Unusual symptoms such as digit misidentification and neglect‐like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction.

Cortical reorganisation of sensory, motor and autonomic systems can lead to dysfunctional central integrative control. This may contribute to signs and symptoms of Complex Regional Pain Syndrome (CRPS), including pain. It has been hypothesised that central neuroplastic changes may cause afferent sensory feedback conflicts and produce pain. We investigated autonomic responses produced by ambiguous visual stimuli (AVS) in CRPS, and their relationship to pain. Thirty CRPS patients with upper limb involvement and 30 age and sex matched healthy controls had sympathetic autonomic function assessed using laser Doppler flowmetry of the finger pulp at baseline and while viewing a control figure or AVS. Compared to controls, there were diminished vasoconstrictor responses and a significant difference in the ratio of response between affected and unaffected limbs (symmetry ratio) to a deep breath and viewing AVS. While viewing visual stimuli, 33.5% of patients had asymmetric vasomotor responses and all healthy controls had a homologous symmetric pattern of response. Nineteen (61%) CRPS patients had enhanced pain within seconds of viewing the AVS. All the asymmetric vasomotor responses were in this group, and were not predictable from baseline autonomic function. Ten patients had accompanying dystonic reactions in their affected limb: 50% were in the asymmetric sub-group. In conclusion, there is a group of CRPS patients that demonstrate abnormal pain networks interacting with central somatomotor and autonomic integrational pathways.

(1995). Hypoxia and the Rheumatoid Joint: Immunological and Therapeutic Implications. Scandinavian Journal of Rheumatology: Vol. 24, No. sup101, pp. 163-168.

Allodynia is the perception of pain in response to stimuli that are not normally painful.The management of patients with chronic pain and allodynia is suboptimal, partly because of social stigmatisation.Patients are made to feel that they are malingering or looking for secondary gain.Unfortunately, the legal profession often propagates this myth and the adversarial nature of the courts contributes negatively to the patient's situation.Remarkable recent understandings of profound brain changes occurring in chronic pain patients will challenge the way that such medicolegal cases are decided.This ground-breaking conference related expertise and experiences from patients, clinicians and leading scientists in this field and was the fourth conference in an interdisciplinary series centred around pain and suffering organised by Professor David Blake.

Complex regional pain syndrome (CRPS), a fairly common problem in rheumatological and orthopaedic practice, is an allodynic pain state of uncertain pathology often variably and unpredictably responsive to treatments. Although published diagnostic criteria are available, in the reality of clinical practice these do not appear to encompass the wide variety of symptoms that a patient may present with. This leads to scepticism on the part of the clinician and confusion for the sufferer. This article aims to provide some explanations for an often bewildering clinical picture. We provide a construct for the plethora of symptoms that we have entitled 'the embarrassment of pain perceptions'. With the aid of a case report we examine recent research that suggests how peripherally based symptoms and signs arise from changes within the central nervous system, with particular attention given to the control function of the motor-proprioceptive integrative system. We speculate how these changes within the central nervous system may provide the patient with CRPS the ability to access complex layers of lower level perceptions that are normally suppressed. We propose that such a system may explain some of the clinical puzzlements seen in this condition and suggest that the complexities of CRPS may provide an insight into brain development through evolution, which is a fruitful area for interdisciplinary clinical and scientific research.

Objectives. Contralateral responses to unilateral stimuli have been well described in animal models. These range from central sensitization to peripheral inflammatory responses. Our aim was to test for contralateral responses following unilateral intradermal capsaicin injection in man.Methods. Three groups were investigated. A healthy volunteer group (1) was injected with capsaicin into the volar aspect of one forearm. A group of patients with RA (2) was also injected with capsaicin. A control group of healthy volunteers (3) was not injected with capsaicin. All groups were tested for hyperalgesia and allodynia every 10 min for 1 h following the injection using quantitative sensory testing.Results. A total of 9/14 healthy volunteers (Group 1) and 10/14 patients with RA (Group 2) demonstrated contralateral sensitization that subsided within 1 h following intradermal capsaicin injection. A total of 2/23 control subjects (Group 3) demonstrated positive responses with the monofilaments. The frequency of the contralateral responses in the experimental groups compared with the control group is significant (P < 0.05). The peak hyperalgesia was relatively delayed contralaterally compared with the ipsilateral side (35 min vs 15 min). The area of sensitization, where present, was reduced compared with the ipsilateral side (5-50%).Conclusions. This is the first demonstration of a contralateral response following a unilateral stimulus in man. Bilateral neural pathways mediating contralateral responses may have a role in the pathophysiology of chronically painful or inflammatory diseases and a confounding influence on using the contralateral limb as a control experimentally. We did not find that a systemic inflammatory disease sensitized for this phenomenon.

