fMRI of pain studies using laser-induced heat on skin with and without the loved one near the subject - a pilot study on 'love hurts'

NASA Astrophysics Data System (ADS)

Sofina, T.; Kamil, W. A.; Ahmad, A. H.

2014-11-01

The aims of this study are to image and investigate the areas of brain response to laser-induced heat pain, to analyse for any difference in the brain response when a subject is alone and when her loved one is present next to the MRI gantry. Pain stimuli was delivered using Th-YAG laser to four female subjects. Blood-Oxygenation-Level-Dependent (BOLD) fMRI experiment was performed using blocked design paradigm with five blocks of painful (P) stimuli and five blocks of non-painful (NP) stimuli arranged in pseudorandom order with an 18 seconds rest (R) between each stimulation phase. Brain images were obtained from 3T Philips Achieva MRI scanner using 32-channel SENSE head coil. A T1-weighted image (TR/TE/slice/FOV = 9ms/4ms/4mm slices/240×240mm) was obtained for verification of brain anatomical structures. An echo-planar-imaging sequence were used for the functional scans (TR/TE/slice/flip/FOV=2000ms/35ms/4mm slices/90°/220×220mm). fMRI data sets were analysed using SPM 8.0 involving preprocessing steps followed by t-contrast analysis for individuals and FFX analysis. In both with and without-loved-one conditions, neuronal responses were seen in the somatosensory gyrus, supramarginal gyrus, thalamus and insula regions, consistent with pain-related areas. FFX analysis showed that the presence of loved one produced more activation in the frontal and supramarginal gyrus during painful and non-painful stimulations compared to absence of a loved one. Brain response to pain is modulated by the presence of a loved one, causing more activation in the cognitive/emotional area i.e. 'love hurts'.

Modulation of laser-evoked potentials and pain perception by transcutaneous electrical nerve stimulation (TENS): a placebo-controlled study in healthy volunteers.

PubMed

Vassal, François; Créac'h, C; Convers, Ph; Laurent, B; Garcia-Larrea, L; Peyron, R

2013-09-01

To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on brain nociceptive responses (laser-evoked potentials, LEPs) and pain perception. Twenty healthy subjects were included. Nociceptive CO(2)-laser pulses were sequentially delivered to the dorsum of both feet. The amplitude of LEPs and nociceptive thresholds were collected in three consecutive conditions: T1: "sham" TENS (2 Hz/low-intensity) positioned heterotopically, over the left thigh; T2: "active" TENS (120 Hz/low-intensity) applied homotopically, over the left common peroneal nerve; and T3: "sham" TENS (replication of condition T1). Compared with "sham" TENS, "active" TENS significantly decreased the LEPs amplitude. This effect was observed exclusively when "active" TENS was applied ipsilaterally to the painful stimulus. Nociceptive thresholds increased with sessions in both limbs, but the increase observed during the "active" condition of TENS (T2) exceeded significantly that observed during the condition T3 only on the foot ipsilateral to TENS. Compared with a credible placebo TENS, high-frequency TENS induced a significant attenuation of both the acute pain and LEPs induced by noxious stimuli applied on the same dermatome. This modulation of subjective and objective concomitants of pain processing reflects a real neurophysiological TENS-related effect on nociceptive transmission. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry

PubMed Central

Najeeb, Shariq; Khurshid, Zohaib; Zafar, Muhammad Sohail; Ajlal, Syed

2016-01-01

Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future. PMID:26642047

Central Pain Processing in Early-Stage Parkinson's Disease: A Laser Pain fMRI Study

PubMed Central

Petschow, Christine; Scheef, Lukas; Paus, Sebastian; Zimmermann, Nadine; Schild, Hans H.; Klockgether, Thomas; Boecker, Henning

2016-01-01

Background & Objective Pain is a common non-motor symptom in Parkinson’s disease. As dopaminergic dysfunction is suggested to affect intrinsic nociceptive processing, this study was designed to characterize laser-induced pain processing in early-stage Parkinson’s disease patients in the dopaminergic OFF state, using a multimodal experimental approach at behavioral, autonomic, imaging levels. Methods 13 right-handed early-stage Parkinson’s disease patients without cognitive or sensory impairment were investigated OFF medication, along with 13 age-matched healthy control subjects. Measurements included warmth perception thresholds, heat pain thresholds, and central pain processing with event-related functional magnetic resonance imaging (erfMRI) during laser-induced pain stimulation at lower (E = 440 mJ) and higher (E = 640 mJ) target energies. Additionally, electrodermal activity was characterized during delivery of 60 randomized pain stimuli ranging from 440 mJ to 640 mJ, along with evaluation of subjective pain ratings on a visual analogue scale. Results No significant differences in warmth perception thresholds, heat pain thresholds, electrodermal activity and subjective pain ratings were found between Parkinson’s disease patients and controls, and erfMRI revealed a generally comparable activation pattern induced by laser-pain stimuli in brain areas belonging to the central pain matrix. However, relatively reduced deactivation was found in Parkinson’s disease patients in posterior regions of the default mode network, notably the precuneus and the posterior cingulate cortex. Conclusion Our data during pain processing extend previous findings suggesting default mode network dysfunction in Parkinson’s disease. On the other hand, they argue against a genuine pain-specific processing abnormality in early-stage Parkinson’s disease. Future studies are now required using similar multimodal experimental designs to examine pain processing in more advanced stages of Parkinson’s disease. PMID:27776130

Skin denervation does not alter cortical potentials to surface concentric electrode stimulation: A comparison with laser evoked potentials and contact heat evoked potentials.

PubMed

La Cesa, S; Di Stefano, G; Leone, C; Pepe, A; Galosi, E; Alu, F; Fasolino, A; Cruccu, G; Valeriani, M; Truini, A

2018-01-01

In the neurophysiological assessment of patients with neuropathic pain, laser evoked potentials (LEPs), contact heat evoked potentials (CHEPs) and the evoked potentials by the intraepidermal electrical stimulation via concentric needle electrode are widely agreed as nociceptive specific responses; conversely, the nociceptive specificity of evoked potentials by surface concentric electrode (SE-PREPs) is still debated. In this neurophysiological study we aimed at verifying the nociceptive specificity of SE-PREPs. We recorded LEPs, CHEPs and SE-PREPs in eleven healthy participants, before and after epidermal denervation produced by prolonged capsaicin application. We also used skin biopsy to verify the capsaicin-induced nociceptive nerve fibre loss in the epidermis. We found that whereas LEPs and CHEPs were suppressed after capsaicin-induced epidermal denervation, the surface concentric electrode stimulation of the same denervated skin area yielded unchanged SE-PREPs. The suppression of LEPs and CHEPs after nociceptive nerve fibre loss in the epidermis indicates that these techniques are selectively mediated by nociceptive system. Conversely, the lack of SE-PREP changes suggests that SE-PREPs do not provide selective information on nociceptive system function. Capsaicin-induced epidermal denervation abolishes laser evoked potentials (LEPs) and contact heat evoked potentials (CHEPs), but leaves unaffected pain-related evoked potentials by surface concentric electrode (SE-PREPs). These findings suggest that unlike LEPs and CHEPs, SE-PREPs are not selectively mediated by nociceptive system. © 2017 European Pain Federation - EFIC®.

Placebo analgesia is not due to compliance or habituation: EEG and behavioural evidence.

PubMed

Watson, Alison; El-Deredy, Wael; Vogt, Brent A; Jones, Anthony K P

2007-05-28

This study was designed to resolve whether experimental placebo responses are due to either increased compliance or habituation. We stimulated both forearms and recorded laser-evoked potentials from 18 healthy volunteers treated on one arm with a sham analgesic cream and an inactive cream on the other (treatment group), and 13 volunteers with an inactive cream on both arms (controls). The treatment group showed a significant reduction in the pain ratings and laser-evoked potentials with both the sham and inactive creams. The control group showed no evidence of habituation to the laser stimulus. The results indicate that the reduction in pain during experimental placebo response is unlikely to be due to sensory habituation or compliance with the experimental instructions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wise, Nicholas A. D.C.

Cranial Laser Reflex Technique (CLRT) is a novel method involving a brief low level laser stimulation of specific cranial reflex points to reduce musculoskeletal pain. Objective: The objective of the study was to compare the immediate effects of CLRT with a sham treatment on chronic musculoskeletal pain using pressure algometry in a double-blinded randomized controlled trial. Methods: Fifty-seven (57) volunteers with various musculoskeletal pains gave informed consent and were randomly allocated to either the CLRT treatment or sham group. Painful trigger points and/or tender spinal joints were found in each patient. Using a digital algometer, the pain/pressure threshold (PPT) wasmore » determined and a pain rating was given using a numerical pain scale from 0-10. CLRT or a sham treatment was performed with a 50 mW, 840 nm laser, for a maximum of 20 seconds to the each cranial reflex. The initial pressure (PPT) was immediately delivered to the same spot, and the pain rated again. Results: There was a statistically significant difference in pain scores between CLRT and sham groups immediately following treatment. Improvement was reported in 95% of the treatment group, with 59% reporting an improvement of 2 points or greater. The average change in pain scores in the treatment group was 2.6 points (p 0.000) versus negligible change (p= 0.4) for the control group. Conclusion: The results show that CLRT is effective at immediately reducing chronic musculoskeletal pain. Further studies are needed with additional outcome measures to.« less

Psychophysics, flare, and neurosecretory function in human pain models: capsaicin versus electrically evoked pain.

PubMed

Geber, Christian; Fondel, Ricarda; Krämer, Heidrun H; Rolke, Roman; Treede, Rolfe-Detlef; Sommer, Claudia; Birklein, Frank

2007-06-01

Intradermal capsaicin injection (CAP) and electrical current stimulation (ES) are analyzed in respect to patterns and test-retest reliability of pain as well as sensory and neurosecretory changes. In 10 healthy subjects, 2x CAP (50 microg) and 2x ES (5 to 30 mA) were applied to the volar forearm. The time period between 2 identical stimulations was about 4 months. Pain ratings, areas of mechanical hyperalgesia, and allodynia were assessed. The intensity of sensory changes was quantified by using quantitative sensory testing. Neurogenic flare was assessed by using laser Doppler imaging. Calcitonin gene-related peptide (CGRP) release was quantified by dermal microdialysis in combination with an enzyme immunoassay. Time course and peak pain ratings were different between CAP and ES. Test-retest correlation was high (r > or = 0.73). Both models induced primary heat hyperalgesia and primary plus secondary pin-prick hyperalgesia. Allodynia occurred in about half of the subjects. Maximum flare sizes did not differ between CAP and ES, but flare intensities were higher for ES. Test-retest correlation was higher for flare sizes than for flare intensity. A significant CGRP release could only be measured after CAP. The different time courses of pain stimulation (CAP: rapidly decaying pain versus ES: pain plateau) led to different peripheral neurosecretory effects but induced similar central plasticity and hyperalgesia. The present study gives a detailed overview of psychophysical and neurosecretory characteristics induced by noxious stimulation with capsaicin and electrical current. We describe differences, similarities, and reproducibility of these human pain models. These data might help to interpret past and future results of human pain studies using experimental pain.

[Laser biostimulation in the treatment of pleurisy].

PubMed

Milojević, Momir; Kuruc, Vesna

2003-01-01

Low-intensity lasers have been utilized in medicine in two ways: for local stimulation and for stimulation of acupuncture points. Literature data reveal that this method has been indiscriminately applied in psychiatry, rheumatology, gynecology, dermatology, otorhinolaryngology, in diverse acute and chronic pains, inflammations, vascular disorders, angina pectoris, bronchial asthma. Most commonly reported clinical effects are analgesia, spasmolytic and anti-inflammatory effects, as well as faster wound and bone healing. This prospective study analyses effects of laser biostimulation on patients with pleurisy. The analysis included 25 patients treated at the Institute of Lung Diseases in Sremska Kamenica during 2000, 2001 and 2002. Apart from conservative treatment, these patients were treated with laser biostimulation of acupuncture points and local region for ten days. During treatment, changes of present clinical signs, general symptoms, radiological findings, as well as changes of some relevant biochemical parameters were recorded. Results were compared with the control group which included the same number of patients, who differed from the examined group only by not being exposed to laser biostimulation. The examined group of patients with pleuritis presented with quicker resorption of pleural effusion, less pleural adhesions, more significant decrease of clinical symptoms, especially pain, as well as more significant increase of cortisol and immunoglobulin A and decrease of circulating immune complexes (CIC), leukocytes and sedimentation rate than the control group. Mechanisms of laser biostimulation in treatment of pleurisy were described in detail and the obtained results were correlated to those reported by other authors. 1. Patients with pleurisy undergoing laser stimulation presented with faster resorption of effusion and remission of the subjective symptoms, as well as significant decrease of biochemical acute inflammation parameters in the peripheral blood and therefore with faster recovery. 2. In patients with pleurisy laser treatment increases regenerative mechanisms of the pleural surface, thus decreasing the quantity of formed adhesions and resulting in better mobility of the diaphragm.

Cerebral responses and role of the prefrontal cortex in conditioned pain modulation: an fMRI study in healthy subjects

PubMed Central

Bogdanov, Volodymyr B.; Viganò, Alessandro; Noirhomme, Quentin; Bogdanova, Olena V.; Guy, Nathalie; Laureys, Steven; Renshaw, Perry F.; Dallel, Radhouane; Phillips, Christophe; Schoenen, Jean

2017-01-01

The mechanisms underlying conditioned pain modulation (CPM) are multifaceted. We searched for a link between individual differences in prefrontal cortex activity during multi-trial heterotopic noxious cold conditioning and modulation of the cerebral response to phasic heat pain. In 24 healthy female subjects, we conditioned laser heat stimuli to the left hand by applying alternatively ice-cold or lukewarm compresses to the right foot. We compared pain ratings with cerebral fMRI BOLD responses. We also analyzed the relation between CPM and BOLD changes produced by the heterotopic cold conditioning itself, as well as the impact of anxiety and habituation of cold-pain ratings. Specific cerebral activation was identified in precuneus and left posterior insula/SII, respectively, during early and sustained phases of cold application. During cold conditioning, laser pain decreased (n = 7), increased (n = 10) or stayed unchanged (n = 7). At the individual level, the psychophysical effect was directly proportional to the cold-induced modulation of the laser-induced BOLD response in left posterior insula/SII. The latter correlated with the BOLD response recorded 80 s earlier during the initial 10-s phase of cold application in anterior cingulate, orbitofrontal and lateral prefrontal cortices. High anxiety and habituation of cold pain were associated with greater laser heat-induced pain during heterotopic cold stimulation. The habituation was also linked to the early cold-induced orbitofrontal responses. We conclude that individual differences in conditioned pain modulation are related to different levels of prefrontal cortical activation by the early part of the conditioning stimulus, possibly due to different levels in trait anxiety. PMID:25461267

Treatment of TMJDS with helium-neon laser beam irradiation on the acupoints

NASA Astrophysics Data System (ADS)

Li, Ping

1993-03-01

Through He-NE laser stimulation of acupuncture points, we treated and observed 50 cases of Temporomandibular Joint Dysfunction Syndrome (TMJDS). The results proved that this treatment was very effective for relieving the patient's pain. In cases which had structural disturbances and organic damage such as limitation of mouth-opening and joint clink, there was less improvement of symptoms and no relief for joint clink.

An ICON Overview on Physical Modalities for Neck Pain and Associated Disorders

PubMed Central

Graham, Nadine; Gross, Anita R; Carlesso, Lisa C; Santaguida, P. Lina; MacDermid, Joy C; Walton, Dave; Ho, Enoch

2013-01-01

Introduction: Neck pain is common, can be disabling and is costly to society. Physical modalities are often included in neck rehabilitation programs. Interventions may include thermal, electrotherapy, ultrasound, mechanical traction, laser and acupuncture. Definitive knowledge regarding optimal modalities and dosage for neck pain management is limited. Purpose: To systematically review existing literature to establish the evidence-base for recommendations on physical modalities for acute to chronic neck pain. Methods: A comprehensive computerized and manual search strategy from January 2000 to July 2012, systematic review methodological quality assessment using AMSTAR, qualitative assessment using a GRADE approach and recommendation presentation was included. Systematic or meta-analyses of studies evaluating physical modalities were eligible. Independent assessment by at least two review team members was conducted. Data extraction was performed by one reviewer and checked by a second. Disagreements were resolved by consensus. Results: Of 103 reviews eligible, 20 were included and 83 were excluded. Short term pain relief - Moderate evidence of benefit: acupuncture, intermittent traction and laser were shown to be better than placebo for chronic neck pain. Moderate evidence of no benefit: pulsed ultrasound, infrared light or continuous traction was no better than placebo for acute whiplash associated disorder, chronic myofascial neck pain or subacute to chronic neck pain. There was no added benefit when hot packs were combined with mobilization, manipulation or electrical muscle stimulation for chronic neck pain, function or patient satisfaction at six month follow-up. Conclusions: The current state of the evidence favours acupuncture, laser and intermittent traction for chronic neck pain. Some electrotherapies show little benefit for chronic neck pain. Consistent dosage, improved design and long term follow-up continue to be the recommendations for future research. PMID:24155804

Gender Differences in Laser Acupuncture—Results of a Crossover Study with Green and Yellow Laser at the Ear Point Shenmen

PubMed Central

Litscher, Daniela; Wang, Junying; Li, Guangzong; Bosch, Peggy; Wang, Lu

2018-01-01

Background: One of the most commonly used auricular acupuncture points selected for different pain treatment regimens is Shenmen. This point on the ear has been recognized as having a wide number of applications, as found by scientific investigation. Methods: Within this crossover study, the ear acupoint Shenmen was stimulated with two different kinds of laser (green, 532 nm and yellow, 589 nm) in 22 healthy volunteers (13 female, 9 male; mean age ± SD = 25.3 ± 4.1 years; range 21–36 years). Both green and yellow lasers were used for 15 min in the same volunteers in two different sessions. Results: The most prominent finding was that systolic blood pressure decreased significantly (p = 0.048) after yellow laser stimulation. Heart rate also decreased significantly (p < 0.001), whereas heart rate variability ratio low frequency (LF)/high frequency (HF) (p < 0.001) increased. The effects were significantly more pronounced in females than in males. In addition, the temperature was measured, and temperature increases were demonstrated at different locations on the ear using imaging methods. Conclusions: This study shows evidence of the effect of auricular laser acupuncture. However, a comparison with other publications was impossible because this is the first study using green and yellow laser stimulation on the ear. PMID:29543742

Age-related changes in laser-evoked potentials following trigeminal and hand stimulation in healthy subjects.

PubMed

de Tommaso, M; Ricci, K; Montemurno, A; Vecchio, E

2017-07-01

This study aimed to evaluate age-related changes in laser-evoked potential (LEP) features, including habituation, via trigeminal and hand stimulation in a large group of healthy volunteers. We recorded the LEPs by right-hand stimulation in 237 healthy subjects and by stimulation of the right supraorbital zone in 170 cases. The subjects ranged in age from 7 to 72 years and were divided into six groups by age. At the trigeminal level, the N2 and P2 latencies were significantly shorter and the N2-P2 amplitude was significantly larger in the 7-17 age group than in the other groups. The N2-P2 amplitude of the responses evoked by hand stimulation was significantly larger in the 7-40 age range than in the older subjects. The N1 amplitude and latency were not significantly different among the groups. The N2-P2 habituation increased with age, but no significant changes among groups were revealed by the Bonferroni test. Trigeminal vertex LEPs have greater amplitudes and appear earlier in children, while a progressive age-related amplitude decrease characterizes the N2-P2 waves associated with hand stimulation. The N2-P2 habituation increases in older people. The N1 latency and amplitude seem to remain stable during ageing and are therefore potentially reliable and useful patterns for nociceptive system examination. Standardization of age-related changes in trigeminal and hand LEPs is possible and should improve their reliability in the objective assessment of pain pathways. © 2017 European Pain Federation - EFIC®.

Laser stimulating ST36 with optical fiber induce blood component changes in mice: a Raman spectroscopy study.

PubMed

Zhang, Heng; Chen, Zhenyi; Wu, Jiping; Chen, Na; Xu, Wenjie; Li, Taihao; Liu, Shupeng

2018-02-15

ST36 is a commonly-used acupoint in traditional Chinese medicine (TCM) for treatment of inflammations, pains and gastrointestinal disturbs. For decades, the low power laser acupuncture has been widely applied as an alternative therapy to traditional metal needle acupuncture and achieved relatively fine therapeutic effect for ST36-related symptoms with reduction of uncomfortableness and infection risks. However its disadvantages of low penetrativity and lack of manipulation skills limit its potential performance. An optical fiber laser acupuncture introduced by the previous study combines traditional needling acupuncture and the laser stimulation together, making a stronger therapeutic effect and showing a potential value in clinical application. To evaluate its acupunctural effect on blood, mice are taken as experimental model and Raman spectroscopic technique is used to analysis the changes of blood components after stimulating on ST36. The results show that both the traditional needling acupuncture and optical fiber acupuncture could lead to some spectral changes of blood in mice. This study explores the optical fiber acupuncture's effect on blood in mice using Raman spectroscopy technique for mechanism of acupuncture therapy. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Future of laser biostimulation in America today: microlight 830

NASA Astrophysics Data System (ADS)

Smith, Chadwick F.; Vangsness, C. Thomas

1992-06-01

For the last two years we have been investigating the use of a 830 nanometer laser for low level laser therapy in chronic pain syndromes. This laser is of low energy and by definition is low level therapy (a laser output which does not exceed 100 milliwatts). This wave length has been carefully selected to be in the 'window' of wavelengths between 650 and 900 nanometers. At this level, the laser energy will penetrate the epidermis, the dermis and the subcutaneous layers to the deep tissue. The tissue effect of this laser energy is not thermal but rather a stimulation of micro-circulation with a secondary effect of blocking pain enzymes and activation of the synthesis of endorphin enzymes. We have experience with approximately 75 patients who have been treated with low level laser therapy. We have engaged in a double- blind study at several General Motors facilities in Michigan to determine the effectiveness of low level laser therapy in this inflammatory condition. Repetitive injuries in the work place have moved from 18% of industrial accidents in 1981 to 52% in 1989. Carpal Tunnel Syndrome is the number one economic problem in occupational medicine. It is true that 15% of the employees of American automotive plants have Carpal Tunnel Syndrome. This large number of patients have been treated in the past by standard physiotherapy treatment modalities and ultimately by surgery for failure of conservative therapy. Incidence of 'return to work activities' has been low. We intend to show that low level laser therapy may afford a positive solution to this problem not only therapeutically but prophylactically. Indications for treatment are Chronic Pain Syndrome and Carpal Tunnel Syndrome of mild to moderate degree.

Benefits of low-power lasers on oral soft tissue

NASA Astrophysics Data System (ADS)

Eduardo, Carlos d. P.; Cecchini, Silvia C. M.; Cecchini, Renata C.

1996-04-01

The last five years have represented a great advance in relation to laser development. Countries like Japan, United States, French, England, Israel and others, have been working on the association of researches and clinical applications, in the field of laser. Low power lasers like He-Ne laser, emitting at 632,8 nm and Ga-As-Al laser, at 790 nm, have been detached acting not only as a coadjutant but some times as an specific treatment. Low power lasers provide non thermal effect at wavelengths believed to stimulate circulation and cellular activity. These lasers have been used to promote wound healing and reduce inflammation edema and pain. This work presents a five year clinical study with good results related to oral tissue healing. Oral cavity lesions, like herpes and aphthous ulcers were irradiated with Ga-Al- As laser. In both cases, an excellent result was obtained. The low power laser application decrease the painful sintomatology immediately and increase the reparation process of these lesions. An excellent result was obtained with application of low power laser in herpetic lesions associated with a secondary infection situated at the lip commissure covering the internal tissue of the mouth. The healing occurred after one week. An association of Ga-Al-As laser and Nd:YAG laser have been also proven to be good therapy for these kind of lesions. This association of low and high power laser has been done since 1992 and it seems to be a complement of the conventional therapies.

Effect of low-level laser therapy on pain and perineal healing after episiotomy: A triple-blind randomized controlled trial.

PubMed

Alvarenga, Marina B; de Oliveira, Sonia Maria Junqueira Vasconcellos; Francisco, Adriana A; da Silva, Flora Maria B; Sousa, Marcelo; Nobre, Moacyr Roberto

2017-02-01

Episiotomy is associated with perineal pain and healing complications. The low-level laser therapy (LLLT) reduces pain and inflammation and stimulates the healing process. This study aimed to assess the effect of LLLT on pain and perineal healing after an episiotomy. A randomized, triple-blind, parallel clinical trial with 54 postpartum women who had a spontaneous birth with a right mediolateral episiotomy. The women were randomized into two groups: the experimental group (applications of LLLT n = 29) or the placebo group (simulated LLLT applications n = 25). Three sessions of real or sham irradiation were performed at 6-10 hours after normal birth, and the 2nd and 3rd applications were performed at 20-24 hours and 40-48 hours after the first session, respectively. Perineal pain was recorded using a Numeric Scale ranging from 0 to 10 (0 = absence and 10 = worst pain). Perineal healing was assessed using the redness, oedema, ecchymosis, discharge, and approximation (REEDA) scale. Both groups were assessed four times: in each of the three LLLT sessions and at 7-10 days after normal birth. The groups were compared using the Student's t, Mann-Whitney, and Chi-square tests. There was no significant difference between the groups regarding perineal healing after LLLT. The perineal pain scores were statistically higher in the experimental group in the first assessment and after the third LLLT. There was no significant difference between the groups related to the perineal pain scores 7-10 days after normal birth. The use of LLLT does not provide any benefit for treating postpartum perineal trauma using these specific protocol and parameters. Lasers Surg. Med. 49:181-188, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Finite element method simulating temperature distribution in skin induced by 980-nm pulsed laser based on pain stimulation.

PubMed

Wang, Han; Dong, Xiao-Xi; Yang, Ji-Chun; Huang, He; Li, Ying-Xin; Zhang, Hai-Xia

2017-07-01

For predicting the temperature distribution within skin tissue in 980-nm laser-evoked potentials (LEPs) experiments, a five-layer finite element model (FEM-5) was constructed based on Pennes bio-heat conduction equation and the Lambert-Beer law. The prediction results of the FEM-5 model were verified by ex vivo pig skin and in vivo rat experiments. Thirty ex vivo pig skin samples were used to verify the temperature distribution predicted by the model. The output energy of the laser was 1.8, 3, and 4.4 J. The laser spot radius was 1 mm. The experiment time was 30 s. The laser stimulated the surface of the ex vivo pig skin beginning at 10 s and lasted for 40 ms. A thermocouple thermometer was used to measure the temperature of the surface and internal layers of the ex vivo pig skin, and the sampling frequency was set to 60 Hz. For the in vivo experiments, nine adult male Wistar rats weighing 180 ± 10 g were used to verify the prediction results of the model by tail-flick latency. The output energy of the laser was 1.4 and 2.08 J. The pulsed width was 40 ms. The laser spot radius was 1 mm. The Pearson product-moment correlation and Kruskal-Wallis test were used to analyze the correlation and the difference of data. The results of all experiments showed that the measured and predicted data had no significant difference (P > 0.05) and good correlation (r > 0.9). The safe laser output energy range (1.8-3 J) was also predicted. Using the FEM-5 model prediction, the effective pain depth could be accurately controlled, and the nociceptors could be selectively activated. The FEM-5 model can be extended to guide experimental research and clinical applications for humans.

Pain hypersensitivity in congenital blindness is associated with faster central processing of C-fibre input.

PubMed

Slimani, H; Plaghki, L; Ptito, M; Kupers, R

2016-10-01

We have recently shown that visual deprivation from birth exacerbates responses to painful thermal stimuli. However, the mechanisms underlying pain hypersensitivity in congenital blindness are unclear. To study the contribution of Aδ- and C-fibres in pain perception, we measured thresholds and response times to selective C- and Aδ-fibre activation in congenitally blind, late blind and normally sighted participants. Ultrafast constant-temperature heat pulses were delivered to the hand with a CO2 laser using an interleaved adaptive double staircase procedure. Participants were instructed to respond as quickly as possible when detecting a laser-induced sensation. We used a 650 ms cut-off criterion to distinguish fast Aδ- from slow C-fibre-mediated sensations. Congenitally blind participants showed significantly faster reaction times to C- but not to Aδ-fibre-mediated sensations. In contrast, thresholds for Aδ- and C-fibre stimulation did not differ between groups. Late blind individuals did not differ from sighted controls in any aspect. A follow-up experiment using only suprathreshold stimuli for Aδ- and C-fibre activation confirmed these findings and further showed that congenitally blind individuals detected significantly more C-fibre-mediated stimuli than sighted controls. A decomposition analysis of the reaction times indicated that the faster response times in the congenitally blind are due to more efficient central processing of C-fibre-mediated sensations. The increased sensitivity to painful thermal stimulation in congenital blindness may be due to more efficient central processing of C-fibre-mediated input, which may help to avoid impending dangerous encounters with stimuli that threaten the bodily integrity. WHAT DOES THIS STUDY ADD?: Hypersensitivity to heat pain in congenital blindness is associated with faster responses to C-fibre activation, likely caused by more efficient central processing of C-fibre-mediated input. © 2016 European Pain Federation - EFIC®

Comparative effectiveness of Low Level Laser therapy and Transcutaneous Electric Nerve Stimulation on Temporomandibular Joint Disorders.

PubMed

Seifi, Massoud; Ebadifar, Asghar; Kabiri, Sattar; Badiee, Mohammad Reza; Abdolazimi, Zahra; Amdjadi, Parisa

2017-01-01

Introduction: Temporomandibular joint disorders (TMDs) are the most common source of pain on the face. There are multiple etiologies, and several types of treatment have been reported. The use of non-invasive and reversible therapies in the treatment of such problems is recommended. The present study evaluated the effect of low-level laser (LLL) therapy and transcutaneous electric nerve stimulation (TENS) on TMDs. Methods: In this single-blind study, 40 patients with temporomandibular disorders were randomly divided into four groups: TENS (TENSTem dental), LLL (diode 810 nm CW), shamTENS, and sham-LLL. All subjects were examined and data on pain and tenderness in the temporomandibular joint (TMJ) and masticatory muscles (using the visual analogue scale) and mouth-opening (distance between incisal edges before feeling pain; mm) were collected before baseline (T1), after each session (T2-T5) and one month after the end of the sessions (T6)), and analyzed using repeated measure analysis of variance (ANOVA) and Bonferroni statistical tests. A P value < 0.05 was considered significant. Results: The decrease in pain ( P =0.000), tenderness ( P =0.000) and increase in mouth-opening ability ( P =0.002) was greater in the TENS and LLL groups than in the placebo groups. At the one-month follow-up, significant decrease in pain and tenderness was recorded in the TENS and LLL groups ( P =0.000). There was no significant differences between TENS and LLL and the placebo groups for maximum mouth-opening at the end of the study ( P =0.692). Conclusion: Using TENS or LLL therapy can improve TMD symptoms at least for the short term. Although the effects of the placebo played a role in improving symptoms, their effects were less important.

Comparative effectiveness of Low Level Laser therapy and Transcutaneous Electric Nerve Stimulation on Temporomandibular Joint Disorders

PubMed Central

Seifi, Massoud; Ebadifar, Asghar; Kabiri, Sattar; Badiee, Mohammad Reza; Abdolazimi, Zahra; Amdjadi, Parisa

2017-01-01

Introduction: Temporomandibular joint disorders (TMDs) are the most common source of pain on the face. There are multiple etiologies, and several types of treatment have been reported. The use of non-invasive and reversible therapies in the treatment of such problems is recommended. The present study evaluated the effect of low-level laser (LLL) therapy and transcutaneous electric nerve stimulation (TENS) on TMDs. Methods: In this single-blind study, 40 patients with temporomandibular disorders were randomly divided into four groups: TENS (TENSTem dental), LLL (diode 810 nm CW), shamTENS, and sham-LLL. All subjects were examined and data on pain and tenderness in the temporomandibular joint (TMJ) and masticatory muscles (using the visual analogue scale) and mouth-opening (distance between incisal edges before feeling pain; mm) were collected before baseline (T1), after each session (T2-T5) and one month after the end of the sessions (T6)), and analyzed using repeated measure analysis of variance (ANOVA) and Bonferroni statistical tests. A P value < 0.05 was considered significant. Results: The decrease in pain (P=0.000), tenderness (P=0.000) and increase in mouth-opening ability (P=0.002) was greater in the TENS and LLL groups than in the placebo groups. At the one-month follow-up, significant decrease in pain and tenderness was recorded in the TENS and LLL groups (P=0.000). There was no significant differences between TENS and LLL and the placebo groups for maximum mouth-opening at the end of the study (P=0.692). Conclusion: Using TENS or LLL therapy can improve TMD symptoms at least for the short term. Although the effects of the placebo played a role in improving symptoms, their effects were less important PMID:29071032

Photochemical mechanisms of biological action of low-intensity laser irradiation

NASA Astrophysics Data System (ADS)

Klebanov, Gennady I.; Poltanov, Evgeny A.

2004-08-01

Low-intensity laser irradiation (LILI) is effectively used in clinical practice but the mechanisms of its stimulating action are still far from being understood completely and considered in the scientific literature only hypothetically. The main effects of LILI proved both in clinics and in experiments are bactericidal effect, vasodilatation, improved microcirculation, formation and growth of new microvessels, acceleration of wound healing, relieving of pain syndrome. We put forward a free radical conception underlying these effects. In this paper the experimental evidences of this conception is considered.

C-fiber-related EEG-oscillations induced by laser radiant heat stimulation of capsaicin-treated skin

PubMed Central

Domnick, Claudia; Hauck, Michael; Casey, Kenneth L; Engel, Andreas K; Lorenz, Jürgen

2009-01-01

Nociceptive input reaches the brain via two different types of nerve fibers, moderately fast A-delta and slowly conducting C-fibers, respectively. To explore their distinct roles in normal and inflammatory pain we used laser stimulation of normal and capsaicin treated skin at proximal and distal arm sites in combination with time frequency transformation of electroencephalography (EEG) data. Comparison of phase-locked (evoked) and non-phase-locked (total) EEG to laser stimuli revealed three significant pain-related oscillatory responses. First, an evoked response in the delta-theta band, mediated by A-fibers, was reduced by topical capsaicin treatment. Second, a decrease of total power in the alpha-to-gamma band reflected both an A- and C-nociceptor-mediated response with only the latter being reduced by capsaicin treatment. Finally, an enhancement of total power in the upper beta band was mediated exclusively by C-nociceptors and appeared strongly augmented by capsaicin treatment. These findings suggest that phase-locking of brain activity to stimulus onset is a critical feature of A-delta nociceptive input, allowing rapid orientation to salient and potentially threatening events. In contrast, the subsequent C-nociceptive input exhibits clearly less phase coupling to the stimulus. It may primarily signal the tissue status allowing more long-term behavioral adaptations during ongoing inflammatory events that accompany tissue damage. PMID:21197293

Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring.

PubMed

Avci, Pinar; Gupta, Asheesh; Sadasivam, Magesh; Vecchio, Daniela; Pam, Zeev; Pam, Nadav; Hamblin, Michael R

2013-03-01

Low-level laser (light) therapy (LLLT) is a fast-growing technology used to treat a multitude of conditions that require stimulation of healing, relief of pain and inflammation, and restoration of function. Although skin is naturally exposed to light more than any other organ, it still responds well to red and near-infrared wavelengths. The photons are absorbed by mitochondrial chromophores in skin cells. Consequently, electron transport, adenosine triphosphate nitric oxide release, blood flow, reactive oxygen species increase, and diverse signaling pathways are activated. Stem cells can be activated, allowing increased tissue repair and healing. In dermatology, LLLT has beneficial effects on wrinkles, acne scars, hypertrophic scars, and healing of burns. LLLT can reduce UV damage both as a treatment and as a prophylactic measure. In pigmentary disorders such as vitiligo, LLLT can increase pigmentation by stimulating melanocyte proliferation and reduce depigmentation by inhibiting autoimmunity. Inflammatory diseases such as psoriasis and acne can also be managed. The noninvasive nature and almost complete absence of side effects encourage further testing in dermatology.

Evaluation of Low-Level Laser Therapy in TMD Patients

PubMed Central

Emir, Faruk; Sahin, Cem

2015-01-01

Light amplification by stimulated emission of radiation (laser) is one of the most recent treatment modalities in dentistry. Low-level laser therapy (LLLT) is suggested to have biostimulating and analgesic effects through direct irradiation without causing thermal response. There are few studies that have investigated the efficacy of laser therapy in temporomandibular disorders (TMD), especially in reduced mouth opening. The case report here evaluates performance of LLLT with a diode laser for temporomandibular clicking and postoperative findings were evaluated in two cases of TMD patients. First patient had a history of limited mouth opening and pain in temporomandibular joint (TMJ) region since nine months. Second patient's main complaint was his restricted mouth opening, which was progressed in one year. LLLT was performed with a 685 nm red probed diode laser that has an energy density of 6.2 J/cm2, three times a week for one month, and application time was 30 seconds (685 nm, 25 mW, 30 s, 0.02 Hz, and 6.2 J/cm2) (BTL-2000, Portative Laser Therapy Device). The treatment protocol was decided according to the literature. One year later patients were evaluated and there were no changes. This application suggested that LLLT is an appropriate treatment for TMD related pain and limited mouth opening and should be considered as an alternative to other methods. PMID:26587294

Auricular Acupuncture with Laser

PubMed Central

Bahr, Frank

2013-01-01

Auricular acupuncture is a method which has been successfully used in various fields of medicine especially in the treatment of pain relief. The introduction of lasers especially low-level lasers into medicine brought besides the already existing stimulation with needles and electricity an additional technique to auricular acupuncture. This literature research looks at the historical background, the development and the anatomical and neurological aspects of auricular acupuncture in general and auricular laser acupuncture in detail. Preliminary scientific findings on auricular acupuncture with laser have been described in detail and discussed critically in this review article. The results of the studies have shown evidence of the effect of auricular laser acupuncture. However, a comparison of these studies was impossible due to their different study designs. The most important technical as well as study parameters were described in detail in order to give more sufficient evidence and to improve the quality of future studies. PMID:23935695

Physician perceptions of the value of physical modalities in the treatment of musculoskeletal disease.

PubMed

Rush, P J; Shore, A

1994-06-01

We randomly surveyed 100 specialists in rehabilitation medicine and 100 rheumatologists concerning their perceptions of the value of 11 different physical modalities--cold, active and passive exercise, interferential current, laser, magnetotherapy, microwave, shortwave diathermy, traction, ultrasound and transcutaneous nerve stimulation in the treatment of seven different musculoskeletal conditions--acute arthritis, joint contracture, neck pain, back pain, tendinitis, reflex sympathetic dystrophy and frozen shoulder. There were significant differences in the perceived benefits of modalities which varied by modality and condition. Overall, rehabilitation medicine specialists regarded modalities to be helpful more often than rheumatologists (P < 0.001).

The use of planarians as in vivo animal model to study laser biomodulation effects

NASA Astrophysics Data System (ADS)

Munin, Egberto; Garcia, Neila Maria Rocha; Braz, Allison Gustavo; de Souza, Sandra Cristina; Alves, Leandro Procópio; Salgado, Miguel Angel Castillo; Pilla, Viviane

2007-02-01

A variety of effects is attributed to the photo stimulation of tissues, such as improved healing of ulcers, analgesic and anti-inflammatory effects, stimulation of the proliferation of cells of different origins and stimulation of bone repair. Some investigations that make qualitative evaluations, like wound healing and evaluation of pain and edema, can be conducted in human subjects. However, deeper investigations on the mechanisms of action of the light stimulus and other quantitative works that requires biopsies or destructive analysis has to be carried out in animal models or in cell cultures. In this work, we propose the use of planarians as a model to study laser-tissue interaction. Contrasting with cell cultures and unicellular organisms, planarians are among the simplest organism having tissue layers, central nerve system, digestive and excretory system that might have been platforms for the evolution of the complex and highly organized tissues and organs found in higher organisms. For the present study, 685 nm laser radiation was employed. Planarians were cut transversally, in a plane posterior to the auricles. The body fragments were left to regenerate and the proliferation dynamics of stem cells was studied by using histological analysis. Maximum cell count was obtained for the laser treated group at the 4 th experimental day. At that experimental time, we also had the largest difference between the irradiated and the non-irradiated control group. We concluded that the studied flatworm could be an interesting animal model for in vivo studies of laser-tissue interactions.

Effect of laser acupuncture versus traditional acupuncture in neck pain of cervical spondylosis

NASA Astrophysics Data System (ADS)

El-Kharbotly, Ahmed M.; El-Gendy, Alyaa A.; Mohammed, Mouchira A.; El-Masry, Manal R.; Daoud, Eitedal M.; Hassan, Nagwa; Abdel-Wahab, Khaled G.; Helmy, Ghada; Mostafa, Taymour

2014-02-01

This prospective cohort study aimed to compare the efficiency of laser versus traditional acupuncture in treating cervical spondylosis (CS) pain. Forty female patients were randomized into two equal groups that received 3 sessions / week for 4 weeks. Group A received needle acupuncture therapy with electrical stimulation for 20 min at standard acupoints, ear points and Ashi point on the average 3 points. Group B received low level laser therapy (LLLT) acupuncture at the same acupoints. The results demonstrated that tenderness disappeared in 65% of patients in group A and 75% of patients in group B with improved percentage of 85.5% and 89.2%. Pain on VAS related to direction of motion at 6 directions was improved in all cases where with improvement percentage 76.45% and 85.88%. Pain on VAS at rest was improved in all patients with improvement percentage of 80.41% and 84.28%. NDIQ score improved in all patients with improvement percentage of 69.78% and 73.77%. Follow up of VAS after 6 months from the last session revealed persistent improvement in 55% of patients of group A vs 80% of patients of group B. Mean serum TNF-α was decreased in 85% of patients of group A vs 95% of patients of group B where serum beta endorphins was increased in all patients. It is concluded that both modes of treatment for CS gave improvement regarding pain intensity, disability and quality of life being more evident in LLLT followed for 6 months supported with improved serum TNFα and beta endorphin.

Effect of sympathetic activity on capsaicin-evoked pain, hyperalgesia, and vasodilatation.

PubMed

Baron, R; Wasner, G; Borgstedt, R; Hastedt, E; Schulte, H; Binder, A; Kopper, F; Rowbotham, M; Levine, J D; Fields, H L

1999-03-23

Painful nerve and tissue injuries can be exacerbated by activity in sympathetic neurons. The mechanisms of sympathetically maintained pain (SMP) are unclear. To determine the effect of cutaneous sympathetic activity on pain induced by primary afferent C-nociceptor sensitization with capsaicin in humans. In healthy volunteers capsaicin was applied topically (n = 12) or injected into the forearm skin (n = 10) to induce spontaneous pain, dynamic and punctate mechanical hyperalgesia, and antidromic (axon reflex) vasodilatation (flare). Intensity of pain and hyperalgesia, axon reflex vasodilatation (laser Doppler), and flare size and area of hyperalgesia (planimetry) were assessed. The local skin temperature at the application and measurement sites was kept constant at 35 degrees C. In each individual the analyses were performed during the presence of high and low sympathetic skin activity induced by whole-body cooling and warming with a thermal suit. By this method sympathetic vasoconstrictor activity is modulated in the widest range that can be achieved physiologically. The degree of vasoconstrictor discharge was monitored by measuring skin blood flow (laser Doppler) and temperature (infrared thermometry) at the index finger. The intensity and spatial distribution of capsaicin-evoked spontaneous pain and dynamic and punctate mechanical hyperalgesia were identical during the presence of high and low sympathetic discharge. Antidromic vasodilatation and flare size were significantly diminished when sympathetic vasoconstrictor neurons were excited. Cutaneous sympathetic vasoconstrictor activity does not influence spontaneous pain and mechanical hyperalgesia after capsaicin-induced C-nociceptor sensitization. When using physiologic stimulation of sympathetic activity, the capsaicin model is not useful for elucidating mechanisms of SMP. In neuropathic pain states with SMP, different mechanisms may be present.

Anthropogenic Radio-Frequency Electromagnetic Fields Elicit Neuropathic Pain in an Amputation Model

PubMed Central

Jones, Erick; Romero-Ortega, Mario

2016-01-01

Anecdotal and clinical reports have suggested that radio-frequency electromagnetic fields (RF EMFs) may serve as a trigger for neuropathic pain. However, these reports have been widely disregarded, as the epidemiological effects of electromagnetic fields have not been systematically proven, and are highly controversial. Here, we demonstrate that anthropogenic RF EMFs elicit post-neurotomy pain in a tibial neuroma transposition model. Behavioral assays indicate a persistent and significant pain response to RF EMFs when compared to SHAM surgery groups. Laser thermometry revealed a transient skin temperature increase during stimulation. Furthermore, immunofluorescence revealed an increased expression of temperature sensitive cation channels (TRPV4) in the neuroma bulb, suggesting that RF EMF-induced pain may be due to cytokine-mediated channel dysregulation and hypersensitization, leading to thermal allodynia. Additional behavioral assays were performed using an infrared heating lamp in place of the RF stimulus. While thermally-induced pain responses were observed, the response frequency and progression did not recapitulate the RF EMF effects. In vitro calcium imaging experiments demonstrated that our RF EMF stimulus is sufficient to directly contribute to the depolarization of dissociated sensory neurons. Furthermore, the perfusion of inflammatory cytokine TNF-α resulted in a significantly higher percentage of active sensory neurons during RF EMF stimulation. These results substantiate patient reports of RF EMF-pain, in the case of peripheral nerve injury, while confirming the public and scientific consensus that anthropogenic RF EMFs engender no adverse sensory effects in the general population. PMID:26760033

A new diode laser acupuncture therapy apparatus

NASA Astrophysics Data System (ADS)

Li, Chengwei; Huang, Zhen; Li, Dongyu; Zhang, Xiaoyuan

2006-06-01

Since the first laser-needles acupuncture apparatus was introduced in therapy, this kind of apparatus has been well used in laser biomedicine as its non-invasive, pain- free, non-bacterium, and safetool. The laser acupuncture apparatus in this paper is based on single-chip microcomputer and associated by semiconductor laser technology. The function like traditional moxibustion including reinforcing and reducing is implemented by applying chaos method to control the duty cycle of moxibustion signal, and the traditional lifting and thrusting of acupuncture is implemented by changing power output of the diode laser. The radiator element of diode laser is made and the drive circuit is designed. And chaos mathematic model is used to produce deterministic class stochastic signal to avoid the body adaptability. This function covers the shortages of continuous irradiation or that of simple disciplinary stimulate signal, which is controlled by some simple electronic circuit and become easily adjusted by human body. The realization of reinforcing and reducing of moxibustion is technological innovation in traditional acupuncture coming true in engineering.

Affective touch and attachment style modulate pain: a laser-evoked potentials study

PubMed Central

Drabek, Marianne M.; Paloyelis, Yannis; Fotopoulou, Aikaterini

2016-01-01

Affective touch and cutaneous pain are two sub-modalities of interoception with contrasting affective qualities (pleasantness/unpleasantness) and social meanings (care/harm), yet their direct relationship has not been investigated. In 50 women, taking into account individual attachment styles, we assessed the role of affective touch and particularly the contribution of the C tactile (CT) system in subjective and electrophysiological responses to noxious skin stimulation, namely N1 and N2-P2 laser-evoked potentials. When pleasant, slow (versus fast) velocity touch was administered to the (non-CT-containing) palm of the hand, higher attachment anxiety predicted increased subjective pain ratings, in the same direction as changes in N2 amplitude. By contrast, when pleasant touch was administered to CT-containing skin of the arm, higher attachment anxiety predicted attenuated N1 and N2 amplitudes. Higher attachment avoidance predicted opposite results. Thus, CT-based affective touch can modulate pain in early and late processing stages (N1 and N2 components), with the direction of effects depending on attachment style. Affective touch not involving the CT system seems to affect predominately the conscious perception of pain, possibly reflecting socio-cognitive factors further up the neurocognitive hierarchy. Affective touch may thus convey information about available social resources and gate pain responses depending on individual expectations of social support. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’. PMID:28080967

Interactions Between Dyspnea and the Brain Processing of Nociceptive Stimuli: Experimental Air Hunger Attenuates Laser-Evoked Brain Potentials in Humans.

PubMed

Dangers, Laurence; Laviolette, Louis; Similowski, Thomas; Morélot-Panzini, Capucine

2015-01-01

Dyspnea and pain share several characteristics and certain neural networks and interact with each other. Dyspnea-pain counter-irritation consists of attenuation of preexisting pain by intercurrent dyspnea and has been shown to have neurophysiological correlates in the form of inhibition of the nociceptive spinal reflex RIII and laser-evoked potentials (LEPs). Experimentally induced exertional dyspnea inhibits RIII and LEPs, while "air hunger" dyspnea does not inhibit RIII despite its documented analgesic effects. We hypothesized that air hunger may act centrally and inhibit LEPs. LEPs were obtained in 12 healthy volunteers (age: 21-29) during spontaneous breathing (FB), ventilator-controlled breathing (VC) tailored to FB, after inducing air hunger by increasing the inspired fraction of carbon dioxide -FiCO2- (VCCO2), and during ventilator-controlled breathing recovery (VCR). VCCO2 induced intense dyspnea (visual analog scale = 63% ± 6% of full scale, p < 0.001 vs. VC), predominantly of the air hunger type. VC alone reduced the amplitude of the N2-P2 component of LEPs (Δ = 24.0% ± 21.1%, p < 0.05, effect-size = 0.74) predominantly through a reduction in P2, and the amplitude of this inhibition was further reduced by inducting air hunger (Δ = 22.6% ± 17.9%, p < 0.05, effect-size = 0.53), predominantly through a reduction in N2. Somatosensory-evoked potentials (SEPs) were not affected by VC or VCCO2, suggesting that the observed effects are specific to pain transmission. We conclude that air hunger interferes with the cortical mechanisms responsible for the cortical response to painful laser skin stimulation, which provides a neurophysiological substrate to the central nature of its otherwise documented analgesic effects.

Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring

PubMed Central

Avci, Pinar; Gupta, Asheesh; Sadasivam, Magesh; Vecchio, Daniela; Pam, Zeev; Pam, Nadav; Hamblin, Michael R

2013-01-01

Low-level laser (light) therapy (LLLT) is a fast-growing technology used to treat a multitude of conditions that require stimulation of healing, relief of pain and inflammation, and restoration of function. Although the skin is the organ that is naturally exposed to light more than any other organ, it still responds well to red and near-infrared wavelengths. The photons are absorbed by mitochondrial chromophores in skin cells. Consequently electron transport, adenosine triphosphate (ATP) nitric oxide release, blood flow, reactive oxygen species increase and diverse signaling pathways get activated. Stem cells can be activated allowing increased tissue repair and healing. In dermatology, LLLT has beneficial effects on wrinkles, acne scars, hypertrophic scars, and healing of burns. LLLT can reduce UV damage both as a treatment and as a prophylaxis. In pigmentary disorders such as vitiligo, LLLT can increase pigmentation by stimulating melanocyte proliferation and reduce depigmentation by inhibiting autoimmunity. Inflammatory diseases such as psoriasis and acne can also benefit. The non-invasive nature and almost complete absence of side-effects encourages further testing in dermatology. PMID:24049929

Effect of GaAs Laser at 904 nm in the Pain Threshold in Tibia and Tolerance in Deltoid Evaluated by Pressure Algometry

NASA Astrophysics Data System (ADS)

Soares, Luiz G. P.; Sato, Sidney K.; Silveira, Landulfo; Aimbire, Flávio; Moreira, Leonardo M.; Pinheiro, Antônio L. B.

2011-08-01

The use of LLLT in pain relief is a controversial issue in Physiotherapy, with the efficacy of LLLT associated to pain relief still requiring significant study. Objective. This work focuses on the evaluation of the effect of low power GaAs laser at 904 nm in pressure pain threshold and tolerance in tibia and deltoid muscle, respectively. A total of 17 subjects were divided in two groups: active and sham laser. Measurements were taken before and after laser irradiation in healthy individuals using a pressure algometry, first verifying the viability of algometry to evaluate the pain threshold and tolerance inter individuals and comparing the differences of right and left sides in the same patients, and finally evaluating the pain threshold and tolerance before and after a single laser application. Laser energy density was of 4.0 J/cm2 with power density of 137 mW/cm2. Comparing algometry values of active laser group and the sham group, the pain tolerance in the deltoid muscle did not change among groups after laser irradiation, while it was also encountered a statistically significant difference in the pain threshold in tibia when comparing the laser active and sham laser (p<0.05). It was found that the active laser was effective in maintaining the pain threshold in tibia. The effective laser action in raising the pain threshold in tibia upon healthy individuals can suggest that the laser could be applied not only as curative but also with preventive purpose.

The role of pain catastrophizing in experimental pain perception.

PubMed

Kristiansen, Frederik L; Olesen, Anne E; Brock, Christina; Gazerani, Parisa; Petrini, Laura; Mogil, Jeffrey S; Drewes, Asbjørn M

2014-03-01

Pain is a subjective experience influenced by multiple factors, and tremendous variety within individuals is present. To evaluate emotional state of pain, catastrophizing score can be used. This study investigated pain catastrophizing ratings in association with experimental pain perception. Experimental pain was induced using thermal heat and cold stimulation of skin, mechanical stimulation of muscle and bone, and thermal, mechanical, and electrical stimulation of the gastrointestinal tract in healthy participants (N = 41). Prior to experimental sessions, a pain catastrophizing questionnaire was filled out by each participant. Based on the median catastophizing score, participants were divided into two groups: noncatastrophizers and low-catastrophizers. No significant difference was found between low-catastrophizers and noncatastrophizers in thermal heat stimulation of skin, mechanical stimulation of muscle and bone, and rectal electrical stimulation (All P > 0.05). Low-catastrophizers were more sensitive to visceral thermal stimulation (4.7%, P = 0.02) and visceral mechanical stimulation (29.7%, P = 0.03). For participants that completed the 120 seconds ice water stimulation, noncatastrophizers reported 13.8% less pain than low-catastrophizers (P = 0.02). A positive correlation between PCS score and pain perception on cold pressor test was found (r = 0.4, P = 0.02). By extrapolating data, further analysis of the total group was performed and no differences (both P > 0.05) were observed. Even small increments in pain catastrophizing score can influence pain perception to deep and tonic stimulations. Catatrophizing may partly explain the variability found in experimental pain studies. © 2013 World Institute of Pain.

21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral nerve...

Enhanced control of electrochemical response in metallic materials in neural stimulation electrode applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, K.G.; Steen, W.M.; Manna, I.

New means have been investigated for the production of electrode devices (stimulation electrodes) which could be implanted in the human body in order to control pain, activate paralysed limbs or provide electrode arrays for cochlear implants for the deaf or for the relief of tinitus. To achieve this ion implantation and laser materials processing techniques were employed. Ir was ion implanted in Ti-6Al-4V alloy and the surface subsequently enriched in the noble metal by dissolution in sulphuric acid. For laser materials processing techniques, investigation has been carried out on the laser cladding and laser alloying of Ir in Ti wire.more » A particular aim has been the determination of conditions required for the formation of a two phase Ir, Ir-rich, and Ti-rich microstructure which would enable subsequent removal of the non-noble phase to leave a highly porous noble metal with large real surface area and hence improved charge carrying capacity compared with conventional non porous electrodes. Evaluation of the materials produced has been carried out using repetitive cyclic voltammetry, amongst other techniques. For laser alloyed Ir on Ti wire, it has been found that differences in the melting point and density of the materials makes control of the cladding or alloying process difficult. Investigation of laser process parameters for the control of alloying and cladding in this system was carried out and a set of conditions for the successful production of two phase Ir-rich and Ti-rich components in a coating layer with strong metallurgical bonding to the Ti alloy substrate was derived. The laser processed material displays excellent potential for further development in providing stimulation electrodes with the current carrying capacity of Ir but in a form which is malleable and hence capable of formation into smaller electrodes with improved spatial resolution compared with presently employed electrodes.« less

Elevation of pain threshold by vaginal stimulation in women.

PubMed

Whipple, B; Komisaruk, B R

1985-04-01

In 2 studies with 10 women each, vaginal self-stimulation significantly increased the threshold to detect and tolerate painful finger compression, but did not significantly affect the threshold to detect innocuous tactile stimulation. The vaginal self-stimulation was applied with a specially designed pressure transducer assembly to produce a report of pressure or pleasure. In the first study, 6 of the women perceived the vaginal stimulation as producing pleasure. During that condition, the pain tolerance threshold increased significantly by 36.8% and the pain detection threshold increased significantly by 53%. A second study utilized other types of stimuli. Vaginal self-stimulation perceived as pressure significantly increased the pain tolerance threshold by 40.3% and the pain detection threshold by 47.4%. In the second study, when the vaginal stimulation was self-applied in a manner that produced orgasm, the pain tolerance threshold and pain detection threshold increased significantly by 74.6% and 106.7% respectively, while the tactile threshold remained unaffected. A variety of control conditions, including various types of distraction, did not significantly elevate pain or tactile thresholds. We conclude that in women, vaginal self-stimulation decreases pain sensitivity, but does not affect tactile sensitivity. This effect is apparently not due to painful or non-painful distraction.

Biostimulation effect of low-level laser on healing process after third molar surgery, based on biochemical markers in saliva

NASA Astrophysics Data System (ADS)

Kroulikova, Veronika; Dostálová, Tatjana; Podzimek, Stepan

2015-02-01

Third molar extractions in general anesthesia have become a standard procedure in dentistry. There is an effort to shorten healing time and decrease the number of complications as well as increase comfort after the treatment. Low-level lasers are known for their analgesic, anti-inflammatory, and stimulatory effect. The aim of the study is to evaluate the effect of low-level laser after surgery in general anesthesia reducing the patient's discomfort, i.e. mainly pain, and also, to monitor the biostimulation process. Our study included 79 patients treated at the Department of Maxilofacial Surgery, diagnosed with third molar retention. Diode low-level laser radiation (wavelength 830 nm, output power 270 mW, probe aperture of 6.4 mm2) with dose ~ 3 mJ was applied. The control group was treated by using placebo - red light. The exposure time was 11 seconds immediately after the suture; the treatment was repeated every day for the following 3 days. To evaluate the effect of laser biostimulation, the objective markers for immunological determination of healing - sIgA and lysozyme in non-stimulated saliva of patients - were used. The sIgA decreases after laser application from 546.91 mg/l to 304. 91mg/l and in the control group from 602.25mg/l to 425.62 mg/l. The results were statistically significant. The level of lysozyme decreases from 54.27 mg/l to 2.45mg/l after laser biostimulation, from 304.371mg/l to 11.08mg/l after placebo effect. The study has confirmed a low-level laser healing effect not directly related to pain.

Burst spinal cord stimulation evaluated in patients with failed back surgery syndrome and painful diabetic neuropathy.

PubMed

de Vos, Cecile C; Bom, Marjanne J; Vanneste, Sven; Lenders, Mathieu W P M; de Ridder, Dirk

2014-02-01

Spinal cord stimulation (SCS) is used for treating intractable neuropathic pain. Generally, it induces paresthesia in the area covered by SCS. Burst SCS was introduced as a new stimulation paradigm with good pain relief without causing paresthesia. Good results have been obtained in patients who were naive to SCS. In this study we assess the effectiveness of burst stimulation in three groups of chronic pain patients who are already familiar with SCS and the accompanying paresthesia. Forty-eight patients with at least six months of conventional, tonic stimulation tested burst stimulation for a period of two weeks. They were classified in three different groups: a cross-section of our population with painful diabetic neuropathy (PDN), a cross-section of our population with failed back surgery syndrome (FBSS), and FBSS patients who over time had become poor responders (PR) to SCS. Visual analog scale scores for pain were assessed prior to implantation, with tonic stimulation, and after two weeks of burst stimulation. Burst stimulation reduced pain significantly for almost all patients. When compared with tonic stimulation, burst stimulation led to a significant additional pain reduction of on average 44% in patients with PDN (p < 0.001) and 28% in patients with FBSS (p < 0.01). Patients from the PR group benefitted less from burst stimulation on average. In addition, burst stimulation caused little or no paresthesia whereas tonic stimulation did induce paresthesia. Most patients preferred burst stimulation, but several preferred tonic stimulation because the paresthesia assured them that the SCS was working. About 60% of the patients with tonic SCS experienced further pain reduction upon application of burst stimulation. © 2013 International Neuromodulation Society.

Low-energy laser biostimulation therapy of musculoskeletal disorders: clinical study

NASA Astrophysics Data System (ADS)

Filonenko, Natalia; Livshitz, Oleg; Salansky, Norman M.

1992-06-01

215 patients (86 males and 129 females, average age 60.3 years) suffering from musculoskeletal and neuromuscular disorders, both chronic and acute, were treated by low energy lasers. Most patients failed to improve in spite of the fact that different conventional treatment modalities were implemented. Some of them were unable to tolerate drugs because of allergy or gastrointestinal intolerance. The photobiostimulation system FABULIGHTTM (IMM Inc., Canada) with adjustable output parameters for both red and infrared wavelength was used. Different modalities of LELBT were used: local and generalized stimulation of tender points and affected areas. Stiffness, swelling, range of motion and pain were assessed. 65% of symptoms improvement was obtained in average.

Do intensity ratings and skin conductance responses reliably discriminate between different stimulus intensities in experimentally induced pain?

PubMed

Breimhorst, Markus; Sandrock, Stephan; Fechir, Marcel; Hausenblas, Nadine; Geber, Christian; Birklein, Frank

2011-01-01

The present study addresses the question whether pain-intensity ratings and skin conductance responses (SCRs) are able to detect different intensities of phasic painful stimuli and to determine the reliability of this discrimination. For this purpose, 42 healthy participants of both genders were assigned to either electrical, mechanical, or laser heat-pain stimulation (each n = 14). A whole range of single brief painful stimuli were delivered on the right volar forearm of the dominant hand in a randomized order. Pain-intensity ratings and SCRs were analyzed. Using generalizability theory, individual and gender differences were the main contributors to the variability of both intensity ratings and SCRs. Most importantly, we showed that pain-intensity ratings are a reliable measure for the discrimination of different pain stimulus intensities in the applied modalities. The reliability of SCR was adequate when mechanical and heat stimuli were tested but failed for the discrimination of electrical stimuli. Further studies are needed to reveal the reason for this lack of accuracy for SCRs when applying electrical pain stimuli. Our study could help researchers to better understand the relationship between pain and activation of the sympathetic nervous system. Pain researchers are furthermore encouraged to consider individual and gender differences when measuring pain intensity and the concomitant SCRs in experimental settings. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Objective correlate of subjective pain perception by contact heat-evoked potentials.

PubMed

Granovsky, Yelena; Granot, Michal; Nir, Rony-Reuven; Yarnitsky, David

2008-01-01

The method of pain-evoked potentials has gained considerable acceptance over the last 3 decades regarding its objectivity, repeatability, and quantifiability. The present study explored whether the relationship between pain-evoked potentials and pain psychophysics obtained by contact heat stimuli is similar to those observed for the conventionally used laser stimulation. Evoked potentials (EPs) were recorded in response to contact heat stimuli at different body sites in 24 healthy volunteers. Stimuli at various temperatures were applied to the forearm (43 degrees C, 46 degrees C, 49 degrees C, and 52 degrees C) and leg (46 degrees C and 49 degrees C). The amplitudes of both components (N2 and P2) were strongly associated with the intensity of the applied stimuli and with subjective pain perception. Yet, regression analysis revealed pain perception and not stimulus intensity as the major contributing factor. A significant correlation was found between the forearm and the leg for both psychophysics and EPs amplitude. Contact heat can generate readily distinguishable evoked potentials on the scalp, consistent between upper and lower limbs. Although these potentials bear positive correlation with both stimulus intensity and pain magnitude, the latter is the main contributor to the evoked brain response.

Low-level laser therapy for pain relief after episiotomy: a double-blind randomised clinical trial.

PubMed

Santos, Jaqueline de O; de Oliveira, Sonia M J V; da Silva, Flora M B; Nobre, Moacyr R C; Osava, Ruth H; Riesco, Maria L G

2012-12-01

To evaluate the effectiveness of a low-level laser therapy for pain relief in the perineum following episiotomy during childbirth. Laser irradiation is a painless and non-invasive therapy for perineal pain treatment and its effects have been investigated in several studies, with no clear conclusion on its effectiveness. A double-blind randomised controlled clinical trial. One hundred and fourteen women who underwent right mediolateral episiotomies during vaginal birth in an in-hospital birthing centre in São Paulo, Brazil and reported pain ≥ 3 on a numeric scale (0-10) were randomised into three groups of 38 women each: two experimental groups (treated with red and infrared laser) and a control group. The experimental groups were treated with laser applied at three points directly on the episiotomy after suturing in a single session between 6-56 hours postpartum. We used a diode laser with wavelengths of 660 nm (red laser) and 780 nm (infrared laser). The control group participants underwent all laser procedures, excluding the emission of irradiation. The participants and the pain scores evaluator were blinded to the type of intervention. The perineal pain scores were assessed at three time points: before, immediately after and 30 minutes after low-level laser therapy. The comparison of perineal pain between the three groups showed no significant differences in the three evaluations (p = 0.445), indicating that the results obtained in the groups treated with low-level laser therapy were equivalent to the control group. Low-level laser therapy did not decrease the intensity of perineal pain reported by women who underwent right mediolateral episiotomy. The effect of laser in perineal pain relief was not demonstrated in this study. The dosage may not have been sufficient to provide relief from perineal pain after episiotomy during a vaginal birth. © 2012 Blackwell Publishing Ltd.

Electroencephalographic evoked pain response is suppressed by spinal cord stimulation in complex regional pain syndrome: a case report.

PubMed

Hylands-White, Nicholas; Duarte, Rui V; Beeson, Paul; Mayhew, Stephen D; Raphael, Jon H

2016-12-01

Pain is a subjective response that limits assessment. The purpose of this case report was to explore how the objectivity of the electroencephalographic response to thermal stimuli would be affected by concurrent spinal cord stimulation. A patient had been implanted with a spinal cord stimulator for the management of complex regional pain syndrome of both hands for 8 years. Following ethical approval and written informed consent we induced thermal stimuli using the Medoc PATHWAY Pain & Sensory Evaluation System on the right hand of the patient with the spinal cord stimulator switched off and with the spinal cord stimulator switched on. The patient reported a clinically significant reduction in thermal induced pain using the numerical rating scale (71.4 % reduction) with spinal cord stimulator switched on. Analysis of electroencephalogram recordings indicated the occurrence of contact heat evoked potentials (N2-P2) with spinal cord stimulator off, but not with spinal cord stimulator on. This case report suggests that thermal pain can be reduced in complex regional pain syndrome patients with the use of spinal cord stimulation and offers objective validation of the reported outcomes with this treatment.

Treatment of FBSS Low Back Pain with a Novel Percutaneous DRG Wireless Stimulator: Pilot and Feasibility Study.

PubMed

Weiner, Richard L; Yeung, Anthony; Montes Garcia, Carlos; Tyler Perryman, Laura; Speck, Benjamin

2016-10-01

Test a miniaturized neurostimulator transforaminally placed at the dorsal root ganglion (DRG) and evaluate the device's safety and efficacy in treating failed back surgery syndrome (FBSS) low back pain. Pilot, two-phase study. Eleven subjects with chronic intractable neuropathic trunk and/or lower limbs pain were included. The system consisted of an implantable, miniaturized stimulator, provided by Stimwave Technologies (Freedom-4) and an external transmitter. Only one stimulator per subject was implanted unilaterally and transforaminally at L1 to L5 levels. During Phase 1 of the study, the stimulators were not anchored. In Phase 2, the stimulators were anchored. Subjects were treated during 45 days after which the stimulator was removed. Pain reduction, implant duration, and stimulator migration were registered. Overall pain reduction was 59.9%, with only one device placed at one location, covering only a portion of the painful areas in the majority of the subjects. In Phase 1, the non-anchored stimulators migrated a mean of 8.80 mm and in Phase 2 a mean of 1.83 mm. Stimulator migration did not correlate with changes in pain relief. Mean time-to-implant duration was 10 minutes and no adverse events were reported during implant, follow-up period, or after explant. The pain reduction results indicate that the Freedom-4 spinal cord stimulation (SCS) Wireless System is a viable treatment of low back pain through stimulation of the DRG, and better overall pain reduction may be achieved by implanting multiple devices. With short percutaneous implant times and excellent safety profile, this new system may offer health cost savings. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Referred pain and cutaneous responses from deep tissue electrical pain stimulation in the groin.

PubMed

Aasvang, E K; Werner, M U; Kehlet, H

2015-08-01

Persistent postherniotomy pain is located around the scar and external inguinal ring and is often described as deep rather than cutaneous, with frequent complaints of pain in adjacent areas. Whether this pain is due to local pathology or referred/projected pain is unknown, hindering mechanism-based treatment. Deep tissue electrical pain stimulation by needle electrodes in the right groin (rectus muscle, ilioinguinal/iliohypogastric nerve and perispermatic cord) was combined with assessment of referred/projected pain and the cutaneous heat pain threshold (HPT) at three prespecified areas (both groins and the lower right arm) in 19 healthy subjects. The assessment was repeated 10 days later to assess the reproducibility of individual responses. Deep electrical stimulation elicited pain at the stimulation site in all subjects, and in 15 subjects, pain from areas outside the stimulation area was reported, with 90-100% having the same response on both days, depending on the location. Deep pain stimulation significantly increased the cutaneous HPT (P<0.014). Individual HPT responses before and during deep electrical pain stimulation were significantly correlated (ρ>0.474, P≤0.040) at the two test days for the majority of test areas. Our results corroborate a systematic relationship between deep pain and changes in cutaneous nociception. The individual referred/projected pain patterns and cutaneous responses are variable, but reproducible, supporting individual differences in anatomy and sensory processing. Future studies investigating the responses to deep tissue electrical stimulation in persistent postherniotomy pain patients may advance our understanding of underlying pathophysiological mechanisms and strategies for treatment and prevention. ClinicalTrials.gov (NCT01701427). © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evoked pain analgesia in chronic pelvic pain patients using respiratory-gated auricular vagal afferent nerve stimulation.

