LETTER
Scrambler Therapy for Chronic Pain To the Editor: We read with interest the article “Predictive Factors Associated With Success and Failure for Calmare (Scrambler) Therapy” by Moon et al.1 First of all we would like to congratulate the authors for undertaking a multicenter study, which is lacking in pain research. The authors report that the overall success rate based on their retrospective multicenter study was 38.1%. Further, they describe the factors that are associated with treatment outcome for Calmare therapy (CT). Lastly, the authors make a strong statement in their conclusion, stating that “Investigators should consider these findings when developing selection criteria in clinical trials designed to determine the efficacy of Calmare therapy.” The intention of this letter is 2-fold—to point out some of the shortcomings of this article and to remind the readers and authors of the correct protocol to be followed for the treatment so that there are no flaws in future studies. In their retrospective study over 5 years (2009 to 2013) of patients from 3 centers, the authors state that the overall outcome for CT was 38.1% and 50.7% for neuropathic pain. This is in contrast to several other studies that reported success rates of >60%.2–4 This discrepancy could be partly explained by the shortcomings we noticed in this particular study as follows: (1) Inclusion criteria: this is a retrospective study whereby the authors included patients with nociceptive and mixed type of pain for which the use of CT was not intended. As such, the authors did not follow the strict criteria for using CT, namely for neuropathic and cancer (with different specific protocols) pain only. (2) Protocol: the number of treatments each patient received in this study is widely variable (3 to 130), with 66.7% having received nonconsecutive treatments. This is clearly a G.M. is the inventor of the technology and has patents and receives honoraria. The other authors have no conflict of interest to declare. DOI: 10.1097/AJP.0000000000000174
Clin J Pain
TO THE
EDITOR
deviation from the protocol as thought and recommended by the inventor, Prof. Marineo. We recommend using the treatment for 10 consecutive days with or without 2day breaks in between. (3) Technique: the authors state, “y. On treatment day 1, the stimulation intensity was increased from a minimum of 10 (the lowest setting, 0.9 V) to a maximum of 70 (the highest setting, 4.9 V) every 515 minutes until the maximum strength tolerated was reached. On subsequent days, treatments were usually started at the highest tolerated setting from the previous session and ramped-up every 515 minutes as tolerated.” On the basis of our experience, the adjustment time should take seconds and not minutes. We believe that the prolonged “adjustment time” (5 to 15 min) could have a paradoxical effect not only by reducing the treatment time but also in inducing acute pain and creating a rebound effect after treatment. In other words, this unorthodox method can diminish the effectiveness of the treatment. (4) Experience/providers: on the basis of our experience and those of others, we can confirm that there is a learning curve with this treatment.5 The authors should note the learning curve in their article, as it could be a factor in their outcome. Further, there is no mention of whether the same operater provided the treatment or not, as operator-dependent variability in such outcome should not be underestimated. The fact that there was a significant difference in outcome between Camp Lejeune and the other 2 centers could be due to not only the type of patients that were treated in those centers, but also possibly by the variation in experience of the operators. (5) Finally, there was no detailed description about the specific types of pain, specific type of medications and doses, and detailed description about pain before and after treatment. It could be that low doses of antidepressants behave differently than maximum doses. In summary, on the basis of the methodology and approach used by the authors, including not following
Volume 31, Number 10, October 2015
the correct protocol, missing details (a lot of unknowns) about the exact type of pathology, medications, and doses at the start of the study and at the end, and the type of comorbidity (ie, coexisting psychiatric condition of which no detail is given), we believe that the results and conclusion of the study should be taken with caution. They achieved welcomed pain relief in 38% of their patients, but might have had double that relief if they had followed the published recommendations. Finally, we can recommend a free software Scrambler Therapy Data Manager (STDM), which can alert the operators in real-time if there is a potential problem in the treatment so that patients can have a better outcome. Salahadin Abdi, MD, PhD* Thomas J. Smith, MD, FACP, FASCO, FAAHPMw Giuseppe Marineo, DScz *Department of Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX wDepartment of Oncology, Johns Hopkins Medical Institutions, Sidney Kimmel Comprehensive Cancer Center Baltimore, MD zDelta Research & Development, Centro Ricerche Bioingegneria Medica, University of Rome “Tor Vergata,” Rome, Italy
REFERENCES 1. Moon JY, Kurihara C, Beckles JP, et al. Predictive factors associated with success and failure for Calmare (Scrambler) therapy: a multi-center analysis. Clin J Pain. 2014. [Epub ahead of print]. 2. Marineo G, Iorno V, Gandini C, et al. Scrambler therapy may relieve chronic neuropathic pain more effectively than guideline-based drug management: results of a pilot, randomized, controlled trial. J Pain Symptom Manage. 2012;43: 87–95. 3. Sabato AF, Marineo G, Gatti A. Scrambler therapy. Minerva Anesthesiol. 2005; 71:479–482. 4. Smith TJ, Coyne PJ, Parker GL, et al. Pilot trial of a patient-specific cutaneous electrostimulation device (MC5-A Calmare) for chemotherapy-induced peripheral neuropathy. J Pain Symptom Manage. 2010;40:883–891. 5. Pachman DR, Weisbrod BL, Seisler DK, et al. Pilot evaluation of scrambler therapy for the treatment of chemotherapy-induced peripheral neuropathy. Support Care Cancer. 2014. [Epub ahead of print].
