Pressure and heat pain thresholds and tolerances in patients with fibromyalgia

Objective: Whereas pressure pain thresholds are known to be reduced in patients with fibromyalgia, other sensory modalities have only been scarcely examined. The aim of this study was to investigate pain thresholds and tolerances of mechanical, thermal and electrical stimuli in fibromyalgia patients who did not suffer from major depression or abuse of analgesics. Methods: Twenty-five female fibromyalgia patients were compared with 25 healthy females of the same age. Results: In fibromyalgia patients pressure pain thresholds and tolerances were 33 to 54 percent lower than in the controls at all the measured locations-supraspinatus, lateral epicondyle, finger, tibia and temporal region. Heat pain thresholds in the hand and in the temporal region and heat tolerance in the hand were similar in the two groups, while heat tolerance in the temporal region was marginally reduced in patients [P < 0.05]. Electrical skin pain thresholds were significantly [P < 0.05] reduced in patient. Conclusions: The present findings of a markedly increased sensitivity to pressure, a moderately increased sensitivity to electrical stimuli and a largely normal sensitivity to heat stimuli suggest that fibromyalgia is not simply a condition of multi-modal hyperalgesia.