Invited Presentations / Workshop – Specific Diseases 3 / European Journal of Pain 11(S1) (2007) S1–S57
for better preventive strategies since the success of available therapies have been less than promising. doi:10.1016/j.ejpain.2007.03.089
76 EXTENDED DIAGNOSTIC PROCEDURES IN PATIENTS WITH COMPLEX REGIONAL PAIN SYNDROME C. Maier BG Kliniken Bergmannsheil, Ruhr University Bochum, Germany Within the last decade in Germany the number of patients referred with the diagnosis of ‘‘CRPS’’ to the comprehensive pain centers has been escalated, Most of them suffer from painful limb pain, associated with more or less edema and movement/gait disorder. To our experiences, CRPS is the right (or the only one) diagnosis only in 50–60% (in children <10%) of these patients. Some patients suffer from poor diagnosed posttraumatic sequels (for example arthrosis of the wrist/ ankle) and the diagnosis ‘‘CRPS’’ was made notwithstanding the IASP and the recent published criteria was not fulfilled overall. However, in two other groups of patients all typical CRPS symptoms and signs are present: (i) pain mostly after nerve (or joint) injury with distal spread of pain often in combination with vasoconstriction leading leg temperature differences (e.g. sympathetically maintained pain-SMP) or (ii) in patients with long-term immobilisation, limb disuse or gait abnormalities due to severe psychiatric/psychosomatic disorder (for example: adjustment disorder, self-inflicted injury or other psychiatric disorder). The clinical diagnosis is a great challenge, not at least because some of these patients develop a CRPS additionally (some primary), other do not. Many of these are treated without any effect with invasive and potential threatening measures like intrathecal opioid treatment, spinal cord stimulation or neurolytic blocks or are opioid dependent. Therefore extended diagnostic procedures are obviously important. Nevertheless, the accurate clinical (including the analysis of neglect-like syndrome), but also psychological examination remain the most important steps. In some cases with severe, but confusing findings we perform an advanced protocol, including the examination of joint range of motion in general narcosis. The most useful technical method is the three phase bone scan. Its characteristic figures in 3rd phase provide the highest specificity (> as X-ray MRI) and adequate sensitivity for the diagnosis of CRPS, unfortunately only within the first 6–9 month after onset of CRPS. Another new diagnostic approach is the comprehensive PC -assisted 6–8 h evaluation of skin temperature
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changes of the affected and the contra lateral limb during daily activities. Side temperature differences >2– 3 C allow no discrimination of CRPS from SMP and immobilized patients. The most striking issue is the number of short-time changes at both sides (decreased in CRPS) and the frequency of non-synchronic temperature changes (increased only CRPS ). doi:10.1016/j.ejpain.2007.03.090
77 COMPLEX REGIONAL PAIN SYNDROME: NO BRAIN – NO PAIN? C. Maihofner Departments of Neurology and Experimental Pathophysiology, University of Erlangen, Germany Complex regional pain syndromes (CRPS) are characterized by a typical constellation of symptoms: autonomic and inflammatory changes, motor symptoms and sensory disturbances. There is accumulating evidence that the pathophysiology may involve changes within the central nervous system. In this talk a magnetoencephalographic (MEG) study will be presented assessing possible cortical reorganization within the primary somatosensory cortex (S1) in CRPS patients. The distance between the cortical representation of the hand and the lip was markedly decreased on the affected CRPS side compared to the unaffected side. The extent of cortical reorganization was significantly correlated to the magnitude of CRPS pain and mechanical hyperalgesia. In order to investigate whether these S1 changes are reversible and how they change after treatment, we performed a follow up study and traced the somatotopy within the S1 cortex of our patients employing MEG at least one year after therapy. For the whole group, at time of second investigation the distance between cortical representations of digits one and five on the CRPS side increased to a normal size. The reduction of cortical reorganization was predicted by the reduction of pain. Finally, an fMRI study investigating motor dysfunction in CRPS will be presented. Supported by the German Research Network ‘‘Neuropathic Pain Syndromes’’ (German Federal Ministry of Education and Research, BMBF). doi:10.1016/j.ejpain.2007.03.091
78 CRPS – A DISEASE WITH LIMITED EVIDENCEBASED THERAPIES S.N. Raja The Johns Hopkins University, Department of Anesthesiology and Critical Care Medicine, Baltimore, MD, USA