Presented at the 2013 AAPM Annual Meeting « Back

A Pilot Study to Determine the Efficacy of Therapeutic Class IV Laser Treatment on Local Muscle Spasm Associated with Myofascial Pain Syndrome in Patients with Neck Pain

Eric Lee, MD MA, eric.lee2@nyumc.org¹, Michel Dubois, MD², Steven Calvino, MD¹, Rudy Malayil, MD³, Eric Kim, MD⁴, Allyson A. Shrikhande, MD⁵, (1) NYU Langone Medical Center, New York, New York, (2) New York University Pain Medicine Program, New York, New York, (3) NYU Medical Center, New York, New York, (4) NYU School of Medicine, New York, New York, (5) Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York

Introduction: The pathophysiology of myofascial trigger points is incompletely understood(1). Low levels of visible or near infrared light for reducing pain and inflammation (3,4), has been known for many years. Despite positive findings in vitro animal models and randomized controlled clinical trials, low level laser therapy (LLLT) remains controversial(5). The mechanism of LLLT at the cellular level suggests mitochondria and cytochrome c-oxidase contribute to cellular response and reduce prostaglandin synthesis (2,6). Methods: A class IV laser (LT-1000) was used on 10 patients with at least one month of myofascial neck pain. Patients underwent an initial evaluation, two-week laser treatment, and follow up at 15 and 30 days post treatment. A Visual Analogue Scale (VAS), patient reported global impression of change, and muscle pain detection device (MPDD)(7), were used for measurements. Institutional IRB approval was obtained. Results: Baseline mean scores of VAS were 52.9 SD of 32.4, post treatment(Day 15), mean scores reduced to 30.0 SD of 19.9. 77.8% of participants improved after treatment; 22% very much improved, 33% moderate improvement, 22% no change. Objective detection of painful muscles with MPDD showed 71% of patients with positive points pretreatment had no positive trigger points post treatment. Conclusion: Class IV laser therapy showed a majority of patients who underwent treatment reported improvement, as assessed by VAS, Global impression, and MPDD trigger points detection. This encouraging pilot study justifies further studies with larger populations and addition of control groups for laser therapy as a potential non-pharmacological and non-interventional adjunct treatment, for patients with chronic myofascial pain. References: 1) IASP Global Year Against Musculoskeletal Pain October 2009-October 2010 2) T.I. Karu, L.V., et al. Absorption Measurements of Cell Monolayers Relevant to Mechanisms of Laser Phototherapy:Reduction or Oxidation of Cytochrome c Oxidase Under Laser Radiation at 632.8nm. Photomedicine and Laser Surgery, 26(6):593–599, 2008 3) Guzman, J., Neck pain and low-level laser: does it work and how? Lancet 2009 Dec 5;374(9705):1875-6. Epub 2009 Nov 4) Roberta T. Chow et al, Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials The Lancet, Volume 374, Issue 9705, Pages 1897 - 1908, 5 Decemb 5) BIPHASIC DOSE RESPONSE IN LOW LEVEL LIGHT THERAPY Dose-Response (Prepress) Formerly Nonlinearity in Biology, Toxicology, and Medicine Copyright © 2009 University of Massachusetts ISSN: 1559-3258 DOI: 10.2203/dose-response.09-027.Hamblin 6) Yousefi-Nooraie R, et al, Low level laser therapy for nonspecific low-back pain. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD005107. DOI: 10.1002/14651858.CD005107.pub4 7) Hunter, C. et al A new muscle pain detection device to diagnose muscles as a source of back and/or neck pain 2010 Jan;11(1):35-43, Pain medicine.

Funding: None