Review Research Paper On Analgesic - Essay for you

Essay for you

Review Research Paper On Analgesic

Rating: 4.5/5.0 (11 Votes)

Category: Research Paper

Description

Review research paper on analgesic

Analgesics

"An aspirin a day keeps the doctor away." Although this saying can be true, it is not only aspirin that can cure the pains of life, but also several other types of analgesics. There are a wide variety of analgesics. More commonly known as painkillers. The narcotic analgesics act on the central nervous system and change the user's perception; they are more often used for severe pain and can make the user develop an addiction. The nonnarcotic analgesics, known as over the counter or OTC, work at the site of the pain. These do not create tolerance or dependence and do not vary the user's perception. OTC's are more commonly used everyday to treat mild pain.
Many people wish to treat familiar pains themselves, such as toothache or headache pain. To treat these types of symptoms, OTC's are used. There are three main types of OTC drugs. They are as follows:
·Aspirin (salicylic acid acetate) is an anti-inflammatory (decreases swelling and inflammation), anti-pyretic (fever reducing), and anti-platelet (decreases platelets in the body to thin blood). Many heart treatment patients take an aspirin a day to prevent blood clotting. However, if aspirin is taken in large quantities over long periods of time, it may cause gastric ulcers or other internal damage. The molecular formula of aspirin is C9H8O4. Some examples of Aspirin are Bayer, Ecotrin, and Aspergum.

·Ibuprofen (propionic acid) is an anti-inflammatory and anti-pyretic. It is often used to treat arthritis, dental pain, menstrual pain, headache, migraine, and back pain. Ibuprofen works by reducing the levels of prostaglandis (substances that cause pain) in the body. This drug is gentler on the stomach than aspirin. The molecular formula of ibuprofen is C13H18O2. Some examples of ibuprofen are Motrin, Advil, and Nuprin.

·Acetaminophen (Paracetamol) is an alternative to aspirin. It is also an anti-inflammatory, anti-pyretic, and anti-platelet. Acetaminophen is much less likely to cause intestinal side affects than aspirin, however overdose of this drug can cause serious liver poisoning. The molecular formula for acetaminophen is C8H9NO2. Some examples of Acetaminophen are Tylenol, Midol, and Panadol.

Each of these OTC analgesics has different side affects and purposes, but they all share three common elements. These elements are Carbon (atomic number 6, atomic mass 12.011), Hydrogen (atomic number 1, atomic mass 1.0079) and Oxygen (atomic number 8, atomic mass 15.999). By looking at the molecular formulas of each type of OTC analgesic, these three common elements form the base for each chemical compound. Acetaminophen has an additional element of Nitrogen (atomic number 7, atomic mass 14.007). Since Nitrogen is unique to acetaminophen, the pain relieving action is slightly different from aspirin and ibuprofen.
These three categories of analgesics are the main over the counter pain relievers. Their modes of action are similar, however, because of the specific molecular formulas, each one reacts differently in the body. So, "An aspirin a day keeps the doctor away", does not have to be just aspirin… think of ibuprofen and acetaminophen too!


Guidos, Barbara.(1986). "Analgesics," Mosby's Medical and Nursing Dictionary. St. Louis, MO: The C.V. Mosby Company.

(May 2, 2000). "Analgesics," Virtual Anesthesia Textbook,
URL#http://www.gasnet.org/mirror/vat/narcotics.html

Fettner, Ann. (1997). "Analgesics," Compton's Interactive Encyclopedia.
Chicago, IL: The Learning Company.
(1999). "OTC Analgesics,"
Physician's Desk Reference.
New York, NY:

How to Cite this Page

MLA Citation:
"Analgesics." 123HelpMe.com. 07 Aug 2016
<http://www.123HelpMe.com/view.asp?id=52589>.

Important Note: If you'd like to save a copy of the paper on your computer, you can COPY and PASTE it into your word processor. Please, follow these steps to do that in Windows:

1. Select the text of the paper with the mouse and press Ctrl+C .
2. Open your word processor and press Ctrl+V .

123HelpMe.com (the "Web Site") is produced by the "Company". The contents of this Web Site, such as text, graphics, images, audio, video and all other material ("Material"), are protected by copyright under both United States and foreign laws. The Company makes no representations about the accuracy, reliability, completeness, or timeliness of the Material or about the results to be obtained from using the Material. You expressly agree that any use of the Material is entirely at your own risk. Most of the Material on the Web Site is provided and maintained by third parties. This third party Material may not be screened by the Company prior to its inclusion on the Web Site. You expressly agree that the Company is not liable or responsible for any defamatory, offensive, or illegal conduct of other subscribers or third parties.

The Materials are provided on an as-is basis without warranty express or implied. The Company and its suppliers and affiliates disclaim all warranties, including the warranty of non-infringement of proprietary or third party rights, and the warranty of fitness for a particular purpose. The Company and its suppliers make no warranties as to the accuracy, reliability, completeness, or timeliness of the material, services, text, graphics and links.

For a complete statement of the Terms of Service, please see our website. By obtaining these materials you agree to abide by the terms herein, by our Terms of Service as posted on the website and any and all alterations, revisions and amendments thereto.

Other articles

Brain Research Bulletin - Journal

Brain Research Bulletin Brain Research Bulletin

The Brain Research Bulletin (BRB) aims to publish novel work that advances our knowledge of molecular and cellular mechanisms that underlie neural network properties associated with behavior, cognition and other brain functions during neurodevelopment and in the adult. Although clinical research is out of the Journal's scope, the BRB also aims to publish translation research that provides insight into biological mechanisms and processes associated with neurodegeneration mechanisms, neurological diseases and neuropsychiatric disorders. The Journal is especially interested in research using novel methodologies, such as optogenetics, multielectrode array recordings and life imaging in wild-type and genetically-modified animal models, with the goal to advance our understanding of how neurons, glia and networks function in vivo.

Manuscripts should use a combination of experimental approaches to address at least two of the general areas aforementioned; research that is exclusively descriptive.

The Brain Research Bulletin (BRB) aims to publish novel work that advances our knowledge of molecular and cellular mechanisms that underlie neural network properties associated with behavior, cognition and other brain functions during neurodevelopment and in the adult. Although clinical research is out of the Journal's scope, the BRB also aims to publish translation research that provides insight into biological mechanisms and processes associated with neurodegeneration mechanisms, neurological diseases and neuropsychiatric disorders. The Journal is especially interested in research using novel methodologies, such as optogenetics, multielectrode array recordings and life imaging in wild-type and genetically-modified animal models, with the goal to advance our understanding of how neurons, glia and networks function in vivo.

Manuscripts should use a combination of experimental approaches to address at least two of the general areas aforementioned; research that is exclusively descriptive in nature will not be considered for publication. For example, manuscripts describing changes in RNA or protein expression patterns alone are not appropriate for publication but can be considered if they include experiments that investigate the function of those proteins or how changes in their expression levels may be related to behavior, plasticity or neurotransmission. In addition, studies that exclusive report on the association of genetic polymorphism with disease, but fail to include additional experiments demonstrating alterations in the gene's expression or to address potential biological mechanisms relevant to the disease, will not be viewed favorably by the Journal.

Brain Research Bulletin offers simple electronic submission. accelerated peer-review and rapid publication. Section Editors are committed to work closely with authors to provide constructive assistance to enhance visibility and impact of published articles. Brain Research Bulletin encourages authors to use high resolution color in figures to enhance the clarity and impact of their publications. The vast majority of our readership access the journal online and there is no charge for color figures in the online version (html/PDF) of your article.

This journal supports the following content innovations

Pharmacogenomics and Opioid Analgesics: Clinical Implications

Department of Medical Laboratories, Faculty of Health and Caring Professions, Technological Educational Institute of Athens, Athens, Greece

Received 14 October 2014; Revised 22 April 2015; Accepted 26 April 2015

Academic Editor: Shen Liang Chen

Copyright © 2015 Eugenia Yiannakopoulou. This is an open access article distributed under the Creative Commons Attribution License. which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Variation exists in patient response on analgesic treatment in terms of efficacy and safety. This variation may be in part explained by pharmacogenomics. This paper aimed to review data on pharmacogenomics of opioid analgesics focusing on the effect of genetic variation on the efficacy and safety of these agents. Current evidence suggests that pharmacogenomics contribute to variation in efficacy and safety of opioids. However, most data come from case control studies and case reports. In addition, a recognized drawback in the field of pharmacogenomics is the common occurrence of false positive association between polymorphisms and the investigated outcome. Prospective studies are needed to further elucidate the clinical implications of available data as well as to define the guidelines for the clinical application of pharmacogenomic data. Furthermore, basic research should focus on the identification of biologically meaningful polymorphisms enabling a hypothesis with biological plausibility driven research in the field of pharmacogenomics of analgesics. Moreover, the publication of relevant negative results should be favoured.

This paper discusses the possible mechanisms of melatonins analgesic properties

This paper discusses the possible mechanisms of melatonins analgesic properties. - GreenMedInfo Summary

Melatonin is a neurohormone secreted by epiphysis and extrapineal structures. It performs several functions including chronobiotic, antioxidant, oncostatic, immune modulating, normothermal, and anxiolytic functions. Melatonin affects the cardiovascular system and gastrointestinal tract, participates in reproduction and metabolism, and body mass regulation. Moreover, recent studies have demonstrated melatonin efficacy in relation to pain syndromes. The present paper reviews the studies on melatonin use in fibromyalgia, headaches, irritable bowel syndrome, chronic back pain, and rheumatoid arthritis. The paper discusses the possible mechanisms of melatonin analgesic properties. On one hand, circadian rhythms normalization results in sleep improvement, which is inevitably disordered in chronic pain syndromes, and activation of melatonin adaptive capabilities. On the other hand, there is evidence of melatonin-independent analgesic effect involving melatonin receptors and several neurotransmitter systems.

Article Published Date. Mar 15, 2016

Study Type. Review

Print Options

Some features are currently member only features. If you are already a member, please login . Otherwise, click here to become a member.

Disqus Login to Comment

Commenting is limited to Members only. If you are already a member, please login to post a comment. If you do not have a member account and would like to become a member, please click here to begin the process to become a member.

