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58 INFLUENCES OF DORSAL ROOT GANGLION PULSED RADIOFREQUENCY ON SPINAL CORD
Invited Presentations / Workshop – Assessment And Diagnosis 3 / European Journal of Pain 11(S1) (2007) S1–S57
57 A CLINICIAN’S PERSPECTIVE ON INTERVENTIONAL PAIN MANAGEMENT IN NEUP: WHAT ACTUALLY WORKS? J.-P. Van Buyten AZ Nicolaas, Campus SM, St. Niklaas, Belgium Chronic neuropathic pain can be difficult to treat, especially when patients become refractory to pharmacology. Despite the availability of new drugs, less than 50% of patients achieve significant benefit with medical treatment, while 70% of patients with failed back surgery syndrome (FBSS) receive inadequate pain relief after repeated back surgery. Finding a solution for such patients presents a therapeutic challenge. Other treatment options are available. Radiofrequency is a target-selective neurolytic technique that has been used clinically for many years, often with good results. However, its success has not been adequately reproduced in good quality, randomized controlled trials (RCTs). The same is true for neural blockade, a diverse group of procedures that can provide localized pain relief. Although clinical experience advocates its use, there is little controlled evidence to confirm its efficacy in neuropathic pain. Intrathecal drug delivery using implantable, programmable pumps is often used to control intractable pain, but uncertainty surrounds its use in pain with a neuropathic component. Neurostimulation can offer an effective alternative. Spinal cord stimulation (SCS) has been used successfully in several neurological disorders, including FBSS and complex regional pain syndrome, where RCTs have demonstrated that SCS is effective compared with reoperation, physical therapy and conventional medical management. Technological developments have also enabled the use of SCS in more difficult indications such as axial low pain. Recently, occipital neurostimulation has shown much promise in the treatment of intractable occipital neuralgia and cervicogenic headache and is worth considering when more conservative treatment and maximal pharmacotherapeutic options have failed. doi:10.1016/j.ejpain.2007.03.071
58 INFLUENCES OF DORSAL ROOT GANGLION PULSED RADIOFREQUENCY ON SPINAL CORD J. Van Zundert *,a,b, B. Joosten b, J. Patijn b, M. Van Kleef b a
Department of Anesthesiology and Multidisciplinary Pain Centre, Ziekenhuis Oost-Limburg, Genk, Belgium b Department of Anesthesiology and Pain Management, University Hospital Maastricht, The Netherlands
S23
Radiofrequency (RF) treatment consists of the application of high frequency current adjacent to the nerve, thus increasing the temperature in the tissue surrounding the electrode tip. The alternative use of RF, called pulsed radiofrequency (PRF), consists in its application in short pulses followed by a silent period allowing for the heat to wash-out. It has been shown that PRF and RF have differential neurobiological effects aside from heat-induced morphological changes. Because pain transmission is modulated in the dorsal gray matter, the early (3 h) and late (7 days) effect in the rat dorsal horn of continuous and PRF current adjacent to the cervical DRG versus sham intervention was investigated. A significant increase of c-Fos expression in the dorsal horn of animals that underwent active intervention compared to the sham-operated controls was observed: both an early increase in c-Fos immunoreactive cells in lamina I and II of the dorsal horn after PRF as well as a late bilateral increase in c-Fos activity in the dorsal horn 7 days after intervention (Van Zundert et al., 2005). The first RCT on pulsed radiofrequency adjacent to the cervical DRG in patients with chronic cervical radicular pain was recently published. At 3 months the pulsed radiofrequency group showed a significantly better outcome with regard to the global perceived effect (>50% improvement) and visual analogue scale (20 point pain reduction). The need for pain medication was significantly reduced in the pulsed radiofrequency group after six months. No complications were observed during the study period (Van Zundert et al., 2007). References Van Zundert, J., de Louw, A. J., Joosten, E. A., Kessels, A. G., Honig, W., Dederen, P. J., et al. (2005). Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn. Anesthesiology, 102, 125–131. Van Zundert, J., Patijn, J., Kessels, A., Lame, I., van Suijlekom, H., & van Kleef, M. (2007). Pulsed radiofrequency adjacent to the cervical dorsal root ganglion in chronic cervical radicular pain: A double blind sham controlled randomized clinical trial. Pain, 127, 173–182. doi:10.1016/j.ejpain.2007.03.072
Workshop – Assessment And Diagnosis 3: NEUROIMAGING AS A DIAGNOSTIC TOOL FOR NEUROPATHIC PAIN – FACT OR FANTASY?
