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Mirror-image sensory dysfunction in the post-thoracotomy pain syndrome
Abstracts / Scandinavian Journal of Pain 3 (2012) 173–198
F23 Visualization of painful process in peripheral tissue using positron emission tomography and [11 C]-d-deprenyl Mikko Aarnio 1,5 , Lieuwe Appel 2,6 , Mats Fredrikson 3 , Torsten Gordh 1,5,∗ , Olof Wolf 4 , Clas Linnman 3 1
Department of Surgical Sciences, Anesthesiology and Intensive Care Medicine, Uppsala University Hospital, Sweden 2 PET Centre, Department of Medical Imaging, Uppsala University Hospital, Sweden 3 Department of Psychology, Uppsala University, Sweden 4 Department of Surgical Sciences, Orthopaedics, Uppsala University Hospital, Sweden 5 Uppsala Berzelii Center, Uppsala University, Sweden 6 Section of Nuclear Medicine and PET, Department of radiology, Oncology and radiation Sciences, Uppsala University, Sweden Background/aims: An objective correlate of ongoing painful process in peripheral tissue would represent a progress in the analysis of pain. The aim of this study was to investigate if the extent of the injury and inflammation in musculoskeletal injuries can be visualized, quantified and followed over time using positron emission tomography (PET) with the radioligand [11 C]-d-deprenyl. Methods: Eight otherwise healthy patients with unilateral ankle sprain were PET-imaged acutely and followed up twice, first a month and then up to over one year after injury. Results: Acutely [11 C]-d-deprenyl uptake was significantly increased by a factor 10.7 (range 2.9–37.3) in the injury sites as compared to the intact ankle. During healing [11 C]-d-deprenyl uptake was reduced, but not normalized until after 11 months. Conclusions: Patients experiencing persistent pain showed prolonged [11 C]-d-deprenyl uptake in the injury sites. Thus, PET can be used to visualize, quantify and follow painful processes in peripheral tissue. http://dx.doi.org/10.1016/j.sjpain.2012.05.053 F24 Mirror-image sensory dysfunction in the post-thoracotomy pain syndrome Mads U. Werner 1 , Thomas K. Ringsted 2 , Henrik Kehlet 2 , Kim Wildgaard 2,∗ 1
Multidisciplinary Pain Center, Neuroscience Center, Rigshospitalet, Copenhagen University Hospital, Denmark 2 Section of Surgical Pathophysiology, Rigshospitalet, Copenhagen University Hospital, Denmark Background/aims: Mirror-image sensory dysfunction (MISD) has been described in various medical conditions, but has not been systematically characterized following major surgery. Methods: The presence of MISD was evaluated with standardized thermal and mechanical stimuli, in a group of preoperative patients scheduled for thoracotomy (n = 14) and in patients with post-thoracotomy pain syndrome (PTPS = 14). The primary outcome was areas with sensory dysfunction evaluated by dynamic sensory mapping with metal-rollers and a brush. The test procedures were repeated after 2 weeks in PTPS-patients. Results: The preoperative patients all had normal sensory mapping. In all PTPS-patients sensory dysfunction on the surgical side was observed, while in 12/14 patients MISD was demonstrated. In 5/12 patients, the spatial distribution of MISD areas corresponded to the sensory dysfunction on the surgical side. The total areas of sensory dysfunction (median, [25–75% interquartile range]) were Day 1, on the surgical side 500 cm2 (289–636) and on the non-
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surgical side 60 cm2 (0–379 [P < 0.005]), and on Day 2, 355 cm2 (266–697) and 81 cm2 (0–202 379 [P < 0.0002]), respectively. Area of sensory dysfunction on the surgical side, respectively on the nonsurgical side, did not differ significantly between Day 1 and Day 2 (P > 0.5). Conclusion: Mirror-image sensory dysfunction is a prevalent finding in PTPS-patients. The sensory dysfunction does not seem related to the underlying lung neoplasm per se. The study demonstrated a high day-to-day variability both in sensory dysfunction areas in the surgical side and in MISD-areas. The pathophysiological mechanisms behind MISD in chronic post-surgery pain deserve further study. http://dx.doi.org/10.1016/j.sjpain.2012.05.054 F25 Genetic variation in opioid receptor genes and sensitivity to experimental pain in male and female healthy volunteers A.E. Olesen 1,∗ , J. Droney 2,3 , H. Sato 3 , J.R. Ross 2,3 , C. Staahl 1 , T. Andresen 1 , R. Branford 2,3 , J. Riley 2,3 , A.M. Drewes 1 1