Isolated Analgesic Drug - Research Papers - 1039 Words

Isolated Analgesic Drug

a. Lab experiment title and data:
Isolation of the active ingredient in an Analgesic Drug
February 12th, 2013
b. Abstract ( purpose):
Identify analgesic drugs after isolating the active ingredients from tablets. c. Physical data table
Drug | Melting point | Brand names |
Acetylsalicylic acid | 135-136 °C | Aspirin, ASA, acetyl salicylic acid, generic aspirin, empirin. | Acetaminophen | 169-170.5 °C | Tylenol, Datril, Panadol, nonaspirin pain reliever. | Ibuprofen | 75-77 °C | Advil, Brufen, Motrin, Nuprin. |

d. Procedure:
Extraction of active ingredient:
Two tablets Ibuprofen (0.400g) was crushed into powder between 2 pieces of weighing paper by a pestle. Ibuprofen contained a red coat, was odorless, round and long as a regular tablet. After first crush, forceps were used to remove red fragments. The powder after crushing had white color and also odorless. All white powder was added to a 3mL conical vial. Next, 2mL of Methanol was added to the vial by a calibrated Pasteur pipet. Then the vial was capped and mixed by shaking. During the experiment, the cap was loosened once to release any pressure that may have built up in the vial. A cloudy suspension appeared at bottom of the vial after shaking about 4-5 minutes. Until the precipitate had settled completely, the liquid phase was transferred to a centrifuge tube and this extraction was repeated with a second 2mL of Methanol. The liquid was clearer after second shaking. After that, the mixture was centrifuged about 2 minutes and 30 seconds (setting high speed at 2). After centrifuge, clear liquid appeared above the white-pink solid. Next, the liquid was transferred to a regular test tube. Column Chromatography:

A Pasteur pipet was used to prepare an alumina column. The small ball cotton was pushed down to the bottom of pipet by a wooden-stick. Alumina (0.5g) was added to the pipet (about approximately 2cm high of alumina in the pipet). A small beaker was placed under the column. To the.

Please sign up to read full document.

YOU MAY ALSO FIND THESE DOCUMENTS HELPFUL

Abstract: In this lab, the chemical components of Excedrin and Tylenol, two common, over-the-counter analgesicdrugs . were determined by utilizing the technique of thin-layer chromatography, or TLC. The active ingredients of Excedrin were caffeine, acetaminophen, and aspirin with Rf values of 0.11, 0.38, and 0.61, respectively. The lone active ingredient of Tylenol was acetaminophen with an Rf value of 0.39. The elution sequence obtained in the experiment is as.

1468 Words | 5 Pages

Sasha Thiel 09.10.2012 CH203 Lab Experiment 1: Isolation of the Active Ingredient in an AnalgesicDrug Pre-Lab: A. Least accurate to most accurate 1. Beakers (5ml markings) 2. 10ml graduated cylinder (0.1 markings) 3. 5ml vials (0.1 and 0.3 markings) 4. 1ml plastic pipets (0.1 ml markings) 5. 1ml syringes (0.1 ml markings) 6. 1ml graduated volumetric pipets (0.01 ml markings) B. A 1ml graduated volumetric pipet is the best to.

1344 Words | 5 Pages

Drugs Introduction to Drugs . A drug is a substance which may have medicinal, intoxicating, performance enhancing or other effects when taken or put into a human body or the body of another animal and is not considered a food or exclusively a food. What is considered a drug rather than a food varies between cultures, and distinctions between drugs and foods and between kinds of drug are enshrined.

1752 Words | 8 Pages

of AnalgesicDrugs Purpose: The purpose of this experiment is to identify the brand name of an unknown commercial analgesic product by TLC analysis. Unknown #1 solution was run against standard solutions of individual analgesics . The components of the unknown product were identified by comparing characteristic traits, such as Rf, fluorescence and iodine staining, to those exhibited by the standards. The name of the commercial product.

616 Words | 3 Pages

AnalgesicsAnalgesics . or painkillers, come in many varieties. Most consumers know the various brand names, but may not know that they are in different pharmacological classifications. For instance, Tylenol and Motrin are two drugs that behave differently on the human body to achieve similar results. While most consumers do not think about what they put into their bodies, maybe they should. They would find that the various painkillers could markedly.

753 Words | 3 Pages

January 24, 2013 TLC Analysis of AnalgesicDrugs Introduction: The purpose of this lab was to determine the composition of four different over-the-counter drugs (Anacin, Bufferin, Excedrin, and Tylenol). These compositions were determined by using the method of thin-layer chromatography (TLC) of the four over-the-counter drugs . which were then compared to four different components of drugs (acetaminophen, aspirin.

1291 Words | 7 Pages

ingredient in an AnalgesicDrug from extraction, filtration and melting point. Chm237 Abstract: Acetaminaphen was crushed then extracted for the active ingredient by mixing it with methanol. Then separated from the binders by centrifugation and a filtration technique using a Pasteur pipet packed with alumina. The remaining solvent was then evaporated to yield the solid analgesic (.2295g, 45.9% yield) which was collected by.

783 Words | 4 Pages

of Selected Drugs and Diseases on the Central Nervous System Due May 4th, 2015 Unit 7 Assignment 2 AP 1 – Monday Morning Melissa Rios ABSTRACT The purpose of this paper is to provide information about the drugs Alcohol, Aspirin, Lidocaine, Morphine, Ketamine and succinylcholine. It’s important to understand what they are, what they do, how they are broken down in the body (physically and chemically) and what diseases they can either treat.

999 Words | 6 Pages

A systematic review of randomized trials evaluating regional techniques for postthoracotomy analgesia - National Library of Medicine - PubMed Health

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

A systematic review of randomized trials evaluating regional techniques for postthoracotomy analgesia

GP Joshi, F Bonnet, R Shah, RC Wilkinson, F Camu, B Fischer, EA Neugebauer, N Rawal, SA Schug, C Simanski, and H Kehlet.

Review published: 2008.

CRD summary

This review assessed regional analgesic techniques for the management of post-thoracotomy pain. The authors concluded that thoracic paravertebral block was an effective alternative to thoracic epidural local anaesthetic alone and was associated with reduced complications. In light of uncertainty over parts of the review process and the strength of evidence the findings should be treated with caution.

Authors' objectives

To assess regional analgesic techniques for the management of post-thoracotomy pain.

Searching

MEDLINE and EMBASE were searched for English-language studies to May 2004; search terms were reported.

Study selection

Randomised controlled trials (RCTs ) of regional analgesic or anaesthetic interventions in adult thoracotomy were eligible for inclusion. Included studies compared the following interventions with each other or with systemic analgesia: thoracic epidural local anaesthetic plus opioid; thoracic epidural local anaesthetic or opioid alone; intrathecal opioid; thoracic paravertebral block using local anaesthetic with or without opioid; intercostal nerve block with local anaesthetic; interpleural local anaesthetic and/or opioid. The age of study participants was not reported. The primary outcome was postoperative pain scores. Secondary outcomes were supplementary analgesic requirements and a number of adverse effects, including nausea. vomiting and pulmonary complications.

The authors stated neither how the papers were selected for review nor how many reviewers performed the selection.

Assessment of study quality

Methodological quality was assessed by grading of allocation concealment: A adequate; B unclear; C inadequate; and D not used. Quality was also assessed using the Jadad scale 5-point scale evaluating randomisation. blinding and withdrawals; a score of 5 was classed as high quality.

The authors did not state how the validity assessment was performed.

Data extraction

Means and standard deviations of pain scores were extracted to calculate weighted mean differences; pain scores on a verbal rating scale or numerical rating scale were converted to visual analogue scale. Numbers of patients and events were extracted to calculate odds ratios (OR) for adverse events.

The authors stated neither how the data were extracted nor how many reviewers performed the data extraction.

Methods of synthesis

Studies that reported similar outcomes were pooled by meta-analysis. The pooled weighted mean difference (WMD) and corresponding 95% confidence intervals (CI) were calculated. The reviewers used X 2 and I 2 statistics to calculate heterogeneity (p≤0.10 was considered significant) in the meta-analysis. Where heterogeneity was detected among the included studies, a random-effects model was used. When heterogeneity was absent a fixed-effects model was used. Studies were excluded from the meta-analyses if they did not report mean, standard deviation or standard error of the mean or the proportion of patients. Qualitative and quantitative analyses were stratified according to mode of delivery and type of analgesic in each comparison group, with the effectiveness of each technique assessed through the number of studies that reported a significant difference between groups.

Results of the review

Seventy four studies were included (number of participants not reported), most of which had a quality score of at least 3; nine studies described appropriate allocation concealment.

Thoracic epidural analgesia using local anaesthetic plus opioid, local anaesthetic alone or lipophilic opioid alone was associated with significant reductions in pain scores compared with systemic opioid analgesia (12 of 14 studies). Comparison of thoracic epidural combining local anaesthetic plus opioid with systemic opioid analgesia showed a significant reduction in pain scores for three days (WMD -14.50, 95% CI -21.74 to -7.26; five studies) and an increase in the incidence of hypotension (OR 3.80, 95% CI 1.57 to 9.23; four studies). Paravertebral block was superior to control in reducing pain scores on day one (WMD -8.68, 95% CI -14.79 to -2.57; four studies) and significantly reduced the incidence of pulmonary complications (OR 0.17, 95% CI 0.09 to 0.33; seven studies). A number of additional comparisons were reported with mixed results or non-significant findings.

Authors' conclusions

Thoracic paravertebral block was an effective alternative to thoracic epidural local anaesthetic alone and was associated with reduced incidence of postoperative pulmonary complications compared with systemic analgesia.

CRD commentary

The review question and inclusion criteria were stated clearly. The literature search was restricted to publications in English and it was unclear whether unpublished studies were sought, so language and/or publication bias could have been present and some studies may have been missed. Limited details of the included studies were reported in the review, although online details were available as supplementary material. It was unclear how all stages of the review process were undertaken, therefore, it it was not possible to assess whether appropriate steps were taken to reduce reviewer error and bias. Appropriate criteria were used to assess the quality of the included studies, but most achieved only a Jadad score of 3 and as the results of the assessment were not reported for each study it was unclear on which criteria most studies failed. For some of the quantitative comparisons the number of studies and participants were small and there were wide confidence intervals for the estimates of effect. In light of these uncertainties the authors’ conclusions may be overstated and should be treated with caution.

Implications of the review for practice and research

Practice. The authors stated that the efficacy of thoracic epidural combining local anaesthetic plus opioid, as well as thoracic epidural alone and thoracic epidural lipophilic opioid alone for thoracotomy were supported by the review. Thoracic paravertebral block with local anaesthetic, as a bolus and continuous infusion for two to three days was recommended. Where thoracic epidural or paravertebral techniques were not possible, or contraindicated, then intercostal nerve block or preoperative intrathecal opioid was recommended.

Research. The authors stated that further studies are required to assess whether thoracic paravertebral block is equivalent to thoracic epidural combining local anaesthetic plus opioid with respect to pain relief and morbidity.

Funding

Pfizer Inc. New York, USA.

Bibliographic details

Joshi GP, Bonnet F, Shah R, Wilkinson RC, Camu F, Fischer B, Neugebauer EA, Rawal N, Schug SA, Simanski C, Kehlet H. A systematic review of randomized trials evaluating regional techniques for postthoracotomy analgesia. Anesthesia and Analgesia 2008; 107(3): 1026-1040. [PubMed. 18713924 ]

Original Paper URL Indexing Status

Subject indexing assigned by NLM

MeSH

Analgesia /methods; Analgesia, Epidural /methods; Analgesics, Opioid /therapeutic use; Humans; Hypotension /etiology; Nerve Block; Odds Ratio; Pain, Postoperative /drug therapy ; Randomized Controlled Trials as Topic; Thoracotomy /methods; Treatment Outcome

AccessionNumber Database entry date Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Review research paper on analgesic

Analgesia Photobiomodulation: Implications for Anesthesia and Pain Relief. Transcranial low-level laser therapy (810 nm) temporarily inhibits peripheral nociception: photoneuromodulation of glutamate receptors, prostatic acid phophatase, and adenosine triphosphate.

