What is ME/CFS

ME (Myalgic Encephalomyelitis) also known as CFS (Chronic Fatigue Syndrome) or PVFS ( Post Viral Fatigue Syndrome) is a debilitating condition suffered by approximately 240,000 people in the UK alone. It’s characterising features are overwhelming exhaustion of both muscle and mind and malaise accompanied by a wide range of other symptoms.

The primary indicator is a worsening of symptoms following physical or mental exertion, beyond an individual’s tolerance level.

Incidents of ME/CFS is higher in women than men and slightly higher when there is a history of the condition in the family, or past diagnosis of Fibromyalgia, Irritable Bowel Syndrome or mood disorders.

Symptoms experienced can include:

• Severe exhaustion
• Overwhelming fatigue after minimum effort
• Pale facial colour when tired
• Unrefreshed sleep and sleep disturbance
• Headaches
• Painful muscles, weakness and aching joints
• Muscle twitching
• Mood swings
• Fluctuations in body temperature
• Tender swollen lymph glands (neck, armpits and groin)
• Intolerance to alcohol, certain medications and foods such as dairy or wheat
• Sensitivity to chemicals and electricity
• Poor concentration

Digestive problems, including abdominal pain, alternating diarrhea and constipation, nausea, appetite loss, indigestion and excess wind

Diagnostic Criteria

There are no universally agreed diagnostic criteria or tests for ME/CFS. Doctors can only eliminate the possibility of other known conditions with similar symptoms. There is controversy surrounding the current diagnostic criteria though various attempts to define Chronic Fatigue Syndrome have floundered on the vagueness of the word “fatigue”, physically and mentally, from time to time.

The Canadian Clinical Case definition, 2003 has rewritten the guidelines to capture at least what ME is all about. It is not that patients are fatigued. Healthy people get fatigued. Rather the definition specifically selects patients who worsen with exercise. The case definition determines that more prominent symptoms are compulsory and symptoms that share a common region of pathogenesis are grouped together for clarity.

In addition to severe prolonged fatigue, the definition includes the hallmark symptoms of post-exertional malaise and/or fatigue, sleep dysfunction, pain, two or more of the given neurological/cognitive manifestations, and at least one of the given symptoms from two of the categories of autonomic, neuroendocrine and immune manifestations.

Doctors tend to make a diagnosis of ME/CFS by eliminating the possibility of other conditions with similar symptoms, concluding if the results are negative, with a diagnosis of ME/CFS.

Conditions to be eliminated include:

• Addison’s Disease
• Anaemia
• Lime Disease
• Chronic Somatisation Disorder
• Coeliac Disease
• Immuno deficiency
• Malignancy
• Mood Disorders
• Multiple Sclerosis
• Myasthenia Gravis
• Primary sleep disorder
• Rheumatic Disease
• Thyroid Disorder

The process usually takes around six months to complete.

There are differing views on the right diagnostic protocol used to define, diagnose or treat ME/CFS. We have outlined the ones that are known and used throughout the world. Network ME is not a political charity and refuses in anyway to be drawn into a debate concerning the correct procedures for this serious illness. Network ME is solely in existence to provide information and advice and outreach. We do not advocate any one way, but believe that our members have the right to access information on all aspects of this condition, without censorship.

Diagnostic Protocol – Canadian Working Case definition

A patient with ME/CFS will meet the criteria for fatigue, post-exertional malaise and/or fatigue, sleep dysfunction, and pain; have two or more neurological/cognitive manifestations and one or more symptoms from two of the categories of autonomic, neuroendocrine and immune manifestations; and adhere to item 7.

Fatigue: The patient must have a significant degree on new onset. Unexplained, persistent or recurrent physical and mental fatigue that substantially reduces activity level.

Post-Exertional Malaise and/or Fatigue: There is an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability, post-exertional malaise and/or fatigue and/or pain and a tendency for other associated symptoms to worsen. There is a pathological slow recovery period – usually 24 hours or longer.

Sleep Dysfunction: There is Unrefreshed sleep or sleep quantity or rhythm disturbances such as reversed or chaotic diurnal sleep rhythms.

Pain: There is a significant degree of myalgia. Pain can be experienced in the muscles and/or joints, and is often widespread and migratory in nature. Often there are significant headaches or new type, pattern or severity.

Neurological/Cognitive Manifestations: Two or more of the following difficulties should be present: confusion, impairment of concentration and short term memory consolidation, disorientation, difficulty with information processing, categorizing and word retrieval, and perceptual and sensory disturbances – e.g. spatial instability and disorientation and inability to focus vision. Ataxia, muscle weakness and fasciculations are common. There may be overload phenomena: cognitive, sensory – e.g. photophobia and hypersensitivity to noise – and/or emotional overload, which may lead to “crash” and/or anxiety.