PubMed

Napadow, Vitaly; Edwards, Robert R; Cahalan, Christine M; Mensing, George; Greenbaum, Seth; Valovska, Assia; Li, Ang; Kim, Jieun; Maeda, Yumi; Park, Kyungmo; Wasan, Ajay D

2012-06-01

Previous vagus nerve stimulation (VNS) studies have demonstrated antinociceptive effects, and recent noninvasive approaches, termed transcutaneous-vagus nerve stimulation (t-VNS), have utilized stimulation of the auricular branch of the vagus nerve in the ear. The dorsal medullary vagal system operates in tune with respiration, and we propose that supplying vagal afferent stimulation gated to the exhalation phase of respiration can optimize t-VNS. Counterbalanced, crossover study. Patients with chronic pelvic pain (CPP) due to endometriosis in a specialty pain clinic. INTERVENTIONS/OUTCOMES: We evaluated evoked pain analgesia for respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) compared with nonvagal auricular stimulation (NVAS). RAVANS and NVAS were evaluated in separate sessions spaced at least 1 week apart. Outcome measures included deep-tissue pain intensity, temporal summation of pain, and anxiety ratings, which were assessed at baseline, during active stimulation, immediately following stimulation, and 15 minutes after stimulus cessation. RAVANS demonstrated a trend for reduced evoked pain intensity and temporal summation of mechanical pain, and significantly reduced anxiety in N = 15 CPP patients, compared with NVAS, with moderate to large effect sizes (η(2) > 0.2). Chronic pain disorders such as CPP are in great need of effective, nonpharmacological options for treatment. RAVANS produced promising antinociceptive effects for quantitative sensory testing (QST) outcomes reflective of the noted hyperalgesia and central sensitization in this patient population. Future studies should evaluate longer-term application of RAVANS to examine its effects on both QST outcomes and clinical pain. Wiley Periodicals, Inc.

Cutaneous pain effects induced by Nd:YAG and CO2 laser stimuli

NASA Astrophysics Data System (ADS)

Wang, Jia-Rui; Yu, Guang-Yuan; Yang, Zai-Fu; Chen, Hong-Xia; Hu, Dong-Dong; Zou, Xian-Biao

2012-12-01

The near infrared laser technique can activate cutaneous nociceptors with high specificity and reproducibility and be used in anti-riot equipment. This study aimed to explore cutaneous pain effect and determine the threshold induced by Nd:YAG and CO2 laser stimuli. The corresponding wavelength was 1.32μm and 10.6μm. The pain effect was assessed in three healthy subjects (1 woman and 2 men) on the skin of dorsum of both hands. The energy of each pulse and whether the subjects felt a painful sensation after each stimulus were recorded. A simplified Bliss Method was used to calculate the pain threshold which were determined under three pulse durations for Nd:YAG laser and one pulse duration for CO2 laser. As a result the pain thresholds were determined to be 5.6J/cm2, 5.4J/cm2 and 5.0J/cm2 respectively when using Nd:YAG laser, 4.0mm beam diameter, 8ms, 0.1s and 1s pulse duration. The pain threshold was 1.0J/cm2 when using CO2 laser, 4.0mm beam diameter and 0.1s pulse duration. We concluded that the threshold of cutaneous pain elicited by 1.32μm laser was independent upon the pulse duration when the exposure time ranged from 8ms to 1s. Under the same exposure condition, the threshold of cutaneous pain elicited by 1.32μm laser was higher than that elicited by 10.6μm laser.

21 CFR 882.5880 - Implanted spinal cord stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Implanted spinal cord stimulator for pain relief. (a) Identification. An implanted spinal cord stimulator for pain relief is a device that is used to stimulate electrically a patient's spinal cord to relieve... on the patient's spinal cord and an external transmitter for transmitting the stimulating pulses...

Effect of low-level laser stimulation on EEG.

PubMed

Wu, Jih-Huah; Chang, Wen-Dien; Hsieh, Chang-Wei; Jiang, Joe-Air; Fang, Wei; Shan, Yi-Chia; Chang, Yang-Chyuan

2012-01-01

Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG) changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz) to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain.

PubMed

Moseley, G Lorimer; Zalucki, Nadia M; Wiech, Katja

2008-07-31

Chronic pain is often associated with reduced tactile acuity. A relationship exists between pain intensity, tactile acuity and cortical reorganisation. When pain resolves, tactile function improves and cortical organisation normalises. Tactile acuity can be improved in healthy controls when tactile stimulation is associated with a behavioural objective. We hypothesised that, in patients with chronic limb pain and decreased tactile acuity, discriminating between tactile stimuli would decrease pain and increase tactile acuity, but tactile stimulation alone would not. Thirteen patients with complex regional pain syndrome (CRPS) of one limb underwent a waiting period and then approximately 2 weeks of tactile stimulation under two conditions: stimulation alone or discrimination between stimuli according to their diameter and location. There was no change in pain (100 mm VAS) or two-point discrimination (TPD) during a no-treatment waiting period, nor during the stimulation phase (p > 0.32 for both). Pain and TPD were lower after the discrimination phase [mean (95% CI) effect size for pain VAS = 27 mm (14-40 mm) and for TPD = 5.7 mm (2.9-8. ), p < 0.015 for both]. These gains were maintained at three-month follow-up. We conclude that tactile stimulation can decrease pain and increase tactile acuity when patients are required to discriminate between the type and location of tactile stimuli.

Role of diode lasers in oro-facial pain management.

PubMed

Javed, F; Kellesarian, S V; Romanos, G E

2017-01-01

With the increasing use of low level laser therapy (LLLT) in clinical dentistry, the aim of the present study was to assess the effectiveness of diode lasers in the management of orofacial pain. Indexed databases were searched without language and time restrictions up to and including July 2016 using different combinations of the following key words: oral, low level laser therapy, dental, pain, diode lasers, discomfort and analgesia. From the literature reviewed it is evident that LLLT is effective compared to traditional procedures in the management of oro-facial pain associated to soft tissue and hard tissue conditions such as premalignant lesions, gingival conditions and dental extractions. However, it remains to be determined which particular wavelength will produce the more favorable and predictable outcome in terms of pain reduction. It is highly recommended that further randomized control trials with well-defined control groups should be performed to determine the precise wavelengths of the diode lasers for the management of oro-facial pain. Within the limits of the present review, it is concluded that diode lasers therapy is more effective in the management of oro-facial pain compared to traditional procedures.

Objective pain diagnostics: clinical neurophysiology.

PubMed

Garcia-Larrea, L

2012-06-01

Neurophysiological techniques help in diagnosis, prognosis and treatment of chronic pain, and are particularly useful to determine its neuropathic origin. According to current standards, the diagnosis of definite neuropathic pain (NP) needs objective confirmation of a lesion or disease of somatosensory systems, which can be provided by neurophysiological testing. Lesions causing NP mostly concern the pain-temperature pathways, and therefore neurophysiological procedures allowing the specific testing of these pathways (i.e., A-delta and C-fibres, spino-thalamo-cortical tracts) are essential for objective diagnosis. Different techniques to stimulate selectively pain-temperature pathways are discussed. Of these, laser-evoked potentials (LEPs) appear as the easiest and most reliable neurophysiological method of assessing nociceptive function, and their coupling with autonomic responses (e.g., galvanic skin response) and psychophysics (quantitative sensory testing - QST) can still enhance their diagnostic yield. Neurophysiological techniques not exploring specifically nociception, such as standard nerve conduction velocities (NCV) and SEPs to non-noxious stimulation, should be associated to the exploration of nociceptive systems, not only because both may be simultaneously affected to different degrees, but also because some specific painful symptoms, such as paroxysmal discharges, may depend on specific alteration of highly myelinated A-beta fibres. The choice of techniques is determined after anamnesis and clinical exam, and tries to answer a number of questions: (a) is the pain-related to injury of somatosensory pathways?; (b) to what extent are different subsystems affected?; (c) are mechanisms and lesion site in accordance with imaging data?; (d) are results of use for diagnostic or therapeutic follow-up? Neuropathic pain (NP) affects more than 15 million people in Western countries, and its belated diagnosis leads to insufficient or delayed therapy. The use of neurofunctional approaches to obtain a "physiological photograph" of somatosensory function is therefore highly relevant, as it yields significant clues about the type and mechanisms of pain, thus prompting rapid and optimised therapy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Targeted therapies using electrical and magnetic neural stimulation for the treatment of chronic pain in spinal cord injury.

PubMed

Moreno-Duarte, Ingrid; Morse, Leslie R; Alam, Mahtab; Bikson, Marom; Zafonte, Ross; Fregni, Felipe

2014-01-15

Chronic neuropathic pain is one of the most common and disabling symptoms in individuals with spinal cord injury (SCI). Over two-thirds of subjects with SCI suffer from chronic pain influencing quality of life, rehabilitation, and recovery. Given the refractoriness of chronic pain to most pharmacological treatments, the majority of individuals with SCI report worsening of this condition over time. Moreover, only 4-6% of patients in this cohort report improvement. Novel treatments targeting mechanisms associated with pain-maladaptive plasticity, such as electromagnetic neural stimulation, may be desirable to improve outcomes. To date, few, small clinical trials have assessed the effects of invasive and noninvasive nervous system stimulation on pain after SCI. We aimed to review initial efficacy, safety and potential predictors of response by assessing the effects of neural stimulation techniques to treat SCI pain. A literature search was performed using the PubMed database including studies using the following targeted stimulation strategies: transcranial Direct Current Stimulation (tDCS), High Definition tDCS (HD-tDCS), repetitive Transcranial Magnetical Stimulation (rTMS), Cranial Electrotherapy Stimulation (CES), Transcutaneous Electrical Nerve Stimulation (TENS), Spinal Cord Stimulation (SCS) and Motor Cortex Stimulation (MCS), published prior to June of 2012. We included studies from 1998 to 2012. Eight clinical trials and one naturalistic observational study (nine studies in total) met the inclusion criteria. Among the clinical trials, three studies assessed the effects of tDCS, two of CES, two of rTMS and one of TENS. The naturalistic study investigated the analgesic effects of SCS. No clinical trials for epidural motor cortex stimulation (MCS) or HD-tDCS were found. Parameters of stimulation and also clinical characteristics varied significantly across studies. Three out of eight studies showed larger effects sizes (0.73, 0.88 and 1.86 respectively) for pain reduction. Classical neuropathic pain symptoms such as dysesthesia (defined as an unpleasant burning sensation in response to touch), allodynia (pain due to a non-painful stimulus), pain in paroxysms, location of SCI in thoracic and lumbar segments and pain in the lower limbs seem to be associated with a positive response to neural stimulation. No significant adverse effects were reported in these studies. Chronic pain in SCI is disabling and resistant to common pharmacologic approaches. Electrical and magnetic neural stimulation techniques have been developed to offer a potential tool in the management of these patients. Although some of these techniques are associated with large standardized mean differences to reduce pain, we found an important variability in these results across studies. There is a clear need for the development of methods to decrease treatment variability and increase response to neural stimulation for pain treatment. We discuss potential methods such as neuroimaging or EEG-guided neural stimulation and the development of better surrogate markers of response such as TMS-indexed cortical plasticity. Copyright © 2013. Published by Elsevier Inc.

[Transcranial magnetic stimulation and motor cortex stimulation in neuropathic pain].

PubMed

Mylius, V; Ayache, S S; Teepker, M; Kappus, C; Kolodziej, M; Rosenow, F; Nimsky, C; Oertel, W H; Lefaucheur, J P

2012-12-01

Non-invasive and invasive cortical stimulation allows the modulation of therapy-refractory neuropathic pain. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the contralateral motor cortex yields therapeutic effects at short-term and predicts the benefits of epidural motor cortex stimulation (MCS). The present article summarizes the findings on application, mechanisms and therapeutic effects of cortical stimulation in neuropathic pain.

Effects of Transcranial Direct Current Stimulation (tDCS) on Pain Distress Tolerance: A Preliminary Study.

PubMed

Mariano, Timothy Y; van't Wout, Mascha; Jacobson, Benjamin L; Garnaat, Sarah L; Kirschner, Jason L; Rasmussen, Steven A; Greenberg, Benjamin D

2015-08-01

Pain remains a critical medical challenge. Current treatments target nociception without addressing affective symptoms. Medically intractable pain is sometimes treated with cingulotomy or deep brain stimulation to increase tolerance of pain-related distress. Transcranial direct current stimulation (tDCS) may noninvasively modulate cortical areas related to sensation and pain representations. The present study aimed to test the hypothesis that cathodal ("inhibitory") stimulation targeting left dorsal anterior cingulate cortex (dACC) would increase tolerance to distress from acute painful stimuli vs anodal stimulation. Forty healthy volunteers received both anodal and cathodal stimulation. During stimulation, we measured pain distress tolerance with three tasks: pressure algometer, cold pressor, and breath holding. We measured pain intensity with a visual-analog scale before and after each task. Mixed ANOVA revealed that mean cold pressor tolerance tended to be higher with cathodal vs anodal stimulation (P = 0.055) for participants self-completing the task. Pressure algometer (P = 0.81) and breath holding tolerance (P = 0.19) did not significantly differ. The pressure algometer exhibited a statistically significant order effect irrespective of stimulation polarity (all P < 0.008). Pain intensity ratings increased acutely after cold pressor and pressure algometer tasks (both P < 0.01), but not after breath holding (P = 0.099). Cold pressor pain ratings tended to rise less after cathodal vs anodal tDCS (P = 0.072). Although our primary results were nonsignificant, there is a preliminary suggestion that cathodal tDCS targeting left dACC may increase pain distress tolerance to cold pressor. Pressure algometer results are consistent with task-related sensitization. Future studies are needed to refine this novel approach for pain neuromodulation. Wiley Periodicals, Inc.

Fractional CO2 Laser: From Skin Rejuvenation to Vulvo-Vaginal Reshaping.

PubMed

Filippini, Maurizio; Del Duca, Ester; Negosanti, Francesca; Bonciani, Diletta; Negosanti, Luca; Sannino, Mario; Cannarozzo, Giovanni; Nisticò, Steven Paul

2017-03-01

The CO 2 laser has become the gold standard treatment in dermatologic surgery for the treatment of a large number of skin and mucosal lesions. The introduction of the fractional micro-ablative technology represented an integration to the ablative resurfacing technique, reducing the healing time and the side effects. Vaginal rejuvenation performed with this technique is a minimally invasive procedure that stimulates internal tissues of the female lower genital tract to regenerate the mucosa, improving tissue trophism and restoring the correct functionality. In our experience, 386 menopausal women affected with vulvo-vaginal atrophy (VVA) were treated with three section of fractional micro-ablative CO 2 laser. After three treatments, patients reported a complete improvement of the symptoms (59.94% dryness, 56.26% burn, sensation, 48.75% dyspareunia, 56.37% itch, 73.15% soreness, and 48.79% vaginal introitus pain). Fractional micro-ablative CO 2 laser seems to reduce symptoms related to vaginal atrophy. The beneficial effects were reported just after the first session and confirmed 12 months after the last session.

Triangular stimulation method utilizing combination spinal cord stimulation with peripheral subcutaneous field stimulation for chronic pain patients: a retrospective study.

PubMed

Navarro, Rosa M; Vercimak, Danika C

2012-01-01

This retrospective data collection study aims to evaluate the responses of patients who have been implanted with a neuromodulation system using a combination of spinal cord stimulation (SCS) and peripheral subcutaneous field stimulation (PSFS) leads for chronic intractable pain. Forty patients with chronic, intractable pain implanted with both SCS and PSFS leads were enrolled in a retrospective data collection study. Pre-implant data (demographics, pain levels, pain location, and medication use) and post-implant data (pain levels, medication use, and device programming reports) were compared to measure short- and long-term improvements in pain for a period of approximately six months. Device system use and parameter data were collected. The majority of patients experienced immediate and short-term pain relief and reduction in oral pain medications as a result of combination SCS/PSFS therapy. The improvements were maintained for some, but not all patients by six months. Patients cycled through multiple programs over follow-up; the use of triangular stimulation was consistent over time, and by six months, patients preferred this program over others. Limitations of the retrospective chart review included missing data and variable follow-up times, and may have made determinations of long-term efficacy difficult. This study demonstrates that combination SCS and PSFS therapy is potentially a beneficial treatment option for reducing pain levels and oral pain medication compared with baseline in previously resistive chronic pain patients. There is a need for further study of this therapy in a greater number of subjects and in a prospective, controlled setting. In the author's general experience, triangular stimulation is very effective for treating isolated low back pain, because it covers larger topographic areas of the lower back than flow or field stimulation. An investigational device exemption study will be necessary for subcutaneous field stimulation indicated for focal isolated pain to be adequately investigated and utilized by physicians in the future. © 2012 International Neuromodulation Society.

Thermal Detection Thresholds of Aδ- and C-Fibre Afferents Activated by Brief CO2 Laser Pulses Applied onto the Human Hairy Skin

PubMed Central

Churyukanov, Maxim; Plaghki, Léon; Legrain, Valéry; Mouraux, André

2012-01-01

Brief high-power laser pulses applied onto the hairy skin of the distal end of a limb generate a double sensation related to the activation of Aδ- and C-fibres, referred to as first and second pain. However, neurophysiological and behavioural responses related to the activation of C-fibres can be studied reliably only if the concomitant activation of Aδ-fibres is avoided. Here, using a novel CO2 laser stimulator able to deliver constant-temperature heat pulses through a feedback regulation of laser power by an online measurement of skin temperature at target site, combined with an adaptive staircase algorithm using reaction-time to distinguish between responses triggered by Aδ- and C-fibre input, we show that it is possible to estimate robustly and independently the thermal detection thresholds of Aδ-fibres (46.9±1.7°C) and C-fibres (39.8±1.7°C). Furthermore, we show that both thresholds are dependent on the skin temperature preceding and/or surrounding the test stimulus, indicating that the Aδ- and C-fibre afferents triggering the behavioural responses to brief laser pulses behave, at least partially, as detectors of a change in skin temperature rather than as pure level detectors. Most importantly, our results show that the difference in threshold between Aδ- and C-fibre afferents activated by brief laser pulses can be exploited to activate C-fibres selectively and reliably, provided that the rise in skin temperature generated by the laser stimulator is well-controlled. Our approach could constitute a tool to explore, in humans, the physiological and pathophysiological mechanisms involved in processing C- and Aδ-fibre input, respectively. PMID:22558230

Brain imaging of pain sensitization in patients with knee osteoarthritis.

PubMed

Pujol, Jesus; Martínez-Vilavella, Gerard; Llorente-Onaindia, Jone; Harrison, Ben J; López-Solà, Marina; López-Ruiz, Marina; Blanco-Hinojo, Laura; Benito, Pere; Deus, Joan; Monfort, Jordi

2017-09-01

A relevant aspect in osteoarthritic pain is neural sensitization. This phenomenon involves augmented responsiveness to painful stimulation and may entail a clinically worse prognosis. We used functional magnetic resonance imaging (fMRI) to study pain sensitization in patients with knee osteoarthritis. Sixty patients were recruited and pain sensitization was clinically defined on the basis of regional spreading of pain (spreading sensitization) and increased pain response to repeated stimulation (temporal summation). Functional magnetic resonance imaging testing involved assessing brain responses to both pressure and heat stimulation. Thirty-three patients (55%) showed regional pain spreading (simple sensitization) and 19 patients (32%) showed both regional spreading and temporal summation. Sensitized patients were more commonly women. Direct painful pressure stimulation of the joint (articular interline) robustly activated all of the neural elements typically involved in pain perception, but did not differentiate sensitized and nonsensitized patients. Painful pressure stimulation on the anterior tibial surface (sensitized site) evoked greater activation in sensitized patients in regions typically involved in pain and also beyond these regions, extending to the auditory, visual, and ventral sensorimotor cortices. Painful heat stimulation of the volar forearm did not discriminate the sensitization phenomenon. Results confirm the high prevalence of pain sensitization secondary to knee osteoarthritis. Relevantly, the sensitization phenomenon was associated with neural changes extending beyond strict pain-processing regions with enhancement of activity in general sensory, nonnociceptive brain areas. This effect is in contrast to the changes previously identified in primary pain sensitization in fibromyalgia patients presenting with a weakening of the general sensory integration.

Back pain: a real target for spinal cord stimulation?

PubMed

Rigoard, Philippe; Delmotte, Alexandre; D'Houtaud, Samuel; Misbert, Lorraine; Diallo, Bakari; Roy-Moreau, Aline; Durand, Sylvain; Royoux, Solène; Giot, Jean-Philippe; Bataille, Benoit

2012-03-01

Failed back surgery syndrome represents one of the most frequent etiologies of chronic back pain and is a major public health issue. Neurostimulation has currently not been validated in the treatment of back pain because of technological limitations in implantable spinal cord stimulation (SCS) systems. New-generation leads using several columns of stimulation can generate longitudinal and/or transverse stimulation fields into the spinal cord. To investigate, through extensive stimulation testing, the capacity of multicolumn tripolar leads to achieve back territory paresthesia coverage in refractory failed back surgery syndrome patients. Eleven patients implanted with a 16-contact spinal cord stimulation lead (Specify 5-6-5, Medtronic Inc) were assessed with a systematic exploration of 43 selected stimulation configurations to generate bilateral back paresthesia in addition to leg territory coverage. The tripolar lead successfully generated paresthesia in both bilateral back and leg territories in 9 patients (81.8%). Success rates of multicolumn stimulation patterns were significantly higher than for longitudinal configurations for lombodorsal paresthesia coverage. Six months after implantation, significant pain relief was obtained compared with preoperative evaluation for global pain (Visual Analog Scale, 2.25 vs 8.2 preoperatively; P < .05), leg pain (Visual Analog Scale, 0.5 vs 7.6 preoperatively; P < .05), and back pain (Visual Analog Scale, 1.5 vs 7.8 preoperatively; P < .05). These results suggest that multicolumn leads can reliably generate back pain coverage and favor pain relief outcomes. This may lead physicians to reconsider new indications for spinal cord stimulation. Expanding neurostimulation perspectives to intractable back pain syndromes could become realistic in the near future.

Effectiveness of transcranial direct current stimulation and visual illusion on neuropathic pain in spinal cord injury

PubMed Central

Kumru, Hatice; Pelayo, Raul; Vidal, Joan; Tormos, Josep Maria; Fregni, Felipe; Navarro, Xavier; Pascual-Leone, Alvaro

2010-01-01

The aim of this study was to evaluate the analgesic effect of transcranial direct current stimulation of the motor cortex and techniques of visual illusion, applied isolated or combined, in patients with neuropathic pain following spinal cord injury. In a sham controlled, double-blind, parallel group design, 39 patients were randomized into four groups receiving transcranial direct current stimulation with walking visual illusion or with control illusion and sham stimulation with visual illusion or with control illusion. For transcranial direct current stimulation, the anode was placed over the primary motor cortex. Each patient received ten treatment sessions during two consecutive weeks. Clinical assessment was performed before, after the last day of treatment, after 2 and 4 weeks follow-up and after 12 weeks. Clinical assessment included overall pain intensity perception, Neuropathic Pain Symptom Inventory and Brief Pain Inventory. The combination of transcranial direct current stimulation and visual illusion reduced the intensity of neuropathic pain significantly more than any of the single interventions. Patients receiving transcranial direct current stimulation and visual illusion experienced a significant improvement in all pain subtypes, while patients in the transcranial direct current stimulation group showed improvement in continuous and paroxysmal pain, and those in the visual illusion group improved only in continuous pain and dysaesthesias. At 12 weeks after treatment, the combined treatment group still presented significant improvement on the overall pain intensity perception, whereas no improvements were reported in the other three groups. Our results demonstrate that transcranial direct current stimulation and visual illusion can be effective in the management of neuropathic pain following spinal cord injury, with minimal side effects and with good tolerability. PMID:20685806

One-shot percutaneous electrical nerve stimulation vs. transcutaneous electrical nerve stimulation for low back pain: comparison of therapeutic effects.

PubMed

Hsieh, Ru-Lan; Lee, Wen-Chung

2002-11-01

To investigate the therapeutic effects of one shot of low-frequency percutaneous electrical nerve stimulation one shot of transcutaneous electrical nerve stimulation in patients with low back pain. In total, 133 low back pain patients were recruited for this randomized, control study. Group 1 patients received medication only. Group 2 patients received medication plus one shot of percutaneous electrical nerve stimulation. Group 3 patients received medication plus one shot of transcutaneous electrical nerve stimulation. Therapeutic effects were measured using a visual analog scale, body surface score, pain pressure threshold, and the Quebec Back Pain Disability Scale. Immediately after one-shot treatment, the visual analog scale improved 1.53 units and the body surface score improved 3.06 units in the percutaneous electrical nerve stimulation group. In the transcutaneous electrical nerve stimulation group, the visual analog scale improved 1.50 units and the body surface score improved 3.98 units. The improvements did not differ between the two groups. There were no differences in improvement at 3 days or 1 wk after the treatment among the three groups. Simple one-shot treatment with percutaneous electrical nerve stimulation or transcutaneous electrical nerve stimulation provided immediate pain relief for low back pain patients. One-shot transcutaneous electrical nerve stimulation treatment is recommended due to the rarity of side effects and its convenient application.

Temporal and spatial temperature distribution in the glabrous skin of rats induced by short-pulse CO2 laser

NASA Astrophysics Data System (ADS)

Lu, Pen-Li; Hsu, Shu-Shen; Tsai, Meng-Li; Jaw, Fu-Shan; Wang, An-Bang; Yen, Chen-Tung

2012-11-01

Pain is a natural alarm that aids the body in avoiding potential danger and can also present as an important indicator in clinics. Infrared laser-evoked potentials can be used as an objective index to evaluate nociception. In animal studies, a short-pulse laser is crucial because it completes the stimulation before escape behavior. The objective of the present study was to obtain the temporal and spatial temperature distributions in the skin caused by the irradiation of a short-pulse laser. A fast speed infrared camera was used to measure the surface temperature caused by a CO2 laser of different durations (25 and 35 ms) and power. The measured results were subsequently implemented with a three-layer finite element model to predict the subsurface temperature. We found that stratum corneum was crucial in the modeling of fast temperature response, and escape behaviors correlated with predictions of temperature at subsurface. Results indicated that the onset latency and duration of activated nociceptors must be carefully considered when interpreting physiological responses evoked by infrared irradiation.

Sandwich technique, peripheral nerve stimulation, peripheral field stimulation and hybrid stimulation for inguinal region and genital pain.

PubMed

Shaw, Andrew; Sharma, Mayur; Zibly, Zion; Ikeda, Daniel; Deogaonkar, Milind

2016-12-01

Ilioinguinal neuralgia (IG) and genitofemoral (GF) neuralgia following inguinal hernia repair is a chronic and debilitating neuropathic condition. Recently, peripheral nerve stimulation has become an effective and minimally invasive option for the treatment of refractory pain. Here we present a retrospective case series of six patients who underwent placement of peripheral nerve stimulation electrodes using various techniques for treatment of refractory post-intervention inguinal region pain. Six patients with post-intervention inguinal, femoral or GF neuropathic pain were evaluated for surgery. Either octopolar percutaneous electrodes or combination of paddle and percutaneous electrodes were implanted in the area of their pain. Pain visual analog scores (VAS), surgical complication rate, preoperative symptom duration, degree of pain relief, preoperative and postoperative work status, postoperative changes in medication usage, and overall degree of satisfaction with this therapy was assessed. All six patients had an average improvement of 62% in the immediate post-operative follow-up. Four patients underwent stimulation for IG, one for femoral neuralgia, and another for GF neuralgia. Peripheral nerve stimulation provided at least 50% pain relief in all the six patients with post-intervention inguinal region pain. 85% of patients indicated they were completely satisfied with the therapy overall. There was one treatment failure with an acceptable complication rate. Peripheral nerve or field stimulation for post-intervention inguinal region pain is a safe and effective treatment for this refractory and complex problem for patients who have exhausted other management options.

Evoked Pain Analgesia in Chronic Pelvic Pain Patients using Respiratory-gated Auricular Vagal Afferent Nerve Stimulation

PubMed Central

Napadow, Vitaly; Edwards, Robert R; Cahalan, Christine M; Mensing, George; Greenbaum, Seth; Valovska, Assia; Li, Ang; Kim, Jieun; Maeda, Yumi; Park, Kyungmo; Wasan, Ajay D.

2012-01-01

Objective Previous Vagus Nerve Stimulation (VNS) studies have demonstrated anti-nociceptive effects, and recent non-invasive approaches; termed transcutaneous-VNS, or t-VNS, have utilized stimulation of the auricular branch of the vagus nerve in the ear. The dorsal medullary vagal system operates in tune with respiration, and we propose that supplying vagal afferent stimulation gated to the exhalation phase of respiration can optimize t-VNS. Design counterbalanced, crossover study. Patients patients with chronic pelvic pain (CPP) due to endometriosis in a specialty pain clinic. Interventions/Outcomes We evaluated evoked pain analgesia for Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) compared with Non-Vagal Auricular Stimulation (NVAS). RAVANS and NVAS were evaluated in separate sessions spaced at least one week apart. Outcome measures included deep tissue pain intensity, temporal summation of pain, and anxiety ratings, which were assessed at baseline, during active stimulation, immediately following stimulation, and 15 minutes after stimulus cessation. Results RAVANS demonstrated a trend for reduced evoked pain intensity and temporal summation of mechanical pain, and significantly reduced anxiety in N=15 CPP patients, compared to NVAS, with moderate to large effect sizes (eta2>0.2). Conclusion Chronic pain disorders such as CPP are in great need of effective, non-pharmacological options for treatment. RAVANS produced promising anti-nociceptive effects for QST outcomes reflective of the noted hyperalgesia and central sensitization in this patient population. Future studies should evaluate longer-term application of RAVANS to examine its effects on both QST outcomes and clinical pain. PMID:22568773

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous electrical nerve stimulator for... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Transcutaneous electrical nerve stimulator for...

Pain Relief in CRPS-II after Spinal Cord and Motor Cortex Simultaneous Dual Stimulation.

PubMed

Lopez, William Oc; Barbosa, Danilo C; Teixera, Manoel J; Paiz, Martin; Moura, Leonardo; Monaco, Bernardo A; Fonoff, Erich T

2016-05-01

We describe a case of a 30-year-old woman who suffered a traumatic injury of the right brachial plexus, developing severe complex regional pain syndrome type II (CRPS-II). After clinical treatment failure, spinal cord stimulation (SCS) was indicated with initial positive pain control. However, after 2 years her pain progressively returned to almost baseline intensity before SCS. Additional motor cortex electrode implant was then proposed as a rescue therapy and connected to the same pulse generator. This method allowed simultaneous stimulation of the motor cortex and SCS in cycling mode with independent stimulation parameters in each site. At 2 years follow-up, the patient reported sustained improvement in pain with dual stimulation, reduction of painful crises, and improvement in quality of life. The encouraging results in this case suggests that this can be an option as add-on therapy over SCS as a possible rescue therapy in the management of CRPS-II. However, comparative studies must be performed in order to determine the effectiveness of this therapy. Chronic neuropathic pain, Complex regional pain syndrome Type II, brachial plexus injury, motor cortex stimulation, spinal cord stimulation.

Transcutaneous electrical nerve stimulation: nonparallel antinociceptive effects on chronic clinical pain and acute experimental pain.

PubMed

Cheing, G L; Hui-Chan, C W

1999-03-01

To investigate to what extent a single 60-minute session of transcutaneous electrical nerve stimulation (TENS) would modify chronic clinical pain, acute experimental pain, and the flexion reflex evoked in chronic low back pain patients. Thirty young subjects with chronic low back pain were randomly allocated to two groups, receiving either TENS or placebo stimulation to the lumbosacral region for 60 minutes. The flexion reflex was elicited by an electrical stimulation applied to the subject's right sole and recorded electromyographically from the biceps femoris and the tibialis anterior muscles. Subjective sensation of low back pain and the electrically induced pain were measured by two separate visual analog scales, termed VAS(LBP) and VAS(FR), respectively. Data obtained before, during, and 60 minutes after TENS and placebo stimulations were analyzed using repeated measures ANOVA. The VAS(LBP) score was significantly reduced to 63.1% of the prestimulation value after TENS (p<.001), but the reduction was negligible after placebo stimulation (to 96.7%, p = .786). In contrast, no significant change was found in the VASFR score (p = .666) and the flexion reflex area (p = .062) during and after stimulation within each group and between the two groups (p = .133 for VASFR and p = .215 for flexion reflex area). The same TENS protocol had different degrees of antinociceptive influence on chronic and acute pain in chronic low back pain patients.

Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome (CRPS) Recurrence after Amputation for CRPS, and Failure of Conventional Spinal Cord Stimulation.

PubMed

Goebel, Andreas; Lewis, Sarah; Phillip, Rhodri; Sharma, Manohar

2018-01-01

Limb amputation is sometimes being performed in long-standing complex regional pain syndrome (CRPS), although little evidence is available guiding management decisions, including how CRPS recurrence should be managed. This report details the management of a young soldier with CRPS recurrence 2 years after midtibial amputation for CRPS. Conventional spinal cord stimulation did not achieve paraesthetic coverage, or pain relief in the stump, whereas L4 dorsal root ganglion stimulation achieved both coverage and initially modest pain relief, and over time, substantial pain relief. Current evidence does not support the use of amputation to improve either pain or function in CRPS. Before a decision is made, in exceptional cases, about referral for amputation, dorsal root ganglion stimulation should be considered as a potentially effective treatment, even where conventional spinal cord stimulator treatment has failed to achieve reliable paraesthetic cover. Furthermore, this treatment may provide pain relief in those patients with CRPS recurrence in the stump after amputation. © 2017 World Institute of Pain.

21 CFR 882.5880 - Implanted spinal cord stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted spinal cord stimulator for pain relief. 882.5880 Section 882.5880 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Implanted spinal cord stimulator for pain relief. (a) Identification. An implanted spinal cord stimulator...

A functional magnetic resonance imaging study of human brain in pain-related areas induced by electrical stimulation with different intensities.

PubMed

Yuan, Wang; Ming, Zhang; Rana, Netra; Hai, Liu; Chen-wang, Jin; Shao-hui, Ma

2010-01-01

Pain-related studies have mainly been performed through traditional methods, which lack the rigorous analysis of anatomical locations. Functional magnetic resonance imaging (fMRI) is a noninvasive method detecting neural activity, and has the ability to precisely locate related activations in vivo. Moreover, few studies have used painful stimulation of changed intensity to investigate relevant functioning nuclei in the human brain. This study mainly focused on the pain-related activations induced by electrical stimulation with different intensities using fMRI. Furthermore, the electrophysiological characteristics of different pain-susceptible-neurons were analyzed to construct the pain modulatory network, which was corresponding to painful stimulus of changed intensity. Twelve volunteers underwent functional scanning receiving different electrical stimulation. The data were collected and analyzed to generate the corresponding functional activation maps and response time curves related to pain. The common activations were mainly located in several specific regions, including the secondary somatosensory cortex (SII), insula, anterior cingulate cortex (ACC), thalamus, and other cerebral regions. Moreover, innocuous electrical stimulation primarily activated the lateral portions of SII and thalamus, as well as the posterior insula, anterior ACC, whereas noxious electrical stimulation primarily activated the medial portions of SII and thalamus, as well as the anterior insula, the posterior ACC, with larger extensions and greater intensities. Several specified cerebral regions displayed different response patterns during electrical stimulation by means of fMRI, which implied that the corresponding pain-susceptible-neurons might process specific aspects of pain. Elucidation of functions on pain-related regions will help to understand the delicate pain modulation of human brain.

Reduced laser-evoked potential habituation detects abnormal central pain processing in painful radiculopathy patients.

PubMed

Hüllemann, P; von der Brelie, C; Manthey, G; Düsterhöft, J; Helmers, A K; Synowitz, M; Baron, R

2017-05-01

Repetitive painful laser stimuli lead to physiological laser-evoked potential (LEP) habituation, measurable by a decrement of the N2/P2 amplitude. The time course of LEP-habituation is reduced in the capsaicin model for peripheral and central sensitization and in patients with migraine and fibromyalgia. In the present investigation, we aimed to assess the time course of LEP-habituation in a neuropathic pain syndrome, i.e. painful radiculopathy. At the side of radiating pain, four blocks of 25 painful laser stimuli each were applied to the ventral thigh at the L3 dermatome in 27 patients with painful radiculopathy. Inclusion criteria were (1) at least one neurological finding of radiculopathy, (2) low back pain with radiation into the foot and (3) a positive one-sided compression of the L5 and/or S1 root in the MRI. The time course of LEP-habituation was compared to 20 healthy height and age matched controls. Signs of peripheral (heat hyperalgesia) and central sensitization (dynamic mechanical allodynia and hyperalgesia) at the affected L5 or S1 dermatome were assessed with quantitative sensory testing. Painful radiculopathy patients showed decreased LEP-habituation compared to controls. Patients with signs of central sensitization showed a more prominent LEP-habituation decrease within the radiculopathy patient group. Laser-evoked potential habituation is reduced in painful radiculopathy patients, which indicates an abnormal central pain processing. Central sensitization seems to be a major contributor to abnormal LEP habituation. The LEP habituation paradigm might be useful as a clinical tool to assess central pain processing alterations in nociceptive and neuropathic pain conditions. Abnormal central pain processing in neuropathic pain conditions may be revealed with the laser-evoked potential habituation paradigm. In painful radiculopathy patients, LEP-habituation is reduced compared to healthy controls. © 2017 European Pain Federation - EFIC®.

Effects of transcranial random noise stimulation (tRNS) on affect, pain and attention in multiple sclerosis.

PubMed

Palm, Ulrich; Chalah, Moussa A; Padberg, Frank; Al-Ani, Tarik; Abdellaoui, Mohamed; Sorel, Marc; Dimitri, Dalia; Créange, Alain; Lefaucheur, Jean-Pascal; Ayache, Samar S

2016-01-01

Pain and cognitive impairment are frequent symptoms in patients with multiple sclerosis (MS). Neglecting experimental pain and paying attention to demanding tasks is reported to decrease the pain intensity. Little is known about the interaction between chronic neuropathic pain and attention disorders in MS. Recently, transcranial direct current stimulation (tDCS) was used to modulate various cognitive and motor symptoms in MS. We aimed to study the effects of transcranial random noise stimulation (tRNS), a form of transcranial electric stimulation, over the left dorsolateral prefrontal cortex (DLPFC) on attention and neuropathic pain in MS patients. 16 MS patients were included in a randomized, sham-controlled, cross-over study. Each patient randomly received two tRNS blocks, separated by three weeks of washout interval. Each block consisted of three consecutive daily sessions of either active or sham tRNS. The patients were evaluated for pain, attention and mood and further underwent an electrophysiological evaluation. Compared to sham, tRNS showed a trend to decrease the N2-P2 amplitudes of pain related evoked potentials and improve pain ratings. Attention performance and mood scales did not change after stimulations. This study suggests the role of tRNS in pain modulation, which could have been more evident with longer stimulation protocols.

Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects

PubMed Central

Gomes, Adriana de Oliveira; Silvestre, Ana Caroline; da Silva, Cristina Ferreira; Gomes, Mariany Ribeiro; Bonfleur, Maria Lúcia; Bertolini, Gladson Ricardo Flor

2014-01-01

Objective To investigate the effects of different transcutaneous electrical nerve stimulation frequencies in nociception front of a pressure pain threshold and cold in healthy individuals. Methods Twenty healthy subjects were divided into four groups, all of which have gone through all forms of electrical stimulation at different weeks. Assessments were pre and post-therapy, 20 and 60 minutes after stimulation. To evaluate the pressure pain threshold, an algometer was used with one tapered tip, pressing the hypothenar region until voluntary report the word “pain”. Cold pain intensity was assessed by immersion in water at 5°C for 30 seconds; at the end, the subject was asked to quantify the pain intensity on a Visual Analog Scale for Pain. For electrical stimulation, two electrodes were used near the elbow, for 20 minutes, with an intensity strong, but not painful. The frequency was in accordance with the group: 0Hz (placebo); 7Hz; 100Hz; and 255Hz. Results Both for the assessment of pressure pain threshold as the cold pain intensity, there was no significant difference (p>0.05). Conclusion We conclude that the use of transcutaneous electrical nerve stimulation on dermatomes C6 to C8 produced no significant change in pressure pain threshold or cold discomfort. PMID:25295453

Differential inhibitory effect on human nociceptive skin senses induced by local stimulation of thin cutaneous fibers.

PubMed

Nilsson, H J; Schouenborg, J

1999-03-01

It is known that stimulation of thin cutaneous nerve fibers can induce long lasting analgesia through both supraspinal and segmental mechanisms, the latter often exhibiting restricted receptive fields. On this basis, we recently developed a new method, termed cutaneous field stimulation (CFS), for localized stimulation of A delta and C fibers in the superficial part of the skin. In the present study, we have evaluated the effects of CFS on non-nociceptive and nociceptive skin senses. We compared the effects of CFS with those of conventional transcutaneous electrical nerve stimulation (TENS), known to preferentially activate coarse myelinated fibers. A battery of sensory tests were made on the right volar forearm of 20 healthy subjects. CFS (16 electrodes, 4 Hz per electrode, 1 ms, up to 0.8 mA) and TENS (100 Hz, 0.2 ms, up to 26 mA) applied either on the right volar forearm (homotopically), or on the lower right leg (heterotopically) were used as conditioning stimulation for 25 min. The tactile threshold was not affected by either homo- or heterotopical CFS or TENS. The mean thresholds for detecting warming or cooling of the skin were increased by 0.4-0.9 degrees C after homo- but not heterotopical CFS and TENS. Regarding nociceptive skin senses, homo- but not heterotopical CFS, markedly reduced CO2-laser evoked A delta- and C fiber mediated heat pain to 75 and 48% of control, respectively, and mechanically evoked pain to 73% of control. Fabric evoked prickle, was not affected by CFS. Neither homo- nor heterotopical TENS induced any marked analgesic effects. It is concluded that different qualities of nociception can be differentially controlled by CFS.

Effect of Fiberoptic Collimation Technique on 808 nm Wavelength Laser Stimulation of Cochlear Neurons.

PubMed

Wang, Jingxuan; Lu, Jianren; Tian, Lan

2016-06-01

The purpose of this study was to evaluate the effects of fiberoptic collimation technique on auditory neural stimulation in the cochlea with 808 nm wavelength lasers. Recently, the pulsed near-infrared lasers in the 800-1000 nm wavelength range have been investigated as an emerging technique to trigger auditory neural response in the cochlea. A laser beam divergence in the optical stimulation pathway exists, which may affect stimulation efficiency and spatial selectivity. The fiberoptic collimation technique was proposed for cochlear neuron stimulation, and the C-lens element was designed as the collimation structure. The spiral ganglion cells in deafened guinea pigs' cochlea were irradiated with collimated and uncollimated near-infrared lasers. Optically evoked auditory brainstem response (OABR) under the two laser output modes were recorded. Laser with the collimation technique evoked an average 58% higher OABR amplitude than the uncollimated laser output. In addition, the collimated laser setup consumed on average 35.2% of laser energy compared with the uncollimated laser when evoking the same OABR amplitude. The fiberoptic collimation technique improved stimulation efficiency and reduced stimulating energy consumption in near-infrared neural stimulation in cochlea. The positive effects of laser collimation technique could benefit further research in optically based cochlear implants.

Effects of cardiopulmonary baroreceptor activation on pain may be moderated by risk for hypertension.

PubMed

Ditto, Blaine; Lewkowski, Maxim D; Rainville, Pierre; Duncan, Gary H

2009-10-01

Cardiopulmonary baroreceptor stimulation may modulate pain, though the literature is much smaller than research showing that sinoaortic baroreceptor stimulation can buffer pain. To examine the possibility that risk for established high blood pressure may moderate the effects of cardiopulmonary baroreceptor stimulation on pain, 22 borderline hypertensive and 18 normotensive men participated in a laboratory experiment. Group differences in blood pressure were documented by 24-h ambulatory blood pressure recording. Ratings of the intensity of acute heat pain were influenced by both group membership and leg position. Passive elevation of the legs, a technique that stimulates cardiopulmonary baroreceptors, reduced ratings of heat pain though only among borderline hypertensives. Alteration of pain sensitivity may reflect the development of the hypertensive process.

Selective Radiofrequency Stimulation of the Dorsal Root Ganglion (DRG) as a Method for Predicting Targets for Neuromodulation in Patients With Post Amputation Pain: A Case Series.

PubMed

Hunter, Corey W; Yang, Ajax; Davis, Tim

2017-10-01

While spinal cord stimulation (SCS) has established itself as an accepted and validated treatment for neuropathic pain, there are a number of conditions where it has experienced less, long-term success: post amputee pain (PAP) being one of them. Dorsal root ganglion (DRG) stimulation has shown great promise, particularly in conditions where traditional SCS has fallen short. One major difference between DRG stimulation and traditional SCS is the ability to provide focal stimulation over targeted areas. While this may be a contributing factor to its superiority, it can also be a limitation insofar stimulating the wrong DRG(s) can lead to failure. This is particularly relevant in conditions like PAP where neuroplastic maladaptation occurs causing the pain to deviate from expected patterns, thus creating uncertainty and variability in predicting targets for stimulation. We propose selective radiofrequency (RF) stimulation of the DRG as a method for preoperatively predicting targets for neuromodulation in patients with PAP. We present four patients with PAP of the lower extremities. RF stimulation was used to selectively stimulate individual DRG's, creating areas of paresthesias to see which most closely correlated/overlapped with the painful area(s). RF stimulation to the DRG's that resulted in the desirable paresthesia coverage in the residual or the missing limb(s) was recorded as "positive." Trial DRG leads were placed based on the positive RF stimulation findings. In each patient, stimulating one or more DRG(s) produced paresthesias patterns that were contradictory to know dermatomal patterns. Upon completion of a one-week trial all four patients reported 60-90% pain relief, with coverage over the painful areas, and opted for permanent implant. Mapping the DRG via RF stimulation appears to provide improved accuracy for determining lead placement in the setting of PAP where pain patterns are known to deviate from conventional dermatomal mapping. © 2017 International Neuromodulation Society.

Different activation of opercular and posterior cingulate cortex (PCC) in patients with complex regional pain syndrome (CRPS I) compared with healthy controls during perception of electrically induced pain: a functional MRI study.

PubMed

Freund, Wolfgang; Wunderlich, Arthur P; Stuber, Gregor; Mayer, Florian; Steffen, Peter; Mentzel, Martin; Weber, Frank; Schmitz, Bernd

2010-05-01

Although the etiology of complex regional pain syndrome type 1 (CRPS 1) is still debated, many arguments favor central maladaptive changes in pain processing as an important causative factor. To look for the suspected alterations, 10 patients with CRPS affecting the left hand were explored with functional magnetic resonance imaging during graded electrical painful stimulation of both hands subsequently and compared with healthy participants. Activation of the anterior insula, posterior cingulate cortex (PCC), and caudate nucleus was seen in patients during painful stimulation. Compared with controls, CRPS patients had stronger activation of the PCC during painful stimulation of the symptomatic hand. The comparison of insular/opercular activation between controls and patients with CRPS I during painful stimulation showed stronger (posterior) opercular activation in controls than in patients. Stronger PCC activation during painful stimulation may be interpreted as a correlate of motor inhibition during painful stimuli different from controls. Also, the decreased opercular activation in CRPS patients shows less sensory-discriminative processing of painful stimuli.These results show that changed cerebral pain processing in CRPS patients is less sensory-discriminative but more motor inhibition during painful stimuli. These changes are not limited to the diseased side but show generalized alterations of cerebral pain processing in chronic pain patients.

Electrical stimulation in the treatment of pain.

PubMed

Rushton, David N

2002-05-20

To review the published literature concerning the treatment of painful conditions using devices that deliver electrical stimulation to nervous structures. The review briefly surveys the results obtained using surface electrodes ("TENS") as well as implanted devices. The method used is a critical review of the important published literature up to mid-1999. References were obtained using Medline and the keywords "pain", together with "electrical", "stimulation", "neurostimulation" or "TENS". Electrical stimulation has been found to be of potential benefit in the management of a range of painful conditions. Adequately controlled trials of electrical stimulation are often difficult to achieve. Implanted devices tend to be used in the more severe intractable pain conditions. It is likely that there is more than one mechanism of action. The mechanisms of action are however still often poorly understood, even though historically theoretical and experimental advances in the understanding of pain mechanisms prompted the development of clinical systems and the institution of clinical studies. TENS has proved to be remarkably safe, and provides significant analgesia in about half of patients experiencing moderate predictable pain. Implanted devices can be more effective, but they carry a risk of device failure, implant infection or surgical complication, and are reserved for the more severe intractable chronic pains. The main implanted devices used clinically are the spinal cord stimulator and the deep brain stimulator.

Analgesic efficacy of cerebral and peripheral electrical stimulation in chronic nonspecific low back pain: a randomized, double-blind, factorial clinical trial.

PubMed

Hazime, Fuad Ahmad; de Freitas, Diego Galace; Monteiro, Renan Lima; Maretto, Rafaela Lasso; Carvalho, Nilza Aparecida de Almeida; Hasue, Renata Hydee; João, Silvia Maria Amado

2015-01-31

Chronic non-specific low back pain is a major socioeconomic public health issue worldwide and, despite the volume of research in the area, it is still a difficult-to-treat condition. The conservative analgesic therapy usually comprises a variety of pharmacological and non-pharmacological strategies, such as transcutaneous electrical nerve stimulation. The neuromatrix pain model and the new findings on the process of chronicity of pain point to a higher effectiveness of treatments that address central rather than peripheral structures. The transcranial direct current stimulation is a noninvasive technique of neuromodulation that has made recent advances in the treatment of chronic pain. The simultaneous combination of these two electrostimulation techniques (cerebral and peripheral) can provide an analgesic effect superior to isolated interventions. However, all the evidence on the analgesic efficacy of these techniques, alone or combined, is still fragmented. This is a protocol for a randomized clinical trial to investigate whether cerebral electrical stimulation combined with peripheral electrical stimulation is more effective in relieving pain than the isolated application of electrical stimulations in patients with chronic nonspecific low back pain. Ninety-two patients will be randomized into four groups to receive transcranial direct current stimulation (real/sham) + transcutaneous electrical nerve stimulation (real/sham) for 12 sessions over a period of four weeks. The primary clinical outcome (pain intensity) and the secondary ones (sensory and affective aspects of pain, physical functioning and global perceived effect) will be recorded before treatment, after four weeks, in Month 3 and in Month 6 after randomization. Confounding factors such as anxiety and depression, the patient's satisfaction with treatment and adverse effects will also be listed. Data will be collected by an examiner unaware of (blind to) the treatment allocation. The results of this study may assist in clinical decision-making about the combined use of cerebral and peripheral electrical stimulation for pain relief in patients with chronic low back pain. NCT01896453.

The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

PubMed

Park, C; Choi, J B; Lee, Y-S; Chang, H-S; Shin, C S; Kim, S; Han, D W

2015-04-01

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

PubMed

Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

2016-01-01

Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008). Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias.

The synergistic effect on osteogenic differentiation of human mesenchymal stem cells by diode laser-treated stimulating human umbilical vein endothelial cells

NASA Astrophysics Data System (ADS)

Kao, Chia-Tze; Hsu, Tuan-Ti; Huang, Tsui-Hsien; Wu, Yu-Tin; Chen, Yi-Wen; Shie, Ming-You

2016-02-01

Angiogenesis plays an important role in determining the biostimulation of bone regeneration, in either new bone or blood vessel formation. Human umbilical cord cells (HUVECs) are important effector cells in angiogenesis and are indispensable for osteogenesis and for their heterogeneity and plasticity. However, there are very few studies about the effects of HUVECs on diode laser-stimulated/regulated osteogenesis. In this study, we used diode laser as a model biostimulation to examine the role of HUVECs on laser-stimulated osteogenesis. Several bone formation-related proteins were also significantly up-regulated by the diode laser stimulation, indicating that HUVECs may participate in diode laser-stimulated osteogenesis. Interestingly, when human mesenchymal stem cells (hMSCs) cultured with HUVECs were diode laser-treated, the osteogenesis differentiation of the hMSCs was significantly promoted, indicating the important role of HUVECs in diode laser-enhanced osteogenesis. Adequately activated HUVECs are vital for the success of diode laser-stimulated hard-tissue regeneration. These findings provided valuable insights into the mechanism of diode laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment in periodontal repair.

Some Words Hurt More Than Others: Semantic Activation of Pain Concepts in Memory and Subsequent Experiences of Pain.

PubMed

Swannell, Ellen R; Brown, Christopher A; Jones, Anthony K P; Brown, Richard J

2016-03-01

Theory suggests that as activation of pain concepts in memory increases, so too does subsequent pain perception. Previously, researchers have found that activating pain concepts in memory increases pain perception of subsequent painful stimuli, relative to neutral information. However, they have not attempted to quantify the nature of the association between information studied and ensuing pain perception. We subliminally presented words that had either a low or high degree of association to the word 'pain,' although this was only partially successful and some words were consciously perceived. Participants then received randomized laser heat stimuli, delivered at 1 of 3 intensity levels (low, moderate, high), and we measured the effect of this on behavioral and electrophysiological measures of pain. Participants (N = 27) rated moderate- and high-intensity laser stimuli as more painful after viewing high relative to low associates of pain; these effects remained present when we controlled for measures of mood, anxiety, and physical symptom reporting. Similar effects were observed physiologically, with higher stimulus negativity preceding after high relative to low associates and greater amplitudes for the N2 component of the laser-evoked potential after presentation of high associates in the moderate and high laser intensity conditions. These data support activation-based models of the effects of memory on pain perception. Consistent with current theories of memory and pain, we found that high, relative to low activation of pain concepts in memory increased psychological and physiological responses to laser-induced pain. The effect remained regardless of whether participants showed conscious awareness of activation. Theoretical and clinical implications are discussed. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Treatment of Pain and Autonomic Dysreflexia in Spinal Cord Injury with Deep Brain Stimulation

DTIC Science & Technology

2015-10-01

currently investigating the effects of CG stimulation in subjects with debilitating pain due to cervical or thoracic SCI. This study stemmed from...had a low thoracic injury and pain in lumbar dermatomes, whereas Subject 1 had mainly mid- cervical pain that responded minimally to DBS and matched...AWARD NUMBER: W81XWH-12-1-0559 TITLE: Treatment of Pain and Autonomic Dysreflexia in Spinal Cord Injury with Deep Brain Stimulation PRINCIPAL

Evaluation of pain on use of electrosurgery and diode lasers in the management of gingival hyperpigmentation: A comparative study

PubMed Central

Chandna, Shalu; Kedige, Suresh Dyamappa

2015-01-01

Background: Gingival depigmentation is a periodontal plastic surgical procedure whereby the gingival hyperpigmentation is removed by various techniques such as electrosurgery, cryosurgery, abrasion with diamond bur and lasers. The aim of this study was to determine the pain levels during the gingival depigmentation procedure using electrosurgery and lasers. Materials and Methods: Twenty patients, both male and female, between the ages of 20 and 40 years were randomly allocated into two groups of 10 patients each: Those undergoing depigmentation with electrosurgery (Group I) and those by diode lasers (Group II). Patients of both groups were asked to define the level of pain and discomfort by using the Visual Analog Scale (VAS) intraoperatively, 24 h post-operatively and 1 week post-operatively. Results: Both the groups showed a decrease in the pain levels, which was statistically highly significant 1 week post-operatively when compared 24 h post-operatively. There was a statistically highly significant difference in the pain levels between the electrosurgery and the lasers groups after 24 h (P < 0.001), with the lasers group demonstrating lesser pain and discomfort. Although there was no significant difference between the two groups intraoperatively and 1 week post-operatively on comparison, lesser mean scores were observed for the lasers group. Conclusion: The growing concern for esthetic requires the removal of hyperpigmentated gingival areas to create a confident and pleasant smile, which could be easily attained by using either electrosurgery or lasers. This study concluded that lasers produce lesser pain and discomfort compared with electrosurgery during gingival depigmentation. PMID:25810593

Spinal cord stimulation for the treatment of chronic back pain patients: 500-Hz vs. 1000-Hz burst stimulation.

PubMed

Van Havenbergh, Tony; Vancamp, Tim; Van Looy, Pieter; Vanneste, Sven; De Ridder, Dirk

2015-01-01

Spinal cord stimulation is a commonly used, safe, and effective procedure applied for medically intractable failed back surgery syndrome, as well as other neuropathic pain syndromes. Recently, a novel stimulation paradigm called burst stimulation has been developed that is paresthesia-free and has a more pronounced suppressive effect on neuropathic pain. Fifteen patients who were being treated with burst spinal cord stimulation for failed back surgery syndrome participated in an open-label trial to verify whether their pain suppression could be further ameliorated by changing the burst pattern. Burst stimulation with packets of five electrical pulses delivered at 500 Hz with 1000-μsec pulse width 40 times per second was changed to burst mode delivering five spikes at 1000 Hz with 500-μsec pulse width 40 times a second. As the amplitudes did not differ between the two groups, the total delivery of current to the spinal cord was not different between the two modes of burst stimulation. Scores on visual analog scales for pain and paresthesia, the Pain Catastrophizing Scale, the Pain Vigilance and Awareness Questionnaire, and the Short Form 36 quality of life measurement were compared between the two modes of burst stimulation. [Correction added on 06 Feb 2015, after first online publication: this paragraph has been revised to signify the comparison of amplitudes between two groups] No statistically significant differences were found between the two modes of stimulation. The results suggest that increasing the frequency from 500 to 1000 Hz while keeping the pulse width constant does not add any extra benefit in suppressing pain. Further studies should verify whether increasing the frequency above 1000 Hz has a similar lack of effect. © 2014 International Neuromodulation Society.

Nociception and inflammatory hyperalgesia evaluated in rodents using infrared laser stimulation after Trpv1 gene knockout or resiniferatoxin lesion.

PubMed

Mitchell, Kendall; Lebovitz, Evan E; Keller, Jason M; Mannes, Andrew J; Nemenov, Michael I; Iadarola, Michael J

2014-04-01

TRPV1 is expressed in a subpopulation of myelinated Aδ and unmyelinated C-fibers. TRPV1+ fibers are essential for the transmission of nociceptive thermal stimuli and for the establishment and maintenance of inflammatory hyperalgesia. We have previously shown that high-power, short-duration pulses from an infrared diode laser are capable of predominantly activating cutaneous TRPV1+ Aδ-fibers. Here we show that stimulating either subtype of TRPV1+ fiber in the paw during carrageenan-induced inflammation or following hind-paw incision elicits pronounced hyperalgesic responses, including prolonged paw guarding. The ultrapotent TRPV1 agonist resiniferatoxin (RTX) dose-dependently deactivates TRPV1+ fibers and blocks thermal nociceptive responses in baseline or inflamed conditions. Injecting sufficient doses of RTX peripherally renders animals unresponsive to laser stimulation even at the point of acute thermal skin damage. In contrast, Trpv1-/- mice, which are generally unresponsive to noxious thermal stimuli at lower power settings, exhibit withdrawal responses and inflammation-induced sensitization using high-power, short duration Aδ stimuli. In rats, systemic morphine suppresses paw withdrawal, inflammatory guarding, and hyperalgesia in a dose-dependent fashion using the same Aδ stimuli. The qualitative intensity of Aδ responses, the leftward shift of the stimulus-response curve, the increased guarding behaviors during carrageenan inflammation or after incision, and the reduction of Aδ responses with morphine suggest multiple roles for TRPV1+ Aδ fibers in nociceptive processes and their modulation of pathological pain conditions. Copyright © 2014. Published by Elsevier B.V.

[Beta-1 adrenoceptor blockade decreases the firing rate to painful stimuli in spinal wide-dynamic range neurons in rats].

PubMed

Lamothe-Molina, Paul J; Lamothe-Molina, Pedro A; López-Ávila, Alberto

2014-01-01

It is known that epinephrine/norepinephrine inhibit acute pain transmission. However, the role of ß-adrenoceptors is not clear. Thus, we analyzed if beta-1 and/or beta-2 adrenoceptors can modulate acute pain transmission by performing in vivo single unit recordings during painful and non-painful peripheral stimulation in rats. Longitudinal study in which we analyzed seven groups of male rats Wistar: control group (n = 11): saline (0.9 %); EPI group (n = 8): epinephrine 100 mcg; beta-1 agonist group (n = 8): dobutamine 125 mcg; beta-1-antagonist group (n = 9): metoprolol 100 mcg; beta-2-agonist group (n = 7): clenbuterol 100 mcg; beta-2-antagonist group (n = 8): butoxamine 100 mcg; beta-1-antagonist + EPI group (n = 10): metoprolol 100 mcg + epinephrine 100 mcg. For the statistical analysis we used ANOVA. Epinephrine significantly reduced the basal firing rate (BFR) in 34.1 % (p < 0.05) and also the evoked response by painful stimulation in 56 % (p < 0.05). No change was observed in the evoked response by non-painful stimulation. ANTß1 was the only beta-adrenoceptor acting drug that significantly reduced the evoked response by painful stimulation in 41 % (p < 0.05). None of the other drugs alone affected either the BFR or the evoked response to non-painful or painful stimulation. It is the first time that a beta-1-adrenoceptor antagonist (metoprolol) probes to be effective in reducing the response to painful stimulation in WDR neurons.

Numbness in clinical and experimental pain--a cross-sectional study exploring the mechanisms of reduced tactile function.

PubMed

Geber, Christian; Magerl, Walter; Fondel, Ricarda; Fechir, Marcel; Rolke, Roman; Vogt, Thomas; Treede, Rolf-Detlef; Birklein, Frank

2008-09-30

Pain patients often report distinct numbness of the painful skin although no structural peripheral or central nerve lesion is obvious. In this cross-sectional study we assessed the reduction of tactile function and studied underlying mechanisms in patients with chronic pain and in healthy participants exposed to phasic and tonic experimental nociceptive stimulation. Mechanical detection (MDT) and pain thresholds (MPT) were assessed in the painful area and the non-painful contralateral side in 10 patients with unilateral musculoskeletal pain. Additionally, 10 healthy participants were exposed to nociceptive stimulation applied to the volar forearms (capsaicin; electrical stimulation, twice each). Areas of tactile hypaesthesia and mechanical hyperalgesia were assessed. MDT and MPT were quantified adjacent to the stimulation site. Tactile hypaesthesia in pain patients and in experimental pain (MDT-z-scores: -0.66+/-0.30 and -0.42+/-0.15, respectively, both p<0.01) was paralleled by mechanical hyperalgesia (MPT-z-scores: +0.51+/-0.27, p<0.05; and +0.48+/-0.10, p<0.001). However, hypaesthesia and hyperalgesia were not correlated. Although 9 patients reported numbness, only 3 of them were able to delineate circumscript areas of tactile hypaesthesia. In experimental pain, the area of tactile hypaesthesia could be mapped in 31/40 experiments (78%). Irrespective of the mode of nociceptive stimulation (phasic vs. tonic) tactile hypaesthesia and hyperalgesia developed with a similar time course and disappeared within approximately 1 day. Hypaesthesia (numbness) often encountered in clinical pain can be reproduced by experimental nociceptive stimulation. The time course of effects suggests a mechanism involving central plasticity.

Ultrasound-guided, percutaneous peripheral nerve stimulation: technical note.

PubMed

Chan, Isaac; Brown, Anthony R; Park, Kenneth; Winfree, Christopher J

2010-09-01

Peripheral nerve stimulation is a form of neuromodulation that applies electric current to peripheral nerves to induce stimulation paresthesias within the painful areas. To report a method of ultrasound-guided, percutaneous peripheral nerve stimulation. This technique utilizes real-time imaging to avoid injury to adjacent vascular structures during minimally invasive placement of peripheral nerve stimulator electrodes. We describe a patient that presented with chronic, bilateral foot pain following multiple foot surgeries, for whom a comprehensive, pain management treatment strategy had failed. We utilized ultrasound-guided, percutaneous tibial nerve stimulation at a thigh level to provide durable pain relief on the right side, and open peripheral nerve stimulation on the left. The patient experienced appropriate stimulation paresthesias and excellent pain relief on the plantar aspect of the right foot with the percutaneous electrode. On the left side, we were unable to direct the stimulation paresthesias to the sole of the foot, despite multiple electrode repositionings. A subsequent, open placement of a left tibial nerve stimulator was performed. This revealed that the correct electrode position against the tibial nerve was immediately adjacent to the popliteal artery, and was thus not appropriate for percutaneous placement. We describe a method of ultrasound-guided peripheral nerve stimulation that avoids the invasiveness of electrode placement via an open procedure while providing excellent pain relief. We further describe limitations of the percutaneous approach when navigating close to large blood vessels, a situation more appropriately managed with open peripheral nerve stimulator placement. Ultrasound-guided placement may be considered for patients receiving peripheral nerve stimulators placed within the deep tissues, and not easily placed in a blind fashion.

Multimodal pain stimulation of the gastrointestinal tract

PubMed Central

Drewes, Asbjørn Mohr; Gregersen, Hans

2006-01-01

Understanding and characterization of pain and other sensory symptoms are among the most important issues in the diagnosis and assessment of patient with gastrointestinal disorders. Methods to evoke and assess experimental pain have recently developed into a new area with the possibility for multimodal stimulation (e.g., electrical, mechanical, thermal and chemical stimulation) of different nerves and pain pathways in the human gut. Such methods mimic to a high degree the pain experienced in the clinic. Multimodal pain methods have increased our basic understanding of different peripheral receptors in the gut in health and disease. Together with advanced muscle analysis, the methods have increased our understanding of receptors sensitive to mechanical, chemical and temperature stimuli in diseases, such as systemic sclerosis and diabetes. The methods can also be used to unravel central pain mechanisms, such as those involved in allodynia, hyperalgesia and referred pain. Abnormalities in central pain mechanisms are often seen in patients with chronic gut pain and hence methods relying on multimodal pain stimulation may help to understand the symptoms in these patients. Sex differences have been observed in several diseases of the gut, and differences in central pain processing between males and females have been hypothesized using multimodal pain stimulations. Finally, multimodal methods have recently been used to gain more insight into the effect of drugs against pain in the GI tract. Hence, the multimodal methods undoubtedly represents a major step forward in the future characterization and treatment of patients with various diseases of the gut. PMID:16688791

Effectiveness of low-level laser therapy on pain intensity, pressure pain threshold, and SF-MPQ indexes of women with myofascial pain.

PubMed

Magri, Laís Valencise; Carvalho, Vinícius Almeida; Rodrigues, Flávia Cássia Cabral; Bataglion, César; Leite-Panissi, Christie Ramos Andrade

2017-02-01

Women with temporomandibular disorders (TMD) frequently report pain areas in body regions. This process is associated with central sensitization phenomena, present in chronic pain. The low-level laser therapy (LLLT) has been reported as a therapeutic option for the painful TMD treatment. The aim of this study was to analyze the effect of LLLT on pain intensity (visual analogue scale, VAS), pain sensitivity in orofacial and corporal points (pressure pain threshold, PPT), and on Short Form-McGill Pain Questionnaire (SF-MPQ) indexes of women with myofascial pain (subtype of muscle TMD). Ninety-one women (18-60 years) were included in the study, among which 61 were diagnosed with myofascial pain (Research Diagnostic Criteria for Temporomandibular Disorder-Ia and Ib) and were divided into laser (n = 31) and placebo group (n = 30), and 30 were controls. The LLLT was applied at pre-established points, twice a week, eight sessions (780 nm; masseter and anterior temporal = 5 J/cm 2 , 20 mW, 10 s; TMJ area = 7.5 J/cm 2 , 30 mW, 10 s). Pain intensity, pain sensitivity, and the SF-MPQ indexes were measured at the baseline, during laser sessions, and 30 days after treatment. For intra-group comparisons, the Friedman test was performed, and for inter-group, the Mann-Whitney test. Increased pain sensitivity was found in women with myofascial pain when compared to controls (p < 0.05). There was a reduction in pain intensity for both groups after LLLT. The LLLT did not change the PPT for any group (p > 0.05). Active laser and placebo reduced the indexes of sensory, total pain, and VAS, maintaining the results after 30 days; there was a reduction in the affective pain rating index for both groups, with no maintenance after 30 days for placebo, and the present pain intensity decreased in the laser group and did not change in the placebo after LLLT. In conclusion, the LLLT active or placebo are effective in reducing the overall subjective perception of myofascial pain (VAS and SF-MPQ indexes); however, they have no effectiveness in reducing the pain sensitivity in orofacial and corporal points (PPT increase).

Comparison of pain and swelling after removal of oral leukoplakia with CO2 laser and cold knife: A randomized clinical trial

PubMed Central

López-Jornet, Pía

2013-01-01

Objective: The aim of this study was to compare conventional surgery with carbon dioxide (CO2) laser in patients with oral leukoplakia, and to evaluate the postoperative pain and swelling. Study design: A total of 48 patients (27 males and 21 females) with a mean age of 53.7 ± 11.7 years and diagnosed with oral leukoplakia were randomly assigned to receive treatment either with conventional surgery using a cold knife or with a CO2 laser technique. A visual analog scale (VAS) was used to score pain and swelling at different postoperative time points. Results: Pain and swelling reported by the patients was greater with the conventional cold knife than with the CO2 laser, statistically significant differences for pain and swelling were observed between the two techniques during the first three days after surgery. Followed by a gradual decrease over one week. In neither group was granuloma formation observed, and none of the patients showed malignant transformation during the period of follow-up. Conclusions: The CO2 laser causes only minimal pain and swelling, thus suggesting that it may be an alternative method to conventional surgery in treating patients with oral leukoplakia. Key words:Oral leukoplakia, treatment, laser surgery, cold knife, pain, swelling. PMID:23229239

Muscle relaxation for individuals having tattoos removed through laser treatment: possible effects regarding anxiety and pain.

PubMed

Huang, Faye; Chou, Wen-Jiun; Chen, Tien-Hsing; Chen, Ching; Hsieh, Yu-Lian; Chong, Mian-Yoon; Hung, Chi-Fa; Lin, Shu-Ching; Tsai, Hsiu-Huang; Wang, Liang-Jen

2016-08-01

Effectively managing pain is vital for the well-being and satisfaction of patients undergoing dermatologic treatments involving lasers. This study investigates the potential outcome of using muscle relaxation techniques to reduce pain among people having their tattoos removed with laser treatment. This study consists of 56 participants (mean age 18.1 ± 2.1 years) that had tattoos removed using the principle of selective photothermolysis. These participants underwent muscle relaxation before receiving the laser treatment. Their peripheral skin temperatures (PST) were measured both at the beginning and the end of the muscle relaxation period. Then, the Beck Anxiety Inventory was applied to evaluate anxiety levels. Once the laser treatment was completed, pain levels were measured using a visual analogue scale. A total of 125 person-sessions of laser treatment and psychometric assessments were performed in this study. The muscle relaxation method significantly increased the PST of the participants while reducing the levels of anxiety and pain throughout the course of the laser treatment procedure. The PST, anxiety scores, and pain scores all showed significant correlations with one another. According to the results obtained, this study proposes that muscle relaxation techniques be considered possibly auxiliary treatment options for individuals having tattoos removed through laser treatment. Additional studies with a comparison group and a larger sample size are required in the future to confirm the effectiveness of such intervention.