Pires de Sousa MV1, Ferraresi C2, Kawakubo M3, Kaippert B4, Yoshimura EM5, Hamblin MR6.

Author information
1Massachusetts General Hospital, Wellman Center for Photomedicine, BAR414, 40 Blossom Street, Boston, Massachusetts 02114, United States; University of São Paulo, Institute of Physics, Laboratory of Radiation Dosimetry and Medical Physics, Rua do Matão, Travessa R, 187, Cidade Universitária, São Paulo, Brazil; Bright Photomedicine Ltd. CIETEC Building, 2242 Lineu Prestes, São Paulo 05508-000, Brazil.
2Massachusetts General Hospital, Wellman Center for Photomedicine, BAR414, 40 Blossom Street, Boston, Massachusetts 02114, United States; Federal University of São Carlos, Department of Physical Therapy, Laboratory of Electro-Thermo-Phototherapy, Street Washington Luis, km 235. Monjolinho, São Carlos, São Paulo 13565-905, Brazil; Federal University of São Carlos, Post-Graduation Program in Biotechnology, Street Washington Luis, km 235. Monjolinho, São Carlos, São Paulo 13560-000, Brazil; University of São Paulo, Optics Group, Physics Institute of São Carlos, Street Miguel Petroni, 146-Jardim Bandeirantes, São Carlos, São Paulo 13560-970, Brazil.
3Massachusetts General Hospital. Wellman Center for Photomedicine, BAR414, 40 Blossom Street, Boston, Massachusetts 02114, United States.
4Massachusetts General Hospital, Wellman Center for Photomedicine, BAR414, 40 Blossom Street, Boston, Massachusetts 02114, United States; Federal University of Rio de Janeiro, Carlos Chagas Filho, 373-Cidade Universitária, Rio de Janeiro, RJ 21941-170, Brazil.
5University of São Paulo. Institute of Physics, Laboratory of Radiation Dosimetry and Medical Physics, Rua do Matão, Travessa R, 187, Cidade Universitária, São Paulo, Brazil.
6Massachusetts General Hospital, Wellman Center for Photomedicine, BAR414, 40 Blossom Street, Boston, Massachusetts 02114, United States; Harvard Medical School, Department of Dermatology, 50 Staniford Street #807, Boston, Massachusetts 02114, United States; Harvard-MIT, Division of Health Sciences and Technology, 77 Massachusetts Avenue, E25-518, Cambridge, Massachusetts 02139, United States.

Abstract
Photobiomodulation or low-level light therapy has been shown to attenuate both acute and chronic pain, but the mechanism of action is not well understood. In most cases, the light is applied to the painful area, but in the present study we applied light to the head. We found that transcranial laser therapy (TLT) applied to mouse head with specific parameters (810 nm laser, [Formula: see text], 7.2 or [Formula: see text]) decreased the reaction to pain in the foot evoked either by pressure (von Frey filaments), cold, or inflammation (formalin injection) or in the tail (evoked by heat). The pain threshold increasing is maximum around 2 h after TLT, remains up to 6 h, and is finished 24 h after TLT. The mechanisms were investigated by quantification of adenosine triphosphate (ATP), immunofluorescence, and hematoxylin and eosin (H&E) staining of brain tissues. TLT increased ATP and prostatic acid phosphatase (an endogenous analgesic) and reduced the amount of glutamate receptor (mediating a neurotransmitter responsible for conducting nociceptive information). There was no change in the concentration of tubulin, a constituent of the cytoskeleton, and the H&E staining revealed no tissue damage. This is the first study to show inhibition of peripheral pain due to photobiomodulation of the central nervous system.

Angle Orthod. 2012 Dec 14. [Epub ahead of print]

Effect of frequent laser irradiation on orthodontic pain.

Kim WT, Bayome M, Park JB, Park JH, Baek SH, Kook YA.

a Former graduate student, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Korea.

Abstract Objective: To analyze the effect of low-level laser therapy (LLLT) on perception of pain after separator placement and compare it with perceptions of control and placebo groups using a frequent irradiation protocol.

Materials and Methods: Eighty-eight patients were randomly allocated to a laser group, a light-emitting diode (LED) placebo group, or a control group. Elastomeric separators were placed on the first molars. In the laser and LED groups, first molars were irradiated for 30 seconds every 12 hours for 1 week using a portable device. Pain was marked on a visual analog scale at predetermined intervals. Repeated measure analysis of variance was performed for statistical analysis.

Results: The pain scores of the laser group were significantly lower than those of the control group up to 1 day. The pain scores in the LED group were not significantly different from those of the laser group during the first 6 hours. After that point, the pain scores of the LED group were not significantly different from those of the control.

Conclusions: Frequent LLLT decreased the perception of pain to a nonsignificant level throughout the week after separator placement, compared with pain perception in the placebo and control groups. Therefore, LLLT might be an effective method of reducing orthodontic pain.

Masui. 2012 Jul;61(7):718-27.

Pain treatment with low reactive level laser (LLLT).

[Article in Japanese]

Hosokawa T, Kawabata Y.

Department of Pain Management & Palliative Care Medicine, Kyoto Prefectural University of Medicine, Kyoto.

Noninvasive and low reactive level laser (LLLT) is used as one of the light therapies without giving pain to the patient. Therefore, it is used often clinically in pain treatment, orthopedics, plastic surgery, dermatology, and dentistry. In the pain clinic field, it is one of the procedures indispensable to treatment of various pain including postherpetic neuralgia, diabetic neuropathy or myofascial pain. In recent years the mechanism has been gradually elucidated by basic study. The action is on sensory nerve, sympathetic nerve, blood vessel, immunity, inflammation and central nervous system, and is thought to contribute to analgesia. Also, many reports such as action to inhibit “itch”, a promotor action of the bone metabolism, and the follicular maturation acceleration action have tested and elucidated these mechanisms, and will add further adaptation that will be new in future. Furthermore, development and downsizing of the free electron laser will promote elucidation of the low response level laser therapy. We expect much in the future of the LLLT.

Lasers Med Sci. 2012 Jul 21. [Epub ahead of print]

Analgesic effect of a low-level laser therapy (830 nm) in early orthodontic treatment.

Artés-Ribas M, Arnabat-Dominguez J, Puigdollers A.

Dental School, International University of Catalunya, Campus Sant Cugat, Josep Trueta s/n, 08195-St. Cugat del Vallès, Barcelona, Spain.

The aim of this study was to evaluate the pain sensation that orthodontic patients experience when elastic separators are placed between molars and premolars and to determine the degree of analgesic efficacy of low-level laser therapy (LLLT) compared to a placebo treatment. The study was conducted with 20 volunteers who were fitted with elastic separators between the maxillary molars and premolars. One quadrant was randomly chosen to be irradiated with an 830-nm laser, 100 mW, beam diameter of 7 mm, 250 mW/cm(2) applied for 20 s per point (5 J/cm(2)). Three points were irradiated in the buccal face and three were irradiated in the palate. The same procedure was applied in the contralateral quadrant with a placebo light. A visual analogue scale was used to assess pain 5 min, 6 h, 24 h, 48 h, and 72 h after placement of the separators. Maximum pain occurred 6-24 h after placement of the elastic separators. Pain intensity was significantly lower in the laser-treated quadrant (mean, 7.7 mm) than in the placebo-treated quadrant (mean, 14.14 mm; p?=?0.0001). LLLT at these parameters can reduce pain in patients following placement of orthodontic rubber separators.

Photomed Laser Surg. 2012 Jun 29. [Epub ahead of print]

Meta-Analysis of Pain Relief Effects by Laser Irradiation on Joint Areas.

Department of Information and Communications, Gwangju Institute of Science and Technology. Gwangju, Republic of Korea.

Abstract Background: Laser therapy has been proposed as a physical therapy for musculoskeletal disorders and has attained popularity because no side effects have been reported after treatment. However, its true effectiveness is still controversial because several clinical trials have reported the ineffectiveness of lasers in treating pain.

Methods: In this systematic review, we investigate the clinical effectiveness of low-level laser therapy (LLLT) on joint pain. Clinical trials on joint pain satisfying the following conditions are included: the laser is irradiated on the joint area, the PEDro scale score is at least 5, and the effectiveness of the trial is measured using a visual analogue scale (VAS). To estimate the overall effectiveness of all included clinical trials, a mean weighted difference in change of pain on VAS was used.

Results: MEDLINE is the main source of the literature search. After the literature search, 22 trials related to joint pain were selected. The average methodological quality score of the 22 trials consisting of 1014 patients was 7.96 on the PEDro scale; 11 trials reported positive effects and 11 trials reported negative effects. The mean weighted difference in change of pain on VAS was 13.96?mm (95% CI, 7.24-20.69) in favor of the active LLLT groups. When we only considered the clinical trials in which the energy dose was within the dose range suggested in the review by Bjordal et al. in 2003 and in World Association for Laser Therapy (WALT) dose recommendation, the mean effect sizes were 19.88 and 21.05?mm in favor of the true LLLT groups, respectively.

Conclusions: The review shows that laser therapy on the joint reduces pain in patients. Moreover, when we restrict the energy doses of the laser therapy into the dose window suggested in the previous study, we can expect more reliable pain relief treatments.

Med Chem. 2012 Jan;8(1):33-9.

Modulation of signal-transducing function of neuronal membrane Na+,K+-ATPase by endogenous ouabain and low-power infrared radiation leads to pain relief.

Lopatina EV, Yachnev IL, Penniyaynen VA, Plakhova VB, Podzorova SA, Shelykh TN, Rogachevsky IV, Butkevich IP, Mikhailenko VA, Kipenko AV, Krylov BV.

Pavlov Institute of Physiology of Russian Academy of Sciences, St. Petersburg, Russia.

Effects of infrared (IR) radiation generated by a low-power Co2-laser on sensory neurons of chick embryos were investigated by organotypic culture method. Low-power IR radiation firstly results in marked neurite suppressing action, probably induced by activation of Na+,K+-ATPase signal-transducing function. A further increase in energy of radiation leads to stimulation of neurite growth. We suggest that this effect is triggered by activation of Na+,K+-ATPase pumping function. Involvement of Na+,K+-ATPase in the control of the transduction process was proved by results obtained after application of ouabain at very low concentrations. Physiological significance of low-power IR radiation and effects of ouabain at nanomolar level was investigated in behavioral experiments (formalin test). It is shown that inflammatory pain induced by injection of formalin is relieved both due to ouabain action and after IR irradiation.

Med Chem. 2012 Jan;8(1):14-21.

Mechanism of pain relief by low-power infrared irradiation: ATP is an IR-target molecule in nociceptive neurons.

Yachnev IL, Plakhova VB, Podzorova SA, Shelykh TN, Rogachevsky IV, Krylov BV.

Pavlov Institute of Physiology of Russian Academy of Sciences, St. Petersburg, Russia.