59 Workshop Summary: NEUROIMAGING AS A DIAGNOSTIC TOOL FOR NEUROPATHIC PAIN: FACT OR FANTASY? T.R. To¨lle Neurologishe Klinik, Munich, Germany
57 A CLINICIAN’S PERSPECTIVE ON INTERVENTIONAL PAIN MANAGEMENT IN NEUP: WHAT ACTUALLY WORKS? J.-P. Van Buyten AZ Nicolaas, Campus SM, St. Niklaas, Belgium Chronic neuropathic pain can be difficult to treat, especially when patients become refractory to pharmacology. Despite the availability of new drugs, less than 50% of patients achieve significant benefit with medical treatment, while 70% of patients with failed back surgery syndrome (FBSS) receive inadequate pain relief after repeated back surgery. Finding a solution for such patients presents a therapeutic challenge. Other treatment options are available. Radiofrequency is a target-selective neurolytic technique that has been used clinically for many years, often with good results. However, its success has not been adequately reproduced in good quality, randomized controlled trials (RCTs). The same is true for neural blockade, a diverse group of procedures that can provide localized pain relief. Although clinical experience advocates its use, there is little controlled evidence to confirm its efficacy in neuropathic pain. Intrathecal drug delivery using implantable, programmable pumps is often used to control intractable pain, but uncertainty surrounds its use in pain with a neuropathic component. Neurostimulation can offer an effective alternative. Spinal cord stimulation (SCS) has been used successfully in several neurological disorders, including FBSS and complex regional pain syndrome, where RCTs have demonstrated that SCS is effective compared with reoperation, physical therapy and conventional medical management. Technological developments have also enabled the use of SCS in more difficult indications such as axial low pain. Recently, occipital neurostimulation has shown much promise in the treatment of intractable occipital neuralgia and cervicogenic headache and is worth considering when more conservative treatment and maximal pharmacotherapeutic options have failed. doi:10.1016/j.ejpain.2007.03.071
58 INFLUENCES OF DORSAL ROOT GANGLION PULSED RADIOFREQUENCY ON SPINAL CORD J. Van Zundert *,a,b, B. Joosten b, J. Patijn b, M. Van Kleef b a
Department of Anesthesiology and Multidisciplinary Pain Centre, Ziekenhuis Oost-Limburg, Genk, Belgium b Department of Anesthesiology and Pain Management, University Hospital Maastricht, The Netherlands
S23
Radiofrequency (RF) treatment consists of the application of high frequency current adjacent to the nerve, thus increasing the temperature in the tissue surrounding the electrode tip. The alternative use of RF, called pulsed radiofrequency (PRF), consists in its application in short pulses followed by a silent period allowing for the heat to wash-out. It has been shown that PRF and RF have differential neurobiological effects aside from heat-induced morphological changes. Because pain transmission is modulated in the dorsal gray matter, the early (3 h) and late (7 days) effect in the rat dorsal horn of continuous and PRF current adjacent to the cervical DRG versus sham intervention was investigated. A significant increase of c-Fos expression in the dorsal horn of animals that underwent active intervention compared to the sham-operated controls was observed: both an early increase in c-Fos immunoreactive cells in lamina I and II of the dorsal horn after PRF as well as a late bilateral increase in c-Fos activity in the dorsal horn 7 days after intervention (Van Zundert et al., 2005). The first RCT on pulsed radiofrequency adjacent to the cervical DRG in patients with chronic cervical radicular pain was recently published. At 3 months the pulsed radiofrequency group showed a significantly better outcome with regard to the global perceived effect (>50% improvement) and visual analogue scale (20 point pain reduction). The need for pain medication was significantly reduced in the pulsed radiofrequency group after six months. No complications were observed during the study period (Van Zundert et al., 2007). References Van Zundert, J., de Louw, A. J., Joosten, E. A., Kessels, A. G., Honig, W., Dederen, P. J., et al. (2005). Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn. Anesthesiology, 102, 125–131. Van Zundert, J., Patijn, J., Kessels, A., Lame, I., van Suijlekom, H., & van Kleef, M. (2007). Pulsed radiofrequency adjacent to the cervical dorsal root ganglion in chronic cervical radicular pain: A double blind sham controlled randomized clinical trial. Pain, 127, 173–182. doi:10.1016/j.ejpain.2007.03.072
Workshop – Assessment And Diagnosis 3: NEUROIMAGING AS A DIAGNOSTIC TOOL FOR NEUROPATHIC PAIN – FACT OR FANTASY?
59 Workshop Summary: NEUROIMAGING AS A DIAGNOSTIC TOOL FOR NEUROPATHIC PAIN: FACT OR FANTASY? T.R. To¨lle Neurologishe Klinik, Munich, Germany