Diagnosis Part 1
Introduction - what is Myalgic Encephalomyelitis (ME)
Facts about ME
- Myalgic Encephalomyelitis is classified as a neurological disease by the World Health Organisation (WHO) ICD G93.3 and SNOWMED-CT.
- It is characterized by immune, neurological and cardiac dysfunction with severe worsening of symptoms following any exertion. The disease most often manifests post-virally. Myalgic Encephalomyelitis has been associated with antecedent infection, often viral, in up to 80% of cases.
- The cardinal symptom is a pathological low threshold of fatigability that is characterized by an inability to produce sufficient energy on demand. There are measurable, objective, adverse responses to normal exertion, resulting in exhaustion, extreme weakness, exacerbation of symptoms, and a prolonged recovery period.
- It has been reported that patients with ME have impaired oxygen extraction on cardiopulmonary exercise testing in proportion to the severity of their symptoms, with both oxygen extraction and workload being decreased on the second day of 2-day cardiopulmonary exercise testing. This may in part explain the characteristic delay between exertion and post exertion response (PENE) onset in ME, and distinguishes patients from deconditioned and fatigued controls. However, we do not recommend routine exercise testing for patients with ME, given its propensity to generate PENE (also referred to as PEM) and to decrease functional capacity.
- Myalgic Encephalomyelitis (ME) can affect all aspects of life of the individual with ME, as well as their families and carers. It has the worst quality of life score than many other serious illnesses including MS, cancer, stroke, congestive heart failure and Rheumatoid Arthritis.
- Myalgic Encephalomyelitis (ME) is not 'functional' or 'psychiatric'; it is not anxiety or depression; it is not Medically Unexplained Symptoms, Functional Neurological Disorder, an eating disorder or any other psychiatric or psychological labels.
- Myalgic Encephalomyelitis (ME) is a distinct, recognisable disease entity that is not difficult to diagnose and can in fact be diagnosed relatively early in the course of the disease, providing that the doctor has some experience with ME. Diagnosis of ME is based on positive signs and symptoms and is therefore not a diagnosis of exclusion.
- Myalgic Encephalomyelitis (ME) is a serious, biophysical, multisystemic disease; it is not due to malingering. Individuals with ME are neither malingering nor seeking secondary gain. This is reflected in reviews of 1000s of biological scientific papers and articles.
More about Myalgic Encephalomyelitis here
Diagnosis
- taking a detailed medical history to rule out other possible causes of symptoms;
- noting the type and severity of symptoms and other characteristics of the illness;
- noting the type of onset of the symptoms; acute or sudden onset of symptoms is seen in ME though feedback tells us that some people experience gradual onset;
- using one of the best set of international guidelines, e.g., the International Consensus Criteria and International Consensus Primer;
- checking for the cardinal feature, the post exertional response to activity, whether physical, mental or emotional, i.e., Post Exertional Neuro-Immune Exhaustion (PENE).
- the lack of a reliable diagnostic biomarker,
- heterogeneity in clinical presentation across patients that may mimic the presentation of other diseases, and
- suboptimal clinician awareness of the condition.
Early Diagnosis
Early Diagnosis is essential in ME.The aim should be to provide people with an early and accurate diagnosis which will allow patients to receive appropriate treatments in a timely manner, which may lessen the severity and impact.
Early diagnosis should enable a comprehensive plan of individual management to be agreed upon, between the patient and doctor. The management plan should include detaiils about symptom management and symptom relief, which may lessen the severity and impact of the individual's symptoms.
Developing an agreed plan of appropriate management - appropriate to the individual's needs - should prevent harmful approaches occurring, e.g. attempting to ‘work through illness’.
Unfortunately most GPs and doctors are not aware of the importance of this treatment practice in ME. Early and appropriate management helps reduce the risk of a more prolonged and more severe form of the illness occurring.
NB: The 3/6-month waiting period before diagnosis is not required as per the ICC 2011.
Resources for Supporting a Diagnosis of ME
Guidelines, Questionnaires, Tools & More Resources to Assess Symptoms in ME & Severity of Symptoms
Guidelines - International Criteria
For diagnosis and management we suggest that you use the Myalgic Encephalomyelitis International Consensus Criteria (ICC 2011) & the Myalgic Encephalomyelitis Adult & Paediatric International Consensus Primer for Medical Practitioners (ICP 2012), both specifically written about and for ME, designed to assess the unique combination of symptoms and features found in ME.
