FIBROMYALGIA TESTS

SUMMARY A number of clinical and investigational abnormalities can be used to validate the presence of FibroMyalgia Syndrome (FMS).  Physical examination will reveal abnormalities beyond tenderness of tender points.  Chemical, antibody, hormonal and blood cell changes can be demonstrated.  There are changes in the electrical activity in muscles and brain.  Diagnostic imaging can illustrate alterations in the brain's processing of sensation and pain. 

Traumatic Causation of FibroMyalgia Syndrome (FMS) is a central medicolegal issue in Personal Injury litigation.  Even when that issue has been resolved, the subjective nature of the criteria for FMS and fluctuating tender point counts often lead to major diagnostic disagreements between medical witnesses. 

FMS may be " diagnosed" on clinical criteria and "confirmed" by tests that are chosen to exclude other similar conditions.  For medicolegal purposes however, directed Independent Medical Examination can usefully address some or all of the following abnormalities that are not routinely tested for clinical purposes.    

Clinical

Physical examination will reveal abnormalities beyond tenderness of tender points.  In FMS there is increased skin redness in response to pressure and greater resistance to compression of some muscles¹

As well as undue tenderness to pressure, there is increased sensitivity to other painful stimulation - to cold and heat all over the body² and to electrical stimulation at tender points ³. 

Chemical

Pain amplifiers are increased

The CerebroSpinal Fluid (CSF) that bathes the brain and spinal cord has greater than normal concentration of Substance P,⁴ in the order of a 3-fold increase⁵.  Substance P normally alerts nerve cells in the spinal cord to incoming pain signals^6,7. There is preliminary evidence that Substance P is also more abundant in the afferent (sensory) nerves of FMS sufferers⁸.  

Pain suppressors are decreased

Antibodies to the neurotransmitter Serotonin are 4 times as common⁹.  The natural painkiller beta-endorphin is significantly depleted in the peripheral blood mononuclear cells of FMS compared with non-sufferers and those with Depressive Disorder ¹⁰.  

Bodily defences are altered

The body's production of stress hormones is reduced¹¹.  The deepest stage (four) of sleep is disturbed¹² and this is the stage in which most Growth Hormone (GH) is produced by the body. GH is necessary for the repair and maintenance of healthy muscles, and its production may be diminished in FMS.^{13, 14} 

Natural Killer Cells (T lymphocytes) in the blood are reduced in numbers¹⁵ and some cytokines are produced in increased amounts¹⁶. 

Electrical

There are changes in the electrical activity in muscles and brain.  ElectroMyoGraphy (EMG), recording of the electrical activity in muscles) in tender areas may show that some muscle fibres are in a state of continuous contraction¹⁷.  In the region of tender points there is also greater electrical activity in some muscles that are not involved in the particular movement¹⁸.  

As well as disturbance of stage (four) sleep¹⁹ ElectroEncephaloGraphy (EEG) shows an increased amount of alpha-wave non-Rapid Eye Movement (Non-REM, non-dreaming) sleep²⁰ and the sleep cycle is disorganised²¹. When sufferers are awake, painful stimulation causes larger brainwaves (Evoked Potentials) than normal²².

Diagnostic Imaging

Diagnostic imaging can illustrate alterations in the brain's processing of sensation and pain.  Functional Magnetic Resonance Imaging (fMRI) distinguishes FMS patients from normal²³.  During light thumbnail pressure that is painful only for sufferers, fMRI changes are more widespread in the brain than normal.  For thumbnail pressure that anyone would experience as painful, FMS patients have fMRI activity in anatomically different regions of the brain. 

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