Fibromyalgia as a disorder of perceptual organization? An analysis of acoustic stimulus processing in patients with widespread pain.

We examined to what extent patients with fibromyalgia differ from painfree control subjects in the perception and processing not only of somatosensory but also of external stimuli. For this purpose the acoustic perception of 30 patients with fibromyalgia was compared with that of 36 generally pain-free age and gender matched subjects. The groups were also controlled for organic disease of pathological dysfunction of the ear and auditory nerves. Thresholds of unpleasantness and hearing thresholds were determined autiometrically for various frequencies. In addition the participants rated their experience of daily noise, vulnerability to acoustic stress, and functional and affective complaints associated with fibromyalgia. As expected the results show reduced unpleasantness thresholds for all frequencies and a nonsymptomatic hearing loss for higher frequencies. The elevated hearing threshold correlated significantly with experience of noise at the place of work, which was also elevated in the fibromyalgia group. Generalized pain had a high impact on the interaction between threshold of unpleasantness and daily noise experience. We interpret the differences in thresholds of hearing and of unpleasantness in patients with fibromyalgia as a form of either preconscious or conscious acts to protect against disturbing stimulation. Our results support the notion of a generalized disturbancy of perceptual thresholds in patients with fibromyalgia not restricted to the perception of pain.