The Myalgic Encephalomyelitis (ME) International Consensus Criteria (ICC)
Myalgic encephalomyelitis is 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. How is ME Diagnosed The symptoms of ME are numerous and can include but are not limited to the following: |
A patient will meet the criteria for postexertional neuroimmune exhaustion (A), at least one symptom from three neurological impairment categories (B), at least one symptom from three immune/gastro-intestinal/genitourinary impairment categories (C), and at least one symptom from energy metabolism/transport impairments (D). |
A. Postexertional neuroimmune exhaustion (PENE pen’-e): Compulsory |
This cardinal feature is a pathological inability to produce sufficient energy on demand with prominent symptoms primarily in the neuroimmune regions. Characteristics are as follows: |
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. Postexertional symptom exacerbation:e.g.acute flu-like symptoms, pain and worsening of other symptoms. |
3. Postexertional exhaustion may occur immediately after activity or be delayed by hours or days. |
4. Recovery period is prolonged, usually taking 24h 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. |
B. Neurological impairments |
At least one symptom from three of the following four symptom categories |
1. Neurocognitive impairments |
a. Difficulty processing information: slowed thought, impaired concentration e.g. confusion, disorientation, cognitive overload, difficulty with making decisions, slowed speech, acquired or exertional dyslexia |
b. Short-term memory loss:e.g. difficulty remembering what one wanted to say, what one was saying, retrieving words, recalling information, poor working memory |
2. Pain |
a. Headaches:e.g. chronic, generalized headaches often involve aching of the eyes, behind the eyes or back of the head that may be associated with cervical muscle tension; migraine; tension headaches |
b. Significant pain can be experienced in muscles, muscle-tendon junctions, joints, abdomen or chest. It is noninflammatory in nature and often migrates. e.g. generalized hyperalgesia, widespread pain (may meet fibromyalgia criteria), myofascial or radiating pain |
3. Sleep disturbance |
a. Disturbed sleep patterns:e.g. insomnia, prolonged sleep including naps, sleeping most of the day and being awake most of the night, frequent awakenings, awaking much earlier than before illness onset, vivid dreams/nightmares |
b. Unrefreshed sleep:e.g. awaken feeling exhausted regardless of duration of sleep, day-time sleepiness |
4. Neurosensory, perceptual and motor disturbances |
a. Neurosensory and perceptual:e.g. inability to focus vision, sensitivity to light, noise, vibration, odour, taste and touch; impaired depth perception |
b. Motor:e.g. muscle weakness, twitching, poor coordination, feeling unsteady on feet, ataxia |
C. Immune, gastro-intestinal and genitourinary Impairments |
At least one symptom from three of the following five symptom categories |
1. Flu-like symptoms may be recurrent or chronic and typically activate or worsen with exertion.e.g. sore throat, sinusitis, cervical and/or axillary lymph nodes may enlarge or be tender on palpitation |
2. Susceptibility to viral infections with prolonged recovery periods |
3. Gastro-intestinal tract:e.g. nausea, abdominal pain, bloating, irritable bowel syndrome |
4. Genitourinary: e.g. urinary urgency or frequency, nocturia |
5. Sensitivities to food, medications, odours or chemicals |
D. Energy production/transportation impairments: At least one symptom |
1. Cardiovascular:e.g. inability to tolerate an upright position - orthostatic intolerance, neurally mediated hypotension, postural orthostatic tachycardia syndrome, palpitations with or without cardiac arrhythmias, light-headedness/dizziness |
2. Respiratory:e.g. air hunger, laboured breathing, fatigue of chest wall muscles |
3. Loss of thermostatic stability:e.g. subnormal body temperature, marked diurnal fluctuations; sweating episodes, recurrent feelings of feverishness with or without low grade fever, cold extremities |
4. Intolerance of extremes of temperature |
Paediatric considerations |
Symptoms may progress more slowly in children than in teenagers or adults. In addition to postexertional neuroimmune exhaustion, the most prominent symptoms tend to be neurological: headaches, cognitive impairments, and sleep disturbances. |
1. Headaches: Severe or chronic headaches are often debilitating. Migraine may be accompanied by a rapid drop in temperature, shaking, vomiting, diarrhoea and severe weakness. |
2. Neurocognitive impairments: Difficulty focusing eyes and reading are common. Children may become dyslexic, which may only be evident when fatigued. Slow processing of information makes it difficult to follow auditory instructions or take notes. All cognitive impairments worsen with physical or mental exertion. Young people will not be able to maintain a full school programme. |
3. Pain may seem erratic and migrate quickly. Joint hypermobility is common. |
Notes: Fluctuation and severity hierarchy of numerous prominent symptoms tend to vary more rapidly and dramatically than in adults. [Severe ME considerations Severe ME, which includes those with severe, very severe and profound ME, sees patients suffering from a horrendous, disabling form of Myalgic Encephalomyelitis. These patients are isolated/confined to bed due to the severity of their symptoms and disabilities, and are often unable to leave their home even to seek medical care.] |
Myalgic Encephalomyelitis: International Consensus Criteria 2011 |
The Myalgic Encephalomyelitis (ME) International Consensus Primer (ICP)
“Patients diagnosed using broader or other criteria for CFS or its hybrids (Oxford, Reeves, London, Fukuda, etc.) should be reassessed with the ICC. Those who fulfill the criteria have ME; those who do not would remain in the more encompassing CFS classification.“
Other Guidelines
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Diagnosis and Management in Young People: A Primer
Questionnaires
Symptom Questionnaire (DePaul Symptom Questionnaire DSQ-2)
PEM Questionnaire (De Paul PEM Questionnaire - DPEMQ)
Post Exertional Neuroimmune Exhaustion (PENE) is a key symptom of Myalgic Encephalomyelitis (ME). PENE is sometimes referred to as PEM. The PEM questionnaire by De Paul, the DPEMQ, is a questionnaire about the post exertional response in ME, the essential criterion for an ME diagnosis.
