The Abnormal Perfusion Theory of Fibromyalgia

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This is the theory that the cause of fibromyalgia is the abnormal levels of blood flow to various areas of brain. A study by Guedj et al. using SPECT to measure brain perfusion found that in fibromyalgia some areas of the brain are over-active while others are under-active. Guedj and associates found hyperperfusion of the somatosensory cortex in fibromyalgia and hypoperfusion of the anterior cingulate, posterior cingulate, amygdala, medial frontal gyrus, parahippocampal gyrus and cerebellum. (See Clinical Correlate of Brain SPECT Perfusion, Abnormalities in Fibromyalgia, Eric Guedj et al. J Nucl Med 2008; 49:1798–1803, available in full online at: http://jnm.snmjournals.org/content/49/11/1798.full.pdf+html.)

The theory is open to the criticism that some other even more fundamental factors are responsible for the abnormal perfusion. Perhaps sleep and psychological issues could lead to the various perfusion abnormalities. To address questions such as this there may be a role for longitudinal cases studies whereby a single pain is tracked with a series of sleep and psychological assessment tools as well as a sequence of perfusion studies start¬ing when they a free of fibromyalgia and then following them as they develop the condition.)

The causes for the various areas of over and under-activity are still a matter for speculation.

[Author’s comment: Perhaps the areas of under activity are due to a chronic “burn out” phenomenon. However, to draw such a conclusion would call for careful attention to the effects of duration of illness to see if areas that started off as overactive, be¬came progressively inactivated due to tissue damage to the cortex over time.]

The authors of this study looked for correlations between regional cerebral blood flow and a number of pain-related parameters using the Visual Analog Scale to rate pain intensity, the Tubingen Pain Behavior Scale, and the Questionnaire Douleur deSaint-Antoine Scale). They also looked for correlations between regional cerebral blood flow and disability (as measured by the Fibromyalgia Impact Questionnaire (FIQ) and with anxiety and depression status (as measured by the Hospital Anxiety and Depression scale). Here are their main results:

  • The FIQ total score (which is a measure of fibromyalgia disability) was “positively correlated with bilateral parietal perfusion, including postcentral cortex.” (“These clusters of correlation were included in the areas of significant hyper¬perfusion.”)
  • FIQ total score was “negatively correlated with perfusion of a left anterior temporal cluster, included in the areas of significant hypoperfusions”.

These findings may have implications for insurance cases as when a patient develops fibromyalgia after a car accident and the insurance company is disputing the severity of the illness, not the diagnosis.

(For an image showing the locations of the hypo and hypererperfusion, see Figure 1 of the article which is available online on page 1800.)

The image shows wide areas of bilateral parietal hyperperfusion seen in red. This looks a little like a skull cap which seems to extend into motor areas in front of the parietal areas. The hypoperfusion shown in green is also a large area. It is bilateral and moderately symmetrical. It stands out in the diagrams as green patches in both temporal poles and in medial-basal cortices. For a detailed anatomical explanation of the findings see Table 2 on page 1801.

These results, especially if they are replicated in future studies, could offer treatment biomarkers, especially if methods are found to target areas of hypo and hyper¬perfusion with treatment modalities.