Mech-Sense, Aalborg Hospital, Aalborg, Denmark Royal Marsden Hospital NHS Foundation Trust, London, UK 3 Imperial College London, London, UK 2
Background/aims: Pain is a common problem which significantly impacts on quality of life. Clinical pain is complicated to study due to numerous confounding variables. Normal volunteer models use standardised painful stimuli with resulting reduced phenotype variability. Current studies suggest an association between genetic variability and pain sensitivity. Methods: Data from 50 healthy volunteers in three studies of multi-modal, multi-tissue experimental pain stimulation were included. Skin heat, muscle cuff pressure and visceral pressure were analysed. Genetic variants in the genes coding for the mu, delta and kappa opioid receptors (OPRM, OPRD and OPRK) were studied using multivariate regression modelling to investigate association with pain sensitivity. Results: Reproducibility of baseline data for skin heat, muscle cuff pressure and visceral pressure between studies was confirmed (Cronbach’s ˛ > 0.8). Gender differences in pain sensitivity were seen. Females were more sensitive to skin heat and muscle pressure (P = 0.006 and 0.02 respectively). Genetic associations were also found. OPRK was associated with both skin heat pain (P = 0.009) and muscle cuff pain (P = 0.003). Visceral pressure pain was not associated with either gender or genotype. Conclusion: Genetic variations in the kappa opioid receptor appear to mediate different pain modalities. Gender remains an independent predictor of pain sensitivity. http://dx.doi.org/10.1016/j.sjpain.2012.05.055
F23 Visualization of painful process in peripheral tissue using positron emission tomography and [11 C]-d-deprenyl Mikko Aarnio 1,5 , Lieuwe Appel 2,6 , Mats Fredrikson 3 , Torsten Gordh 1,5,∗ , Olof Wolf 4 , Clas Linnman 3 1
Department of Surgical Sciences, Anesthesiology and Intensive Care Medicine, Uppsala University Hospital, Sweden 2 PET Centre, Department of Medical Imaging, Uppsala University Hospital, Sweden 3 Department of Psychology, Uppsala University, Sweden 4 Department of Surgical Sciences, Orthopaedics, Uppsala University Hospital, Sweden 5 Uppsala Berzelii Center, Uppsala University, Sweden 6 Section of Nuclear Medicine and PET, Department of radiology, Oncology and radiation Sciences, Uppsala University, Sweden Background/aims: An objective correlate of ongoing painful process in peripheral tissue would represent a progress in the analysis of pain. The aim of this study was to investigate if the extent of the injury and inflammation in musculoskeletal injuries can be visualized, quantified and followed over time using positron emission tomography (PET) with the radioligand [11 C]-d-deprenyl. Methods: Eight otherwise healthy patients with unilateral ankle sprain were PET-imaged acutely and followed up twice, first a month and then up to over one year after injury. Results: Acutely [11 C]-d-deprenyl uptake was significantly increased by a factor 10.7 (range 2.9–37.3) in the injury sites as compared to the intact ankle. During healing [11 C]-d-deprenyl uptake was reduced, but not normalized until after 11 months. Conclusions: Patients experiencing persistent pain showed prolonged [11 C]-d-deprenyl uptake in the injury sites. Thus, PET can be used to visualize, quantify and follow painful processes in peripheral tissue. http://dx.doi.org/10.1016/j.sjpain.2012.05.053 F24 Mirror-image sensory dysfunction in the post-thoracotomy pain syndrome Mads U. Werner 1 , Thomas K. Ringsted 2 , Henrik Kehlet 2 , Kim Wildgaard 2,∗ 1