Effects of infrared (IR) radiation generated by a low-power CO2-laser on the membrane of cultured dissociated nociceptive neurons of newborn rat spinal ganglia were investigated using the whole-cell patch-clamp method. Low-power IR radiation diminished the voltage sensitivity of activation gating machinery of slow sodium channels (Na(v)1.8). Ouabain known to block both transducer and pumping functions of Na+,K+-ATPase eliminated IR irradiation effects. The molecular mechanism of interaction of CO2-laser radiation with sensory membrane was proposed. The primary event of this interaction is the process of energy absorption by ATP molecules. The transfer of vibrational energy from Na+,K+- ATPase-bound and vibrationally excited ATP molecules to Na+,K+-ATPase activates this enzyme and converts it into a signal transducer. This effect leads to a decrease in the voltage sensitivity of Na(v)1.8 channels. The effect of IR-radiation was elucidated by the combined application of a very sensitive patch-clamp method and an optical facility with a controlled CO2-laser. As a result, the mechanism of interaction of non-thermal low-power IR radiation with the nociceptive neuron membrane is suggested.

Med Chem. 2012 Jan 1;8(1):33-9.

Modulation of signal-transducing function of neuronal membrane na+,k by endogenous ouabain and low-power infrared radiation leads to pain relief.

Lopatina EV, Yachnev IL, Penniyaynen VA, Plakhova VB, Podzorova SA, Shelykh TN, Rogachevsky IV, Butkevich IP, Mikhailenko VA, Kipenko AV, Krylov BV.

Pavlov Institute of Physiology of Russian Academy of Sciences, Nab. Makarova 6, 199034, St. Petersburg, Russia. krylov@infran.ru

Effects of infrared (IR) radiation generated by a low-power Co2-laser on sensory neurons of chick embryos were investigated by organotypic culture method. Low-power IR radiation firstly results in marked neurite suppressing action, probably induced by activation of Na+,K+-ATPase signal-transducing function. A further increase in energy of radiation leads to stimulation of neurite growth. We suggest that this effect is triggered by activation of Na+,K+-ATPase pumping function. Involvement of Na+,K+-ATPase in the control of the transduction process was proved by results obtained after application of ouabain at very low concentrations. Physiological significance of low-power IR radiation and effects of ouabain at nanomolar level was investigated in behavioral experiments (formalin test). It is shown that inflammatory pain induced by injection of formalin is relieved both due to ouabain action and after IR irradiation.

Photomed Lasers Surg. 2011 Jun;29(6):365-81. Epub 2011 Apr 1.

Inhibitory effects of laser irradiation on peripheral mammalian nerves and relevance to analgesic effects: a systematic review.

Chow R, Armati P, Laakso EL, Bjordal JM, Baxter GD.

Nerve Research Foundation, Brain and Mind Research Institute, The University of Sydney, Camperdown, New South Wales, Australia. robertachow@iinet.net.au

The objective of this review was to systematically identify experimental studies of non-ablative laser irradiation (LI) on peripheral nerve morphology, physiology, and function. The findings were then evaluated with special reference to the neurophysiology of pain and implications for the analgesic effects of low-level laser therapy (LLLT).

LLLT is used in the treatment of pain, and laser-induced neural inhibition has been proposed as a mechanism. To date, no study has systematically evaluated the effects of LI on peripheral nerve, other than those related to nerve repair, despite the fact that experimental studies of LI on nerves have been conducted over the past 25 years.

We searched computerized databases and reference lists for studies of LI effects on animal and human nerves using a priori inclusion and exclusion criteria.

We identified 44 studies suitable for inclusion. In 13 of 18 human studies, pulsed or continuous wave visible and continuous wave infrared (IR) LI slowed conduction velocity (CV) and/or reduced the amplitude of compound action potentials (CAPs). In 26 animal experiments, IR LI suppressed electrically and noxiously evoked action potentials including pro-inflammatory mediators. Disruption of microtubule arrays and fast axonal flow may underpin neural inhibition.

This review has identified a range of laser-induced inhibitory effects in diverse peripheral nerve models, which may reduce acute pain by direct inhibition of peripheral nociceptors. In chronic pain, spinal cord changes induced by LI may result in long-term depression of pain. Incomplete reporting of parameters limited aggregation of data.

Photomed Laser Surg. 2011 Sep 9. [Epub ahead of print]

Treatment of Persistent Idiopathic Facial Pain (PIFP) with a Low-Level Energy Diode Laser.

Yang HW, Huang YF.

1 Oral Medicine Center, Chung Shan Medical University Hospital. Taichung City, Taiwan .

Abstract Objective: The purpose of this study was to test the therapeutic efficacy of low- level energy diode laser on persistent idiopathic facial pain (PIFP). Background data: PIFP has presented a diagnosis and management challenge to clinicians. Many patients were misdiagnosed, which resulted in unnecessary dental procedures. Low-level energy diode laser therapy has been applied to different chronic and acute pain disorders, including neck, back, and myofacial pain; degenerative osteoarthritis; and headache, and it may be an effective alternative treatment for PIFP.

Methods: A total of 16 patients, who were diagnosed with PIFP, were treated with an 800-nm wavelength diode laser. A straight handpiece having an end size of 0.8?cm in diameter, or an angled handpiece with an end size of 0.5?cm in diameter was used. When laser was applied, the handpiece directly contacted the involved symptomatic region with an energy density of 105?J/cm(2). Overall pain and discomfort was analyzed with a 10-cm visual analogue scale (VAS) before and after treatment. Results: All patients received diode laser therapy between 1 and10 times. The average pain score was 7.4 before the treatment (ranging from 2.9 to 9.8), and 4.1 after the treatment. An average pain reduction of 43.87% (ranging from 9.3% to 91.8%) was achieved. The pain remained unchanged at a lower level for up to 12 months.

Conclusions: Low-level energy diode laser may be an effective treatment for PIFP.

Arq Neuropsiquiatr. 2011;69(2B):356-9.

Low-level laser therapy, at 830 nm, for pain reduction in experimental model of rats with sciatica.

Bertolini GR, Artifon EL, Silva TS, Cunha DM, Vigo PR.

Source

Injury and Physiotherapeutic Resource Study Laboratory, Western Paraná State University, Cascavel, PR, Brazil.

Abstract

Chronic pain, resulting from nerve compression, is a common clinical presentation. One means of conservative treatment is low-level laser therapy, although controversial. The aim of this study was to evaluate the effects of two doses of low-level laser, at 830 nm, on pain reduction in animals subjected to sciatica. Eighteen rats were used, divided into three groups: GS (n=6), sciatica and simulated treatment; G4J (n=6), sciatica and treatment with 4 J/cm²; and G8J (n=6), sciatica and irradiation with 8 J/cm². The right sciatic nerve was exposed and compressed using catgut thread. Five days of treatment were started on the third postoperative day. Pain was assessed by means of the paw elevation time during gait: before sciatica, before and after the first and second therapies, and the end of the fifth therapy. Low-level laser was effective in reducing the painful condition.

Lasers Med Sci. 2011 May 31. [Epub ahead of print]

The effect of two phototherapy protocols on pain control in orthodontic procedure-a preliminary clinical study.

Esper MA, Nicolau RA, Arisawa EA.

Source

Centro de Laserterapia e Fotobiologia, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911 – Bairro Urbanova, 12244-000, São José dos Campos, SP, Brazil, angela_esper@hotmail.com

Abstract

Phototherapy with low-level coherent light (laser) has been reported as an analgesic and anti-inflammatory as well as having a positive effect in tissue repair in orthodontics. However, there are few clinical studies using low-level LED therapy (non-coherent light). The aim of the present study was to analyze the pain symptoms after orthodontic tooth movement associated with and not associated with coherent and non-coherent phototherapy. Fifty-five volunteers (mean age?=?24.1?±?8.1 years) were randomly divided into four groups: G1 (control), G2 (placebo), G3 (protocol 1: laser, InGaAlP, 660 nm, 4 J/cm(2), 0.03 W, 25 s), G4 (protocol 2: LED, GaAlAs, 640 nm with 40 nm full-bandwidth at half-maximum, 4 J/cm(2), 0.10 W, 70 s). Separators were used to induce orthodontic pain and the volunteers pain levels were scored with the visual analog scale (VAS) after the separator placement, after the therapy (placebo, laser, or LED), and after 2, 24, 48, 72, 96, and 120 h. The laser group did not have statistically significant results in the reduction of pain level compared to the LED group. The LED group had a significant reduction in pain levels between 2 and 120 h compared to the control and the laser groups. The LED therapy showed a significant reduction in pain sensitivity (an average of 56%), after the orthodontic tooth movement when compared to the control group.

Photomed Laser Surg. 2011 Apr 1. [Epub ahead of print]

Inhibitory Effects of Laser Irradiation on Peripheral Mammalian Nerves and Relevance to Analgesic Effects: A Systematic Review.

Chow R, Armati P, Laakso EL, Bjordal JM, Baxter GD.

1 Nerve Research Foundation, Brain and Mind Research Institute, The University of Sydney. Camperdown, New South Wales, Australia .

Abstract

Abstract Objective: The objective of this review was to systematically identify experimental studies of non-ablative laser irradiation (LI) on peripheral nerve morphology, physiology, and function. The findings were then evaluated with special reference to the neurophysiology of pain and implications for the analgesic effects of low-level laser therapy (LLLT).

Background: LLLT is used in the treatment of pain, and laser-induced neural inhibition has been proposed as a mechanism. To date, no study has systematically evaluated the effects of LI on peripheral nerve, other than those related to nerve repair, despite the fact that experimental studies of LI on nerves have been conducted over the past 25 years.

Methods: We searched computerized databases and reference lists for studies of LI effects on animal and human nerves using a priori inclusion and exclusion criteria.

Results: We identified 44 studies suitable for inclusion. In 13 of 18 human studies, pulsed or continuous wave visible and continuous wave infrared (IR) LI slowed conduction velocity (CV) and/or reduced the amplitude of compound action potentials (CAPs). In 26 animal experiments, IR LI suppressed electrically and noxiously evoked action potentials including pro-inflammatory mediators. Disruption of microtubule arrays and fast axonal flow may underpin neural inhibition.

Conclusions: This review has identified a range of laser-induced inhibitory effects in diverse peripheral nerve models, which may reduce acute pain by direct inhibition of peripheral nociceptors. In chronic pain, spinal cord changes induced by LI may result in long-term depression of pain. Incomplete reporting of parameters limited aggregation of data.

Eur Arch Paediatr Dent. 2011 Apr;12(2):93-5.

The effect of low level laser therapy on pain during dental tooth-cavity preparation in children.

Tanboga I, Eren F, Altinok B, Peker S, Ertugral F.

Dr I. Tanboga, Marmara Üniversitesi Di? Hekimli?i Fak. Pedodonti AD, Büyükçiftlik sok. No:6 Kat:4, Ni?anta. i?li/?stanbul 34365, Turkey. Email: itanboga@marmara.edu.tr

Abstract

AIM: To evaluate the effect of low level laser therapy on pain during cavity preparation with laser in paediatric dental patients.

