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Accuracy of botulinum toxin injections in myofascial pain. Response to Gobel et al. Pain 2006;125:82–8
Pain 130 (2007) 299–305 www.elsevier.com/locate/pain
Letters to the Editor Accuracy of botulinum toxin injections in myofascial pain. Response to Gobel et al. Pain 2006;125:82–8 Go¨bel et al. report on the positive effects of botulinum toxin (BTX) injections in upper back myofascial pain syndrome (Gobel et al., 2006). This is the first positive placebo-controlled multicentre study in a large cohort. However, the results are in contrast to several other major trials but confirm the positive effects seen in smaller or older studies. As to our experience (unpublished data) the efficacy of BTX injections depends widely on the accuracy of identification of active myofascial trigger points (MTrPs). The correct identification is the basis for exact injections and the outcome of the treatment. According to the clinical diagnostic criteria of Simons, (i) a local tenderness in (ii) a taut band which produces (iii) a referred pain pattern which has to be (iv) recognized by the patient as a part of his experienced pain are all together the minimal criteria to diagnose safely an active MTrP (Simons et al., 1999). In most of the published studies these criteria did not receive sufficient attention but only partly. The correct injection technique has been described elsewhere (Reilich and Pongratz, 2003; Reilich et al., 2004). In this context it is interesting that the diffusion of the toxin is not able to counterbalance adequately an incorrect injection and the eliciting of a twitch response during injection by the needle seems to improve the efficacy of the treatment, additionally. However, further studies on the observed changes of the micro-milieu within a trigger point before and after treatment (Gerwin et al., 2004) could explain the importance of accurate injection techniques in future. Even if Go¨bel et al. give no more details on the injection technique the above-mentioned points could count for the positive outcome in this trial. In addition, the duration of disease plays a certain role with a likely worse response in the group more than 1.5 years duration, possibly due to fibrotic changes of muscle fibers. Upcoming trials have to investigate all these mentioned aspects in detail. References Gerwin RD, Dommerholt J, Shah JP. An expansion of SimonsÕ integrated hypothesis of trigger point formation. Curr Pain Headache Rep 2004;8:468–75.
Gobel H, Heinze A, Reichel G, Hefter H, Benecke R. Dysport myofascial pain study group. Efficacy and safety of a single botulinum type A toxin complex treatment (Dysport) for the relief of upper back myofascial pain syndrome: results from a randomized double-blind placebo-controlled multicentre study. Pain 2006;125:82–8. Reilich P, Pongratz D. Myofascial pain syndrome. In: Jost WH, editor. Botulinum toxin in painful diseases. Pain Headache, vol. 14. Basel: Karger; 2003. p. 23–41. Reilich P, Fheodoroff K, Kern U, Mense S, Seddigh S, Wissel J, Pongratz D. Consensus statement: botulinum toxin in myofascial pain. J Neurol 2004;251(Suppl. 1):I36–8. Simons DG, Travell JG, Simons LS. Travell SimonsÕ myofascial pain and dysfunction: the trigger point manual. Vol. 1: upper half of body. 2nd ed. Baltimore: Williams&Wilkins, 1999.
Peter Reilich * Benedikt G.H. Schoser Friedrich-Baur-Institute, Ludwig-Maximilians-University, Ziemssenstr. 1, D-80336 Mu¨nchen, Germany E-mail address: [email protected] (P. Reilich).