Pain score assessment in babies undergoing laser treatment for retinopathy of prematurity under sub-tenon anaesthesia.

PubMed

Novitskaya, E S; Kostakis, V; Broster, S C; Allen, L E

2013-12-01

To assess the tolerability and outcomes of laser treatment for retinopathy of prematurity (ROP) under sub-tenon anaesthetic with oral or rectal sedation using a reliable, multidimensional, and internationally accepted tool for assessment of neonatal pain. Sixty-two babies have had ROP laser treatment in our neonatal unit in the 7-year interval between 1 March 2005 and 28 February 2012; 44% (27 of the 62) were performed using sub-tenon anaesthesia. Pain scores were routinely assessed using the Neonatal Pain Agitation and Sedation Scale (N-PASS) every 10 min during laser treatment. The outcome and requirement for re-treatment in this group was compared with that in the intravenous sedation group. Pain scores were available in 19 of the 27 babies treated under sub-tenon anaesthesia. The mean pain score during treatment was 2.7 (SD ± 1.7, range 0.5-6.2). There was no statistically significant correlation between the mean pain score and duration of treatment (Spearman correlation coefficient (ρ) = 0.31; P = 0.09), number of laser burns (ρ = 0.32; P = 0.09), or post-menstrual age of the baby at the time of treatment (ρ = 0.38; P = 0.052). Treatments performed under sub-tenon anaesthesia were as successful as those performed under intravenous sedation. The mean pain scores during laser treatment under sub-tenon anaesthesia in our study were lower than those previously reported during ROP screening or heel-stick procedure.Conclusion Our study demonstrated that sub-tenon anaesthesia with oral or rectal sedation provides sufficient pain control for laser treatment for ROP without the need or risks of intravenous sedation and intubation.

High-Frequency Transcutaneous Peripheral Nerve Stimulation Induces a Higher Increase of Heat Pain Threshold in the Cutaneous Area of the Stimulated Nerve When Confronted to the Neighbouring Areas

PubMed Central

Buonocore, M.; Camuzzini, N.; Cecini, M.; Dalla Toffola, E.

2013-01-01

Background. TENS (transcutaneous electrical nerve stimulation) is probably the most diffused physical therapy used for antalgic purposes. Although it continues to be used by trial and error, correct targeting of paresthesias evoked by the electrical stimulation on the painful area is diffusely considered very important for pain relief. Aim. To investigate if TENS antalgic effect is higher in the cutaneous area of the stimulated nerve when confronted to neighbouring areas. Methods. 10 volunteers (4 males, 6 females) underwent three different sessions: in two, heat pain thresholds (HPTs) were measured on the dorsal hand skin before, during and after electrical stimulation (100 Hz, 0.1 msec) of superficial radial nerve; in the third session HPTs, were measured without any stimulation. Results. Radial nerve stimulation induced an increase of HPT significantly higher in its cutaneous territory when confronted to the neighbouring ulnar nerve territory, and antalgic effect persisted beyond the stimulation time. Conclusions. The location of TENS electrodes is crucial for obtaining the strongest pain relief, and peripheral nerve trunk stimulation is advised whenever possible. Moreover, the present study indicates that continuous stimulation could be unnecessary, suggesting a strategy for avoiding the well-known tolerance-like effect of prolonged TENS application. PMID:24027756

Effiectiveness and safety of transcranial direct current stimulation in fibromyalgia: A systematic review and meta-analysis.

PubMed

Zhu, Chang-E; Yu, Bo; Zhang, Wen; Chen, Wen-Hua; Qi, Qi; Miao, Yun

2017-01-19

To evaluate the effectiveness and safety of transcranial direct current stimulation for fibro-myalgia. Databases, conference records and registered trials were searched for articles published from the date of establishment of the database through to October 2015. Six randomized controlled trials (n=192) of transcranial direct current stimulation for fibromyalgia were included in the current study. Two researchers independently screened the literature, assessed methodological quality using the Cochrane Collaboration's tool, and extracted data. Studies were divided into 3 groups for meta-analysis according to stimulation site and polarity. Significant improvement in pain and general fibromyalgia-related function was seen with anodal transcranial direct current stimulation over the primary motor cortex (p<0.05). However, the pressure pain threshold did not improve (p>0.05). Anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex did not significantly reduce pain or improve general fibromyalgia-related function compared with sham stimulation (p>0.05). Cathodal transcranial direct current stimulation over the primary motor cortex did not improve the pressure pain threshold compared with sham stimulation (p>0.05). No significant adverse effects were seen. Anodal transcranial direct current stimulation over the primary motor cortex is more likely than sham transcranial direct current stimulation to relieve pain and improve general fibromyalgia-related function.

Standardizing procedures to study sensitization of human spinal nociceptive processes: comparing parameters for temporal summation of the nociceptive flexion reflex (TS-NFR).

PubMed

Terry, Ellen L; France, Christopher R; Bartley, Emily J; Delventura, Jennifer L; Kerr, Kara L; Vincent, Ashley L; Rhudy, Jamie L

2011-09-01

Temporal summation of pain (TS-pain) is the progressive increase in pain ratings during a series of noxious stimulations. TS-pain has been used to make inferences about sensitization of spinal nociceptive processes; however, pain report can be biased thereby leading to problems with this inference. Temporal summation of the nociceptive flexion reflex (TS-NFR, a physiological measure of spinal nociception) can potentially overcome report bias, but there have been few attempts (generally with small Ns) to standardize TS-NFR procedures. In this study, 50 healthy participants received 25 series of noxious electric stimulations to evoke TS-NFR and TS-pain. Goals were to: 1) determine the stimulation frequency that best elicits TS-NFR and reduces electromyogram (EMG) contamination from muscle tension, 2) determine the minimum number of stimulations per series before NFR summation asymptotes, 3) compare NFR definition intervals (90-150ms vs. 70-150ms post-stimulation), and 4) compare TS-pain and TS-NFR when different stimulation frequencies are used. Results indicated TS-NFR should be elicited by a series of three stimuli delivered at 2.0Hz and TS-NFR should be defined from a 70-150ms post-stimulation scoring interval. Unfortunately, EMG contamination from muscle tension was greatest during 2.0Hz series. Discrepancies were noted between TS-NFR and TS-pain which raise concerns about using pain ratings to infer changes in spinal nociceptive processes. And finally, some individuals did not have reliable NFRs when the stimulation intensity was set at NFR threshold during TS-NFR testing; therefore, a higher intensity is needed. Implications of findings are discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Step-down vs. step-up noxious stimulation: differential effects on pain perception and patterns of brain activation.

PubMed

Choi, J C; Kim, J; Kang, E; Choi, J-H; Park, W Y; Choi, Y-S; Cha, J; Han, C; Park, S K; Kim, M H; Lee, G H; Do, H-J; Jung, S W; Lee, J-M

2016-01-01

We hypothesize that pain and brain responses are affected by changes in the presentation sequence of noxious stimuli that are, overall, identical in intensity and duration. During functional magnetic resonance imaging (fMRI) scanning, 21 participants experienced three patterns of noxious stimulation: Up-type (step-up noxious stimulation, 15 s), Down-type (step-down noxious stimulation, 15 s), and Down-up-type (decreasing and increasing pattern of noxious stimulation, 15 s). The total intensity and duration of the three noxious stimulation patterns were identical, but the stimulation sequences were different. Pain and unpleasantness ratings in the Down- and Down-up-type noxious stimulations were lower than in the Up-type noxious stimulation. The left prefrontal cortex [(PFC, BA (Brodmann area) 10, (-45, 50, 1)] was more highly activated in the Down- and Down-up-type noxious stimulations than in the Up-type noxious stimulation. The S1, S2, insula, bilateral PFC (BA 46), and midcingulate cortex were more highly activated in the Up-type noxious stimulation than in the Down-type noxious stimulation. PFC BA 10 was located at an inferior level compared to the bilateral PFC BA 46 (Z axis = 1 for BA 10, compared to 22 and 25 for the right and left BA 46, respectively). When cortisol level was increased, the left hippocampal cortex, along with the left parahippocampal cortex, was greatly activated for the Up-type noxious stimulation. When pain cannot be avoided in clinical practice, noxious stimuli should be applied to patients in a step-down pattern that delivers the most intense pain first and the least intense pain last. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Laser stimulation can activate autophagy in HeLa cells

NASA Astrophysics Data System (ADS)

Wang, Yisen; Lan, Bei; He, Hao; Hu, Minglie; Cao, Youjia; Wang, Chingyue

2014-10-01

For decades, lasers have been a daily tool in most biological research for fluorescent excitation by confocal or multiphoton microscopy. More than 20 years ago, cell photodamage caused by intense laser stimulation was noticed by generating reactive oxygen species, which was then thought as the main damage effect by photons. In this study, we show that laser stimulation can induce autophagy, an important cell lysosomal pathway responding to immune stimulation and starvation, without any biochemical treatment. Two different types of laser stimulations are found to be capable of activating autophagy: continuous scanning by continuous-wave visible lasers and a short-time flash of femtosecond laser irradiation. The autophagy generation is independent from wavelength, power, and scanning duration of the visible lasers. In contrast, the power of femtosecond laser is very critical to autophagy because the multiphoton excited Ca2+ dominates autophagy signaling. In general, we show here the different mechanisms of autophagy generation by such laser stimulation, which correspond to confocal microscopy and cell surgery, respectively. Those results can help further understanding of photodamage and autophagy signaling.

Laser stimulation can activate autophagy in HeLa cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yisen; Hu, Minglie; Wang, Chingyue

For decades, lasers have been a daily tool in most biological research for fluorescent excitation by confocal or multiphoton microscopy. More than 20 years ago, cell photodamage caused by intense laser stimulation was noticed by generating reactive oxygen species, which was then thought as the main damage effect by photons. In this study, we show that laser stimulation can induce autophagy, an important cell lysosomal pathway responding to immune stimulation and starvation, without any biochemical treatment. Two different types of laser stimulations are found to be capable of activating autophagy: continuous scanning by continuous-wave visible lasers and a short-time flashmore » of femtosecond laser irradiation. The autophagy generation is independent from wavelength, power, and scanning duration of the visible lasers. In contrast, the power of femtosecond laser is very critical to autophagy because the multiphoton excited Ca{sup 2+} dominates autophagy signaling. In general, we show here the different mechanisms of autophagy generation by such laser stimulation, which correspond to confocal microscopy and cell surgery, respectively. Those results can help further understanding of photodamage and autophagy signaling.« less

Prospective study of the 532 nm laser (KTP) versus diode laser 980 nm in the resection of hyperplastic lesions of the oral cavity

PubMed Central

Bargiela-Pérez, Patricia; González-Merchán, Jorge; Díaz-Sánchez, Rosa; Serrera-Figallo, Maria-Angeles; Volland, Gerd; Joergens, Martin; Gutiérrez-Pérez, Jose-Luis

2018-01-01

Background The aim of this study is to evaluate the resection of hyperplastic lesions on the buccal mucosa comparing the 532nm laser (KTP), versus diode 980nm laser, considering pain, scarring, inflammation and drug consumption that occurred postoperatively with each lasers. Material and Methods A prospective study of consecutive series of 20 patients in two groups that presents hyperplastic lesions on the buccal mucosa. The choice of the KTP laser or diode 980nm laser for the surgery was made randomly. The power used was 1.5W in both groups in a continuous wave mode with a 320 μm optical fiber. Parameters of pain, scarring, inflammation and consumption of drugs were recorded by a Numerical Rating Scale and evaluated postoperatively. These recordings were made the day of the surgery, 24 hours after, 14 and 28 days after. Results Pain and inflammation was light - moderate. The consumption of paracetamol was somewhat higher in the diode 980nm laser versus the KTP laser after 24 hours, although data was not statistically significant; significant differences were found after 28 days in regards to pain (p = 0.023) and inflammation (p = 0.023), but always in the absence parameter so we find no pain in both lasers. Scarring in the two types of laser showed no differences along the visits, with not detected scar retractable. Conclusions Although there is a slight histological difference regarding the KTP laser in the oral soft tissues for clinical use, both wavelengths are very suitable for excision of oral fibroma. Key words:Laser surgery, Laser therapy, oral surgery, soft tissue, 980 nm diode laser, 532 nm KTP laser. PMID:29274158

The effects of two different low level laser therapies in the treatment of patients with chronic low back pain: A double-blinded randomized clinical trial.

PubMed

Koldaş Doğan, Şebnem; Ay, Saime; Evcik, Deniz

2017-01-01

The purpose of this study was to compare the effectiveness of two different laser therapy regimens on pain, lumbar range of motions (ROM) and functional capacity in patients with chronic low back pain (CLBP). Forty nine patients with CLBP were randomly assigned into two groups. Group 1 (n= 20) received hot-pack + laser therapy 1 (wavelength of 850 nm Gallium-Aluminum-Arsenide (Ga-Al-As) laser); group 2 (n= 29) received hot-pack + laser therapy 2 (wavelength of 650 nm Helyum-Neon (He-Ne), 785 ve 980 nm Gal-Al-As combined plaque laser) for 15 sessions. Pain severity, patient's and physician's global assessments were evaluated with visual analogue scale (VAS). Modified Schober test, right and left lateral flexion measurements were done. Modified Oswestry Disability Questionnaire (MODQ) was used for evaluation of functional disability. Measurements were done before and after the treatment. After treatment there were statistically significant improvements in pain severity, patient's and physician's global assessment, ROM and MODQ scores in both groups (P< 0.05). After the treatment there were statistically significant differences between the groups in lateral flexion measurements and MODQ scores (P< 0.05) except in pain severity, Modified Schober test, patient's and physician's global assessments (P> 0.05) in favor of those patients who received combined plaque laser therapy (group 2). Laser therapy applied with combined He-Ne and Ga-Al-As provides more improvements in lateral flexion measurements and disability of the patients, however no superiority of the two different laser devices to one another were detected on pain severity.

Effect of diode laser in the treatment of patients with nonspecific chronic low back pain: a randomized controlled trial.

PubMed

Vallone, Francesco; Benedicenti, Stefano; Sorrenti, Eugenio; Schiavetti, Irene; Angiero, Francesca

2014-09-01

Low back pain is a common, highly debilitating condition, whose severity is variable. This study evaluated the efficacy of treatment with Ga-Al-As diode laser (980 nm) with a large diameter spot (32 cm(2)), in association with exercise therapy, in reducing pain. The present study aimed to evaluate the pain reduction efficacy of treatment with the Ga-Al-As diode laser (980 nm) in combination with exercise therapy, in patients with chronic low back pain (CLBP). This study evaluated 100 patients with CLBP (mean age 60 years) who were randomly assigned to two groups. The laser plus exercises group (Laser+EX: 50 patients) received low-level laser therapy (LLLT) with a diode laser, 980 nm, with a specific handpiece [32 cm(2) irradiation spot size, power 20 W in continuous wave (CW), fluence 37.5J/cm(2), total energy per point 1200 J] thrice weekly, and followed a daily exercise schedule for 3 weeks (5 days/week). The exercises group (EX: 50 patients) received placebo laser therapy plus daily exercises. The outcome was evaluated on the visual analogue pain scale (VAS), before and after treatment. At the end of the 3 week period, the Laser+EX group showed a significantly greater decrease in pain than did the EX group. There was a significant difference between the two groups, with average Δ VAS scores of 3.96 (Laser+EX group) and 2.23 (EX group). The Student's t test demonstrated a statistically significant difference between the two groups, at p<0.001. This study demonstrated that the use of diode laser (980 nm) with large diameter spot size, in association with exercise therapy, appears to be effective. Such treatment might be considered a valid therapeutic option within rehabilitation programs for nonspecific CLBP.

Paresthesia-Free High-Density Spinal Cord Stimulation for Postlaminectomy Syndrome in a Prescreened Population: A Prospective Case Series.

PubMed

Sweet, Jennifer; Badjatiya, Anish; Tan, Daniel; Miller, Jonathan

2016-04-01

Spinal cord stimulation (SCS) traditionally is thought to require paresthesia, but there is evidence that paresthesia-free stimulation using high-density (HD) parameters might also be effective. The purpose of this study is to evaluate relative effectiveness of conventional, subthreshold HD, and sham stimulation on pain intensity and quality of life. Fifteen patients with response to conventional stimulation (60 Hz/350 μsec) were screened with a one-week trial of subthreshold HD (1200 Hz/200 μsec/amplitude 90% paresthesia threshold) and enrolled if there was at least 50% reduction on visual analog scale (VAS) for pain. Subjects were randomized into two groups and treated with four two-week periods of conventional, subthreshold HD, and sham stimulation in a randomized crossover design. Four of 15 patients responded to subthreshold HD stimulation. Mean VAS during conventional, subthreshold HD, and sham stimulation was 5.32 ± 0.63, 2.29 ± 0.41, and 6.31 ± 1.22, respectively. There was a significant difference in pain scores during the blinded crossover study of subthreshold HD vs. sham stimulation (p < 0.05, Student's t-test). Post hoc analysis revealed that subjects reported significantly greater attention to pain during conventional stimulation compared with subthreshold HD stimulation (p < 0.05, Student's t-test). All subjects reported a positive impression of change for subthreshold HD stimulation compared with conventional stimulation, and there was a trend toward greater likelihood for response to subthreshold HD stimulation in comparison with sham stimulation (p = 0.07, Fisher's exact test). At the end of the trial, all subjects elected to continue to receive subthreshold HD stimulation rather than conventional stimulation. Paresthesia are not necessary for pain relief using commercially available SCS devices, and may actually increase attention to pain. Subthreshold HD SCS represents a viable alternative to conventional stimulation among patients who are confirmed to have a clinical response to it. © 2015 International Neuromodulation Society.

Effects of the noncompetitive N-methyl-d-aspartate receptor antagonists ketamine and MK-801 on pain-stimulated and pain-depressed behaviour in rats.

PubMed

Hillhouse, T M; Negus, S S

2016-09-01

Pain is a significant public health concern, and current pharmacological treatments have problematic side effects and limited effectiveness. N-methyl-d-aspartate (NMDA) glutamate receptor antagonists have emerged as one class of candidate treatments for pain because of the significant contribution of glutamate signalling in nociceptive processing. This study compared effects of the NMDA receptor antagonists ketamine and MK-801 in assays of pain-stimulated and pain-depressed behaviour in rats. The nonsteroidal anti-inflammatory drug ketoprofen was examined for comparison as a positive control. Intraperitoneal injection of dilute acid served as an acute visceral noxious stimulus to stimulate a stretching response or depress intracranial self-stimulation (ICSS) in male Sprague-Dawley rats. Ketamine (1.0-10.0 mg/kg) blocked acid-stimulated stretching but failed to block acid-induced depression of ICSS, whereas MK-801 (0.01-0.1 mg/kg) blocked both acid-stimulated stretching and acid-induced depression of ICSS. These doses of ketamine and MK-801 did not alter control ICSS in the absence of the noxious stimulus; however, higher doses of ketamine (10 mg/kg) and MK-801 (0.32 mg/kg) depressed all behaviour. Ketoprofen (1.0 mg/kg) blocked both acid-induced stimulation of stretching and depression of ICSS without altering control ICSS. These results support further consideration of NMDA receptor antagonists as analgesics; however, some NMDA receptor antagonists are more efficacious at attenuating pain-depressed behaviours. NMDA receptor antagonists produce dissociable effects on pain-depressed behaviour. Provides evidence that pain-depressed behaviours should be considered and evaluated when determining the antinociceptive effects of NMDA receptor antagonists. © 2016 European Pain Federation - EFIC®

Efficacy of transverse tripolar stimulation for relief of chronic low back pain: results of a single center.

PubMed

Slavin, K V; Burchiel, K J; Anderson, V C; Cooke, B

1999-01-01

The goal of this study was to evaluate the efficacy of the transverse tripolar spinal cord stimulation system (TTS) in providing relief of low back pain in patients with chronic non-malignant pain. Transverse tripolar electrodes were implanted in the lower thoracic region (T(8-9) to T(12)-L(1)) in 10 patients with chronic neuropathic pain, all of whom reported a significant component of low back pain in combination with unilateral or bilateral leg pain. One patient reported inadequate pain relief during the trial and was not implanted with a permanent generator. A visual analogue scale of low back pain showed a nonsignificant decrease from 64 +/- 19 to 47 +/- 30 (p = 0.25; paired t test) after 1 month of stimulation. Similarly, functional disability evaluated using Oswestry Low Back Pain Questionnaire was not improved (p = 0. 46; paired t test). We conclude that chronic low back pain is not particularly responsive to the transverse stimulation provided by the TTS system. Copyright 2000 S. Karger AG, Basel

Influence of stimulus frequency and probe size on vibration-induced alleviation of acute orofacial pain.

PubMed

Hansson, P; Ekblom, A

1986-01-01

The pain-relieving effect of vibratory stimulation, using different stimulus parameters, and placebo stimulation in acute orofacial pain is reported. The influence of 10-, 100-, and 200-Hz vibrations on pain reduction was studied in 96 patients; two different probe sizes were used. 54 out of 76 patients, receiving vibrations at any of the above frequencies, reported relief of pain to some extent, while only 6 out of 20 patients receiving placebo treatment experienced pain alleviation. No significant differences were found between the different frequencies and probe sizes used regarding the pain-relieving effect. However, placebo stimulation was significantly less effective than any kind of vibratory stimulation. Induction time for pain relief was significantly shorter using the larger probe as compared to using the smaller probe, regardless of frequency. The results indicate that the vibratory frequency (10-200 Hz) for activation of pain-inhibitory mechanisms is not critical in acute orofacial pain. Also, spatial summation from vibration-sensitive afferents seems to be of importance for a fast activation of the inhibitory systems.

Relationships between skin temperature and temporal summation of heat and cold pain.

PubMed

Mauderli, Andre P; Vierck, Charles J; Cannon, Richard L; Rodrigues, Anthony; Shen, Chiayi

2003-07-01

Temporal summation of heat pain during repetitive stimulation is dependent on C nociceptor activation of central N-methyl-d-aspartate (NMDA) receptor mechanisms. Moderate temporal summation is produced by sequential triangular ramps of stimulation that control skin temperature between heat pulses but do not elicit distinct first and second pain sensations. Dramatic summation of second pain is produced by repeated contact of the skin with a preheated thermode, but skin temperature between taps is not controlled by this procedure. Therefore relationships between recordings of skin temperature and psychophysical ratings of heat pain were evaluated during series of repeated skin contacts. Surface and subcutaneous recordings of skin temperatures revealed efficient thermoregulatory compensation for heat stimulation at interstimulus intervals (ISIs) ranging from 2 to 8 s. Temporal summation of heat pain was strongly influenced by the ISIs and cannot be explained by small increases in skin temperature between taps or by heat storage throughout a stimulus series. Repetitive brief contact with a precooled thermode was utilized to evaluate whether temporal summation of cold pain occurs, and if so, whether it is influenced by skin temperature. Surface and subcutaneous recordings of skin temperature revealed a sluggish thermoregulatory compensation for repetitive cold stimulation. In contrast to heat stimulation, skin temperature did not recover between cold stimuli throughout ISIs of 3-8 s. Psychophysically, repetitive cold stimulation produced an aching pain sensation that progressed gradually and radiated beyond the site of stimulation. The magnitude of aching pain was well related to skin temperature and thus appeared to be established primarily by peripheral factors.

Problems and complications of full-face carbon dioxide laser resurfacing for pathological lesions of the skin.

PubMed

Read-Fuller, Andrew M; Yates, David M; Vu, David D; Hoopman, John E; Finn, Richard A

2017-01-01

Facial resurfacing with a CO 2 laser has been used for treatment of pathologic lesions and for cosmetic purposes. Postoperative complications and problems after laser resurfacing include infections, acneiform lesions, and pigment changes. This retrospective study describes the most common problems and complications in 105 patients and assesses postoperative pain in 38 patients. All patients received CO 2 laser resurfacing for treatment of malignant/premalignant lesions and had postoperative follow-up to assess problems and complications. Some had follow-up to assess postoperative pain. All patients had Fitzpatrick I-III skin types and underwent the same perioperative care regimen. There were 11 problems and 2 complications. Problems included infection, acneiform lesion/milia, and uncontrolled postoperative pain. Complications included hyperpigmentation. Among the postoperative pain group, 53% reported no pain and the rest had mild or moderate pain. Complications are rare. Infection and acneiform lesions/milia were the most common problems, as previously reported. Most patients do not experience postoperative pain. Copyright © 2016 Elsevier Inc. All rights reserved.

Nonpainful remote electrical stimulation alleviates episodic migraine pain.

PubMed

Yarnitsky, David; Volokh, Lana; Ironi, Alon; Weller, Boaz; Shor, Merav; Shifrin, Alla; Granovsky, Yelena

2017-03-28

To evaluate the efficacy of remote nonpainful electrical upper arm skin stimulation in reducing migraine attack pain. This is a prospective, double-blinded, randomized, crossover, sham-controlled trial. Migraineurs applied skin electrodes to the upper arm soon after attack onset for 20 minutes, at various pulse widths, and refrained from medications for 2 hours. Patients were asked to use the device for up to 20 attacks. In 71 patients (299 treatments) with evaluable data, 50% pain reduction was obtained for 64% of participants based on best of 200-μs, 150-μs, and 100-μs pulse width stimuli per individual vs 26% for sham stimuli. Greater pain reduction was found for active stimulation vs placebo; for those starting at severe or moderate pain, reduction (1) to mild or no pain occurred in 58% (25/43) of participants (66/134 treatments) for the 200-μs stimulation protocol and 24% (4/17; 8/29 treatments) for placebo ( p = 0.02), and (2) to no pain occurred in 30% (13/43) of participants (37/134 treatments) and 6% (1/17; 5/29 treatments), respectively ( p = 0.004). Earlier application of the treatment, within 20 minutes of attack onset, yielded better results: 46.7% pain reduction as opposed to 24.9% reduction when started later ( p = 0.02). Nonpainful remote skin stimulation can significantly reduce migraine pain, especially when applied early in an attack. This is presumably by activating descending inhibition pathways via the conditioned pain modulation effect. This treatment may be proposed as an attractive nonpharmacologic, easy to use, adverse event free, and inexpensive tool to reduce migraine pain. NCT02453399. This study provides Class III evidence that for patients with an acute migraine headache, remote nonpainful electrical stimulation on the upper arm skin reduces migraine pain. © 2017 American Academy of Neurology.

[Subcutaneous stimulation as additional therapy to spinal cord stimulation in a post-laminectomy syndrome patient].

PubMed

Akbaş, Mert; Yeğin, Mehmet Arif; Özdemir, İrem; Göksu, Ethem; Akyüz, Mahmut

2016-01-01

Spinal cord stimulation as treatment of chronic low back pain via neuromodulation has been frequently performed in recent years. The dorsal column is stimulated by an electrode placed at the epidural region. In the case presently described, subcutaneous lead was implanted in a patient with failed back syndrome after spinal cord stimulation was inadequate to treat back and gluteal pain. A 65-year-old male had undergone surgery to treat lumbar disc herniation, after which he received physical therapy and multiple steroid injections due to unrelieved pain. He was admitted to the pain clinic with pain radiating to right gluteal muscle and leg. Spinal cord stimulation was performed and, as pain was not relieved, subcutaneous lead was applied to the right cluneal nerve distribution. Following treatment, the patient scored 1-2 on visual analog scale. Pain had been reduced by over 80%. Octad electrode was placed between T8 and T10 vertebrae after Tuohy needle was introduced to intervertebral area between L1 and L2. Paresthesia occurred in the right extremity. Boundaries were determined by area of right gluteal region in which paresthesia did not occur. Octad electrode was placed subcutaneously after vertical line was drawn from center point. Paresthesia occurred throughout the region. Pulse wave was 390-450 msec; frequency was 10-30 Hz. Subcutaneous electrode replacement is effective additional therapy when pain is not relieved by spinal cord stimulation.

Continuous-wave vs. pulsed infrared laser stimulation of the rat prostate cavernous nerves

NASA Astrophysics Data System (ADS)

Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2011-03-01

Optical nerve stimulation has recently been developed as an alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuouswave (CW) infrared laser radiation, for potential diagnostic applications. A Thulium fiber laser (λ = 1870 nm) was used for non-contact optical stimulation of the rat prostate cavernous nerves, in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, was achieved with the laser operating in either CW mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation was observed to be primarily dependent on a threshold nerve temperature (42-45 °C), not an incident fluence, as previously reported. CW optical nerve stimulation provides a significantly faster ICP response time using a laser with lower power output than pulsed stimulation. CW optical nerve stimulation may therefore represent an alternative mode of stimulation for intra-operative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

Efficacy of transverse tripolar spinal cord stimulator for the relief of chronic low back pain from failed back surgery.

PubMed

Buvanendran, Asokumar; Lubenow, Timothy J

2008-01-01

Failed back surgery syndrome is a common clinical entity for which spinal cord stimulation has been found to be an effective mode of analgesia, but with variable success rates. To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and therefore provide greater analgesia to the back. Case report. We describe a 42-year-old female with failed back surgery syndrome that had greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads, advanced to the T7-T10 vertebral bodies. Tripolar stimulation pattern resulted in more than 70% pain relief in this patient during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain relief. After implantation of a permanent tripolar electrode system with a single rechargeable battery, the pain relief was maintained for one year. This is case report describing a case of a patient with chronic low back pain with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar system consists of a central cathode surrounded by anodes, using 3 leads. This arrangement may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation and provide analgesia to the lower back.

Spinal Cord Stimulation (SCS) and Functional Magnetic Resonance Imaging (fMRI): Modulation of Cortical Connectivity With Therapeutic SCS.

PubMed

Deogaonkar, Milind; Sharma, Mayur; Oluigbo, Chima; Nielson, Dylan M; Yang, Xiangyu; Vera-Portocarrero, Louis; Molnar, Gregory F; Abduljalil, Amir; Sederberg, Per B; Knopp, Michael; Rezai, Ali R

2016-02-01

The neurophysiological basis of pain relief due to spinal cord stimulation (SCS) and the related cortical processing of sensory information are not completely understood. The aim of this study was to use resting state functional magnetic resonance imaging (rs-fMRI) to detect changes in cortical networks and cortical processing related to the stimulator-induced pain relief. Ten patients with complex regional pain syndrome (CRPS) or neuropathic leg pain underwent thoracic epidural spinal cord stimulator implantation. Stimulation parameters associated with "optimal" pain reduction were evaluated prior to imaging studies. Rs-fMRI was obtained on a 3 Tesla, Philips Achieva MRI. Rs-fMRI was performed with stimulator off (300TRs) and stimulator at optimum (Opt, 300 TRs) pain relief settings. Seed-based analysis of the resting state functional connectivity was conducted using seeds in regions established as participating in pain networks or in the default mode network (DMN) in addition to the network analysis. NCUT (normalized cut) parcellation was used to generate 98 cortical and subcortical regions of interest in order to expand our analysis of changes in functional connections to the entire brain. We corrected for multiple comparisons by limiting the false discovery rate to 5%. Significant differences in resting state connectivity between SCS off and optimal state were seen between several regions related to pain perception, including the left frontal insula, right primary and secondary somatosensory cortices, as well as in regions involved in the DMN, such as the precuneus. In examining changes in connectivity across the entire brain, we found decreased connection strength between somatosensory and limbic areas and increased connection strength between somatosensory and DMN with optimal SCS resulting in pain relief. This suggests that pain relief from SCS may be reducing negative emotional processing associated with pain, allowing somatosensory areas to become more integrated into default mode activity. SCS reduces the affective component of pain resulting in optimal pain relief. Study shows a decreased connectivity between somatosensory and limbic areas associated with optimal pain relief due to SCS. © 2015 International Neuromodulation Society.

Does experimental pain affect auditory processing of speech-relevant signals? A study in healthy young adults.

PubMed

Sapir, Shimon; Pud, Dorit

2008-01-01

To assess the effect of tonic pain stimulation on auditory processing of speech-relevant acoustic signals in healthy pain-free volunteers. Sixty university students, randomly assigned to either a thermal pain stimulation (46 degrees C/6 min) group (PS) or no pain stimulation group (NPS), performed a rate change detection task (RCDT) involving sinusoidally frequency-modulated vowel-like signals. Task difficulty was manipulated by changing the rate of the modulated signals (henceforth rate). Perceived pain intensity was evaluated using a visual analog scale (VAS) (0-100). Mean pain rating was approximately 33 in the PS group and approximately 3 in the NPS group. Pain stimulation was associated with poorer performance on the RCDT, but this trend was not statistically significant. Performance worsened with increasing rate of signal modulation in both groups (p < 0.0001), with no pain by rate interaction. The present findings indicate a trend whereby mild or moderate pain appears to affect auditory processing of speech-relevant acoustic signals. This trend, however, was not statistically significant. It is possible that more intense pain would yield more pronounced (deleterious) effects on auditory processing, but this needs to be verified empirically.

Clinical Outcomes of 1 kHz Subperception Spinal Cord Stimulation in Implanted Patients With Failed Paresthesia-Based Stimulation: Results of a Prospective Randomized Controlled Trial.

PubMed

North, James M; Hong, Kyung-Soo Jason; Cho, Philip Young

2016-10-01

Pain relief via spinal cord stimulation (SCS) has historically revolved around producing paresthesia to replace pain, with success measured by the extent of paresthesia-pain overlap. In a recent murine study, by Shechter et al., showed the superior efficacy of high frequency SCS (1 kHz and 10 kHz) at inhibiting the effects of mechanical hypersensitivity compared to sham or 50 Hz stimulation. In the same study, authors report there were no differences in efficacy between 1 kHz and 10 kHz delivered at subperception stimulation strength (80% of motor threshold). Therefore, we designed a randomized, 2 × 2 crossover study of low frequency supra-perception SCS vs. subperception SCS at 1 kHz frequency in order to test whether subperception stimulation at 1 kHz was sufficient to provide effective pain relief in human subjects. Twenty-two subjects with SCS, and inadequate pain relief based on numeric pain rating scale (NPRS) scores (>5) were enrolled, and observed for total of seven weeks (three weeks of treatment, one week wash off, and another three weeks of treatment). Subjects were asked to rate their pain on NPRS as a primary efficacy variable, and complete the Oswestry Disability Index (ODI) and Patient's Global Impression of Change (PGIC) as secondary outcome measures. Out of 22 subjects that completed the study, 21 subjects (95%) reported improvements in average, best, and worst pain NPRS scores. All NPRS scores were significantly lower with subperception stimulation compared to paresthesia-based stimulation (p < 0.01, p < 0.05, and p < 0.05, respectively). As with NPRS scores, the treatment effect of subperception stimulation was significantly greater than that of paresthesia based stimulation on ODI scores (p = 3.9737 × 10 -5 ) and PGIC scores (p = 3.0396 × 10 -5 ). © 2016 International Neuromodulation Society.

Assessment of feasibility and efficacy of Class IV laser therapy for postoperative pain relief in off-pump coronary artery bypass surgery patients: A pilot study

PubMed Central

Karlekar, Anil; Bharati, Saswata; Saxena, Ravindra; Mehta, Kanchan

2015-01-01

Background: Laser therapy, for its established analgesic properties with minimal side effects, has been used for the treatment of chronic pain. However, it has not been used for the treatment of acute postoperative pain. This pilot study was designed to assess the feasibility and efficacy of Class IV laser on postoperative pain relief following off-pump coronary artery bypass graft (OPCABG) surgery, as a component of multimodal analgesia (MMA) technique. Methods: This open observational prospective study comprised of 100 adult patients (84 male, 16 female) who underwent OPCABG through sternotomy. For postoperative analgesia, they were subjected to laser therapy subjected to laser therapy in addition to the standard institutional pain management protocol comprising of IV infusion/bolus of tramadol and paracetamol and fentanyl bolus as rescue analgesic. Pain intensity was measured by Verbal Rating Scale (VRS). The laser therapy was scheduled as once a day regime for three consecutive postoperative days (PODs) starting on POD 1, 30 min following tracheal extubation. The subsequent laser applications were also scheduled at the same time of the day as on day 1 if VRS was ≥5. 10 W Class IV laser was applied over 150 cm2 sternal wound area for 150 s. VRS was used to assess pain severity and was recorded for statistical analysis using Friedman Test. Results: The mean (standard deviation [SD]) VRS of all the 100 patients just before application of the first dose of laser was 7.31 (0.94) while on MMT; the same fell to 4.0 (1.279) and 3.40 (2.697) at 1 h and 24 h respectively following first dose of laser. The change of VRS over first 24 h among all the 100 patients was statistically significant (P = 0.000). Laser was re-applied in 40 patients whose VRS was ≥5 (mean [SD] – 6.38 [0.868]) at 24th h. After receiving the 2nd dose of laser the VRS scores fell significantly (P = 0.000) and became 0 at 54th h. No patients required 3rd dose of the laser. No patient required rescue analgesic while on laser therapy. Conclusion: Class IV laser can be an effective technique for postoperative analgesia following OPCABG surgery through sternotomy when included as a component of MMA technique. PMID:26139735

Role of laser fluence in protein synthesis of cultured DRG neurons following low-level laser irradiation

NASA Astrophysics Data System (ADS)

Zheng, Liqin; Qiu, Caimin; Wang, Yuhua; Zeng, Yixiu; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

2014-11-01

Low-level lasers have been used to relieve pain in clinical for many years. But the mechanism is not fully clear. In animal models, nitric oxide (NO) has been reported involving in the transmission and modulation of nociceptive signals. So the objective of this study was to establish whether low-level laser with different fluence could stimulate the production of nitric oxide synthese (NOS), which produces NO in cultured primary dorsal root ganglion neurons (DRG neurons). The primary DRG neurons were isolated from healthy Sprague Dawley rats (8-12 weeks of age) and spread on 35 mm culture dishes specially used for confocal microscopy. 24 hours after spreading, cells were irradiated with 658 nm laser for two consecutive days at the energy density of 20, 40, 60 and 80 mJ·cm-2 respectively. Control groups were not exposed to the laser, but were kept under the same conditions as the irradiated ones. The synthesis of NOS after laser irradiation was detected by immunofluorescence assay, and the changes of NOS were evaluated using confocal microscopy and Image J software. The results showed that all the laser fluence could promote the production of NOS in DRG neurons, especially the 60 mJ·cm-2 . These results demonstrated that low-level laser irradiation could modify protein synthesis in a dose- or fluence- dependent manner, and indicated that low-level laser irradiation might achieve the analgesic effect through modulation of NO production.

The effect of Laser and taping on pain, functional status and quality of life in patients with fibromyalgia syndrome: A placebo- randomized controlled clinical trial.

PubMed

Vayvay, Emre Serdar; Tok, Damla; Turgut, Elif; Tunay, Volga Bayrakci

2016-01-01

Conservative treatments have been proved to be effective to control pain and optimize function in fibromyalgia, however there is need for scientific evidence to make better clinical application across various physiotherapy applications. The aim of this study was to investigate the effects of Laser and taping applications on pain, flexibility, anxiety, depression, functional status and quality of life in patients with fibromyalgia syndrome. Forty-five female patients with fibromyalgia syndrome were included to the study and randomly allocated into three treatment groups; Laser (n= 15), placebo Laser (n= 15), and taping applications (n= 15). Visual analogue scale for pain intensity, trunk flexibility, Fibromyalgia Impact Questionnaire for functional status, Short Form 36 Questionnaire for quality of life and health status, and Beck Depression Inventory for anxiety level were evaluated before and after three weeks interventions. There were decreased pain severity in activity (p= 0.028), anxiety level (p= 0.01) and improved general health status, quality of life (p= 0.01) found at Laser group, whereas there were increased trunk flexibility, flexion (p= 0.03), extension (p= 0.02) found at taping group. After interventions, there were decreased pain severity for whole groups at night for Laser group (p= 0.04), placebo Laser group (p= 0.001), taping group (p= 0.01) and improved functional status found for Laser group (p= 0.001), placebo Laser group (p= 0.001), taping group (p= 0.01). Kinesiotape application had a similar effect on parameters in FMS patient, so this method could be preferred instead of Laser application for rehabilitation program.

Parameters in fractional laser assisted delivery of topical anesthetics: Role of laser type and laser settings.

PubMed

Meesters, Arne A; Nieboer, Marilin J; Kezic, Sanja; de Rie, Menno A; Wolkerstorfer, Albert

2018-05-07

Efficacy of topical anesthetics can be enhanced by pretreatment of the skin with ablative fractional lasers. However, little is known about the role of parameters such as laser modality and laser density settings in this technique. Aims of this study were to compare the efficacy of pretreatment with two different ablative fractional laser modalities, a CO 2 laser and an Er:YAG laser, and to assess the role of laser density in ablative fractional laser assisted topical anesthesia. In each of 15 healthy subjects, four 10 × 10 mm test regions on the back were randomized to pretreatment (70-75 μm ablation depth) with CO 2 laser at 5% density, CO 2 laser at 15% density, Er:YAG laser at 5% density or Er:YAG laser at 15% density. Articaine hydrochloride 40 mg/ml + epinephrine 10 μg/ml solution was applied under occlusion to all four test regions. After 15 minutes, a pass with the CO 2 laser (1,500 μm ablation depth) was administered as pain stimulus to each test region. A reference pain stimulus was given on unanesthetized skin. The main outcome parameter, pain, was scored on a 0-10 visual analogue scale (VAS) after each pain stimulus. Median VAS scores were 1.50 [CO 2 5%], 0.50 [CO 2 15%], 1.50 [Er:YAG 5%], 0.43 [Er:YAG 15%], and 4.50 [unanesthetized reference]. VAS scores for all pretreated test regions were significantly lower compared to the untreated reference region (P < 0.01). We found no significant difference in VAS scores between the CO 2 and the Er:YAG laser pretreated regions. However, VAS scores were significantly lower at 15% density compared to 5% density for both for the CO 2 laser (P < 0.05) and the Er:YAG laser (P < 0.01). Pretreatment with the CO 2 laser was considered slightly more painful than pretreatment with Er:YAG laser by the subjects. Fractional laser assisted topical anesthesia is effective even with very low energy settings and an occlusion time of only 15 minutes. Both the CO 2 laser and the Er:YAG laser can be used to assist topical anesthesia although the CO 2 laser pretreatment is experienced as more painful. In our study settings, using articaine/epinephrine solution and an occlusion time of 15 minutes, a density of 15% was more effective than 5%. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Subcutaneous stimulation as an additional therapy to spinal cord stimulation for the treatment of lower limb pain and/or back pain: a feasibility study.

PubMed

Hamm-Faber, Tanja E; Aukes, Hans A; de Loos, Frank; Gültuna, Ismail

2012-01-01

The objective of this study was to demonstrate the efficacy of subcutaneous stimulation (SubQ) as an additional therapy in patients with failed back surgery syndrome (FBSS) with chronic refractory pain, for whom spinal cord stimulation (SCS) was unsuccessful in treating low back pain. Case series. FBSS patients with chronic limb and/or low back pain whose conventional therapies had failed received a combination of SCS (8-contact Octad lead) and/or SubQ (4-contact Quad Plus lead(s)). Initially leads were placed in the epidural space for SCS for a trial stimulation to assess response to suppression of limb and low back pain. Where SCS alone was insufficient in treating lower back pain, leads were placed superficially in the subcutaneous tissue of the lower back, directly in the middle of the pain area. A pulse generator was implanted if patients reported more than 50% pain relief during the trial period. Pain intensity for limb and lower back pain was scored separately, using visual analog scale (VAS). Pain and Quebec Back Pain Disability Scale (QBPDS) after 12-month treatment were compared with pain and QBPDS at baseline. Eleven FBSS patients, five male and six female (age: 51 ± 8 years; mean ± SD), in whom SCS alone was insufficient in treating lower back pain, were included. In nine cases, SubQ was used in combination with SCS to treat chronic lower back and lower extremity pain. In two cases only SubQ was used to treat lower back pain. SCS significantly reduced limb pain after 12 months (VAS(bl) : 62 ± 14 vs. VAS(12m) : 20 ± 11; p= 0.001, N= 8). SubQ stimulation significantly reduced low back pain after 12 months (VAS(bl) : 62 ± 13.0 vs. VAS(12m) : 32 ± 16; p= 0.0002, N= 10). Overall pain medication was reduced by more than 70%. QBPDS improved from 61 ± 15 to 49 ± 12 (p= 0.046, N= 10). Furthermore, we observed that two patients returned to work. SubQ may be an effective additional treatment for chronic low back pain in patients with FBSS for whom SCS alone is insufficient in alleviating their pain symptoms. © 2011 International Neuromodulation Society.

A pilot study of the tolerability and effects of high-definition transcranial direct current stimulation (HD-tDCS) on pain perception.

PubMed

Borckardt, Jeffrey J; Bikson, Marom; Frohman, Heather; Reeves, Scott T; Datta, Abhishek; Bansal, Varun; Madan, Alok; Barth, Kelly; George, Mark S

2012-02-01

Several brain stimulation technologies are beginning to evidence promise as pain treatments. However, traditional versions of 1 specific technique, transcranial direct current stimulation (tDCS), stimulate broad regions of cortex with poor spatial precision. A new tDCS design, called high definition tDCS (HD-tDCS), allows for focal delivery of the charge to discrete regions of the cortex. We sought to preliminarily test the safety and tolerability of the HD-tDCS technique as well as to evaluate whether HD-tDCS over the motor cortex would decrease pain and sensory experience. Twenty-four healthy adult volunteers underwent quantitative sensory testing before and after 20 minutes of real (n = 13) or sham (n = 11) 2 mA HD-tDCS over the motor cortex. No adverse events occurred and no side effects were reported. Real HD-tDCS was associated with significantly decreased heat and cold sensory thresholds, decreased thermal wind-up pain, and a marginal analgesic effect for cold pain thresholds. No significant effects were observed for mechanical pain thresholds or heat pain thresholds. HD-tDCS appears well tolerated, and produced changes in underlying cortex that are associated with changes in pain perception. Future studies are warranted to investigate HD-tDCS in other applications, and to examine further its potential to affect pain perception. This article presents preliminary tolerability and efficacy data for a new focal brain stimulation technique called high definition transcranial direct current stimulation. This technique may have applications in the management of pain. Copyright © 2012. Published by Elsevier Inc.

Involvement of neutrophils and interleukin-18 in nociception in a mouse model of muscle pain.

PubMed

Yoshida, Shinichirou; Hagiwara, Yoshihiro; Tsuchiya, Masahiro; Shinoda, Masamichi; Koide, Masashi; Hatakeyama, Hiroyasu; Chaweewannakorn, Chayanit; Yano, Toshihisa; Sogi, Yasuhito; Itaya, Nobuyuki; Sekiguchi, Takuya; Yabe, Yutaka; Sasaki, Keiichi; Kanzaki, Makoto; Itoi, Eiji

2018-01-01

Muscle pain is a common condition that relates to various pathologies. Muscle overuse induces muscle pain, and neutrophils are key players in pain production. Neutrophils also play a central role in chronic pain by secreting interleukin (IL)-18. The aim of this study was to investigate the involvement of neutrophils and IL-18 in a mouse model of muscle pain. The right hind leg muscles of BALB/c mice were stimulated electrically to induce excessive muscle contraction. The left hind leg muscles were not stimulated. The pressure pain threshold, number of neutrophils, and IL-18 levels were investigated. Furthermore, the effects of the IL-18-binding protein and Brilliant Blue G on pain were investigated. In stimulated muscles, pressure pain thresholds decreased, and neutrophil and IL-18 levels increased compared with that in non-stimulated muscles. The administration of IL-18-binding protein and Brilliant Blue G attenuated hyperalgesia caused by excessive muscle contraction. These results suggest that increased IL-18 secretion from larger numbers of neutrophils elicits mechanical hyperalgesia.

Magnetoencephalographic study of event-related fields and cortical oscillatory changes during cutaneous warmth processing.

PubMed

An, Kyung-Min; Lim, Sanghyun; Lee, Hyun Joon; Kwon, Hyukchan; Kim, Min-Young; Gohel, Bakul; Kim, Ji-Eun; Kim, Kiwoong

2018-05-01

Thermoreception is an important cutaneous sense, which plays a role in the maintenance of our body temperature and in the detection of potential noxious heat stimulation. In this study, we investigated event-related fields (ERFs) and neural oscillatory activities, which were modulated by warmth stimulation. We developed a warmth stimulator that could elicit a warmth sensation, without pain or tactile sensation, by using a deep-penetrating 980-nm diode laser. The index finger of each participant (n = 24) was irradiated with the laser warmth stimulus, and the cortical responses were measured using magnetoencephalography (MEG). The ERFs and oscillatory responses had late latencies (∼1.3 s and 1.0-1.5 s for ERFs and oscillatory responses, respectively), which could be explained by a slow conduction velocity of warmth-specific C-fibers. Cortical sources of warmth-related ERFs were seen in the bilateral primary and secondary somatosensory cortices (SI and SII), posterior part of the anterior cingulate cortex (pACC), ipsilateral primary motor, and premotor cortex. Thus, we suggested that SI, SII, and pACC play a role in processing the warmth sensation. Time-frequency analysis demonstrated the suppression of the alpha (8-13 Hz) and beta (18-23 Hz) band power in the bilateral sensorimotor cortex. We proposed that the suppressions in alpha and beta band power are involved in the automatic response to the input of warmth stimulation and sensorimotor interactions. The delta band power (1-4 Hz) increased in the frontal, temporal, and cingulate cortices. The power changes in delta band might be related with the attentional processes during the warmth stimulation. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Peripheral nerve field stimulation in chronic abdominal pain.

PubMed

Paicius, Richard M; Bernstein, Clifford A; Lempert-Cohen, Cheryl

2006-07-01

Spinal Cord Stimulation (SCS) has become an accepted therapeutic modality for the treatment of intractable pain syndromes, primarily used today in the settings of failed back surgery syndrome, neuropathic back and limb pain. The use of spinal cord stimulators for peripheral nerve field electrostimulation is becoming increasingly recognized as a safe, effective alternative for chronic pain conditions that are refractory to medical management and do not respond to traditional dorsal column stimulation. Advances in technology have allowed for minimally invasive percutaneous placement of multipolar leads with complex programmable systems to provide patient- controlled relief of pain in precisely targeted regions. With these improvements in hardware, the use of Peripheral Nerve Field Stimulation (PNFS) appears to have an untapped potential for providing patients with pain relief for a wider range of underlying conditions than was previously believed possible. We present three cases, each with a different etiology of chronic abdominal pain: one with inguinal neuralgia, one with chronic pancreatitis, and one with pain following liver transplant. Each patient was refractory to conventional medical approaches. For all three patients, PNFS provided significant relief from pain, enabling patients to decrease or discontinue their opioid medications and to enjoy significant improvement in their quality of life. We conclude that PNFS is a safe, effective and minimally invasive treatment that may be used successfully for a wide variety of indications including chronic abdominal pain.

Closed-Loop Deep Brain Stimulation for Refractory Chronic Pain

PubMed Central

Shirvalkar, Prasad; Veuthey, Tess L.; Dawes, Heather E.; Chang, Edward F.

2018-01-01

Pain is a subjective experience that alerts an individual to actual or potential tissue damage. Through mechanisms that are still unclear, normal physiological pain can lose its adaptive value and evolve into pathological chronic neuropathic pain. Chronic pain is a multifaceted experience that can be understood in terms of somatosensory, affective, and cognitive dimensions, each with associated symptoms and neural signals. While there have been many attempts to treat chronic pain, in this article we will argue that feedback-controlled ‘closed-loop’ deep brain stimulation (DBS) offers an urgent and promising route for treatment. Contemporary DBS trials for chronic pain use “open-loop” approaches in which tonic stimulation is delivered with fixed parameters to a single brain region. The impact of key variables such as the target brain region and the stimulation waveform is unclear, and long-term efficacy has mixed results. We hypothesize that chronic pain is due to abnormal synchronization between brain networks encoding the somatosensory, affective and cognitive dimensions of pain, and that multisite, closed-loop DBS provides an intuitive mechanism for disrupting that synchrony. By (1) identifying biomarkers of the subjective pain experience and (2) integrating these signals into a state-space representation of pain, we can create a predictive model of each patient's pain experience. Then, by establishing how stimulation in different brain regions influences individual neural signals, we can design real-time, closed-loop therapies tailored to each patient. While chronic pain is a complex disorder that has eluded modern therapies, rich historical data and state-of-the-art technology can now be used to develop a promising treatment. PMID:29632482

Assessment of the Therapeutic Effectiveness of Deep Electromagnetic Stimulation in Patients with Chronic Low Back Pain.

PubMed

Przedborska, Agnieszka; Misztal, Małgorzata; Raczkowski, Jan W

2015-10-01

The study presents the results of the application of deep electromagnetic stimulation (DEMS) therapy in the treatment of low back pain. The study aimed to evaluate and compare pain severity before and after deep electromagnetic stimulation sessions and to assess persistence of the analgesic effect and identify factors which influenced it significantly. The study enrolled a series of 105 consecutive patients with chronic low back pain who underwent a series of 10 sessions of deep electromagnetic stimulation. The effectiveness of the therapy was assessed according to VAS and Laitinen scores. Risk factors significantly affecting the stability of analgesic effect after DEMS therapy were identified using the Cox regression model. Statistically significant pain relief was observed after deep electromagnetic therapy. Both the Laitinen and VAS scales demonstrated the reduction in pain intensity by half (Me (IQR): 6 (5-9) before the therapy vs. 3 (24) afterwards, p<0.0001 for Laitinen scale and 7 (6-8) before vs. 3 (2-5) after the therapy, p<0.0001 for VAS). During 12-month follow up, pain recurred in 84 (80%) patients. Pain recurrence within a year after the therapy was stimulated in a statistically significant manner by pain duration (HR=1.032, 95% CI: 0.988-1.078; p=0.032) and the co-occurrence of degenerative joint disease (HR=5.521, 95%CI: 2.905-10.493; p=0.001). 1. Deep electromagnetic stimulation is an effective treatment in patients with chronic low back pain. 2. The degree of effectiveness of this modality in the longer term depends on the cause and duration of pain.

Neurostimulation for the treatment of axial back pain: a review of mechanisms, techniques, outcomes, and future advances.

PubMed

Deer, Timothy; Pope, Jason; Hayek, Salim; Narouze, Samer; Patil, Parag; Foreman, Robert; Sharan, Ashwini; Levy, Robert

2014-10-01

The use of spinal cord stimulation (SCS) is well established in the treatment of neuropathic pain. This procedure has been approved in the United States for neuropathic pain of the trunk and limbs from various conditions. International use is variable based on governmental policy. Most studies showing efficacy have focused on pain primarily in the limbs for such conditions as complex regional pain syndrome (CRPS), sciatica, radiculitis, ischemic limb pain, and peripheral neuropathy. Data on success in neuropathic pain of the trunk and particularly of the axial back are limited. New understanding about the targets of neuromodulation and their treatment with novel neurostimulation approaches has led to a new dawn of enthusiasm for spinal cord stimulation for axial low back pain. The authors review mechanisms, current and future targets, techniques, and their outcomes for treating axial back pain with neurostimulation. The paper discusses many newer methods and targets that may substantially improve results for the treatment of this patient group. The continuing evolution of technology and new data may well change these recommendations over time and regular updates of this manuscript will be critical moving forward. Improved technology and a better understanding of the goals of stimulation have led to a new ability to stimulate the axial low back and increase the effectiveness of these therapies to reduce pain. New paddle lead constructs, percutaneous paddle lead introduction, and other new technologies have led to an increased number of potential candidates for spinal cord stimulation. Optimizing the application of neurostimulation for chronic axial back pain will depend upon answering questions relating to patient selection, implantation technique, and stimulation parameters. © 2014 International Neuromodulation Society.

A novel model of inflammatory pain in human skin involving topical application of sodium lauryl sulfate.

PubMed

Petersen, L J; Lyngholm, A M; Arendt-Nielsen, L

2010-09-01

Sodium lauryl sulfate (SLS) is a known irritant. It releases pro-inflammatory mediators considered pivotal in inflammatory pain. The sensory effects of SLS in the skin remain largely unexplored. In this study, SLS was evaluated for its effect on skin sensory functions. Eight healthy subjects were recruited for this study. Skin sites were randomized to topical SLS 0.25, 0.5, 1, 2% and vehicle for 24 h. Topical capsaicin 1% was applied for 30 min at 24 h after SLS application. Assessments included laser Doppler imaging of local vasodilation and flare reactions, rating of spontaneous pain, assessment of primary thermal and tactile hyperalgesia, and determination of secondary dynamic and static hyperalgesia. SLS induced significant and dose-dependent local inflammation and primary hyperalgesia to tactile and thermal stimulation at 24 h after application, with SLS 2% treatment eliciting results comparable to those observed following treatment with capsaicin 1%. SLS induced no spontaneous pain, small areas of flare, and minimal secondary hyperalgesia. The primary hyperalgesia vanished within 2-3 days, whereas the skin inflammation persisted and was only partly normalized by Day 6. SLS induces profound perturbations of skin sensory functions lasting 2-3 days. SLS-induced inflammation may be a useful model for studying the mechanisms of inflammatory pain.

Pulse-train Stimulation of Primary Somatosensory Cortex Blocks Pain Perception in Tail Clip Test

PubMed Central

Lee, Soohyun; Hwang, Eunjin; Lee, Dongmyeong

2017-01-01

Human studies of brain stimulation have demonstrated modulatory effects on the perception of pain. However, whether the primary somatosensory cortical activity is associated with antinociceptive responses remains unknown. Therefore, we examined the antinociceptive effects of neuronal activity evoked by optogenetic stimulation of primary somatosensory cortex. Optogenetic transgenic mice were subjected to continuous or pulse-train optogenetic stimulation of the primary somatosensory cortex at frequencies of 15, 30, and 40 Hz, during a tail clip test. Reaction time was measured using a digital high-speed video camera. Pulse-train optogenetic stimulation of primary somatosensory cortex showed a delayed pain response with respect to a tail clip, whereas no significant change in reaction time was observed with continuous stimulation. In response to the pulse-train stimulation, video monitoring and local field potential recording revealed associated paw movement and sensorimotor rhythms, respectively. Our results show that optogenetic stimulation of primary somatosensory cortex at beta and gamma frequencies blocks transmission of pain signals in tail clip test. PMID:28442945

Effects of the noncompetitive N-methyl-D-aspartate receptor antagonists ketamine and MK-801 on pain-stimulated and pain-depressed behaviour in rats

PubMed Central

Hillhouse, T.M.; Negus, S.S.

2017-01-01

Background Pain is a significant public health concern, and current pharmacological treatments have problematic side effects and limited effectiveness. N-methyl-D-aspartate (NMDA) glutamate receptor antagonists have emerged as one class of candidate treatments for pain because of the significant contribution of glutamate signalling in nociceptive processing. Methods This study compared effects of the NMDA receptor antagonists ketamine and MK-801 in assays of pain-stimulated and pain-depressed behaviour in rats. The nonsteroidal anti-inflammatory drug ketoprofen was examined for comparison as a positive control. Intraperitoneal injection of dilute acid served as an acute visceral noxious stimulus to stimulate a stretching response or depress intracranial self-stimulation (ICSS) in male Sprague–Dawley rats. Results Ketamine (1.0–10.0 mg/kg) blocked acid-stimulated stretching but failed to block acid-induced depression of ICSS, whereas MK-801 (0.01–0.1 mg/kg) blocked both acid-stimulated stretching and acid-induced depression of ICSS. These doses of ketamine and MK-801 did not alter control ICSS in the absence of the noxious stimulus; however, higher doses of ketamine (10 mg/kg) and MK-801 (0.32 mg/kg) depressed all behaviour. Ketoprofen (1.0 mg/kg) blocked both acid-induced stimulation of stretching and depression of ICSS without altering control ICSS. Conclusion These results support further consideration of NMDA receptor antagonists as analgesics; however, some NMDA receptor antagonists are more efficacious at attenuating pain-depressed behaviours. What does this study add? NMDA receptor antagonists produce dissociable effects on pain-depressed behaviour. Provides evidence that pain-depressed behaviours should be considered and evaluated when determining the antinociceptive effects of NMDA receptor antagonists. PMID:26914635

A study protocol for a single-blind, randomized controlled trial of adjunctive transcranial direct current stimulation (tDCS) for chronic pain among patients receiving specialized, inpatient multimodal pain management.

PubMed

Janice Jimenez-Torres, G; Weinstein, Benjamin L; Walker, Cory R; Christopher Fowler, J; Ashford, Philippa; Borckardt, Jeffrey J; Madan, Alok

2017-03-01

Available treatments for chronic pain (CP) are modestly effective or associated with iatrogenic harm. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that may be an effective, adjunctive treatment to non-opioid therapies. In this randomized control trial (RCT), we compare adjunctive active versus sham tDCS among patients in a multimodal inpatient pain management program. The primary objectives of the RCT are to improve pain tolerance and subjective pain experience. Patients admitted to the Pain Management Program at The Menninger Clinic in Houston, Texas are eligible for this trial. Eighty-four participants will be randomized (1:1) into a single-blind, 2×12 (group×time) controlled trial. A battery-powered direct and constant current stimulator (Soterix Medical Inc. 2014) delivers anodal stimulation over the left dorsolateral prefrontal cortex (DLPFC) and cathodal stimulation over the right DLPFC. Active tDCS is applied by supplying a 2mA current for 20min/session over 10 sessions. Participants complete self-report and performance-based assessments on a weekly basis just prior to brain stimulation. Self-report assessments are collected via Chronic Pain Tracker version 3.6, an iPad interfaced application. The performance-based pain tolerance task is completed through the cold presser task. Interventions with cross-symptomatic therapeutic potential are absolutely essential in the context of CP, in which psychiatric comorbidity is the norm. Modalities that can be used in tandem with evidence-based, non-opioid therapies have the potential to have a synergistic effect, resulting in increased effectiveness of what have been modestly effective treatments to date. Copyright © 2017 Elsevier Inc. All rights reserved.

Repetitive transcranial magnetic stimulation and transcranial direct-current stimulation in neuropathic pain due to radiculopathy: a randomized sham-controlled comparative study.

PubMed

Attal, Nadine; Ayache, Samar S; Ciampi De Andrade, Daniel; Mhalla, Alaa; Baudic, Sophie; Jazat, Frédérique; Ahdab, Rechdi; Neves, Danusa O; Sorel, Marc; Lefaucheur, Jean-Pascal; Bouhassira, Didier

2016-06-01

No study has directly compared the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) in neuropathic pain (NP). In this 2-centre randomised double-blind sham-controlled study, we compared the efficacy of 10-Hz rTMS and anodal 2-mA tDCS of the motor cortex and sham stimulation contralateral to the painful area (3 daily sessions) in patients with NP due to lumbosacral radiculopathy. Average pain intensity (primary outcome) was evaluated after each session and 5 days later. Secondary outcomes included neuropathic symptoms and thermal pain thresholds for the upper limbs. We used an innovative design that minimised bias by randomly assigning patients to 1 of 2 groups: active rTMS and tDCS or sham rTMS and tDCS. For each treatment group (active or sham), the order of the sessions was again randomised according to a crossover design. In total, 51 patients were screened and 35 (51% women) were randomized. Active rTMS was superior to tDCS and sham in pain intensity (F = 2.89 and P = 0.023). Transcranial direct-current stimulation was not superior to sham, but its analgesic effects were correlated to that of rTMS (P = 0.046), suggesting common mechanisms of action. Repetitive transcranial magnetic stimulation lowered cold pain thresholds (P = 0.04) and its effect on cold pain was correlated with its analgesic efficacy (P = 0.006). However, rTMS had no impact on individual neuropathic symptoms. Thus, rTMS is more effective than tDCS and sham in patients with NP due to lumbosacral radiculopathy and may modulate the sensory and affective dimensions of pain.

Acoustic Events and “Optophonic” Cochlear Responses Induced by Pulsed Near-Infrared LASER

PubMed Central

Maier, Hannes; Richter, Claus-Peter; Kral, Andrej

2012-01-01

Optical stimulation of neural tissue within the cochlea was described as a possible alternative to electrical stimulation. Most optical stimulation was performed with pulsed lasers operating with near-infrared (NIR) light and in thermal confinement. Under these conditions, the coexistence of laser-induced optoacoustic stimulation of the cochlea (“optophony”) has not been analyzed yet. This study demonstrates that pulsed 1850-nm laser light used for neural stimulation also results in sound pressure levels up to 62 dB peak-to-peak equivalent sound pressure level (SPL) in air. The sound field was confined to a small volume along the laser beam. In dry nitrogen, laser-induced acoustic events disappeared. Hydrophone measurements demonstrated pressure waves for laser fibers immersed in water. In hearing rats, laser-evoked signals were recorded from the cochlea without targeting neural tissue. The signals showed a two-domain response differing in amplitude and latency functions, as well as sensitivity to white-noise masking. The first component had characteristics of a cochlear microphonic potential, and the second component was characteristic for a compound action potential. The present data demonstrate that laser-evoked acoustic events can stimulate a hearing cochlea. Whenever optical stimulation is used, care must be taken to distinguish between such “optophony” and the true optoneural response. PMID:21278011

Evidence-based guidelines for the chiropractic treatment of adults with neck pain.

PubMed

Bryans, Roland; Decina, Philip; Descarreaux, Martin; Duranleau, Mireille; Marcoux, Henri; Potter, Brock; Ruegg, Richard P; Shaw, Lynn; Watkin, Robert; White, Eleanor

2014-01-01

The purpose of this study was to develop evidence-based treatment recommendations for the treatment of nonspecific (mechanical) neck pain in adults. Systematic literature searches of controlled clinical trials published through December 2011 relevant to chiropractic practice were conducted using the databases MEDLINE, EMBASE, EMCARE, Index to Chiropractic Literature, and the Cochrane Library. The number, quality, and consistency of findings were considered to assign an overall strength of evidence (strong, moderate, weak, or conflicting) and to formulate treatment recommendations. Forty-one randomized controlled trials meeting the inclusion criteria and scoring a low risk of bias were used to develop 11 treatment recommendations. Strong recommendations were made for the treatment of chronic neck pain with manipulation, manual therapy, and exercise in combination with other modalities. Strong recommendations were also made for the treatment of chronic neck pain with stretching, strengthening, and endurance exercises alone. Moderate recommendations were made for the treatment of acute neck pain with manipulation and mobilization in combination with other modalities. Moderate recommendations were made for the treatment of chronic neck pain with mobilization as well as massage in combination with other therapies. A weak recommendation was made for the treatment of acute neck pain with exercise alone and the treatment of chronic neck pain with manipulation alone. Thoracic manipulation and trigger point therapy could not be recommended for the treatment of acute neck pain. Transcutaneous nerve stimulation, thoracic manipulation, laser, and traction could not be recommended for the treatment of chronic neck pain. Interventions commonly used in chiropractic care improve outcomes for the treatment of acute and chronic neck pain. Increased benefit has been shown in several instances where a multimodal approach to neck pain has been used. © 2014. Published by National University of Health Sciences All rights reserved.

The efficacy of low-level laser treatment in reducing pain and swelling after endodontic surgery: a systematic review

NASA Astrophysics Data System (ADS)

Moshari, Amirabbas; Vatanpour, Mehdi; Zakershahrak, Mehrsa

2016-03-01

Introduction: LLLT in oral cavity believed to reduce pain after endodontic surgery and wisdom tooth removal, to accelerate wound healing and to have an anti-inflammatory and regenerative effect. The aim of this systematic review therefore was to assess the proof available for the efficacy of low-level laser treatment in reducing pain and swelling after endodontic surgery. Methods: The PubMed service of the U.S. National Library of Medicine was searched with applicable search strategies. No language restriction was applied. The last electronic search was accomplished on August 31, 2015. All randomized clinical trials on the efficiency of low-level laser treatment in reducing pain and swelling after endodontic surgery was considered for the Meta-analysis. Quality consideration of the included randomized clinical trials was appraised according to CONSORT guidelines. Results: Only two randomized clinical trials were attained. These studies clarified that laser treatment could reduce pain and swelling, but the results were not significant. Conclusions: Low-level laser therapy can be advantageous for the reduction of postoperative pain but there is no strong confirmation for its efficiency. Its clinical utility and applicability relating to endodontic surgery, Along with the optimal energy dosage and the number of laser treatments needed after surgery, still, demand further research and experiment.

Reduction of pain thresholds in fibromyalgia after very low-intensity magnetic stimulation: a double-blinded, randomized placebo-controlled clinical trial.

PubMed

Maestú, Ceferino; Blanco, Manuel; Nevado, Angel; Romero, Julia; Rodríguez-Rubio, Patricia; Galindo, Javier; Bautista Lorite, Juan; de las Morenas, Francisco; Fernández-Argüelles, Pedro

2013-01-01

Exposure to electromagnetic fields has been reported to have analgesic and antinociceptive effects in several organisms. To test the effect of very low-intensity transcranial magnetic stimulation on symptoms associated with fibromyalgia syndrome. A double-blinded, placebo-controlled clinical trial was performed in the Sagrado Corazón Hospital, Seville, Spain. Female fibromyalgia patients (22 to 50 years of age) were randomly assigned to either a stimulation group or a sham group. The stimulation group (n=28) was stimulated using 8 Hz pulsed magnetic fields of very low intensity, while the sham group (n=26) underwent the same protocol without stimulation. Pressure pain thresholds before and after stimulation were determined using an algometer during the eight consecutive weekly sessions of the trial. In addition, blood serotonin levels were measured and patients completed questionnaires to monitor symptom evolution. A repeated-measures ANOVA indicated statistically significant improvement in the stimulation group compared with the control group with respect to somatosensory pain thresholds, ability to perform daily activities, perceived chronic pain and sleep quality. While improvement in pain thresholds was apparent after the first stimulation session, improvement in the other three measures occurred after the sixth week. No significant between-group differences were observed in scores of depression, fatigue, severity of headaches or serotonin levels. No adverse side effects were reported in any of the patients. Very low-intensity magnetic stimulation may represent a safe and effective treatment for chronic pain and other symptoms associated with fibromyalgia.

