[Downloaded free from http://www.indianjpain.org on Wednesday, September 28, 2016, IP: 79.243.240.117]
Editorial
Pulsed radio frequency in pain management Pulsed radiofrequency (PRF) is an available pain treatment modality that, despite a lack of solid evidence, continues to be used among providers. Clinical applications of PRF are increasing and include the treatment of cervical and lumbar facet joint pain, cervical and lumbar radicular pain, sacroiliac joint pain, trigeminal and other neuralgias, myofascial pain, and intra-articular pain.[1] PRF was developed, in part, as a less destructive alternative to conventional RF. Cosman, Sluijter, and Rittman centered on the notion that PRF, in theory, was capable of delivering RF energy sufficient to modulate the electrical field, but insufficient to cause tissue thermocoagulation. Sluijter et al., used Radionics© PRF machine in early 1996 to conduct preliminary clinical trials and wrote the first report of the clinical effects of PRF on dorsal root ganglia in 1998.[2,3] The mechanisms of action of PRF are likely diverse and may include structural cellular damage; neuronal activation; alternations in gene expression; and the global reduction of evoked synaptic activity leading to a decrease in the transmission of pain impulses. All of these could potentially decrease the transmission of pain impulses.[1] PRF uses RF current in short (20 ms), high-voltage bursts; the “silent” phase (480 ms) of PRF allows time for heat elimination, generally keeping the target tissue below 42°C. PRF changes synaptic signaling and causes electroporation. [4] In the current concept, the PRF electrical current reversibly disrupts impulse transmission in small unmyelinated C pain fibers without neuroablation or thermal destruction, while sparing larger nerve fibers that are protected by their myelin sheath.[3] There are few studies to establish efficacy of PRF in various clinical applications, but they are mostly retrospective and with small sample sizes. Access this article online Quick Response Code: Website: www.indianjpain.org
DOI: 10.4103/0970-5333.124581
Indian Journal of Pain | September-December 2013 | Vol 27 | Issue 3
A review of the literature reveals that traditional RF of the medial branches for the treatment of facetogenic pain is well validated. The benchmark for thermal (traditional) lumbar medial branch RF is at least 80% relief of pain for 1 year. The benchmark for the cervical spine is complete (100%) pain relief for 1 year. No studies report complications from PRF in the treatment of facet joint pain.[5,6] Kroll et al.,[7] and Tekin et al.,[8] studied effect of PRF in lumbar facet pain. Both the authors concluded that both RF and PRF are effective and safe in the treatment of facet joint-mediated pain, but that the effects of PRF are not as durable. Various retrospective studies include PRF in the treatment of cervical and lumbar facet joint pain.[9] The use of PRF for facet joint pain seems to be a safer treatment option. However, the magnitude and duration of effect seem to be less than that of conventional RF. Future randomized controlled studies should pay particular attention to include both short-term (less than 6 months) and long-term (6-12 months) follow-up intervals to establish the true efficacy of PRF in treating facet jointmediated pain. Despite the aforementioned studies, there remains a lack of level 1 or 2 evidence showing efficacy of PRF for facet-medicated pain.[1] Teixeira and Sluijter [10] treated eight patients with intradiscal PRF who were suspected as discogenic low back pain. There was a significant decrease in pain scores after 3 months. Uematsu et al.,[11] first applied RF current to the sensory spinal nerve roots. Both cervical and lumbar dorsal root ganglion (DRG)-directed RF application are reviewed by Malik and Benzon.[12] A unique transfacet joint approach to successful PRF of the L5 DRG in a patient with lumbar radiculopathy secondary to foraminal stenosis by Abejon et al.,[13] also has been described. Sluijter et al.,[3] Munglani,[14] Teixeira et al.,[15] van Zundert et al.[16] and Simopoulos et al.,[17] studied the application of PRF for radicular pain. In summary, evidence suggests that PRF for the treatment of both cervical and lumbar radicular pain is beneficial. No complications were noted and decent response rates (50-70%) were noted until about 2-4 months after treatment.[1] Use of PRF in sacroiliac joint pain by Vallejo et al.,[18] showed good to excellent pain relief. In a systematic 111
[Downloaded free from http://www.indianjpain.org on Wednesday, September 28, 2016, IP: 79.243.240.117]
Das and Dey: Pulsed radio frequency in pain management
review of therapeutic sacroiliac joint interventions by Hans Hansen et al.,[19] the evidence for PRF was found to be limited (or poor). Van Zundert et al.,[20] reported idiopathic trigeminal neuralgia successfully treated with PRF. Navani et al.,[21] reported a single case of PRF of the greater occipital nerve for treatment of occipital neuralgia. Shah and Racz[22] perfomed bilateral PRF of the sphenopalatine ganglion for headache followed by traumatic brain injury. Martine Dc et al[23] and Cohen and Foster[24] demonstrated that PRF has also some utility in treating inguinal pain. Tamimi et al.,[25] demonstrated percutaneous application of PRF technology to patients with myofascial pain. There has been anecdotal and various reports regarding use of PRF in shoulder pain,[14,26-28] hip pain,[29] post thoracotomy pain,[30] complex regional pain syndrome (CRPS),[31] carpal tunnel syndrome,[32] post amputation,[33] and various neuralgias. I n t h e m a n a ge m e n t o f p a i n , e v i d e n ce - b a s e d recommendations are of great value. Randomized controlled trials may be difficult to execute, and other forms of knowledge, including basic science studies and other clinical trials, are valid sources of data and ought not to be dismissed. Particularly for emerging treatments and when there is a need to palliate pain, evidence-based medicine may provide little resources for the pain medicine practitioner.[1] The WIP recommendations for PRF for various interventions as described as 2C+ and to be considered when conventional management is not effective.[34]
In addition, PRF also may have a number of potential financial advantages over conventional RF.[35] PRF is an emerging technology which is a better option for complicated pain conditions. PRF will be a likely intervention for complicated as well uncomplicated chronic painful conditions as the evidence accumulates and till then let’s keep our fingers crossed.