Background. We have previously demonstrated that CRPS pain can be exacerbated by ambiguous visual stimuli (AVS) (Harrison et al., 2006). We investigated whether this is associated with changes in autonomic function using Laser Doppler Flowmetry. Methods. Ten patients with upper limb CRPS type I who had previously demonstrated exacerbated pain responses to AVS had baseline autonomic responses assessed using a Valsalva manoeuvre (VM), and while viewing AVS. Mean percentage change from baseline blood flow (m%ch), and symmetry ratio (SR) between the limbs were calculated. Results. All patients experienced acute, severe worsening of their CRPS pain within seconds of viewing AVS. Five patients demonstrated asymmetric sympathetic responses (AsyR) induced by viewing AVS and five had symmetric responses (SyR). The affected limb (AL) showed larger responses than the unaffected limb (UL) with the m%ch-AL (±standard error) = 61 (±17), and m%ch-UL = 33 (±15). The patients with SyR to AVS had similar m%ch between limbs, with m%ch-AL = 64 (±16) and m%ch-UL = 56 (±17). The asymmetric group had a high mean SR-AVS = 9.7 (±6.3), whilst the mean SR for AVS in the symmetric group and for VM in both groups approached 1 (mean SR:AVS-SyR = 1.3 (±0.2), mean SR:VM-AsyR = 1.1 (±0.1), mean SR:VM-SyR = 1.2 (±0.2)). Conclusion. Our data indicates that AVS can induce asymmetric autonomic responses.

European Journal of PainVolume 10, Issue S1 p. S121-S121 454 THE VALIDITY OF A QUESTIONNAIRE STUDY OF BIZARRE SYMPTOMS IN COMPLEX REGIONAL PAIN SYNDROME (CRPS) D.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this author D.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this author First published: 13 January 2012 https://doi.org/10.1016/S1090-3801(06)60457-6Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, IssueS1September 2006Pages S121-S121 RelatedInformation

European Journal of PainVolume 10, Issue S1 p. S120a-S120 451 ALTERED LIMB PERCEPTION IN COMPLEX REGIONAL PAIN SYNDROME (CRPS) H.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorC.R. Stevens, C.R. Stevens The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorD.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this author H.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorC.R. Stevens, C.R. Stevens The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorD.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Dept Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this author First published: 13 January 2012 https://doi.org/10.1016/S1090-3801(06)60454-0Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, IssueS1September 2006Pages S120a-S120 RelatedInformation

European Journal of PainVolume 10, Issue S1 p. S120b-S120 452 REFERRED PAIN IN COMPLEX REGIONAL PAIN SYNDROME (CRPS) C.S. McCabe, C.S. McCabe Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.R. Stevens, C.R. Stevens Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this author C.S. McCabe, C.S. McCabe Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorS.J. Harrison, S.J. Harrison Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.R. Stevens, C.R. Stevens Royal National Hospital for Rheumatic Diseases, Bath Department of Medical Sciences, School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this author First published: 13 January 2012 https://doi.org/10.1016/S1090-3801(06)60455-2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, IssueS1September 2006Pages S120b-S120 RelatedInformation

European Journal of PainVolume 10, Issue S1 p. S120c-S121 453 PAINFUL DREAMS IN COMPLEX REGIONAL PAIN SYNDROME (CRPS) S.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Dept of Medical Science, School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Dept of Medical Science, School for Health, University of Bath, Bath, UKSearch for more papers by this author S.J. Harrison, S.J. Harrison The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorJ. Lewis, J. Lewis The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorC.S. McCabe, C.S. McCabe The Royal National Hospital for Rheumatic Diseases, BathSearch for more papers by this authorH.S.L. Jerina, H.S.L. Jerina The Royal National Hospital for Rheumatic Diseases, Bath Dept of Medical Science, School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake The Royal National Hospital for Rheumatic Diseases, Bath Dept of Medical Science, School for Health, University of Bath, Bath, UKSearch for more papers by this author First published: 13 January 2012 https://doi.org/10.1016/S1090-3801(06)60456-4Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, IssueS1September 2006Pages S120c-S121 RelatedInformation

European Journal of PainVolume 10, Issue S1 p. S70a-S70 260 COMPLEX REGIONAL PAIN SYNDROME IS ASSOCIATED WITH VISCERAL DISTURBANCE IN BLADDER AND BOWEL: A HYPOTHESIS H. Cohen, H. Cohen Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this authorJ. Lewis, J. Lewis Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health Professions and Rehabilitation Sciences, University of Southampton, Southampton, UKSearch for more papers by this authorC.S. McCabe, C.S. McCabe Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this author H. Cohen, H. Cohen Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this authorJ. Lewis, J. Lewis Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health Professions and Rehabilitation Sciences, University of Southampton, Southampton, UKSearch for more papers by this authorC.S. McCabe, C.S. McCabe Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this authorD.R. Blake, D.R. Blake Dept of Rheumatology, The Royal National Hospital for Rheumatic Diseases, Bath, UK School for Health, University of Bath, Bath, UKSearch for more papers by this author First published: 13 January 2012 https://doi.org/10.1016/S1090-3801(06)60263-2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, IssueS1September 2006Pages S70a-S70 RelatedInformation