Reduction of pain thresholds in fibromyalgia after very low-intensity magnetic stimulation: A double-blinded, randomized placebo-controlled clinical trial

PubMed Central

Maestú, Ceferino; Blanco, Manuel; Nevado, Angel; Romero, Julia; Rodríguez-Rubio, Patricia; Galindo, Javier; Lorite, Juan Bautista; de las Morenas, Francisco; Fernández-Argüelles, Pedro

2013-01-01

BACKGROUND: Exposure to electromagnetic fields has been reported to have analgesic and antinociceptive effects in several organisms. OBJECTIVE: To test the effect of very low-intensity transcranial magnetic stimulation on symptoms associated with fibromyalgia syndrome. METHODS: A double-blinded, placebo-controlled clinical trial was performed in the Sagrado Corazón Hospital, Seville, Spain. Female fibromyalgia patients (22 to 50 years of age) were randomly assigned to either a stimulation group or a sham group. The stimulation group (n=28) was stimulated using 8 Hz pulsed magnetic fields of very low intensity, while the sham group (n=26) underwent the same protocol without stimulation. Pressure pain thresholds before and after stimulation were determined using an algometer during the eight consecutive weekly sessions of the trial. In addition, blood serotonin levels were measured and patients completed questionnaires to monitor symptom evolution. RESULTS: A repeated-measures ANOVA indicated statistically significant improvement in the stimulation group compared with the control group with respect to somatosensory pain thresholds, ability to perform daily activities, perceived chronic pain and sleep quality. While improvement in pain thresholds was apparent after the first stimulation session, improvement in the other three measures occurred after the sixth week. No significant between-group differences were observed in scores of depression, fatigue, severity of headaches or serotonin levels. No adverse side effects were reported in any of the patients. CONCLUSIONS: Very low-intensity magnetic stimulation may represent a safe and effective treatment for chronic pain and other symptoms associated with fibromyalgia. PMID:24308025

Continuous-wave infrared optical nerve stimulation for potential diagnostic applications

NASA Astrophysics Data System (ADS)

Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2010-09-01

Optical nerve stimulation using infrared laser radiation has recently been developed as a potential alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuous-wave (cw) infrared laser radiation for potential diagnostic applications. A thulium fiber laser (λ=1870 nm) is used for noncontact optical stimulation of the rat prostate cavernous nerves in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, is achieved with the laser operating in either cw mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation is observed to be primarily dependent on a threshold nerve temperature (42 to 45 °C), rather than an incident fluence, as previously reported. cw optical nerve stimulation provides a significantly faster ICP response time using a lower power (and also less expensive) laser than pulsed stimulation. cw optical nerve stimulation may therefore represent an alternative mode of stimulation for intraoperative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

Effectiveness of transcranial direct current stimulation preceding cognitive behavioural management for chronic low back pain: sham controlled double blinded randomised controlled trial.

PubMed

Luedtke, Kerstin; Rushton, Alison; Wright, Christine; Jürgens, Tim; Polzer, Astrid; Mueller, Gerd; May, Arne

2015-04-16

To evaluate the effectiveness of transcranial direct current stimulation alone and in combination with cognitive behavioural management in patients with non-specific chronic low back pain. Double blind parallel group randomised controlled trial with six months' follow-up conducted May 2011-March 2013. Participants, physiotherapists, assessors, and analyses were blinded to group allocation. Interdisciplinary chronic pain centre. 135 participants with non-specific chronic low back pain >12 weeks were recruited from 225 patients assessed for eligibility. Participants were randomised to receive anodal (20 minutes to motor cortex at 2 mA) or sham transcranial direct current stimulation (identical electrode position, stimulator switched off after 30 seconds) for five consecutive days immediately before cognitive behavioural management (four week multidisciplinary programme of 80 hours). Two primary outcome measures of pain intensity (0-100 visual analogue scale) and disability (Oswestry disability index) were evaluated at two primary endpoints after stimulation and after cognitive behavioural management. Analyses of covariance with baseline values (pain or disability) as covariates showed that transcranial direct current stimulation was ineffective for the reduction of pain (difference between groups on visual analogue scale 1 mm (99% confidence interval -8.69 mm to 6.3 mm; P=0.68)) and disability (difference between groups 1 point (-1.73 to 1.98; P=0.86)) and did not influence the outcome of cognitive behavioural management (difference between group 3 mm (-10.32 mm to 6.73 mm); P=0.58; difference between groups on Oswestry disability index 0 point (-2.45 to 2.62); P=0.92). The stimulation was well tolerated with minimal transitory side effects. This results of this trial on the effectiveness of transcranial direct current stimulation for the reduction of pain and disability do not support its clinical use for managing non-specific chronic low back pain.Trial registration Current controlled trials ISRCTN89874874. © Luedtke et al 2015.

Effect of low-level laser therapy on pain levels in patients with temporomandibular disorders: a systematic review

PubMed Central

MAIA, Mila Leite de Moraes; BONJARDIM, Leonardo Rigoldi; QUINTANS, Jullyana de Souza Siqueira; RIBEIRO, Maria Amália Gonzaga; MAIA, Luiz Guilherme Martins; CONTI, Paulo César Rodrigues

2012-01-01

Temporomandibular disorders (TMD) are characterized by the presence of temporomandibular joint (TMJ) and/or masticatory muscle pain and dysfunction. Low-level laser is presented as an adjuvant therapeutic modality for the treatment of TMD, especially when the presence of inflammatory pain is suspected. Objective To systematically review studies that investigated the effect of low level laser therapy (LLLT) on the pain levels in individuals with TMD. Material and Methods The databases Scopus, embase, ebsco and PubMed were reviewed from January/2003 to October/2010 with the following keywords: laser therapy, low-level laser therapy, temporomandibular joint disorders, temporomandibular joint dysfunction syndrome, temporomandibular joint, temporomandibular, facial pain and arthralgia, with the inclusion criteria for intervention studies in humans. exclusion criteria adopted were intervention studies in animals, studies that were not written in english, Spanish or Portuguese, theses, monographs, and abstracts presented in scientific events. Results After a careful review, 14 studies fit the criteria for inclusion, of which, 12 used a placebo group. As for the protocol for laser application, the energy density used ranged from 0.9 to 105 J/cm2, while the power density ranged from 9.8 to 500 mW. The number of sessions varied from 1 to 20 and the frequency of applications ranged from daily for 10 days to 1 time per week for 4 weeks. A reduction in pain levels was reported in 13 studies, with 9 of these occurring only in the experimental group, and 4 studies reporting pain relief for both the experimental group and for the placebo. Conclusion Most papers showed that LLLT seemed to be effective in reducing pain from TMD. However, the heterogeneity of the standardization regarding the parameters of laser calls for caution in interpretation of these results. Thus, it is necessary to conduct further research in order to obtain a consensus regarding the best application protocol for pain relief in patients with TMD. PMID:23329239

Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain

PubMed Central

Wu, Lien-Chen; Weng, Pei-Wei; Chen, Chia-Hsien; Huang, Yi-You; Tsuang, Yang-Hwei; Chiang, Chang-Jung

2018-01-01

Background and Objectives This study is a meta-analysis of randomized controlled trials comparing the efficacy of transcutaneous electrical nerve stimulation (TENS) to a control and to other nerve stimulation therapies (NSTs) for the treatment of chronic back pain. Methods Citations were identified in MEDLINE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov through June 2014 using the following keywords: nerve stimulation therapy, transcutaneous electrical nerve stimulation, back pain, chronic pain. Control treatments included sham, placebo, or medication only. Other NSTs included electroacupuncture, percutaneous electrical nerve stimulation, and percutaneous neuromodulation therapy. Results Twelve randomized controlled trials including 700 patients were included in the analysis. The efficacy of TENS was similar to that of control treatment for providing pain relief (standardized difference in means [SDM] = −0.20; 95% confidence interval [CI], −0.58 to 0.18; P = 0.293). Other types of NSTs were more effective than TENS in providing pain relief (SDM = 0.86; 95% CI, 0.15–1.57; P = 0.017). Transcutaneous electrical nerve stimulation was more effective than control treatment in improving functional disability only in patients with follow-up of less than 6 weeks (SDM = −1.24; 95% CI, −1.83 to −0.65; P < 0.001). There was no difference in functional disability outcomes between TENS and other NSTs. Conclusions These results suggest that TENS does not improve symptoms of lower back pain, but may offer short-term improvement of functional disability. PMID:29394211

Different mechanisms for the short-term effects of real versus sham transcutaneous electrical nerve stimulation (TENS) in patients with chronic pain: a pilot study.

PubMed

Oosterhof, Jan; Wilder-Smith, Oliver H; Oostendorp, Rob A; Crul, Ben J

2012-01-01

Transcutaneous electrical nerve stimulation (TENS) has existed since the early 1970s. However, randomized placebo controlled studies show inconclusive results in the treatment of chronic pain. These results could be explained by assuming that TENS elicits a placebo response. However, in animal research TENS has been found to decrease hyperalgesia, which contradicts this assumption. The aim of this study is to use quantitative sensory testing to explore changes in pain processing during sham versus real TENS in patients with chronic pain. Patients with chronic pain (N = 20) were randomly allocated to real TENS or sham TENS application. Electrical pain thresholds (EPTs) were determined inside and outside the segment stimulated, before and after the first 20 minutes of the intervention, and after a period of 10 days of daily real/sham TENS application. Pain relief did not differ significantly for real versus sham TENS. However, by comparing time courses of EPTs, it was found that EPT values outside the segment of stimulation increased for sham TENS, whereas for real TENS these values decreased. There were, however, no differences for EPT measurements inside the segment stimulated. These results illustrate the importance of including mechanism-reflecting parameters in addition to symptoms when conducting pain research.

The effectiveness of low laser therapy in subacromial impingement syndrome: a randomized placebo controlled double‐blind prospective study

PubMed Central

Dogan, Sebnem Koldas; AY, Saime; Evcik, Deniz

2010-01-01

OBJECTIVES: Conflicting results were reported about the effectiveness of Low level laser therapy on musculoskeletal disorders. The aim of this study was to investigate the effectiveness of 850‐nm gallium arsenide aluminum (Ga‐As‐Al) laser therapy on pain, range of motion and disability in subacromial impingement syndrome. METHODS: A total of 52 patients (33 females and 19 males with a mean age of 53.59±11.34 years) with subacromial impingement syndrome were included. The patients were randomly assigned into two groups. Group I (n = 30, laser group) received laser therapy (5 joule/cm2 at each point over maximum 5‐6 painful points for 1 minute). Group II (n = 22, placebo laser group) received placebo laser therapy. Initially cold pack (10 minutes) was applied to all of the patients. Also patients were given an exercise program including range of motion, stretching and progressive resistive exercises. The therapy program was applied 5 times a week for 14 sessions. Pain severity was assessed by using visual analogue scale. Range of motion was measured by goniometer. Disability was evaluated by using Shoulder Pain and Disability Index. RESULTS: In group I, statistically significant improvements in pain severity, range of motion except internal and external rotation and SPADI scores were observed compared to baseline scores after the therapy (p<0.05). In Group II, all parameters except range of motion of external rotation were improved (p<0.05). However, no significant differences were recorded between the groups (p>0.05). CONCLUSIONS: The Low level laser therapy seems to have no superiority over placebo laser therapy in reducing pain severity, range of motion and functional disability. PMID:21120304

[Pain as a stimulator of protective and curative processes (the theory of pain)].

PubMed

Uglov, F G; Kopylov, V A

1985-06-01

The work deals with the theoretical approach to problem of pain. The mechanism of the appearance of pain is considered as lack of correspondence between functional capacity of the nervous system and the presented load. The function of pain as reparator and stimulator of defensive forces of the organism in pathological processes is disclosed. The possible employment of pain as a curative factor in practical medicine is discussed.

Technical Note: Treatment of Sacroiliac Joint Pain with Peripheral Nerve Stimulation.

PubMed

Guentchev, Marin; Preuss, Christian; Rink, Rainer; Peter, Levente; Wocker, Ernst-Ludwig; Tuettenberg, Jochen

2015-07-01

Sacroiliac joint (SIJ) pain affects older adults with a prevalence of up to 20% among patients with chronic low back pain. While pain medication, joint blocks and denervation procedures achieve pain relief in most patients, some cases fail to improve. Our goal was to determine the effectiveness of SIJ peripheral nerve stimulation in patients with severe conservative therapy-refractory SIJ pain. Here we present 12 patients with severe conservative therapy-refractory pain receiving an SIJ peripheral nerve stimulation. Patient satisfaction, pain, and quality of life were evaluated by means of the International Patient Satisfaction Index (IPSI), visual analog scale (VAS), and Oswestry Disability Index 2.0 (ODI) using standard questionnaires. For stimulation we placed an eight-pole peripheral nerve electrode parallel to the SIJ. Two weeks postoperatively, our patients reported an average ODI reduction from 57% to 32% and VAS from 9 to 2.1. IPSI was 1.1. After six months, the therapy was rated as effective in seven out of eight patients reporting at that period. The average ODI was low at 34% (p = 0.0006), while the VAS index rose to 3.8 (p < 0.0001) and IPSI to 1.9. Twelve months after stimulation, six out of seven patients considered their treatment a success with an average ODI of 21% (p < 0.0005), VAS 1.7 (p < 0.0001), and IPSI 1.3. We conclude that SIJ stimulation is a promising therapeutic strategy in the treatment of intractable SIJ pain. Further studies are required to determine the precise target group and long-term effect of this novel treatment method. © 2014 International Neuromodulation Society.

Right secondary somatosensory cortex-a promising novel target for the treatment of drug-resistant neuropathic orofacial pain with repetitive transcranial magnetic stimulation.

PubMed

Lindholm, Pauliina; Lamusuo, Salla; Taiminen, Tero; Pesonen, Ullamari; Lahti, Ari; Virtanen, Arja; Forssell, Heli; Hietala, Jarmo; Hagelberg, Nora; Pertovaara, Antti; Parkkola, Riitta; Jääskeläinen, Satu

2015-07-01

High-frequency repetitive transcranial magnetic stimulation (rTMS) of the motor cortex has analgesic effect; however, the efficacy of other cortical targets and the mode of action remain unclear. We examined the effects of rTMS in neuropathic orofacial pain, and compared 2 cortical targets against placebo. Furthermore, as dopaminergic mechanisms modulate pain responses, we assessed the influence of the functional DRD2 gene polymorphism (957C>T) and the catechol-O-methyltransferase (COMT) Val158Met polymorphism on the analgesic effect of rTMS. Sixteen patients with chronic drug-resistant neuropathic orofacial pain participated in this randomized, placebo-controlled, crossover study. Navigated high-frequency rTMS was given to the sensorimotor (S1/M1) and the right secondary somatosensory (S2) cortices. All subjects were genotyped for the DRD2 957C>T and COMT Val158Met polymorphisms. Pain, mood, and quality of life were monitored throughout the study. The numerical rating scale pain scores were significantly lower after the S2 stimulation than after the S1/M1 (P = 0.0071) or the sham (P = 0.0187) stimulations. The Brief Pain Inventory scores were also lower 3 to 5 days after the S2 stimulation than those at pretreatment baseline (P = 0.0127 for the intensity of pain and P = 0.0074 for the interference of pain) or after the S1/M1 (P = 0.001 and P = 0.0001) and sham (P = 0.0491 and P = 0.0359) stimulations. No correlations were found between the genetic polymorphisms and the analgesic effect in the present small clinical sample. The right S2 cortex is a promising new target for the treatment of neuropathic orofacial pain with high-frequency rTMS.

A randomised controlled trial of coblation, diode laser and cold dissection in paediatric tonsillectomy.

PubMed

Elbadawey, M R; Hegazy, H M; Eltahan, A E; Powell, J

2015-11-01

This study aimed to compare the efficacy of diode laser, coblation and cold dissection tonsillectomy in paediatric patients. A total of 120 patients aged 10-15 years with recurrent tonsillitis were recruited. Participants were prospectively randomised to diode laser, coblation or cold dissection tonsillectomy. Operative time and blood loss were recorded. Pain was recorded on a Wong-Baker FACES(®) pain scale. The operative time (10 ± 0.99 minutes), blood loss (20 ± 0.85 ml) and pain were significantly lower with coblation tonsillectomy than with cold dissection tonsillectomy (20 ± 1.0 minutes and 30 ± 1.0 ml; p = 0.0001) and diode laser tonsillectomy (15 ± 0.83 minutes and 25 ± 0.83 ml; p = 0.0001). Diode laser tonsillectomy had a shorter operative time (p = 0.0001) and less blood loss (p = 0.001) compared with cold dissection tonsillectomy. However, at post-operative day seven, the diode laser tonsillectomy group had significantly higher pain scores compared with the cold dissection (p = 0.042) and coblation (p = 0.04) tonsillectomy groups. Both coblation and diode laser tonsillectomy are associated with significantly reduced blood loss and shorter operative times compared with cold dissection tonsillectomy. However, we advocate coblation tonsillectomy because of the lower post-operative pain scores compared with diode laser and cold dissection tonsillectomy.

Investigation of laser induced parametric interactions in optical waveguides and fibers

NASA Technical Reports Server (NTRS)

Yu, C.

1978-01-01

Experimental and theoretical aspects of the laser pump depletion characteristics in an optical fiber due to stimulated Raman scattering, and stimulated Brillouin scattering were studied. A review is presented of research in fiber transmission accompanied by stimulated scattering. Results of experimental work with tunable dye lasers and argon lasers are presented. The spectral profiles of the laser pump and its transmitted light through the fiber are given.

Stimulation of the peripheral nervous system for pain control.

PubMed

Long, D M

1983-01-01

Transcutaneous stimulation is a proven effective way to relieve pain. Its optimal use requires an accurate patient diagnosis. Treatment of pain as a symptom only is likely to fail. There must be a careful psychosocial evaluation, for the majority of patients who come to the doctor complaining of pain have major psychological, social, or behavioral factors that are most important in the genesis of the complaint. Drug abuse must be corrected. Related symptoms, such as anxiety and depression, must be treated. Then, a thorough trail of transcutaneous stimulation is mandatory. A desultory use will undoubtedly lead to failure. This trial must begin with patient education by experienced personnel. Then the electrodes must be properly applied, and there must be a regular follow-up of stimulation to be certain the patient is utilizing it correctly. The patient must be supported through an adequate trial which should extend over 2-4 weeks before purchase of the device is contemplated. Furthermore, all related nursing and physician personnel must be educated in the proper use of the technique. The uninformed professional who denigrates the therapy is a very effective deterrent to appropriate use. In this situation, transcutaneous electrical stimulation will be of great value in the treatment of acute musculoskeletal injury and acute postoperative pain. It will be effective in the treatment of peripheral nerve injury pain, chronic musculoskeletal abnormalities, chronic pain in the patient who has undergone multiple operations upon the low back and neck, visceral pain, some of the reflex sympathetic dystrophies, and postherpetic neuralgia. Stimulation will not help a complaint which is psychosomatic in origin. It will not influence drug addiction. It is not likely to be useful in any situation where secondary gain is important. The metabolic neuropathies, pain of spinal cord injury, and pain from cerebrovascular accident will not respond frequently enough to warrant more than hopeful trials. The technique is inexpensive, places the patient in control of his own pain, and has no known serious side effects. Its widespread application awaits the development of reasonable systems to provide this service to physicians and patients. Stimulation-induced analgesia deserves a place in the armamentarium of every physician dealing with the complaint of pain.

The Use Of Laser Irradiation To Stimulate Adipose Derived Stem Cell Proliferation And Differentiation For Use In Autologous Grafts

NASA Astrophysics Data System (ADS)

Abrahamse, Heidi

2009-09-01

Stem cells are characterized by the qualities of self-renewal, long term viability, and the ability to differentiate into various cell types. Historically, stem cells have been isolated from the inner cell mass of blastocysts and harvesting these cells resulted in the death of the embryo leading to religious, political and ethical issues. The identification and subsequent isolation of adult stem cells from bone marrow stroma have been welcomed as an alternate source for stem cells. The clinical use of Mesenchymal Stem Cells (MSCs) presented problems such as limited cell number, pain and morbidity upon isolation. Adipose tissue is derived from the mesenchyme, is easily isolated, a reliable source of stem cells and able to differentiate into different cell types including smooth muscle. Over the past few years, the identification and characterization of stem cells has led the potential use of these cells as a promising alternative to cell replacement therapy. Smooth muscle is a major component of human tissues and is essential for the normal functioning of many different organs. Low intensity laser irradiation has been shown to increase viability, protein expression and migration of stem cells in vitro, and to stimulate proliferation of various types of stem cells. In addition, the use of laser irradiation to stimulate differentiation in the absence of growth factors has also been demonstrated in normal human neural progenitor cells (NHNPCs) in vitro where NHNPCs are not only capable of being sustained by light in the absence of growth factors, but that they are also able to differentiate normally as assessed by neurite formation. Our work has focused on the ability of laser irradiation to proliferate adipose derived stem cells (ADSCs), maintain ADSC character and increase the rate and maintenance of differentiation of ADSCs into smooth muscle and skin fibroblast cells. Current studies are also investigating the effect of different irradiation wavelengths and fluences on ADSC viability and proliferation. This paper reviews the development of MSCs as potential therapeutic interventions such as autologous grafts as well as the contribution of low intensity laser irradiation on the maintenance of these cells.

Transcranial Direct Current Stimulation (tDCS) Targeting Left Dorsolateral Prefrontal Cortex Modulates Task-Induced Acute Pain in Healthy Volunteers.

PubMed

Mariano, Timothy Y; Van't Wout, Mascha; Garnaat, Sarah L; Rasmussen, Steven A; Greenberg, Benjamin D

2016-04-01

Current chronic pain treatments target nociception rather than affective "suffering" and its associated functional and psychiatric comorbidities. The left dorsolateral prefrontal cortex (DLPFC) has been implicated in affective, cognitive, and attentional aspects of pain and is a primary target of neuromodulation for affective disorders. Transcranial direct current stimulation (tDCS) can non-invasively modulate cortical activity. The present study tests whether anodal tDCS targeting the left DLPFC will increase tolerability of acute painful stimuli vs cathodal tDCS. Forty tDCS-naive healthy volunteers received anodal and cathodal stimulation targeting the left DLPFC in two randomized and counterbalanced sessions. During stimulation, each participant performed cold pressor (CP) and breath holding (BH) tasks. We measured pain intensity with the Defense and Veterans Pain Rating Scale (DVPRS) before and after each task. Mixed ANOVA revealed no main effect of stimulation polarity for mean CP threshold, tolerance, or endurance, or mean BH time (allP > 0.27). However, DVPRS rise associated with CP was significantly smaller with anodal vs cathodal tDCS (P = 0.024). We further observed a significant tDCS polarity × stimulation order interaction (P = 0.042) on CP threshold, suggesting task sensitization. Although our results do not suggest that polarity of tDCS targeting the left DLPFC differentially modulates the tolerability of CP- and BH-related pain distress in healthy volunteers, there was a significant effect on DVPRS pain ratings. This contrasts with our previous findings that tDCS targeting the left dorsal anterior cingulate cortex showed a trend toward higher mean CP tolerance with cathodal vs anodal stimulation. The present results may suggest tDCS-related effects on nociception or DLPFC-mediated attention, or preferential modulation of the affective valence of pain as captured by the DVPRS. Sham-controlled clinical studies are needed. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Low-level laser therapy and interferential current in patients with knee osteoarthritis: a randomized controlled trial protocol.

PubMed

Alqualo-Costa, Renata; Thomé, Gustavo R; Perracini, Mônica R; Liebano, Richard E

2018-05-03

The aim of this study is to investigate the effects of low-level laser therapy and interferential current (IFC) on pain intensity, central sensitization, muscle strength and functional capacity in patients with knee osteoarthritis. Participants will be patients aged between 50 and 80 years, with knee osteoarthritis, pain intensity ranging from 3 to 8 points (0-10 scale), Lequesne Algofunctional Index ranging from 5 to 15 points, and Kellgren & Lawrence grade ≥2. A total of 168 patients will be randomly allocated into four groups as follows: active IFC + laser sham (G1), IFC sham + active laser (G2), active IFC + laser (G3) and IFC + laser sham (G4). Evaluators will be blinded to group allocation. Primary outcomes will be pain at rest and during movement measured with the visual analog pain scale. Clinical Trials Registry (NCT02898025. Registered on 20 April 2016).

Single-Spot Yellow Laser Versus Conventional Green Laser on Panretinal Photocoagulation: Patient Pain Scores and Preferences.

PubMed

González-Saldivar, Gerardo; Rojas-Juárez, Sergio; Espinosa-Soto, Itzel; Sánchez-Ramos, Jorge; Jaurieta-Hinojosa, Noel; Ramírez-Estudillo, Abel

2017-11-01

Panretinal photocoagulation (PRP) is the mainstay therapy for proliferative diabetic retinopathy. Pain during and after its application is a complication that affects patients' therapeutic adherence. This study aimed to compare pain perception and patient preference for the 577-nm yellow laser (YL-577) (LIGHTL as 577; LIGHTMED, San Clemente, CA) and the conventional 532-nm green laser (GL-532) (Purepoint Laser; Alcon, Fort Worth, TX) with PRP. A total of 92 patient eyes with proliferative diabetic retinopathy treated with PRP were randomly assigned to receive both GL-532 and YL-577 (184 eyes) - one on each eye, with the order of application randomized, as well. Afterward, verbal rapid answer and visual analogue scale (VAS) scores for pain perception and patient preference were evaluated. VAS score was 7 ± 2 for the GL-532 group compared to 5 ± 3 in the YL-577 group (P = .001). Overall, 75% of the patients preferred YL-577 therapy if they were to receive a second PRP session. The use of YL-577 as an alternative approach for PRP reduces pain perception and is preferred by patients. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:902-905.]. Copyright 2017, SLACK Incorporated.

Electrical or repetitive transcranial magnetic stimulation of primary motor cortex for intractable neuropathic pain.

PubMed

Saitoh, Youichi; Maruo, Tomoyuki; Yokoe, Masaru; Matsuzaki, Taiga; Sekino, Masaki

2013-01-01

To assess the pain-relieving effects of motor cortex electrical stimulation (MCS) and the predictive factors retrospectively. Thirty-four patients with intractable neuropathic pain underwent MCS; 19 patients had cerebral lesions, and 15 had non-cerebral lesions. In selected 12 patients, test electrodes were implanted within the central sulcus and on the precentral gyrus. Twelve patients received both MCS and repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex. Pain reduction of >50% was observed in 12 of 32 (36%) patients with >12 months follow-ups (2 patients were excluded because of short follow-up). In 10 of the 12 patients who received test electrodes within the central sulcus and on the precentral gyrus, the optimal stimulation was MCS within the central sulcus. In 4 of these (40%) patients, positive effects were maintained at follow-ups. The pain reduction of rTMS significantly correlated with that of MCS during test stimulation. The test stimulation within the central sulcus was more effective than that of the precentral gyrus. In the selected patients, chronic stimulation within the central sulcus did not significantly improve long-term results. Repeated rTMS seems to be same effective as MCS.

Effects of smoke exposure and other lifestyle factors on pain response to electrical stimulation in women.

PubMed

Wee, J Y; Hopman, W M

2008-01-01

A relationship between smoking and development of pain syndromes has been suggested in the literature. The present study examined associations between smoke exposure and other related variables, and pain response to suprathreshold electrical stimulation. Subjects were prospectively recruited from a population referred to an electrodiagnostic clinic. Information about age, smoke exposure, caffeine and alcohol consumption was obtained, as well as documented objective signs of stress through physical assessment. One investigator applied two standardized 0.1 ms electrical stimulations (50 mA followed by 100 mA) to asymptomatic extremities at the beginning of each electrodiagnostic session, using consistent technique. Subjects used a visual analogue scale to indicate the level of pain felt after each stimulation. Two hundred fifteen women were included. Current smokers and those currently exposed to second-hand smoke had significantly higher pain ratings (P=0.003 for 50 mA, P=0.005 for 100 mA) than those not currently exposed to smoke. Time since exposure was negatively associated with pain ratings. Those with objective signs of stress reported higher levels of pain, which was significant for the 100 mA stimulation (P=0.046). Linear regression modelling indicated that current smoke exposure and alcohol use were associated with higher pain ratings at both 50 mA and 100 mA, while stress was associated with higher pain ratings and older age was associated with lower pain ratings at 100 mA only. Exposure to cigarette smoke is significantly related to higher reported levels of pain experienced in response to electrical stimulation in this study population. Exposure to smoke can add 10 points to the 100-point visual analogue scale compared with subjects without exposure, with alcohol use adding another eight points. Reported pain decreases as length of time since previous exposure to smoke increases.

Brain Stimulation in the Treatment of Chronic Neuropathic and Non-Cancerous Pain

PubMed Central

Plow, EB; Pascual-Leone, A; Machado, A

2012-01-01

Chronic neuropathic pain is one of the most prevalent and debilitating disorders. Conventional medical management, however, remains frustrating for both patients and clinicians owing to poor specificity of pharmacotherapy, delayed-onset of analgesia and extensive side-effects. Neuromodulation presents as a promising alternative, or at least an adjunct, as it is more specific in inducing analgesia without associated risks of pharmacotherapy. Here, we discuss common clinical and investigational methods of neuromodulation. Compared to clinical spinal cord stimulation (SCS), investigational techniques of cerebral neuromodulation, both invasive [deep brain stimulation (DBS) and motor cortical stimulation (MCS)] and noninvasive [repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS)], may be more advantageous. By adaptively targeting the multi-dimensional experience of pain, subtended by integrative pain circuitry in the brain, including somatosensory and thalamocortical, limbic and cognitive, cerebral methods may modulate the sensory-discriminative, affective-emotional and evaluative-cognitive spheres of the pain neuromatrix. Despite promise, the current state of results alludes to the possibility that cerebral neuromodulation has thus far not been effective in producing analgesia as intended in patients with chronic pain disorders. These techniques, thus, remain investigational and off-label. We discuss issues implicated in inadequate efficacy, variability of responsiveness and poor retention of benefit, while recommending design and conceptual refinements for future trials of cerebral neuromodulation in management of chronic neuropathic pain. PMID:22484179

Do pain-associated contexts increase pain sensitivity? An investigation using virtual reality.

PubMed

Harvie, Daniel S; Sterling, Michele; Smith, Ashley D

2018-04-30

Pain is not a linear result of nociception, but is dependent on multisensory inputs, psychological factors, and prior experience. Since nociceptive models appear insufficient to explain chronic pain, understanding non-nociceptive contributors is imperative. Several recent models propose that cues associatively linked to painful events might acquire the capacity to augment, or even cause, pain. This experiment aimed to determine whether contexts associated with pain, could modulate mechanical pain thresholds and pain intensity. Forty-eight healthy participants underwent a contextual conditioning procedure, where three neutral virtual reality contexts were paired with either unpredictable noxious stimulation, unpredictable vibrotactile stimulation, or no stimulation. Following the conditioning procedure, mechanical pain thresholds and pain evoked by a test stimulus were examined in each context. In the test phase, the effect of expectancy was equalised across conditions by informing participants when thresholds and painful stimuli would be presented. Contrary to our hypothesis, scenes that were associated with noxious stimulation did not increase mechanical sensitivity (p=0.08), or increase pain intensity (p=0.46). However, an interaction with sex highlighted the possibility that pain-associated contexts may alter pain sensitivity in females but not males (p=0.03). Overall, our data does not support the idea that pain-associated contexts can alter pain sensitivity in healthy asymptomatic individuals. That an effect was shown in females highlights the possibility that some subgroups may be susceptible to such an effect, although the magnitude of the effect may lack real-world significance. If pain-associated cues prove to have a relevant pain augmenting effect, in some subgroups, procedures aimed at extinguishing pain-related associations may have therapeutic potential.

C2 subcutaneous stimulation for failed back surgery syndrome: a case report.

PubMed

De Ridder, Dirk; Plazier, Mark; Menovsky, Tomas; Kamerling, Niels; Vanneste, Sven

2013-01-01

Failed back surgery syndrome (FBSS) is a term embracing a constellation of conditions that describes persistent or recurring low back pain, with or without sciatica following one or more spine surgeries. It has been shown in animals that electrical stimulation of the high cervical C2 area can suppress pain stimuli derived from the L5-S1 dermatome. It is unknown whether C2 electrical stimulation in humans can be used to treat pain derived from the L5-S1 area, and a case is reported in which subcutaneous C2 is applied to treat FBSS. A patient presents to the neuromodulation clinic because of FBSS (after three lumbar diskectomies) and noninvasive neuromodulation is performed consisting of transcutaneous electrical nerve stimulation (TENS) at C2. The C2 TENS stimulation is successful in improving pain. It induces paresthesias in the C2 dermatome above a certain amplitude threshold, but does not generate paresthesias in the pain area. However, the patient becomes allergic to the skin-applied TENS electrodes and therefore a new treatment strategy is discussed with the patient. A subcutaneous C2 electrode is inserted under local anesthesia, and attached to an external pulse generator. Three stimulation designs are tested: a classical tonic stimulation, consisting of 40 Hz stimulation, a placebo, and a burst stimulation, consisting of 40 Hz burst mode, with five spikes delivered at 500 Hz at 1000 μsec pulse width and 1000 μsec interspike interval. The patient's stimulation results demonstrate that burst mode is superior to placebo and tonic mode, and she receives a fully implanted C2 electrode connected to an internal pulse generator via an extension wire. The burst design is capable of both suppressing the least and worst pain effectively, and she has remained almost pain-free for over three years. © 2012 International Neuromodulation Society.

Effect of high-frequency repetitive transcranial magnetic stimulation on chronic central pain after mild traumatic brain injury: A pilot study.

PubMed

Choi, Gyu-Sik; Kwak, Sang Gyu; Lee, Han Do; Chang, Min Cheol

2018-02-28

Central pain can occur following traumatic brain injury, leading to poor functional recovery, limitation of activities of daily living, and decreased quality of life. The aim of this study was to determine whether high-frequency (10 Hz) repetitive transcranial magnetic stimulation, applied over the primary motor cortex of the affected hemisphere, can be used to manage chronic central pain after mild traumatic brain injury. Prospective randomized feasibility study. Twelve patients with mild traumatic brain injury and chronic central pain were randomly assigned to transcranial magnetic stimulation (high-frequency stimulation, 10 sessions) or sham groups. Diffuse tensor tractography revealed partially injured spinothalamocortical tracts in all recruited patients. A numerical rating scale (NRS) was used to evaluate pain intensity during pre-treatment and immediately after the 5th transcranial magnetic stimulation session (post1), 10th transcranial magnetic stimulation session (post2), and 1 (post3), 2 (post4), and 4 weeks (post 5) after finishing treatment. Physical and mental health status were evaluated using the Short Form 36 Health Survey (SF-36), including physical and mental component scores (PCS, MCS). The NRS score of the repetitive transcranial magnetic stimulation group was significantly lower than the sham group score at all clinical evaluation time-points during and after transcranial magnetic stimulation sessions. The transcranial magnetic stimulation group's SF-36 PCS score was significantly higher at post2, post3, post4, and post5 compared with the sham group. High-frequency transcranial magnetic stimulation may be used to manage chronic central pain and improve quality of life in patients with mild traumatic brain injury. However, this is a pilot study and further research is needed.

Relationships between the intensity and duration of Peltier heat stimulation and pain magnitude

PubMed Central

Vierck, Charles J.; Mauderli, Andre P.; Riley, Joseph L.

2013-01-01

Ramp-and-hold heat stimulation with a Peltier thermode is a standard procedure for quantitative sensory testing of human pain sensitivity. Because myelinated and unmyelinated nociceptive afferents respond preferentially to changing and steady temperatures, respectively, ramp-and-hold heat stimulation could assess processing of input from A-delta nociceptors early and C nociceptors late during prolonged thermal stimulation. In order to evaluate the progression from dynamic change to a steady temperature during prolonged Peltier stimulation, recordings of temperatures at the probe-skin interface were obtained. First, recordings of temperature during contact-and-hold stimulation (solenoid powered delivery of a preheated thermode to the skin) provided an evaluation of heat dissipation from the beginning of stimulation, uncontaminated by ramping. The heat sink effect lasted up to 8 sec. and accounted in part for substantial increases in pain intensity as a combined function of durations from 1–16 sec. and stimulus intensities from 43°C to 59°. Recordings during longer periods of stimulation showed that Peltier stimulation generated feedback oscillations in temperature for up to 75 sec that were tracked by subjects’ continuous ratings of pain. During 120 sec. trials, sensitization of pain was observed over 45 seconds after the oscillations subsided. In contrast, sensitization was not observed during 130.5 sec. of stimulation with alternately increasing and decreasing temperatures that maintained a target eVAS rating of 35. Thus, long duration stimulation can be utilized to evaluate sensitization, presumably of C nociception, when not disrupted by oscillations inherent to feedback control of Peltier stimulation. PMID:23423165

Relationships between the intensity and duration of Peltier heat stimulation and pain magnitude.

PubMed

Vierck, Charles J; Mauderli, Andre P; Riley, Joseph L

2013-03-01

Ramp-and-hold heat stimulation with a Peltier thermode is a standard procedure for quantitative sensory testing of human pain sensitivity. Because myelinated and unmyelinated nociceptive afferents respond preferentially to changing and steady temperatures, respectively, ramp-and-hold heat stimulation could assess processing of input from A-delta nociceptors early and C nociceptors late during prolonged thermal stimulation. In order to evaluate the progression from dynamic change to a steady temperature during prolonged Peltier stimulation, recordings of temperatures at the probe-skin interface were obtained. First, recordings of temperature during contact-and-hold stimulation (solenoid powered delivery of a preheated thermode to the skin) provided an evaluation of heat dissipation from the beginning of stimulation, uncontaminated by ramping. The heat-sink effect lasted up to 8 s and accounted in part for a slow increase in pain intensity for stimulus durations of 1-16 s and stimulus intensities of 43-59 °C. Recordings during longer periods of stimulation showed that feedback-controlled Peltier stimulation generated oscillations in temperature that were tracked for up to 75 s by subjects' continuous ratings of pain. During 120-s trials, sensitization of pain was observed over 45 s after the oscillations subsided. Thus, long-duration stimulation can be utilized to evaluate sensitization, presumably of C nociception, when not disrupted by oscillations in thermode temperature (e.g., those inherent to feedback control of Peltier stimulation). In contrast, sensitization was not observed during 130.5 s of stimulation with alternately increasing and decreasing temperatures that repeatedly activated A-delta nociceptors.

Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

PubMed

Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

2016-01-01

Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

Postural stability is altered by the stimulation of pain but not warm receptors in humans.

PubMed

Blouin, Jean-Sébastien; Corbeil, Philippe; Teasdale, Normand

2003-10-17

It is now recognized that large diameter myelinated afferents provide the primary source of lower limb proprioceptive information for maintaining an upright standing position. Small diameter afferents transmitting noxious stimuli, however, can also influence motor behaviors. Despite the possible influence of pain on motor behaviors, the effects of pain on the postural control system have not been well documented. Two cutaneous heat stimulations (experiment 1: non-noxious 40 degrees C; experiment 2: noxious 45 degrees C) were applied bilaterally on the calves of the subject with two thermal grills to stimulate A delta and C warm receptors and nociceptors in order to examine their effects on postural stability. The non-noxious stimulation induced a gentle sensation of warmth and the noxious stimulation induced a perception of heat pain (visual analogue scores of 0 and 46 mm, respectively). For both experiments, ten healthy young adults were tested with and without heat stimulations of the lower limbs while standing upright on a force platform with eyes open, eyes closed and eyes closed with tendon co-vibration of tibialis anterior and triceps surae muscles. The center of pressure displacements were analyzed to examine how both stimulations affected the regulation of quiet standing and if the effects were exacerbated when vision was removed or ankle proprioception perturbed. The stimulation of the warm receptors (40 degrees C) did not induce any postural deterioration. With pain (45 degrees C), subjects showed a significant increase in standard deviation, range and mean velocity of postural oscillations as well as standard deviation of the center of pressure velocity. The effects of heat pain were exacerbated when subjects had both their eyes closed and ankle tendons vibrated (increased standard deviation of the center of pressure velocity and mean velocity of the center of pressure). A non-noxious stimulation (40 degrees C) of the small diameter afferents is not a sufficiently intense sensory stimulation to alter the control of posture. A painful stimulation (45 degrees C) of the skin thermoreceptors, however, yielded a deterioration of the postural control system. The observed deteriorating effects of the combined stimulation of nociceptors and Ia afferents (when ankle tendons were vibrated) could result from the convergence of these afferents at the spinal level. This could certainly lead to the hypothesis that individuals suffering from lower limb pain present alterations of the postural control mechanisms; especially populations already at risk of falling (for example, frail elderly) or populations suffering from concomitant lower limb pain and sensory deficits (for example, diabetic polyneuropathy).

Design and study of deep laser acupuncture stimulator of modulation and multibeam

NASA Astrophysics Data System (ADS)

Mao, Haitao; Wang, Qingguo; Xing, Qian; Li, Fangzheng; Cheng, Dongan

2002-04-01

The laser acupuncture stimulation has been applied extensively to replace the acupuncture needles. But the laser is transmitted to the acupoint through the skin, so the curative effect of the laser irradiation on an acupoint from cuticle is limited. We have developed the deep laser acupuncture stimulator of modulation and multibeam. The laser beam (such as He-Ne, LD, etc.) is turned into the modulated waveform. The modulated laser beam can simulate the customary acupuncture way such as twirling and rotating, etc. The laser beam is split into 3-8 beams by the means of optical shunt. After that they enter into laser acupuncture pins separately through the optical fiber joiners. The laser beam and pins can give simultaneously the stimulation in the depths of 3-8 acupoints. It has been proved by the clinical practice that the deep laser acupuncture has the notable efficiency for the apoplexy and sequelae of apoplexy, sciatica, rheumatoid arthritis, etc.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

PubMed Central

Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon

2016-01-01

Background Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. Materials and Methods We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Results Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, −21.59 mm; 95% CI, −34.25, −8.94; p = 0.0008). Conclusions Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias. PMID:27911934

Infrared laser in the treatment of craniomandibular disorders, arthrogenous pain.

PubMed

Hansson, T L

1989-05-01

The fast removal of intra-articular inflammation of the temporomandibular joint in five different patients after infrared laser application is described. Parameters of clinical evaluation was maximum mouth opening and subjective pain. The application of infrared laser of 700 Hz frequency for 3 minutes during five consecutive days at the skin over the painful area of the temporomandibular joint was used. However, the importance of concomitant mandibular stabilization is stressed to achieve optimal result.

Transcranial infrared laser stimulation improves rule-based, but not information-integration, category learning in humans.

PubMed

Blanco, Nathaniel J; Saucedo, Celeste L; Gonzalez-Lima, F

2017-03-01

This is the first randomized, controlled study comparing the cognitive effects of transcranial laser stimulation on category learning tasks. Transcranial infrared laser stimulation is a new non-invasive form of brain stimulation that shows promise for wide-ranging experimental and neuropsychological applications. It involves using infrared laser to enhance cerebral oxygenation and energy metabolism through upregulation of the respiratory enzyme cytochrome oxidase, the primary infrared photon acceptor in cells. Previous research found that transcranial infrared laser stimulation aimed at the prefrontal cortex can improve sustained attention, short-term memory, and executive function. In this study, we directly investigated the influence of transcranial infrared laser stimulation on two neurobiologically dissociable systems of category learning: a prefrontal cortex mediated reflective system that learns categories using explicit rules, and a striatally mediated reflexive learning system that forms gradual stimulus-response associations. Participants (n=118) received either active infrared laser to the lateral prefrontal cortex or sham (placebo) stimulation, and then learned one of two category structures-a rule-based structure optimally learned by the reflective system, or an information-integration structure optimally learned by the reflexive system. We found that prefrontal rule-based learning was substantially improved following transcranial infrared laser stimulation as compared to placebo (treatment X block interaction: F(1, 298)=5.117, p=0.024), while information-integration learning did not show significant group differences (treatment X block interaction: F(1, 288)=1.633, p=0.202). These results highlight the exciting potential of transcranial infrared laser stimulation for cognitive enhancement and provide insight into the neurobiological underpinnings of category learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Deep brain stimulation for phantom limb pain.

PubMed

Bittar, Richard G; Otero, Sofia; Carter, Helen; Aziz, Tipu Z

2005-05-01

Phantom limb pain is an often severe and debilitating phenomenon that has been reported in up to 85% of amputees. Its pathophysiology is poorly understood. Peripheral and spinal mechanisms are thought to play a role in pain modulation in affected individuals; however central mechanisms are also likely to be of importance. The neuromatrix theory postulates a genetically determined representation of body image, which is modified by sensory input to create a neurosignature. Persistence of the neurosignature may be responsible for painless phantom limb sensations, whereas phantom limb pain may be due to abnormal reorganisation within the neuromatrix. This study assessed the clinical outcome of deep brain stimulation of the periventricular grey matter and somatosensory thalamus for the relief of chronic neuropathic pain associated with phantom limb in three patients. These patients were assessed preoperatively and at 3 month intervals postoperatively. Self-rated visual analogue scale pain scores assessed pain intensity, and the McGill Pain Questionnaire assessed the quality of the pain. Quality of life was assessed using the EUROQOL EQ-5D scale. Periventricular gray stimulation alone was optimal in two patients, whilst a combination of periventricular gray and thalamic stimulation produced the greatest degree of relief in one patient. At follow-up (mean 13.3 months) the intensity of pain was reduced by 62% (range 55-70%). In all three patients, the burning component of the pain was completely alleviated. Opiate intake was reduced in the two patients requiring morphine sulphate pre-operatively. Quality of life measures indicated a statistically significant improvement. This data supports the role for deep brain stimulation in patients with phantom limb pain. The medical literature relating to the epidemiology, pathogenesis, and treatment of this clinical entity is reviewed in detail.

Effect of laser on pain relief and wound healing of recurrent aphthous stomatitis: a systematic review.

PubMed

Suter, Valerie G A; Sjölund, Sophia; Bornstein, Michael M

2017-05-01

The aim of this systematic review was to assess a potential benefit of laser use in the treatment of recurrent aphthous stomatitis (RAS). The primary outcome variables were pain relief, duration of wound healing and reduction in episode frequency. A PICO approach was used as a search strategy in Medline, Embase and Cochrane databases. After scanning and excluding titles, abstracts and full texts, 11 studies (ten RCTs and one non-randomised controlled trial) were included. Study selection and data extraction was done by two observers. Study participants varied between 7-90 for the laser and 5-90 for the control groups. Laser treatment included Nd:YAG laser ablation, CO 2 laser applied through a transparent gel (non-ablative) and diode laser in a low-level laser treatment (LLLT) mode. Control groups had placebo, no therapy or topical corticosteroid treatment. Significant pain relief immediately after treatment was found in five out of six studies. Pain relief in the days following treatment was recorded in seven studies. The duration of RAS wound healing was also reduced in five studies. However, criteria of evaluation differed between the studies. The episode frequency was not evaluated as only one study addressed this outcome parameter, but did not discriminate between the study (LLLT) and control (corticosteroid) groups. Jadad scores (ranging from 0 to 5) for quality assessment of the included studies range between 0 and 2 (mean = 1.0) for studies analysing pain relief and between 0 and 3 (mean = 1.1) for studies evaluating wound healing. The use of lasers (CO 2 laser, Nd:YAG laser and diode laser) to relieve symptoms and promote healing of RAS is a therapeutic option. More studies for laser applications are necessary to demonstrate superiority over topical pharmaceutical treatment and to recommend a specific laser type, wavelength, power output and applied energy (ablative versus photobiomodulation).

Spinal cord stimulation to abort painful spasms of atypical stiff limb syndrome.

PubMed

Ughratdar, I; Sivakumar, G; Basu, S

2010-01-01

Stiff limb syndrome (SLS) is a rare chronic condition which can result in significant debility. We report the case of a 44-year-old man suffering from severe painful spasms in his right leg with a diagnosis of SLS. He had been initially treated for his pain with a spinal cord stimulator but presented with exacerbation of pain secondary to a lead fracture for which he underwent revision of the stimulator. Postoperative programming unexpectedly resulted in not only control of his pain but also an ability to abort his spasmodic episodes related to SLS. To our knowledge, spinal cord stimulation has not been previously used for SLS and our report opens up another avenue for this rare condition. We provide a brief overview of SLS and propose an underlying mechanism for the observed phenomenon.

Laser therapy in cardiovascular disease

NASA Astrophysics Data System (ADS)

Rindge, David

2009-02-01

Cardiovascular disease is the number one cause of death worldwide. It is broadly defined to include anything which adversely affects the heart or blood vessels. One-third of Americans have one or more forms of it. By one estimate, average human life expectancy would increase by seven years if it were eliminated. The mainstream medical model seeks mostly to "manage" cardiovascular disease with pharmaceuticals or to surgically bypass or reopen blocked vessels via angioplasty. These methods have proven highly useful and saved countless lives. Yet drug therapy may be costly and ongoing, and it carries the risk of side effects while often doing little or nothing to improve underlying health concerns. Similarly, angioplasty or surgery are invasive methods which entail risk. Laser therapy1 regenerates tissue, stimulates biological function, reduces inflammation and alleviates pain. Its efficacy and safety have been increasingly well documented in cardiovascular disease of many kinds. In this article we will explore the effects of laser therapy in angina, atherosclerosis, coronary artery disease, hypertension, hyperlipidemia, myocardial infarction, stroke and other conditions. The clinical application of various methods of laser therapy, including laserpuncture and transcutaneous, supravascular and intravenous irradiation of blood will be discussed. Implementing laser therapy in the treatment of cardiovascular disease offers the possibility of increasing the health and wellbeing of patients while reducing the costs and enhancing safety of medical care.

US-Guided Femoral and Sciatic Nerve Blocks for Analgesia During Endovenous Laser Ablation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yilmaz, Saim, E-mail: ysaim@akdeniz.edu.tr; Ceken, Kagan; Alimoglu, Emel

2013-02-15

Endovenous laser ablation may be associated with significant pain when performed under standard local tumescent anesthesia. The purpose of this study was to investigate the efficacy of femoral and sciatic nerve blocks for analgesia during endovenous ablation in patients with lower extremity venous insufficiency. During a 28-month period, ultrasound-guided femoral or sciatic nerve blocks were performed to provide analgesia during endovenous laser ablation in 506 legs and 307 patients. The femoral block (n = 402) was performed at the level of the inguinal ligament, and the sciatic block at the posterior midthigh (n = 124), by injecting a diluted lidocainemore » solution under ultrasound guidance. After the blocks, endovenous laser ablations and other treatments (phlebectomy or foam sclerotherapy) were performed in the standard fashion. After the procedures, a visual analogue pain scale (1-10) was used for pain assessment. After the blocks, pain scores were 0 or 1 (no pain) in 240 legs, 2 or 3 (uncomfortable) in 225 legs, and 4 or 5 (annoying) in 41 legs. Patients never experienced any pain higher than score 5. The statistical analysis revealed no significant difference between the pain scores of the right leg versus the left leg (p = 0.321) and between the pain scores after the femoral versus sciatic block (p = 0.7). Ultrasound-guided femoral and sciatic nerve blocks may provide considerable reduction of pain during endovenous laser and other treatments, such as ambulatory phlebectomy and foam sclerotherapy. They may make these procedures more comfortable for the patient and easier for the operator.« less

A Study of the Influence of Low Intensity Laser Therapy on Painful Temporomandibular Disorder Patients

PubMed Central

Sattayut, S.; Bradley, P.

2012-01-01

A double-blind clinical trial was conducted on 30 female Temporomandibular Disorders (TMD) patients who had pain as a chief complaint. The patients were randomly allocated into three groups based on Low Intensity Laser (LILT) regimes namely 820 nm Gallium Aluminium Arsenide (GaAlAs) laser at energy densities of 21.4J/cm2, 107 J/cm2 and placebo laser. Each patient had three LILT treatments in a week. The pressure pain threshold (PPT) of trigger points in masticatory muscles, unassisted maximum mouth opening without pain (MOSP) and symptom severity index (SSI) were recorded as baseline data and monitored after every treatment. Jaw kinesiology, electromyography (EMG) and pain rating index from McGill pain questionnaire were also recorded as baseline and final results. The analysis of covariance and further analysis showed that the higher energy density laser group had significant increases in PPT and EMG amplitude recorded from voluntary clenching (cEMG) compared with the placebo group at P values 0.0001 and 0.022 respectively. A significantly greater number of patients recovered from myofascial pain and TMJ arthralgia as assessed clinically in the higher energy group compared with the placebo (P value = 0.02 and 0.006 respectively). There was no statistically significant difference in the other parameters of assessment among the groups at a P value 0.05. At a period of 2 to 4 weeks review after LILT, there was an average 52% reduction of pain as assessed by SSI. PMID:24511188

Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation.

PubMed

Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

2015-07-16

Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

PubMed Central

Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

2015-01-01

Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes. PMID:26193273

Quick Discrimination of Adelta and C Fiber Mediated Pain Based on Three Verbal Descriptors

PubMed Central

Beissner, Florian; Brandau, Amadeus; Henke, Christian; Felden, Lisa; Baumgärtner, Ulf; Treede, Rolf-Detlef; Oertel, Bruno G.; Lötsch, Jörn

2010-01-01

Background Aδ and C fibers are the major pain-conducting nerve fibers, activate only partly the same brain areas, and are differently involved in pain syndromes. Whether a stimulus excites predominantly Aδ or C fibers is a commonly asked question in basic pain research but a quick test was lacking so far. Methodology/Principal Findings Of 77 verbal descriptors of pain sensations, “pricking”, “dull” and “pressing” distinguished best (95% cases correctly) between Aδ fiber mediated (punctate pressure produced by means of von Frey hairs) and C fiber mediated (blunt pressure) pain, applied to healthy volunteers in experiment 1. The sensation was assigned to Aδ fibers when “pricking” but neither “dull” nor “pressing” were chosen, and to C fibers when the sum of the selections of “dull” or “pressing” was greater than that of the selection of “pricking”. In experiment 2, with an independent cohort, the three-descriptor questionnaire achieved sensitivity and specificity above 0.95 for distinguishing fiber preferential non-mechanical induced pain (laser heat, exciting Aδ fibers, and 5-Hz electric stimulation, exciting C fibers). Conclusion A three-item verbal rating test using the words “pricking”, “dull”, and “pressing” may provide sufficient information to characterize a pain sensation evoked by a physical stimulus as transmitted via Aδ or via C fibers. It meets the criteria of a screening test by being easy to administer, taking little time, being comfortable in handling, and inexpensive while providing high specificity for relevant information. PMID:20886070

An experimental study of pain upon stimulation of the nasal and sinus cavities.

PubMed

Clerico, Dean M

2014-01-01

To map different areas of pain sensitivity and to determine the existence and/or pattern of referred pain from upon stimulating the sinonasal cavity. Experimental human study. Mechanical and electrical stimulations to various anatomical structures and areas of the nasal and sinus cavities were conducted on nine volunteers. Intensity, location and character of pain were recorded in all subjects. The postero-superior (cephalic) aspect of the nasal cavity, primarily the anterior face of the sphenoid sinus and the superior turbinate, were the most sensitive sites, and the antero-inferior (caudal) region was the least sensitive. Referred pain to the head and face was reported by several subjects. Topographical differences in pain sensitivity exist in the sinonasal cavity. The phenomenon of referred pain from the nasal cavity was demonstrated. Copyright © 2014 Elsevier Inc. All rights reserved.

Motor cortex stimulation and neuropathic pain: how does motor cortex stimulation affect pain-signaling pathways?

PubMed

Kim, Jinhyung; Ryu, Sang Baek; Lee, Sung Eun; Shin, Jaewoo; Jung, Hyun Ho; Kim, Sung June; Kim, Kyung Hwan; Chang, Jin Woo

2016-03-01

Neuropathic pain is often severe. Motor cortex stimulation (MCS) is used for alleviating neuropathic pain, but the mechanism of action is still unclear. This study aimed to understand the mechanism of action of MCS by investigating pain-signaling pathways, with the expectation that MCS would regulate both descending and ascending pathways. Neuropathic pain was induced in Sprague-Dawley rats. Surface electrodes for MCS were implanted in the rats. Tactile allodynia was measured by behavioral testing to determine the effect of MCS. For the pathway study, immunohistochemistry was performed to investigate changes in c-fos and serotonin expression; micro-positron emission tomography (mPET) scanning was performed to investigate changes of glucose uptake; and extracellular electrophysiological recordings were performed to demonstrate brain activity. MCS was found to modulate c-fos and serotonin expression. In the mPET study, altered brain activity was observed in the striatum, thalamic area, and cerebellum. In the electrophysiological study, neuronal activity was increased by mechanical stimulation and suppressed by MCS. After elimination of artifacts, neuronal activity was demonstrated in the ventral posterolateral nucleus (VPL) during electrical stimulation. This neuronal activity was effectively suppressed by MCS. This study demonstrated that MCS effectively attenuated neuropathic pain. MCS modulated ascending and descending pain pathways. It regulated neuropathic pain by affecting the striatum, periaqueductal gray, cerebellum, and thalamic area, which are thought to regulate the descending pathway. MCS also appeared to suppress activation of the VPL, which is part of the ascending pathway.

Transcranial Direct Current Stimulation (tDCS) Targeting Left Dorsolateral Prefrontal Cortex Modulates Task-Induced Acute Pain in Healthy Volunteers

PubMed Central

Mariano, Timothy Y.; Wout, Mascha van't; Garnaat, Sarah L.; Rasmussen, Steven A.; Greenberg, Benjamin D.

2016-01-01

Objective Current chronic pain treatments target nociception rather than affective “suffering” and its associated functional and psychiatric comorbidities. Left dorsolateral prefrontal cortex (DLPFC) has been implicated in affective, cognitive, and attentional aspects of pain and is a primary target of neuromodulation for affective disorders. Transcranial direct current stimulation (tDCS) can noninvasively modulate cortical activity. The present study tests if anodal tDCS targeting left DLPFC will increase tolerability of acute painful stimuli versus cathodal tDCS. Methods Forty tDCS-naive healthy volunteers received anodal and cathodal stimulation targeting left DLPFC in two randomized and counterbalanced sessions. During stimulation, each participant performed cold pressor (CP) and breath holding (BH) tasks. We measured pain intensity with the Defense and Veterans Pain Rating Scale (DVPRS) before and after each task. Results Mixed ANOVA revealed no main effect of stimulation polarity for mean CP threshold, tolerance, or endurance, or mean BH time (all p > 0.27). However, DVPRS rise associated with CP was significantly smaller with anodal versus cathodal tDCS (p = 0.024). We further observed a significant tDCS polarity × stimulation order interaction (p = 0.042) on CP threshold suggesting task sensitization. Conclusions Although our results do not suggest that polarity of tDCS targeting left DLPFC differentially modulates tolerability of CP- and BH-related pain distress in healthy volunteers, there was a significant effect on DVPRS pain ratings. This contrasts with our previous findings that tDCS targeting left dorsal anterior cingulate cortex showed a trend towards higher mean CP tolerance with cathodal versus anodal stimulation. The present results may suggest tDCS-related effects on nociception or DLPFC-mediated attention, or preferential modulation of the affective valence of pain as captured by DVPRS. Sham-controlled clinical studies are needed. PMID:26814276

Postoperative discomfort after Nd:YAG laser and conventional frenectomy: comparison of both genders.

PubMed

Akpınar, A; Toker, H; Lektemur Alpan, A; Çalışır, M

2016-03-01

Evidence has suggested that males and females experience and report feeling pain differently. The aim of this study was to determine the postoperative perception levels of both females and males after neodymium-doped yttrium aluminum garnet (Nd:YAG) laser frenectomy and conventional frenectomy, and to compare the perceptions between genders. Eighty-nine patients requiring frenectomy were randomly assigned to have treatment with either the conventional frenectomy or with the Nd:YAG laser. Postoperative discomfort (pain, chewing, talking) was recorded using a visual analog scale (VAS) on the operation day and postoperative days 1, 3, 7 and 10. According to the female VAS scores of the pain, chewing and speaking discomfort were statistically higher in the conventional group than those of the laser group on the operation day, and on the first and third postoperative days. Pain discomfort in males was statistically higher in the conventional group than those of the laser group on the operation day. Speaking discomfort in males was statistically higher in the conventional group than those of the laser group on the operation day and the first postoperative day. The present study indicated that Nd:YAG laser treatment used for frenectomies provides better postoperative comfort for each gender, especially in females in terms of pain, chewing and speaking than the conventional procedure up to the seventh postoperative day. According to our results, Nd:YAG laser may provide a safe, bloodless, painless surgery and an impressive alternative for frenectomy operations. © 2015 Australian Dental Association.

Neural Activation during Anticipation of Near Pain-Threshold Stimulation among the Pain-Fearful.

PubMed

Yang, Zhou; Jackson, Todd; Huang, Chengzhi

2016-01-01

Fear of pain (FOP) can increase risk for chronic pain and disability but little is known about corresponding neural responses in anticipation of potential pain. In this study, more (10 women, 6 men) and less (7 women, 6 men) pain-fearful groups underwent whole-brain functional magnetic resonance imaging (fMRI) during anticipation of near pain-threshold stimulation. Groups did not differ in the proportion of stimuli judged to be painful but pain-fearful participants reported significantly more state fear prior to stimulus exposure. Within the entire sample, stronger activation was found in several pain perception regions (e.g., bilateral insula, midcingulate cortex (MCC), thalamus, superior frontal gyrus) and visual areas linked to decoding stimulus valences (inferior orbital cortex) during anticipation of "painful" stimuli. Between groups and correlation analyses indicated pain-fearful participants experienced comparatively more activity in regions implicated in evaluating potential threats and processing negative emotions during anticipation (i.e., MCC, mid occipital cortex, superior temporal pole), though group differences were not apparent in most so-called "pain matrix" regions. In sum, trait- and task-based FOP is associated with enhanced responsiveness in regions involved in threat processing and negative affect during anticipation of potentially painful stimulation.

Utility of Vibratory Stimulation for Reducing Intraoral Injection Pain.

PubMed

Erdogan, Ozgur; Sinsawat, Anatachai; Pawa, Sudeep; Rintanalert, Duangtawan; Vuddhakanok, Suchada

2018-01-01

Intraoral local anesthesia injection is often perceived as a painful and anxiety-causing dental procedure. Vibration stimulus is one of the nonpharmacologic methods used to reduce unwanted sensations of local anesthesia injection. This clinical study evaluated the effectiveness of a recently introduced vibratory stimulation device in intraoral local anesthesia administration. Thirty-two subjects underwent 2 maxillary local anesthesia injections in 2 different sessions: 1 with conventional techniques and 1 with the aid of a vibratory stimulation device (DentalVibe). The pain levels were evaluated with a visual analog scale and the Wong-Baker FACES Pain Rating Scale. The subjects were asked to choose the preferred method for future injections. The data were evaluated statistically. There were no significant differences between the 2 injection methods with regard to either pain evaluation method. The preference of the subjects regarding future injection technique was evenly distributed between the groups. The vibratory stimulation device used in this study did not provide any reduction in pain level associated with maxillary infiltration local anesthesia administration.

DRG Spinal Cord Stimulation as Solution for Patients With Severe Pain Due to Anterior Cutaneous Nerve Entrapment Syndrome: A Case Series.

PubMed

Mol, Frédérique Mathilde Ulrike; Roumen, Rudi M H

2018-04-01

Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is a debilitating neuropathic pain condition. A small portion of patients do not respond to any currently available treatment modalities. These patients, often young women, might benefit from targeted spinal cord stimulation of the dorsal root ganglion (DRG). This retrospective case series describes five ACNES patients who were referred from a Dutch dedicated tertiary referral center to collaborating sites with extensive experience in DRG stimulation to be implanted with a DRG Axium System (St. Jude/Abbott, IL, USA) in the period of 2013-2016. Numeric pain rating scores at routine 6- and 12-month follow-up visits were analyzed. Three patients experienced >50% pain reduction at 12 months follow-up. Four patients experienced device-related complications, such as lead dislocation, lead breakage, pain at the battery site, and overstimulation. This case series suggests DRG spinal cord stimulation can be safe and effective for some patients with persistent pain due to ACNES. © 2017 International Neuromodulation Society.

Signal and response properties indicate an optoacoustic effect underlying the intra-cochlear laser-optical stimulation

NASA Astrophysics Data System (ADS)

Kallweit, Nicole; Baumhoff, Peter; Krueger, Alexander; Tinne, Nadine; Heisterkamp, Alexander; Kral, Andrej; Maier, Hannes; Ripken, Tammo

2016-02-01

Optical cochlea stimulation is under investigation as a potential alternative to conventional electric cochlea implants in treatment of sensorineural hearing loss. If direct optical stimulation of spiral ganglion neurons (SGNs) would be feasible, a smaller stimulation volume and, therefore, an improved frequency resolution could be achieved. However, it is unclear whether the mechanism of optical stimulation is based on direct neuronal stimulation or on optoacoustics. Animal studies on hearing vs. deafened guinea pigs already identified the optoacoustic effect as potential mechanism for intra-cochlear optical stimulation. In order to characterize the optoacoustic stimulus more thoroughly the acoustic signal along the beam path of a pulsed laser in water was quantified and compared to the neuronal response properties of hearing guinea pigs stimulated with the same laser parameters. Two pulsed laser systems were used for analyzing the influence of variable pulse duration, pulse energy, pulse peak power and absorption coefficient. Preliminary results of the experiments in water and in vivo suggesta similar dependency of response signals on the applied laser parameters: Both datasets show an onset and offset signal at the beginning and the end of the laser pulse. Further, the resulting signal amplitude depends on the pulse peak power as well as the temporal development of the applied laser pulse. The data indicates the maximum of the first derivative of power as the decisive factor. In conclusion our findings strengthen the hypothesis of optoacoustics as the underlying mechanism for optical stimulation of the cochlea.

Near infrared low level laser therapy and cell proliferation: the emerging role of redox sensitive signal transduction pathways.

PubMed

Migliario, Mario; Sabbatini, Maurizio; Mortellaro, Carmen; Renò, Filippo

2018-05-02

Lasers devices are widely used in various medical fields (e.g. surgery, dermatology, dentistry, rehabilitative medicine, etc) for different applications, ranging from surgical ablation of tissues to biostimulation and pain relief. Laser is an electromagnetic radiation which effects on biological tissues strongly depends on a number of physical parameters. Laser wavelength, energy output, irradiation time and modality, temperature and tissue penetration properties have to be set up according to the clinical target tissue and the desired effect. A less than optimal operational settings, in fact, could result in a null or even lethal effect. According to the first law of photobiology, light absorption requires the presence of a specific photoacceptor that after excitation could induce the activation of downstream signaling pathways. Low level lasers operating in the red/near infrared portion of the light spectra are generally used for biostimulation purposes, a particular therapeutic application based on the radiant energy ability to induce non-thermal responses in living cells. Biostimulation process generally promotes cell survival and proliferation. Emerging evidences support a low level laser stimulation mediated increase in "good" ROS (reactive oxygen species), able to activate redox sensitive signal transduction pathways such as Nrf-2, NF-kB, ERK which act as key redox checkpoints. This article is protected by copyright. All rights reserved.

Investigation of human frontal cortex under noxious thermal stimulation of temporo-mandibular joint using functional near infrared spectroscopy

NASA Astrophysics Data System (ADS)

Yennu, Amarnath; Rawat, Rohit; Manry, Michael T.; Gatchel, Robert; Liu, Hanli

2013-03-01

According to American Academy of Orofacial Pain, 75% of the U.S. population experiences painful symptoms of temporo-mandibular joint and muscle disorder (TMJMD) during their lifetime. Thus, objective assessment of pain is crucial for efficient pain management. We used near infrared spectroscopy (NIRS) as a tool to explore hemodynamic responses in the frontal cortex to noxious thermal stimulation of temporomadibular joint (TMJ). NIRS experiments were performed on 9 healthy volunteers under both low pain stimulation (LPS) and high pain stimulation (HPS), using a temperature-controlled thermal stimulator. To induce thermal pain, a 16X16 mm2 thermode was strapped onto the right TMJ of each subject. Initially, subjects were asked to rate perceived pain on a scale of 0 to 10 for the temperatures from 41°C to 47°C. For the NIRS measurement, two magnitudes of temperatures, one rated as 3 and another rated as 7, were chosen as LPS and HPS, respectively. By analyzing the temporal profiles of changes in oxy-hemoglobin concentration (HbO) using cluster-based statistical tests, we were able to identify several regions of interest (ROI), (e.g., secondary somatosensory cortex and prefrontal cortex), where significant differences (p<0.05) between HbO responses to LPS and HPS are shown. In order to classify these two levels of pain, a neural-network-based classification algorithm was used. With leave-one-out cross validation from 9 subjects, the two levels of pain were identified with 100% mean sensitivity, 98% mean specificity and 99% mean accuracy to high pain. From the receiver operating characteristics curve, 0.99 mean area under curve was observed.

Tri-length laser therapy associated to tecar therapy in the treatment of low-back pain in adults: a preliminary report of a prospective case series.

PubMed

Osti, Raffaella; Pari, Carlotta; Salvatori, Giada; Massari, Leo

2015-01-01

Low-back pain is very frequent, especially in active adult population. There are several different orthopaedic condition that can cause low-back pain, and the pain worsen the quality of life significantly. The treatments vary from drugs, physical therapies, kinesiology, local infiltrations, and so on. Laser therapy has an important role in the treatment of the inflammatory causes of pain, with several studies that demonstrate the efficacy of low and high energy laser therapy in the treatment of low-back pain. Sixty-six consecutive patients with low-back pain with or without leg pain were treated using a combination of Tri-length laser I-Triax® (Mectronic Medicale, Bergamo, Italy) and Pharon® tecar therapy (Mectronic Medicale, Bergamo, Italy). The patients were treated three times a week, every other day, for a total of 10 sessions. Clinical results were evaluated using visual analogic scale for individual pain (0 to 10) and the Oswestry disability scale (ODS). Tests started before the beginning of therapies and 8 weeks after the end of the therapies. Visual analogic scale (VAS) score significantly improved from an average value of 8.1 ± 1.58 pre-treatment to an average value 8-weeks post-treatment of 2.63 ± 2.74 (P < .01). ODS values start from a pre-treatment average value of 53.0 ± 13.0 to a post-treatment average value of 23.5 ± 19.8 (P < .01). A higher improvement both in VAS and in ODS was denoted in the group of patient with low-back pain and leg pain (respectively, VAS from 8.66 ± 1.58 to 2.86 ± 2.94 and ODS from 57.8 ± 15.5 to 23.7 ± 19.5). Low-back pain, associated or not with leg pain, is a very common clinical situation. The treatments of this condition are different, and an important role can be given to the laser therapy. The conclusion of this study is that the association between laser therapy iLux-Triax® and tecar therapy Pharon® in the treatment of low-back pain, with or without leg pain, can significantly reduce pain and improve the quality of life in patients with degenerative and inflammatory problems.

Effect of Fixed Versus Adjusted Transcutaneous Electrical Nerve Stimulation Amplitude on Chronic Mechanical Low Back Pain.