By answering the questions in the DPEMQ questionnaire, you get an idea of how ‘activity’, i.e., how anything you do physically, cognitively, emotionally, affects you, and what your individual post exertional response is, i.e., what symptoms occur and worsen.
Paediatric Questionnaires
Other Tools To Support Diagnosis
Bells Disability Scale
We tend to refer to the different severities of ME as Mild, Moderate, Severe, Very Severe, Profound - we refer to those as general categories which really have ranges within themselves ie Mild has its own range, as does Moderate and so on.
A good scale that could be used along with these categories to determine near exact range is the Bells Disability Scale. Different people suffer in different ways but this scale gives an idea of the level of disability.
• It can be used by both Patient and Doctor to monitor progress/relapses of ME over time.
% Description
100 No symptoms at rest; no symptoms with exercise; normal overall activity level; able to work fulltime without difficulty.
90 No symptoms at rest; mild symptoms with activity; normal overall activity level; able to work full-time without difficulty.
80 Mild symptoms at rest; symptoms worsened by exertion; minimal activity restriction noted for activities requiring exertion only; able to work full-time with difficulty in jobs requiring exertion.
70 Mild symptoms at rest; some daily activity limitation clearly noted; overall functioning close to 90% of expected except for activities requiring exertion; able to work full-time with difficulty.
60 Mild to moderate symptoms at rest; daily activity limitation clearly noted; overall functioning 70% - 90%; unable to work full-time in jobs requiring physical labour, but able to work full-time in light activities if hours flexible.
50 Moderate symptoms at rest; moderate to severe symptoms with exercise or activity; overall activity level reduced to 70% of expected; unable to perform strenuous duties, but able to perform light duty or desk work 4-5 hours a day, but requires rest periods.
40 Moderate symptoms at rest; moderate to severe symptoms with exercise or activity; overall level reduced to 50% - 70% of expected; not confined to house; unable to perform strenuous duties; able to perform light duty or desk work 3-4 hours a day but requires rest periods.
30 Moderate to severe symptoms at rest; severe symptoms with any exercise; overall activity level reduced to 50% of expected; usually confined to house; unable to perform strenuous tasks; able to perform desk work 2-3 hours a day, but requires rest periods.
20 Moderate to severe symptoms at rest; severe symptoms with any exercise; overall activity level reduced to 30% - 50% of expected; unable to leave house except rarely; confined to bed most of day; unable to concentrate for more than 1 hour a day.
10 Severe symptoms at rest; bedridden the majority of the time; no travel outside of the house; marked cognitive symptoms preventing concentration.
0 Severe symptoms on a continuous basis; bedridden constantly; unable to care for self
Functional Ability
Grip Test
How to Measure Grip Strength:Grip strength is measured using an instrument called a dynamometer. Measure your grip strength with a dynamometer using the following steps:
- Hold your arm with your elbow bent at a 90-degree angle.
- Squeeze the dynamometer as hard as possible.
- Apply grip force in a smooth motion. Avoid jerking.
- Repeat twice more for a total of three times.
- Your grip strength is the average of the three readings.
More Useful Resources for Diagnosis
Patient Doctor Check List Based on the ICC
Simple Questionnaire to determine if the patient meets the ICC Criteria
Differential Diagnoses - Conditions to Rule Out Information Sheet (by ME International US)
Films About ME To Educate & Support a Diagnosis
- Dialogues for ME introduction to ME, link here: Introduction to ME
- Reduced function and the range of symptoms in ME: Patients Accounts - Symptoms
- Post exertional intolerance and the post exertional response, i.e. PENE, also referred to as PEM, the cardinal feature of ME: Understanding Post Exertional Malaise - a Hallmark Feature
- A Brief Guide to Post Exertional Intolerance
More About Diagnosis
Diagnosis in ME using Cardiopulmonary Exercise Testing (CPET)
Diagnosis of Orthostatic Intolerance in ME & the NASA Lean Test
Orthostatic intolerance is common among individuals with ME. Some studies have employed tilt table tests lasting 2–5 min to diagnose one common form of orthostatic intolerance, i.e., postural tachycardia syndrome (POTS).
