Investigations
1st investigations to order
DePaul symptom questionnaire
Test
A validated screening tool for ME/CFS. A key innovation is that both frequency and severity of ME/CFS symptoms are assessed.[138] The checklist of 54 items provides a thorough evaluation and grading of patient complaints. DePaul symptom questionnaire Opens in new window DePaul scoring sheet Opens in new window
Result
frequency and severity scores are combined to form an overall indicator for each symptom
FBC with WBC differential
Test
Ordered as a baseline investigation to exclude active infection.
Not diagnostic.
Repeat only as clinically indicated.
Result
normal
erythrocyte sedimentation rate
Test
Ordered as a baseline investigation to exclude inflammatory process.
Not diagnostic.
Repeat only as clinically indicated.
Result
normal to low
CRP
Test
Ordered at baseline to exclude inflammatory processes.
Not diagnostic.
Repeat only as clinically indicated.
Result
normal to high-normal
comprehensive metabolic panel
Test
Ordered as a baseline investigation to exclude renal or liver dysfunction, acute infection, or malignancy.
Includes serum electrolytes, urea/creatinine, calcium, phosphorus, aspartate transaminase/alanine transaminase, total protein, albumin, globulin.
Fasting blood sugar assesses for diabetes.
Correction of abnormalities, if found, should be undertaken and symptoms assessed with follow-up.
Repeat only as clinically indicated.
Result
normal
thyroid-stimulating hormone
Test
Ordered as a baseline investigation to exclude hypothyroidism.
Correction of abnormalities, if found, should be undertaken and symptoms assessed with follow-up.
Repeat only as clinically indicated.
Result
normal
antinuclear antibody (ANA), rheumatoid factor
Test
Ordered at baseline to exclude inflammatory markers for connective tissue diseases. ANA has been frequently stated to be positive in chronic fatigue syndrome, so it is prudent to determine whether there is a high titre suggestive of systemic lupus erythematosus, or a low titre. Rheumatoid factor has not been as well defined in prospective fashion.
Not diagnostic.
Repeat only as clinically indicated.
Result
negative
HIV antibody test
Test
To exclude HIV infection.
Result
negative
Investigations to consider
heads-up tilt-table test if symptomatic orthostatic intolerance
Test
Orthostatic tachycardia/hypotension diagnostic for postural orthostatic tachycardia syndrome (POTS).[156]
Result
normal; a sustained heart rate increase of 30 beats per minute or more within 10 minutes of head up tilt (40 bpm age 12-19) in the absence of orthostatic hypotension is evidence of POTS
serum ferritin
Test
Ordered to investigate borderline anaemia that may exacerbate the effects of decreased circulating volume and dysautonomia leading to orthostatic imbalance.
Result
normal
HbA1c
Test
Alternative test to fasting blood sugar to exclude diabetes mellitus.
Result
normal
urine toxicology screen
Test
Ordered as a baseline investigation to exclude drug misuse if this is suspected by history.
Not diagnostic.
Repeat only as clinically indicated.
Result
negative
antibody tests for gluten sensitivity/coeliac disease
Test
If history suggests gluten sensitivity, consider testing for IgG anti-tissue transglutaminase autoantibody, and IgA anti-endomysial autoantibody (note: false-negative results if patient is IgA-deficient).
Not diagnostic.
Repeat only as clinically indicated.
Result
normal
Emerging tests
2-day cardiopulmonary exercise testing
Test
This test is still experimental and should only be used for research purposes. Chronotropic intolerance occurs when the patient is unable to reach their target heart rate.[163] Patients with ME/CFS show a significant decrease in VO₂ max on day 2 that is not found in cardiac, pulmonary, or other conditions. Sensitivity and specificity have not yet been defined to make this a diagnostic test.
Some people report severe exacerbation of post-exertional exhaustion after testing.[109][110][111][164] Exacerbations should be considered diagnostic of post-exertional malaise.
Result
a significant decrease in VO₂ max on the second day's test is presumptive evidence of ME/CFS[162]
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