STUDY DESIGN AND METHODS: The study was carried out on 10 children aged 6 to 9 years old for a total of 20 primary molar teeth. For laser preparation an Er: YAG laser was used. Half of the preparations were treated by low level laser therapy (LLLT) before laser preparation and the remaining half without LLLT (non-LLLT) before laser preparation. All cavities were prepared by ER:YAG laser, restored with light-cured composite resin following the application of acid etching and bonding agent. Children were instructed to rate their pain on the visual analogue scale (VAS) from 0 to 5 points. Statistical analyses were performed using Mann Whitney U test.

RESULTS: VAS Median (min-max) scores were 1(0-2) for LLLT and 3(1-4) for the non-LLT treated children. Between LLLT and non- LLLT groups results were statistically significant (p<0.01).

CONCLUSIONS: The use of LLLT before cavity preparation with laser decreased pain in paediatric dental patients.

Clin J Pain. 2010 Oct;26(8):729-36.

A meta-analysis of the efficacy of laser phototherapy on pain relief.

Fulop AM, Dhimmer S, Deluca JR, Johanson DD, Lenz RV, Patel KB, Douris PC, Enwemeka CS.

College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.

Abstract

OBJECTIVE: Laser phototherapy has been widely used to relieve pain for more than 30 years, but its efficacy remains controversial. To ascertain the overall effect of phototherapy on pain, we aggregated the literature and subjected the studies to statistical meta-analysis.

METHODS: Relevant original studies were gathered from every available source and coded. Articles that met preestablished inclusion criteria were subjected to statistical meta-analysis, using Cohen’s d statistic to determine treatment effect sizes.

RESULTS: Fifty-two effect sizes were computed from the 22 articles that met the inclusion criteria. The resulting overall mean effect size was highly significant; d = +0.84 (95% confidence interval = 0.44-1.23). The effect size remained significant even when a high outlying d value was conservatively excluded from the analysis; d = +0.66 (95% confidence interval = 0.46-0.86). The fail-safe number associated with the overall treatment effect, that is, the number of additional studies in which phototherapy has negative or no effect on pain needed to negate the overall large effect size of +0.84, was 348.

DISCUSSION: These findings warrant the conclusion that laser phototherapy effectively relieves pain of various etiologies; making it a valuable addition to contemporary pain management armamentarium.

Photomed Laser Surg. 2010 Jun;28(3):417-22.

Effects of low-level laser therapy on pain and scar formation after inguinal herniation surgery: a randomized controlled single-blind study.

Carvalho RL, Alcântara PS, Kamamoto F, Cressoni MD, Casarotto RA.

Postgraduate Program in Rehabilitation Sciences, University of São Paulo, São Paulo, Brazil.

The aim of this study was to investigate the efficacy of an infrared GaAlAs laser operating with a wavelength of 830 nm in the postsurgical scarring process after inguinal-hernia surgery.

Low-level laser therapy (LLLT) has been shown to be beneficial in the tissue-repair process, as previously demonstrated in tissue culture and animal experiments. However, there is lack of studies on the effects of LLLT on postsurgical scarring of incisions in humans using an infrared 830-nm GaAlAs laser.

Twenty-eight patients who underwent surgery for inguinal hernias were randomly divided into an experimental group (G1) and a control group (G2). G1 received LLLT, with the first application performed 24 h after surgery and then on days 3, 5, and 7. The incisions were irradiated with an 830-nm diode laser operating with a continuous power output of 40 mW, a spot-size aperture of 0.08 cm(2) for 26 s, energy per point of 1.04 J, and an energy density of 13 J/cm(2). Ten points per scar were irradiated. Six months after surgery, both groups were reevaluated using the Vancouver Scar Scale (VSS), the Visual Analog Scale, and measurement of the scar thickness.

G1 showed significantly better results in the VSS totals (2.14 +/- 1.51) compared with G2 (4.85 +/- 1.87); in the thickness measurements (0.11 cm) compared with G2 (0.19 cm); and in the malleability (0.14) compared with G2 (1.07). The pain score was also around 50% higher in G2.

Infra-red LLLT (830 nm) applied after inguinal-hernia surgery was effective in preventing the formation of keloids. In addition, LLLT resulted in better scar appearance and quality 6 mo postsurgery.

The Lancet, Early Online Publication, 13 November 2009

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.

Dr Roberta T Chow MBBS a. Prof Mark I Johnson PhD b, Prof Rodrigo AB Lopes-Martins PhD c, Prof Jan M Bjordal PT d e

Neck pain is a common and costly condition for which pharmacological management has limited evidence of efficacy and side-effects. Low-level laser therapy (LLLT) is a relatively uncommon, non-invasive treatment for neck pain, in which non-thermal laser irradiation is applied to sites of pain. We did a systematic review and meta-analysis of randomised controlled trials to assess the efficacy of LLLT in neck pain.

We searched computerised databases comparing efficacy of LLLT using any wavelength with placebo or with active control in acute or chronic neck pain. Effect size for the primary outcome, pain intensity, was defined as a pooled estimate of mean difference in change in mm on 100 mm visual analogue scale.

We identified 16 randomised controlled trials including a total of 820 patients. In acute neck pain, results of two trials showed a relative risk (RR) of 1·69 (95% CI 1·22—2·33) for pain improvement of LLLT versus placebo. Five trials of chronic neck pain reporting categorical data showed an RR for pain improvement of 4·05 (2·74—5·98) of LLLT. Patients in 11 trials reporting changes in visual analogue scale had pain intensity reduced by 19·86 mm (10·04—29·68). Seven trials provided follow-up data for 1—22 weeks after completion of treatment, with short-term pain relief persisting in the medium term with a reduction of 22·07 mm (17·42—26·72). Side-effects from LLLT were mild and not different from those of placebo.

We show that LLLT reduces pain immediately after treatment in acute neck pain and up to 22 weeks after completion of treatment in patients with chronic neck pain.

Masui. 2009 Nov;58(11):1401-6.

Phototherapy for chronic pain treatment

[Article in Japanese]

Department of Anesthesia, Toho University Sakura Medical Center Sakura 285-8741.

Three types of machines are used in the field of phototherapy for chronic pain. One type is an instrument for low reactive level laser therapy (LLLT), one is an instrument for linear polarized infrared light irradiation (SUPER LIZER), and the last one is an instrument for Xenon light irradiation (beta EXCEL Xe10). The available machines for LLLT all project laser by semiconductor. The newest machine (MEDILASER SOFT PULSE10) has peak power of 10 W and mean power of 1 W. This machine is as safe as 1 W machine and is effective twice as deep as the 1 W machine. The irradiation by low reactive level laser induces hyperpolarization, decreased resistance of neuronal membrane, and increased intra-cellular ATP concentrations. The effects of low reactive level laser might be induced by the activation of ATP-dependent K channel. The significant analgesic effects of 1 W and 10 W LLLT were reported with double blind test. The significant analgesic effects of linear polarized near infrared light irradiation with double blind test were also reported. The effects of low reactive level laser upon the sympathetic nerve system were thought to result from its normalization of the overloaded sympathetic nerve system.

Cranio. 2009 Oct;27(4):243-7.

Evaluation of low intensity laser therapy in myofascial pain syndrome.

Carrasco TG, Guerisoli LD, Guerisoli DM, Mazzetto MO.

Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.

Limited studies have demonstrated that low intensity laser therapy (LILT) may have a therapeutic effect on the treatment of myofascial pain syndrome (MPS). Sixty (60) patients with MPS and having one active trigger point in the anterior masseter and anterior temporal muscles were selected and assigned randomly to six groups (n=10): Groups I to Ill were treated with GaAIAS (780 nm) laser, applied in continuous mode and in a meticulous way, twice a week, for four weeks. Energy was set to 25 J/cm2, 60 J/cm2 and 105 J/cm2, respectively. Groups IV to VI were treated with placebo applications, simulating the same parameters as the treated groups. Pain scores were assessed just before, then immediately after the fourth application, immediately after the eighth application, at 15 days and one month following treatment. A significant pain reduction was observed over time (p<0.001). The analgesic effect of the LILT was similar to the placebo groups. Using the parameters described in this experiment, LILT was effective in reducing pain experienced by patients with myofascial pain syndrome. Thus, it was not possible to establish a treatment protocol. Analyzing the analgesic effect of LILT suggests it as a possible treatment of MPS and may help to establish a clinical protocol for this therapeutic modality.

Photomed Laser Surg. [Epub ahead of print]

Acute Low Back Pain with Radiculopathy: A Double-Blind, Randomized, Placebo-Controlled Study.

Konstantinovic LM, Kanjuh ZM, Milovanovic AN, Cutovic MR, Djurovic AG, Savic VG, Dragin AS, Milovanovic ND.

1 Clinic for Rehabilitation, Medical School. Belgrade, Serbia.

Abstract Objective: The aim of this study was to investigate the clinical effects of low-level laser therapy (LLLT) in patients with acute low back pain (LBP) with radiculopathy. Background Data: Acute LBP with radiculopathy is associated with pain and disability and the important pathogenic role of inflammation. LLLT has shown significant anti-inflammatory effects in many studies. Materials and Methods: A randomized, double-blind, placebo-controlled trial was performed on 546 patients. Group A (182 patients) was treated with nimesulide 200 mg/day and additionally with active LLLT; group B (182 patients) was treated only with nimesulide; and group C (182 patients) was treated with nimesulide and placebo LLLT. LLLT was applied behind the involved spine segment using a stationary skin-contact method. Patients were treated 5 times weekly, for a total of 15 treatments, with the following parameters: wavelength 904 nm; frequency 5000 Hz; 100-mW average diode power; power density of 20 mW/cm(2) and dose of 3 J/cm(2); treatment time 150 sec at whole doses of 12 J/cm(2). The outcomes were pain intensity measured with a visual analog scale (VAS); lumbar movement, with a modified Schober test; pain disability, with Oswestry disability score; and quality of life, with a 12-item short-form health survey questionnaire (SF-12). Subjects were evaluated before and after treatment. Statistical analyses were done with SPSS 11.5. Results: Statistically significant differences were found in all outcomes measured (p < 0.001), but were larger in group A than in B (p < 0.0005) and C (p < 0.0005). The results in group C were better than in group B (p < 0.0005). Conclusions: The results of this study show better improvement in acute LBP treated with LLLT used as additional therapy.

Masui. 2009 Nov;58(11):1401-6.

Phototherapy for chronic pain treatment

[Article in Japanese]

Department of Anesthesia, Toho University Sakura Medical Center Sakura 285-8741.

