Symptoms which are experienced in the absence of a clear biomedical diagnosis, after appropriate investigation are commonly labelled as 'functional', A theoretical model encompassing functional pain and conversion disorder within a framework of 'auto- suggestive disorder' provides the starting point for the studies reported here. Direct hypnotic suggestion of increasingly painful heat was used to produce an experience of truly 'functional' pain in a group of highly hypnotisable participants, judged to be similar to an experience of 'real' physically-induced pain. This result was supported using functional imaging, demonstrating similar patterns of neural activation in response to physically-induced and hypnotically-induced pain. This study is the first to demonstrate specific neural activity associated with a functional pain experience in healthy controls. Hypnotic and non-hypnotic suggestion was used to modulate the pain experienced by a group of fibromyalgia patients, a condition considered by many to be a functional disorder. Manipulation of such pain in this way enabled the direct observation of the neural activity underlying fibromyalgia pain, circumventing the 'baseline problem' common to neuroimaging investigations of chronic pain. The results linked specific regional activity in areas of the pain matrix with the modulation of fibromyalgia pain. The hypnotic susceptibility of a cohort of fibromyalgia patients was assessed and compared with a group of control participants. No significant differences in hypnotic susceptibility scores were observed, failing to confirm the auto-suggestive disorder hypothesis that these patients should score higher than controls. The findings presented here do not directly support the classification of functional pain conditions as auto-suggestive disorders. However, they do demonstrate for the first time the neural activity associated with the production of a truly functional pain. They provide support for the existence of a central pattern generator for pain, a mechanism capable of generating the experience of pain in the absence of nociceptive input.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:420631 |
| Date | January 2005 |
| Creators | Whalley, Matthew George |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1446721/ |
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