PubMed

Elserty, Noha; Kattabei, Omaima; Elhafez, Hytham

2016-07-01

This study aimed to investigate the effect of adjusting pulse amplitude of transcutaneous electrical nerve stimulation versus fixed pulse amplitude in treatment of chronic mechanical low back pain. Randomized clinical trial. El-sahel Teaching Hospital, Egypt. Forty-five patients with chronic low back pain assigned to three equal groups. Their ages ranged from 20 to 50 years. The three groups received the same exercise program. Group A received transcutaneous electrical nerve stimulation with fixed pulse amplitude for 40 minutes. Group B received transcutaneous electrical nerve stimulation with adjusted pulse amplitude for 40 minutes, with the pulse amplitude adjusted every 5 minutes. Group C received exercises only. Treatment sessions were applied three times per week for 4 weeks for the three groups. A visual analogue scale was used to assess pain severity, the Oswestry Disability Index was used to assess functional level, and a dual inclinometer was used to measure lumbar range of motion. Evaluations were performed before and after treatment. Visual analogue scale, Oswestry Disability Index, and back range of motion significantly differed between the two groups that received transcutaneous electrical nerve stimulation and the control group and did not significantly differ between fixed and adjusted pulse amplitude of transcutaneous electrical nerve stimulation. Adjusting pulse amplitude of transcutaneous electrical nerve stimulation does not produce a difference in the effect of transcutaneous electrical nerve stimulation used to treat chronic low back pain.

Comparative Evaluation of the Effects of Nd:YAG Laser and a Desensitizer Agent on the Treatment of Dentin Hypersensitivity: A Clinical Study

PubMed Central

Lopes, Anely Oliveira

2013-01-01

Abstract Objective: The aim of this randomized longitudinal clinical study was to assess different treatment protocols for dentin hypersensitivity with high-power laser, desensitizing agent, and its association between high-power laser and desensitizing agent, for a period of 6 months. Background data: The literature shows a lack of treatment for dentin hypersensitivity, and lasers are contemporary alternatives. Methods: After inclusion and exclusion analysis, volunteers were selected. The lesions were divided into three groups (n=10): G1, Gluma Desensitizer (Heraeus Kulzer); G2, Nd:YAG Laser (Power Laser™ ST6, Lares Research®) contact mode, laser protocol of 1.5 W, 10 Hz, and 100 mJ,≈85 J/cm2, four irradiations performed, each for 15 sec, in mesiodistal and occluso-apical directions, totaling 60 sec of irradiation with intervals of 10 sec between them; G3, Nd:YAG Laser+Gluma Desensitizer. The level of sensitivity to pain of each volunteer was analyzed by visual analog scale (VAS) using cold air stimuli and exploratory probe 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis that detected statistically significant differences between the various studied time intervals of treatments (p>0.05). Results: For the air stimulus, no significant differences were found for each time interval. For the long-term evaluation, all groups showed statistical differences (p>0.05), indicating that for G2 and G3, this difference was statistically significant from the first time of evaluation (post 1), whereas in G1, the difference was significant from the post 2 evaluation (1 week). Comparison among groups using the probe stimulation showed significant differences in pain (p<0.001). Only in G1 and G3 did this difference become significant from post 01. Conclusions: All protocols were effective in reducing dentinal hypersensitivity after 6 months of treatment; however, the association of Nd:YAG and Gluma Desensitizer is an effective treatment strategy that has immediate and long-lasting effects. PMID:23421629

Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

PubMed

Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

2015-11-01

In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

Evaluation of afferent pain pathways in adrenomyeloneuropathic patients.

PubMed

Yagüe, Sara; Veciana, Misericordia; Casasnovas, Carlos; Ruiz, Montserrat; Pedro, Jordi; Valls-Solé, Josep; Pujol, Aurora

2018-03-01

Patients with adrenomyeloneuropathy may have dysfunctions of visual, auditory, motor and somatosensory pathways. We thought on examining the nociceptive pathways by means of laser evoked potentials (LEPs), to obtain additional information on the pathophysiology of this condition. In 13 adrenomyeloneuropathic patients we examined LEPs to leg, arm and face stimulation. Normative data were obtained from 10 healthy subjects examined in the same experimental conditions. We also examined brainstem auditory evoked potentials (BAEPs), pattern reversal full-field visual evoked potentials (VEPs), motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs). Upper and lower limb MEPs and SEPs, as well as BAEPs, were abnormal in all patients, while VEPs were abnormal in 3 of them (23.1%). LEPs revealed abnormalities to stimulation of the face in 4 patients (30.7%), the forearm in 4 patients (30.7%) and the leg in 10 patients (76.9%). The pathologic process of adrenomyeloneuropathy is characterized by a preferential involvement of auditory, motor and somatosensory tracts and less severely of the visual and nociceptive pathways. This non-inflammatory distal axonopathy preferably damages large myelinated spinal tracts but there is also partial involvement of small myelinated fibres. LEPs studies can provide relevant information about afferent pain pathways involvement in adrenomyeloneuropathic patients. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Low Energy Laser Biostimulation: New Prospects For Medical Applications

NASA Astrophysics Data System (ADS)

Castel, John C.; Abergel, R. Patrick; Willner, Robert E.; Baumann, James G.

1987-03-01

The therapeutic benefits of light-energy is not a new concept to the modern world. Documented applications from ancient times tell of the therapeutic effects of ordinary sun-light to treat such common ailments as painful body joints, wounds, compound fractures and tetanus. The discovery of laser light in the 1960's, opened up new prospects for the medical use of light. Laser light differs from other forms of electromagnetic spectrum in that a single wavelength rather than a spectrum of wavelengths is emitted. Since the early 1970's, low-energy laser radiation has been reported to enhance wound healing rates, reduce edema, and relieve musculoskeletal pain. There is no detectable thermal effect of this laser on the tissue being treated. The effects are considered to occur as a result of photochemical, non thermal effects of the laser beam. Photons are absorbed by the tissue being treated and, in turn, produce positive therapeutic effects such as reduction of pain and edema. Pre-clinical and clinical evaluations are, presently, underway to document the safety and efficacy of low energy laser therapy, which represents a significant advance in the non-invasive treatment of pain.

Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

PubMed Central

Gozani, Shai N

2016-01-01

Objective The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Background Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Methods Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. Results One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non-responders. Conclusion FS-TENS is a safe and effective option for treating chronic low back and lower extremity pain. These results motivate the use of FS-TENS in development of wearable analgesic devices. PMID:27418854

Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain.

PubMed

Gozani, Shai N

2016-01-01

The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non-responders. FS-TENS is a safe and effective option for treating chronic low back and lower extremity pain. These results motivate the use of FS-TENS in development of wearable analgesic devices.

Influence of Electroacupuncture and Laser-Acupuncture on Treating Paresthesia in Patients Submitted to Combined Orthognathic Surgery and Genioplasty

PubMed Central

de Oliveira, Renata F.; Goldman, Ricardo S.; Mendes, Fausto Medeiros

2017-01-01

Abstract Objective: The goal of this research was to observe the influence of electroacupuncture (EA) and laser-acupuncture on the return of tactile/pain sensitivity in patients who underwent orthognathic surgery. Materials and Methods: Thirty volunteers subjected to orthognathic surgery were evaluated and randomly divided into 2 groups, in which 3 treatments were evaluated: control (n = 30) (G0, medication + placebo laser treatment) and 2 experimental treatments (n = 15) (G1, medication + EA) or G2 (medication + laser-acupuncture). The control group had n = 30 because for each experimental treatment conducted on a volunteer's hemi-face, there was a control treatment on the other hemi-face. In G1, medication was given with EA, with needles placed at predetermined points (ST 4 [Dicang], M-HN-18 [Jiachengjiang], CV 24 [Chengjiang], ST 5 [Daying], ST 6 [Jiache], and point A1 [YNSA]). For electrostimulation, the device used delivered transcutaneous electrical nerve stimulation of a burst type, with intensity and frequency variations of T = 220 ms and F = 4 Hz (30 minutes, 2 × /week). In G2, in addition to the medication, laser irradiation (at 780 nm) was applied on acupuncture points (at 0.04 cm2, 70 mW, 6 s/point, 0.42 J/point, 10 J/cm2, 2 × /week). All volunteers were evaluated before and during the 4 months following the surgery. Tactile sensitivity was assessed by mechanical brushing (brush #s 2 and 12) and by a 2-point discrimination test, using a bow compass. A pain test was performed with a pulp electrical test that stimulates intact nerves of the dentin-pulp complex. A Kaplan–Meier test was performed, and survival curves were plotted for comparison between groups. Cox regression analysis was also conducted (α = 0.05). Results: There were no statistically significant differences among the groups for the 2-point discrimination test (brushes #2 and #12) on the buccal mucosa region and for the pulp test on all evaluated regions. However, the tactile test using brush #12 revealed significant differences between G1 and the other groups when considering the lower lip (P = 0.024) and chin (P = 0.028) areas. Conclusions: Only EA was able to influence—using the brushing test (brush #12)—the return of tactile sensitivity on the chin and lower lip positively after combined orthognathic surgery and genioplasty. PMID:29067139

The Fine Tuning of Pain Thresholds: A Sophisticated Double Alarm System

PubMed Central

Plaghki, Léon; Decruynaere, Céline; Van Dooren, Paul; Le Bars, Daniel

2010-01-01

Two distinctive features characterize the way in which sensations including pain, are evoked by heat: (1) a thermal stimulus is always progressive; (2) a painful stimulus activates two different types of nociceptors, connected to peripheral afferent fibers with medium and slow conduction velocities, namely Aδ- and C-fibers. In the light of a recent study in the rat, our objective was to develop an experimental paradigm in humans, based on the joint analysis of the stimulus and the response of the subject, to measure the thermal thresholds and latencies of pain elicited by Aδ- and C-fibers. For comparison, the same approach was applied to the sensation of warmth elicited by thermoreceptors. A CO2 laser beam raised the temperature of the skin filmed by an infrared camera. The subject stopped the beam when he/she perceived pain. The thermal images were analyzed to provide four variables: true thresholds and latencies of pain triggered by heat via Aδ- and C-fibers. The psychophysical threshold of pain triggered by Aδ-fibers was always higher (2.5–3°C) than that triggered by C-fibers. The initial skin temperature did not influence these thresholds. The mean conduction velocities of the corresponding fibers were 13 and 0.8 m/s, respectively. The triggering of pain either by C- or by Aδ-fibers was piloted by several factors including the low/high rate of stimulation, the low/high base temperature of the skin, the short/long peripheral nerve path and some pharmacological manipulations (e.g. Capsaicin). Warming a large skin area increased the pain thresholds. Considering the warmth detection gave a different picture: the threshold was strongly influenced by the initial skin temperature and the subjects detected an average variation of 2.7°C, whatever the initial temperature. This is the first time that thresholds and latencies for pain elicited by both Aδ- and C-fibers from a given body region have been measured in the same experimental run. Such an approach illustrates the role of nociception as a “double level” and “double release” alarm system based on level detectors. By contrast, warmth detection was found to be based on difference detectors. It is hypothesized that pain results from a CNS build-up process resulting from population coding and strongly influenced by the background temperatures surrounding at large the stimulation site. We propose an alternative solution to the conventional methods that only measure a single “threshold of pain”, without knowing which of the two systems is involved. PMID:20428245

Treatment feasibility study of osteoporosis using minimal invasive laser needle system

NASA Astrophysics Data System (ADS)

Kang, Dongyeon; Ko, Chang-Yong; Ryu, Yeon-Hang; Park, Sunwook; Kim, Han-Sung; Jung, Byungjo

2010-02-01

Although the mechanism of laser stimulation effect in bone has not completely understood, laser stimulation is recommended in the treatment of osteoporosis due to positive treatment efficacy. In this study, a minimal invasive laser needle system (MILNS) was developed using a fine hollow needle in order to stimulate directly bone site by guiding an optical fiber. In order to evaluate the MILNS as a treatment method, in-vivo animal experiment study was performed using osteopenic mice. Twelve virginal ICR mice were employed and divided two groups: SHAM-group and LASERgroup. SHARM-group was stimulated by only fine hollow needle and LASER-group by fine hollow needle combined with laser stimulation. All mice were served in-vivo micro-CT images before and after treatment. Three dimensional (3D) structural parameters and vBMD (volume bone mineral density, g/cm3) in the trabecular bone were measured. After 2 weeks of stimulation, the vBMD, BV/TV, Tb.Th and Tb.N in LASER-group were significantly higher than those in SHAM-group (p<0.05). Potentially, this study suggested that the MILNS might prevent the bone loss and maintains the bone mineral density of osteopenic mice.

Assessment of Low-Level Laser Therapy Effects After Extraction of Impacted Lower Third Molar Surgery

PubMed Central

Raiesian, Shahrokh; Khani, Mehdi; Khiabani, Kazem; Hemmati, Ershad; Pouretezad, Mohammad

2017-01-01

Introduction: The aim of this study was to assess the effect of low-level laser therapy (LLLT) on pain, swelling and maximum mouth opening in patients undergoing third molar surgery. Methods: A prospective, randomized double-blind study was undertaken on 44 patients at the Dental School, Ahvaz Jundishapur University of Medical Sciences, in 2015. A low-level laser was randomly applied on one of the two sides after surgery of 15 patients. The experimental side received 18 J/cm2 of energy density, wavelength of 980 nm, and output power of 1.8 W. On the control side, a hand-piece was applied intra-orally, but laser was not activated. In addition, in order to evaluate trismus, 13 patients were treated by unilateral laser therapy and 16 patients did not receive laser therapy at all. The laser was administered intraorally on two points of vestibular and lingual sides at 1 cm from the surgery site, and extraorally at the emergence of the masseter muscle, immediately after surgery, and repeated 24 hours later. The pain, swelling and maximum mouth opening (MMO) were compared between the two groups at 24 hours and a week after surgery. Results: The mean score of pain 24 hours after surgery in the laser therapy group (2.3 ± 3.5) was significantly lower than the mean score of pain in the drug therapy (4.19 ± 3.09) (P = 0.036). Moreover, the mean score of pain at one week after surgery in the laser therapy group (0.13 ± 2.33) was significantly lower than the drug therapy group (1.43 ± 2.45) (P = 0.046). The amount of swelling according to different measurements did not significantly differ between the two groups neither at 24 hours nor at 1 week after surgery. Conclusion: Our findings showed that LLLT was useful in reducing pain and could slightly reduce swelling compared to drug therapy in impacted third molar surgery. PMID:28912943

Increased regional cerebral blood flow in the contralateral thalamus after successful motor cortex stimulation in a patient with poststroke pain.

PubMed

Saitoh, Youichi; Osaki, Yasuhiro; Nishimura, Hiroshi; Hirano, Shun-ichiro; Kato, Amami; Hashikawa, Kazuo; Hatazawa, Jun; Yoshimine, Toshiki

2004-05-01

The mechanisms underlying poststroke pain have not been clearly identified. Although motor cortex stimulation (MCS) sometimes reduces poststroke pain successfully, the exact mechanism is not yet known. For further investigation of the neural pathways involved in the processing of poststroke pain and in pain reduction by MCS, the authors used positron emission tomography (PET) scanning to determine significant changes in regional cerebral blood flow (rCBF). This 58-year-old right-handed man suffered from right-sided poststroke pain for which he underwent implantation of a stimulation electrode in the right motor cortex. After 30 minutes of stimulation, his pain was remarkably reduced (Visual Analog Scale scores decreased 8 to 1) and he felt warmth in his left arm. The rCBF was studied using PET scanning with 15O-labeled water when the patient was in the following states: before MCS (painful condition, no stimulation) and after successful MCS (painless condition, no stimulation). The images were analyzed using statistical parametric mapping software. State-dependent differences in global blood flow were covaried using analysis of covariance. Comparisons of the patient's rCBF in the painful condition with that in the painless condition revealed significant rCBF increases in the left rectus gyrus (BA11), left superior frontal lobe (BA9), left anterior cingulate gyms (BA32), and the left thalamus (p < 0.05, corrected). On the other hand, there were significant decreases in rCBF in the right superior temporal gyrus (BA22, p < 0.01, corrected) and the left middle occipital gyrus (BA19, p < 0.05, corrected). The efficacy of MCS was mainly related to increased synaptic activity in the thalamus, whereas the activations in the rectus gyrus, anterior cingulate gyrus, and superior frontal cortex as well as the inactivation of the superior temporal lobe may be related to emotional processes. This is the first report in which the contralateral thalamus was significantly activated and pain relief was achieved using MCS.

Clinical Effects of Laser Acupuncture plus Chinese Cupping on the Pain and Plasma Cortisol Levels in Patients with Chronic Nonspecific Lower Back Pain: A Randomized Controlled Trial

PubMed Central

Lin, Mu-Lien; Wu, Hung-Chien; Shih, Yong-Sheng; Chiu, I-Ting; Chen, Chao-Yi

2017-01-01

Objectives Chronic nonspecific lower back pain (LBP) is a common disease. Insufficient data is currently available to conclusively confirm the analgesic effects of laser acupuncture on LBP. This study evaluated the effectiveness of laser acupuncture plus Chinese cupping in LBP treatment. Methods Patients with chronic nonspecific LBP were enrolled for a randomized controlled trial and assigned to the laser acupuncture group (laser acupuncture plus Chinese cupping) and control group (sham laser plus Chinese cupping). Laser acupuncture (808 nm; 40 mW; 20 Hz; 15 J/cm2) and Chinese cupping were applied on the Weizhong (BL40) and Ashi acupoints for 5 consecutive days. Plasma cortisol levels were assessed before and after the 5-day treatment session. The visual analog scale (VAS) scores were recorded at baseline and throughout the 5-day treatment session. Results After the treatment session, the plasma cortisol levels and VAS scores decreased significantly in both groups. In the laser acupuncture group, the VAS scores decreased significantly on days 4 and 5, and an enhanced reduction in VAS scores was observed. Conclusion Laser acupuncture plus Chinese cupping at the Weizhong (BL40) and Ashi acupoints effectively reduced pain and inflammation in chronic nonspecific LBP. This therapy could be a suitable option for LBP treatment in clinical settings. PMID:28848615

Clinical Effects of Laser Acupuncture plus Chinese Cupping on the Pain and Plasma Cortisol Levels in Patients with Chronic Nonspecific Lower Back Pain: A Randomized Controlled Trial.

PubMed

Lin, Mu-Lien; Wu, Jih-Huah; Lin, Chi-Wan; Su, Chuan-Tsung; Wu, Hung-Chien; Shih, Yong-Sheng; Chiu, I-Ting; Chen, Chao-Yi; Chang, Wen-Dien

2017-01-01

Chronic nonspecific lower back pain (LBP) is a common disease. Insufficient data is currently available to conclusively confirm the analgesic effects of laser acupuncture on LBP. This study evaluated the effectiveness of laser acupuncture plus Chinese cupping in LBP treatment. Patients with chronic nonspecific LBP were enrolled for a randomized controlled trial and assigned to the laser acupuncture group (laser acupuncture plus Chinese cupping) and control group (sham laser plus Chinese cupping). Laser acupuncture (808 nm; 40 mW; 20 Hz; 15 J/cm 2 ) and Chinese cupping were applied on the Weizhong (BL40) and Ashi acupoints for 5 consecutive days. Plasma cortisol levels were assessed before and after the 5-day treatment session. The visual analog scale (VAS) scores were recorded at baseline and throughout the 5-day treatment session. After the treatment session, the plasma cortisol levels and VAS scores decreased significantly in both groups. In the laser acupuncture group, the VAS scores decreased significantly on days 4 and 5, and an enhanced reduction in VAS scores was observed. Laser acupuncture plus Chinese cupping at the Weizhong (BL40) and Ashi acupoints effectively reduced pain and inflammation in chronic nonspecific LBP. This therapy could be a suitable option for LBP treatment in clinical settings.

Single-trial laser-evoked potentials feature extraction for prediction of pain perception.

PubMed

Huang, Gan; Xiao, Ping; Hu, Li; Hung, Yeung Sam; Zhang, Zhiguo

2013-01-01

Pain is a highly subjective experience, and the availability of an objective assessment of pain perception would be of great importance for both basic and clinical applications. The objective of the present study is to develop a novel approach to extract pain-related features from single-trial laser-evoked potentials (LEPs) for classification of pain perception. The single-trial LEP feature extraction approach combines a spatial filtering using common spatial pattern (CSP) and a multiple linear regression (MLR). The CSP method is effective in separating laser-evoked EEG response from ongoing EEG activity, while MLR is capable of automatically estimating the amplitudes and latencies of N2 and P2 from single-trial LEP waveforms. The extracted single-trial LEP features are used in a Naïve Bayes classifier to classify different levels of pain perceived by the subjects. The experimental results show that the proposed single-trial LEP feature extraction approach can effectively extract pain-related LEP features for achieving high classification accuracy.

Peripheral nerve field stimulation (PNFS) in chronic low back pain: a prospective multicenter study.

PubMed

Kloimstein, Herwig; Likar, Rudolf; Kern, Michael; Neuhold, Josef; Cada, Miroslav; Loinig, Nadja; Ilias, Wilfried; Freundl, Brigitta; Binder, Heinrich; Wolf, Andreas; Dorn, Christian; Mozes-Balla, Eva Maria; Stein, Rolf; Lappe, Ivo; Sator-Katzenschlager, Sabine

2014-02-01

The goal of this study was to evaluate the long-term efficacy and safety of peripheral nerve field stimulation (PNFS) for chronic low back pain (cLBP). In this prospective, multicenter observational study, 118 patients were admitted to 11 centers throughout Austria and Switzerland. After a screening visit, all patients underwent a trial stimulation period of at least seven days before implantation of the permanent system. Leads were placed in the subcutaneous tissues of the lower back directly in the region of greatest pain. One hundred five patients were implanted with a permanent stimulating system. Patients' evaluation of pain and functional levels were completed before implantation and one, three, and six months after implantation. Adverse events, medication usage, and coverage of the painful area and predictive value of transcutaneous electrical nerve stimulation (TENS) were monitored. All pain and quality-of-life measures showed statistically significant improvement during the treatment period. These included the average pain visual analog scale, the Oswestry Disability Questionnaire, the Becks Depression Inventory, and the Short Form-12 item Health survey. Additionally, medication usage with opioids, nonsteroidal anti-inflammatory drugs, and anti-convulsants showed a highly significant reduction. Complications requiring surgical intervention were reported in 9.6% of the patients. The degree of coverage of painful areas seems to be an important criterion for efficacy of PNFS, whereas TENS is presumably no predictor. This prospective, multicenter study confirms that PNFS is an effective therapy for the management of cLBP. Significant improvements in many aspects of the pain condition were measured, and complications were minimal. © 2013 International Neuromodulation Society.

Effects of Therapy in Patients Suffering from Chronic Back Pain Treated with Spinal Cord Stimulation.

PubMed

Mosiewicz, Anna; Rutkowska, Elżbieta; Matacz, Monika; Mosiewicz, Barbara; Kaczmarczyk, Robert; Trojanowski, Tomasz

2015-10-01

Pain in the lumbosacral part of the spine in the course of degenerative disease is the most common cause of physical activity limitation in adults. Treatment includes pharmacotherapy, physiotherapy, psychotherapy, health promotion, and sometimes surgery. Surgical treatment is not always successful, and the various clinical and psychosomatic symptoms that result from surgical treatment failure are known as failed back surgery syndrome. For some patients with this condition, spinal cord stimulation can provide relief. The aim of the work was to define subjective and objective spinal cord stimulation effects by assessing chosen disability and physical activity limitation ratios. Pain intensity, level of disability, and presence of neurological symptoms were assessed. The examination was performed twice: before the stimulator implantation and at least 6 months postimplantation. The study was conducted at the Department of Neurosurgery and Paediatric Neurosurgery in Lublin. Thirty-six patients suffering from failed back surgery syndrome were recruited for this study. The Visual Analog Scale, modified Laitinen's pain questionnaire, and Oswestry Disability Index were used in this work. The study showed that spinal cord stimulation was effective in treating spinal and lower limb pain in 64% of patients, similar to results obtained in other departments. Although back pain and neuropathic pain radiating to the lower limbs decreased, moderate physical activity impairment was still observed according to the Oswestry Disability Index scale. The decrease in neuropathic pain radiating to the lower limbs had the most significant influence on reducing physical activity impairment. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Cerebral somatic pain modulation during autogenic training in fMRI.

PubMed

Naglatzki, R P; Schlamann, M; Gasser, T; Ladd, M E; Sure, U; Forsting, M; Gizewski, E R

2012-10-01

Functional magnetic resonance imaging (fMRI) studies are increasingly employed in different conscious states. Autogenic training (AT) is a common clinically used relaxation method. The purpose of this study was to investigate the cerebral modulation of pain activity patterns due to AT and to correlate the effects to the degree of experience with AT and strength of stimuli. Thirteen volunteers familiar with AT were studied with fMRI during painful electrical stimulation in a block design alternating between resting state and electrical stimulation, both without AT and while employing the same paradigm when utilizing their AT abilities. The subjective rating of painful stimulation and success in modulation during AT was assessed. During painful electrical stimulation without AT, fMRI revealed activation of midcingulate, right secondary sensory, right supplementary motor, and insular cortices, the right thalamus and left caudate nucleus. In contrast, utilizing AT only activation of left insular and supplementary motor cortices was revealed. The paired t-test revealed pain-related activation in the midcingulate, posterior cingulate and left anterior insular cortices for the condition without AT, and activation in the left ventrolateral prefrontal cortex under AT. Activation of the posterior cingulate cortex and thalamus correlated with the amplitude of electrical stimulation. This study revealed an effect on cerebral pain processing while performing AT. This might represent the cerebral correlate of different painful stimulus processing by subjects who are trained in performing relaxation techniques. However, due to the absence of a control group, further studies are needed to confirm this theory. © 2012 European Federation of International Association for the Study of Pain Chapters.

Differential effects of subcutaneous electrical stimulation (SQS) and transcutaneous electrical nerve stimulation (TENS) in rodent models of chronic neuropathic or inflammatory pain.

PubMed

Vera-Portocarrero, Louis P; Cordero, Toni; Billstrom, Tina; Swearingen, Kim; Wacnik, Paul W; Johanek, Lisa M

2013-01-01

Electrical stimulation has been used for many years for the treatment of pain. Present-day research demonstrates that stimulation targets and parameters impact the induction of specific pain-modulating mechanisms. New targets are increasingly being investigated clinically, but the scientific rationale for a particular target is often not well established. This present study compares the behavioral effects of targeting peripheral axons by electrode placement in the subcutaneous space vs. electrode placement on the surface of the skin in a rodent model. Rodent models of inflammatory and neuropathic pain were used to investigate subcutaneous electrical stimulation (SQS) vs. transcutaneous electrical nerve stimulation (TENS). Electrical parameters and relative location of the leads were held constant under each condition. SQS had cumulative antihypersensitivity effects in both inflammatory and neuropathic pain rodent models, with significant inhibition of mechanical hypersensitivity observed on days 3-4 of treatment. In contrast, reduction of thermal hyperalgesia in the inflammatory model was observed during the first four days of treatment with SQS, and reduction of cold allodynia in the neuropathic pain model was seen only on the first day with SQS. TENS was effective in the inflammation model, and in agreement with previous studies, tolerance developed to the antihypersensitivity effects of TENS. With the exception of a reversal of cold hypersensitivity on day 1 of testing, TENS did not reveal significant analgesic effects in the neuropathic pain rodent model. The results presented show that TENS and SQS have different effects that could point to unique biologic mechanisms underlying the analgesic effect of each therapy. Furthermore, this study is the first to demonstrate in an animal model that SQS attenuates neuropathic and inflammatory-induced pain behaviors. © 2013 Medtronic, Inc.

Electrical stimulation of the insular cortex as a novel target for the relief of refractory pain: An experimental approach in rodents.

PubMed

Dimov, Luiz Fabio; Toniolo, Elaine Flamia; Alonso-Matielo, Heloísa; de Andrade, Daniel Ciampi; Garcia-Larrea, Luis; Ballester, Gerson; Teixeira, Manoel Jacobsen; Dale, Camila Squarzoni

2018-07-02

Cortical electrical stimulation (CES) has shown to be an effective therapeutic alternative for neuropathic pain refractory to pharmacological treatment. The primary motor cortex(M1) was the main cortical target used in the vast majority of both invasive and non-invasive studies. Despite positive results M1-based approaches still fail to relieve pain in a significant proportion of individuals. It has been advocated that the direct stimulation of cortical areas directly implicated in the central integration of pain could increase the efficacy of analgesic brain stimulation. Here, we evaluated the behavioral effects of electrical stimulation of the insular cortex (ESI) on pain sensitivity in an experimental rat model of peripheral neuropathy, and have described the pathways involved. Animals underwent chronic constriction of the sciatic nerve in the right hind limb and had concentric electrodes implanted in the posterior dysranular insular cortex. Mechanical nociception responses were evaluated before and at the end of a 15-min session of ESI (60Hz, 210μs, 1V). ESI reversed mechanical hypersensitivity in the paw contralateral to the brain hemisphere stimulated, without inducing motor impairment in the open-field test. Pharmacological blockade of μ-opioid (MOR) or type 1-cannabinoid receptors (CB1R) abolished ESI-induced antinociceptive effects. Evaluation of CB1R and MOR spatial expression demonstrated differential modulation of CB1R and MOR in the periaqueductal gray matter (PAG) of ESI-treated rats in sub-areas involved in pain processing/modulation. These results indicate that ESI induces antinociception by functionally modulating opioid and cannabinoid systems in the PAG pain circuitry in rats with experimentally induced neuropathic pain. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficacy of Percutaneous Electrical Nerve Stimulation and Therapeutic Exercise for Older Adults with Chronic Low Back Pain: A Randomized Controlled Trial

PubMed Central

Weiner, Debra K.; Perera, Subashan; Rudy, Thomas E.; Glick, Ronald M.; Shenoy, Sonali; Delitto, Anthony

2008-01-01

Chronic low back pain (CLBP) in older adults may be disabling and therapeutically challenging, largely because of the inefficacy and/or morbidity associated with traditional pain treatment. We conducted a randomized controlled trial in 200 men and women ≥ age 65 with CLBP to evaluate the efficacy of percutaneous electrical nerve stimulation (PENS) with and without general conditioning and aerobic exercise (GCAE), for reducing pain and improving physical function. Participants were randomized to receive 1) PENS, 2) control-PENS (brief electrical stimulation to control for treatment expectancy), 3) PENS + GCAE, or 4) control-PENS + GCAE, twice a week for 6 weeks. All four groups experienced significantly reduced pain (range −2.3 to −4.1 on the McGill Pain Questionnaire short form), improved self-reported disability (range −2.1 to −3.0 on Roland scale) and improved gait velocity (0.04–0.07 m/sec), sustained at 6 months. The GCAE groups experienced significantly fewer fear avoidance beliefs immediately post-intervention and at 6 months than non-GCAE groups. There were no significant side effects. Since brief electrical stimulation (i.e., control-PENS) facilitated comparably reduced pain and improved function at 6 months as compared with PENS, the exact dose of electrical stimulation required for analgesia cannot be determined. GCAE was more effective than PENS alone in reducing fear avoidance beliefs, but not in reducing pain or improving physical function. PMID:18930352

Reduction of chronic abdominal pain in patients with inflammatory bowel disease through transcranial direct current stimulation: a randomized controlled trial.

PubMed

Volz, Magdalena S; Farmer, Annabelle; Siegmund, Britta

2016-02-01

Inflammatory bowel disease (IBD) is frequently associated with chronic abdominal pain (CAP). Transcranial direct current stimulation (tDCS) has been proven to reduce chronic pain. This study aimed to investigate the effects of tDCS in patients with CAP due to IBD. This randomized, sham-controlled, double blind, parallel-designed study included 20 patients with either Crohn disease or ulcerative colitis with CAP (≥3/10 on the visual analog scale (VAS) in 3/6 months). Anodal or sham tDCS was applied over the primary motor cortex for 5 consecutive days (2 mA, 20 minutes). Assessments included VAS, pressure pain threshold, inflammatory markers, and questionnaires on quality of life, functional and disease specific symptoms (Irritable Bowel Syndrome-Severity Scoring System [IBS-SSS]), disease activity, and pain catastrophizing. Follow-up data were collected 1 week after the end of the stimulation. Statistical analyses were performed using analysis of variance and t tests. There was a significant reduction of abdominal pain in the anodal tDCS group compared with sham tDCS. This effect was evident in changes in VAS and pressure pain threshold on the left and right sides of the abdomen. In addition, 1 week after stimulation, pain reduction remained significantly decreased in the right side of the abdomen. There was also a significant reduction in scores on pain catastrophizing and on IBS-SSS when comparing both groups. Inflammatory markers and disease activity did not differ significantly between groups throughout the experiment. Transcranial direct current stimulation proved to be an effective and clinically relevant therapeutic strategy for CAP in IBD. The analgesic effects observed are unrelated to inflammation and disease activity, which emphasizes central pain mechanisms in CAP.

Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

PubMed Central

Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone

2018-01-01

The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1’s role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual’s first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and ‘SHAM-VL’), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here. PMID:29630681

Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

PubMed

Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone; Weissman-Fogel, Irit

2018-01-01

The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1's role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual's first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and 'SHAM-VL'), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here.

Effectiveness of Physiotherapy and GaAlAs Laser in the Management of Temporomandibular Joint Disorders

PubMed Central

Hlinakova, Petra; Kasparova, Magdalena; Rehacek, Adam; Vavrickova, Lenka; Navrátil, Leoš

2012-01-01

Abstract Objective: Low-level laser therapy (LLLT) is a treatment method commonly used in physiotherapy for musculoskeletal disorders. The aim of this study was to monitor the function of temporomandibular joint (TMJ) and surrounding tissues and compare the objective measurements of the effect of LLLT. Background data: LLLT has been considered effective in reducing pain and muscular tension; thus improving the quality of patients' lives. Materials and Methods: TMJ function was evaluated by cephalometric tracing analysis, orthopantomogram, TMJ tomogram, and computer face-bow record. Interalveolar space between central incisors before and after therapy was measured. Patients evaluated pain on the Visual Analog Scale. LLLT was performed in five treatment sessions (energy density of 15.4 J/cm2) by semiconductive GaAlAs laser with an output of 280 mW, emitting radiation wavelength of 830 mm. The laser supplied a spot of∼0.2 cm2. Results: Baseline comparisons between the healthy patients and patients with low-level laser application show that TMJ pain during function is based on anatomical and function changes in TMJ areas. Significant differences were seen in the posterior and anterior face height. The results comparing healthy and impaired TMJ sagittal condyle paths showed that patients with TMJ pain during function had significantly flatter nonanatomical movement during function. After therapy, the unpleasant feeling was reduced from 27.5 to 4.16 on the pain Visual Analog Scale. The pain had reduced the ability to open the mouth from 34 to 42 mm. Conclusions: The laser therapy was effective in the improvement of the range of temporomandibular disorders (TMD) and promoted a significant reduction of pain symptoms. PMID:22551049

A split face study to document the safety and efficacy of clearance of melasma with a 5 ns q switched Nd YAG laser versus a 50 ns q switched Nd YAG laser.

PubMed

Alsaad, Salman M S; Ross, E Victor; Mishra, Vineet; Miller, Lee

2014-12-01

To determine the safety and efficacy of a 50 ns Q switched Nd YAG laser vs. a 5 ns Q switched Nd YAG laser for clearance of melasma. To compare subject satisfaction, efficacy, and comfort level between the two lasers. This is a prospective, randomized split face clinical study. The study was approved by the Scripps IRB. Ten healthy female subjects with moderate to severe melasma were enrolled. Each subject had three laser treatments one month apart. Patients were followed up approximately 1 month, 3 months, and 6 months after the final laser treatment. A treatment session consisted of a microdermabrasion, 1064 nm QS laser, and topicals. Subjects were asked to rate treatment pain based on a numerical scale range 0-10 (0 = no pain and 10 = worst pain). A melasma area and severity index (MASI) grading system was applied. Also, melanin measurements were acquired by a reflectance spectrophotometer. Side effects were documented during the study including post treatment erythema. Eight patients completed the study. Subjects showed improvement on both sides of the face. From baseline to 1 month post the final laser treatment, the average MASI scores showed a 16% reduction for the 50 ns QS 1064 nm laser vs. a 27% reduction for the 5 ns QS 1064 nm laser (both significant versus baseline pigment, P < 0.05). This difference in MASI scores between the two lasers was not statistically significant (P = 0.87930). Laser treatments displayed mild erythema that resolved after one day. The melanin meter measurements showed a reduction in pigment readings on both sides. Three months after the final treatment there was some relapse in the melasma, as the mean pigment reduction fell to 12% for the 50 ns laser and 11% for the 5 ns laser. By 3 months pigment reduction was not statistically significant for either laser, and no significant differences in pigment reduction were noted between the two pulse durations. There was a statistically significant difference (P < 0.05) in pain scores reported by the subjects (scale 0-10), the mean pain score for 50 ns QS 1064 nm laser was 1.2 and for the 5 ns QS 2.9 the score was 2.9. In this study, we showed that a combination of microdermabrasion, QS1064 nm laser, and topicals decreased the MASI and meter scores without clinically significant side effects. Moreover, the longer pulsed Q switched 1064 nm laser i.e. (50 ns) was associated with less pain than its shorter pulse width counterpart. © 2014 Wiley Periodicals, Inc.

Laser-evoked potentials mediated by mechano-insensitive nociceptors in human skin.

PubMed

Dusch, M; van der Ham, J; Weinkauf, B; Benrath, J; Rukwied, R; Ringkamp, M; Schmelz, M; Treede, R-D; Baumgärtner, U

2016-05-01

Laser-evoked potentials (LEP) were assessed after peripheral nerve block of the lateral femoral cutaneous nerve (LFCN) in healthy volunteers from partially anesthetized skin areas to differentially stimulate mechano-insensitive nociceptors. An ultrasound-guided nerve block of the LFCN was performed in 12 healthy male subjects with Ropivacain 1%. After 30 min, the nerve block induced significantly larger anesthetic areas to mechanical stimuli than to electrical stimuli revealing an area of differential sensitivity. LEPs, reaction times and pain ratings were recorded in response to the laser stimuli of (1) completely anesthetic skin, (2) mechano-insensitive, but electrically excitable skin ('differential sensitivity'), (3) normal skin. LEP latencies in the area of differential sensitivity were increased compared to unaffected skin (228 ± 8.5 ms, vs. 181 ± 3.6 ms, p < 0.01) and LEP amplitudes were reduced (14.8 ± 1.2 μV vs. 24.6 ± 1.7 μV, p < 0.01). Correspondingly, psychophysically assessed response latencies in the differentially anesthetic skin were increased (649 ms vs. 427 ms, p < 0.01) and pain ratings reduced (1.5/10 vs. 5/10 NRS, p < 0.01). The increase in LEP latency suggests that mechano-insensitive heat-sensitive Aδ nociceptors (MIA, type II) have a slower conduction velocity or higher utilization time than mechano-sensitive type II Aδ nociceptors. Moreover, widely branched, slowly conducting and mechano-insensitive branches of Aδ nociceptors can explain our finding. LEPs in the differentially anesthetized skin provide specific information about a mechanically insensitive but heat-sensitive subpopulation of Aδ nociceptors. These findings support the concept that A-fibre nociceptors exhibit a similar degree of modality specificity as C-fibre nociceptors. © 2015 European Pain Federation - EFIC®

Efficacy of Diode Laser for the Management of Potentially Malignant Disorders.

PubMed

Reddy Kundoor, Vinay Kumar; Patimeedi, Ashwini; Roohi, Shameena; Maloth, Kotya Naik; Kesidi, Sunitha; Masabattula, Geetha Kumari

2015-01-01

Laser dentistry is a one of the upcoming advanced treatment modality for oral mucosal lesions. Diode laser is a soft tissue laser that has found much acceptance in all branches of dentistry. Available compact size and feasibility has render diode laser an enhanced tool for today's clinical practice. The aim of this study is to determine the efficacy and safety of diode laser for the management of white lesions such as oral leukoplakia (OL) and oral lichen planus (OLP). The study was conducted by using diode laser 980 nm on 10 patients with white lesions (5 OL and 5 OLP) aged between 35 to 65 years. Of the 10 patients (5 OL and 5 OLP), 3 patients (30%) complained of moderate pain and 7 patients (70%) complained of mild pain, for first 3 days after laser irradiation, and pain disappeared at end of first week. There was no recurrence of the lesion during the 6-month follow up. Diode lasers provide acceptable clinical improvement of potentially malignant lesions with minimal side effects. It can be considered one of the best alternative treatment modality for oral mucosal lesions.

[Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

PubMed

Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

2017-06-25

Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

Laser Therapy and Pain-Related Behavior after Injury of the Inferior Alveolar Nerve: Possible Involvement of Neurotrophins

PubMed Central

de Oliveira Martins, Daniel; Martinez dos Santos, Fabio; Evany de Oliveira, Mara; de Britto, Luiz R.G.; Benedito Dias Lemos, José

2013-01-01

Abstract Nerve-related complications have been frequently reported in dental procedures, and a very frequent type of occurrence involves the inferior alveolar nerve (IAN). The nerve injury in humans often results in persistent pain accompanied by allodynia and hyperalgesia. In this investigation, we used an experimental IAN injury in rats, which was induced by a Crile hemostatic clamp, to evaluate the effects of laser therapy on nerve repair. We also studied the nociceptive behavior (von Frey hair test) before and after the injury and the behavioral effects of treatment with laser therapy (emitting a wavelength of 904 nm, output power of 70 Wpk, a spot area of ∼0.1 cm2, frequency of 9500 Hz, pulse time 60 ns and an energy density of 6 J/cm2). As neurotrophins are essential for the process of nerve regeneration, we used immunoblotting techniques to preliminarily examine the effects of laser therapy on the expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). The injured animals treated with laser exhibited an improved nociceptive behavior. In irradiated animals, there was an enhanced expression of NGF (53%) and a decreased BDNF expression (40%) after laser therapy. These results indicate that BDNF plays a locally crucial role in pain-related behavior development after IAN injury, increasing after lesions (in parallel to the installation of pain behavior) and decreasing with laser therapy (in parallel to the improvement of pain behavior). On the other hand, NGF probably contributes to the repair of nerve tissue, in addition to improving the pain-related behavior. PMID:23190308

A randomized placebo-blind study of the effect of low power laser on pain caused by irreversible pulpitis.

PubMed

Ramalho, Karen Müller; de Souza, Lárissa Marcondes Paladini; Tortamano, Isabel Peixoto; Adde, Carlos Alberto; Rocha, Rodney Garcia; de Paula Eduardo, Carlos

2016-12-01

This randomized placebo-blind study aimed to evaluate the effect of laser phototherapy (LPT) on pain caused by symptomatic irreversible pulpitis (SIP). Sixty patients diagnosed with SIP were randomly assigned to treatment groups (n = 15): G1 (control), G2 (laser placebo-sham irradiation), G3 (laser irradiation at 780 nm, 40 mW, 4 J/cm 2 ), and G4 (laser irradiation at 780 nm, 40 mW, 40 J/cm 2 ). Spontaneous pain was recorded using a VAS score before (T0), immediately after (T1), and 15 min after treatment (T2). Local anesthetics failure during emergency endodontic treatment was also assessed. There was no pain difference in T1 and T2 between the experimental laser groups (G3 and G4) and the placebo group (G2). The 4-J/cm 2 (G3) irradiation resulted in significant increase in the local anesthetics failure in lower jar teeth. This effect could be suggested as consequence of the LPT improvement in local circulation and vasodilatation that would result in the increase of local anesthetic agent absorption. The application of 780-nm diode laser irradiation, at 4 and 40 J/cm 2 , showed no effect in reducing the pain in SIP in comparison to the placebo group. The fluence of 4 J/cm 2 showed a negative effect in local anesthetics, resulting in significant increase of complimentary local anesthesia during emergency endodontic treatment. This work provides evidence of the consequence of LPT application on teeth with symptomatic irreversible pulpitis. LPT should be avoided in teeth with pain due to irreversible pulpitis.

Subcutaneous peripheral nerve stimulation with inter-lead stimulation for axial neck and low back pain: case series and review of the literature.

PubMed

Burgher, Abram H; Huntoon, Marc A; Turley, Todd W; Doust, Matthew W; Stearns, Lisa J

2012-01-01

While pain in the extremities often responds to treatment using spinal cord stimulation (SCS), axial pain is notoriously refractory to SCS. Interest in subcutaneous peripheral nerve stimulation (SQ PNS) as an alternative to SCS has emerged, but the most appropriate electrode locations and neurostimulator programming techniques are not yet clear. A retrospective review was conducted of consecutive patients evaluated from August 2009 to December 2010 who had undergone trial of SQ PNS with inter-lead stimulation for axial spine pain. Patients proceeding to implant were followed postoperatively with routine clinical visits and a survey form at last follow-up. Ultrasound was used intraoperatively to ensure placement of electrodes at the appropriate depth in patients with larger body mass index. Primary outcome was patient-reported pain relief at last follow-up. Literature review was conducted by searching MEDLINE (1948-present) and through an unstructured review by the authors. Ten patients underwent trial of SQ PNS and six proceeded to permanent implantation. Fifty percent (3/6) of implanted patients preferred neurostimulation programming that included inter-lead stimulation ("cross-talk"). Average duration of postoperative follow-up was 4.5 months (range 2-9 months). Average patient-reported pain relief at last follow-up was 45% (range 20-80%). One patient required re-operation for migration. Patients not proceeding to implant had paresthesia coverage but no analgesia. SQ PNS is a promising therapy for axial neck and back pain based on a small cohort of patients. Ultrasound was useful to assist with electrode placement at the most appropriate depth beneath the skin. While inter-lead stimulation has been preferred by patients in published reports, we did not find it clearly influenced pain relief. Future investigations should include a randomized, controlled study design, as well as defined implantation technique and neurostimulator programming algorithms. © 2011 International Neuromodulation Society.

Nonlinear Inverted-U Shaped Relationship between Aging and Epidermal Innervation in the Rat Plantar Hind Paw: a Laser Scanning Confocal Microscopy Study.

PubMed

Kaliappan, Sankaranarayanan; Simone, Donald A; Banik, Ratan K

2018-04-13

The under-reporting of pain and atypical manifestations of painful syndromes within the elderly population have been well-documented, however, the specific relationship between pain and aging remains ambiguous. Previous studies have reported degenerative changes in primary afferents with aging. In this study, we questioned whether there is any change in the density of primary afferent endings within the epidermis of aged animals. Rats were categorically assessed in four age groups, each representing a key developmental stage across their life span: juvenile (2 months); adult (7 months); aged (18 months); and senescent (24-26 months). The plantar hind paw skin was removed, post-fixed, cut, and immunostained for protein gene product 9.5 and type IV collagen. Rats in the adult aged groups had significantly increased epidermal nerve densities and total lengths of immunoreactive nerve fibers, compared to both juvenile and senescent rats. However, the paw withdrawal thresholds to punctate mechanical stimulation progressively increased with age, and did not exhibit a clear relationship with epidermal innervation. We conclude a non-linear, inverted-U shaped relationship between rat plantar epidermal nerve density with aging, which does not correlate with mechanically-induced paw withdrawal behaviors. This article presents age-related decreased epidermal innervation in rat hind paw skin, which partly explains mechanisms underlying decreased pain sensitivity in aged subjects. The article may help clinicians to understand that any compromise of pain-sensing pathway can lead to under-reporting of pain, inadequate analgesia, and slower recovery from a painful condition. Copyright © 2018. Published by Elsevier Inc.

Augmented Central Pain Processing in Vulvodynia

PubMed Central

Hampson, Johnson P.; Reed, Barbara D.; Clauw, Daniel J.; Bhavsar, Rupal; Gracely, Richard H.; Haefner, Hope K.; Harris, Richard E.

2013-01-01

Vulvodynia (VVD) is a chronic pain disorder, wherein women display sensitivity to evoked stimuli at the vulva and/or spontaneous vulvar pain. Our previous work suggests generalized hyperalgesia in this population, however little is known about central neurobiological factors that may influence pain in VVD. Here we investigated local (vulvar) and remote (thumb) pressure evoked pain processing in 24 VVD patients compared to 13 age-matched, pain-free healthy controls (HC). As a positive control we also examined thumb pressure pain in 24 fibromyalgia (FM) patients. The VVD and FM patients displayed overlapping insular brain activations that were greater than HC, in response to thumb stimulation (P<0.005 corrected). Compared to HC, VVD participants displayed greater levels of activation during thumb stimulation within the insula, dorsal mid-cingulate, posterior cingulate and thalamus (P<0.005 corrected). Significant differences between VVD subgroups (primary versus secondary and provoked versus unprovoked) were seen within the posterior cingulate with thumb stimulation, and within the precuneus region with vulvar stimulation (provoked versus unprovoked only). The augmented brain activation in VVD patients in response to a stimulus remote from the vulva suggests central neural pathology in this disorder. Moreover, differing central activity between VVD subgroups suggests heterogeneous pathologies within this diagnosis. PMID:23578957

Psychotherapy With Somatosensory Stimulation for Endometriosis-Associated Pain: A Randomized Controlled Trial.

PubMed

Meissner, Karin; Schweizer-Arau, Annemarie; Limmer, Anna; Preibisch, Christine; Popovici, Roxana M; Lange, Isabel; de Oriol, Barbara; Beissner, Florian

2016-11-01

To evaluate whether psychotherapy with somatosensory stimulation is effective for the treatment of pain and quality of life in patients with endometriosis-related pain. Patients with a history of endometriosis and chronic pelvic pain were randomized to either psychotherapy with somatosensory stimulation (ie, different techniques of acupuncture point stimulation) or wait-list control for 3 months, after which all patients were treated. The primary outcome was brain connectivity assessed by functional magnetic resonance imaging. Prespecified secondary outcomes included pain on 11-point numeric rating scales (maximal and average global pain, pelvic pain, dyschezia, and dyspareunia) and physical and mental quality of life. A sample size of 30 per group was planned to compare outcomes in the treatment group and the wait-list control group. From March 2010 through March 2012, 67 women (mean age 35.6 years) were randomly allocated to intervention (n=35) or wait-list control (n=32). In comparison with wait-list controls, treated patients showed improvements after 3 months in maximal global pain (mean group difference -2.1, 95% confidence interval [CI] -3.4 to -0.8; P=.002), average global pain (-2.5, 95% CI -3.5 to -1.4; P<.001), pelvic pain (-1.4, 95% CI -2.7 to -0.1; P=.036), dyschezia (-3.5, 95% CI -5.8 to -1.3; P=.003), physical quality of life (3.8, 95% CI 0.5-7.1, P=.026), and mental quality of life (5.9, 95% CI 0.6-11.3; P=.031); dyspareunia improved nonsignificantly (-1.8, 95% CI -4.4 to 0.7; P=.150). Improvements in the intervention group remained stable at 6 and 24 months, and control patients showed comparable symptom relief after delayed intervention. Psychotherapy with somatosensory stimulation reduced global pain, pelvic pain, and dyschezia and improved quality of life in patients with endometriosis. After 6 and 24 months, when all patients were treated, both groups showed stable improvements. ClinicalTrials.gov, https://clinicaltrials.gov, NCT01321840.

Occipital Nerve Field Transcranial Direct Current Stimulation Normalizes Imbalance Between Pain Detecting and Pain Inhibitory Pathways in Fibromyalgia.

PubMed

De Ridder, Dirk; Vanneste, Sven

2017-04-01

Occipital nerve field (OCF) stimulation with subcutaneously implanted electrodes is used to treat headaches, more generalized pain, and even failed back surgery syndrome via unknown mechanisms. Transcranial direct current stimulation (tDCS) can predict the efficacy of implanted electrodes. The purpose of this study is to unravel the neural mechanisms involved in global pain suppression, mediated by occipital nerve field stimulation, within the realm of fibromyalgia. Nineteen patients with fibromyalgia underwent a placebo-controlled OCF tDCS. Electroencephalograms were recorded at baseline after active and sham stimulation. In comparison with healthy controls, patients with fibromyalgia demonstrate increased dorsal anterior cingulate cortex, increased premotor/dorsolateral prefrontal cortex activity, and an imbalance between pain-detecting dorsal anterior cingulate cortex and pain-suppressing pregenual anterior cingulate cortex activity, which is normalized after active tDCS but not sham stimulation associated with increased pregenual anterior cingulate cortex activation. The imbalance improvement between the pregenual anterior cingulate cortex and the dorsal anterior cingulate cortex is related to clinical changes. An imbalance assumes these areas communicate and, indeed, abnormal functional connectivity between the dorsal anterior cingulate cortex and pregenual anterior cingulate cortex is noted to be caused by a dysfunctional effective connectivity from the pregenual anterior cingulate cortex to the dorsal anterior cingulate cortex, which improves and normalizes after real tDCS but not sham tDCS. In conclusion, OCF tDCS exerts its effect via activation of the descending pain inhibitory pathway and de-activation of the salience network, both of which are abnormal in fibromyalgia.

Effect of single-dose low-level helium-neon laser irradiation on orthodontic pain: a split-mouth single-blind placebo-controlled randomized clinical trial.

PubMed

Sobouti, Farhad; Khatami, Maziar; Chiniforush, Nasim; Rakhshan, Vahid; Shariati, Mahsa

2015-01-01

Pain is the most common complication of orthodontic treatment. Low-level laser therapy (LLLT) has been suggested as a new analgesic treatment free of the adverse effects of analgesic medications. However, it is not studied thoroughly, and the available studies are quite controversial. Moreover, helium neon (He-Ne) laser has not been assessed before. This split-mouth placebo-controlled randomized clinical trial was performed on 16 male and 14 female orthodontic patients requiring bilateral upper canine retraction. The study was performed at a private clinic in Sari, Iran, in 2014. It was single blind: patients, orthodontist, and personnel were blinded of the allocations, but the laser operator (periodontist) was not blinded. Once canine retractor was activated, a randomly selected maxillary quarter received a single dose of He-Ne laser irradiation (632.8 nm, 10 mw, 6 j/cm(2) density). The other quarter served as the placebo side, treated by the same device but powered off. In the first, second, fourth, and seventh days, blinded patients rated their pain sensed on each side at home using visual analog scale (VAS) questionnaires. There was no harm identified during or after the study. Pain changes were analyzed using two- and one-way repeated-measures ANOVA, Bonferroni, and t-test (α = 0.01, β > 0.99). This trial was not registered. It was self-funded by the authors. Sixteen males and 11 females remained in the study (aged 12-21). Average pain scores sensed in all 4 intervals on control and laser sides were 4.06 ± 2.85 and 2.35 ± 1.77, respectively (t-test P < 0.0001). One-way ANOVA showed significant pain declines over time, in each group (P < 0.0001). Two-way ANOVA showed significant effects for LLLT (P < 0.0001) and time (P = <0.0001). Single-dose He-Ne laser therapy might reduce orthodontic pain caused by retracting maxillary canines.

Spinal cord stimulation during the antepartum and intrapartum periods: a case report showing no deleterious effect of conventional paraesthesia producing stimulation.

PubMed

Moussa, Ahmad Abdelhai; Glancz, Laurence; Das, Mausumi; Basu, Surajit

2016-12-01

We report on a 25-year-old woman who used her spinal cord stimulator (SCS), previously inserted for chronic regional pain syndrome (CPRS), to assist with both chronic and pregnancy-related pain management. We describe the therapeutic effect of the stimulator and briefly highlight the issues surrounding the use of SCS during pregnancy.

An Electrical Muscle Stimulation Suit for Increasing Blood Pressure

DTIC Science & Technology

2008-09-01

an exploratory way in about 100 trials. Maximal indi- vidual stimulation intensity was selected to give a solid, tetanic muscle contraction without...therapy and in muscle strength training in athletes. However, if the electrical stimulation is too intense, the result will be muscle contraction pain...Each subject was instructed to have the investigator lower the intensity or stop the stimulation if muscle contraction pain was experienced

Optoacoustic effect is responsible for laser-induced cochlear responses

NASA Astrophysics Data System (ADS)

Kallweit, N.; Baumhoff, P.; Krueger, A.; Tinne, N.; Kral, A.; Ripken, T.; Maier, H.

2016-06-01

Optical stimulation of the cochlea with laser light has been suggested as an alternative to conventional treatment of sensorineural hearing loss with cochlear implants. The underlying mechanisms are controversially discussed: The stimulation can either be based on a direct excitation of neurons, or it is a result of an optoacoustic pressure wave acting on the basilar membrane. Animal studies comparing the intra-cochlear optical stimulation of hearing and deafened guinea pigs have indicated that the stimulation requires intact hair cells. Therefore, optoacoustic stimulation seems to be the underlying mechanism. The present study investigates optoacoustic characteristics using pulsed laser stimulation for in vivo experiments on hearing guinea pigs and pressure measurements in water. As a result, in vivo as well as pressure measurements showed corresponding signal shapes. The amplitude of the signal for both measurements depended on the absorption coefficient and on the maximum of the first time-derivative of laser pulse power (velocity of heat deposition). In conclusion, the pressure measurements directly demonstrated that laser light generates acoustic waves, with amplitudes suitable for stimulating the (partially) intact cochlea. These findings corroborate optoacoustic as the basic mechanism of optical intra-cochlear stimulation.

Analgesia Is Enhanced by Providing Information regarding Good Outcomes Associated with an Odor: Placebo Effects in Aromatherapy?

PubMed Central

Masaoka, Yuri; Kawase, Akiko; Homma, Ikuo

2013-01-01

No previous report has described whether information regarding an odor used in aromatherapy has placebo effects. We investigated whether placebo analgesia was engendered by verbal information regarding the analgesic effects of an odor. Twelve of 24 subjects were provided with the information that a lavender odor would reduce pain (informed), whereas the other 12 subjects were not (not-informed). Concurrent with respiration recording, the subjects were administered a lavender-odor or no-odor treatment during application of painful stimulation to the forefinger. The subjects reported their experience of pain and its unpleasantness on a visual analogue scale after the painful stimulation. The lavender-odor treatment significantly alleviated pain and unpleasantness compared with the no-odor treatment in the informed (P < 0.01) and not-informed groups (P < 0.05). The no-odor treatment in the informed group significantly alleviated pain and unpleasantness compared with both the no-odor and lavender-odor treatments in the not-informed group (P < 0.05). Rapid and shallow breathing induced by the painful stimulation became slow and deep during the lavender-odor and no-odor treatments in both groups. Information regarding a lavender odor, the lavender odor itself, and slower breathing contributed to reduced perceptions of pain and unpleasantness during painful stimulation, suggesting that placebo effects significantly contribute to analgesia in aromatherapy. PMID:23840270

Central noradrenergic mechanisms and the acute stress response during painful stimulation.

PubMed

Chapman, C Richard; Bradshaw, David H; Donaldson, Gary W; Jacobson, Robert C; Nakamura, Yoshio

2014-12-01

Events that threaten tissue integrity including noxious stimulation activate central noradrenergic circuits, particularly locus coeruleus and its projections. Recent advances in theory hold that an adaptive, defensive shift in brain activity takes place in response to threat. In principle, this shift may accentuate the autonomic and central biomarkers of the perception of painful events and the experience of pain itself. We have examined the effects of an alpha-2 agonist on pupil dilation responses, skin conductance responses, near field somatosensory evoked potentials and pain reports in normal volunteers undergoing repeated trials of painful fingertip stimulation delivered at low, medium and high intensities. In a double-blinded study, 114 healthy male and female volunteers underwent repeated noxious stimulation under baseline, placebo and active drug conditions where the active drug was the alpha-2 agonist tizanidine 4 mg. In contrast to baseline and placebo conditions, tizanidine 4 mg significantly reduced the magnitudes of the mean pupil dilation response, the mean skin conductance response, the mean near field somatosensory evoked potential peak-to-peak amplitude and the mean pain intensity rating. Stimulus intensity significantly altered all three biomarkers and the pain report in a graded fashion. There were no sex differences. These findings support the hypotheses that painful events activate central noradrenergic circuits, and that these circuits play a role in the autonomic and central arousal associated with pain. © The Author(s) 2014.

The short- and long-term benefit in chronic low back pain through adjuvant electrical versus manual auricular acupuncture.

PubMed

Sator-Katzenschlager, Sabine M; Scharbert, Gisela; Kozek-Langenecker, Sibylle A; Szeles, Jozef C; Finster, Gabriele; Schiesser, Andreas W; Heinze, Georg; Kress, Hans Georg

2004-05-01

Acupuncture is an established adjuvant analgesic modality for the treatment of chronic pain. Electrical stimulation of acupuncture points is considered to increase acupuncture analgesia. In this prospective, randomized, double-blind, controlled study we tested the hypothesis that auricular electroacupuncture (EA) relieves pain more effectively than conventional manual auricular acupuncture (CO) in chronic low back pain patients with insufficient pain relief (visual analogue scale [VAS] > or = 5) treated with standardized analgesic therapy. Disposable acupuncture needles were inserted in the auricular acupuncture points 29, 40, and 55 of the dominant side and connected to a newly developed battery-powered miniaturized stimulator worn behind the ear. Patients were randomized into group EA (n = 31) with continuous low-frequency auricular EA (1 Hz biphasic constant current of 2 mA) and group CO (n = 30) without electrical stimulation (sham-electroacupuncture). Treatment was performed once weekly for 6 wk, and in each group needles were withdrawn 48 h after insertion. During the study period and a 3-mo follow-up, patients were asked to complete the McGill questionnaire. Psychological well being, activity level, quality of sleep, and pain intensity were assessed by means of VAS; moreover, analgesic drug consumption was documented. Pain relief was significantly better in group EA during the study and the follow-up period as compared with group CO. Similarly, psychological well-being, activity, and sleep were significantly improved in group EA versus group CO, the consumption of analgesic rescue medication was less, and more patients returned to full-time employment. Neuropathic pain in particular improved in patients treated with EA. There were no adverse side effects. These results are the first to demonstrate that continuous EA stimulation of auricular acupuncture points improves the treatment of chronic low back pain in an outpatient population. Continuous electrical stimulation of auricular acupuncture points using the new point stimulation device P-stim significantly decreases pain intensity and improves psychological well-being, activity, and sleep in chronic low back pain patients.

Lasers in Periodontics: Review of Literature

DTIC Science & Technology

2015-06-01

Alex Printed Name Orofacial Pain Fellowship Naval Postgraduate Dental School Program and Program Location Uniformed Services University LASERS IN...PERIODONTICS: REVIEW OF THE LITERATURE By Alex Smith MAJ, DC, USA A thesis submitted to the Faculty of the Orofacial Pain Graduate Program Naval...Department Chair Orofaci I Pain Department Glenn Munro, CAPT, DC, USN Dean, Naval Postgraduate Dental School NAVAL POSTGRADUATE DENTAL SCHOOL BETHESDA

Captured by the pain: pain steady-state evoked potentials are not modulated by selective spatial attention.

PubMed

Blöchl, Maria; Franz, Marcel; Miltner, Wolfgang H R; Weiss, Thomas

2015-04-07

Attention has been shown to affect the neural processing of pain. However, the exact mechanisms underlying this modulation remain unknown. Here, we used a new method called pain steady-state evoked potentials (PSSEPs) to investigate whether selective spatial attention affects EEG responses to tonic painful stimuli. In general, steady-state evoked potentials reflect changes in the EEG spectrum at a certain frequency that correspond to the frequency of a train of applied stimuli. In this study, high intensity transcutaneous electrical stimulation was delivered to both hands simultaneously with 31 Hz and 37 Hz, respectively. Subject׳s attention was directed to one of the two trains of stimulation in order to detect a small gap that was occasionally interspersed into the stimulus trains. Thereby, they had to ignore the stimulation applied to the other hand. Results show that PSSEPs were induced at 31 Hz and 37 Hz at frontal and central electrodes. PSSEPs occurred contralaterally to the respective hand stimulated with that frequency. Surprisingly, the magnitude of PSSEPs was not modulated by spatial attention towards one of the two stimuli. Our results indicate that attention can hardly be shifted between two simultaneously applied tonic painful stimulations. Copyright © 2015 Elsevier B.V. All rights reserved.

An MRI-based leg model used to simulate biomechanical phenomena during cuff algometry: a finite element study.

PubMed

Manafi-Khanian, Bahram; Arendt-Nielsen, Lars; Graven-Nielsen, Thomas

2016-03-01

Cuff pressure stimulation is applicable for assessing deep-tissue pain sensitivity by exciting a variety of deep-tissue nociceptors. In this study, the relative transfer of biomechanical stresses and strains from the cuff via the skin to the muscle and the somatic tissue layers around bones were investigated. Cuff pressure was applied on the lower leg at three different stimulation intensities (mild pressure to pain). Three-dimensional finite element models including bones and three different layers of deep tissues were developed based on magnetic resonance images (MRI). The skin indentation maps at mild pressure, pain threshold, and intense painful stimulations were extracted from MRI and applied to the model. The mean stress under the cuff position around tibia was 4.6, 4.9 and around fibula 14.8, 16.4 times greater than mean stress of muscle surface in the same section at pain threshold and intense painful stimulations, respectively. At the same stimulation intensities, the mean strains around tibia were 36.4, 42.3 % and around fibula 32.9, 35.0 %, respectively, of mean strain on the muscle surface. Assuming strain as the ideal stimulus for nociceptors the results suggest that cuff algometry is less capable to challenge the nociceptors of tissues around bones as compared to more superficially located muscles.

Effects of LLLT for pain: a clinical study on different pain types

NASA Astrophysics Data System (ADS)

Tam, Giuseppe

2002-10-01

Objective: The aim of this clinical study is to determine the efficacy of the JR diode laser 904 nm pulsed on pain reduction therapy. Summary Background Data: With respect to pain, the existence of a filter (Rolando's substantia gelatinosa) in the spinal marrow is fundamental. Opening or closing, this filter is able to block transmission of pain impulses to a higher cerebral center. This is in proportion with the A big fibres and C small fibres. The action of the laser influences this mechanism. Additionally, laser interferes in the cytochines (TNf-α , interleukin-1 and interleukin-6) that drive inflammation in the arthritis and are secreted from CD4 e T cells. Low power density laser increases the endorphin synthesis in the dorsal posterior horn of the spinal cord. Besides, laser causes local vasodilatation of the capillaries and an improved circulation of drainage liquids in interstitial space causing an analgesic effect. Methods: Treatment was carried out on 482 cases and 464 patients (274 women and 190 men) in the period between 1987 and 2000. The patients, whose age ranged from 25 to 70, with a mean age of 45 years, were suffering from rheumatic, degenerative and traumatic pathologies as well as cutaneous ulcers. The majority of the patients had been seen by orthopaedists and rheumatologists and had undergone x-ray, ultrasound scanning, TAC, RM examination. All patients had previously received drug-based treatment and/or physiotherapy with poor results. Two thirds were experiencing acute symptomatic pain, while the others presented a chronic pathology with recurrent crises. We used a pulsed JR diode laser, GaAs 904 nm wavelength. Results: Jn the evaluation of the results the following parameters have been considered: disappearance of spontaneous and induced pain, anatomic and functional evaluation of the joints, muscular growth, verbal rating scales, hand dinamometer, patient's pain diary. Very good results were achieved especially with cases of symptomatic osteoarthritis of the cervical vertebrae, with sport-related injuries, with epicondylitis, tendinitis, periarthritis and neuritis. The total relief of pain was achieved in 82% of acute and 65% ofchronic cases. Conclusions: Treatment with 904 nm JR diode laser interrupts the "circulus vitiosus" ofthe origin of the different pains (neuropathic, metabolic, traumatic, toxic, immune-mediated, ischaemic) and its development. LLLT brings a normal physiological condition back to the tissue, thus myofascial pain relief, decreases tension and substantially reduces the symptoms as well as improves the quality of life of the patients. Our fourteen years of experience indicates that LLLT is a low cost, non-invasive method and easy to be applied.

Neural Activation during Anticipation of Near Pain-Threshold Stimulation among the Pain-Fearful

PubMed Central

Yang, Zhou; Jackson, Todd; Huang, Chengzhi

2016-01-01

Fear of pain (FOP) can increase risk for chronic pain and disability but little is known about corresponding neural responses in anticipation of potential pain. In this study, more (10 women, 6 men) and less (7 women, 6 men) pain-fearful groups underwent whole-brain functional magnetic resonance imaging (fMRI) during anticipation of near pain-threshold stimulation. Groups did not differ in the proportion of stimuli judged to be painful but pain-fearful participants reported significantly more state fear prior to stimulus exposure. Within the entire sample, stronger activation was found in several pain perception regions (e.g., bilateral insula, midcingulate cortex (MCC), thalamus, superior frontal gyrus) and visual areas linked to decoding stimulus valences (inferior orbital cortex) during anticipation of “painful” stimuli. Between groups and correlation analyses indicated pain-fearful participants experienced comparatively more activity in regions implicated in evaluating potential threats and processing negative emotions during anticipation (i.e., MCC, mid occipital cortex, superior temporal pole), though group differences were not apparent in most so-called “pain matrix” regions. In sum, trait- and task-based FOP is associated with enhanced responsiveness in regions involved in threat processing and negative affect during anticipation of potentially painful stimulation. PMID:27489536

Motor Cortex Reorganization and Repetitive Transcranial Magnetic Stimulation for Pain-A Methodological Study.

PubMed

Nurmikko, Turo; MacIver, Kathryn; Bresnahan, Rebecca; Hird, Emily; Nelson, Andrew; Sacco, Paul

2016-10-01

Somatotopic reorganization of primary motor cortex (M1) has been described in several neurological conditions associated with chronic pain. We hypothesized that such reorganization impacts on the mechanisms of M1 stimulation induced analgesia and may either compromise the treatment effect of or provide an alternative target site for repetitive transcranial magnetic stimulation (rTMS). The aim of the study was to compare pain relief following rTMS of the standard motor "hotspot" with that of the reorganized area. We used TMS motor mapping in 30 patients to establish the location of the standard motor "hotspot" (site A) and an alternative site located in the reorganized area (site B), both within M1. Where TMS mapping was not possible (N = 8) we determined the location of the two sites using task-related fMRI. We compared the analgesic effect on neuropathic pain of 5 sessions of navigated rTMS applied over (i) site A, (ii) site B, and (iii) occipital fissure (SHAM stimulation site). Total Pain Relief (TOTPAR) was determined as the difference in average weekly pain scores between baseline and following each rTMS cycle, over three weeks. Data from 27 patients was analyzed. rTMS of sites A and B resulted in greater TOTPAR than that of SHAM. No difference was seen between sites A and B. Responders (≥15% pain relief) were seen in both groups, with partial overlap only. Addition of stimulation over site B improved the responder rate by 58% compared with site A. In an open-label extension study of five sessions of rTMS aimed at the optimized target site, 8/11 responders and 1/12 nonresponders reported pain relief. Cortical reorganization may provide a more effective stimulation target for rTMS in some individuals with neuropathic pain. © 2016 International Neuromodulation Society.

'Virtual lesion' in pain research; a study on magnetic stimulation of the primary motor cortex.

