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303 Pain and pain thresholds in Parkinson’s disease
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Poster Presentations / Central Pain / European Journal of Pain 11(S1) (2007) S59–S207
tion acuity was uniformly expressed across all patients, and thermal discrimination was affected regardless of the manifestation of CPSP. However, it was found that heat and cold pain thresholds were more severely affected in the pain group as was the mean side-to-side differences of tactile sensibility. Further correlations indicated that hyperpathia generally coexisted with allodynia and was exclusive to the pain group. These results provide a baseline for the exploration of new methods to predict, assess and treat central neuropathic pain from stroke. doi:10.1016/j.ejpain.2007.03.316
302 STRUCTURAL REMODELLING OF DIFFERENT CLASSES OF PRIMARY AFFERENTS AND DESCENDING PROJECTIONS IN THE DORSAL HORN FOLLOWING SPINAL CORD INJURY A. Kalous *, P.B. Osborne, J.R. Keast Pain Management Research Institute and Kolling Institute, Northern Clinical School, University of Sydney at Royal North Shore Hospital, St. Leonards, NSW, Australia Remodelling in the dorsal horn is a proposed mechanism of spinal cord injury (SCI)-induced neuropathic pain, which is often untreatable. A detailed examination of structural changes of different classes of predominantly small fibre, nociceptive afferents and descending projections after SCI is lacking. Using specific markers of different classes of afferents and descending projections, fibre density in the dorsal horn and marker expression in the dorsal root ganglia (DRG) was analysed after complete transection at spinal level T13 in rats. A transient reduction in the density of CGRP-positive afferents in the dorsal horn at 2 weeks was reversed by 12 weeks, except in the segment closest to injury. Unaltered CGRP expression in the DRG indicated that the changes in fibre density represent degeneration of fibres, followed by regeneration. In contrast, GFRa1-positive afferents were unaffected by transection and many GFRa2-positive afferents were permanently lost from the outer laminae of spinal segments close to the injury. Following SCI there was also a transient up-regulation of GFRa2 expression in deeper laminae of the dorsal horn. The density of descending catecholamine fibres was increased at 2 weeks in the superficial laminae only, and was sustained in the segment closest to injury at 12 weeks. In contrast, descending serotonergic fibres were not altered by transection. These results reveal structural remodelling leading to an altered balance of
afferent inputs and descending modulation that may contribute to neuropathic pain following SCI. doi:10.1016/j.ejpain.2007.03.317
303 PAIN AND PAIN THRESHOLDS IN PARKINSON’S DISEASE S.O. Machnev *, O.S. Levin Russian Medical Academy of Advanced Studying, Moscow, Russia Background. Pain is the important part of Parkinson’s diseases (PD) clinical presentation. Pain is estimated to occur in approximately 50% of patients. However, the mechanisms underlying such painful symptoms, structure of pain syndrome and treatment approaches are poorly investigated. Patients and methods. A total of 68 subjects with PD participated in this study (mean age 58.5 ± 7.3 years, mean duration of disease 4.3 ± 2.6 years, stage of disease according Hoehn–Yahr 2 and 3). To estimate painful sensation we used visual analogue scale. Pain thresholds were estimated by compressing air in cuff with acicular inner surface which consist of several rows of needles (I.A Maseikin, 2005). Comprehensive neuropsychological testing was using for assessment of cognitive and affective impairment. Results. Forty-two patients (61%) had pain. Patients with pain had lower pain thresholds, more severe motor deficit, motor fluctuation, depression and cognitive impairment (especially disexecutive type) compare to patients without pain (p < 0.05). Pain thresholds on more affected side was lower than on less affected side (p < 0.05). There was also negative correlation between pain thresholds, motor deficit and depression. Conclusion. Pain in PD is associated with reduction of pain thresholds. Pain is frequently observed in patients with higher progression tempo of PD and frequently accompanied with affective and cognitive impairment. doi:10.1016/j.ejpain.2007.03.318
304 EFFICACY, BY BASELINE SEVERITY OF ANXIETY SYMPTOMS, OF PREGABALIN FOR TREATING CENTRAL NEUROPATHIC PAIN IN PATIENTS WITH SPINAL CORD INJURY (SCI) T.K. Murphy *,a, P.J. Siddall b, T. Griesing a a