Gautam Das, Samarjit Dey1 Editor, Indian Journal of Pain, Ex-Chairman: World Institute of Pain Section (India) Director: DARADIA- The Pain Clinic Concord Tower, 2nd Floor, 92/2A Bidhan Nagar Road, Ultadanga, Kolkata - 700 067, West Bengal, 1Department of Anaesthesiology, NEIGRIHMS, Shillong-18, Meghalaya, India Address for correspondence: Dr. Gautam Das, Director: DARADIA- The Pain Clinic Concord Tower, 2nd Floor, 92/2A Bidhan Nagar Road, Ultadanga, Kolkata - 700 067, West Bengal, India. E-mail:
[email protected]
References
Theoretically, PRF with its various characteristics has a better prospect than conventional RF. But, its practical applications with evidences are yet to be established. PRF is an especially favorable intervention in these cases because the inciting event is thought to be a nerve injury, and inflicting further tissue damage is counterintuitive. PRF also appears to be a relatively safe procedure. Unlike conventional RF, which is associated with neuritis-like reactions, motor deficits, and the risk of deafferentation pain, PRF seems to have few side effects; indeed, we failed to find any reports of adverse reactions secondary to PRF.
Hata J, Karimi DP, DeSilva C, et al. Pulsed radiofrequency current in the treatment of Pain. Crit Rev Phys Rehabil Med 2011;23:213-40. 2. Cosman ER. A comment on the history of the pulsed radiofrequency technique for pain therapy. Anesthesiology 2005;103:1312; author reply 1313-4. 3. Sluijter ME, Cosman E, Rittman W, Van Kleef M. The effect of pulsed radiofrequency fields applied to the dorsal root ganglion. Pain Clin 1998;11:109-17. 4. Cosman ER Jr, Cosman ER Sr. Electric and thermal field effects in tissue around radiofrequency electrodes. Pain Med 2005;6:405-24. 5. Bogduk N. Pulsed radiofrequency. Pain Med 2006;7:396-407. 6. Lord SM, Barnsley L, Wallis BJ, McDonald GJ, Bogduk N. Percutaneous radio-frequency neurotomy for chronic cervical zygapophyseal-joint pain. N Engl J Med 1996;335:1721-6. 7. Kroll HR, Kim D, Danic MJ, Sankey SS, Gariwala M, Brown M. A randomized, double-blind, prospective study comparing the efficacy of continuous versus pulsed radiofrequency in the treatment of lumbar facet syndrome. J Clin Anesth 2008;20:534-7. 8. Tekin I, Mirzai H, Ok G, Erbuyun K, Vatansever D. A comparison of conventional and pulsed radiofrequency denervation in the treatment of chronic facet joint pain. Clin J Pain 2007;23:524-9. 9. Mikeladze G, Espinal R, Finnegan R, Routon J, Martin D. Pulsed radiofrequency application in treatment of chronic zygapophyseal joint pain. Spine J 2003;3:360-2. 10. Teixeira A, Sluijter ME. Intradiscal high-voltage, long-duration pulsed radiofrequency for discogenic pain: A preliminary report. Pain Med 2006;7:424-8.
112
Indian Journal of Pain | September-December 2013 | Vol 27 | Issue 3
The recent double-blind study by van Zundert et al.,[16] is a significant advancement in regard of PRF. However, their report, like others, is limited by a relatively small sample size, bringing into question the validity of any conclusions. Double-blind controlled studies are intrinsically difficult in the pain population due to the natural history of pain syndromes and the ethical problems associated with sham trials. Such studies are also troublesome due to the etiological heterogeneity of pain disorders.[35]
1.