PubMed

Granovsky, Y; Liem, K S; Weissman-Fogel, I; Yarnitsky, D; Chistyakov, A; Sinai, A

2016-02-01

'Virtual lesion' ('VL') is a transient disruption of cortical activity during task performance. It can be induced by single pulses or short trains of transcranial magnetic stimulation (TMS) directed to functionally relevant brain areas. We applied 'VL' methodology of a short train of TMS given on top of experimental tonic pain, expecting to see changes in pain scores. Thirty young healthy subjects (15 women) were assessed with active ('VL') or 'sham' TMS in different sessions, randomly. In each session, 30 sec-long contact heat (47.5 °C, right forearm) was applied stand-alone ('baseline') and with 5 sec-long 10 Hz-TMS over left primary motor cortex (M1) starting at 17 sec of the heat stimulation. Pain scores decreased after 'VL' or 'sham' (p < 0.001). Independently of the type of TMS, pain reduction was stronger in women (p = 0.012). A triple Sex x Stimulation type ('VL' or 'sham') x Condition ('baseline' heat pain vs. heat pain with TMS) interaction (p = 0.027) indicated stronger pain reduction by 'VL' in women (p = 0.008) and not in men (p = 0.78) as compared to 'baseline'. Pain catastrophizing and perceived stress ratings affected the model (p = 0.010 and p < 0.001, respectively), but without sex differences. This study indicates that interactions between cortical excitability of the motor cortex and nociceptive processing may be gender-related. © 2015 European Pain Federation - EFIC®

Managing Pain Caused By Neurological Disease

PubMed Central

Tunks, Eldon

1985-01-01

Stabbing paroxysmal pain due to neurological disease can often be controlled by anticonvulsants, whereas steady burning pain is often responsive to tricyclic antidepressants, and to neuroleptics. Overuse of opiates may actually aggravate the pain, necessitating detoxification. Transcutaneous electrical nerve stimulation is helpful for conditions in which pain is localized, especially if there is a ‘trigger area’ or neuroma, or if paresthesias can be stimulated within the painful area. Local anesthetic injection, possibly with corticosteroid, relieves painful scars and neuromas, neuritis, and tender trigger points. Sympathetic blocks are used for post-herpetic neuralgia and sympathetic dystrophies. Relaxation therapy is a very useful psychological treatment. PMID:21274032

Evaluation of the use of a 940 nm diode laser as an adjunct in flap surgery for treatment of chronic periodontitis

PubMed Central

Lobo, Tanya Marguerite; Pol, Dilip Ganpat

2015-01-01

Background: Lasers have several potential benefits such as antibacterial effect and stimulation of wound healing. In addition, hemostasis and delaying epithelial migration may facilitate the outcome of flap surgery. There is a minimal research and evidence currently available for the optimum method of use of a diode laser in flap surgery and its benefit and safety. Hence, this study aimed to investigate the adjunctive effect of diode laser irradiation in open flap debridement (OFD), while treating chronic periodontitis. Materials and Methods: A total of 30 patients with generalized chronic moderate to severe periodontitis with pocket probing depth (PD) ≥5 mm post - Phase I therapy were selected for a split-mouth study. Flap surgery with adjunctive diode laser irradiation was performed in the test quadrant while routine OFD was done in the control quadrant. Clinical parameters including PD, clinical attachment level, gingival recession, plaque index, gingival index and tooth mobility were recorded at baseline, 3 months and 6 months following treatment. In addition, patients’ rating of procedural pain as well as the development of complications postoperatively was assessed. Results: All clinical parameters significantly improved after therapy without any statistically significant difference between the two groups for any of the parameters. The exception was a significantly greater reduction in gingival inflammation in the laser treated group. The laser treatment was acceptable to the patient and did not cause any complications. Conclusion: The diode laser can be safely and effectively used as an adjunct to the treatment of chronic periodontitis with the advantage of decreased gingival inflammation. PMID:25810592

Treatment of burning mouth syndrome with a low-level energy diode laser.

PubMed

Yang, Hui-Wen; Huang, Yu-Feng

2011-02-01

To test the therapeutic efficacy of low-level energy diode laser on burning mouth syndrome. Burning mouth syndrome is characterized by burning and painful sensations in the mouth, especially the tongue, in the absence of significant mucosal abnormalities. Although burning mouth syndrome is relatively common, little is known regarding its etiology and pathophysiology. As a result, no treatment is effective in all patients. Low-level energy diode laser therapy has been used in a variety of chronic and acute pain conditions, including neck, back and myofascial pain, degenerative osteoarthritis, and headache. A total of 17 patients who had been diagnosed with burning mouth syndrome were treated with an 800-nm wavelength diode laser. A straight handpiece was used with an end of 1-cm diameter with the fiber end standing 4 cm away from the end of handpiece. When the laser was applied, the handpiece directly contacted or was immediately above the symptomatic lingual surface. The output used was 3 W, 50 msec intermittent pulsing, and a frequency of 10 Hz, which was equivalent to an average power of 1.5 W/cm(2) (3 W × 0.05 msec × 10 Hz = 1.5 W/cm(2)). Depending on the involved area, laser was applied to a 1-cm(2) area for 70 sec until all involved area was covered. Overall pain and discomfort were analyzed with a 10-cm visual analogue scale. All patients received diode laser therapy between one and seven times. The average pain score before the treatment was 6.7 (ranging from 2.9 to 9.8). The results showed an average reduction in pain of 47.6% (ranging from 9.3% to 91.8%). The burning sensation remained unchanged for up to 12 months. Low-level energy diode laser may be an effective treatment for burning mouth syndrome.

The effect of repeated laser stimuli to ink-marked skin on skin temperature-recommendations for a safe experimental protocol in humans.

PubMed

Madden, Victoria J; Catley, Mark J; Grabherr, Luzia; Mazzola, Francesca; Shohag, Mohammad; Moseley, G Lorimer

2016-01-01

Background. Nd:YAP laser is widely used to investigate the nociceptive and pain systems, generating perpetual and laser-evoked neurophysiological responses. A major procedural concern for the use of Nd:YAP laser stimuli in experimental research is the risk of skin damage. The absorption of Nd:YAP laser stimuli is greater in darker skin, or in pale skin that has been darkened with ink, prompting some ethics boards to refuse approval to experimenters wishing to track stimulus location by marking the skin with ink. Some research questions, however, require laser stimuli to be delivered at particular locations or within particular zones, a requirement that is very difficult to achieve if marking the skin is not possible. We thoroughly searched the literature for experimental evidence and protocol recommendations for safe delivery of Nd:YAP laser stimuli over marked skin, but found nothing. Methods. We designed an experimental protocol to define safe parameters for the use of Nd:YAP laser stimuli over skin that has been marked with black dots, and used thermal imaging to assess the safety of the procedure at the forearm and the back. Results. Using thermal imaging and repeated laser stimulation to ink-marked skin, we demonstrated that skin temperature did not increase progressively across the course of the experiment, and that the small change in temperature seen at the forearm was reversed during the rest periods between blocks. Furthermore, no participant experienced skin damage due to the procedure. Conclusion. This protocol offers parameters for safe, confident and effective experimentation using repeated Nd:YAP laser on skin marked with ink, thus paving the way for investigations that depend on it.

[Spinal cord stimulation (SCS) as a treatment for the spread phenomenon related to complex regional pain syndrome type- I (CRPS-I )].

PubMed

Goto, Shinichi; Taira, Takaomi; Hori, Tomokatsu

2009-09-01

The authors describe an experience of spinal cord stimulation (SCS) in a 30-year-old woman who developed complex regional pain syndrome type-I (CRPS-I) with spread phenomenon. She had received lumbar SCS under a diagnosis of CRPS-I in her left leg for 8 years. She had refractory pain in her right arm for the recent two years. There was no new lesion explaining her refractory pain on physical or radiological examination. Thus, the pain in her right upper arm was considered as spread phenomenon of CRPS-I. Test stimulation with cervical epidural spinal electrode showed good results and the pulse generator was implanted. It is suggested that the symptom of CRPS-I involving spread phenomenon was possibly due to a cortical reorganization. But a certain effect of SCS may be contributing to the favorable results of test stimulation for the treatment of CRPS-I with spread phenomenon in this case.

TENS (transcutaneous electrical nerve stimulation) for labour pain.

PubMed

Francis, Richard

2012-05-01

Because TENS is applied inconsistently and not always in line with optimal TENS application theory, this may explain why TENS for labour pain appears to be effective in some individuals and not in others. This article reviews TENS theory, advises upon optimal TENS application for labour pain and discusses some of the limitations of TENS research on labour pain. TENS application for labour pain may include TENS applied to either side of the lower spine, set to 200 mus pulse duration and 100 pulses per second. As pain increases, TENS intensity should be increased and as pain decreases, TENS intensity should be reduced to maintain a strong but pain free intensity of stimulation. This application may particularly reduce back pain during labour.

Children acceptance of laser dental treatment

NASA Astrophysics Data System (ADS)

Lazea, Andreea; Todea, Carmen

2016-03-01

Objectives: To evaluate the dental anxiety level and the degree of acceptance of laser assisted pedodontic treatments from the children part. Also, we want to underline the advantages of laser use in pediatric dentistry, to make this technology widely used in treating dental problems of our children patients. Methods: Thirty pediatric dental patients presented in the Department of Pedodontics, University of Medicine and Pharmacy "Victor Babeş", Timişoara were evaluated using the Wong-Baker pain rating scale, wich was administered postoperatory to all patients, to assess their level of laser therapy acceptance. Results: Wong-Baker faces pain rating scale (WBFPS) has good validity and high specificity; generally it's easy for children to use, easy to compare and has good feasibility. Laser treatment has been accepted and tolerated by pediatric patients for its ability to reduce or eliminate pain. Around 70% of the total sample showed an excellent acceptance of laser dental treatment. Conclusions: Laser technology is useful and effective in many clinical situations encountered in pediatric dentistry and a good level of pacient acceptance is reported during all laser procedures on hard and soft tissues.

Palmar skin conductance variability and the relation to stimulation, pain and the motor activity assessment scale in intensive care unit patients

PubMed Central

2013-01-01

Introduction Many intensive care unit (ICU) patients describe pain and other adverse feelings that may impact long-term psychological morbidity. Sympathetically mediated palmar skin conductance variability is related to emotionally induced perspiration and correlates with pain levels in the perioperative setting but has not been studied in ICU patients. Methods Twenty non-intubated and 20 intubated general ICU patients were included in this observational study. Patients were monitored with the MED-STORM Pain Monitoring System®. The number of skin conductance fluctuations per second (NSCF) was measured in parallel with bedside observation during one hour of intensive care, including rest, procedures and patient-staff interactions. Arousal-agitation level was monitored with the motor activity assessment scale (MAAS). Pain was monitored with the numeric rating scale (0 to 10) in patients able to communicate or by observation in patients unable to communicate. Results In non-intubated patients, NSCF increased with increasing stimulation/pain but also with higher MAAS (P = 0.002). An interaction effect was found, with increased NSCF response to stimulation/pain with increasing MAAS (P < 0.001). In intubated patients, NSCF increased significantly with increasing stimulation/pain (P < 0.001). In contrast to non-intubated patients, no difference in NSCF between MAAS levels was found for any given degree of stimulation in intubated patients. Conclusions In critically ill patients, NSCF may be more useful evaluating emotional distress rather than pain alone. It needs to be assessed whether NSCF monitoring is clinically useful and whether controlling emotional distress with the aid of such monitoring may impact on patient care and outcomes. PMID:23510014

Clinically Effective Treatment of Fibromyalgia Pain With High-Definition Transcranial Direct Current Stimulation: Phase II Open-Label Dose Optimization.

PubMed

Castillo-Saavedra, Laura; Gebodh, Nigel; Bikson, Marom; Diaz-Cruz, Camilo; Brandao, Rivail; Coutinho, Livia; Truong, Dennis; Datta, Abhishek; Shani-Hershkovich, Revital; Weiss, Michal; Laufer, Ilan; Reches, Amit; Peremen, Ziv; Geva, Amir; Parra, Lucas C; Fregni, Felipe

2016-01-01

Despite promising preliminary results in treating fibromyalgia (FM) pain, no neuromodulation technique has been adopted in clinical practice because of limited efficacy, low response rate, or poor tolerability. This phase II open-label trial aims to define a methodology for a clinically effective treatment of pain in FM by establishing treatment protocols and screening procedures to maximize efficacy and response rate. High-definition transcranial direct current stimulation (HD-tDCS) provides targeted subthreshold brain stimulation, combining tolerability with specificity. We aimed to establish the number of HD-tDCS sessions required to achieve a 50% FM pain reduction, and to characterize the biometrics of the response, including brain network activation pain scores of contact heat-evoked potentials. We report a clinically significant benefit of a 50% pain reduction in half (n = 7) of the patients (N = 14), with responders and nonresponders alike benefiting from a cumulative effect of treatment, reflected in significant pain reduction (P = .035) as well as improved quality of life (P = .001) over time. We also report an aggregate 6-week response rate of 50% of patients and estimate 15 as the median number of HD-tDCS sessions to reach clinically meaningful outcomes. The methodology for a pivotal FM neuromodulation clinical trial with individualized treatment is thus supported. Registered in Clinicaltrials.gov under registry number NCT01842009. In this article, an optimized protocol for the treatment of fibromyalgia pain with targeted subthreshold brain stimulation using high-definition transcranial direct current stimulation is outlined. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

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.

PubMed

Chow, Roberta T; David, Monique A; Armati, Patricia J

2007-03-01

We 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 (p<0.005) in MMP in mitochondria in and between static axonal varicosities. In cell bodies of the neuron, the decrease in MMP was also statistically significant (p<0.05), 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 microm/s (range 0.5-2 microm/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.

Cerebral responses to innocuous somatic pressure stimulation following aerobic exercise rehabilitation in chronic pain patients: a functional magnetic resonance imaging study

PubMed Central

Micalos, Peter S; Korgaonkar, Mayuresh S; Drinkwater, Eric J; Cannon, Jack; Marino, Frank E

2014-01-01

Objective The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain. Materials and methods Eleven chronic pain patients and eight healthy pain-free controls completed 12 weeks of supervised aerobic exercise intervention. Perceptual rating of standardized somatic pressure stimulation (2 kg) on the right anterior mid-thigh and brain responses during functional magnetic resonance imaging (fMRI) were assessed at pre- and postexercise rehabilitation. Results There was a significant difference in the perceptual rating of innocuous somatic pressure stimulation between the chronic pain and control groups (P=0.02) but no difference following exercise rehabilitation. Whole brain voxel-wise analysis with correction for multiple comparisons revealed trends for differences in fMRI responses between the chronic pain and control groups in the superior temporal gyrus (chronic pain > control, corrected P=0.30), thalamus, and caudate (control > chronic, corrected P=0.23). Repeated measures of the regions of interest (5 mm radius) for blood oxygen level-dependent signal response revealed trend differences for superior temporal gyrus (P=0.06), thalamus (P=0.04), and caudate (P=0.21). Group-by-time interactions revealed trend differences in the caudate (P=0.10) and superior temporal gyrus (P=0.29). Conclusion Augmented perceptual and brain responses to innocuous somatic pressure stimulation were shown in the chronic pain group compared to the control group; however, 12-weeks of exercise rehabilitation did not significantly attenuate these responses. PMID:25210471

Effects of chondroitin sulfate on brain response to painful stimulation in knee osteoarthritis patients. A randomized, double-blind, placebo-controlled functional magnetic resonance imaging study.

PubMed

Monfort, Jordi; Pujol, Jesús; Contreras-Rodríguez, Oren; Llorente-Onaindia, Jone; López-Solà, Marina; Blanco-Hinojo, Laura; Vergés, Josep; Herrero, Marta; Sánchez, Laura; Ortiz, Hector; Montañés, Francisco; Deus, Joan; Benito, Pere

2017-06-21

Knee osteoarthritis is causing pain and functional disability. One of the inherent problems with efficacy assessment of pain medication was the lack of objective pain measurements, but functional magnetic resonance imaging (fMRI) has emerged as a useful means to objectify brain response to painful stimulation. We have investigated the effect of chondroitin sulfate (CS) on brain response to knee painful stimulation in patients with knee osteoarthritis using fMRI. Twenty-two patients received CS (800mg/day) and 27 patients placebo, and were assessed at baseline and after 4 months of treatment. Two fMRI tests were conducted in each session by applying painful pressure on the knee interline and on the patella surface. The outcome measurement was attenuation of the response evoked by knee painful stimulation in the brain. fMRI of patella pain showed significantly greater activation reduction under CS compared with placebo in the region of the mesencephalic periaquecductal gray. The CS group, additionally showed pre/post-treatment activation reduction in the cortical representation of the leg. No effects of CS were detected using the interline pressure test. fMRI was sensitive to objectify CS effects on brain response to painful pressure on patellofemoral cartilage, which is consistent with the known CS action on chondrocyte regeneration. The current work yields further support to the utility of fMRI to objectify treatment effects on osteoarthritis pain. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Correlation fluorescence method of amine detection

NASA Astrophysics Data System (ADS)

Myslitsky, Valentin F.; Tkachuk, Svetlana S.; Rudeichuk, Volodimir M.; Strinadko, Miroslav T.; Slyotov, Mikhail M.; Strinadko, Marina M.

1997-12-01

The amines fluorescence spectra stimulated by UV laser radiation are investigated in this paper. The fluorescence is stimulated by the coherent laser beam with the wavelength 0.337 micrometers . At the sufficient energy of laser stimulation the narrow peaks of the fluorescence spectra are detected besides the wide maximum. The relationship between the fluorescence intensity and the concentration of amines solutions are investigated. The fluorescence intensity temporal dependence on wavelength 0.363 micrometers of the norepinephrine solution preliminarily radiated by UV laser with wavelength 0.337 micrometers was found. The computer stimulated and experimental investigations of adrenaline and norepinephrine mixtures fluorescence spectra were done. The correlation fluorescent method of amines detection is proposed.

Effect of Transcutaneous Electrical Nerve Stimulation on Sensation Thresholds in Patients with Painful Diabetic Neuropathy: An Observational Study

ERIC Educational Resources Information Center

Moharic, Metka

2010-01-01

Transcutaneous electrical nerve stimulation (TENS) is one of the therapies for painful neuropathy. Its analgesic mechanisms probably involve the gate control theory, the physiological block and the endogenous pain inhibitory system. The aim of the study was to determine whether TENS improves small fibre function diminished because of painful…

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

PubMed

Esper, Maria Angela Lacerda Rangel; Nicolau, Renata Amadei; Arisawa, Emília Angela Lo Schiavo

2011-09-01

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.

Neuropathic Pain Causes Pyramidal Neuronal Hyperactivity in the Anterior Cingulate Cortex.

PubMed

Zhao, Ruohe; Zhou, Hang; Huang, Lianyan; Xie, Zhongcong; Wang, Jing; Gan, Wen-Biao; Yang, Guang

2018-01-01

The anterior cingulate cortex (ACC) is thought to be important for acute pain perception as well as the development of chronic pain after peripheral nerve injury. Nevertheless, how ACC neurons respond to sensory stimulation under chronic pain states is not well understood. Here, we used an in vivo two-photon imaging technique to monitor the activity of individual neurons in the ACC of awake, head restrained mice. Calcium imaging in the dorsal ACC revealed robust somatic activity in layer 5 (L5) pyramidal neurons in response to peripheral noxious stimuli, and the degree of evoked activity was correlated with the intensity of noxious stimulation. Furthermore, the activation of ACC neurons occurred bilaterally upon noxious stimulation to either contralateral or ipsilateral hind paws. Notably, with nerve injury-induced neuropathic pain in one limb, L5 pyramidal neurons in both sides of the ACC showed enhanced activity in the absence or presence of pain stimuli. These results reveal hyperactivity of L5 pyramidal neurons in the bilateral ACC during the development of neuropathic pain.

Laser phototherapy as topical prophylaxis against head and neck cancer radiotherapy-induced oral mucositis: comparison between low and high/low power lasers.

PubMed

Simões, Alyne; Eduardo, Fernanda P; Luiz, Ana Claudia; Campos, Luana; Sá, Pedro Henrique R N; Cristófaro, Márcio; Marques, Márcia M; Eduardo, Carlos P

2009-04-01

Oral mucositis is a dose-limiting and painful side effect of radiotherapy (RT) and/or chemotherapy in cancer patients. The purpose of the present study was to analyze the effect of different protocols of laser phototherapy (LPT) on the grade of mucositis and degree of pain in patients under RT. Thirty-nine patients were divided into three groups: G1, where the irradiations were done three times a week using low power laser; G2, where combined high and low power lasers were used three time a week; and G3, where patients received low power laser irradiation once a week. The low power LPT was done using an InGaAlP laser (660 nm/40 mW/6 J cm(-2)/0.24 J per point). In the combined protocol, the high power LPT was done using a GaAlAs laser (808 nm, 1 W/cm(2)). Oral mucositis was assessed at each LPT session in accordance to the oral-mucositis scale of the National Institute of the Cancer-Common Toxicity criteria (NIC-CTC). The patient self-assessed pain was measured by means of the visual analogue scale. All protocols of LPT led to the maintenance of oral mucositis scores in the same levels until the last RT session. Moreover, LPT three times a week also maintained the pain levels. However, the patients submitted to the once a week LPT had significant pain increase; and the association of low/high LPT led to increased healing time. These findings are desired when dealing with oncologic patients under RT avoiding unplanned radiation treatment breaks and additional hospital costs.

Photobiomodulation therapy by NIR laser in persistent pain: an analytical study in the rat.

PubMed

Micheli, Laura; Di Cesare Mannelli, Lorenzo; Lucarini, Elena; Cialdai, Francesca; Vignali, Leonardo; Ghelardini, Carla; Monici, Monica

2017-11-01

Over the past three decades, physicians have used laser sources for the management of different pain conditions obtaining controversial results that call for further investigations. In order to evaluate the pain relieving possibilities of photobiomodulation therapy (PBMT), we tested two near infrared (NIR) laser systems, with different power, against various kinds of persistent hyperalgesia animal models. In rats, articular pain was reproduced by the intra-articular injection of sodium monoiodoacetate (MIA) and complete Freund's adjuvant (CFA), while compressive neuropathy was modelled by the chronic constriction injury of the sciatic nerve (CCI). In MIA and CFA models, (NIR) laser (MLS-Mphi, ASA S.r.l., Vicenza, Italy) application was started 14 days after injury and was performed once a day for a total of 13 applications. In MIA-treated animals, the anti-hyperalgesic effect of laser began 5 min after treatment and vanished after 60 min. The subsequent applications evoked similar effects. In CFA-treated rats, laser efficacy started 5 min after treatment and disappeared after 180 min. In rats that underwent CCI, two treatment protocols with similar fluence but different power output were tested using a new experimental device called Multiwave Locked System laser (MLS-HPP). Treatments began 7 days after injury and were performed during 3 weeks for a total of 10 applications. Both protocols reduced mechanical hyperalgesia and hindlimb weight bearing alterations until 60 min after treatment with a higher efficacy recorded for the animals treated using the higher power output. In conclusion, this study supports laser therapy as a potential treatment for immediate relief of chronic articular or neuropathic pain.

Optimal management of orthodontic pain.

PubMed

Topolski, Francielle; Moro, Alexandre; Correr, Gisele Maria; Schimim, Sasha Cristina

2018-01-01

Pain is an undesirable side effect of orthodontic tooth movement, which causes many patients to give up orthodontic treatment or avoid it altogether. The aim of this study was to investigate, through an analysis of the scientific literature, the best method for managing orthodontic pain. The methodological aspects involved careful definition of keywords and diligent search in databases of scientific articles published in the English language, without any restriction of publication date. We recovered 1281 articles. After the filtering and classification of these articles, 56 randomized clinical trials were selected. Of these, 19 evaluated the effects of different types of drugs for the control of orthodontic pain, 16 evaluated the effects of low-level laser therapy on orthodontic pain, and 21 evaluated other methods of pain control. Drugs reported as effective in orthodontic pain control included ibuprofen, paracetamol, naproxen sodium, aspirin, etoricoxib, meloxicam, piroxicam, and tenoxicam. Most studies report favorable outcomes in terms of alleviation of orthodontic pain with the use of low-level laser therapy. Nevertheless, we noticed that there is no consensus, both for the drug and for laser therapy, on the doses and clinical protocols most appropriate for orthodontic pain management. Alternative methods for orthodontic pain control can also broaden the clinician's range of options in the search for better patient care.

Optimal management of orthodontic pain

PubMed Central

Topolski, Francielle; Moro, Alexandre; Correr, Gisele Maria; Schimim, Sasha Cristina

2018-01-01

Pain is an undesirable side effect of orthodontic tooth movement, which causes many patients to give up orthodontic treatment or avoid it altogether. The aim of this study was to investigate, through an analysis of the scientific literature, the best method for managing orthodontic pain. The methodological aspects involved careful definition of keywords and diligent search in databases of scientific articles published in the English language, without any restriction of publication date. We recovered 1281 articles. After the filtering and classification of these articles, 56 randomized clinical trials were selected. Of these, 19 evaluated the effects of different types of drugs for the control of orthodontic pain, 16 evaluated the effects of low-level laser therapy on orthodontic pain, and 21 evaluated other methods of pain control. Drugs reported as effective in orthodontic pain control included ibuprofen, paracetamol, naproxen sodium, aspirin, etoricoxib, meloxicam, piroxicam, and tenoxicam. Most studies report favorable outcomes in terms of alleviation of orthodontic pain with the use of low-level laser therapy. Nevertheless, we noticed that there is no consensus, both for the drug and for laser therapy, on the doses and clinical protocols most appropriate for orthodontic pain management. Alternative methods for orthodontic pain control can also broaden the clinician’s range of options in the search for better patient care. PMID:29588616

[Assessment of the pain patients with the multiple sclerosis after applying the physiotherapy treatment].

PubMed

Kubsik, Anna; Klimkiewicz, Robert; Klimkiewicz, Paulina; Janczewska, Katarzyna; Jankowska, Agnieszka; Łukasiak, Adam; Woldańska-Okońska, Marta

2016-04-01

Multiple sclerosis is one of the most common demyelinating disease of the CNS connected with the autoimmune action. The effect of the disease is progressive disability, and one of the symptoms is pain. In relieving pain in the course of MS physical procedures and exercises of physiotherapy are used. The aim of the study was assessment of the pain in patients with the multiple sclerosis after applying laser radiation, magnetostimulation and kinesiotherapy. The studied material was consisted of 120 patients with multiple sclerosis of both sexes (82 women and 38 men) aged 21-81 years. Patients were randomly divided into 4 treatment groups and the assesment was performed three times. In the first group laser therapy, in the group II laser and magnetostimulation, in the third group kinesiotherapy, in the fourth group magnetostimulation was used. The same program of physiotherapy in all groups was used. All patients were performed the following tests to assess of the pain: The Laitinen Modified Questionnaire Indicators of Pain of and the Visual- Analogue Scale (VAS). In all treatment groups was observed tends to decrease a result of a point in The Laitinen Modified Questionnaire Indicators of Pain and the Visual-Analogue Scale (VAS). Correlation between groups demonstrated statistically significant result on the level p<0.05 in the group where the laser treatment was applied towards group II assessed with parameter of the Questionnaire of Pain according to Laitinen, as well as towards group II and III assessed with parameter - of the Visual Analogue Scale (VAS). The good result, i.e. the reduction of the spot value, after the III examination towards the preliminary examination were got in the group II. Laser radiation is an effective method which has an analgesisc action. The combination of laser radiation and magnetostimulation reduces pain in patients with multiple sclerosis, and also allows to maintain a therapeutic effect even after the cessation of the application of these procedures, which indicates the possibility to elicitation the biological phenomenon of hysteresis in these methods. © 2016 MEDPRESS.

[An 18 month evaluation of MM-MTA pulpotomy on primary decayed molars].

PubMed

Abou Chedid, J C; Mchayleh, N; Khalil, I; Melki, B; Hardan, L S

2015-12-01

Pulpotomy is the most performed and controversial therapeutic in pediatric dentistry. Formocresol is known to have a toxic effect on living tissues, a mutagenic and carcinogenic potential with a systemic uptake of formocresol via pulpotomized teeth, other alternative products have been investigated. 40 molars were pulpotomized using Micro Mega Mineral Trioxide Aggregate (MM-MTA), which eliminates the need for the use of formocresol. The effects of this material were evaluated both clinically and radiographically. Post-operative control examinations were performed at 1, 6, 12, and 18 months trying to detect spontaneous or stimulated pain, pathological tooth mobility, abscesses or fistulas, internal or external pathological tooth resorption, periapical bone destruction, or canal obliteration. Pain was absent at 18 months post operatively. Thirty six molar treated with the MM-MTA didn't show any mobility or pain, one molar presented a pathological resorption and one molar presented an abscess without a fistula at 12 month. The observations were compared to others related to formocresol, ferric sulfate, MTA, and laser pulpotomies, using the Chi-square test x2. The abundance of positive result strongly demonstrate that the MM-MTA pulpotomy on carious temporary molars is a promising technique.

High-Definition and Non-Invasive Brain Modulation of Pain and Motor Dysfunction in Chronic TMD

PubMed Central

Donnell, Adam; Nascimento, Thiago; Lawrence, Mara; Gupta, Vikas; Zieba, Tina; Truong, Dennis Q.; Bikson, Marom; Datta, Abhi; Bellile, Emily; DaSilva, Alexandre F.

2015-01-01

Background Temporomandibular disorders (TMD) have a relatively high prevalence and in many patients pain and masticatory dysfunction persist despite a range of treatments. Non-invasive brain neuromodulatory methods, namely transcranial direct current stimulation (tDCS), can provide relatively long-lasting pain relief in chronic pain patients. Objective To define the neuromodulatory effect of five daily 2×2 motor cortex high-definition tDCS (HD-tDCS) sessions on clinical pain and motor measures in chronic TMD patients. It is predicted that M1 HD-tDCS will selectively modulate clinical measures, by showing greater analgesic after-effects compared to placebo, and active treatment will increase pain free jaw movement more than placebo. Methods Twenty-four females with chronic myofascial TMD pain underwent five daily, 20-minute sessions of active or sham 2 milliamps (mA) HD-tDCS. Measurable outcomes included pain-free mouth opening, visual analog scale (VAS), sectional sensory-discriminative pain measures tracked by a mobile application, short form of the McGill Pain Questionnaire, and the Positive and Negative Affect Schedule. Follow-up occurred at one-week and four-weeks post treatment. Results There were significant improvements for clinical pain and motor measurements in the active HD-tDCS group compared to the placebo group for: responders with pain relief above 50% in the VAS at four-week follow-up (p=0.04); pain-free mouth opening at one-week follow-up (p<0.01); and sectional pain area, intensity and their sum measures contralateral to putative M1 stimulation during the treatment week (p<0.01). No changes in emotional values were shown between groups. Conclusion Putative M1 stimulation by HD-tDCS selectively improved meaningful clinical sensory-discriminative pain and motor measures during stimulation, and up to four weeks post-treatment in chronic myofascial TMD pain patients. PMID:26226938

Efficacy of deep rTMS for neuropathic pain in the lower limb: a randomized, double-blind crossover trial of an H-coil and figure-8 coil.

PubMed

Shimizu, Takeshi; Hosomi, Koichi; Maruo, Tomoyuki; Goto, Yuko; Yokoe, Masaru; Kageyama, Yu; Shimokawa, Toshio; Yoshimine, Toshiki; Saitoh, Youichi

2017-11-01

OBJECTIVE Electrical motor cortex stimulation can relieve neuropathic pain (NP), but its use requires patients to undergo an invasive procedure. Repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) using a figure-8 coil can relieve NP noninvasively, but its ability to relieve lower limb pain is still limited. Deep rTMS using an H-coil can effectively stimulate deep brain regions and has been widely used for the treatment of various neurological diseases; however, there have been no clinical studies comparing the effectiveness of figure-8 coils and H-coils. This study assessed the clinical effectiveness of 5 once-daily stimulations with H-coils and figure-8 coils in patients with NP. METHODS This randomized, double-blind, 3-way crossover trial examined 18 patients with NP who sequentially received 3 types of stimulations in the M1 for 5 consecutive days; each 5-day stimulation period was followed by a 17-day follow-up period before crossing over to the next type of stimulation. During each rTMS session, patients received a 5-Hz rTMS to the M1 region corresponding to the painful lower limb. The visual analog scale (VAS) and the Japanese version of the short-form McGill Pain Questionnaire 2 (SF-MPQ2-J) were used to measure pain intensity. The primary outcome was VAS score reduction immediately after and 1 hour after intervention. RESULTS Both the VAS and SF-MPQ2-J showed significant pain improvement immediately after deep rTMS with an H-coil as compared with the sham group (p < 0.001 and p = 0.049, respectively). However, neither outcome measure showed significant pain improvement when using a figure-8 coil. The VAS also showed significant pain improvement 1 hour after deep rTMS with an H-coil (p = 0.004) but not 1 hour after rTMS using a figure-8 coil. None of the patients exhibited any serious adverse events. CONCLUSIONS The current findings suggest that the use of deep rTMS with an H-coil in the lower limb region of the M1 in patients with NP was tolerable and could provide significant short-term pain relief. Clinical trial registration no.: UMIN000010536 ( http://www.umin.ac.jp/ctr/ ).

Laser Stimulation of Single Auditory Nerve Fibers

PubMed Central

Littlefield, Philip D.; Vujanovic, Irena; Mundi, Jagmeet; Matic, Agnella Izzo; Richter, Claus-Peter

2011-01-01

Objectives/Hypothesis One limitation with cochlear implants is the difficulty stimulating spatially discrete spiral ganglion cell groups because of electrode interactions. Multipolar electrodes have improved on this some, but also at the cost of much higher device power consumption. Recently, it has been shown that spatially selective stimulation of the auditory nerve is possible with a mid-infrared laser aimed at the spiral ganglion via the round window. However, these neurons must be driven at adequate rates for optical radiation to be useful in cochlear implants. We herein use single-fiber recordings to characterize the responses of auditory neurons to optical radiation. Study Design In vivo study using normal-hearing adult gerbils. Methods Two diode lasers were used for stimulation of the auditory nerve. They operated between 1.844 μm and 1.873 μm, with pulse durations of 35 μs to 1,000 μs, and at repetition rates up to 1,000 pulses per second (pps). The laser outputs were coupled to a 200-μm-diameter optical fiber placed against the round window membrane and oriented toward the spiral ganglion. The auditory nerve was exposed through a craniotomy, and recordings were taken from single fibers during acoustic and laser stimulation. Results Action potentials occurred 2.5 ms to 4.0 ms after the laser pulse. The latency jitter was up to 3 ms. Maximum rates of discharge averaged 97 ± 52.5 action potentials per second. The neurons did not strictly respond to the laser at stimulation rates over 100 pps. Conclusions Auditory neurons can be stimulated by a laser beam passing through the round window membrane and driven at rates sufficient for useful auditory information. Optical stimulation and electrical stimulation have different characteristics; which could be selectively exploited in future cochlear implants. Level of Evidence Not applicable. PMID:20830761

Stimulated emission in quantum well laser diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blood, P.

1989-07-03

We observe that stimulated emission from inhomogeneously pumped quantum well laser diodes is shifted down in energy compared with the subband transition energy. Measured spontaneous emission spectra show that this stimulated emission is due to band-to-band transitions shifted by renormalization at high injected carrier densities, and we suggest that this same mechanism explains reported observations of stimulated emission from inhomogeneously photopumped structures which previously have been interpreted as evidence for longitudinal optic (LO) phonon participation. We show that LO phonon participation cannot account for the photon energy of stimulated emission from conventional homogeneously pumped quantum well laser diodes.

Utilization of multiple spinal cord stimulation (SCS) waveforms in chronic pain patients.

PubMed

Berg, Anthony P; Mekel-Bobrov, Nitzan; Goldberg, Edward; Huynh, Dat; Jain, Roshini

2017-08-01

Advances in spinal cord stimulation (SCS) have improved patient outcomes, leading to its increased utilization for chronic pain. Chronic pain is dynamic showing exacerbations, variable severity, and evolving pain patterns. Given this complexity, SCS systems that provide a broad range of stimulation waveforms may be valuable. The aim of this research was to characterize the usage pattern of stimulation waveforms and field shapes in chronic pain patients implanted with the Spectra System. A review of daily device usage in a cohort of 250 patients implanted for a minimum duration of one month was conducted. With follow-ups ranging between 1 month and 1 year post-implant, 72.8% of patients used Standard Rate, 34.8% Anode Intensification, 23.2% Higher Rate, and 8.4% Burst stimulation waveforms. Collectively, 60% used 1 or more advanced waveforms, either exclusively or along with Standard Rate. A trend showed patients continuing to use up to 3 programs one year post-implant. When given a choice, SCS patients often utilize a variety of waveforms, suggesting that patients may benefit from a single system that provides multiple waveforms and field shapes to customize therapy and improve efficacy.

Experimental tooth pain elevates substance P and matrix metalloproteinase-8 levels in human gingival crevice fluid.

PubMed

Avellán, Nina-Li; Sorsa, Timo; Tervahartiala, Taina; Forster, Clemens; Kemppainen, Pentti

2008-02-01

Tooth pain can induce a neurogenic inflammatory reaction in gingiva in association with local elevations of matrix metalloproteinase (MMP)-8, which is considered the major tissue destructive protease in gingival crevice fluid (GCF). The pro-inflammatory neuropeptides released by sensory nerves coordinate the activities of the immuno-effector cells and may influence the secretion of MMP-8. With this background, we studied whether experimental tooth pain can trigger changes in GCF levels of the neuropeptide substance P (SP) and MMP-8. The GCF SP levels of stimulated and non-stimulated teeth were analyzed for SP using a competitive enzyme immunoassay (EIA). The GCF MMP-8 levels were determined by quantitative immunofluorometric assay (IFMA). Painful stimulation of the upper central incisor caused significant elevations in GCF SP and MMP-8 levels of the stimulated tooth. At the same time, the GCF SP and MMP-8 levels of non-stimulated control teeth were unchanged. These data indicate that experimental tooth pain can induce local elevations of SP and MMP-8 levels in GCF simultaneously. This supports the possibility of a local neurogenic spread of inflammatory reactions from intrapulpal to surrounding periodontal tissues.

Motor Cortex Stimulation for Pain Relief: Do Corollary Discharges Play a Role?

PubMed

Brasil-Neto, Joaquim P

2016-01-01

Both invasive and non-invasive motor cortex stimulation techniques have been successfully employed in the treatment of chronic pain, but the precise mechanism of action of such treatments is not fully understood. It has been hypothesized that a mismatch of normal interaction between motor intention and sensory feedback may result in central pain. Sensory feedback may come from peripheral nerves, vision and also from corollary discharges originating from the motor cortex itself. Therefore, a possible mechanism of action of motor cortex stimulation might be corollary discharge reinforcement, which could counterbalance sensory feedback deficiency. In other instances, primary deficiency in the production of corollary discharges by the motor cortex might be the culprit and stimulation of cortical motor areas might then be beneficial by enhancing production of such discharges. Here we review evidence for a possible role of motor cortex corollary discharges upon both the pathophysiology and the response to motor cortex stimulation of different types of chronic pain. We further suggest that the right dorsolateral prefrontal cortex (DLPC), thought to constantly monitor incongruity between corollary discharges, vision and proprioception, might be an interesting target for non-invasive neuromodulation in cases of chronic neuropathic pain.

Diffuse correlation spectroscopy (DCS) study of blood flow changes during low level laser therapy (LLLT): a preliminary report

NASA Astrophysics Data System (ADS)

Soni, Sagar; Wang, Xinlong; Liu, Hanli; Tian, Fenghua

2017-02-01

Photobiomodulation with low-power, high-fluence light in the near-infrared range (600-1100nm), also known as low level laser therapy (LLLT), has been used for promoting healing of wounds, reducing pain, and so on. Understanding its physiological effect is essential for treatment optimization and evaluation. In this study, we used diffuse correlation spectroscopy (DCS) to investigate the changes of regional blood flow in skeletal muscle induced by a single session of LLLT. DCS is an emerging optical modality to probe microvascular blood flow in human tissues in vivo. We have developed a software-based autocorrelator system with the benefits such as flexibility in raw photon count data processing, portability and low cost. LLLT was administered at the human forearm with a 1064-nm, continuous-wave laser. The emitting power was 3.4 W in an area of 13.6 cm2, corresponding to 0.25W/cm2 irradiance. The emitting duration was 10 minutes. Eight healthy adults of any ethnic background, in an age range of 18-40 years old were included. The results indicate that LLLT causes reliable changes in regional blood flow. However, it remains unclear whether these changes are physiological or attributed to the heating effect of the stimulation laser.

21 CFR 882.5840 - Implanted intracerebral/subcortical stimulator for pain relief.

Code of Federal Regulations, 2013 CFR

2013-04-01

... to subsurface areas of a patient's brain to treat severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed within a patient's brain and an external...

21 CFR 882.5840 - Implanted intracerebral/subcortical stimulator for pain relief.

Code of Federal Regulations, 2012 CFR

2012-04-01

... to subsurface areas of a patient's brain to treat severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed within a patient's brain and an external...

21 CFR 882.5840 - Implanted intracerebral/subcortical stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... to subsurface areas of a patient's brain to treat severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed within a patient's brain and an external...

21 CFR 882.5840 - Implanted intracerebral/subcortical stimulator for pain relief.

Code of Federal Regulations, 2014 CFR

2014-04-01

... to subsurface areas of a patient's brain to treat severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed within a patient's brain and an external...

21 CFR 882.5840 - Implanted intracerebral/subcortical stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to subsurface areas of a patient's brain to treat severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed within a patient's brain and an external...

Interest of repetitive transcranial magnetic stimulation of the motor cortex in the management of refractory cancer pain in palliative care: Two case reports.

PubMed

Nizard, Julien; Levesque, Amélie; Denis, Nathalie; de Chauvigny, Edwige; Lepeintre, Aurélie; Raoul, Sylvie; Labat, Jean-Jacques; Bulteau, Samuel; Maillard, Benoît; Buffenoir, Kevin; Potel, Gilles; Lefaucheur, Jean-Pascal; Nguyen, Jean Paul

2015-06-01

Non-drug treatments should be systematically associated to the medical analgesic treatment during the terminal phase of cancer. Patient 1, a 23-year-old woman, presented an adenocarcinoma of the rectum, with liver and lung metastases. Pain was initially treated by oral morphine and a combination of pregabalin and amitriptyline. Ketamine and intrathecal administration of morphine were both ineffective. Patient 2, a 69-year-old woman, presented a cutaneous T-cell lymphoma. She was admitted to the palliative care unit with mixed pain related to cutaneous lymphomatous infiltration. World Health Organization (WHO) step 3 analgesics had not been tolerated. Both patients received five consecutive 20-min sessions of repetitive transcranial magnetic stimulation to the right motor cortex. Patient 1 experienced a marked improvement of her pain over the days following the first repetitive transcranial magnetic stimulation session. Medical treatment was able to be rapidly decreased by about 50%, which restored an almost normal level of consciousness and lucidity. Patient 2's pain was also markedly decreased over the days following these five consecutive sessions, and repetitive transcranial magnetic stimulation also appeared to have had a beneficial effect on the patient's anxiety and mood. In the context of palliative care of cancer patients experiencing refractory pain that is difficult to control by the usual treatments, motor cortex repetitive transcranial magnetic stimulation, due to its noninvasive nature, can be used as an adjuvant therapy to improve various components of pain, including the emotional components. By reducing the doses of analgesics, repetitive transcranial magnetic stimulation decreases the severity of their adverse effects and improves the patient's quality of life. © The Author(s) 2015.

High Intensity Laser Therapy (HILT) versus TENS and NSAIDs in low back pain: clinical study

NASA Astrophysics Data System (ADS)

Zati, Allesandro; Fortuna, Damiano; Valent, A.; Filippi, M. V.; Bilotta, Teresa W.

2004-09-01

Low back pain, caused by lumbar disc herniation, is prevalently treated with a conservative approach. In this study we valued the efficacy of High Intensity Laser Therapy (HILT), compared with accepted therapies such as TENS and NSAIDs. Laser therapy obtained similar results in the short term, but better clinical effect over time than TENS and NSAIDs. In conclusion high intensity laser therapy appears to be a interesting new treatment, worthy of further research.

Psychobiological response to pain in female adolescents with nonsuicidal self-injury

PubMed Central

Koenig, Julian; Rinnewitz, Lena; Warth, Marco; Hillecke, Thomas K.; Brunner, Romuald; Resch, Franz; Kaess, Michael

2017-01-01

Background Nonsuicidal self-injury (NSSI) is associated with reduced pain sensitivity and alterations in top–down processing of nociceptive information. The experience of acute pain is characterized by reactivity of the autonomic nervous system (ANS) and hypothalamic–pituitary–adrenal (HPA) axis, which to our knowledge has not been systematically investigated in the context of NSSI. Methods Adolescents fulfilling DSM-5 diagnostic criteria for NSSI and matched healthy controls received cold pain stimulation. We obtained self-reports on psychological distress and measured blood pressure, heart rate variability (HRV) and saliva cortisol. Regression analyses were used to investigate group differences on observed difference scores, adjusting for confounding variables. Results We included 30 adolescents engaging in NSSI and 30 controls in our study. Adolescents in the NSSI group showed a greater pain threshold. Groups significantly differed in their psychological response to pain. In patients with NSSI, mood and body awareness increased after painful stimulation; in controls it decreased. Tension increased in controls only. The HPA axis response to painful stimulation was increased in the NSSI compared with the control group. Analysis of ultra-short-term recordings of HRV revealed significant group differences during the anticipation of pain and recovery. Limitations Future studies should incorporate multiple measures of saliva cortisol and replicate the present findings in a naturalistic setting. Conclusion Compared with controls, individuals engaging in NSSI show psychological benefits in response to pain. Biological findings highlight decreased physiologic arousal before and prolonged arousal (ANS and HPA axis response) after painful stimulation in adolescents engaging in NSSI. Greater pain-inflicted autonomic arousal and cortisol secretion may counteract dissociative states, reduce negative affect and increase body awareness in adolescents engaging in NSSI, lending support for a neurobiological pathomechanism underlying the intraindividual and antisuicide functions of NSSI. PMID:28234208

Electrical high-frequency stimulation of the human thoracolumbar fascia evokes long-term potentiation-like pain amplification.

PubMed

Schilder, Andreas; Magerl, Walter; Hoheisel, Ulrich; Klein, Thomas; Treede, Rolf-Detlef

2016-10-01

Nociceptive long-term potentiation, a use dependent increase in synaptic efficacy in the dorsal horn of the spinal cord is thought to contribute to the development of persistent pain states. So far, no study has analyzed the effects of high-frequency stimulation (HFS) of afferents from deep tissues (muscle and fascia) on pain perception in the back in humans. In 16 healthy volunteers, the multifidus muscle and the overlying thoracolumbar fascia were stimulated with electrical high-frequency pulses (5 × 100 pulses at 100 Hz) through bipolar concentric needle electrodes placed at lumbar level (L3/L4). Electrical pain thresholds were lower (P < 0.001) and pain ratings were higher for fascia compared with muscle stimulation (P < 0.05). For both tissues, pain ratings increased significantly across the five 100 Hz trains (from 15 to 22 numerical rating scale for fascia, from 8 to 12 numerical rating scale for muscle; both P < 0.01). Fascia HFS increased fascia pain ratings 2.17 times compared with the unconditioned control site (P < 0.001), but had no significant effect on pain sensitivity of the muscle. The HFS in muscle had no significant effect on muscle pain, but decreased pain sensitivity of the overlying fascia by 20% (P < 0.05). In additional experiments using the same electrodes and followed over >60 minutes post-HFS, potentiation by fascia HFS was similar to that of skin HFS. These findings show that the spinal input from the fascia can induce long-term changes in pain sensitivity for at least 60 minutes making it a candidate potentially contributing to nonspecific low back pain.

HYPNOTIZABILITY AND PAIN MODULATION: A Body-Mind Perspective.

PubMed

Varanini, Maurizio; Balocchi, Rita; Carli, Giancarlo; Paoletti, Giulia; Santarcangelo, Enrica L

2018-01-01

The study investigated whether the cardiac activity and cognitive-emotional traits sustained by the behavioral inhibition/activation system (BIS/BAS) may contribute to hypnotizability-related pain modulation. Nociceptive stimulation (cold-pressor test) was administered to healthy participants with high (highs) and low (lows) hypnotizability in the presence and absence of suggestions for analgesia. Results showed that heart rate increased abruptly at the beginning of nociceptive stimulation in all participants. Then, only in highs heart rate decreased for the entire duration of hand immersion. During stimulation with suggestions of analgesia, pain threshold negatively correlated with heart rate. BIS/BAS activity partially accounted for the observed hypnotizability-related differences in the relation between cardiac interoception and pain experience.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty.

PubMed

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre; Vaes, Peter

2014-01-01

To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

Pulsed laser versus electrical energy for peripheral nerve stimulation

PubMed Central

Wells, Jonathon; Konrad, Peter; Kao, Chris; Jansen, E. Duco; Mahadevan-Jansen, Anita

2010-01-01

Transient optical neural stimulation has previously been shown to elicit highly controlled, artifact-free potentials within the nervous system in a non-contact fashion without resulting in damage to tissue. This paper presents the physiologic validity of elicited nerve and muscle potentials from pulsed laser induced stimulation of the peripheral nerve in a comparative study with the standard method of electrically evoked potentials. Herein, the fundamental physical properties underlying the two techniques are contrasted. Key laser parameters for efficient optical stimulation of the peripheral nerve are detailed. Strength response curves are shown to be linear for each stimulation modality, although fewer axons can be recruited with optically evoked potentials. Results compare the relative transient energy requirements for stimulation using each technique and demonstrate that optical methods can selectively excite functional nerve stimulation. Adjacent stimulation and recording of compound nerve potentials in their entirety from optical and electrical stimulation are presented, with optical responses shown to be free of any stimulation artifact. Thus, use of a pulsed laser exhibits some advantages when compared to standard electrical means for excitation of muscle potentials in the peripheral nerve in the research domain and possibly for clinical diagnostics in the future. PMID:17537515

Improving executive function using transcranial infrared laser stimulation

PubMed Central

Blanco, Nathaniel J.; Maddox, W. Todd; Gonzalez-Lima, F.

2015-01-01

Transcranial infrared laser stimulation is a new non-invasive form of low-level light therapy that may have a wide range of neuropsychological applications. It entails using low-power and high-energy density infrared light from lasers to increase metabolic energy. Preclinical work showed that this intervention can increase cortical metabolic energy, thereby improving frontal cortex-based memory function in rats. Barrett & Gonzalez-Lima (2013) discovered that transcranial laser stimulation can enhance sustained attention and short-term memory in humans. We extend this line of work to executive function. Specifically, we ask whether transcranial laser stimulation enhances performance in the Wisconsin Card Sorting Task (WCST) that is considered the gold-standard of executive function and is compromised in normal aging and a number of neuropsychological disorders. We used a laser of a specific wavelength (1064 nm) that photostimulates cytochrome oxidase—the enzyme catalyzing oxygen consumption for metabolic energy production. Increased cytochrome oxidase activity is considered the primary mechanism of action of this intervention. Participants who received laser treatment made fewer errors and showed improved set-shifting ability relative to placebo controls. These results suggest that transcranial laser stimulation improves executive function and may have exciting potential for treating or preventing deficits resulting from neuropsychological disorders or normal aging. PMID:26017772

Improving executive function using transcranial infrared laser stimulation.

PubMed

Blanco, Nathaniel J; Maddox, W Todd; Gonzalez-Lima, Francisco

2017-03-01

Transcranial infrared laser stimulation is a new non-invasive form of low-level light therapy that may have a wide range of neuropsychological applications. It entails using low-power and high-energy-density infrared light from lasers to increase metabolic energy. Preclinical work showed that this intervention can increase cortical metabolic energy, thereby improving frontal cortex-based memory function in rats. Barrett and Gonzalez-Lima (2013, Neuroscience, 230, 13) discovered that transcranial laser stimulation can enhance sustained attention and short-term memory in humans. We extend this line of work to executive function. Specifically, we ask whether transcranial laser stimulation enhances performance in the Wisconsin Card Sorting Task that is considered the gold standard of executive function and is compromised in normal ageing and a number of neuropsychological disorders. We used a laser of a specific wavelength (1,064 nm) that photostimulates cytochrome oxidase - the enzyme catalysing oxygen consumption for metabolic energy production. Increased cytochrome oxidase activity is considered the primary mechanism of action of this intervention. Participants who received laser treatment made fewer errors and showed improved set-shifting ability relative to placebo controls. These results suggest that transcranial laser stimulation improves executive function and may have exciting potential for treating or preventing deficits resulting from neuropsychological disorders or normal ageing. © 2015 The British Psychological Society.

Spinal Cord Stimulation for the Relief of Pain: Proceedings of a Symposium during the 4th International Congress of the International Neuromodulation Society, September 16-20, 1998, Lucerne, Switzerland.

PubMed

Oakley, J C

1999-07-01

Spinal cord stimulation has become an accepted technique used in the management of chronic neuropathic pain syndromes. However, a number of problematic questions remain unanswered. This introduction states some of these problems and concentrates on the problem of whether low back pain can be relieved by stimulation. This paper introduces subsequent contributions to this symposium, which offer some interesting new techniques, and attempts to answer some of the problems presented.

From pulses to pain relief: an update on the mechanisms of rTMS-induced analgesic effects.

PubMed

Moisset, X; de Andrade, D C; Bouhassira, D

2016-05-01

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique that allows cortical stimulation. Recent studies have shown that rTMS of the primary motor cortex or dorsolateral prefrontal cortex decreases pain in various pain conditions. The aim of this review was to summarize the main characteristics of rTMS-induced analgesic effects and to analyse the current data on its mechanisms of action. Medline, PubMed and Web of Science were searched for studies on the analgesic effects and mechanisms of rTMS-induced analgesic effects. Studies on epidural motor cortex stimulation (EMCS) were also included when required, as several mechanisms of action are probably shared between both techniques. Stimulation site and stimulation parameters have a major impact on rTMS-related analgesic effects. Local cortical stimulation is able to elicit changes in the functioning of distant brain areas. These modifications outlast the duration of the rTMS session and probably involve LTP-like mechanisms via its influence on glutamatergic networks. Analgesic effects seem to be correlated to restoration of normal cortical excitability in chronic pain patients and depend on pain modulatory systems, in particular endogenous opioids. Dopamine, serotonin, norepinephrine and GABAergic circuitry may also be involved in its effects, as well as rostrocaudal projections. rTMS activates brain areas distant from the stimulation site. LTP-like mechanisms, dependence on endogenous opioids and increase in concentration of neurotransmitters (monoamines, GABA) have all been implicated in its analgesic effects, although more studies are needed to fill in the still existing gaps in the understanding of its mechanisms of action. © 2015 European Pain Federation - EFIC®

Patient-conducted anodal transcranial direct current stimulation of the motor cortex alleviates pain in trigeminal neuralgia

PubMed Central

2014-01-01

Background Transcranial direct current stimulation (tDCS) of the primary motor cortex has been shown to modulate pain and trigeminal nociceptive processing. Methods Ten patients with classical trigeminal neuralgia (TN) were stimulated daily for 20 minutes over two weeks using anodal (1 mA) or sham tDCS over the primary motor cortex (M1) in a randomized double-blind cross-over design. Primary outcome variable was pain intensity on a verbal rating scale (VRS 0–10). VRS and attack frequency were assessed for one month before, during and after tDCS. The impact on trigeminal pain processing was assessed with pain-related evoked potentials (PREP) and the nociceptive blink reflex (nBR) following electrical stimulation on both sides of the forehead before and after tDCS. Results Anodal tDCS reduced pain intensity significantly after two weeks of treatment. The attack frequency reduction was not significant. PREP showed an increased N2 latency and decreased peak-to-peak amplitude after anodal tDCS. No severe adverse events were reported. Conclusion Anodal tDCS over two weeks ameliorates intensity of pain in TN. It may become a valuable treatment option for patients unresponsive to conventional treatment. PMID:25424567

A Simple fMRI Compatible Robotic Stimulator to Study the Neural Mechanisms of Touch and Pain.

PubMed

Riillo, F; Bagnato, C; Allievi, A G; Takagi, A; Fabrizi, L; Saggio, G; Arichi, T; Burdet, E

2016-08-01

This paper presents a simple device for the investigation of the human somatosensory system with functional magnetic imaging (fMRI). PC-controlled pneumatic actuation is employed to produce innocuous or noxious mechanical stimulation of the skin. Stimulation patterns are synchronized with fMRI and other relevant physiological measurements like electroencephalographic activity and vital physiological parameters. The system allows adjustable regulation of stimulation parameters and provides consistent patterns of stimulation. A validation experiment demonstrates that the system safely and reliably identifies clusters of functional activity in brain regions involved in the processing of pain. This new device is inexpensive, portable, easy-to-assemble and customizable to suit different experimental requirements. It provides robust and consistent somatosensory stimulation, which is of crucial importance to investigating the mechanisms of pain and its strong connection with the sense of touch.

High-Definition Transcranial Direct Current Stimulation Enhances Conditioned Pain Modulation in Healthy Volunteers: A Randomized Trial.

PubMed

Flood, Andrew; Waddington, Gordon; Cathcart, Stuart

2016-05-01

Transcranial direct current stimulation (tDCS) is a form of brain stimulation that allows for the selective increase or decrease in the cortical excitability of a targeted region. When applied over the motor cortex it has been shown to induce changes in cortical and subcortical brain regions involved in descending pain inhibition or conditioned pain modulation (CPM). The aim of the current study was to assess whether activation of pain inhibitory pathways via tDCS of the motor cortex facilitates the CPM response. Elevated CPM after active tDCS of the motor cortex was hypothesized. Thirty healthy male volunteers attended 2 experimental sessions separated by 7 days. Both sessions consisted of CPM assessment after 20 minutes of either active or sham (placebo) tDCS over the motor cortex. CPM capacity was assessed via the pain-inhibits-pain protocol; CPM responses were shown to be elevated after active compared with sham tDCS. This report concludes that tDCS of the motor cortex enhances the CPM response in healthy men. This finding supports the potential utility of tDCS interventions in clinical pain treatment. The use of noninvasive brain stimulation over the motor cortex was shown to enhance the CPM effect. This finding supports the use of tDCS in the treatment of chronic pain, particularly in sufferers exhibiting maladaptive CPM. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Nanosecond UV lasers stimulate transient Ca2+ elevations in human hNT astrocytes.

PubMed

Raos, B J; Graham, E S; Unsworth, C P

2017-06-01

Astrocytes respond to various stimuli resulting in intracellular Ca 2+ signals that can propagate through organized functional networks. Recent literature calls for the development of techniques that can stimulate astrocytes in a fast and highly localized manner to emulate more closely the characteristics of astrocytic Ca 2+ signals in vivo. In this article we demonstrate, for the first time, how nanosecond UV lasers are capable of reproducibly stimulating Ca 2+ transients in human hNT astrocytes. We report that laser pulses with a beam energy of 4-29 µJ generate transient increases in cytosolic Ca 2+ . These Ca 2+ transients then propagate to adjacent astrocytes as intercellular Ca 2+ waves. We propose that nanosecond laser stimulation provides a valuable tool for enabling the study of Ca 2+ dynamics in human astrocytes at both a single cell and network level. Compared to previously developed techniques nanosecond laser stimulation has the advantage of not requiring loading of photo-caged or -sensitising agents, is non-contact, enables stimulation with a high spatiotemporal resolution and is comparatively cost effective.

Transcutaneous electrical nerve stimulation effect on postoperative complications.

PubMed

Sezen, Celal Bugra; Akboga, Suleyman Anil; Celik, Ali; Kalafat, Cem Emrah; Tastepe, Abdullah Irfan

2017-05-01

Objectives Transcutaneous electrical nerve stimulation has been used to control post-thoracotomy pain, with conflicting results. We aimed to assess its efficacy on post-thoracotomy pain and early complications. Methods Between January 2012 and December 2014, 87 patients underwent a standard posterolateral thoracotomy and were randomized in 2 groups: group T was 43 patients who had transcutaneous electrical nerve stimulation and group C was 44 patients who had placebo stimulation with an inoperative device. Pain score was measured using a visual analogue scale ranging from 0 to 10. The frequency of the device was set at 100 Hz and pulse width at 100 ms. Results There were no statistically significant differences in the demographic characteristics of the 2 groups, and there was no difference in the duration of hospitalization (4.74 ± 1.6 vs. 5.23 ± 1.5 days; p = 0.06). Postoperative pain scores of the two groups showed that on postoperative day 0, 1, and 2, the mean pain scores of group T were significantly lower ( p = 0.001, p < 0.001, and p = 0.003). There were no significant differences in early complications or surgical technique. Conclusion We concluded that electrical stimulation is a safe and effective adjunctive therapy for acute post-thoracotomy pain control. However, it does not affect the duration of hospitalization or early pulmonary complications.

Some Non-FDA Approved Uses for Neuromodulation: A Review of the Evidence.

PubMed

Lee, Samuel; Abd-Elsayed, Alaa

2016-09-01

Neuromodulation, including spinal cord stimulation and peripheral nerve field stimulation, has been used with success in treating several painful conditions. The FDA approved the use of neuromodulation for a few indications. We review evidence for neuromodulation in treating some important painful conditions that are not currently FDA approved. This review included an online web search for only clinical trials testing the efficacy of neuromodulation in treating coronary artery disease, peripheral vascular disease (PVD), headache, and peripheral field stimulation. Our systematic literature search found 10, 6, and 3 controlled studies relating to coronary artery disease, PVD, and headache, respectively. Our review also included 5 noncontrolled studies relating to peripheral field stimulation, as no controlled studies had been completed. This review article shows compelling evidence based on clinical trials that neuromodulation can be of benefit for patients with serious painful conditions that are not currently approved by the FDA. © 2015 World Institute of Pain.

Fluid mechanics in dentinal microtubules provides mechanistic insights into the difference between hot and cold dental pain.

PubMed

Lin, Min; Luo, Zheng Yuan; Bai, Bo Feng; Xu, Feng; Lu, Tian Jian

2011-03-23

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not "equally sensitive" to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices.

Fluid Mechanics in Dentinal Microtubules Provides Mechanistic Insights into the Difference between Hot and Cold Dental Pain

PubMed Central

Lin, Min; Luo, Zheng Yuan; Bai, Bo Feng; Xu, Feng; Lu, Tian Jian

2011-01-01

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not “equally sensitive” to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices. PMID:21448459

Dry cupping for plantar fasciitis: a randomized controlled trial.

PubMed

Ge, Weiqing; Leson, Chelsea; Vukovic, Corey

2017-05-01

[Purpose] The purpose of this study was to determine the effects of dry cupping on pain and function of patients with plantar fasciitis. [Subjects and Methods] Twenty-nine subjects (age 15 to 59 years old, 20 females and 9 males), randomly assigned into the two groups (dry cupping therapy and electrical stimulation therapy groups), participated in this study. The research design was a randomized controlled trial (RCT). Treatments were provided to the subjects twice a week for 4 weeks. Outcome measurements included the Visual Analogue Pain Scale (VAS) (at rest, first in the morning, and with activities), the Foot and Ankle Ability Measure (FAAM), the Lower Extremity Functional Scale (LEFS), as well as the pressure pain threshold. [Results]The data indicated that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function significantly in the population tested, as all the 95% Confidence Intervals (CIs) did not include 0 except for the pressure pain threshold. There was no significant difference between the dry cupping therapy and electrical stimulation groups in all the outcome measurements. [Conclusion] These results support that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function in the population tested.

Dry cupping for plantar fasciitis: a randomized controlled trial

PubMed Central

Ge, Weiqing; Leson, Chelsea; Vukovic, Corey

2017-01-01

[Purpose] The purpose of this study was to determine the effects of dry cupping on pain and function of patients with plantar fasciitis. [Subjects and Methods] Twenty-nine subjects (age 15 to 59 years old, 20 females and 9 males), randomly assigned into the two groups (dry cupping therapy and electrical stimulation therapy groups), participated in this study. The research design was a randomized controlled trial (RCT). Treatments were provided to the subjects twice a week for 4 weeks. Outcome measurements included the Visual Analogue Pain Scale (VAS) (at rest, first in the morning, and with activities), the Foot and Ankle Ability Measure (FAAM), the Lower Extremity Functional Scale (LEFS), as well as the pressure pain threshold. [Results]The data indicated that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function significantly in the population tested, as all the 95% Confidence Intervals (CIs) did not include 0 except for the pressure pain threshold. There was no significant difference between the dry cupping therapy and electrical stimulation groups in all the outcome measurements. [Conclusion] These results support that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function in the population tested. PMID:28603360

Stimulation of the cochlea using green laser light

NASA Astrophysics Data System (ADS)

Wenzel, G. I.; Balster, S.; Lim, H. H.; Zhang, K.; Reich, U.; Lubatschowski, H.; Ertmer, W.; Lenarz, T.; Reuter, G.

2009-02-01

The success of conventional hearing aids and electrical cochlear implants have generally been limited to hearing in quiet situations, in part due to a lack of localized (i.e., frequency specificity) sensorineural activation and subsequent impaired speech discrimination in noise. Laser light is a source of energy that can be focused in a controlled manner and may provide more localized activation of the inner ear, the cochlea. Compound action potentials have been elicited using 2.12 µm laser pulses through activation of auditory nerve fibers (Izzo et al. 2006). Laser stimulation (813 nm) of the cochlea has shown to induce basilar membrane motion and cochlear microphonic potentials (Fridberger et al. 2006). We sought to assess if visible light (green, 532 nm, 10 ns pulses) could be used to consistently activate the cochlea. The laser parameters were selected based on our initial attempt to induce an optoacoustic effect as the energy transfer mechanism to the cochlea. Click evoked auditory brainstem responses (AABRs) were recorded preoperatively in ketamine-anesthetized guinea pigs to confirm normal hearing. The bulla and then the cochlea were exposed. Optically evoked ABRs (OABR) were recorded in response to laser stimulation with a 50 µm optical fiber (532 nm, 10 ns pulses, 500 repetitions, 10 pulses/s; Nd:YAG laser) at the round window (RW) directed towards the basilar membrane (BM). OABRs similar in morphology to acoustically evoked ABRs, except for shorter latencies, were obtained for stimulation through the RW with energy levels between 1.7-30 µJ/pulse. The OABRs increased with increasing energy level reaching a saturation level around 13-15 µJ/pulse. Furthermore the responses remained consistent across stimulation over time, including stimulation at 13 µJ/pulse for over 30 minutes, indicating minimal or no damage within the cochlea with this type of laser stimulation. Overall we have demonstrated that laser light stimulation with 532 nm has potential for a new type of auditory prosthesis that can activate the cochlea without any apparent functional damage. Further studies are needed to determine the optimal laser parameters and fiber placement locations for localized and tonotopic activation.

Dissociable Effects of the Cannabinoid Receptor Agonists Δ9-Tetrahydrocannabinol and CP55940 on Pain-Stimulated Versus Pain-Depressed Behavior in Rats

PubMed Central

Kwilasz, Andrew J.

2012-01-01

Cannabinoid receptor agonists produce reliable antinociception in most preclinical pain assays but have inconsistent analgesic efficacy in humans. This disparity suggests that conventional preclinical assays of nociception are not sufficient for the prediction of cannabinoid effects related to clinical analgesia. To extend the range of preclinical cannabinoid assessment, this study compared the effects of the marijuana constituent and low-efficacy cannabinoid agonist Δ9-tetrahydrocannabinol (THC) and the high-efficacy synthetic cannabinoid agonist 3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol (CP55940) in assays of pain-stimulated and pain-depressed behavior. Intraperitoneal injection of dilute lactic acid (1.8% in 1 ml/kg) stimulated a stretching response or depressed intracranial self-stimulation (ICSS) in separate groups of male Sprague-Dawley rats. THC (0.1–10 mg/kg) and CP55940 (0.0032–0.32 mg/kg) dose-dependently blocked acid- stimulated stretching but only exacerbated acid-induced depression of ICSS at doses that also decreased control ICSS in the absence of a noxious stimulus. Repeated THC produced tolerance to sedative rate-decreasing effects of THC on control ICSS in the absence of the noxious stimulus but failed to unmask antinociception in the presence of the noxious stimulus. THC and CP55940 also failed to block pain-related depression of feeding in rats, although THC did attenuate satiation-related depression of feeding. In contrast to the effects of the cannabinoid agonists, the clinically effective analgesic and nonsteroidal anti-inflammatory drug ketoprofen (1 mg/kg) blocked acid-stimulated stretching and acid-induced depression of both ICSS and feeding. The poor efficacy of THC and CP55940 to block acute pain-related depression of behavior in rats agrees with the poor efficacy of cannabinoids to treat acute pain in humans. PMID:22892341

WITHDRAWN: Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

PubMed

Gadsby, J G; Flowerdew, M W

2007-07-18

In view of the claims and counter-claims of the effectiveness of transcutaneous electrical nerve stimulation, it would seem appropriate to systematically review the literature. To determine the effectiveness of transcutaneous electrical nerve stimulation in reducing pain and improving range of movement in patients with chronic low back pain. Electronic searches of EMBASE, MEDLINE, CISCOM, AMED for all studies of TENS in the English language, identifying those treating chronic low back pain and hand searching their references. The inclusion criterion for studies included in this review, 6 of 68 identified, was comparisons of TENS/ALTENS versus placebo in patients with chronic low back pain. Outcome data on pain reduction, range of movement, functional status and work was extracted by two independent reviewers together with trial design qualities to construct a Quality Index. The ratio of odds of improvement in pain for each comparison was calculated: TENS vs. placebo at 1.62 (95% CI 0.90, 2.68); ALTENS vs. placebo at 7.22 (95% CI 2.60, 20.01) and TENS/ALTENS vs. placebo at 2.11 (95% CI 1.32, 3.38) times that of placebo. An improvement in pain reduction was seen in 45.80% (CI 37.00%, 55.00%) of TENS; 86.70% (CI 80.00%, 93.00%) of ALTENS; 54.00% (CI 46.20%, 61.80%) of TENS/ ALTENS and 36.40% (95%CI 28.40%, 44.40%) of placebo subjects. The odds of improvement in range of movement on ALTENS vs. placebo was 6.61 times (95% CI 2.36, 18.55) that of placebo. Transcutaneous electrical nerve stimulation appears to reduce pain and improve the range of movement in chronic low back pain subjects. A definitive randomised controlled study of ALTENS, TENS, placebo/no treatment controls, of sufficient power, is needed to confirm these findings.

Responses of human sensory characteristics to 532 nm pulse laser stimuli.