Three types of machines are used in the field of phototherapy for chronic pain. One type is an instrument for low reactive level laser therapy (LLLT), one is an instrument for linear polarized infrared light irradiation (SUPER LIZER), and the last one is an instrument for Xenon light irradiation (beta EXCEL Xe10). The available machines for LLLT all project laser by semiconductor. The newest machine (MEDILASER SOFT PULSE10) has peak power of 10 W and mean power of 1 W. This machine is as safe as 1 W machine and is effective twice as deep as the 1 W machine. The irradiation by low reactive level laser induces hyperpolarization, decreased resistance of neuronal membrane, and increased intra-cellular ATP concentrations. The effects of low reactive level laser might be induced by the activation of ATP-dependent K channel. The significant analgesic effects of 1 W and 10 W LLLT were reported with double blind test. The significant analgesic effects of linear polarized near infrared light irradiation with double blind test were also reported. The effects of low reactive level laser upon the sympathetic nerve system were thought to result from its normalization of the overloaded sympathetic nerve system.

Med Oral Patol Oral Cir Bucal. 2008 Oct 1;13(10):E648-52

Analgesic action of laser therapy (LLLT) in an animal model.

Pozza DH, Fregapani PW, Weber JB, de Oliveira MG, de Oliveira MA, Ribeiro Neto N, de Macedo Sobrinho JB.

Laser Technology, Universidade Federal da Paraíba and Universidade Federal da Bahia, Universidade do Porto, Portugal.

OBJECTIVES: To evaluate the analgesic effect of laser therapy on healthy tissue of mice. STUDY DESIGN: Forty-five animals were divided in three groups of 15: A–infrared laser irradiation (830 nm, Kondortech, São Carlos, SP, Brazil); B–red laser irradiation (660 nm, Kondortech, São Carlos, SP, Brazil); C– ham irradiation with laser unit off. After laser application, the mice remained immobilized for the injection of 30 microl of 2% formalin in the plantar pad of the irradiated hind paw. The time that the mouse kept the hind paw lifted was measured at 5 min intervals for 30 minutes. RESULTS: Results showed statistically significant differences comparing the control group with the infrared laser group at 5, 20, 25 and 30 accumulated minutes, and with the red laser group at all time points. The analysis of partial times, at each 5 minutes, showed statistically significant differences between the control and the laser groups up to 20 minutes. CONCLUSIONS: Laser therapy had an analgesic effect and red laser had the best results.

Anesth Analg. 2008 Sep;107(3):1058-63.

Pre-Irradiation of blood by gallium aluminum arsenide (830 nm) enhances peripheral endogenous opioid analgesia in rats.

Hagiwara S, Iwasaka H, Hasegawa A, Noguchi T.

Department of Brain and Nerve Science, Anesthesiology, Oita University Faculty of Medicine, 1-1 Idaigaoka-Hasamamachi-Yufu City-Oita 879-5593, Japan. saku@med.oita-u.ac.jp

BACKGROUND: Low-level laser therapy (LLLT) has been reported to relieve pain, free of side effects. However, the mechanisms underlying LLLT are not well understood. Recent studies have also demonstrated that opioid-containing immune cells migrate to inflamed sites and release beta-endorphins to inhibit pain as a mode of peripheral endogenous opioid analgesia. We investigated whether pre-irradiation of blood by LLLT enhances peripheral endogenous opioid analgesia.

METHODS: The effect of LLLT pretreatment of blood on peripheral endogenous opioid analgesia was evaluated in a rat model of inflammation. Additionally, the effect of LLLT on opioid production was also investigated in vitro in rat blood cells. The expression of the beta-endorphin precursors, proopiomelanocortin and corticotrophin releasing factor, were investigated by reverse transcription polymerase chain reaction.

RESULTS: LLLT pretreatment produced an analgesic effect in inflamed peripheral tissue, which was transiently antagonized by naloxone. Correspondingly, beta-endorphin precursor mRNA expression increased with LLLT, both in vivo and in vitro.

CONCLUSION: These findings suggest that that LLLT pretreatment of blood induces analgesia in rats by enhancing peripheral endogenous opioid production, in addition to previously reported mechanisms.

J Peripher Nerv Syst. 2007 Mar;12(1):28-39.

830 nm laser irradiation induces varicosity formation, reduces mitochondrial membrane potential and blocks fast axonal flow in small and medium diameter rat dorsal root ganglion neurons: implications for the analgesic effects of 830 nm laser.

Chow RT, David MA, Armati PJ

The authors report the formation of 830 nm (cw) laser-induced, reversible axonal varicosities, using immunostaining with beta-tubulin, in small and medium diameter, TRPV-1 positive, cultured rat DRG neurons. Laser also induced a progressive and statistically significant decrease in MMP in mitochondria in and between static axonal varicosities. In cell bodies of the neuron, the decrease in MMP was also statistically significant, but the decrease occurred more slowly. Importantly we also report for the first time that 830 nm (cw) laser blocked fast axonal flow, imaged in real time using confocal laser microscopy and JC-1 as mitotracker. Control neurons in parallel cultures remained unaffected with no varicosity formation and no change in MMP. Mitochondrial movement was continuous and measured along the axons at a rate of 0.8 mum/s (range 0.5-2 mum/s), consistent with fast axonal flow. Photoacceptors in the mitochondrial membrane absorb laser and mediate the transduction of laser energy into electrochemical changes, initiating a secondary cascade of intracellular events. In neurons, this results in a decrease in MMP with a concurrent decrease in available ATP required for nerve function, including maintenance of microtubules and molecular motors, dyneins and kinesins, responsible for fast axonal flow. Laser-induced neural blockade is a consequence of such changes and provide a mechanism for a neural basis of laser-induced pain relief. The repeated application of laser in a clinical setting modulates nociception and reduces pain. The application of laser therapy for chronic pain may provide a non-drug alternative for the management of chronic pain.

Photomed Laser Surg. 2005 Feb;23(1):60-5

Retrospective study of adjunctive diode laser therapy for pain attenuation in 662 patients: detailed analysis by questionnaire.

Nakaji S, Shiroto C, Yodono M, Umeda T, Liu Q.

Department of Hygiene, Hirosaki University School of Medicine, Aomori, Japan.

OBJECTIVE: The aim of this study was to assess the long-term effects of low-level laser therapy (LLLT) through a retrospective survey using questionnaires.

BACKGROUND DATA: The use of LLLT for chronic pain attenuation has been reported in the international literature for over 20 years.

METHODS: We used a series of diode laser systems in which the most effective wavelength was consistently found to be 830 nm with an output power in continuous-wave of 60 mW. Subjects were 1,087 patients treated by LLLT at the Shiroto Clinic from April 1992 to August 1995. Questionnaires were sent to subjects in September and October 1996.

RESULTS: The reply rate was 60.9%, comprising 662 questionnaires (265 males, 397 females, mean age of 53.4 years). The total efficacy rating (excellent plus good) immediately after LLLT was 46.8% in men and 47% in women. At the time of the survey, this rose to 73.3% in men and 76.8% in women, with positive effects also recorded on psychosomatic factors such as well-being, physical energy, general fatigue, mental vigor, and emotional stability. LLLT effects continued for 1-3 days. No statistically significant difference in efficacy was seen between males and females. LLLT as used in the study is therefore considered safe, effective, and side-effect-free, making it an ideal adjunctive therapeutic modality for intractable chronic and other pain.

CONCLUSION: Infrared diode LLLT is therefore considered safe, effective, and side-effect-free, making it an ideal adjunctive therapeutic modality for intractable chronic pain.

Wiad Lek. 2006;59(9-10):630-3.

Comparison of analgetic effect of magnetic and laser stimulation before oral surgery procedures.

[Article in Polish]

Koszowski R, Smieszek-Wilczewska J, Dawiec G.

Z Katedry i Zak?adu Chirurgii Stomatologicznej w Bytomiu Slaskiej Akademii Medycznej w Katowicach. chirstom@slam.katowice.pl

Oral surgery procedures are often the cause of painful sensations because of their tissue invasiveness. To avoid these sensations a wide use of nonsteroid antiinflammatory drugs is usually accepted. Because of plenty side effects of these drugs alternative antipain agents are desired. The goal of this study was to assess antipain effect of laser stimulation and alternating magnetic field in oral surgery procedures. Pain sensations in patients during: local anesthetics application, surgical procedure and after it were assessed according to VAS scale. Level of stomatological fear was assessed with the use of Corah’s scale. Achieved results were analyzed statistically. Conclusion of this analysis is that laser stimulation and alternating magnetic field applied directly before oral surgery procedure are effective antipain agents that decrease intra and postoperative sensations. It was observed that patients with high level of stomatological fear had more pain sensations but even in this group laser and magnetic stimulation significantly lowered these complaints.

Photomed Laser Surg. 2004 Aug;22(4):323-9.

The efficacy of low-power lasers in tissue repair and pain control: a meta-analysis study.

Enwemeka CS, Parker JC, Dowdy DS, Harkness EE, Sanford LE, Woodruff LD.

School of Health Professions, Behavioral and Life Sciences, New York Institute of Technology, Old Westbury, NY 11568-8000, USA. Enwemeka@nyit.edu

Abstract

OBJECTIVE: We used statistical meta-analysis to determine the overall treatment effects of laser phototherapy on tissue repair and pain relief.

BACKGROUND DATA: Low-power laser devices were first used as a form of therapy more than 30 years ago. However, their efficacy in reducing pain or promoting tissue repair remains questionable.

METHODS: Following a literature search, studies meeting our inclusion criteria were identified and coded. Then, the effect size of laser treatment, that is, Cohen’s d, was calculated from each study using standard meta-analysis procedures.

RESULTS: Thirty-four peer-reviewed papers on tissue repair met our inclusion criteria and were used to calculate 46 treatment effect sizes. Nine peer-reviewed papers on pain control met the inclusion criteria and were used to calculate nine effect sizes. Meta-analysis revealed a positive effect of laser phototherapy on tissue repair (d = +1.81; n = 46) and pain control (d = +1.11; n = 9). The positive effect of treatment on specific indices of tissue repair was evident in the treatment effect sizes determined as follows: collagen formation (d = +2.78), rate of healing (d = +1.57), tensile strength (d = +2.13), time needed for wound closure (d = +0.76), tensile stress (d = +2.65), number and rate of degranulation of mast cells (d = +1.87), and flap survival (d = +1.95). Further, analysis revealed the positive effects of various wavelengths of laser light on tissue repair, with 632.8 nm having the highest treatment effect (d = +2.44) and 780 nm the least (d = 0.60). The overall treatment effect for pain control was positive as well (d = +1.11). The fail-safe number-that is, the number of studies in which laser phototherapy has negative or no effect-needed to nullify the overall outcome of this analysis was 370 for tissue repair and 41 for pain control.

CONCLUSIONS: These findings mandate the conclusion that laser phototherapy is a highly effective therapeutic armamentarium for tissue repair and pain relief.

Photomed Laser Surg. 2005 Apr;23(2):177-81.

Analgesic effect of He-Ne (632.8 nm) low-level laser therapy on acute inflammatory pain.

Ferreira DM, Zângaro RA, Villaverde AB, Cury Y, Frigo L, Piccolo G, Longo I, Barbosa DG.

Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, São Paulo, SP, Brazil.

OBJECTIVE: The aim of this study was to evaluate the analgesic effect of the low level laser therapy (LLLT) with a He-Ne laser on acute inflammatory pain, verifying the contribution of the peripheral opioid receptors and the action of LLLT on the hyperalgesia produced by the release of hyperalgesic mediators of inflammation.