* Corresponding author. Tel.: +49 89 5160 7400; fax: +49 89 5160 7402. 0304-3959/$32.00 Ó 2007 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.pain.2007.04.020
AuthorsÕ reply to the letter to the editor by Peter Reilich and Benedikt G.H. Schoser regarding the published article entitled ‘‘Efficacy and safety of a single botulinum type A toxin complex treatment (DysportÒ) for the relief of upper back myofascial pain syndrome: Results from a randomised double-blind placebo-controlled multicentre study’’, Pain 2006;125: 82–8. Dear Editor, Peter Reilich and Benedikt G.H. Schoser (2007) point out the critical importance of the injection technique and the selection of injection sites when using botulinum toxin for treatment of myofascial pain. We also consider exact localization of trigger points according to the Simons diagnostic criteria to be an important prerequisite for effective therapy. There are, however, other
Letters to the Editor Accuracy of botulinum toxin injections in myofascial pain. Response to Gobel et al. Pain 2006;125:82–8 Go¨bel et al. report on the positive effects of botulinum toxin (BTX) injections in upper back myofascial pain syndrome (Gobel et al., 2006). This is the first positive placebo-controlled multicentre study in a large cohort. However, the results are in contrast to several other major trials but confirm the positive effects seen in smaller or older studies. As to our experience (unpublished data) the efficacy of BTX injections depends widely on the accuracy of identification of active myofascial trigger points (MTrPs). The correct identification is the basis for exact injections and the outcome of the treatment. According to the clinical diagnostic criteria of Simons, (i) a local tenderness in (ii) a taut band which produces (iii) a referred pain pattern which has to be (iv) recognized by the patient as a part of his experienced pain are all together the minimal criteria to diagnose safely an active MTrP (Simons et al., 1999). In most of the published studies these criteria did not receive sufficient attention but only partly. The correct injection technique has been described elsewhere (Reilich and Pongratz, 2003; Reilich et al., 2004). In this context it is interesting that the diffusion of the toxin is not able to counterbalance adequately an incorrect injection and the eliciting of a twitch response during injection by the needle seems to improve the efficacy of the treatment, additionally. However, further studies on the observed changes of the micro-milieu within a trigger point before and after treatment (Gerwin et al., 2004) could explain the importance of accurate injection techniques in future. Even if Go¨bel et al. give no more details on the injection technique the above-mentioned points could count for the positive outcome in this trial. In addition, the duration of disease plays a certain role with a likely worse response in the group more than 1.5 years duration, possibly due to fibrotic changes of muscle fibers. Upcoming trials have to investigate all these mentioned aspects in detail. References Gerwin RD, Dommerholt J, Shah JP. An expansion of SimonsÕ integrated hypothesis of trigger point formation. Curr Pain Headache Rep 2004;8:468–75.
Gobel H, Heinze A, Reichel G, Hefter H, Benecke R. Dysport myofascial pain study group. Efficacy and safety of a single botulinum type A toxin complex treatment (Dysport) for the relief of upper back myofascial pain syndrome: results from a randomized double-blind placebo-controlled multicentre study. Pain 2006;125:82–8. Reilich P, Pongratz D. Myofascial pain syndrome. In: Jost WH, editor. Botulinum toxin in painful diseases. Pain Headache, vol. 14. Basel: Karger; 2003. p. 23–41. Reilich P, Fheodoroff K, Kern U, Mense S, Seddigh S, Wissel J, Pongratz D. Consensus statement: botulinum toxin in myofascial pain. J Neurol 2004;251(Suppl. 1):I36–8. Simons DG, Travell JG, Simons LS. Travell SimonsÕ myofascial pain and dysfunction: the trigger point manual. Vol. 1: upper half of body. 2nd ed. Baltimore: Williams&Wilkins, 1999.
Peter Reilich * Benedikt G.H. Schoser Friedrich-Baur-Institute, Ludwig-Maximilians-University, Ziemssenstr. 1, D-80336 Mu¨nchen, Germany E-mail address: [email protected] (P. Reilich).
* Corresponding author. Tel.: +49 89 5160 7400; fax: +49 89 5160 7402. 0304-3959/$32.00 Ó 2007 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.pain.2007.04.020
AuthorsÕ reply to the letter to the editor by Peter Reilich and Benedikt G.H. Schoser regarding the published article entitled ‘‘Efficacy and safety of a single botulinum type A toxin complex treatment (DysportÒ) for the relief of upper back myofascial pain syndrome: Results from a randomised double-blind placebo-controlled multicentre study’’, Pain 2006;125: 82–8. Dear Editor, Peter Reilich and Benedikt G.H. Schoser (2007) point out the critical importance of the injection technique and the selection of injection sites when using botulinum toxin for treatment of myofascial pain. We also consider exact localization of trigger points according to the Simons diagnostic criteria to be an important prerequisite for effective therapy. There are, however, other