PubMed

Kim, Ji-Sun; Oh, Han-Byeol; Kim, A-Hee; Kim, Jun-Sik; Lee, Eun-Suk; Goh, Bong-Jun; Kim, Jae-Young; Jang, Kyungmin; Park, Jong-Rak; Chung, Soon-Cheol; Jun, Jae-Hoon

2016-04-29

Lasers are advantageous in some applications to stimulate a small target area and is used in various fields such as optogenetic, photoimmunological and neurophysiological studies. This study aims to implement a non-contact sense of touch without damaging biological tissues using laser. Various laser parameters were utilized in safety range to induce a sense of touch and investigate the human responses. With heat distribution simulation, the amount of changes in the temperature and the tendency in laser parameters of sensory stimulation were analyzed. The results showed the identified tactile responses in safety range with various laser parameters and temperature distribution for the laser stimulus was obtained through the simulation. This study can be applied to the areas of sensory receptor stimulation, neurophysiology and clinical medicine.

Effect of pulsed electromagnetic field therapy on experimental pain: A double-blind, randomized study in healthy young adults.

PubMed

Beaulieu, Karen; Beland, Patricia; Pinard, Marilee; Handfield, Guilène; Handfield, Nicole; Goffaux, Philippe; Corriveau, Hélène; Léonard, Guillaume

2016-01-01

Previous studies suggested that pulsed electromagnetic field (PEMF) therapy can decrease pain. To date, however, it remains difficult to determine whether the analgesic effect observed in patients are attributable to a direct effect of PEMF on pain or to an indirect effect of PEMF on inflammation and healing. In the present study, we used an experimental pain paradigm to evaluate the direct effect of PEMF on pain intensity, pain unpleasantness, and temporal summation of pain. Twenty-four healthy subjects (mean age 22 ± 2 years; 9 males) participated in the experiment. Both real and sham PEMF were administered to every participant using a randomized, double-blind, cross-over design. For each visit, PEMF was applied for 10 minutes on the right forearm using a portable device. Experimental pain was evoked before (baseline) and after PEMF with a 9 cm(2) Pelletier-type thermode, applied on the right forearm (120 s stimulation; temperature individually adjusted to produce moderate baseline pain). Pain intensity and unpleasantness were evaluated using a 0-100 numerical pain rating scale. Temporal summation was evaluated by comparing pain intensity ratings obtained at the end of tonic nociceptive stimulation (120 s) with pain intensity ratings obtained after 60 s of stimulation. When compared to baseline, there was no change in pain intensity and unpleasantness following the application of real or sham PEMF. PEMF did not affect temporal summation. The present observations suggest that PEMF does not directly influence heat pain perception in healthy individuals.

Validation of a New Placebo Interferential Current Method: A New Placebo Method of Electrostimulation.

PubMed

Mendonça Araújo, Fernanda; Alves Menezes, Mayara; Martins de Araújo, Ariane; Abner Dos Santos Sousa, Thiago; Vasconcelos Lima, Lucas; Ádan Nunes Carvalho, Elyson; Melo DeSantana, Josimari

2017-01-01

The present study aimed to investigate if a new placebo device for interferential current (IFC) that delivers current during only the first 40 seconds of stimulation is effective at promoting adequate subject blinding. Seventy-five subjects were recruited and enrolled into three groups: active IFC, inactive placebo, and new placebo. Pressure pain threshold (PPT), cutaneous sensory threshold (CST), and pain intensity were measured before and after the intervention. After the final assessment, the subjects and the investigator who applied the current were asked about the type of stimulation administered. None of the placebo forms studied resulted in significant changes to PPT, CST, or pain intensity. The subjects stimulated with active IFC at high intensities (> 17 mA) of stimulation showed higher PPT and CST and lower pain intensity than subjects stimulated at low intensities ( p < 0.03). The new placebo method blinded the investigator in 100% of cases of IFC and 60% of subjects stimulated, whereas for inactive placebo, the investigator was blinded at a rate of 0% and 34% of subjects. The new method of placebo IFC was effective for blinding of research investigators and most of the active IFC-treated subjects, promoting an appropriate placebo method. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Low level laser therapy for patients with cervical disk hernia.

PubMed

Takahashi, Hiroshi; Okuni, Ikuko; Ushigome, Nobuyuki; Harada, Takashi; Tsuruoka, Hiroshi; Ohshiro, Toshio; Sekiguchi, Masayuki; Musya, Yoshiro

2012-09-30

In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic shoulder joint pain, elbow, hand and finger pain, and low back pain. The present study is a report on the effects of LLLT for chronic neck pain. Over a 3 year period, 26 rehabilitation department outpatients with chronic neck pain, diagnosed as being caused by cervical disk hernia, underwent treatment applied to the painful area with a 1000 mW semi-conductor laser device delivering at 830 nm in continuous wave, 20.1 J/cm(2)/point, and three shots were given per session (1 treatment) with twice a week for 4 weeks. 1. A visual analogue scale (VAS) was used to determine the effects of LLLT for chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). 2. After treatment, no significant differences in cervical spine range of motion were observed. 3. Discussions with the patients revealed that in order to receive continued benefits from treatment, it was important for them to be taught how to avoid postures that would cause them neck pain in everyday life. The present study demonstrates that LLLT was an effective form of treatment for neck and back pain caused by cervical disk hernia, reinforced by postural training.

Laser radiation in tennis elbow treatment: a new minimally invasive alternative

NASA Astrophysics Data System (ADS)

Paganini, Stefan; Thal, Dietmar R.; Werkmann, Klaus

1998-01-01

The epicondylitis humeri radialis (EHR) (tennis elbow), is a common disease in elbow joint pain syndromes. We treated patients with chronic pain for at least one year and no improvement with conservative or operative therapies with a new minimal invasive method, the EHR-Laser radiation (EHR- LR). With this method periepicondylar coagulations were applied to the trigger points of the patients. For this the previously established technique of facet joint coagulation with the Nd:Yag-laser was modified. In a follow-up study of between 6 weeks and 2 years all patients reported either a significant pain reduction or were symptom free. EHR-LR is a new method situated between conservative and surgical treatments for minimal invasive therapy of EHR. Several therapeutic rationales were discussed for the resulting pain reduction.

Transcutaneous electrical nerve stimulation and interferential current demonstrate similar effects in relieving acute and chronic pain: a systematic review with meta-analysis.

PubMed

Almeida, Camila Cadena de; Silva, Vinicius Z Maldaner da; Júnior, Gerson Cipriano; Liebano, Richard Eloin; Durigan, Joao Luiz Quagliotti

2018-02-02

Transcutaneous electrical nerve stimulation and interferential current have been widely used in clinical practice. However, a systematic review comparing their effects on pain relief has not yet been performed. To investigate the effects of transcutaneous electrical nerve stimulation and interferential current on acute and chronic pain. We use Pubmed, Embase, LILACS, PEDro and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers that selected studies according to inclusion criteria, extracted information of interest and verified the methodological quality of the studies made study selection. The studies were selected if transcutaneous electrical nerve stimulation and interferential current were used as treatment and they had pain as the main outcome, as evaluated by a visual analog scale. Secondary outcomes were the Western Ontario Macmaster and Rolland Morris Disability questionnaires, which were added after data extraction. Eight studies with a pooled sample of 825 patients were included. The methodological quality of the selected studies was moderate, with an average of six on a 0-10 scale (PEDro). In general, both transcutaneous electrical nerve stimulation and interferential current improved pain and functional outcomes without a statistical difference between them. Transcutaneous electrical nerve stimulation and interferential current have similar effects on pain outcome The low number of studies included in this meta-analysis indicates that new clinical trials are needed. Copyright © 2018 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Is Transcranial Direct Current Stimulation an Effective Predictor for Invasive Occipital Nerve Stimulation Treatment Success in Fibromyalgia Patients?

PubMed

Plazier, Mark; Tchen, Stephanie; Ost, Jan; Joos, Kathleen; De Ridder, Dirk; Vanneste, Sven

2015-10-01

Fibromyalgia is a disorder distinguished by pervasive musculoskeletal pain that has pervasive effects on affected individuals magnifying the importance of finding a safe and viable treatment option. The goal of this study is to investigate if transcranial direct current stimulation (tDCS) treatment can predict the outcome of occipital nerve field stimulation (ONFS) via a subcutaneous electrode. Nine patients with fibromyalgia were selected fulfilling the American College of Rheumatology-90 criteria. The patients were implanted with a subcutaneous trial-lead in the C2 dermatome innervated by the occipital nerve. After the treatment phase of ONFS using a C2 implant, each patient participated in three sessions of tDCS. Stimulation outcomes for pain suppression were examined between the two methods to determine possible correlations. Positive correlation of stimulation effect was noted between the numeric rating scale changes for pain obtained by tDCS treatments and short-term measures of ONFS, but no correlation was noted between tDCS and long-term ONFS outcomes. A correlation also was noted between short-term ONS C2 implant pain suppression and long-term ONS C2 implant treatment success. This pilot study suggests that tDCS is a predictive measure for success of OFNS in short-term but cannot be used as a predictive measure for success of long-term OFNS. Our data confirm previous findings that ONFS via an implanted electrode can improve fibromyalgia pain in a placebo-controlled way and exert a long-term pain suppression effect for ONFS via an implanted electrode. © 2015 International Neuromodulation Society.

Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

PubMed

Gadsby, J G; Flowerdew, M W

2000-01-01

Transcutaneous electrical nerve stimulation (TENS), originally based on the gate-control theory of pain, is widely used for the treatment of chronic low back pain. Despite its wide use and theoretical rationale, there appears at first glance little scientific evidence to support its use. This Cochrane review examines the available evidence on TENS for the treatment of chronic back pain through an exhaustive search of the literature. Transcutaneous electrical nerve stimulation (TENS) and acupuncture-like transcutaneous electrical nerve stimulation (ALTENS) for chronic low back pain management have experienced a tremendous growth over the past 25 years. The objective of this review was to assess the effects of TENS and ALTENS for reducing pain and improving function in patients with chronic back pain. We searched MEDLINE up to November 1997, EMBASE from 1985 to September 1995, Amed and Ciscom to January 1995, reference lists of the retrieved articles, proceedings of conferences and contacted investigators in the field. Randomised trials comparing TENS or ALTENS therapy to placebo in patients with chronic low back pain. Two reviewers independently assessed trial quality and extracted data on pain reduction, range of movement, functional and work status. Six trials were included. The trials included 288 participants with an average age range of 45 to 50 years and approximately equal numbers of women and men. The overall odds ratio for improvement in pain for each comparison was: TENS/ALTENS versus placebo 2.11 (95% confidence interval 1.32 to 3. 38), ALTENS versus placebo 7.22 (95% confidence interval 2.60 to 20.01) and TENS versus placebo 1.52 (95% confidence interval 0.90 to 2.58). The odds ration for improvement in range of motion on ALTENS versus placebo was 6.61 (95% confidence interval 2.36 to 18.55). There is evidence from the limited data available that TENS/ALTENS reduces pain and improves range of motion in chronic back pain patients, at least in the short term. A large trial of ALTENS and TENS is needed to confirm these findings.

Prolonged Reduction in Shoulder Strength after Transcutaneous Electrical Nerve Stimulation Treatment of Exercise-Induced Acute Muscle Pain.

PubMed

Butera, Katie A; George, Steven Z; Borsa, Paul A; Dover, Geoffrey C

2018-03-05

Transcutaneous electrical nerve stimulation (TENS) is commonly used for reducing musculoskeletal pain to improve function. However, peripheral nerve stimulation using TENS can alter muscle motor output. Few studies examine motor outcomes following TENS in a human pain model. Therefore, this study investigated the influence of TENS sensory stimulation primarily on motor output (strength) and secondarily on pain and disability following exercise-induced delayed-onset muscle soreness (DOMS). Thirty-six participants were randomized to a TENS treatment, TENS placebo, or control group after completing a standardized DOMS protocol. Measures included shoulder strength, pain, mechanical pain sensitivity, and disability. TENS treatment and TENS placebo groups received 90 minutes of active or sham treatment 24, 48, and 72 hours post-DOMS. All participants were assessed daily. A repeated measures analysis of variance and post-hoc analysis indicated that, compared to the control group, strength remained reduced in the TENS treatment group (48 hours post-DOMS, P < 0.05) and TENS placebo group (48 hours post-DOMS, P < 0.05; 72 hours post-DOMS, P < 0.05). A mixed-linear modeling analysis was conducted to examine the strength (motor) change. Randomization group explained 5.6% of between-subject strength variance (P < 0.05). Independent of randomization group, pain explained 8.9% of within-subject strength variance and disability explained 3.3% of between-subject strength variance (both P < 0.05). While active and placebo TENS resulted in prolonged strength inhibition, the results were nonsignificant for pain. Results indicated that higher pain and higher disability were independently related to decreased strength. Regardless of the impact on pain, TENS, or even the perception of TENS, may act as a nocebo for motor output. © 2018 World Institute of Pain.

Subclinical recurrent neck pain and its treatment impacts motor training-induced plasticity of the cerebellum and motor cortex

PubMed Central

Baarbé, Julianne K.; Yielder, Paul; Haavik, Heidi; Holmes, Michael W. R.

2018-01-01

The cerebellum processes pain inputs and is important for motor learning. Yet, how the cerebellum interacts with the motor cortex in individuals with recurrent pain is not clear. Functional connectivity between the cerebellum and motor cortex can be measured by a twin coil transcranial magnetic stimulation technique in which stimulation is applied to the cerebellum prior to stimulation over the motor cortex, which inhibits motor evoked potentials (MEPs) produced by motor cortex stimulation alone, called cerebellar inhibition (CBI). Healthy individuals without pain have been shown to demonstrate reduced CBI following motor acquisition. We hypothesized that CBI would not reduce to the same extent in those with mild-recurrent neck pain following the same motor acquisition task. We further hypothesized that a common treatment for neck pain (spinal manipulation) would restore reduced CBI following motor acquisition. Motor acquisition involved typing an eight-letter sequence of the letters Z,P,D,F with the right index finger. Twenty-seven neck pain participants received spinal manipulation (14 participants, 18–27 years) or sham control (13 participants, 19–24 years). Twelve healthy controls (20–27 years) also participated. Participants had CBI measured; they completed manipulation or sham control followed by motor acquisition; and then had CBI re-measured. Following motor acquisition, neck pain sham controls remained inhibited (58 ± 33% of test MEP) vs. healthy controls who disinhibited (98 ± 49% of test MEP, P<0.001), while the spinal manipulation group facilitated (146 ± 95% of test MEP, P<0.001). Greater inhibition in neck pain sham vs. healthy control groups suggests that neck pain may change cerebellar-motor cortex interaction. The change to facilitation suggests that spinal manipulation may reverse inhibitory effects of neck pain. PMID:29489878

Determinants of endogenous analgesia magnitude in a diffuse noxious inhibitory control (DNIC) paradigm: do conditioning stimulus painfulness, gender and personality variables matter?

PubMed

Granot, Michal; Weissman-Fogel, Irit; Crispel, Yonathan; Pud, Dorit; Granovsky, Yelena; Sprecher, Elliot; Yarnitsky, David

2008-05-01

Descending modulation of pain can be demonstrated psychophysically by dual pain stimulation. This study evaluates in 31 healthy subjects the association between parameters of the conditioning stimulus, gender and personality, and the endogenous analgesia (EA) extent assessed by diffuse noxious inhibitory control (DNIC) paradigm. Contact heat pain was applied as the test stimulus to the non-dominant forearm, with stimulation temperature at a psychophysical intensity score of 60 on a 0-100 numerical pain scale. The conditioning stimulus was a 60s immersion of the dominant hand in cold (12, 15, 18 degrees C), hot (44 and 46.5 degrees C), or skin temperature (33 degrees C) water. The test stimulus was repeated on the non-dominant hand during the last 30s of the conditioning immersion. EA extent was calculated as the difference between pain scores of the two test stimuli. State and trait anxiety and pain catastrophizing scores were assessed prior to stimulation. EA was induced only for the pain-generating conditioning stimuli at 46.5 degrees C (p=0.011) and 12 degrees C (p=0.003). EA was independent of conditioning pain modality, or personality, but a significant gender effect was found, with greater EA response in males. Importantly, pain scores of the conditioning stimuli were not correlated with EA extent. The latter is based on both our study population, and on additional 82 patients, who participated in another study, in which EA was induced by immersion at 46.5 degrees C. DNIC testing, thus, seems to be relatively independent of the stimulation conditions, making it an easy to apply tool, suitable for wide range applications in pain psychophysics.

Effect of gender and hand laterality on pain processing in human neonates.

PubMed

Ozawa, Mio; Kanda, Katsuya; Hirata, Michio; Kusakawa, Isao; Suzuki, Chieko

2011-01-01

Previous studies in adults have reported that handedness and gender can affect pain perception. However, it is currently unclear when these differences emerge in human development. Therefore, we examined prefrontal responses to pain stimulation among newborns during their first acute pain experience after birth. Forty newborns at 4-6 days postnatal age were observed during clinically required blood sampling while prefrontal activation was measured with near infrared spectroscopy. Blood sampling in this study was the first experience of a procedure involving skin breaking for these infants. We divided subjects into a right-hand stimulation group (n=21) and a left-hand stimulation group (n=19), depending on whether blood was sampled from the right or the left hand. A three-way analysis of variance (ANOVA) was conducted to examine the effects of several variables on the magnitude of the oxy-Hb value in response to pain stimulus, including stimulus side (right hand or left hand), gender (male or female), recording side (right prefrontal area or left prefrontal area) and interactions between these variables. The data revealed a significant effect of stimulus side (F (1, 72)=9.892, P=0.002), showing that the right-hand stimulation induced a greater prefrontal activation than the left-hand stimulation. No significant gender difference or interactions were found. Our findings suggest that hand laterality affects pain perception even in neonates. However, gender differences in pain perception did not appear to occur during the neonatal period. Further investigations using brain-imaging techniques are required to identify laterality- or gender-related differences in pain processing in humans. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold.

PubMed

Karasuno, Hiroshi; Ogihara, Hisayoshi; Morishita, Katsuyuki; Yokoi, Yuka; Fujiwara, Takayuki; Ogoma, Yoshiro; Abe, Koji

2016-04-01

[Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion.

Experiences of Living with Pain after a Spinal Cord Injury

DTIC Science & Technology

2014-09-01

guess that’s, the, the different things that do work with the pain they don’t you know they don’t cover. Like you said the massage therapy and, and um...change of position, massage , thermal and electrical stimulation, meditation and music. Despite multiple pharmacological treatment options, pain is...pain I do not agree 0 1 2 3 4 5 6 7 8 9 10 I completely agree 7. I (or my caregiver) often use massage , heat or electrical stimulation

Dysregulation of the Descending Pain System in Temporomandibular Disorders Revealed by Low-Frequency Sensory Transcutaneous Electrical Nerve Stimulation: A Pupillometric Study

PubMed Central

Monaco, Annalisa; Cattaneo, Ruggero; Mesin, Luca; Ortu, Eleonora; Giannoni, Mario; Pietropaoli, Davide

2015-01-01

Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the descending pain system may be involved in TMD. PMID:25905862

Treatment of Gingival Hyperpigmentation by Diode Laser for Esthetical Purposes

PubMed Central

El Shenawy, Hanaa M.; Nasry, Sherine A.; Zaky, Ahmed A.; Quriba, Mohamed A. A.

2015-01-01

BACKGROUND: Gingival hyperpigmentation is a common esthetical concern in patients with gummy smile or excessive gingival display. Laser ablation has been recognized recently as the most effective, pleasant and reliable technique. It has the advantage of easy handling, short treatment time, hemostasis, decontamination, and sterilization effect. AIM: In the present study we wanted to explore the efficacy of a 980 nm wavelength diode laser in gingival depigmentation clinically by using both VAS and digital imaging method as means of assessment. METHODS: Diode laser ablation was done for 15 patients who requested cosmetic therapy for melanin pigmented gums. The laser beam delivered by fiberoptic with a diameter of 320 µm, the diode laser system has 980 nm wave lengths and 3 W irradiation powers, in a continuous contact mode in all cases, the entire surface of each pigmented maxillary and mandibular gingiva that required treatment was irradiated in a single session. Clinical examination and digital image analysis were done and the patients were followed up for 3 successive months. RESULTS: There was a statistically significant change in prevalence of bleeding after treatment, as none of the cases showed any signs of bleeding 1 week, 1 month and 3 months after ablation. No statistically significant change was observed in the prevalence of swelling after treatment The VAS evaluation demonstrated that only 4 patients complained of mild pain immediately after the procedure. No pain was perceived from the patients in the rest of the follow up period. There was no statistically significant change in prevalence of pain immediately after treatment compared to pain during treatment. There was a decrease in cases with mild pain after 1 week, 1 month as well as 3 months compared to pain during treatment and immediately after treatment. CONCLUSION: Within the limitations of this study, the use of diode laser was shown to be a safe and effective treatment modality that provides optimal aesthetics with minimal discomfort in patients with gingival hyperpigmentation. PMID:27275269

Remote kinematic training for patients with chronic neck pain: a randomised controlled trial.

PubMed

Sarig Bahat, Hilla; Croft, Kate; Carter, Courtney; Hoddinott, Anna; Sprecher, Elliot; Treleaven, Julia

2018-06-01

To evaluate short- and intermediate-term effects of kinematic training (KT) using virtual reality (VR) or laser in patients with chronic neck pain. A randomised controlled trial with three arms (laser, VR, control) to post-intervention (N = 90), and two arms (laser or VR) continuing to 3 months follow-up. Home training intervention was provided during 4 weeks to VR and laser groups while control group waited. Primary outcome measures included neck disability index (NDI), global perceived effect (GPE), and cervical motion velocity (mean and peak). Secondary outcome measures included pain intensity (VAS), health status (EQ5D), kinesiophobia (TSK), range, smoothness, and accuracy of neck motion as measured by the neck VR system. Measures were taken at baseline, immediately post-training, and 3 months later. Ninety patients with neck pain were randomised to the trial, of which 76 completed 1 month follow-up, and 56 the 3 months follow-up. Significant improvements were demonstrated in NDI and velocity with good effect sizes in intervention groups compared to control. No within-group changes were presented in the control group, compared to global improvements in intervention groups. Velocity significantly improved at both time points in both groups. NDI, VAS, EQ5D, TSK and accuracy significantly improved at both time points in VR and in laser at 3 months evaluation in all but TSK. GPE scores showed 74-84% of participants perceived improvement and/or were satisfied. Significant advantages to the VR group compared to laser were found in velocity, pain intensity, health status and accuracy at both time points. The results support home kinematic training using VR or laser for improving disability, neck pain and kinematics in the short and intermediate term with an advantage to the VR group. The results provide directions for future research, use and development. ACTRN12615000231549.

Design and testing of low intensity laser biostimulator.

PubMed

Valchinov, Emil S; Pallikarakis, Nicolas E

2005-01-13

The non-invasive nature of laser biostimulation has made lasers an attractive alternative in Medical Acupuncture at the last 25 years. However, there is still an uncertainty as to whether they work or their effect is just placebo. Although a plethora of scientific papers published about the topic showing positive clinical results, there is still a lack of objective scientific proofs about the biostimulation effect of lasers in Medical Acupuncture. The objective of this work was to design and build a low cost portable laser device for stimulation of acupuncture points, considered here as small localized biosources (SLB), without stimulating any sensory nerves via shock or heat and to find out a suitable method for objectively evaluating its stimulating effect. The design is aimed for studying SLB potentials provoked by laser stimulus, in search for objective proofs of the biostimulation effect of lasers used in Medical Acupuncture. The proposed biostimulator features two operational modes: program mode and stimulation mode and two output polarization modes: linearly and circularly polarized laser emission. In program mode, different user-defined stimulation protocols can be created and memorized. The laser output can be either continuous or pulse modulated. Each stimulation session consists of a pre-defined number of successive continuous or square pulse modulated sequences of laser emission. The variable parameters of the laser output are: average output power, pulse width, pulse period, and continuous or pulsed sequence duration and repetition period. In stimulation mode the stimulus is automatically applied according to the pre-programmed protocol. The laser source is 30 mW AlGaInP laser diode with an emission wavelength of 685 nm, driven by a highly integrated driver. The optical system designed for beam collimation and polarization change uses single collimating lens with large numerical aperture, linear polarizer and a quarter-wave retardation plate. The proposed method for testing the device efficiency employs a biofeedback from the subject by recording the biopotentials evoked by the laser stimulus at related distant SLB sites. Therefore measuring of SLB biopotentials caused by the stimulus would indicate that a biopotential has been evoked at the irradiated site and has propagated to the measurement sites, rather than being caused by local changes of the electrical skin conductivity. A prototype device was built according to the proposed design using relatively inexpensive and commercially available components. The laser output can be pulse modulated from 0.1 to 1000 Hz with a duty factor from 10 to 90%. The average output power density can be adjusted in the range 24-480 mW/cm2, where the total irradiation is limited to 2 Joule per stimulation session. The device is controlled by an 8-bit RISC Flash microcontroller with internal RAM and EEPROM memory, which allows for a wide range of different stimulation protocols to be implemented and memorized. The integrated laser diode driver with its onboard light power control loop provides safe and consistent laser modulation. The prototype was tested on the right Tri-Heater (TH) acupuncture meridian according to the proposed method. Laser evoked potentials were recorded from most of the easily accessible SLB along the meridian under study. They appear like periodical spikes with a repetition rate from 0.05 to 10 Hz and amplitude range 0.1-1 mV. The prototype's specifications were found to be better or comparable to those of other existing devices. It features low component count, small size and low power consumption. Because of the low power levels used the possibility of sensory nerve stimulation via the phenomenon of shock or heat is excluded. Thus senseless optical stimulation is achieved. The optical system presented offers simple and cost effective way for beam collimation and polarization change. The novel method proposed for testing the device efficiency allows for objectively recording of SLB potentials evoked by laser stimulus. Based on the biopotential records obtained with this method, a scientifically based conclusion can be drawn about the effectiveness of the commercially available devices for low-level laser therapy used in Medical Acupuncture. The prototype tests showed that with the biostimulator presented, SLB could be effectively stimulated at low power levels. However more studies are needed to derive a general conclusion about the SLB biostimulation mechanism of lasers and their most effective power and optical settings.

Altered quantitative sensory testing outcome in subjects with opioid therapy.

PubMed

Chen, Lucy; Malarick, Charlene; Seefeld, Lindsey; Wang, Shuxing; Houghton, Mary; Mao, Jianren

2009-05-01

Preclinical studies have suggested that opioid exposure may induce a paradoxical decrease in the nociceptive threshold, commonly referred as opioid-induced hyperalgesia (OIH). While OIH may have implications in acute and chronic pain management, its clinical features remain unclear. Using an office-based quantitative sensory testing (QST) method, we compared pain threshold, pain tolerance, and the degree of temporal summation of the second pain in response to thermal stimulation among three groups of subjects: those with neither pain nor opioid therapy (group 1), with chronic pain but without opioid therapy (group 2), and with both chronic pain and opioid therapy (group 3). We also examined the possible correlation between QST responses to thermal stimulation and opioid dose, opioid treatment duration, opioid analgesic type, pain duration, or gender in group 3 subjects. As compared with both group 1 (n=41) and group 2 (n=41) subjects, group 3 subjects (n=58) displayed a decreased heat pain threshold and exacerbated temporal summation of the second pain to thermal stimulation. In contrast, there were no differences in cold or warm sensation among three groups. Among clinical factors, daily opioid dose consistently correlated with the decreased heat pain threshold and exacerbated temporal summation of the second pain in group 3 subjects. These results indicate that decreased heat pain threshold and exacerbated temporal summation of the second pain may be characteristic QST changes in subjects with opioid therapy. The data suggest that QST may be a useful tool in the clinical assessment of OIH.

Quantum theory of laser-stimulated desorption

NASA Technical Reports Server (NTRS)

Slutsky, M. S.; George, T. F.

1978-01-01

A quantum theory of laser-stimulated desorption (LSDE) is presented and critically analyzed. It is shown how LSDE depends on laser-pulse characteristics and surface-lattice dynamics. Predictions of the theory for a Debye model of the lattice dynamics are compared to recent experimental results.

Intrathecal Drug Delivery and Spinal Cord Stimulation for the Treatment of Cancer Pain.

PubMed

Xing, Fangfang; Yong, R Jason; Kaye, Alan David; Urman, Richard D

2018-02-05

The purpose of the present investigation is to summarize the body and quality of evidence including the most recent studies in support of intrathecal drug delivery systems and spinal cord stimulation for the treatment of cancer-related pain. In the past 3 years, a number of prospective studies have been published supporting intrathecal drug delivery systems for cancer pain. Additional investigation with adjuvants to morphine-based analgesia including dexmedetomidine and ziconotide support drug-induced benefits of patient-controlled intrathecal analgesia. A study has also been recently published regarding cost-savings for intrathecal drug delivery system compared to pharmacologic management, but an analysis in the Ontario, Canada healthcare system projects additional financial costs. Finally, the Polyanalgesic Consensus Committee has updated its recommendations regarding clinical guidelines for intrathecal drug delivery systems to include new information on dosing, trialing, safety, and systemic opioid reduction. There is still a paucity of clinical evidence for spinal cord stimulation in the treatment of cancer pain. There are new intrathecal drugs under investigation including various conopeptides and AYX1. Large, prospective, modern, randomized controlled studies are still needed to support the use of both intrathecal drug delivery systems as well as spinal cord stimulation for cancer pain populations. There are multiple prospective and small randomized controlled studies that highlight a potential promising future for these interventional modalities. Related to the challenge and urgency of cancer pain, the pain practitioner community is moving toward a multimodal approach that includes discussions regarding the role of intrathecal therapies and spinal cord stimulation to the individualized treatment of patients.

The effect of combined stimulation of external cold and vibration during immunization on pain and anxiety levels in children.

PubMed

Canbulat Şahiner, Nejla; İnal, Sevil; Sevim Akbay, Ayşe

2015-06-01

Procedures involving needles are the most common and major sources of pain in children. External cold and vibration via Buzzy (MMJ Labs, Atlanta, GA) is a method that combines cooling and vibration. This study investigated the effect of the combined stimulation of skin with external cold and vibration via Buzzy on the pain and anxiety levels in children during immunization. This study was a prospective, randomized controlled trial. Children were randomized into two groups: experimental (external cold and Buzzy) and control (no intervention). The pain and anxiety levels of the children were assessed using the Wong-Baker FACES scale and Children Fear Scale. The experimental group showed significantly lower pain and anxiety levels than the control group during immunization. The combined stimulation of skin with external cold and vibration can be used to reduce pain and anxiety during pediatric immunization. Copyright © 2015 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Paresthesia-Independence: An Assessment of Technical Factors Related to 10 kHz Paresthesia-Free Spinal Cord Stimulation.

PubMed

De Carolis, Giuliano; Paroli, Mery; Tollapi, Lara; Doust, Matthew W; Burgher, Abram H; Yu, Cong; Yang, Thomas; Morgan, Donna M; Amirdelfan, Kasra; Kapural, Leonardo; Sitzman, B Todd; Bundschu, Richard; Vallejo, Ricardo; Benyamin, Ramsin M; Yearwood, Thomas L; Gliner, Bradford E; Powell, Ashley A; Bradley, Kerry

2017-05-01

Spinal cord stimulation (SCS) has been successfully used to treat chronic intractable pain for over 40 years. Successful clinical application of SCS is presumed to be generally dependent on maximizing paresthesia-pain overlap; critical to achieving this is positioning of the stimulation field at the physiologic midline. Recently, the necessity of paresthesia for achieving effective relief in SCS has been challenged by the introduction of 10 kHz paresthesia-free stimulation. In a large, prospective, randomized controlled pivotal trial, HF10 therapy was demonstrated to be statistically and clinically superior to paresthesia-based SCS in the treatment of severe chronic low back and leg pain. HF10 therapy, unlike traditional paresthesia-based SCS, requires no paresthesia to be experienced by the patient, nor does it require paresthesia mapping at any point during lead implant or post-operative programming. To determine if pain relief was related to technical factors of paresthesia, we measured and analyzed the paresthesia responses of patients successfully using HF10 therapy. Prospective, multicenter, non-randomized, non-controlled interventional study. Outpatient pain clinic at 10 centers across the US and Italy. Patients with both back and leg pain already implanted with an HF10 therapy device for up to 24 months were included in this multicenter study. Patients provided pain scores prior to and after using HF10 therapy. Each patient's most efficacious HF10 therapy stimulation program was temporarily modified to a low frequency (LF; 60 Hz), wide pulse width (~470 mus), paresthesia-generating program. On a human body diagram, patients drew the locations of their chronic intractable pain and, with the modified program activated, all regions where they experienced LF paresthesia. Paresthesia and pain drawings were then analyzed to estimate the correlation of pain relief outcomes to overlap of pain by paresthesia, and the mediolateral distribution of paresthesia (as a surrogate of physiologic midline lead positioning). A total of 61 patients participated across 11 centers. Twenty-eight men and 33 women with a mean age of 56 ± 12 years of age participated in the study. The average duration of implantable pulse generator (IPG) implant was 19 ± 9 months. The average predominant pain score, as measured on a 0 - 10 visual analog scale (VAS), prior to HF10 therapy was 7.8 ± 1.3 and at time of testing was 2.5 ± 2.1, yielding an average pain relief of 70 ± 24%. For all patients, the mean paresthesia coverage of pain was 21 ± 28%, with 43% of patients having zero paresthesia coverage of pain. Analysis revealed no correlation between percentage of LF paresthesia overlap of predominant pain and HF10 therapy efficacy (P = 0.56). Exact mediolateral positioning of the stimulation electrodes was not found to be a statistically significant predictor of pain relief outcomes. Non-randomized/non-controlled study design; short-term evaluation; certain technical factors not investigated. Both paresthesia concordance with pain and precise midline positioning of the stimulation contacts appear to be inconsequential technical factors for successful HF10 therapy application. These results suggest that HF10 therapy is not only paresthesia-free, but may be paresthesia-independent.

Space Derived Health Aids (PRN, Neuropacemaker)

NASA Technical Reports Server (NTRS)

1981-01-01

St. Jude Medical's (formerly known as Pacesetter Systems, Inc.) Programmable Rechargeable Neuropacemaker (PRN) is an implantable human tissue stimulator designed to provide relief to patients with disorders treatable by electrical stimulation. Examples are back, leg, and arm pain, cancer pain and multiple sclerosis.

Assessment: efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

PubMed

Dubinsky, Richard M; Miyasaki, Janis

2010-01-12

To determine if transcutaneous electric nerve stimulation (TENS) is efficacious in the treatment of pain in neurologic disorders. We performed a systematic literature search of Medline and the Cochrane Library from inception to April 2009. There are conflicting reports of TENS compared to sham TENS in the treatment of chronic low back pain, with 2 Class II studies showing benefit, but 2 Class I studies and another Class II study not showing benefit. Because the Class I studies are stronger evidence, TENS is established as ineffective for the treatment of chronic low back pain (2 Class I studies). TENS is probably effective in treating painful diabetic neuropathy (2 Class II studies). Transcutaneous electric nerve stimulation (TENS) is not recommended for the treatment of chronic low back pain (Level A). TENS should be considered in the treatment of painful diabetic neuropathy (Level B). Further research into the mechanism of action of TENS is needed, as well as more rigorous studies for determination of efficacy.

Effect of Transcutaneous Acupoint Electrical Stimulation on Post-Hemorrhoidectomy-Associated Pain, Anxiety, and Heart Rate Variability: A Randomized-Controlled Study.

PubMed

Yeh, Mei-Ling; Chung, Yu-Chu; Hsu, Lun-Chia; Hung, Shuo-Hui

2018-05-01

Hemorrhoidectomy is the current best treatment for severe hemorrhoids, but it causes significant postoperative pain and anxiety, which is associated with heart rate variability (HRV). Transcutaneous acupoint electrical stimulation (TAES) was assumed to alleviate pain and anxiety, and modify the autonomic nervous system. This study aimed to examine the effects of TAES intervention on postoperative pain, anxiety, and HRV in patients who received a hemorrhoidectomy. A randomized-controlled trial with five repeated measures was conducted. The TAES group ( n = 39) received four 20-min sessions of electrical stimulation at chengshan (BL57) and erbai (EX-UE2) after hemorrhoidectomy, whereas the control group ( n = 41) did not. Data were collected using Visual Analogue Scale (VAS), State Anxiety Inventory (STAI), and HRV physiological signal monitor. TAES resulted in a significant group difference in pain scores, anxiety levels, and some HRV parameters. The findings indicate that TAES can help reduce pain and anxiety associated with hemorrhoidectomy. TAES is a noninvasive, simple, and convenient modality for post-hemorrhoidectomy-associated pain control and anxiety reduction.

Electrotherapy for the treatment of painful diabetic peripheral neuropathy: a review.

PubMed

Pieber, Karin; Herceg, Malvina; Paternostro-Sluga, Tatjana

2010-04-01

To review different types of electrotherapy for the treatment of painful diabetic peripheral neuropathy. A structured search of the electronic database MEDLINE was performed from the time of its initiation to July 2009. Articles in English and German were selected. The efficacy of different types of electrotherapy for painful diabetic peripheral neuropathy has been evaluated in 15 studies; the effects of transcutaneous electrical nerve stimulation are consistent. The beneficial effects of prolonged use have been reported in three large studies and one small study. The effects of frequency-modulated electromagnetic neural stimulation were assessed in one large study, and a significant reduction in pain was reported. Treatment with pulsed and static electromagnetic fields has been investigated in two small and three large studies, and analgesic benefits have been reported. In one large study focusing on pulsed electromagnetic fields, no beneficial effect on pain was registered. Only small studies were found concerning other types of electrotherapy, such as pulsed-dose electrical stimulation, high-frequency external muscle stimulation or high-tone external muscle stimulation. The conclusions drawn in these articles are diverse. Shortcomings and problems, including a poor study design, were observed in some. Further randomized, double-blind, placebo-controlled studies comprising larger sample sizes, a longer duration of treatment, and longer follow-up assessments are required.

The effect of stimulus frequency on the analgesic response to percutaneous electrical nerve stimulation in patients with chronic low back pain.

PubMed

Ghoname, E S; Craig, W F; White, P F; Ahmed, H E; Hamza, M A; Gajraj, N M; Vakharia, A S; Noe, C E

1999-04-01

Low back pain (LBP) is one of the most common medical problems in our society. Increasingly, patients are turning to nonpharmacologic analgesic therapies such as percutaneous electrical nerve stimulation (PENS). We designed this sham-controlled study to compare the effect of three different frequencies of electrical stimulation on the analgesic response to PENS therapy. Sixty-eight consenting patients with LBP secondary to degenerative lumbar disc disease were treated with PENS therapy at 4 Hz, alternating 15 Hz and 30 Hz (15/30 Hz), and 100 Hz, as well as sham-PENS (0 Hz), according to a randomized, cross-over study design. Each treatment was administered for a period of 30 min three times per week for 2 wk. The pre- and posttreatment assessments included the health status survey short form and visual analog scales for pain, physical activity, and quality of sleep. After receiving all four treatments, patients completed a global assessment questionnaire. The sham-PENS treatments failed to produce changes in the degree of pain, physical activity, sleep quality, or daily intake of oral analgesic medications. In contrast, 4-Hz, 15/30-Hz, and 100-Hz stimulation all produced significant decreases in the severity of pain, increases in physical activity, improvements in the quality of sleep, and decreases in oral analgesic requirements (P < 0.01). Of the three frequencies, 15/30 Hz was the most effective in decreasing pain, increasing physical activity, and improving the quality of sleep (P < 0.05). In the global assessment, 40% of the patients reported that 15/30 Hz was the most desirable therapy, and it was also more effective in improving the patient's sense of well-being. We conclude that the frequency of electrical stimulation is an important determinant of the analgesic response to PENS therapy. Alternating stimulation at 15-Hz and 30-Hz frequencies was more effective than either 4 Hz or 100 Hz in improving outcome measures in patients with LBP. The frequency of electrical stimulation seems to be an important determinant of the analgesic efficacy of percutaneous electrical nerve stimulation. Mixed low- and high-frequency stimulation was more effective than either low or high frequencies alone in the treatment of patients with low back pain.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

PubMed Central

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre

2014-01-01

Objective: To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. Data Sources: PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Review Methods: Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. Results: A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. Conclusion: This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality. PMID:26770730

Could autonomic system assessment be helpful in disorders of consciousness diagnosis? A neurophysiological study.

PubMed

Leo, Antonino; Naro, Antonino; Cannavò, Antonio; Pisani, Laura Rosa; Bruno, Rocco; Salviera, Carlo; Bramanti, Placido; Calabrò, Rocco Salvatore

2016-08-01

Although patients with chronic disorders of consciousness (DOC), including unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), show a limited repertoire of awareness signs, owing to a large-scale cortico-thalamo-cortical functional disconnectivity, an activation of some cortical areas in response to relevant stimuli has been described by means of electrophysiological and functional neuroimaging approaches. In addition, cognitive processes associated with autonomic nervous system (ANS) responses elicited by nociceptive stimuli have been identified in some DOC patients. In an attempt to identify ANS functionality markers that could be useful in differentiating UWS and MCS individuals, we measured the amplitude, latency and γ-band power (γPOW) of ultra-late laser-evoked potentials (CLEPs) and skin reflex (SR), which both express some aspects of cognitive processes related to ANS functionality, besides other ANS parameters either during a 24(hh)-polygraphy or following a solid-state laser repetitive nociceptive stimulation. MCS showed physiological modification of vital signs (O2 saturation, hearth rate, hearth rate variability) throughout the night and a preservation of SR-γPOW, whereas UWS did not show significant variations. Following repetitive nociceptive stimulation, MCS patients had a significant increase in CLEP-γPOW, O2 saturation, hearth rate, and hearth rate variability, whereas UWS individuals did not show any significant change (but two patients, who reached high Coma Recovery Scale-Revised scores). Hence, our work suggests that a wide-spectrum electrophysiological evaluation of ANS functionality may support DOC differential diagnosis. Interestingly, the two above-mentioned UWS patients showed MCS-like vital sign modifications and electrophysiological pain responsiveness. It is therefore hypothesizable that our approach could be helpful in identifying residual aware autonomic system-related cognitive processes even in some UWS patients. Such issue draws the attention to either DOC clinical diagnosis or adequate pain treatment in DOC patients.

Low Level Laser Therapy for chronic knee joint pain patients.

PubMed

Nakamura, Takashi; Ebihara, Satoru; Ohkuni, Ikuko; Izukura, Hideaki; Harada, Takashi; Ushigome, Nobuyuki; Ohshiro, Toshio; Musha, Yoshiro; Takahashi, Hiroshi; Tsuchiya, Kazuaki; Kubota, Ayako

2014-12-27

Chronic knee joint pain is one of the most frequent complaints which is seen in the outpatient clinic in our medical institute. In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic pain in the shoulder joints, elbow, hand, finger and the lower back. The present study is a report on the effects of LLLT for chronic knee joint pain. Over the past 5 years, 35 subjects visited the outpatient clinic with complaints of chronic knee joint pain caused by the knee osteoarthritis-induced degenerative meniscal tear. They received low level laser therapy. A 1000 mW semi-conductor laser device was used to deliver 20.1 J/cm(2) per point in continuous wave at 830nm, and four points were irradiated per session (1 treatment) twice a week for 4 weeks. A visual analogue scale (VAS) was used to determine the effects of LLLT for the chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). After treatment, no significant differences were observed in the knee joint range of motion. Discussions with the patients revealed that it was important for them to learn how to avoid postures that would cause them knee pain in everyday life in order to have continuous benefits from the treatment. The present study demonstrated that 830 nm LLLT was an effective form of treatment for chronic knee pain caused by knee osteoarthritis. Patients were advised to undertake training involving gentle flexion and extension of the knee.

Protein conformational modulation by photons: a mechanism for laser treatment effects.

PubMed

Liebert, Ann D; Bicknell, Brian T; Adams, Roger D

2014-03-01

Responsiveness to low-level laser treatment (LLTT) at a wavelength of 450-910 nm has established it as an effective treatment of medical, veterinary and dental chronic pain, chronic inflammation conditions (arthritis and macular degeneration), wound repair, and lymphoedema, yet the mechanisms underlying the effectiveness of LLLT remain unclear. However, there is now sufficient evidence from recent research to propose an integrated model of LLLT action. The hypothesis presented in this paper is that external applications of photons (through laser at an appropriate dose) modulates the nervous system through an integrated mechanism. This stimulated mechanism involves protein-to-protein interaction, where two or more proteins bind together to facilitate molecular processes, including modification of proteins by members of SUMO (small ubiquitin-related modifier proteins) and also protein phosphorylation and tyrosination. SUMO has been shown to have a role in multiple nuclear and perinuclear targets, including ion channels, and in the maintenance of telomeres and the post-translational modification of genes. The consequence of laser application in treatment, therefore, can be seen as influencing the transmission of neural information via an integrated and rapid modulation of ion channels, achieved through both direct action on photo-acceptors (such as cytochrome c-oxidase) and through indirect modulation via enzymes, including tyrosine hydroxylase (TH), tyrosine kinases and tyrosine kinase receptors. This exogenous action then facilitates an existing photonic biomodulation mechanism within the body, and initiates ion channel modulation both in the periphery and the central nervous system (CNS). Evidence indicates that the ion channel modulation functions predominately through the potassium channels, including two pore leak channels (K2P), which act as signal integrators from the periphery to the cortex. Photonic action also transforms SUMOylation processes at the cell membrane, nucleus and telomeres via signalling processes from the mitochondria (which is the main target of laser absorption) to these targets. Under the hypothesis, these observed biological effects would play a part in the bystander effect, the abscopal effect, and other systemic effects observed with the application of low level laser (LLLT). The implications of the hypothesis are important in that they point to mechanisms that can account for the effectiveness of laser in the treatment and prevention of inflammatory diseases, chronic pain and neurodegenerative disorders. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Immunological responses induced by the combination of phototherapy and immunotherapy in the treatment of metastatic tumors

NASA Astrophysics Data System (ADS)

Chen, Wei R.; Naylor, Mark F.; Nordquist, Robert E.; Teague, T. Kent; Liu, Hong

2008-02-01

Combination therapy using laser photothermal interaction and immunological stimulation has demonstrated its ability to induce immunological responses. Glycated chitosan (GC), an immunological stimulant, and imiquimod, a new type of immune response modifier (IRM), when used in conjunction with laser phototherapy, have shown to have a great immunological stimulation function. Specifically, imiquimod can help release cytokines from immunocompetent cells, stimulate TH1 lymphocyte responses (CD8+ T-cells), and recruit additional dendritic cells. To study the effects of immunoadjuvnats in combination of laser photo-irradiation, we treated animal tumors with laser-ICG-GC combination and late-stage melanoma patients with laser-ICG-imiquimod combination. At designated times, tumors, blood, and spleens in both treated and untreated animals were colleted for analysis. The major immunological indicators, such as IL-6, IL-12, IFN-gamma, CD4, and CD8 were analyzed. The same immunological analysis was also performed for melanoma patients treated by the laser-imiquimod combination.

Laser-induced thermoelastic effects can evoke tactile sensations

NASA Astrophysics Data System (ADS)

Jun, Jae-Hoon; Park, Jong-Rak; Kim, Sung-Phil; Min Bae, Young; Park, Jang-Yeon; Kim, Hyung-Sik; Choi, Seungmoon; Jung, Sung Jun; Hwa Park, Seung; Yeom, Dong-Il; Jung, Gu-In; Kim, Ji-Sun; Chung, Soon-Cheol

2015-06-01

Humans process a plethora of sensory information that is provided by various entities in the surrounding environment. Among the five major senses, technology for touch, haptics, is relatively young and has relatively limited applications largely due to its need for physical contact. In this article, we suggest a new way for non-contact haptic stimulation that uses laser, which has potential advantages such as mid-air stimulation, high spatial precision, and long working distance. We demonstrate such tactile stimulation can be enabled by laser-induced thermoelastic effects by means of physical and perceptual studies, as well as simulations. In the physical study, the mechanical effect of laser on a human skin sample is detected using low-power radiation in accordance with safety guidelines. Limited increases (< ~2.5 °C) in temperature at the surface of the skin, examined by both thermal camera and the Monte Carlo simulation, indicate that laser does not evoke heat-induced nociceptive sensation. In the human EEG study, brain responses to both mechanical and laser stimulation are consistent, along with subjective reports of the non-nociceptive sensation of laser stimuli.

Laser-induced thermoelastic effects can evoke tactile sensations.

PubMed

Jun, Jae-Hoon; Park, Jong-Rak; Kim, Sung-Phil; Min Bae, Young; Park, Jang-Yeon; Kim, Hyung-Sik; Choi, Seungmoon; Jung, Sung Jun; Hwa Park, Seung; Yeom, Dong-Il; Jung, Gu-In; Kim, Ji-Sun; Chung, Soon-Cheol

2015-06-05

Humans process a plethora of sensory information that is provided by various entities in the surrounding environment. Among the five major senses, technology for touch, haptics, is relatively young and has relatively limited applications largely due to its need for physical contact. In this article, we suggest a new way for non-contact haptic stimulation that uses laser, which has potential advantages such as mid-air stimulation, high spatial precision, and long working distance. We demonstrate such tactile stimulation can be enabled by laser-induced thermoelastic effects by means of physical and perceptual studies, as well as simulations. In the physical study, the mechanical effect of laser on a human skin sample is detected using low-power radiation in accordance with safety guidelines. Limited increases (< ~2.5 °C) in temperature at the surface of the skin, examined by both thermal camera and the Monte Carlo simulation, indicate that laser does not evoke heat-induced nociceptive sensation. In the human EEG study, brain responses to both mechanical and laser stimulation are consistent, along with subjective reports of the non-nociceptive sensation of laser stimuli.

Heightened brain response to pain anticipation in high-functioning adults with autism spectrum disorder.

PubMed

Gu, Xiaosi; Zhou, Thomas J; Anagnostou, Evdokia; Soorya, Latha; Kolevzon, Alexander; Hof, Patrick R; Fan, Jin

2018-03-01

Autism spectrum disorder (ASD) is marked by both socio-communicative difficulties and abnormalities in sensory processing. Much of the work on sensory deficits in ASD has focused on tactile sensations and the perceptual aspects of somatosensation, such as encoding of stimulus intensity and location. Although aberrant pain processing has often been noted in clinical observations of patients with ASD, it remains largely uninvestigated. Importantly, the neural mechanism underlying higher order cognitive aspects of pain processing such as pain anticipation also remains unknown. Here we examined both pain perception and anticipation in high-functioning adults with ASD and matched healthy controls (HC) using an anticipatory pain paradigm in combination with functional magnetic resonance imaging (fMRI) and concurrent skin conductance response (SCR) recording. Participants were asked to choose a level of electrical stimulation that would feel moderately painful to them. Compared to HC group, ASD group chose a lower level of stimulation prior to fMRI. However, ASD participants showed greater activation in both rostral and dorsal anterior cingulate cortex during the anticipation of stimulation, but not during stimulation delivery. There was no significant group difference in insular activation during either pain anticipation or perception. However, activity in the left anterior insula correlated with SCR during pain anticipation. Taken together, these results suggest that ASD is marked with aberrantly higher level of sensitivity to upcoming aversive stimuli, which may reflect abnormal attentional orientation to nociceptive signals and a failure in interoceptive inference. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Standardizing therapeutic parameters of acupuncture for pain suppression in rats: preliminary study.

PubMed

Yeo, Sujung; Lim, Hyungtaeck; Choe, Ilwhan; Kim, Sung-Hoon; Lim, Sabina

2014-01-15

Despite acupuncture's wide and successful use, it is still considered as lacking scientifically rigorous evidence, especially with respect to its effectiveness. To address this problem, it is necessary to re-examine the practice of acupuncture using scientific methodology. The standardization of acupuncture practices may offer a solution. As a preliminary step towards the standardization of acupuncture stimulation in animal experiments, this study attempted to clarify the various therapeutic parameters that contribute to acupuncture's efficacy. This study identified specific acupoints, temporal point of needling, rotation of the needle, duration of acupuncture, and diameter of the needle as the parameters, through formalin test. In this test, acupuncture was performed on either the ST36 or LR2 point immediately after pain induction and 5 minutes after pain induction. The formalin test yielded no significant suppression of pain in the case of ST36 and LR2 acupuncture stimulation immediately following pain induction. When acupuncture was applied 5 minutes after pain induction, however, the ST36 stimulation resulted in a significant decrease in pain, while the LR2 stimulation produced no change. The duration of acupuncture, but not the diameter of the needle, was also significant. As for the rotation of the needle, there was no significant difference in the pain reduction achieved in the rotation and non-rotation groups. We determined that specific acupoint, temporal point of needling, and duration of treatment are important factors in the inhibition of pain. These finding strongly suggest that in animal experiments, the application of a set of appropriate therapeutic parameters can significantly influence the outcome.

Investigating the neural processing of spatial summation of pain: the role of A-delta nociceptors.

PubMed

Raz, Netta; Granovsky, Yelena; Defrin, Ruth

2015-02-01

The underlying mechanism of spatial summation (SS) of pain, an essential component in pain perception and detection, is unknown. Because of the possible differential innervations by A-delta nociceptors and pain sensitivity of hairy and glabrous skin, a comparison of the SS characteristics between the two skin types could contribute to the elucidation of its subserving system and processing. The effect of sex on SS of pain was also evaluated due to the scarcity of information on the subject. Twenty-nine healthy subjects (13 males, 16 females) received four series of heat stimuli of various intensities, in hairy and glabrous skin of the hand using large (27 mm diameter) and small (12 mm) stimulation areas, and the perceived pain intensity (PPI) was rated. A fast temperature increase rate (70°/s) was used in order to selectively activate A-delta nociceptors. The effect of skin type, stimulation intensity and sex on SS and PPI was calculated. Skin type significantly affected PPI and SS of pain; values of both variables were significantly greater in hairy compared with glabrous skin. SS of pain gradually increased concomitantly with stimulation intensity magnitude, to a point when it became saturated in both skin types. Females exhibited greater SS in glabrous skin. It would appear that AMH-II nociceptive fibers in particular subserve SS of pain. Furthermore, SS is increased under stronger stimulation intensities, probably as defense mechanism against tissue damage. Sex differences in dynamic sensory processes such as SS are revealed only under conditions where the phenomenon is subtle (as in glabrous skin).

Test-retest reliability of evoked heat stimulation BOLD fMRI.

PubMed

Upadhyay, Jaymin; Lemme, Jordan; Anderson, Julie; Bleakman, David; Large, Thomas; Evelhoch, Jeffrey L; Hargreaves, Richard; Borsook, David; Becerra, Lino

2015-09-30

To date, the blood oxygenated-level dependent (BOLD) functional magnetic resonance imaging (fMRI) technique has enabled an objective and deeper understanding of pain processing mechanisms embedded within the human central nervous system (CNS). In order to further comprehend the benefits and limitations of BOLD fMRI in the context of pain as well as the corresponding subjective pain ratings, we evaluated the univariate response, test-retest reliability and confidence intervals (CIs) at the 95% level of both data types collected during evoked stimulation of 40°C (non-noxious), 44°C (mildly noxious) and a subject-specific temperature eliciting a 7/10 pain rating. The test-retest reliability between two scanning sessions was determined by calculating group-level interclass correlation coefficients (ICCs) and at the single-subject level. Across the three stimuli, we initially observed a graded response of increasing magnitude for both VAS (visual analog score) pain ratings and fMRI data. Test-retest reliability was observed to be highest for VAS pain ratings obtained during the 7/10 pain stimulation (ICC=0.938), while ICC values of pain fMRI data for a distribution of CNS structures ranged from 0.5 to 0.859 (p<0.05). Importantly, the upper and lower confidence interval CI bounds reported herein could be utilized in subsequent trials involving healthy volunteers to hypothesize the magnitude of effect required to overcome inherent variability of either VAS pain ratings or BOLD responses evoked during innocuous or noxious thermal stimulation. Copyright © 2015 Elsevier B.V. All rights reserved.

Electroconvulsive stimulation (ECS) increases the expression of neuropeptide Y (NPY) in rat brains in a model of neuropathic pain: a quantitative real-time polymerase chain reaction (RT-PCR) study.

PubMed

Okabe, Tadashi; Sato, Chiyo; Matsumoto, Keisuke; Ozawa, Hitoshi; Sakamoto, Atsuhiro

2009-11-01

Electroconvulsive shock therapy (ECT) has been widely used as an effective and established treatment for refractory depression and schizophrenia. Some reports have shown that ECT is also effective for treating refractory neuropathic pain. In a rat model of neuropathic pain produced by chronic constrictive injury (CCI) of the sciatic nerve, thermal hyperalgesia, and mechanical allodynia were observed from day 2 after surgery. An electroconvulsive shock (ECS) was administered to rodents once daily for 6 days on days 7-12 after CCI operation using a pulse generator. Thermal and mechanical stimulation tests were performed to assess pain thresholds. Real-time polymerase chain reaction was used to measure the gene expression levels for 5HT(1A)R, 5HT(2A)R, neuropeptide Y (NPY), and GABAA(alpha1)R in the brain. After ECS, the latency to withdrawal from thermal stimulation was significantly increased; however, pain withdrawal thresholds in response to mechanical stimulation were not significantly changed. Expression ratios of NPY were significantly greater after ECS. Symptoms of neuropathic pain improved and expression of NPY in the brain was increased in CCI model rats after ECS, suggesting that changes in the expression of NPY in the brain may be related to the mechanism of action of ECT in treating neuropathic pain.

Optimizing Stimulation in a Case of Facial Pain Through "Cross-Talk" of Peripheral and Central Leads: A Case Report.

PubMed

McRoberts, W Porter

2016-12-01

To describe inter-lead (cross-talk) stimulation between a trigeminal nerve lead and a cervical epidural lead for the treatment of facial pain in a 69-year-old patient with empty nose syndrome. A trial implant was performed with a peripheral V2 trigeminal lead and a C1-C2 lead in cross-talk configuration. During permanent implant, the V2 lead was placed uneventfully while the central lead could only be advanced to C3-C4. During the trial, pain decreased by 70%. One month after permanent implant, the patient still experienced a 60-70% reduction in pain levels and a decrease from ten to two weekly pain episodes. Nine months post implant, the patient reported complete pain relief (0/10 on a numeric rating scale ranging from 0 to 10) and medications were discontinued. Infrequent exacerbations (3/10) were controlled by increasing stimulation. Three years post implant, the patient continued to have no baseline pain and could easily control exacerbations. Cross-talk configuration between a peripheral and a central lead created a more efficient stimulation technique. The resulting paresthesia was superior to that obtained from either lead alone and exceeded the paresthesia obtained from the combination of the two leads when used simultaneously, without an inter-lead configuration. © 2016 International Neuromodulation Society.

The differential effect of trigeminal vs. peripheral pain stimulation on visual processing and memory encoding is influenced by pain-related fear.

PubMed

Schmidt, K; Forkmann, K; Sinke, C; Gratz, M; Bitz, A; Bingel, U

2016-07-01

Compared to peripheral pain, trigeminal pain elicits higher levels of fear, which is assumed to enhance the interruptive effects of pain on concomitant cognitive processes. In this fMRI study we examined the behavioral and neural effects of trigeminal (forehead) and peripheral (hand) pain on visual processing and memory encoding. Cerebral activity was measured in 23 healthy subjects performing a visual categorization task that was immediately followed by a surprise recognition task. During the categorization task subjects received concomitant noxious electrical stimulation on the forehead or hand. Our data show that fear ratings were significantly higher for trigeminal pain. Categorization and recognition performance did not differ between pictures that were presented with trigeminal and peripheral pain. However, object categorization in the presence of trigeminal pain was associated with stronger activity in task-relevant visual areas (lateral occipital complex, LOC), memory encoding areas (hippocampus and parahippocampus) and areas implicated in emotional processing (amygdala) compared to peripheral pain. Further, individual differences in neural activation between the trigeminal and the peripheral condition were positively related to differences in fear ratings between both conditions. Functional connectivity between amygdala and LOC was increased during trigeminal compared to peripheral painful stimulation. Fear-driven compensatory resource activation seems to be enhanced for trigeminal stimuli, presumably due to their exceptional biological relevance. Copyright © 2016 Elsevier Inc. All rights reserved.

Autonomic responses to tonic pain are more closely related to stimulus intensity than to pain intensity.

PubMed

Nickel, Moritz M; May, Elisabeth S; Tiemann, Laura; Postorino, Martina; Ta Dinh, Son; Ploner, Markus

2017-11-01

Pain serves the protection of the body by translating noxious stimulus information into a subjective percept and protective responses. Such protective responses rely on autonomic responses that allocate energy resources to protective functions. However, the precise relationship between objective stimulus intensity, subjective pain intensity, autonomic responses, and brain activity is not fully clear yet. Here, we addressed this question by continuously recording pain ratings, skin conductance, heart rate, and electroencephalography during tonic noxious heat stimulation of the hand in 39 healthy human subjects. The results confirmed that pain intensity dissociates from stimulus intensity during 10 minutes of noxious stimulation. Furthermore, skin conductance measures were significantly related to stimulus intensity but not to pain intensity. Correspondingly, skin conductance measures were significantly related to alpha and beta oscillations in contralateral sensorimotor cortex, which have been shown to encode stimulus intensity rather than pain intensity. No significant relationships were found between heart rate and stimulus intensity or pain intensity. The findings were consistent for stimulation of the left and the right hands. These results suggest that sympathetic autonomic responses to noxious stimuli in part directly result from nociceptive rather than from perceptual processes. Beyond, these observations support concepts of pain and emotions in which sensory, motor, and autonomic components are partially independent processes that together shape emotional and painful experiences.

Electrical stimulation (ES) in the management of sexual pain disorders.

PubMed

Nappi, Rossella E; Ferdeghini, Francesea; Abbiati, Ileana; Vercesi, Claudia; Farina, Claudio; Polatti, Franco

2003-01-01

We performed an open study to investigate the use of electrical stimulation (ES) on the vestibular area and vaginal introitus in women with sexual pain disorders. We recruited 29 women (age range 20-45 years) from among the patients at our Reproductive Psychobiology Unit to participate in the present study. They each experienced vestibular pain, inducing dyspareunia and vaginism. We performed ES with an ECL43400 apparatus (Elite, EssediEsse srl, Milan, Italy) once a week for 10 weeks. To evaluate the muscular activity of the perineal floor and sexual function, we employed the same apparatus with a vaginal probe for recording myoelectrical activity (muV), we employed a VAS scale for evaluating pain, and we administered the Female Sexual Function Index (FSFI; Rosen et al., 2000) before and after the study protocol. We analyzed data by parametric and nonparametric comparisons and correlations, as appropriate. Our major findings were as follows: (a) the contractile ability of pelvic floor muscles (p < 0.001), as well as the resting ability (p < 0.001), significantly improved following ES; (b) the current intensity tolerated significantly increased (p < 0.001) throughout the study, from 41.3 +/- 7.4 mA at the start of the study to 50 +/- 7.4 mA at the end of the stimulation protocol; (c) the Visual Analogic Scale (VAS) for pain significantly declined (p < 0.001), whereas FSFI pain scores (p < 0.001) and full scale scores (p < 0.001) significantly improved following ES, and 4 out of 9 women with vaginism went back to coital activity; (d) FSFI pain score and the current intensity tolerated, both before (R = .59; p < 0.006) and at the end (R = .53; p < 0.02) of the stimulation protocol, positively correlated. ES may be effective in the management of sexual pain disorders. Further controlled studies are necessary to standardize stimulation protocols according to the severity of pain and to better clarify the long-term clinical effects of ES.

Stimulated emission from ladder-type two-photon coherent atomic ensemble.

PubMed

Park, Jiho; Moon, Han Seb

2018-05-28

We investigated the stimulated emission from a ladder-type two-photon coherent atomic ensemble, for the 5S 1/2 - 5P 3/2 - 5D 5/2 transition of 87 Rb atoms. Under the ladder-type two-photon resonance condition obtained using pump and coupling lasers, we observed broad four-wave mixing (FWM) light stimulated from two-photon coherence induced by the seed laser coupled between the ground state of 5S 1/2 and the first excited state of 5P 3/2 . A dip in the FWM spectrum was obtained for three-photon resonance due to V-type two-photon coherence using the pump and seed lasers. From the FWM spectra obtained for varying frequency detuning and seed-laser power, we determined that the seed laser acts as a stimulator for FWM generation, but also acts as a disturber of FWM due to V-type two-photon coherence.

The use of a stimulating catheter for total knee replacement surgery - preliminary results

PubMed Central

Jack, Nigel T.M.; Liem, Edwin B.; Vonhögen, Leon H.

2006-01-01

Summary Background There is continuing debate as to whether the use of electrical stimulation that aids in localizing nerves is also beneficial for optimizing placement of nerve catheters and will lead to improved clinical outcomes such as reductions in pain scores and opioid consumption. Methods We undertook a retrospective, non-randomized comparison of stimulating and non-stimulating nerve catheters in 419 patients undergoing total knee replacement between December 2002 and July 2004. Pre-operatively, patients received sciatic and femoral nerve blocks, with a catheter for the femoral nerve. In 159 patients, a stimulating (Stimucath, Arrow International, Reading, PA) and, in 260 patients, a non-stimulating (Contiplex, BBraun, Melsungen, Germany) catheter system was used. Postoperatively, pain scores and morphine consumption were recorded at 4-hour intervals until the first postoperative morning. In a subset of 85 patients, the postoperative evaluation period was lengthened to three days. Results Post-operative visual analogue scores (VAS) for pain were similar in the two groups during the first 24 hours (P = 0.305). In patients followed for three days, VAS scores did not differ on any of the days (P = 0.427). Total morphine consumption did not differ on the first post-operative day (Stimulating: 12.4 [10.1-14.7] vs. non-stimulating: 10.4 [8.9-11.8]; mean [95% CI]; P=0.140) or on subsequent days. Conclusions The practical advantages of the stimulating catheter, as by reported by previous investigators, were not obvious in this clinical situation. In terms of outcome measures such as pain scores and morphine consumption, we found no significant differences between stimulating and non-stimulating catheters. PMID:15923268

Implementation of a portable electronic system for providing pain relief to patellofemoral pain syndrome patients

NASA Astrophysics Data System (ADS)

Chang Chien, Jia-Ren; Lin, Guo-Hong; Hsu, Ar-Tyan

2011-10-01

In this study, a portable electromyogram (EMG) system and a stimulator are developed for patellofemoral pain syndrome patients, with the objective of reducing the pain experienced by these patients; the patellar pain is caused by an imbalance between the vastus medialis obliquus (VMO) and the vastus lateralis (VL). The EMG measurement circuit and the electrical stimulation device proposed in this study are specifically designed for the VMO and the VL; they are capable of real-time waveform recording, possess analyzing functions, and can upload their measurement data to a computer for storage and analysis. The system can calculate and record the time difference between the EMGs of the VMO and the VL, as well as the signal strengths of both the EMGs. As soon as the system detects the generation of the EMG of the VL, it quickly calculates and processes the event and stimulates the VMO as feedback through electrical stimulation units, in order to induce its contraction. The system can adjust the signal strength, time length, and the sequence of the electrical stimulation, both manually and automatically. The output waveform of the electrical stimulation circuit is a dual-phase asymmetrical pulse waveform. The primary function of the electrical simulation circuit is to ensure that the muscles contract effectively. The performance of the device can be seen that the width of each pulse is 20-1000 μs, the frequency of each pulse is 10-100 Hz, and current strength is 10-60 mA.

A compact, inexpensive infrared laser system for continuous-wave optical stimulation of the rat prostate cavernous nerves

NASA Astrophysics Data System (ADS)

Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2014-03-01

Optical nerve stimulation (ONS) has been commonly performed in the laboratory using high-power, pulsed, infrared (IR) lasers including Holmium:YAG, diode, and Thulium fiber lasers. However, the relatively high cost of these lasers in comparison with conventional electrical nerve stimulation (ENS) equipment may represent a significant barrier to widespread adoption of ONS. Optical stimulation of the prostate cavernous nerves (CN's) has recently been reported using lower cost, continuous-wave (CW), all-fiber-based diode lasers. This preliminary study describes further miniaturization and cost reduction of the ONS system in the form of a compact, lightweight, cordless, and inexpensive IR laser. A 140-mW, 1560-nm diode laser was integrated with a green aiming beam and delivery optics into a compact ONS system. Surface and subsurface ONS was performed in a total of 5 rats, in vivo, with measurement of an intracavernous pressure (ICP) response during CW laser irradiation for 30 s with a spot diameter of 0.7 mm. Short-term, CW ONS of the prostate CN's is feasible using a compact, inexpensive, batterypowered IR laser diode system. This ONS system may represent an alternative to ENS for laboratory studies, and with further development, a handheld option for ONS in the clinic to identify and preserve the CN's during prostate cancer surgery.

Different Brain Responses to Pain and Its Expectation in the Dental Chair.

PubMed

Racek, A J; Hu, X; Nascimento, T D; Bender, M C; Khatib, L; Chiego, D; Holland, G R; Bauer, P; McDonald, N; Ellwood, R P; DaSilva, A F

2015-07-01

A dental appointment commonly prompts fear of a painful experience, yet we have never fully understood how our brains react to the expectation of imminent tooth pain once in a dental chair. In our study, 21 patients with hypersensitive teeth were tested using nonpainful and painful stimuli in a clinical setting. Subjects were tested in a dental chair using functional near-infrared spectroscopy to measure cortical activity during a stepwise cold stimulation of a hypersensitive tooth, as well as nonpainful control stimulation on the same tooth. Patients' sensory-discriminative and emotional-cognitive cortical regions were studied through the transition of a neutral to a painful stimulation. In the putative somatosensory cortex contralateral to the stimulus, 2 well-defined hemodynamic peaks were detected in the homuncular orofacial region: the first peak during the nonpainful phase and a second peak after the pain threshold was reached. Moreover, in the upper-left and lower-right prefrontal cortices, there was a significant active hemodynamic response in only the first phase, before the pain. Subsequently, the same prefrontal cortical areas deactivated after a painful experience had been reached. Our study indicates for the first time that pain perception and expectation elicit different hemodynamic cortical responses in a dental clinical setting. © International & American Associations for Dental Research 2015.

The advantages of carbon dioxide laser applications in paediatric oral surgery. A prospective cohort study.

