistently work and approximately 25 percent are functionally homebound the most profoundly affected patients are bed bound and may even require tube feeding for nutrition when it comes to the epidemiology the prevalence of mecfs is unknown due to the varied definitions and diagnostic criteria for the syndrome prevalence estimates literally range three orders of magnitude but most sources cite a prevalence in the general neighborhood of 1 in 200 to 1 in 1000. it most commonly presents in young to middle aged adults and there is an observed female-to-male ratio of about two to three to one interestingly there have been dozens of reports of outbreaks of mecfs like syndromes most numerous in the 1950s one of the most notable such outbreaks affected 160 residents of Lake Tahoe in 1985. excluding covid the most recent such outbreak occurred in Norway in 2004 which was associated with the parasite Giardia which had been spread via a contaminated water supply however it's unclear how many of these outbreaks represent the exact same disease that modern medicine typically considers to be mecfs for example some of the earlier outbreaks were characterized by objective muscle weakness resembling polio and some are characterized by high recovery rates both of which are not typical of what is now called mecfs importantly patients with mecfs are not contagious regarding the pathogenesis it is currently unknown however there is no shortage of theories proposed etiologies typically fall into one of four overlapping categories infections among which the Epstein-Barr virus enteroviruses and SARS Kobe 2 with a virus that causes covid are the most frequently implicated to be clear this does not necessarily mean these patients have chronic ongoing infections with these pathogens but rather that an infection had triggered a change to the immune system that persists well after the virus or bacteria has been eliminated from the body a subset of patients who identify as covid long haulers have syndromes which are clinically indistinguishable from mecfs and which may in fact be the exact same thing which brings us to the next category dysregulation of the immune system decreased function of natural killer cells is one of many observed abnormalities however unlike immune-mediated diseases like lupus or rheumatoid arthritis it is not generally believed that autoantibodies are playing a role in mecfs there have been a variety of observed abnormalities of hormone levels within the hypothalamic pituitary adrenal axis which includes cortisol and there is evidence that mecfs has a genetic predisposition as well the diagnosis of mecfs can be challenging symptoms can seem non-specific aside from the post-exertion of malaise which patients may not spontaneously report if they haven't seen the phenomenon described in words before while there are some physical exam findings consistent with mecfs such as orthostatic vital sign changes and tender lymph nodes the exam in most patients is unremarkable routine lab tests are also usually unremarkable this combination results in most patients having their diagnosis delayed by months or even years and even when the condition is suspected there is currently no confirmatory test or biomarker instead there are numerous competing sets of diagnostic criteria for example here's a summary of the 1988 Ramsay narrative description of Emmy the 1994 fukuda criteria for chronic fatigue syndrome and the 2015 iom criteria for systemic exertion intolerance disease I'm not going to read through them all and in fact there are many more sets of criteria than just these three instead I'm going to show them in a Venn diagram if we make a circle for each of the three disease definitions and map where different symptoms in physical science fall this is what we see cognitive impairment and post-exertional malaise are common to all three but that's it not even fatigue was included in the original description of myalgic encephalomyelitis to me this begs the question are these even the same disease to this diagram one could continue to add in other sets of criteria such as the Canadian consensus criteria or the me International consensus criteria but the underlying question remains I'm a hospitalist and not an me CFS expert but I do wonder if it's possible that classically described me and the more recently defined CFS are in fact clinically similar but yet distinct diseases with overlapping but not identical pathogenesis this may help to explain why Medical Science has made relatively little progress towards understanding or treating this condition or group of conditions because if studies include patients with different diseases caused by different pathological mechanisms they will be necessarily more challenging to identify specific epidemiologic associations or biochemical and immunological abnormalities but as of now most clinicians that is the professionals who are diagnosing and treating these patients approach them as if they are one disease just with many different manifestations and most patients also believe these to be the same disease though they may have very strong opinions on the most appropriate name for it when it comes to the differential diagnosis of mecfs that is the list of alternative explanations that a clinician should consider before making the diagnosis it's relatively long and because mecfs has no confirmatory diagnostic test it is particularly important for these diseases to have been specifically ruled out in some way for some alternative diagnoses they can be ruled out by history alone while for others additional testing may be required this differential includes malignancy fibromyalgia actual chronic infections such as EBV post-treatment Lyme disease syndrome hypothyroidism adrenal insufficiency depression anxiety disorders a primary sleep disorder such as sleep apnea or narcolepsy vasculitis or connective tissue disease such as lupus among many others regarding treatments because we currently have a poor understanding of the disease's pathogenesis there is not disease specific treatments available however an important first step is validation of the patient's experience as most have suffered with long delays in diagnosis and some have heard disbelief in the very existence of their illness education about the disease including what's known versus not known is important as well the term pacing or energy management refers to the identification and avoidance of the individual activity threshold that triggers post-exertional malaise it's also important to address symptoms in comorbid conditions this might include sleep hygiene plus or minus tricyclic antidepressants for patients with prominent sleep-related symptoms neurocognitive therapy and the use of memory aids for patients with prominent cognitive impairments and salt and fluid loading and or fluid cortisone for patients with orthostatic intolerance patients often require In-Home Support handicap placards work or school accommodations and family members and caregivers may require their own support as well cognitive behavioral therapy by a psychiatrist or psychologist is sometimes used to help patients manage symptoms and mentally cope with their illness though this is not without controversy and a recommendation for this may be mistaken by the patient as a suggestion that the illness is primarily psychiatric which is not the case cognitive behavioral therapy is not a cure for mecfs given the lack of disease-specific treatments many other things have been tried but they have been found to be not helpful these are generally not recommended for most patients antibiotics antivirals immunosuppressives including prednisone and restrictive and elimination diets graded exercise therapy is a specific approach to increasing physical activity that was previously touted as beneficial but has since been criticized as potentially harmful and most mecfs experts currently recommend against it last regarding prognosis patients with mecfs can experience relative remissions and improvements in symptoms over time but unfortunately an adventure return to the previous level of function is uncommon

Channel: Strong Medicine

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Length: 16min 36sec (996 seconds)

Published: Sun Apr 02 2023