Symptoms caused by dysautonomia include dizziness, lightheadedness, or fainting (syncope). Vital signs, especially heart rate and blood pressure are monitored as the table slowly raises the patient from lying to nearly standing position.
A tilt table test is generally safe, and complications are rare, but it would only suit some people with mild ME. As with any medical procedure, it carries some risk. Potential complications include: nausea and vomiting, fainting, weakness that can last several hours, and prolonged low blood pressure after the test.
An alternative to Tilt Table Testing is the NASA Lean TestNote! Most people with ME especially those with more severe ME would not be able to do Tilt Table Testing. An alternative test for those who can get out of bed without difficulties, and who are able to sit up for 10 minutes and then also stand for at least 10 minutes is the NASA Lean Test.
For those with more severe ME, doctors can monitor pulse and blood pressure while the patient is standing, and again while lying down. This may need to be repeated several times.
It is known as the ‘poor man’s tilt table test, or more modernly as the NASA Lean Test.
Step By Step Procedure in the NASA Lean Test
Ask the patient to lie down and rest quietly for 15 - 20 minutes.
Then take the first blood pressure and pulse readings and make a note of them.
Ask the patient to sit up for 10 minutes, or as long as they can manage without severe problems, and then take another set of readings and make a note.
Then direct the patient to stand up for 10 minutes, leaning against a wall, but without fidgeting or moving or talking which can affect the result. Then take another set of readings and make a note.
After another 10 minutes of standing and leaning, take the readings again and make a note.
Keep leaning. Do not flex any muscles or talk.
After another ten minutes, take the readings again.
Important Notes for the doctor and patient with regards to the NASA Lean Test!
If at any time the patient starts to feel sweaty or hot or nauseous, the doctor/practitioner needs to take the patient's bp and pulse readings right away and get the patient lying down as soon as possible.
Many patients will not be able to tolerate this much time upright and will need to stop the test partway through. If this happens, take another reading (if possible) and then the patients lies down again.
Failure to stop the tests when the patient becomes severely ill can lead to a loss of consciousness, or severe relapse lasting days, weeks or even months in the very severely affected. Someone should always be standing near the patient to catch them if they fall and serious requests to stop the test must be acted on in a timely manner.
Assessing the readings taken:
For Neurally Mediated Hypotension* (NMH), the patient has to have a 20-25 mm drop in systolic blood pressure (the higher number).
If the patient's pulse suddenly rises at least 30 bpm (beats per minute), then it is likely they have Postural Orthostatic Tachycardia Syndrome* (POTS).
Dr. Rowe believes that they are both really the same thing - with either, if the patient doesn't lie down, they're going to pass out. And the treatment for both is the same.
*Neurally mediated hypotension is also known by the following names: the fainting reflex, neurocardiogenic syncope, vasodepressor syncope, the vaso-vagal reflex, and autonomic dysfunction. Hypotension is the formal medical term for low blood pressure, and syncope is the term for fainting. Neurally mediated hypotension occurs when there is an abnormal reflex interaction between the heart and the brain, both of which usually are structurally normal.
*Postural orthostatic tachycardia syndrome (or POTS) is a condition of orthostatic intolerance in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, often, but not always accompanied by a fall in blood pressure. Patients with POTS also have problems in maintaining homeostasis when changing position ie moving from one chair to another or reaching above their heads.
Symptoms include an abnormally large increase in heart rate upon standing, lightheadedness, extreme fatigue, nausea, headache, chest pain, exercise intolerance and impaired concentration. Patients may exhibit mild hypotension while standing, but most do not experience fainting. POTS patients are usually significantly debilitated by their symptoms.
More Information on the NASA Lean Test
'A Simple Way to Assess Orthostatic Intolerance', an information document by Lucinda Bateman, includes images and pdf copies of instructions for medical providers and patients about how to do the NASA Lean Test, see here.
Common Comorbidities in Myalgic Encephalomyelitis
Further Reading
- Diagnosis of Myalgic Encephalomyelitis (ME) Part 2 here
- Diagnosis of Myalgic Encephalomyelitis (ME) Part 3 here
- Potential Symptoms in ME here
- Diagnostic Overshadowing here
- Communicating with Doctors & other healthcare providers here
- Supporting Individuals with Severe ME in a Hospital or Other Healthcare Setting Information Pack for doctors and other healthcare providers here
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