Fibromyalgia pain and its modulation by hypnotic and non-hypnotic suggestion: an fMRI analysis

The neuropsychological status of pain conditions such as fibromyalgia, commonly categorized as 'psychosomatic' or 'functional' disorders, remains controversial. Activation of brain structures dependent upon subjective alterations of fibromyalgia pain experience could provide an insight into the underlying neuropsychological processes. Suggestion following a hypnotic induction can readily modulate the subjective experience of pain. It is unclear whether suggestion without hypnosis is equally effective. To explore these and related questions, suggestions following a hypnotic induction and the same suggestions without a hypnotic induction were used during functional magnetic resonance imaging to increase and decrease the subjective experience of fibromyalgia pain. Suggestion in both conditions resulted in significant changes in reported pain experience, although patients claimed significantly more control over their pain and reported greater pain reduction when hypnotised. Activation of the midbrain, cerebellum, thalamus, and midcingulate, primary and secondary sensory, inferior parietal, insula and prefrontal cortices correlated with reported changes in pain with hypnotic and non-hypnotic suggestion. These activations were of greater magnitude, however, when suggestions followed a hypnotic induction in the cerebellum, anterior midcingulate cortex, anterior and posterior insula and the inferior parietal cortex. Our results thus provide evidence for the greater efficacy of suggestion following a hypnotic induction. They also indicate direct involvement of a network of areas widely associated with the pain 'neuromatrix' in fibromyalgia pain experience. These findings extend beyond the general proposal of a neural network for pain by providing direct evidence that regions involved in pain experience are actively involved in the generation of fibromyalgia pain.