At least One symptom from Two of the Following Categories:

Autonomic Manifestations: Orthostatic intolerance – neurally mediated hypotension (NMH), postural orthostatic tachycardia syndrome (POTS), delayed postural hypotension; light-headedness; extreme pallor, nausea and irritable bowel syndrome; urinary frequency and bladder dysfunction; palpitations with or without cardiac arrhythmias; exertional dyspnea.

Neuroendocrine Manifestations: Loss of thermostatic stability – subnormal body temperature and marked diurnal fluctuation, sweating episodes, recurrent feelings of feverishness and cold extremities; intolerance of extremes of heat and cold; marked weight change – anorexia or abnormal appetite; loss of adaptability and worsening of symptoms with stress.

Immune Manifestations: Tender lymph nodes, recurrent sore throat, recurrent flu-like symptoms, general malaise, new sensitivities to food, medications and/or chemicals.

The illness persists for at least six months. It usually has a distinct onset although it may be gradual. Preliminary diagnosis may be possible earlier. Three months is appropriate for children.

To be included, the symptoms must have been begun or have been significantly altered after the onset of this illness. It is unlikely that a patient will suffer from all symptoms in criteria 5 and 6. The disturbances tend to form symptom clusters that may fluctuate and change over time. Children often have numerous prominent symptoms but their order of severity tends to vary from day to day. There is a small number of patients who have no pain or sleep dysfunction, but no other diagnosis fits except ME/CFS. A diagnosis of ME/CFS can be entertained when this group has an infectious illness type onset. Some patients have been unhealthy for other reasons prior to the onset of ME/CFS and lack detectable triggers at onset and/or have more gradual or insidious onset.

Exclusions: Exclude active disease processes that explain most of the major symptoms of fatigue, sleep disturbance, pain and cognitive dysfunction. It is essential to exclude certain diseases, which would be tragic to miss: Addison’s disease, Cushing’s syndrome, Hypothyroidism, Hyperthyroidism, iron deficiency, other treatable forms of anemia, iron overload syndrome, diabetes mellitus, and cancer. It is also essential to exclude treatable sleep disorders such as upper airway resistance syndrome and obstructive or central sleep apnea; rheumatological disorders such as rheumatoid arthritis, lupus, polymyositis and polymyalgia rheumatica; immune disorders such as AIDS; neurological disorders such as multiple sclerosis (MS), Parkinsonism, myasthenia gravis and B12 deficiency; infectious diseases such tuberculosis, chronic hepatitis, Lyme disease, etc; primary psychiatric disorders and substance abuse. Exclusion of other diagnoses, which cannot be reasonably excluded by the patient’s history and physical examination, is achieved by laboratory testing and imaging. Id a potentially confounding medical condition is under control, then the diagnosis of ME/CFS can be entertained if patients meet the criteria otherwise.

Co-Morbid Entities: Fibromyalgia Syndrome (FMS), Myofascial Pain Syndrome (MPS, Temporomandibular Joint Syndrome (TMJ), Irritable Bowel Syndrome (IBS), Interstitial Bladder Syndrome, Raynaud’s Phenomenon, Prolapsed Mitral Valve, Depression, Migraine, Allergies, Multiple Chemical Sensitivities (MCS), Hashimoto’s Thyroiditis, Sicca Syndrome, etc. Such co-morbid entities may occur in the setting of ME/CFS. Others such as IBS may precede the development of ME/CFS by many years, but then become associated with it. The same hold true for migraines and depression. Their association is thus looser than between the symptoms within the syndrome. ME/CFS often closely connect and should be considered to be “overlap syndrome”

Idiopathic Chronic Fatigue: If the patient has unexplained prolonged fatigue (6 months or more) but has insufficient symptoms to meet the criteria for ME/CFS, it should be classified as idiopathic chronic fatigue.

The Oxford Criteria

Chronic Fatigue Syndrome:

1. A syndrome characterised by fatigue as the principle symptom.
2. A syndrome of definite onset that is not life long.
3. The fatigue is severe, disabling and affects physical and mental functioning.
4. The symptom of fatigue should have been present for a minimum of 6 months during which it was present for more than 50% of the time.