BACKGROUND DATA: All analgesic drugs have undesired effects. Because of that, other therapies are being investigated for treatment of the inflammatory pain. Among those, LLLT seems to be very promising.

MATERIAL AND METHODS: Male Wistar rats were used. Three complementary experiments were done. (1) The inflammatory reaction was induced by the injection of carrageenin into one of the hind paws. Pain threshold and volume increase of the edema were measured by a pressure gauge and plethysmography, respectively. (2) The involvement of peripheral opioid receptors on the analgesic effect of the laser was evaluated by simultaneous injection of carrageenin and naloxone into one hind paw. (3) Hyperalgesia was induced by injecting PGE2 for the study of the effect of the laser on the sensitization increase of nociceptors. A He-Ne laser (632.8 nm) of 2.5 J/cm2 was used for irradiation.

RESULTS: We found that He-Ne stimulation increased the pain threshold by a factor between 68% and 95% depending on the injected drug. We also observed a 54% reduction on the volume increase of the edema when it was irradiated.

CONCLUSION: He-Ne LLLT inhibits the sensitization increase of nociceptors on the inflammatory process. The analgesic effect seems to involve hyperalgesic mediators instead of peripheral opioid receptors.

Photomed Laser Surg. 2004 Aug;22(4):306-11.

Comparison of laser, dry needling, and placebo laser treatments in myofascial pain syndrome.

Ilbuldu E, Cakmak A, Disci R, Aydin R.

Department of Physical Medicine and Rehabilitation, Istanbul Medical Faculty, Istanbul University, 34390 Sehremini, Istanbul, Turkey.

Abstract

OBJECTIVE: We aimed to evaluate the effectiveness of laser therapy in myofascial pain syndrome treatment.

BACKGROUND DATA: Myofascial pain syndrome is a disease that is characterized by hypersensitive points called trigger points found in one or more muscles and/or connective tissues. It can cause pain, muscle spasm, sensitivity, stiffness, weakness, limitation of range of motion and rarely autonomic dysfunction. Physical therapy modalities and exercise are used in the treatment of this frequently encountered disease.

METHODS: The placebo controlled, prospective, long-term follow up study was planned with 60 patients who had trigger points in their upper trapezius muscles. The patients were divided into three groups randomly. Stretching exercises were taught to each group and they were asked to exercise at home. Treatment duration was 4 weeks. Placebo laser was applied to group 1, dry needling to group 2 and laser to group 3. He-Ne laser was applied to three trigger points in the upper trapezius muscles on both sides with 632.8 nm. The patients were assessed at before, post-treatment, and 6 months after-treatment for pain, cervical range of motion and functional status.

RESULTS: We observed a significant decrease in pain at rest, at activity, and increase in pain threshold in the laser group compared to other groups. Improvement according to Nottingham Health Profile gave the superiority of the laser treatment. However, those differences among the groups were not observed at 6-month follow up.

CONCLUSIONS: Laser therapy could be useful as a treatment modality in myofascial pain syndrome because of its noninvasiveness, ease, and short-term application.

J Clin Laser Med Surg. 1996 Aug;14(4):163-7.

Low level laser therapy with trigger points technique: a clinical study on 243 patients.

Laser Center, Locarno, Switzerland.

Among the various methods of application techniques in low level laser therapy (LLLT) (HeNe 632.8 nm visible red or infrared 820-830 nm continuous wave and 904 nm pulsed emission) there are very promising “trigger points” (TPs), i.e. myofascial zones of particular sensibility and of highest projection of focal pain points, due to ischemic conditions. The effect of LLLT and the results obtained after clinical treatment of more than 200 patients (headaches and facial pain, skeletomuscular ailments, myogenic neck pain, shoulder and arm pain, epicondylitis humery, tenosynovitis, low back and radicular pain, Achilles tendinitis) to whom the “trigger points” were applied were better than we had ever expected. According to clinical parameters, it has been observed that the rigidity decreases, the mobility is restored (functional recovery), and the spontaneous or induced pain decreases or even disappears, by movement, too. LLLT improves local microcirculation and it can also improve oxygen supply to hypoxic cells in the TP areas and at the same time it can remove the collected waste products. The normalization of the microcirculation, obtained due to laser applications, interrupts the “circulus vitiosus” of the origin of the pain and its development (Melzak: muscular tension > pain > increased tension > increased pain, etc.). Results measured according to VAS/VRS/PTM: in acute pain, diminished more than 70%; in chronic pain more than 60%. Clinical effectiveness (success or failure) depends on the correctly applied energy dose–over/underdosage produces opposite, negative effects on cellular metabolism. We did not observe any negative effects on the human body and the use of analgesic drugs could be reduced or completely excluded. LLLT suggests that the laser beam can be used as monotherapy or as a supplementary treatment to other therapeutic procedures for pain treatment.

Used by the kind permission of the Czech Society for the Use of Lasers in Medicine, www.laserpartner.org .

Lasers and Pain Treatment Dr. Kevin Moore

Department of Anaesthesia

The Royal Oldham Hospital, UK

Summary

The clinical application of low incident power density laser radiation for the treatment of acute and chronic pain is now a well established procedure. This paper reviews the currently available English speaking literature and summarises a selection of serious scientific papers which report a beneficial effect following the treatment of a wide variety of acute and chronic syndromes whose main presenting symptom is pain.

Introduction

The Helium-Neon (He-Ne) laser at a wavelength of 632.8 nm has proved very successful in promoting wound healing particularly in indolent ulcers resistant to conventional methods of therapy. However, its limited depth of penetration and low power output have rendered it less effective when treating more deep seated causes of pain. The laser more frequently used for pain therapy is the Gallium Aluminium Arsenide (GaAlAs) diode emitting coherent light in the near infra-red waveband, usually 820 – 830 nm, and with a continuous wave power output of some 60 mW. The optoelectronic rationale for choosing these parameters has been discussed by Moore and Calderhead (1).

During the past 15 years experimental research has greatly added to our knowledge of the response of tissue radiation. Figure 1 summarises some 10 years work by Karu (2) into the cellular response to photon energy. Additional research at the Tissue Repair Research Unit at Guy`s Hospital, London, has detailed the local tissue changes following exposure to laser light. The current concept is one of a dual response to laser bioactivation.

The immediate or primary effect is a local tissue response to direct irradiation and comprises vasodilatation with increased circulatory flow: enhanced lymphatic drainage; increased neutrophil, macrophage and fibroblast activity; and an improved metabolic function in depressed or damaged cells. The delayed or secondary response consists of a systemic effect caused by circulating photoproducts of irradiation in the blood and lymphatic systems. Increased plasma concentrations of certain types of prostaglandins, enkephalins and endorphins have all been identified and most probably play a major role in the mechanism of pain attenuation.

Figure 1: Cellular response to laser irradiation

PHOTORECEPTORS ON MITOCHONDRIAL CHAINS

ELECTRON TRANSPORT CHAINS PROTON MOTIVE FORCES

RESPIRATION CHAIN ACTIVITY OXIDATION OF NADH POOL

REDOX CHANGES IN MITOCHONDRIA AND CYTOPLASM

CELL MEMBRANE ACTIVITY
MEMBRANE TRANSPORT MECHANISMS

CYTOPLASM CHANGES
?H+ ?ph ?Ca++ ?cAMP

DNA. RNA SYNTHESIS

GROWTH AND PROLIFERATION

Acute pain therapy

Acute trauma is invariably associated with a degree of soft tissue injury comprising swelling, haematoma, pain, reduced mobility and in the lower limbs impaired weight bearing. Sporting injuries and domestic accidents usually involve damage to muscles, joint ligaments and tendons. Examples include a sprained ankle or wristed or a twisted knee. Most extensive soft tissue damage tends to result from industrial crush injuries or road traffic accidents. In the absence of bone fracture or other injury demanding priority treatment laser therapy should be instituted at the earliest opportunity. Kumar (3) reported a comparative study in 50 patients with inversion injuries of the ankle. He found that compared to conventional physiotherapy the laser treated patients showed a more rapid resolution of symptoms and an earlier return to full weight bearing. Patients were treated with a GaAlAs diode laser (830 nm: 60 mW) at 48 hour intervals on a maximum of 3 occasions. A similar therapeutic regime has been described for whiplash injuries of the cervical spine (4). Ben Hatit and Lammens (5) used a defocussed CO2 laser to treat a variety of acute musculoskeletal problems. The energy density varied between 40 – 70 J/cm 2. Patients were treated twice a week for up to 10 sessions.

Beneficial effects of laser therapy in acute small joint inflammation in rheumatoid arthritis has been described by Asada et al (6). Multiple point irradiation using a GaAlAs diode (830 nm:60 mW) was applied for 15 seconds to each point. Pain was reduced by up to 66 % together with an improvement in the measured range of movement (ROM).

In a similar report involving 938 patients with osteoarticular pain Soriano (7) found pain attenuation of 88 % when treating a variety of acute conditions such as tendosynovitis, lumbago and cervical pain. He used a GaAs diode (940 nm: pulsed 10,000 Hz: average power 40 mW) to treat patients twice weekly for a maximum of 10 sessions. The energy density delivered was 6 – 10 J/cm 2 per irradiated point.

Laser therapy also proved helpful in reducing the severity and duration of postoperative pain. In a comparative study involving 20 patients undergoing elective cholecystectomy Moore et al (8) reported a 50 % reduction in the postoperative pain experienced by the laser treated patients together with a concomitant reduction in analgesie requirements.

Chronic pain syndromes

Chronic pain, as the name implies, may last for months or years. Pain may arise as a result of damage caused by trauma or surgery or be manifested as a symptom of a systemic desease process. In later life pain due to musculoskeletal “wear and tear” is very common. Finally neuralgic pain such as postherpetic or trigeminal neuralgia can cause prolonged problems to sufferers. A high percentage of patients referred for laser therapy will have already shown little or no response to conventional methods of treatment.

In rheumatoid arthritis (RA) laser therapy can benefit not only the pain of acute small joint inflammation but also the more established chronic pain of the disease. Gartner (9) in an excellent review article on rheumatology considered some 18 papers published over a 10 year period. All involved double blind trials of therapy with 5 having a cross-over element. In considering the effect of laser therapy in chronic rheumatoid and associated musculoskeletal conditions all but one of the reports noted a significant improvement in pain. In his own work Gartner used a 904 nm infra-red laser to treat a variety of tendinopathies with a better than 80 % success rate in relieving pain. He compared this to a similar rate of pain attenuation using anti-inflammatory drugs

(NSAIDs) but noted that whilst laser therapy was free of side effects some 20 % of patients treated with NSAIDs suffered unacceptable side effects of medication. Asada and his colleagues (10) in a further study of some 170 patients with rheumatoid arthritis used similar laser parameters and treatment protocols to their earlier reported work. The group achieved pain attenuation of up to 90 % and improvement in ROM of up to 56 %.