Pfizer Inc., New York, NY, USA Pain Management Research Institute, University of Sydney at Royal North Shore Hospital, Sydney, Australia b
Poster Presentations / Central Pain / European Journal of Pain 11(S1) (2007) S59–S207
tion acuity was uniformly expressed across all patients, and thermal discrimination was affected regardless of the manifestation of CPSP. However, it was found that heat and cold pain thresholds were more severely affected in the pain group as was the mean side-to-side differences of tactile sensibility. Further correlations indicated that hyperpathia generally coexisted with allodynia and was exclusive to the pain group. These results provide a baseline for the exploration of new methods to predict, assess and treat central neuropathic pain from stroke. doi:10.1016/j.ejpain.2007.03.316
302 STRUCTURAL REMODELLING OF DIFFERENT CLASSES OF PRIMARY AFFERENTS AND DESCENDING PROJECTIONS IN THE DORSAL HORN FOLLOWING SPINAL CORD INJURY A. Kalous *, P.B. Osborne, J.R. Keast Pain Management Research Institute and Kolling Institute, Northern Clinical School, University of Sydney at Royal North Shore Hospital, St. Leonards, NSW, Australia Remodelling in the dorsal horn is a proposed mechanism of spinal cord injury (SCI)-induced neuropathic pain, which is often untreatable. A detailed examination of structural changes of different classes of predominantly small fibre, nociceptive afferents and descending projections after SCI is lacking. Using specific markers of different classes of afferents and descending projections, fibre density in the dorsal horn and marker expression in the dorsal root ganglia (DRG) was analysed after complete transection at spinal level T13 in rats. A transient reduction in the density of CGRP-positive afferents in the dorsal horn at 2 weeks was reversed by 12 weeks, except in the segment closest to injury. Unaltered CGRP expression in the DRG indicated that the changes in fibre density represent degeneration of fibres, followed by regeneration. In contrast, GFRa1-positive afferents were unaffected by transection and many GFRa2-positive afferents were permanently lost from the outer laminae of spinal segments close to the injury. Following SCI there was also a transient up-regulation of GFRa2 expression in deeper laminae of the dorsal horn. The density of descending catecholamine fibres was increased at 2 weeks in the superficial laminae only, and was sustained in the segment closest to injury at 12 weeks. In contrast, descending serotonergic fibres were not altered by transection. These results reveal structural remodelling leading to an altered balance of
afferent inputs and descending modulation that may contribute to neuropathic pain following SCI. doi:10.1016/j.ejpain.2007.03.317
303 PAIN AND PAIN THRESHOLDS IN PARKINSON’S DISEASE S.O. Machnev *, O.S. Levin Russian Medical Academy of Advanced Studying, Moscow, Russia Background. Pain is the important part of Parkinson’s diseases (PD) clinical presentation. Pain is estimated to occur in approximately 50% of patients. However, the mechanisms underlying such painful symptoms, structure of pain syndrome and treatment approaches are poorly investigated. Patients and methods. A total of 68 subjects with PD participated in this study (mean age 58.5 ± 7.3 years, mean duration of disease 4.3 ± 2.6 years, stage of disease according Hoehn–Yahr 2 and 3). To estimate painful sensation we used visual analogue scale. Pain thresholds were estimated by compressing air in cuff with acicular inner surface which consist of several rows of needles (I.A Maseikin, 2005). Comprehensive neuropsychological testing was using for assessment of cognitive and affective impairment. Results. Forty-two patients (61%) had pain. Patients with pain had lower pain thresholds, more severe motor deficit, motor fluctuation, depression and cognitive impairment (especially disexecutive type) compare to patients without pain (p < 0.05). Pain thresholds on more affected side was lower than on less affected side (p < 0.05). There was also negative correlation between pain thresholds, motor deficit and depression. Conclusion. Pain in PD is associated with reduction of pain thresholds. Pain is frequently observed in patients with higher progression tempo of PD and frequently accompanied with affective and cognitive impairment. doi:10.1016/j.ejpain.2007.03.318
304 EFFICACY, BY BASELINE SEVERITY OF ANXIETY SYMPTOMS, OF PREGABALIN FOR TREATING CENTRAL NEUROPATHIC PAIN IN PATIENTS WITH SPINAL CORD INJURY (SCI) T.K. Murphy *,a, P.J. Siddall b, T. Griesing a a
Pfizer Inc., New York, NY, USA Pain Management Research Institute, University of Sydney at Royal North Shore Hospital, Sydney, Australia b