Other symptoms may be present, particularly myalgia, mood and sleep disturbance.
Certain patients should be excluded from the definition. They include those with established medical conditions known to produce chronic fatigue (e.g. severe anaemia). Also patients with a current diagnosis of schizophrenia, manic depressive illness, substance abuse, eating disorder or proven organic brain disease. Other psychiatric disorders including depressive illness, anxiety disorders, and hyperventilation syndrome) are not necessarily reasons for exclusion

Post-infectious Fatigue Syndrome (PIFS)

This is a subtype of CFS which either follows an infection or is associated with a current infection (although whether such associated infection is of aetiological significance is a topic for research). To meet research criteria for PIFS patients must:
(i) Fulfil criteria for CFS as defined above, and
(ii) Should also fulfil the following additional criteria:

• There is definite evidence of infection at onset or presentation (a patient’s self0report is unlikely to be sufficiently reliable)
• The syndrome is present for a minimum of 6 months after onset of infection.
• The infection has been corroborated by laboratory evidence.

In reporting studies, it should be clearly stated which of these two syndromes is being studied. The degree of disability should be measured and stated. The criteria and method used to exclude subjects from study must be clearly described and the degree of examination and investigation specified.

All patients should be assessed for associated psychiatric disorder and the results of this assessment reported.

The London Criteria

(Dowsett EG et al. London Criteria for ME In: Report from The National Task Force on Chronic Fatigue Syndrome (CFS), Post Viral Fatigue Syndrome (PVFS), Myalgic Encephalomyelitis (ME) Westcare, 1994 pp96-98

(From: http://www.cfs-news.org/me.html/london940

This description appeared in the National Task Force Report 1994. All three criteria must be present for a diagnosis of ME/PVFS to be made.

1. Exercise-induced fatigue precipitated by trivially small exertion (physical or mental) relative to the patient’s previous exercise tolerance.
2. Impairment of short-term memory and loss of powers of concentration, usually coupled with other neurological and psychological disturbances such as emotional lability, nominal dysphasia, disturbed sleep patterns, disequilibrium or tinnitus.
3. Fluctuation of symptoms should have been present for at least 6 months and should be ongoing.

Although ME/PVFS typically follows an infection, usually a virus illness (which may be subclinical) in a previously fit and active person, it has been observed to be triggered by other factors, such as immunisations, life traumas and exposure to chemicals. Furthermore, in a minority of patients, ME/PVFS has a gradual onset with no apparent triggering factor. For these reasons proof of preceding viral illness is not a prerequisite for diagnosis. Many symptoms are experienced by people suffering from ME/PVFS and in the right symptomatic context they contribute to the validity of the diagnosis. Nevertheless, not all people suffering from ME/PVFS experience all these symptoms and their absence does not exclude the condition.

These are divided into the following categories.

• Bouts of inappropriate night or day-time sweating;
• Raynaud’s phenomenon; postural hypotension;
• Disturbance of bowel motility manifesting as recurrent diarrhea or occasionally constipation ( these symptoms are frequently indistinguishable from those of Irritable Bowel Syndrome);
• Photophobia; blurred vision due to disturbed accommodation;
• Hyperacusis
• Frequency of micturition; nocturia
• Immunological (Symptoms suggesting persistent viral infection):
• Episodes of low grade fever (not exceeding an oral temperature of 38.6C) combined with feeling feverish (i.e. down-regulated ‘thermostat’)
• Sore throat which may be persistent or recurrent (i.e. present for at least one week per month)
• Athralgia (fixed or migratory)

This list is by no means exhaustive. Headaches, nausea and bloating, for instance are common symptoms in many patients in many other disorders. The curious intolerance to alcohol and hypersentivity to drugs are highly specific in this context. It should also be emphasized that the symptoms of ME tend to vary capriciously from hour to hour and day to day. Nevertheless it is absolutely characteristic that they tend to be exacerbated by physical or mental exertion and the association should always be sought whilst taking the history.

Dr Melvin Ramsay

Clinical features of ME were first described by Dr Melvin Ramsay. His description includes the following:

The onset of the disease may be sudden and without apparent cause… but usually there is a history of infection of the upper respiratory tract or, occasionally, the gastrointestinal tract with nausea and/or vomiting. Instead of an uneventful recovery, the patient is dogged by persistent and profound fatigue accompanied by a medley of symptoms such as headache, giddiness, muscle pain, cramps or twitchings, muscle tenderness and weakness, paraethesiae, frequency of micturition, blurred vision and/or diplopia, Hyperacusis, tinnitus and a general feeling of ‘feeling awful’… the phenomenon of muscle fatigability is the dominant and most persistent feature of the disease and in my opinion a diagnosis should never be made without it… if muscle power is found to be satisfactory, a re-examination should be made after exercise; a walk of half a mile is sufficient, as very few ME cases can manage more. Restoration of muscle power can take three to five fays or even longer
(From Post0viral Fatigue Syndrome by A. Melvin Ramsay MA MD)

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