In a report of some 1000 treatments using a GaAlAs diode laser (830 nm: 60 mW) for a wide variety of chronic pain syndromes Moore (11) noted an overall reduction in pain levels of some 70 %. Trelles et al (12) used a similar diode laser to treat 40 patients with degenerative joint disease to the knee. They delivered 18 J/cm 2 to each of 4 points around the knee twice a week for 8 weeks and reported a significant pain reduction in 82 % with improved joint mobility. Li (13) used a 25 mW combined CO 2 /HeNe laser to treat 90 patients with cervical spondylosis. Laser therapy was administered to a variety of acupuncture points for 10 minutes daily for 2 periods each of 10 days with an intervening rest period of 10 days. 90 % of patients showed symptoms improvement with an excellent result in 43 %.

Fender and Diffee (14) reported an interesting trial involving patients suffering from chronic generalized musculoskeletal pain. They irradiated the stellete ganglion using a HeNe laser with an initial exposure of 6 minutes (36 J/cm 2 ) gradually increasing over 4 – 6 weeks to a maximum of 15 minutes (90 J/cm2). They postulated a mechanism of reduced sympathetic irritability causing a stabilisation of the response loop and a breaking of the pain cycle. In resistant cases they also treated segmental dermatomes and site specific trigger points.

Patients suffering from postherpetic neuralgia (PHN) have shown a good response to laser therapy. In a double blind cross-over trial Moore et al (15) reported a mean reduction in pain levels of 74 %. Patients were treated with a GaAlAs diode (830 nm: 60 mW) with the laser applied in contact mode to the centre of each 2 cm 2 grid over the affected area giving 24 – 30 J/cm 2 to each point. Treatment was given twice a week for 4 weeks. Using an identical treatment protocol but an extended regime of some 12 weeks Kemmotsu et al (16) reported at the end of treatment pain attenuation of 89 %. Otsuka and colleagues (17) used an 8.5 mW HeNe scanner to treat the acute rash of herpes zoster. Once the skin rash has subsided treatment was continued using a GaAlAs laser (830 nm: 60 mW). Within 1 month pain had been reduced by 76 % with a final end treatment improvement of 97 %. The early introduction of laser therapy produced a rapid resolution of acute herpes zoster rash and a reduced incidence of PHN.

Discussion

Laser therapy is effective for a wide variety of acute and chronic pain syndromes. During the past 7 years the Laser Therapy Journal has featured some 30 papers on the subject. The preferred laser is the GaAlAs diode emitting light in the near infra-red usually at 830 nm. The majority of reports detail a power output of 60 mW continuous wave. Recently, however, researchers have been assessing the use of higher output powers in the range of 150 – 300 mW.

In a prelim inary trial Yamada and Ogawa (18) compared the results of treating PHN with 60 and 150 mW. They found that the higher output power reduced both the frequency and duration of the treatment sessions and improved pain attenuation by some 25 %. Ohshiro (19) has devised an ingenious protocol for a computer controlled double blind comparative trial which compensates for the placebo effect of treatment and for patient and therapist bias. In a paper comparing the therapeutic outcomes in 2 geographically separate but otherwise identical clinics Shiroto (20) described how a positive therapist attitude motivated by enthusiasm and commitment can improve the results of therapy by 15 – 20 %.

There remains a need for more scientific studies based on well constructed double blind comparative trials. Nevertheless the bulk of published work to date supports the use of laser therapy for the treatment of pain. In a repor of the cost-effective benefits of using laser therapy to treat PHN Moore (21) noted that, compared with conventional methods of treatment, laser proved to be not only more effective but more economical as well. The added advantage of absence of side effects, non-invasive nature of therapy and the case of application ensured good patient acceptance of the treatment modality.

References
  1. MOORE & CALDERHEAD: The clinical application of low incident power density 830 nm GaAlAs diode laser radiation in the therapy of chronic intractable pain: a historical ond optoelectronic rationale and clinical review. Int. Jour. Optoelectronics 6: 503-520, 1991
  2. KARU: Photobiology of low power laser therapy. Chur, Switzerland, Harwood Academic Publishers, 1989
  3. KUMAr et al. A comparative study of low level laser therapy and conventional physiotherapy for the treatment of inversion injuries of the ankle. Lasers and Medical Science, Abstract issue 298, 1988
  4. OHSHIRO: Low reactive level laser therapy: practical application 103-110, Chichester, UK, John Wiley & Sons, 1991
  5. BEN HATIT & LAMMENS: Laser therapy with defocussed CO2 laser, Laser Therapy 4: 175-178, 1992
  6. ASADA et al. Diode laser therapy for rheumatoid arthritis: a clinical evaluation of 102 joints treated with low reactive level laser therapy (LLLT), Laser Therapy 1: 147-151, 1989
  7. SORIANO: The analgesic effect of 904 nm GaAs semiconductor low level laser therapy (LLLT) on osteoarticular pain: a report on 938 irradiated patients, Laser Therapy 7: 75-80, 1995
  8. MOORE et al. The effect of infra-red diode laser irradiation on the duration and severity of postoperative pain: a double blind trial, Laser Therapy 4: 145-149, 1992
  9. GARTNER: Low reactive level laser therapy (LLLT) in rheumatology: A review of the cllinical experience in the author`s laboratory, Laser Therapy 4: 107-115, 1992
  10. ASADA et al. Clinical application of GaAlAs 830 nm diode laser in treatment of rheumatoid arthritis, Laser Therapy 3: 77-82, 1991
  11. MOORE: LLLT for the treatment of chronic pain, Frontiers of Electro-optics (Conference proceedings) 283-290, 1990
  12. TRELLES et al. Infra-red diode laser in low reactive level laser therapy (LLLT) for knee osteoarthrosis, Laser Therapy 3: 149-153, 1991
  13. LI: Laser therapy for radicular cervical spondylosis, Laser Therapy 4: 151-153, 1992
  14. FENDER & DIFFE: Physiological response in chronic pain patients to a new LLLT protocol, Laser Therapy 4: 169-173, 1992
  15. MOORE et al. A double blind cross-over trial of low level laser therapy in the treatment of postherpetic neuralgia, Laser Therapy (pilot issue) 7-9, 1998
  16. KEMMOTSU et al. Efficacy of low reactive level laser therapy for pain attenuation of postherpetic neuralgia, Laser Therapy 3: 71-75, 1991
  17. OTSUKA et al. Effects of Helium-Neon laser therapy on herpes zoster pain, Laser Therapy 7: 27-32, 1995
  18. YAMADA & OGAWA: Comparative study of 60 mW diode laser therapy and 150 mW diode laser in the treatment of postherpetic neuralgia, Laser Therapy 7: 71-74, 1995
  19. OHSHIRO et al. Critical considerations in protocol design for the double blind trial on pain attenuation by laser therapy, Laser Therapy 6: 101-106, 1994
  20. SHIROTO et al. The importance of therapist education and motivation on diode LLLT efficacy in pain therapy: a comparative study, Laser Therapy 5: 175-179, 1993
  21. MOORE: Cost effective benefits of the use of laser therapy in the treatment of intractable postherpetic neuralgia, Laser Applications in Medicine and Surgery, 61-63 Bologna, Italy, Monduzzi Editore, 1992
Joint International Laser Conference in Edinburgh

In September, 2003, the Edinburgh International Conference Centre in Scotland hosted the Joint International Laser Conference, organized jointly by the American Society for Laser Medicine and Surgery, European Laser Association and British Medical Laser Association. More than 500 registered participants had the opportunity of seeing not only the most advanced laser medical technology presented by 39 exhibitors, but also of attending numerous meetings and presentations, getting acquainted with top issues of laser surgery and therapy. A significant portion of scientific papers and posters dealt with laser therapy (LLLT), and theory was well supplemented with a series of educational courses called “How I do it”. The organizers provided Laser Partner with full text of some of the lectures and now we bring the first one.

Low Level Laser-Therapy in pain treatment of the ambulatory system.

Dr. med. Matteo Rossetto M.D. Basel

Summary

In spring 1995 we expanded our treatment methods with Low Level Laser Therapy. We decided to test the effectiveness of this kind of therapy through a study on 41 consecutive patients with ailments of the ambulatory system. For each case respective parameters, such as diagnosis, localisation, number of treatment points and output of the applied laser energy, were listed on a individual protocol where the patient also had to assess his pain (before and after the treatment) to a number on the so called visual-analog pain scala (rating from 1 to 10). Furthermore the doctor had to note objective parameters like mobility, inflamation and swellings before and after the laser therapy. The indications concerned exclusively pain of the ambulatory system, especially epicondylitis and other posttraumatic or stress induced pain of tendons and articulations, but also some degenerative changes of joints (arthrosis of knee and shoulder).

During this study no other therapy method or drugs were applied, in order to allow a reliable judgement of the effectiveness of laser therapy. Conventional methods were only used if the treatment by laser light was not sufficiently effective.

Generally, the results obtained with laser therapy were very good – both subjectively and objectively rated. Only 12 percents of the patients felt no pain release, one patient had to stop the laser therapy after two applications because of an increasing subjective pain. 73 percent of the patients felt a good or very good effect of the therapy. The treated patients liked laser therapy very much, because there are no side effects, the treatment is painless and the ailment decreases rapidly.

Pain. 1993 Jan;52(1):63-6.

The effect of low-level laser therapy on musculoskeletal pain: a meta-analysis.

Gam AN, Thorsen H, Lonnberg F.

Department of Rheumatology, Bispebjerg Hospital, Copenhagen, Denmark.

A meta-analysis was undertaken of low-level laser therapy (LLLT) on musculoskeletal pain. A literature search revealed 23 LLLT trials and of these 17 were controlled trials. Ten were double blind and 7 were insufficiently blinded. Within the studies identified pain was assessed by visual analogue scale or by “some other indices of pain”. Nine double-blind trials and 4 controlled trials presented results in a form which allowed pooling of data. In the double-blind trials, the mean difference in pain between LLLT and placebo was 0.3% (S.E.(d) 4.6%, confidence limits -10.3-10.9%). In the insufficiently blinded trials the mean difference in pain was 9.5% (S.E.(d) 4.5%, confidence limits -2.9-21.8%). We conclude that LLLT has no effect on pain in musculoskeletal syndromes.

Scand J Rheumatol. 1992;21(3):139-41.

Low level laser therapy for myofascial pain in the neck and shoulder girdle. A double-blind, cross-over study.

Thorsen H, Gam AN, Svensson BH, Jess M, Jensen MK, Piculell I, Schack LK, Skjott K.

Department of General Practice, University of Copenhagen, Denmark.

In a controlled, cross-over study the effect of low level laser therapy (LLLT) was evaluated. During a five weeks period forty-seven female laboratory technicians received six laser and six placebo treatments to tender points in the neck and shoulder girdle. Subjects rated the placebo treatment significantly more beneficial than LLLT (p = .04). There was no reduction in consumption of analgesics associated with either laser or placebo treatment. The results indicate no beneficial effect of LLLT for myofascial pain.

Post navigation

Amyotrophic Lateral Sclerosis

Analgetic Effect – Comparing Laser and Magnetic Stimulation before Oral Surgery