Table 4 Further investigations in patients with chronic fatigue of unknown cause
From: Investigating unexplained fatigue in general practice with a particular focus on CFS/ME
Clinical Symptoms/Signs | Additional investigations |
|---|---|
Evidence of Connective Tissue Disease suggested by Raynaud’s phenomenon, mouth ulcers, photosensitive rash, serositis, synovitis, | Anti-nuclear antibody assessment on Hep2 cells, antibodies to ENA and dsDNA. Rheumatoid factor analysis and anti-CCP antibodies |
Muscle tenderness or history of significant exercise related cramps | Creatine Kinase, Lactic dehydrogenase, Liver function tests. Consider EMG and possibly muscle biopsy. Referral for late presenting inherited muscle or glycogen storage diseases. |
Widespread aches and pains especially in older women | Serum calcium and magnesium estimation and DEXA scan for osteoporosis and hyperparathyroidism. Serum immunoglobulin assessment in basic panel will check for myeloma. |
Addison’s/Cushings disease | Synacthen/Dexamethasone suppression test. Random cortisol levels can be reduced in CFS/ME and synacthen is advised. Cortisol awakening response is blunted in CFS/ME and might relate to the exacerbation of fatigue in the morning with difficulty getting up in some patients. |
Tick bites with erythematous rashes and arthralgia and fatigue | Serology for Lyme disease – care with interpretation of results and particularly with results from non-approved laboratories. Lyme disease is rare in the UK especially in areas without deer populations. |
Neurological abnormalities, reduced mental acuity and progressive confusion, leg weakness and bladder/bowel problems | MRI/CTscan of brain for cerebral atrophy, ischaemic areas, plaques of demyelination, tumours in frontal lobes/para-saggital area and possible Arnold Chiara malformation. Consider also neuropsychological testing. |
Intolerance of prolonged standing, recurrent syncope/presyncope, tachycardia within 10Â min of standing or marked hypotension on standing with tachycardia. | Tilt table testing for autonomic dysfunction and further evaluation for postural orthostatic tachycardia |
‘Clicky’ joints with previous dislocation(s), early stretch marks and easy bruising | Consider referral for formal evaluation of an underlying or complicating joint hypermobility syndrome. |
Significant sleep disturbance | Sleep studies. Frequent sleep arousals can cause marked daytime fatigue. |