Multidisciplinary Pain Center, Neuroscience Center, Rigshospitalet, Copenhagen University Hospital, Denmark 2 Section of Surgical Pathophysiology, Rigshospitalet, Copenhagen University Hospital, Denmark Background/aims: Mirror-image sensory dysfunction (MISD) has been described in various medical conditions, but has not been systematically characterized following major surgery. Methods: The presence of MISD was evaluated with standardized thermal and mechanical stimuli, in a group of preoperative patients scheduled for thoracotomy (n = 14) and in patients with post-thoracotomy pain syndrome (PTPS = 14). The primary outcome was areas with sensory dysfunction evaluated by dynamic sensory mapping with metal-rollers and a brush. The test procedures were repeated after 2 weeks in PTPS-patients. Results: The preoperative patients all had normal sensory mapping. In all PTPS-patients sensory dysfunction on the surgical side was observed, while in 12/14 patients MISD was demonstrated. In 5/12 patients, the spatial distribution of MISD areas corresponded to the sensory dysfunction on the surgical side. The total areas of sensory dysfunction (median, [25–75% interquartile range]) were Day 1, on the surgical side 500 cm2 (289–636) and on the non-
193
surgical side 60 cm2 (0–379 [P < 0.005]), and on Day 2, 355 cm2 (266–697) and 81 cm2 (0–202 379 [P < 0.0002]), respectively. Area of sensory dysfunction on the surgical side, respectively on the nonsurgical side, did not differ significantly between Day 1 and Day 2 (P > 0.5). Conclusion: Mirror-image sensory dysfunction is a prevalent finding in PTPS-patients. The sensory dysfunction does not seem related to the underlying lung neoplasm per se. The study demonstrated a high day-to-day variability both in sensory dysfunction areas in the surgical side and in MISD-areas. The pathophysiological mechanisms behind MISD in chronic post-surgery pain deserve further study. http://dx.doi.org/10.1016/j.sjpain.2012.05.054 F25 Genetic variation in opioid receptor genes and sensitivity to experimental pain in male and female healthy volunteers A.E. Olesen 1,∗ , J. Droney 2,3 , H. Sato 3 , J.R. Ross 2,3 , C. Staahl 1 , T. Andresen 1 , R. Branford 2,3 , J. Riley 2,3 , A.M. Drewes 1 1
Mech-Sense, Aalborg Hospital, Aalborg, Denmark Royal Marsden Hospital NHS Foundation Trust, London, UK 3 Imperial College London, London, UK 2
Background/aims: Pain is a common problem which significantly impacts on quality of life. Clinical pain is complicated to study due to numerous confounding variables. Normal volunteer models use standardised painful stimuli with resulting reduced phenotype variability. Current studies suggest an association between genetic variability and pain sensitivity. Methods: Data from 50 healthy volunteers in three studies of multi-modal, multi-tissue experimental pain stimulation were included. Skin heat, muscle cuff pressure and visceral pressure were analysed. Genetic variants in the genes coding for the mu, delta and kappa opioid receptors (OPRM, OPRD and OPRK) were studied using multivariate regression modelling to investigate association with pain sensitivity. Results: Reproducibility of baseline data for skin heat, muscle cuff pressure and visceral pressure between studies was confirmed (Cronbach’s ˛ > 0.8). Gender differences in pain sensitivity were seen. Females were more sensitive to skin heat and muscle pressure (P = 0.006 and 0.02 respectively). Genetic associations were also found. OPRK was associated with both skin heat pain (P = 0.009) and muscle cuff pain (P = 0.003). Visceral pressure pain was not associated with either gender or genotype. Conclusion: Genetic variations in the kappa opioid receptor appear to mediate different pain modalities. Gender remains an independent predictor of pain sensitivity. http://dx.doi.org/10.1016/j.sjpain.2012.05.055