www.clinicalpain.com |
Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
929
Scrambler Therapy for Chronic Pain To the Editor: We read with interest the article “Predictive Factors Associated With Success and Failure for Calmare (Scrambler) Therapy” by Moon et al.1 First of all we would like to congratulate the authors for undertaking a multicenter study, which is lacking in pain research. The authors report that the overall success rate based on their retrospective multicenter study was 38.1%. Further, they describe the factors that are associated with treatment outcome for Calmare therapy (CT). Lastly, the authors make a strong statement in their conclusion, stating that “Investigators should consider these findings when developing selection criteria in clinical trials designed to determine the efficacy of Calmare therapy.” The intention of this letter is 2-fold—to point out some of the shortcomings of this article and to remind the readers and authors of the correct protocol to be followed for the treatment so that there are no flaws in future studies. In their retrospective study over 5 years (2009 to 2013) of patients from 3 centers, the authors state that the overall outcome for CT was 38.1% and 50.7% for neuropathic pain. This is in contrast to several other studies that reported success rates of >60%.2–4 This discrepancy could be partly explained by the shortcomings we noticed in this particular study as follows: (1) Inclusion criteria: this is a retrospective study whereby the authors included patients with nociceptive and mixed type of pain for which the use of CT was not intended. As such, the authors did not follow the strict criteria for using CT, namely for neuropathic and cancer (with different specific protocols) pain only. (2) Protocol: the number of treatments each patient received in this study is widely variable (3 to 130), with 66.7% having received nonconsecutive treatments. This is clearly a G.M. is the inventor of the technology and has patents and receives honoraria. The other authors have no conflict of interest to declare. DOI: 10.1097/AJP.0000000000000174
Clin J Pain
TO THE
EDITOR
deviation from the protocol as thought and recommended by the inventor, Prof. Marineo. We recommend using the treatment for 10 consecutive days with or without 2day breaks in between. (3) Technique: the authors state, “y. On treatment day 1, the stimulation intensity was increased from a minimum of 10 (the lowest setting, 0.9 V) to a maximum of 70 (the highest setting, 4.9 V) every 515 minutes until the maximum strength tolerated was reached. On subsequent days, treatments were usually started at the highest tolerated setting from the previous session and ramped-up every 515 minutes as tolerated.” On the basis of our experience, the adjustment time should take seconds and not minutes. We believe that the prolonged “adjustment time” (5 to 15 min) could have a paradoxical effect not only by reducing the treatment time but also in inducing acute pain and creating a rebound effect after treatment. In other words, this unorthodox method can diminish the effectiveness of the treatment. (4) Experience/providers: on the basis of our experience and those of others, we can confirm that there is a learning curve with this treatment.5 The authors should note the learning curve in their article, as it could be a factor in their outcome. Further, there is no mention of whether the same operater provided the treatment or not, as operator-dependent variability in such outcome should not be underestimated. The fact that there was a significant difference in outcome between Camp Lejeune and the other 2 centers could be due to not only the type of patients that were treated in those centers, but also possibly by the variation in experience of the operators. (5) Finally, there was no detailed description about the specific types of pain, specific type of medications and doses, and detailed description about pain before and after treatment. It could be that low doses of antidepressants behave differently than maximum doses. In summary, on the basis of the methodology and approach used by the authors, including not following
Volume 31, Number 10, October 2015
the correct protocol, missing details (a lot of unknowns) about the exact type of pathology, medications, and doses at the start of the study and at the end, and the type of comorbidity (ie, coexisting psychiatric condition of which no detail is given), we believe that the results and conclusion of the study should be taken with caution. They achieved welcomed pain relief in 38% of their patients, but might have had double that relief if they had followed the published recommendations. Finally, we can recommend a free software Scrambler Therapy Data Manager (STDM), which can alert the operators in real-time if there is a potential problem in the treatment so that patients can have a better outcome. Salahadin Abdi, MD, PhD* Thomas J. Smith, MD, FACP, FASCO, FAAHPMw Giuseppe Marineo, DScz *Department of Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX wDepartment of Oncology, Johns Hopkins Medical Institutions, Sidney Kimmel Comprehensive Cancer Center Baltimore, MD zDelta Research & Development, Centro Ricerche Bioingegneria Medica, University of Rome “Tor Vergata,” Rome, Italy
REFERENCES 1. Moon JY, Kurihara C, Beckles JP, et al. Predictive factors associated with success and failure for Calmare (Scrambler) therapy: a multi-center analysis. Clin J Pain. 2014. [Epub ahead of print]. 2. Marineo G, Iorno V, Gandini C, et al. Scrambler therapy may relieve chronic neuropathic pain more effectively than guideline-based drug management: results of a pilot, randomized, controlled trial. J Pain Symptom Manage. 2012;43: 87–95. 3. Sabato AF, Marineo G, Gatti A. Scrambler therapy. Minerva Anesthesiol. 2005; 71:479–482. 4. Smith TJ, Coyne PJ, Parker GL, et al. Pilot trial of a patient-specific cutaneous electrostimulation device (MC5-A Calmare) for chemotherapy-induced peripheral neuropathy. J Pain Symptom Manage. 2010;40:883–891. 5. Pachman DR, Weisbrod BL, Seisler DK, et al. Pilot evaluation of scrambler therapy for the treatment of chemotherapy-induced peripheral neuropathy. Support Care Cancer. 2014. [Epub ahead of print].
www.clinicalpain.com |
Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
929