[Downloaded free from http://www.indianjpain.org on Wednesday, September 28, 2016, IP: 79.243.240.117]
Das and Dey: Pulsed radio frequency in pain management
11. Uematsu S, Udvarhelyi GB, Benson DW, Siebens AA. Percutaneous radiofrequency rhizotomy. Surg Neurol 1974;2:319-25. 12. Malik K, Benzon HT. Radiofrequency applications to dorsal root ganglia: A literature review. Anesthesiology 2008;109:527-42. 13. Abejon D, Ortego R, Solis R, Alaoui N, del Saz J, del Pozo C. Trans-facet-joint approach to pulsed radiofrequency ablation of the L5 dorsal root ganglion in a patient with degenerative spondylosis and scoliosis. Pain Pract 2008;8:202-5. 14. Munglani R. The longer term effect of pulsed radiofrequency for neuropathic pain. Pain 1999;80:437-9. 15. Teixeira A, Grandinson M, Sluijter ME. Pulsed radiofrequency for radicular pain due to a herniated intervertebral disc--an initial report. Pain Pract 2005;5:111-5. 16. Van Zundert J, Patijn J, Kessels A, Lame I, van Suijlekom H, van Kleef M. Pulsed radiofrequency adjacent to the cervical dorsal root ganglion in chronic cervical radicular pain: A double blind sham controlled randomized clinical trial. Pain 2007;127:173-82. 17. Simopoulos TT, Kraemer J, Nagda JV, Aner M, Bajwa ZH. Response to pulsed and continuous radiofrequency lesioning of the dorsal root ganglion and segmental nerves in patients with chronic lumbar radicular pain. Pain Physician 2008;11:137-44. 18. Vallejo R, Benyamin RM, Kramer J, Stanton G, Joseph NJ. Pulsed radiofrequency denervation for the treatment of sacroiliac joint syndrome. Pain Med 2006;7:429-34. 19. Hansen H, Manchikanti L, Simopoulos TT, Christo PJ, Gupta S, Smith HS, et al. A systematic evaluation of the therapeutic effectiveness of sacroiliac joint interventions. Pain Physician 2012;15:E247-78. 20. Van Zundert J, Brabant S, van de Kelft E, Vercruyssen A, Van Buyten JP. Pulsed radiofrequency treatment of the Gasserian ganglion in patients with idiopathic trigeminal neuralgia. Pain 2003;104:449-52. 21. Navani A, Mahajan G, Kreis P, Fishman SM. A case of pulsed radiofrequency lesioning for occipital neuralgia. Pain Med 2006;7:453-6. 22. Shah RV, Racz GB. Long-term relief of posttraumatic headache by sphenopalatine ganglion pulsed radiofrequency lesioning: A case report. Arch Phys Med Rehabil 2004;85:1013-6. 23. Martin DC. Pulsed radiofrequency application for inguinal herniorraphy pain. Pain Physician 2006;9:271.
24. Cohen SP, Foster A. Pulsed radiofrequency as a treatment for groin pain and orchialgia. Urology 2003;61:645. 25. Tamimi MA, McCeney MH, Krutsch J. A case series of pulsed radiofrequency treatment of myofascial trigger points and scar neuromas. Pain Med 2009;10:1140-3. 26. Rohof OJ. Radiofrequency treatment of peripheral nerves. Pain Pract 2002;2:257-60. 27. Shah RV, Racz GB. Pulsed mode radiofrequency lesioning of the suprascapular nerve for the treatment of chronic shoulder pain. Pain Physician 2003;6:503-6. 28. Liliang PC, Lu K, Liang CL, Tsai YD, Hsieh CH, Chen HJ. Pulsed radiofrequency lesioning of the suprascapular nerve for chronic shoulder pain: A preliminary report. Pain Med 2009;10:70-5. 29. Kawaguchi M, Hashizume K, Iwata T, Furuya H. Percutaneous radiofrequency lesioning of sensory branches of the obturator and femoral nerves for the treatment of hip joint pain. Reg Anesth Pain Med 2001;26:576-81. 30. Cohen SP, Sireci A, Wu CL, Larkin TM, Williams KA, Hurley RW. Pulsed radiofrequency of the dorsal root ganglia is superior to pharmacotherapy or pulsed radiofrequency of the intercostal nerves in the treatment of chronic postsurgical thoracic pain. Pain Physician 2006;9:227-35. 31. Akkoc Y, Uyar M, Oncu J, Ozcan Z, Durmaz B. Complex regional pain syndrome in a patient with spinal cord injury: Management with pulsed radiofrequency lumbar sympatholysis. Spinal Cord 2008;46:82-4. 32. Haider N, Mekasha D, Chiravuri S, Wasserman R. Pulsed radiofrequency of the median nerve under ultrasound guidance. Pain Physician 2007;10:765-70. 33. Ramanavarapu V, Simopoulos TT. Pulsed radiofrequency of lumbar dorsal root ganglia for chronic post-amputation stump pain. Pain Physician 2008;11:561-6. 34. Van Zundert J, Patijn J, Hartrick CT, Lataster A, Huygen FJ, Mekhail N, editors. Evidence-Based Interventional Pain Medicine According to Clinical Diagnoses, 2nd ed. West Susse: Wiley-Blackwell; 2012. 35. Byrd D, Mackey S. Pulsed radiofrequency for chronic pain. Curr Pain Headache Rep 2008;12:37-41.
Indian Journal of Pain | September-December 2013 | Vol 27 | Issue 3
113
Cite this article as: Das G, Dey S. Pulsed radio frequency in pain management. Indian J Pain 2013;27:111-3. Source of Support: Nill, Conflict of Interest: None declared.