PubMed

Hanna, R; Parker, S

2016-11-01

The aim of this study is to evaluate and demonstrate the advantages of the carbon dioxide laser in paediatric oral surgery patients in terms of less post-operative complications, healing without scaring, functional benefits, positive patient perception and acceptance of the treatment. One hundred fit and healthy paediatric patients (aged 4-15 years) were recruited to undergo laser surgery for different soft tissue conditions. The outcome of these laser treatments was examined. The Wong-Baker Faces Pain Rating Scale was employed to evaluate the pain before, immediately after laser treatment in the clinic and 1 day after post-operatively at home. Post-operative complications and patients' perception and satisfaction were self-reported during a review telephone call the day after treatment. The patients were reviewed 2 weeks after surgery. Laser parameter was 1.62 W, measured by power meter, continuous wave mode with 50 % emission cycle. The beam spot size at the target tissue was 0.8 mm. The pain score pre-operative, during and immediately after laser treatment was rated 0. Whilst the pain score 1 day after surgery was rated between 0 and 2, the healing time was measured over 2 weeks. None of the patients reported post-operative complications after surgery. Patients' perception and acceptance were rated very good. Laser dentistry is a promising field in modern minimally invasive dentistry, which enables provision of better care for children and adolescents. In this cohort study, the use of the carbon dioxide laser therapy offers a desirable, acceptable and minimally invasive technique in the surgical management of soft tissues in paediatric oral surgery with minimal post-operative complications.

Was it less painful for knights? Influence of appearance on pain perception.

PubMed

Weeth, A; Mühlberger, A; Shiban, Y

2017-11-01

Pain perception is a subjective experience shaped by different factors. In this study, we investigated the influence of a visually manipulated appearance of a virtual arm on pain perception. Specifically, we investigated how pain perception and vegetative skin responses were modified by inducing a virtual protection on the right arm by a virtual armour. Participants (n = 32) immersed in virtual reality embodied a virtual arm, which appeared in three different versions (uncovered, neutral or protected). During the virtual reality simulation, the participants received electrical stimulations of varying intensities. Skin conductance level (SCL) was analysed for the phase anticipation (from the moment the arm appeared until the electric stimulation) and perception of pain (after the electric stimulation). Pain ratings were acquired after the painful stimuli occurred. The sense of embodiment was positive for the unprotected and neutral condition and lower for the protected than for the neutral arm. Pain ratings were significantly decreased in the protected arm condition compared with both the unprotected arm and the neutral arm conditions. The SCL measurements showed no significant differences for the three arm types. According to the pain ratings, participants felt significantly less pain in the covered arm condition compared with the unprotected and the neutral arm condition. Subjective pain perception was decreased by a virtual protection of the arm in VR. The simplicity of the manipulation suggests possible practical uses in pain therapy by strengthening the patients' own capacities to influence their pain using simple cognitive manipulations via virtual reality. A virtual, covered arm causes differences in reported pain ratings. Physiological measurements do not confirm the findings. Visual information about body protection can have an impact on pain perception. © 2017 European Pain Federation - EFIC®.

Characterization of sputtered iridium oxide thin films on planar and laser micro-structured platinum thin film surfaces for neural stimulation applications

NASA Astrophysics Data System (ADS)

Thanawala, Sachin

Electrical stimulation of neurons provides promising results for treatment of a number of diseases and for restoration of lost function. Clinical examples include retinal stimulation for treatment of blindness and cochlear implants for deafness and deep brain stimulation for treatment of Parkinsons disease. A wide variety of materials have been tested for fabrication of electrodes for neural stimulation applications, some of which are platinum and its alloys, titanium nitride, and iridium oxide. In this study iridium oxide thin films were sputtered onto laser micro-structured platinum thin films by pulsed-DC reactive sputtering of iridium metal in oxygen-containing atmosphere, to obtain high charge capacity coatings for neural stimulation applications. The micro-structuring of platinum films was achieved by a pulsed-laser-based technique (KrF excimer laser emitting at lambda=248nm). The surface morphology of the micro-structured films was studied using different surface characterization techniques. In-vitro biocompatibility of these laser micro-structured films coated with iridium oxide thin films was evaluated using cortical neurons isolated from rat embryo brain. Characterization of these laser micro-structured films coated with iridium oxide, by cyclic voltammetry and impedance spectroscopy has revealed a considerable decrease in impedance and increase in charge capacity. A comparison between amorphous and crystalline iridium oxide thin films as electrode materials indicated that amorphous iridium oxide has significantly higher charge capacity and lower impedance making it preferable material for neural stimulation application. Our biocompatibility studies show that neural cells can grow and differentiate successfully on our laser micro-structured films coated with iridium oxide. This indicates that reactively sputtered iridium oxide (SIROF) is biocompatible.

Low Level Laser Therapy for Patients with Cervical Disk Hernia

PubMed Central

Takahashi, Hiroshi; Okuni, Ikuko; Ushigome, Nobuyuki; Harada, Takashi; Tsuruoka, Hiroshi; Ohshiro, Toshio; Sekiguchi, Masayuki; Musya, Yoshiro

2012-01-01

Background and Aims: In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic shoulder joint pain, elbow, hand and finger pain, and low back pain. The present study is a report on the effects of LLLT for chronic neck pain. Materials and Methods: Over a 3 year period, 26 rehabilitation department outpatients with chronic neck pain, diagnosed as being caused by cervical disk hernia, underwent treatment applied to the painful area with a 1000 mW semi-conductor laser device delivering at 830 nm in continuous wave, 20.1 J/cm2/point, and three shots were given per session (1 treatment) with twice a week for 4 weeks. Results: 1. A visual analogue scale (VAS) was used to determine the effects of LLLT for chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). 2. After treatment, no significant differences in cervical spine range of motion were observed. 3. Discussions with the patients revealed that in order to receive continued benefits from treatment, it was important for them to be taught how to avoid postures that would cause them neck pain in everyday life. Conclusion: The present study demonstrates that LLLT was an effective form of treatment for neck and back pain caused by cervical disk hernia, reinforced by postural training. PMID:24511189

Deep brain stimulation of the subthalamic nucleus improves pain in Parkinson's disease.

PubMed

Pellaprat, Jean; Ory-Magne, Fabienne; Canivet, Cindy; Simonetta-Moreau, Marion; Lotterie, Jean-Albert; Radji, Fatai; Arbus, Christophe; Gerdelat, Angélique; Chaynes, Patrick; Brefel-Courbon, Christine

2014-06-01

In Parkinson's disease (PD), chronic pain is a common symptom which markedly affects the quality of life. Some physiological arguments proposed that Deep Brain Stimulation of the Subthalamic Nucleus (STN-DBS) could improve pain in PD. We investigated in 58 PD patients the effect of STN-DBS on pain using the short McGill Pain Questionnaire and other pain parameters such as the Bodily discomfort subscore of the Parkinson's disease Questionnaire 39 and the Unified Parkinson's Disease Rating Scale section II (UPDRS II) item 17. All pain scores were significantly improved 12 months after STN-DBS. This improvement was not correlated with motor improvement, depression scores or L-Dopa reduction. STN-DBS induced a substantial beneficial effect on pain in PD, independently of its motor effects and mood status of patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spinal cord stimulation: Current applications for treatment of chronic pain.

PubMed

Vannemreddy, Prasad; Slavin, Konstantin V

2011-01-01

Spinal cord stimulation (SCS) is thought to relieve chronic intractable pain by stimulating nerve fibers in the spinal cord. The resulting impulses in the fibers may inhibit the conduction of pain signals to the brain, according to the pain gate theory proposed by Melzack and Wall in 1965 and the sensation of pain is thus blocked. Although SCS may reduce pain, it will not eliminate it. After a period of concern about safety and efficacy, SCS is now regaining popularity among pain specialists for the treatment of chronic pain. The sympatholytic effect of SCS is one of its most interesting therapeutic properties. This effect is considered responsible for the effectiveness of SCS in peripheral ischemia, and at least some cases of complex regional pain syndrome. The sympatholytic effect has also been considered part of the management of other chronic pain states such as failed back surgery syndrome, phantom pain, diabetic neuropathy, and postherpetic neuralgia. In general, SCS is part of an overall treatment strategy and is used only after the more conservative treatments have failed. The concept of SCS has evolved rapidly following the technological advances that have produced leads with multiple contact electrodes and battery systems. The current prevalence of patients with chronic pain requiring treatment other than conventional medical management has significantly increased and so has been the need for SCS. With the cost benefit analysis showing significant support for SCS, it may be appropriate to offer this as an effective alternative treatment for these patients.

Spinal Cord Stimulation: Clinical Efficacy and Potential Mechanisms.

PubMed

Sdrulla, Andrei D; Guan, Yun; Raja, Srinivasa N

2018-03-11

Spinal cord stimulation (SCS) is a minimally invasive therapy used for the treatment of chronic neuropathic pain. SCS is a safe and effective alternative to medications such as opioids, and multiple randomized controlled studies have demonstrated efficacy for difficult-to-treat neuropathic conditions such as failed back surgery syndrome. Conventional SCS is believed mediate pain relief via activation of dorsal column Aβ fibers, resulting in variable effects on sensory and pain thresholds, and measurable alterations in higher order cortical processing. Although potentiation of inhibition, as suggested by Wall and Melzack's gate control theory, continues to be the leading explanatory model, other segmental and supraspinal mechanisms have been described. Novel, non-standard, stimulation waveforms such as high-frequency and burst have been shown in some studies to be clinically superior to conventional SCS, however their mechanisms of action remain to be determined. Additional studies are needed, both mechanistic and clinical, to better understand optimal stimulation strategies for different neuropathic conditions, improve patient selection and optimize efficacy. © 2018 World Institute of Pain.

Single laser pulse compression via strongly coupled stimulated Brillouin scattering in plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, H.; Wu, Z. H.; Zhang, Z. M.

2016-07-15

Laser amplification in plasma, including stimulated Raman scattering amplification and strongly coupled stimulated Brillouin scattering (sc-SBS) amplification, is very promising to generate ultrahigh-power and ultrashort laser pulses. But both are quite complex in experiments: at least three different laser pulses must be prepared; temporal delay and spatial overlap of these three pulses are difficult. We propose a single pulse compression scheme based on sc-SBS in plasma. Only one moderately long laser is applied, the front part of which ionizes the gas to produced plasma, and gets reflected by a plasma mirror at the end of the gas channel. The reflectedmore » front quickly depletes the remaining part of the laser by sc-SBS in the self-similar regime. The output laser is much stronger and shorter. This scheme is at first considered theoretically, then validated by using 1D PIC simulations.« less

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Effect of laser light on the kinetics of the oxidation of titanium films during heat treatment

NASA Astrophysics Data System (ADS)

Chaplanov, A. M.; Shibko, A. N.

1993-02-01

The application of laser light to materials in a heated state stimulates oxidation-reduction reactions in them. The illumination of titanium films by a beam of photons with hν =1.96 eV during annealing in vacuum stimulates photochemical processes of a nonthermal nature in addition to recrystallization.

Transcranial magnetic stimulation of the brain: guidelines for pain treatment research

PubMed Central

Klein, Max M.; Treister, Roi; Raij, Tommi; Pascual-Leone, Alvaro; Park, Lawrence; Nurmikko, Turo; Lenz, Fred; Lefaucheur, Jean-Pascal; Lang, Magdalena; Hallett, Mark; Fox, Michael; Cudkowicz, Merit; Costello, Ann; Carr, Daniel B.; Ayache, Samar S.; Oaklander, Anne Louise

2015-01-01

Abstract Recognizing that electrically stimulating the motor cortex could relieve chronic pain sparked development of noninvasive technologies. In transcranial magnetic stimulation (TMS), electromagnetic coils held against the scalp influence underlying cortical firing. Multiday repetitive transcranial magnetic stimulation (rTMS) can induce long-lasting, potentially therapeutic brain plasticity. Nearby ferromagnetic or electronic implants are contraindications. Adverse effects are minimal, primarily headaches. Single provoked seizures are very rare. Transcranial magnetic stimulation devices are marketed for depression and migraine in the United States and for various indications elsewhere. Although multiple studies report that high-frequency rTMS of the motor cortex reduces neuropathic pain, their quality has been insufficient to support Food and Drug Administration application. Harvard's Radcliffe Institute therefore sponsored a workshop to solicit advice from experts in TMS, pain research, and clinical trials. They recommended that researchers standardize and document all TMS parameters and improve strategies for sham and double blinding. Subjects should have common well-characterized pain conditions amenable to motor cortex rTMS and studies should be adequately powered. They recommended standardized assessment tools (eg, NIH's PROMIS) plus validated condition-specific instruments and consensus-recommended metrics (eg, IMMPACT). Outcomes should include pain intensity and qualities, patient and clinician impression of change, and proportions achieving 30% and 50% pain relief. Secondary outcomes could include function, mood, sleep, and/or quality of life. Minimum required elements include sample sources, sizes, and demographics, recruitment methods, inclusion and exclusion criteria, baseline and posttreatment means and SD, adverse effects, safety concerns, discontinuations, and medication-usage records. Outcomes should be monitored for at least 3 months after initiation with prespecified statistical analyses. Multigroup collaborations or registry studies may be needed for pivotal trials. PMID:25919472

Comparative clinical study using laser and LED-therapy for orofacial pain relief: dentin hypersensitivity and cervicogenic headache

NASA Astrophysics Data System (ADS)

Lizarelli, Rosane F. Z.; Pizzo, Renata C. A.; Florez, Fernando L. E.; Grecco, Clovis; Speciali, Jose G.; Bagnato, Vanderlei S.

2015-06-01

Considering several clinical situations, low intensity laser therapy has been widely applied in pain relief or analgesia mechanism. With the advent of new LED-based (light emitting diode) light sources, the need of further clinical experiments aiming to compare the effectiveness among them is paramount. The LED system therapeutic use can be denominated as LEDT - Light Emitting Diode Therapy. This study proposed two clinical evaluations of pain relief effect: to dentin hypersensitivity and to cervicogenic headache using different sources of lasers (low and high intensity) and light emitting diodes (LEDs), one emitting at the spectral band of red (630+/- 5nm) and the other one at infrared band (880+/- 5nm). Two different clinical studies were performed and presented interesting results. Considering dentin hypersensitivity, red and infrared led were so effective than the control group (high intensity laser system); by the other side, considering cervicogenic headache, control group (infrared laser) was the best treatment in comparison to red and infrared led system.

Tri-wave laser therapy for spinal cord injury, neuropathic pain management, and restoration of motor function

NASA Astrophysics Data System (ADS)

Chariff, Mark D.; Olszak, Peter

2015-03-01

A laser therapy device using three combined wavelengths 532nm, 808nm, and 1064nm has been demonstrated in clinical studies. Primarily, therapeutic lasers have used wavelengths in the ranges of 632nm through 1064nm, where the optical density (OD) < 5, to achieve pain relief and tissue regeneration. Conventional wisdom would argue against using wavelengths in the region of 532nm, due to poor penetration (OD ~ 8); however, the author's observations are to the contrary. The 532nm light is efficiently absorbed by chromophores such as oxyhemoglobin, deoxyhemoglobin, and cytochrome c oxidase thereby providing energy to accelerate the healing process. The 808nm light is known to result in Nitric Oxide production thereby reducing inflammation and oxidative stress. All three laser wavelengths likely contribute to pain relief by inhibiting nerve conduction; however, the 1064nm has the deepest penetration. Through the use of this device on over 1000 patients with a variety of acute and chronic neuro-musculoskeletal disorders, the author observed that a majority of these individuals experienced rapid relief from their presenting conditions and most patients reported a tingling sensation upon irradiation. Patient testimonials and thermal images have been collected to document the results of the laser therapy. These studies demonstrate the ability of laser therapy to rapidly alleviate pain from both acute and chronic conditions.

Pain perception studies in tension-type headache.

PubMed

Bezov, David; Ashina, Sait; Jensen, Rigmor; Bendtsen, Lars

2011-02-01

Tension-type headache (TTH) is a disorder with high prevalence and significant impact on society. Understanding of pathophysiology of TTH is paramount for development of effective treatments and prevention of chronification of TTH. Our aim was to review the findings from pain perception studies of pathophysiology of TTH as well as to review the research of pathophysiology of TTH. Pain perception studies such as measurement of muscle tenderness, pain detection thresholds, pain tolerance thresholds, pain response to suprathreshold stimulation, temporal summation and diffuse noxious inhibitory control (DNIC) have played a central role in elucidating the pathophysiology of TTH. It has been demonstrated that continuous nociceptive input from peripheral myofascial structures may induce central sensitization and thereby chronification of the headache. Measurements of pain tolerance thresholds and suprathreshold stimulation have shown presence of generalized hyperalgesia in chronic tension-type headache (CTTH) patients, while DNIC function has been shown to be reduced in CTTH. One imaging study showed loss of gray matter structures involved in pain processing in CTTH patients. Future studies should aim to integrate pain perception and imaging to confirm this finding. Pharmacological studies have shown that drugs like tricyclic anti-depressant amitriptyline and nitric oxide synthase inhibitors can reverse central sensitization and the chronicity of headache. Finally, low frequency electrical stimulation has been shown to rapidly reverse central sensitization and may be a new modality in treatment of CTTH and other chronic pain disorders. © 2010 American Headache Society.

Nanosecond laser pulse stimulation of spiral ganglion neurons and model cells.

PubMed

Rettenmaier, Alexander; Lenarz, Thomas; Reuter, Günter

2014-04-01

Optical stimulation of the inner ear has recently attracted attention, suggesting a higher frequency resolution compared to electrical cochlear implants due to its high spatial stimulation selectivity. Although the feasibility of the effect is shown in multiple in vivo experiments, the stimulation mechanism remains open to discussion. Here we investigate in single-cell measurements the reaction of spiral ganglion neurons and model cells to irradiation with a nanosecond-pulsed laser beam over a broad wavelength range from 420 nm up to 1950 nm using the patch clamp technique. Cell reactions were wavelength- and pulse-energy-dependent but too small to elicit action potentials in the investigated spiral ganglion neurons. As the applied radiant exposure was much higher than the reported threshold for in vivo experiments in the same laser regime, we conclude that in a stimulation paradigm with nanosecond-pulses, direct neuronal stimulation is not the main cause of optical cochlea stimulation.

Mechanism of Activation of Enteric Nociceptive Neurons via Interaction of TLR4 and TRPV1 Receptors.

PubMed

Filippova, L V; Fedorova, A V; Nozdrachev, A D

2018-03-01

Evidence obtained by immunohistochemical double labeling and confocal laser scanning microscopy suggests that capsaicin, a ligand of the TRPV1 nociceptive vanilloid receptor, increases the number of TLR4-positive neurons in the rat colon myenteric plexus. In colitis caused by trinitrobenzene sulfonate, an increase in TRPV1 expression was more significant in both plexuses. Specific inhibitor of the TLR4 (C34) pattern-recognition receptor reduces TRPV1 expression in enteric neurons of both intact rats and rats with induced acute colitis. Thus, stimulation of nociceptive neurons by means of direct activation of their receptors of innate immunity (TLR4) is one of the possible mechanisms underlying the visceral pain in bacterial invasion and inflammatory bowel diseases.

Does Transcranial Direct Current Stimulation Combined with Peripheral Electrical Stimulation Have an Additive Effect in the Control of Hip Joint Osteonecrosis Pain Associated with Sickle Cell Disease? A Protocol for a One-Session Double Blind, Block-Randomized Clinical Trial.

PubMed

Lopes, Tiago da Silva; Silva, Wellington Dos Santos; Ribeiro, Sânzia B; Figueiredo, Camila A; Campbell, Fernanda Q; Daltro, Gildasio de Cerqueira; Valenzuela, Antônio; Montoya, Pedro; Lucena, Rita de C S; Baptista, Abrahão F

2017-01-01

Chronic pain in Sickle Cell Disease (SCD) is probably related to maladaptive plasticity of brain areas involved in nociceptive processing. Transcranial Direct Current Stimulation (tDCS) and Peripheral Electrical Stimulation (PES) can modulate cortical excitability and help to control chronic pain. Studies have shown that combined use of tDCS and PES has additive effects. However, to date, no study investigated additive effects of these neuromodulatory techniques on chronic pain in patients with SCD. This protocol describes a study aiming to assess whether combined use of tDCS and PES more effectively alleviate pain in patients with SCD compared to single use of each technique. The study consists of a one-session double blind, block-randomized clinical trial (NCT02813629) in which 128 participants with SCD and femoral osteonecrosis will be enrolled. Stepwise procedures will occur on two independent days. On day 1, participants will be screened for eligibility criteria. On day 2, data collection will occur in four stages: sample characterization, baseline assessment, intervention, and post-intervention assessment. These procedures will last ~5 h. Participants will be divided into two groups according to homozygous for S allele (HbSS) ( n = 64) and heterozygous for S and C alleles (HbSC) ( n = 64) genotypes. Participants in each group will be randomly assigned, equally, to one of the following interventions: (1) active tDCS + active PES; (2) active tDCS + sham PES; (3) sham tDCS + active PES; and (4) sham tDCS + sham PES. Active tDCS intervention will consist of 20 min 2 mA anodic stimulation over the primary motor cortex contralateral to the most painful hip. Active PES intervention will consist of 30 min sensory electrical stimulation at 100 Hz over the most painful hip. The main study outcome will be pain intensity, measured by a Visual Analogue Scale. In addition, electroencephalographic power density, cortical maps of the gluteus maximus muscle elicited by Transcranial Magnetic Stimulation (TMS), serum levels of Brain-derived Neurotrophic Factor (BDNF), and Tumor Necrosis Factor (TNF) will be assessed as secondary outcomes. Data will be analyzed using ANOVA of repeated measures, controlling for confounding variables.

Comparison of the effect of diode laser versus intense pulsed light in axillary hair removal.

PubMed

Ormiga, Patricia; Ishida, Cleide Eiko; Boechat, Alvaro; Ramos-E-Silva, Marcia

2014-10-01

Devices such as diode laser and intense pulsed light (IPL) are in constant development aiming at permanent hair removal, but there are few comparative studies between these technologies. The objective was to comparatively assess axillary hair removal performed by diode laser and IPL and to obtain parameters of referred pain and evolution response for each method. A comparative prospective, double-blind, and randomized study of axillary hair removal performed by the diode laser and IPL was conducted in 21 females. Six sessions were held with application of the diode laser in one axilla and the IPL in the other, with intervals of 30 days and follow-up of 6 months after the last session. Clinical photographs and digital dermoscopy for hair counts in predefined and fixed fields of the treated areas were performed before, 2 weeks after the sixth session, and 6 months after the end of treatment. A questionnaire to assess the pain was applied. The number of hair shafts was significantly reduced with the diode laser and IPL. The diode laser was more effective, although more painful than the IPL. No serious, adverse, or permanent effects were observed with both technologies. Both diode laser and the IPL are effective, safe, and able to produce lasting results in axillary hair removal.

Efficacy of Nd:YAG and GaAlAs lasers in comparison to 2% fluoride gel for the treatment of dentinal hypersensitivity.

PubMed

Soares, Marília De Lima; Porciúncula, Geane Bandeira; Lucena, Mara Ilka Holanda Medeiros De; Gueiros, Luiz Alcino Monteiro; Leão, Jair Carneiro; Carvalho, Alessandra De Albuquerque Tavares

2016-01-01

Lasers demonstrate excellent therapeutic action and are often employed in dentistry for the treatment of diverse clinical conditions. The aim of this study was to compare the efficacy of neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser, gallium-aluminum-arsenide (GaAlAs) laser, and 2% neutral fluoride gel in the treatment of dentinal hypersensitivity. Twenty-three patients were evaluated, involving a total of 48 quadrants with at least 1 tooth with dentinal hypersensitivity (89 teeth total). Pain intensity was recorded on a visual analog scale at the time of clinical examination (baseline), immediately after treatment, and 1 week posttreatment. Teeth were treated with 60 seconds of 2% neutral fluoride gel application or 60 seconds of laser treatment-Nd:YAG laser at a distance of 0.5 cm (unfocused; 1 W and 10 Hz for 60 seconds, perpendicular to the cervical surfaces) or GaAlAs laser in contact (40 mW; 4 J/cm²; spot: 0.028 cm²; 15 seconds per point on 4 points [mesial, medial, distal, and apical])-as well as sham treatments so that patients remained blind to their treatment group. All treatments provided adequate pain reduction immediately posttreatment, but laser treatments resulted in significantly greater reductions in pain intensity.

[Combined use of various laser radiations in thoracic surgery in experimental studies].

PubMed

Ismailov, D A; Khoroshaev, V A; Shishkin, M A; Baĭbekov, I M

1993-01-01

The impact of various types of low-intensive lasers (He-Ne, copper vapour, ultraviolet, infrared, infrared gallium arsenide) on healing of a wound made by CO2 laser at an output power of 25 W was studied in an experiment on 120 albino Wistar rats. It was found that a concurrent application of high- and low-intensive lasers resulted in acceleration of reparative processes in the lung, stimulating the healing of laser-induced wounds. The infrared gallium arsenide laser was demonstrated to be the best tool in stimulating the healing process.

Association of Transcutaneous Electrical Nerve Stimulation and Hypnosis

ClinicalTrials.gov

2017-08-02

Limbs Arthrosis; Non Arthrosic Limbs Arthralgia; Chronic Lomboradiculalgia; Chronic Back Pain; Cervical Radiculopathy; Post-herpetic Neuralgia; Post-surgical Peripheral Neuropathic Pain; Post Trauma Neuropathic Pain; Complex Regional Pain Syndrome Type I or II; Tendinopathy

MEG Can Map Short and Long-Term Changes in Brain Activity following Deep Brain Stimulation for Chronic Pain

PubMed Central

Mohseni, Hamid R.; Smith, Penny P.; Parsons, Christine E.; Young, Katherine S.; Hyam, Jonathan A.; Stein, Alan; Stein, John F.; Green, Alexander L.; Aziz, Tipu Z.; Kringelbach, Morten L.

2012-01-01

Deep brain stimulation (DBS) has been shown to be clinically effective for some forms of treatment-resistant chronic pain, but the precise mechanisms of action are not well understood. Here, we present an analysis of magnetoencephalography (MEG) data from a patient with whole-body chronic pain, in order to investigate changes in neural activity induced by DBS for pain relief over both short- and long-term. This patient is one of the few cases treated using DBS of the anterior cingulate cortex (ACC). We demonstrate that a novel method, null-beamforming, can be used to localise accurately brain activity despite the artefacts caused by the presence of DBS electrodes and stimulus pulses. The accuracy of our source localisation was verified by correlating the predicted DBS electrode positions with their actual positions. Using this beamforming method, we examined changes in whole-brain activity comparing pain relief achieved with deep brain stimulation (DBS ON) and compared with pain experienced with no stimulation (DBS OFF). We found significant changes in activity in pain-related regions including the pre-supplementary motor area, brainstem (periaqueductal gray) and dissociable parts of caudal and rostral ACC. In particular, when the patient reported experiencing pain, there was increased activity in different regions of ACC compared to when he experienced pain relief. We were also able to demonstrate long-term functional brain changes as a result of continuous DBS over one year, leading to specific changes in the activity in dissociable regions of caudal and rostral ACC. These results broaden our understanding of the underlying mechanisms of DBS in the human brain. PMID:22675503

Tripolar spinal cord stimulation for the treatment of abdominal pain associated with irritable bowel syndrome.

PubMed

Rana, Maunak V; Knezevic, Nebojsa Nick

2013-01-01

The objective of this case report is to describe the use of transverse tripolar dorsal column stimulation in a patient with a history of irritable bowel syndrome (IBS) associated with abdominal pain resistant to conservative treatments. We report a 36-year-old man who presented to the pain clinic with an eight-year history of IBS (constipation predominant with occasional diarrheal episodes), with "crampy and sharp" abdominal pain. He also had nonradicular thoracic spine pain due to thoracic scoliosis. Both pains were affecting his ability to function as an attorney. Prior conservative therapy, including psychologic treatment, antidepressants, and opioids, was without any benefits. The use of a spinal cord stimulator (SCS) was discussed with the patient. The procedure was performed after Institutional Review Board approval. A tripolar SCS was implanted at the T8 level using one-eight contact and two-four contact percutaneous leads based on paresthesia reproduction of patient's areas of discomfort. This tripolar spinal cord stimulation provided relief of abdominal and thoracic pain, and better management of gastrointestinal symptoms. The patient was followed-up for one year, and his quality of life also was improved via the IBS-Severity Scoring System quality of life tool. The use of the tripolar SCS in this patient provided relief of abdominal and thoracic spine pain, regulated bowel habits, and improved the patient's quality of life. We believe that the use of SCS should be considered as a treatment option in patients with IBS when all conservative treatments failed. © 2012 International Neuromodulation Society.

Differential effects of bifrontal and occipital nerve stimulation on pain and fatigue using transcranial direct current stimulation in fibromyalgia patients.

PubMed

To, Wing Ting; James, Evan; Ost, Jan; Hart, John; De Ridder, Dirk; Vanneste, Sven

2017-07-01

Fibromyalgia is a disorder characterized by widespread musculoskeletal pain frequently accompanied by other symptoms such as fatigue. Moderate improvement from pharmacological and non-pharmacological treatments have proposed non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) to the occipital nerve (more specifically the C2 area) or to the dorsolateral prefrontal cortex (DLPFC) as potential treatments. We aimed to explore the effectiveness of repeated sessions of tDCS (eight sessions) targeting the C2 area and DLPFC in reducing fibromyalgia symptoms, more specifically pain and fatigue. Forty-two fibromyalgia patients received either C2 tDCS, DLPFC tDCS or sham procedure (15 C2 tDCS-11 DLPFC tDCS-16 sham). All groups were treated with eight sessions (two times a week for 4 weeks). Our results show that repeated sessions of C2 tDCS significantly improved pain, but not fatigue, in fibromyalgia patients, whereas repeated sessions of DLPFC tDCS significantly improved pain as well as fatigue. This study shows that eight sessions of tDCS targeting the DLPFC have a more general relief in fibromyalgia patients than when targeting the C2 area, suggesting that stimulating different targets with eight sessions of tDCS can lead to benefits on different symptom dimensions of fibromyalgia.

Exploring the Mechanisms of Exercise-Induced Hypoalgesia Using Somatosensory and Laser Evoked Potentials.

PubMed

Jones, Matthew D; Taylor, Janet L; Booth, John; Barry, Benjamin K

2016-01-01

Exercise-induced hypoalgesia is well described, but the underlying mechanisms are unclear. The aim of this study was to examine the effect of exercise on somatosensory evoked potentials, laser evoked potentials, pressure pain thresholds and heat pain thresholds. These were recorded before and after 3-min of isometric elbow flexion exercise at 40% of the participant's maximal voluntary force, or an equivalent period of rest. Exercise-induced hypoalgesia was confirmed in two experiments (Experiment 1-SEPs; Experiment 2-LEPs) by increased pressure pain thresholds at biceps brachii (24.3 and 20.6% increase in Experiment 1 and 2, respectively; both d > 0.84 and p < 0.001) and first dorsal interosseous (18.8 and 21.5% increase in Experiment 1 and 2, respectively; both d > 0.57 and p < 0.001). In contrast, heat pain thresholds were not significantly different after exercise (forearm: 10.8% increase, d = 0.35, p = 0.10; hand: 3.6% increase, d = 0.06, p = 0.74). Contrasting effects of exercise on the amplitude of laser evoked potentials (14.6% decrease, d = -0.42, p = 0.004) and somatosensory evoked potentials (10.9% increase, d = -0.02, p = 1) were also observed, while an equivalent period of rest showed similar habituation (laser evoked potential: 7.3% decrease, d = -0.25, p = 0.14; somatosensory evoked potential: 20.7% decrease, d = -0.32, p = 0.006). The differential response of pressure pain thresholds and heat pain thresholds to exercise is consistent with relative insensitivity of thermal nociception to the acute hypoalgesic effects of exercise. Conflicting effects of exercise on somatosensory evoked potentials and laser evoked potentials were observed. This may reflect non-nociceptive contributions to the somatosensory evoked potential, but could also indicate that peripheral nociceptors contribute to exercise-induced hypoalgesia.

Electrical stimulation as a treatment intervention to improve function, edema or pain following acute lateral ankle sprains: A systematic review.

PubMed

Feger, Mark A; Goetschius, John; Love, Hailey; Saliba, Sue A; Hertel, Jay

2015-11-01

The purpose of this systematic review was to assess whether electrical stimulation (ES), when used in conjunction with a standard treatment, can reduce levels of functional impairment, edema, and pain compared to a standard treatment alone, in patients following a lateral ankle sprain. We searched PubMed, CINAHL, SportDiscus, and Medline (OVID) databases through June 2014 using the terms "ankle sprain or ankle sprains or ligament injury or ligamentous injury," and "electric stimulation or electric stimulation or electrotherapy." Our search identified four randomized control trials, of which, neuromuscular ES and high-voltage pulsed stimulation were the only two ES modalities utilized. Effect sizes and 95% confidence intervals (CI) were estimated using Cohen's d for comparison between treatment groups. Three of four effect sizes for function had 95% CI that crossed zero. Twenty-four of the thirty-two effect sizes for edema had 95% CI that crossed zero. All effect sizes for pain had 95% CI that crossed zero. Therefore, the use of ES is not recommended as a means to improve function, reduce edema, or decrease pain in the treatment of acute lateral ankle sprains. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thoracic Radiculopathy following Spinal Cord Stimulator Implantation Treated with Corticosteroids.

PubMed

Ghosh, Ritam; Holland, Ryan; Mammis, Antonios

2017-04-01

Spinal cord stimulation has been used since 1967 to manage chronic neuropathic pain. Although effective, the literature describes the complication rate to be as high as 35%. One rare complication following spinal cord stimulator (SCS) implantation is the development of radicular pain. We present a case series of 2 patients implanted with SCSs who developed thoracic radiculopathy following implantation that resolved with corticosteroids. Although this complication was previously thought to require surgical intervention, this case series describes the use of corticosteroids to resolve postimplantation thoracic radiculopathy. Two patients were studied in this case series who received permanent thoracic implantation of a paddle lead SCS. Several days later, both developed back pain radiating toward the umbilicus in a dermatomal pattern consistent with thoracic radiculopathy. Corticosteroids were administered to relieve this pain. One received 6 mg dexamethasone intravenously every 6 hours followed by an oral dexamethasone taper for 1 week. The other was treated with an oral methylprednisolone taper for 2 weeks. Upon follow-up, both patients no longer complained of the thoracic radiculopathy and were satisfied with the pain relief the stimulators provided. In conclusion, postsurgical radicular pain is a rare but troubling complication of SCS implantation. In order to avoid further surgical complications or the need to explant a device that provides satisfactory paresthesia coverage, pharmacologic management is desirable. This case series has demonstrated that the use of corticosteroids can effectively resolve postimplantation thoracic radicular pain in a specific subgroup of patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Measurements of jaw movements and TMJ pain intensity in patients treated with GaAlAs laser.

PubMed

Mazzetto, Marcelo Oliveira; Hotta, Takami Hirono; Pizzo, Renata Campi de Andrade

2010-01-01

The aim of this study was to evaluate the effectiveness of low-level laser therapy (LLLT) on the improvement of the mandibular movements and painful symptoms in individuals with temporomandibular disorders (TMD). Forty patients were randomly divided into two groups (n=20): Group 1 received the effective dose (GaAlAs laser λ 830 nm, 40 mW, 5J/cm²) and Group 2 received the placebo application (0 J/cm²), in continuous mode on the affected condyle lateral pole: superior, anterior, posterior, and posterior-inferior, twice a week during 4 weeks. Four evaluations were performed: E1 (before laser application), E2 (right after the last application), E3 (one week after the last application) and E4 (30 days after the last application). The Kruskal-Wallis test showed significant more improvements (p<0.01) in painful symptoms in the treated group than in the placebo group. A significant improvement in the range of mandibular movements was observed when the results were compared between the groups at E4. Laser application can be a supportive therapy in the treatment of TMD, since it resulted in the immediate decrease of painful symptoms and increased range of mandibular movements in the treated group. The same results were not observed in the placebo group.

Meta-analysis of transcutaneous electrical nerve stimulation for relief of spinal pain.

PubMed

Resende, L; Merriwether, E; Rampazo, É P; Dailey, D; Embree, J; Deberg, J; Liebano, R E; Sluka, K A

2018-04-01

We conducted a systematic review and meta-analysis analysing the existing data on transcutaneous electrical nerve stimulation (TENS) or interferential current (IFC) for chronic low back pain (CLBP) and/or neck pain (CNP) taking into account intensity and timing of stimulation, examining pain, function and disability. Seven electronic databases were searched for TENS or IFC treatment in non-specific CLBP or CNP. Four reviewers independently selected randomized controlled trials (RCTs) of TENS or IFC intervention in adult individuals with non-specific CLBP or CNP. Primary outcomes were for self-reported pain intensity and back-specific disability. Two reviewers performed quality assessment, and two reviewers extracted data using a standardized form. Nine RCTs were selected (eight CLBP; one CNP), and seven studies with complete data sets were included for meta-analysis (655 participants). For CLBP, meta-analysis shows TENS/IFC intervention, independent of time of assessment, was significantly different from placebo/control (p < 0.02). TENS/IFC intervention was better than placebo/control, during therapy (p = 0.02), but not immediately after therapy (p = 0.08), or 1-3 months after therapy (p = 0.99). Analysis for adequate stimulation parameters was not significantly different, and there was no effect on disability. This systematic review provides inconclusive evidence of TENS benefits in low back pain patients because the quality of the studies was low, and adequate parameters and timing of assessment were not uniformly used or reported. Without additional high-quality clinical trials using sufficient sample sizes and adequate parameters and outcome assessments, the outcomes of this review are likely to remain unchanged. These data highlight the need for additional high-quality RCTs to examine the effects of TENS in CLBP. Trials should consider intensity of stimulation, timing of outcome assessment and assessment of pain, disability and function. © 2017 European Pain Federation - EFIC®.

Repetitive transcranial magnetic stimulation of the left premotor/dorsolateral prefrontal cortex does not have analgesic effect on central poststroke pain.

PubMed

de Oliveira, Rogério Adas Ayres; de Andrade, Daniel Ciampi; Mendonça, Melina; Barros, Rafael; Luvisoto, Tatiana; Myczkowski, Martin Luiz; Marcolin, Marco Antonio; Teixeira, Manoel Jacobsen

2014-12-01

Central poststroke pain (CPSP) is caused by an encephalic vascular lesion of the somatosensory pathways and is commonly refractory to current pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) can change thermal pain threshold toward analgesia in healthy subjects and has analgesic effects in acute postoperative pain as well as in fibromyalgia patients. However, its effect on neuropathic pain and in CPSP, in particular, has not been assessed. The aim of this prospective, double-blind, placebo-controlled study was to evaluate the analgesic effect of PMC/DLPFC rTMS in CPSP patients. Patients were randomized into 2 groups, active (a-) rTMS and sham (s-) rTMS, and were treated with 10 daily sessions of rTMS over the left PMC/DLPFC (10 Hz, 1,250 pulses/d). Outcomes were assessed at baseline, during the stimulation phase, and at 1, 2, and 4 weeks after the last stimulation. The main outcome was pain intensity changes measured by the visual analog scale on the last stimulation day compared to baseline. Interim analysis was scheduled when the first half of the patients completed the study. The study was terminated because of a significant lack of efficacy of the active arm after 21 patients completed the whole treatment and follow-up phases. rTMS of the left PMC/DLPFC did not improve pain in CPSP. The aim of this double-blind, placebo-controlled study was to evaluate the analgesic effects of rTMS to the PMC/DLPFC in CPSP patients. An interim analysis showed a consistent lack of analgesic effect, and the study was terminated. rTMS of the PMC/DLPFC is not effective in relieving CPSP. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

Differences in carbachol dose, pain condition, and sex following lateral hypothalamic stimulation.

PubMed

Holden, J E; Wang, E; Moes, J R; Wagner, M; Maduko, A; Jeong, Y

2014-06-13

Lateral hypothalamic (LH) stimulation produces antinociception in female rats in acute, nociceptive pain. Whether this effect occurs in neuropathic pain or whether male-female sex differences exist is unknown. We examined the effect of LH stimulation in male and female rats using conditions of nociceptive and neuropathic pain. Neuropathic groups received chronic constriction injury (CCI) to induce thermal hyperalgesia, a sign of neuropathic pain. Nociceptive rats were naive for CCI, but received the same thermal stimulus following LH stimulation. To demonstrate that CCI ligation produced thermal hyperalgesia, males and females received either ligation or sham surgery for control. Both males and females demonstrated significant thermal hyperalgesia following CCI ligation (p<0.05), but male sham surgery rats also showed a significant left-right difference not present in female sham rats. In the second experiment, rats randomly assigned to CCI or nociceptive groups were given one of three doses of the cholinergic agonist carbachol (125, 250, or 500 nmol) or normal saline for control, microinjected into the left LH. Paw withdrawal from a thermal stimulus (paw withdrawal latency; PWL) was measured every 5 min for 45 min. Linear mixed models analysis showed that males and females in both pain conditions demonstrated significant antinociception, with the 500-nmol dose producing the greatest effect across groups compared with controls for the left paw (p<0.05). Female CCI rats showed equivalent responses to the three doses, while male CCI rats showed more variability for dose. However, nociceptive females responded only to the 500-nmol dose, while nociceptive males responded to all doses (p<0.05). For right PWL, only nociceptive males showed a significant carbachol dose response. These findings are suggestive that LH stimulation produces antinociception in male and female rats in both nociceptive and neuropathic pain, but dose response differences exist based on sex and pain condition. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Efficacy of low-level laser therapy in the management of pain, facial swelling, and postoperative trismus after a lower third molar extraction. A preliminary study.

PubMed

López-Ramírez, Marta; Vílchez-Pérez, Miguel Angel; Gargallo-Albiol, Jordi; Arnabat-Domínguez, Josep; Gay-Escoda, Cosme

2012-05-01

Pain, swelling, and trismus are the most common complications after surgical removal of impacted lower third molars. The aim of this study was to evaluate the analgesic and anti-inflammatory effects of a low-level laser therapy (Laser Smile™, Biolase®, San Clemente, USA) applied to the wound appeared after the surgical removal of impacted lower third molars. A prospective, randomized, and double-blind study was undertaken in 20 healthy patients with two symmetrically impacted lower third molars. The application of a low-level laser was made randomly on one of the two sides after surgery. The experimental side received 5 J/cm(2) of energy density, a wavelength of 810 nm, and an output power of 0.5 W. On the control side, a handpiece was applied intraorally, but the laser was not activated. Evaluations of postoperative pain, trismus, and swelling were made. The sample consisted of 11 women and nine men, and mean age was 23.35 years (18-37). The pain level in the first hours after surgery was lower in the experimental side than in the placebo side, although without statistically significant differences (p = 0.258). Swelling and trismus at the 2nd and 7th postoperative days were slightly higher in the control side, although not statistically significant differences were detected (p > 0.05). The application of a low-level laser with the parameters used in this study did not show beneficial affects in reducing pain, swelling, and trismus after removal of impacted lower third molars.

Pharmacologic attenuation of cross-modal sensory augmentation within the chronic pain insula

PubMed Central

Harte, Steven E.; Ichesco, Eric; Hampson, Johnson P.; Peltier, Scott J.; Schmidt-Wilcke, Tobias; Clauw, Daniel J.; Harris, Richard E.

2016-01-01

Abstract Pain can be elicited through all mammalian sensory pathways yet cross-modal sensory integration, and its relationship to clinical pain, is largely unexplored. Centralized chronic pain conditions such as fibromyalgia are often associated with symptoms of multisensory hypersensitivity. In this study, female patients with fibromyalgia demonstrated cross-modal hypersensitivity to visual and pressure stimuli compared with age- and sex-matched healthy controls. Functional magnetic resonance imaging revealed that insular activity evoked by an aversive level of visual stimulation was associated with the intensity of fibromyalgia pain. Moreover, attenuation of this insular activity by the analgesic pregabalin was accompanied by concomitant reductions in clinical pain. A multivariate classification method using support vector machines (SVM) applied to visual-evoked brain activity distinguished patients with fibromyalgia from healthy controls with 82% accuracy. A separate SVM classification of treatment effects on visual-evoked activity reliably identified when patients were administered pregabalin as compared with placebo. Both SVM analyses identified significant weights within the insular cortex during aversive visual stimulation. These data suggest that abnormal integration of multisensory and pain pathways within the insula may represent a pathophysiological mechanism in some chronic pain conditions and that insular response to aversive visual stimulation may have utility as a marker for analgesic drug development. PMID:27101425

Amplified stimulated emission in the NaK(D-X) band by high power copper vapor laser pumping

NASA Astrophysics Data System (ADS)

Dinev, S. G.; Hadjicristov, G. B.; Marazov, O.

1991-04-01

Using a 10 W copper vapor laser we have studied a stimulated emission at 520-570 nm in the D-X electronic transition of the NaK heteronuclear molecule. The influence of the cavity configuration on the bound-bound stimulated lines is considered.

Amplified stimulated emission in the NaK( D→ X) band by high power copper vapor laser pumping

NASA Astrophysics Data System (ADS)

Dinev, S. G.; Hadjichristov, G. B.; Marazov, O.

1991-04-01

Using a 10 W copper vapor laser we have studied a stimulated emission at 520 570 nm in the D→ X electronic transition of the NaK heteronuclear molecule. The influence of the cavity configuration on the bound-bound stimulated lines is considered.

Use of tens in pain management: part two--how to use tens.

PubMed

Poole, Debbie

Transcutaneous electrical nerve stimulation is widely used in pain management but its effectiveness depends on the stimulation being targeted appropriately. This article, the second in a two-part series, outlines how to set up and use a TENS machine to achieve the most effective results.

Vascular and Psychophysical Effects of Topical Capsaicin Application to Orofacial Tissues

PubMed Central

Boudreau, Shellie A.; Wang, Kelun; Svensson, Peter; Sessle, Barry J.; Arendt-Nielsen, Lars

2011-01-01

Aims To characterize and contrast human sensory and vascular changes produced by topical application of the algesic chemical capsaicin to the glabrous lips and tongue. Methods Applications of 1% capsaicin or vehicle cream to the glabrous lips and tongue were randomized between two two-trial sessions. The capsaicin trial followed the vehicle trial for each session. Before and 5, 15, and 30 minutes after capsaicin or vehicle cream application, six parameters were recorded from the glabrous lips or the tongue dorsum: (1) burning pain intensity, as measured on a visual analog scale; (2) burning pain area, as indicated by subjects on an orofacial drawing; (3) mechanical sensitivity, as measured by a von Frey filament; (4) visual flare; (5) blood flow and temperature, as measured by laser-Doppler imaging and thermography, respectively; and (6) areas of increased temperature (hot spots), as calculated by a digital tracer from the thermographs. Data were analyzed by ANOVAs and Pearson’s correlations. Results Compared to vehicle application, capsaicin elicited burning pain, increases in blood flow and temperature, but no change in mechanical sensitivity in the glabrous lips or tongue. Greater increases in blood flow and temperature paralleled more intense burning pain and larger areas of perceived pain for the lips compared to the tongue. The location of distinct areas of increased temperature within the orofacial area differed between the capsaicin-lip and capsaicin-tongue trials. Conclusion The several differences between these responses to noxious stimulation of the glabrous lips and tongue may have implications for examinations of orofacial somatosensory functions. PMID:19639105

Comparison of three pulsed infrared lasers for optical stimulation of the rat prostate cavernous nerves

NASA Astrophysics Data System (ADS)

Stahl, Charlotte S. D.; Tozburun, Serhat; Hutchens, Thomas C.; Lagoda, Gwen A.; Burnett, Arthur L.; Keller, Matthew D.; Fried, Nathaniel M.

2013-03-01

Optical nerve stimulation (ONS) is being explored for identification and preservation of the cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. This study compares three pulsed infrared lasers to determine whether differences in spectral linewidth and/or temporal pulse profile influence successful ONS of CN. Infrared laser radiation from the Capella diode laser (1873 nm, 5 ms, 10 Hz), Thulium fiber laser (TFL) (1873 nm, 5 ms, 10 Hz), and solid-state Holmium:YAG laser (2120 nm, 200 μs, 5 Hz) were transmitted through 400-μm-corediameter optical fibers, producing a 1-mm-diameter-spot on the nerve surface. Successful ONS was judged by an intracavernous pressure (ICP) response in the penis (n =10 rats) during a total stimulation time of 30 s. The narrow linewidth TFL (Δλ 0.5 nm) and broad linewidth Capella laser (Δλ 12 nm) performed similarly, producing ICP responses with a threshold radiant exposure of 0.45 J/cm2, and ICP response times of 12-17 s, while the Holmium laser stimulated at 0.59 J/cm2, and ICP response times of about 14-28 s. All three lasers demonstrated successful ONS of CN. ICP response time was dependent on the rate of energy deposition into the CN, rather than linewidth or temporal pulse profile.

Integrated Approach for Pain Management in Parkinson Disease.

PubMed

Geroin, Christian; Gandolfi, Marialuisa; Bruno, Veronica; Smania, Nicola; Tinazzi, Michele

2016-04-01

Pain, one of the most frequent nonmotor symptoms of Parkinson disease (PD), is recognized as an important component of the illness that adversely affects patient quality of life. The aims of this review are to summarize the current knowledge on the clinical assessment and to provide a detailed overview of the evidence-based pharmacologic and nonpharmacologic approaches to treating pain. Results of a literature search include studies investigating pain/sensory abnormalities in PD. The effects of levodopa administration, deep brain stimulation (DBS), pallidotomy, spinal cord stimulation, rehabilitation, and complementary/alternative medicine are reviewed critically. PD patients have altered pain and sensory thresholds; levodopa and DBS improve pain and change sensory abnormalities toward normal levels through antinociceptive and/or modulatory effects that remain unknown. A wide range of nonpharmacologic approaches require further investigation. A multidisciplinary approach is fundamental in managing pain syndromes in PD.

Laser discrimination by stimulated emission of a phosphor

NASA Technical Reports Server (NTRS)

Mathur, V. K.; Chakrabarti, K.

1991-01-01

A method for discriminating sources of UV, near infrared, and far infrared laser radiation was discovered. This technology is based on the use of a single magnesium sulfide phosphor doubly doped with rare earth ions, which is thermally/optically stimulated to generate colors correlatable to the incident laser radiation. The phosphor, after initial charging by visible light, exhibits green stimulated luminescence when exposed to a near infrared source (Nd: YAG laser). On exposure to far infrared sources (CO2 laser) the phosphor emission changes to orange color. A UV laser produces both an orange red as well as green color. A device using this phosphor is useful for detecting the laser and for discriminating between the near infrared, far infrared, and UV lasers. The technology is also capable of infrared laser diode beam profiling since the radiation source leaves an imprint on the phosphor that can be photographed. Continued development of the technology offers potential for discrimination between even smaller bandwidths within the infrared spectrum, a possible aid to communication or wavemixing devices that need to rapidly identify and process optical signals.

Nd:YAP laser pulse compression by three-stage transient stimulated Brillouin and Raman scattering

NASA Astrophysics Data System (ADS)

Kubeček, V.; Hamal, K.; Procházka, I.; Buzelis, R.; Girdauskas, V.; Dementiev, A.

1991-08-01

There is a continuous effort to generate stable, powerful picosecond laser pulses for application in spectroscopy, nonlinear optics and parametric light generation, as well. One of the possible methods is the compression of longer nanosecond laser pulses by stimulated Brillouin and stimulated Raman scattering. The advantages of such a technique, in comparison to the used mode locked picosecond lasers, are as follows: the absence of the active and/or passive mode lockers used to generate a train of picosecond pulses, and the absence of a fast electrooptical shutter used to select a single pulse from a train of pulses. The application of stimulated Brillouin and stimulated Raman scattering permits to generate picosecond pulses in the wavelength regions not covered by mode locked lasers. Of special interest is the wavelength region of 0·8 μm, which may be amplified by the attractive Titanium Sapphire lasers. In this paper we are summarizing our results in theoretical modelling and in real generation of picosecond pulses by means of cascaded stimulated Brillouin and Raman scattering. The models of scattering processes have been investigated. The stable generation of 5, 7, 3 picosecond pulses have been optimized for the wavelengths of 0·8, 0·64 and 0·54 μm, respectively. In all these cases, the pulses exhibited the far field pattern close to Gaussian, with the pulse energy ranging from 0·2 to 1 mJ.

Microcurrent Point Stimulation Applied to Lower Back Acupuncture Points for the Treatment of Nonspecific Neck Pain.

PubMed

Armstrong, Kelly; Gokal, Raman; Chevalier, Antoine; Todorsky, William; Lim, Mike

2017-04-01

Although acupuncture and microcurrent are widely used for chronic pain, there remains considerable controversy as to their therapeutic value for neck pain. We aimed to determine the effect size of microcurrent applied to lower back acupuncture points to assess the impact on the neck pain. This was a cohort analysis of treatment outcomes pre- and postmicrocurrent stimulation, involving 34 patients with a history of nonspecific chronic neck pain. Consenting patients were enrolled from a group of therapists attending educational seminars and were asked to report pain levels pre-post and 48 hours after a single MPS application. Direct current microcurrent point stimulation (MPS) applied to standardized lower back acupuncture protocol points was used. Evaluations entailed a baseline visual analog scale (VAS) pain scale assessment, using a VAS, which was repeated twice after therapy, once immediately postelectrotherapy and again after a 48-h follow-up period. All 34 patients received a single MPS session. Results were analyzed using paired t tests. Results and Outcomes: Pain intensity showed an initial statistically significant reduction of 68% [3.9050 points; 95% CI (2.9480, 3.9050); p = 0.0001], in mean neck pain levels after standard protocol treatment, when compared to initial pain levels. There was a further statistically significant reduction of 35% in mean neck pain levels at 48 h when compared to pain levels immediately after standard protocol treatment [0.5588 points; 95% CI (0.2001, 0.9176); p = 0.03], for a total average pain relief of 80%. The positive results in this study could have applications for those patients impacted by chronic neck pain.

Er:YAG Laser Versus Cold Knife Excision in the Treatment of Nondysplastic Oral Lesions: A Randomized Comparative Study for the Postoperative Period.

PubMed

Broccoletti, Roberto; Cafaro, Adriana; Gambino, Alessio; Romagnoli, Ercole; Arduino, Paolo Giacomo

2015-12-01

The aim of this prospective study was to estimate the effects of Erbium substituted: Yttrium Aluminium Garnet (Er:YAG) laser, compared with traditional scalpel, on the early postoperative sequelae of nondysplastic oral lesion removal. There is limited evidence that laser surgery could exhibit advantages over scalpel in oral mucosal surgery. The investigators studied a cohort of 344 patients; 394 lesions were randomized and treated. Outcome statistically evaluated variables were: age, gender, the site and size of investigated lesions, visual analogue score (VAS) of pain, the Oral Health Impact Profile questionnaire (OHIP-14) and the Quality of Life test (QOL), and number of analgesics taken in the 1st week after surgery. Significant differences were found if considering the surgical time, VAS, and QOL and OHIP-14 questionnaires; regarding those data, the Er:YAG laser appeared to be faster and less painful than traditional scalpel (p < 0.05). For bigger lesions, patients statistically took more painkillers if they had undergone traditional surgery. Considering the site of the treated lesions, Er:YAG laser was less painful, especially in the gingiva and palate (p < 0.05). This is the first randomized controlled surgical trial reported for the management of nondysplastic oral lesions with the use of an Er:YAG laser. With many limitations, the present report identifies significant difference in the immediate postoperative surgical period between the two treatments, meaning that the Er:YAG laser seemed to be less painful, and better accepted by patients, than traditional scalpel.

Spinal cord stimulation for treatment of meralgia paresthetica.

PubMed

Barna, Steven A; Hu, M Melvin; Buxo, Carlos; Trella, Jason; Cosgrove, G Rees

2005-07-01

Meralgia paresthetica is a clinical syndrome of pain, dysesthesia or both, in the anterolateral thigh. It is associated with an entrapment mononeuropathy of the lateral femoral cutaneous nerve. Diagnosis of meralgia paresthetica is typically made clinically and is based on the characteristic location of pain or dysesthesia, sensory abnormality on exam, and absence of any other neurological abnormality in the leg. The majority of patients with meralgia paresthetica respond well to conservative treatment. To present a case of intractable meralgia paresthetica in which conservative treatment options failed but which was successfully treated with a spinal cord stimulator. A 44-year-old woman presented to the pain clinic with a one-year history of bilateral anterolateral thigh pain. History, physical exam, and diagnostic work-up were consistent with meralgia paresthetica. Multiple medications, physical therapy, and chiropractic therapy were not successful for this patient. In addition, local anesthetic/steroid injection of the lateral femoral cutaneous nerve provided only short-term relief. Ultimately, a spinal cord stimulator was implanted after a successful temporary percutaneous trial. Two months after the implantation, she continued to have 100% pain relief, worked full-time, was physically active, and no longer required any pain medication including opioids. An implanted spinal cord stimulator may be an ideal treatment for intractable meralgia paresthetica after conservative treatments have failed because it is not destructive and can always be explanted without significant permanent adverse effects.

Reproduction of overall spontaneous pain pattern by manual stimulation of active myofascial trigger points in fibromyalgia patients

PubMed Central

2011-01-01

Introduction It has previously been reported that local and referred pain from active myofascial trigger points (MTPs) in the neck and shoulder region contribute to fibromyalgia (FM) pain and that the pain pattern induced from active MTPs can reproduce parts of the spontaneous clinical FM pain pattern. The current study investigated whether the overall spontaneous FM pain pattern can be reproduced by local and referred pain from active MTPs located in different muscles. Methods A spontaneous pain pattern in FM was recorded in 30 FM patients and 30 healthy subjects served as controls. Local and referred pain patterns induced from active (patients) and latent (controls) MTPs were recorded following manual stimulation. The existence of MTPs was confirmed by intramuscular electromyographical registration of spontaneous electrical activity. Results Local and referred pain areas induced from key active MTPs in FM were larger than pain areas from latent MTPs in healthy controls (P < 0.001), but were similar to the overall spontaneous FM pain area in FM (P > 0.05). The induced pain area was positively associated with current spontaneous pain intensity in FM (P < 0.01). The locations of key active MTPs in FM patients were found to have latent MTPs in healthy subjects. The muscles containing key active MTPs in FM are often observed in the muscles of extensor digitorum, trapezius, infraspinatus in the upper part of the body and of quadratus lumborum, gluteus medius in the lower part of the body. Conclusions The overall spontaneous FM pain pattern can be reproduced by mechanical stimulation of active MTPs located in different muscles, suggesting that fibromyalgia pain is largely composed of pain arising from muscle pain and spasm. Targeting active MTPs and related perpetuating factors may be an important strategy in FM pain control. Trial registration ISRCTN ISRCTN43167547. PMID:21426569

Feasibility study of Transcutaneous Electrical Nerve Stimulation (TENS) for cancer bone pain.

PubMed

Bennett, Michael I; Johnson, Mark I; Brown, Sarah R; Radford, Helen; Brown, Julia M; Searle, Robert D

2010-04-01

This multicenter study assessed the feasibility of conducting a phase III trial of transcutaneous electrical nerve stimulation (TENS) in patients with cancer bone pain recruited from palliative care services. Eligible patients received active and placebo TENS for 1 hour at site of pain in a randomized crossover design; median interval between applications 3 days. Responses assessed at 30 and 60 minutes included numerical and verbal ratings of pain at rest and on movement, and pain relief. Recruitment, tolerability, adverse events, and effectiveness of blinding were also evaluated. Twenty-four patients were randomised and 19 completed both applications. The intervention was well tolerated. Five patients withdrew: 3 due to deteriorating performance status, and 2 due to increased pain (1 each following active and placebo TENS). Confidence interval estimation around the differences in outcomes between active and placebo TENS suggests that TENS has the potential to decrease pain on movement more than pain on rest. Nine patients did not consider that a placebo was used; the remaining 10 correctly identified placebo TENS. Feasibility studies are important in palliative care prior to undertaking clinical trials. Our findings suggest that further work is required on recruitment strategies and refining the control arm before evaluating TENS in cancer bone pain. Cancer bone pain is common and severe, and partly mediated by hyperexcitability. Animal studies suggest that Transcutaneous Electrical Nerve Stimulation can reduce hyperalgesia. This study examined the feasibility of evaluating TENS in patients with cancer bone pain in order to optimize methods before a phase III trial. Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.

Can Ashi points stimulation have specific effects on shoulder pain? A systematic review of randomized controlled trials.

PubMed

Wang, Kang-Feng; Zhang, Li-Juan; Lu, Feng; Lu, Yong-Hui; Yang, Chuan-Hua

2016-06-01

To provide an evidence-based overview regarding the efficacy of Ashi points stimulation for the treatment of shoulder pain. A comprehensive search [PubMed, Chinese Biomedical Literature Database, China National Knowledge Infrastructure (CNKI), Chongqing Weipu Database for Chinese Technical Periodicals (VIP) and Wanfang Database] was conducted to identify randomized or quasi-randomized controlled trials that evaluated the effectiveness of Ashi points stimulation for shoulder pain compared with conventional treatment. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. RevMan 5.0 was used for data synthesis. Nine trials were included. Seven studies assessed the effectiveness of Ashi points stimulation on response rate compared with conventional acupuncture. Their results suggested significant effect in favour of Ashi points stimulation [odds ratio (OR): 5.89, 95% confidence interval (CI): 2.97 to 11.67, P<0.01, heterogeneity: χ(2) =3.81, P=0.70, I (2) =0% ]. One trial compared Ashi points stimulation with drug therapy. The result showed there was a significantly greater recovery rate in group of Ashi points stimulation (OR: 9.58, 95% CI: 2.69 to 34.12). One trial compared comprehensive treatment on the myofascial trigger points (MTrPs) with no treatment and the result was in favor of MTrPs. Ashi points stimulation might be superior to conventional acupuncture, drug therapy and no treatment for shoulder pain. However, due to the low methodological quality of included studies, a firm conclusion could not be reached until further studies of high quality are available.

The effects of elevated pain inhibition on endurance exercise performance.

PubMed

Flood, Andrew; Waddington, Gordon; Keegan, Richard J; Thompson, Kevin G; Cathcart, Stuart

2017-01-01

The ergogenic effects of analgesic substances suggest that pain perception is an important regulator of work-rate during fatiguing exercise. Recent research has shown that endogenous inhibitory responses, which act to attenuate nociceptive input and reduce perceived pain, can be increased following transcranial direct current stimulation of the hand motor cortex. Using high-definition transcranial direct current stimulation (HD-tDCS; 2 mA, 20 min), the current study aimed to examine the effects of elevated pain inhibitory capacity on endurance exercise performance. It was hypothesised that HD-tDCS would enhance the efficiency of the endogenous pain inhibitory response and improve endurance exercise performance. Twelve healthy males between 18 and 40 years of age ( M  = 24.42 ± 3.85) were recruited for participation. Endogenous pain inhibitory capacity and exercise performance were assessed before and after both active and sham (placebo) stimulation. The conditioned pain modulation protocol was used for the measurement of pain inhibition. Exercise performance assessment consisted of both maximal voluntary contraction (MVC) and submaximal muscular endurance performance trials using isometric contractions of the non-dominant leg extensors. Active HD-tDCS (pre-tDCS, -.32 ± 1.33 kg; post-tDCS, -1.23 ± 1.21 kg) significantly increased pain inhibitory responses relative to the effects of sham HD-tDCS (pre-tDCS, -.91 ± .92 kg; post-tDCS, -.26 ± .92 kg; p  = .046). Irrespective of condition, peak MVC force and muscular endurance was reduced from pre- to post-stimulation. HD-tDCS did not significantly influence this reduction in maximal force (active: pre-tDCS, 264.89 ± 66.87 Nm; post-tDCS, 236.33 ± 66.51 Nm; sham: pre-tDCS, 249.25 ± 88.56 Nm; post-tDCS, 239.63 ± 67.53 Nm) or muscular endurance (active: pre-tDCS, 104.65 ± 42.36 s; post-tDCS, 93.07 ± 33.73 s; sham: pre-tDCS, 123.42 ± 72.48 s; post-tDCS, 100.27 ± 44.25 s). Despite increasing pain inhibitory capacity relative to sham stimulation, active HD-tDCS did not significantly elevate maximal force production or muscular endurance. These findings question the role of endogenous pain inhibitory networks in the regulation of exercise performance.

[Comparison of the effect of laser and magnetic therapy for pain level and the range of motion of the spine of people with osteoarthritis lower back].

PubMed

Zdrodowska, Beata; Leszczyńska-Filus, Magdalena; Leszczyński, Ryszard; Błaszczyk, Jan

2015-01-01

Increased expression of degenerative disease of the lumbar spine is an onerous task, which reduces the efficiency of the activity and life of many populations. It is the most common cause of medical visits. In 95% of cases the cause of complaints is a destructive process in the course of degenerative intervertebral disc called a lumbar disc herniation. Protrusion of the nucleus pulposus causes severe pain and impaired muscle tone, often more chronic and difficult to master. Successful treatment of lumbar disc herniation constitutes a serious interdisciplinary problem. It is important to properly planned and carried out physiotherapy. Based on the number of non-invasive methods, to reduce muscle tension, mute pain and alleviation of inflammation. It is the treatment safe, effective, and at the same time, which is their big advantage, readily available and cheap. It is worth noting that not every method has the same efficiency. The question that the methods are effective in relieving pain and helping to effectively increase the range of motion led to a comparison of two methods - Low Level Laser Therapy (LLLT) and pulsating magnetic field therapy. The aim of the study was to compare the efficacy of LLLT and pulsating magnetic field therapy in combating pain and increase range of motion of the spine of people with degenerative spine disease of the lower back. 120 patients with diagnose lumbar disc herniation whit no nerve roots symptoms. Patients were divided into two Groups: A and B. Group A of 60 patients were subjected to laser therapy (λ=820nm, P=400mW, Ed=6-12 J/cm²) and the second Group B of 60 patients too, to pulsating magnetic fields procedures (5mT, 30 Hz, 15 minutes). Every patient before rehabilitation started and right after it has finished has undergone examination. Subjective pain assessment was carried out using a modified Laitinen questionnaire and Visual Analogue Scale of Pain intensity. Spine mobility was evaluated whit the Schober test and the Fingertip-to-floor-test. The obtained results were subjects to statistical analysis. Research shows that both low energy laser and pulsating magnetic field physical attributes are effective methods for the treatment of pain and restricted mobility of the spine caused by disc herniation. Careful analysis emphasizes greater efficiency laser for pain. In contrast, a statistically greater improvement in global mobility of the spine, as well as flexion and extension of the lumbar recorded in group B, where the applied pulsating magnetic field. Both laser and magnet therapy reduces pain and improves mobility of the spine of people with degenerative spine disease of the lower back. Comparison of the effectiveness of both methods showed a greater analgesic effect of laser treatment, and greater mobility of the spine was observed under the influence of pulsating magnetic field therapy. © 2015 MEDPRESS.

Intensity Modulation: A Novel Approach to Percept Control in Spinal Cord Stimulation.

PubMed

Tan, Daniel; Tyler, Dustin; Sweet, Jennifer; Miller, Jonathan

2016-04-01

Spinal cord stimulation (SCS) can be effective for neuropathic pain, but clinical benefit is sometimes inadequate or is offset by stimulation-induced side-effects, and response can be inconsistent among patients. Intensity-modulated stimulation (IMS) is an alternative to tonic stimulation (TS) that involves continuous variation of stimulation intensity in a sinusoidal pattern between two different values, sequentially activating distinct axonal populations to produce an effect that resembles natural physiological signals. The purpose of this study is to evaluate the effect of IMS on the clinical effect of SCS. Seven patients undergoing a percutaneous SCS trial for postlaminectomy syndrome were enrolled. Thresholds for perception, pain relief, and discomfort were measured and used to create patient-specific models of axonal activation and charge delivery for both TS and IMS. All participants underwent three two-min periods of blinded stimulation using TS, IMS, and placebo, and were asked to describe the effect on quality of the sensory percept and pain relief. All participants perceived IMS differently from placebo, and five noted significant differences from TS that resulted in a more comfortable sensation. TS was described as electric and tingling, whereas IMS was described as producing a focal area of deep pressure with a sense of motion away from that focus. The anatomic location of coverage was similar between the two forms of stimulation, although one participant reported better lower back coverage with IMS. Computer modeling revealed that, compared with TS, IMS involved 36.4% less charge delivery and produced 78.7% less suprathreshold axonal activation. IMS for SCS is feasible, produces a more comfortable percept than conventional TS, and appears to provide a similar degree of pain relief with significantly lower energy requirements. Further studies are necessary to determine whether this represents an effective alternative to tonic SCS for treatment of neuropathic pain. © 2015 International Neuromodulation Society.

Mechanical Strains Induced in Osteoblasts by Use of Point Femtosecond Laser Targeting

PubMed Central

Bomzon, Ze'ev; Day, Daniel; Gu, Min; Cartmell, Sarah

2006-01-01

A study demonstrating how ultrafast laser radiation stimulates osteoblasts is presented. The study employed a custom made optical system that allowed for simultaneous confocal cell imaging and targeted femtosecond pulse laser irradiation. When femtosecond laser light was focused onto a single cell, a rise in intracellular Ca2+ levels was observed followed by contraction of the targeted cell. This contraction caused deformation of neighbouring cells leading to a heterogeneous strain field throughout the monolayer. Quantification of the strain fields in the monolayer using digital image correlation revealed local strains much higher than threshold values typically reported to stimulate extracellular bone matrix production in vitro. This use of point targeting with femtosecond pulse lasers could provide a new method for stimulating cell activity in orthopaedic tissue engineering. PMID:23165014

Effects of spinal cord stimulation in angina pectoris induced by pacing and possible mechanisms of action.

PubMed Central

Mannheimer, C; Eliasson, T; Andersson, B; Bergh, C H; Augustinsson, L E; Emanuelsson, H; Waagstein, F

1993-01-01

OBJECTIVE--To investigate the effects of spinal cord stimulation on myocardial ischaemia, coronary blood flow, and myocardial oxygen consumption in angina pectoris induced by atrial pacing. DESIGN--The heart was paced to angina during a control phase and treatment with spinal cord stimulation. Blood samples were drawn from a peripheral artery and the coronary sinus. SETTING--Multidisciplinary pain centre, department of medicine, Ostra Hospital, and Wallenberg Research Laboratory, Sahlgrenska Hospital, Gothenburg, Sweden. SUBJECTS--Twenty patients with intractable angina pectoris, all with a spinal cord stimulator implanted before the study. RESULTS--Spinal cord stimulation increased patients' tolerance to pacing (p < 0.001). At the pacing rate comparable to that producing angina during the control recording, myocardial lactate production during control session turned into extraction (p = 0.003) and, on the electrocardiogram, ST segment depression decreased, time to ST depression increased, and time to recovery from ST depression decreased (p = 0.01; p < 0.05, and p < 0.05, respectively). Spinal cord stimulation also reduced coronary sinus blood flow (p = 0.01) and myocardial oxygen consumption (p = 0.02). At the maximum pacing rate during treatment, all patients experienced anginal pain. Myocardial lactate extraction reverted to production (p < 0.01) and the magnitude and duration of ST segment depression increased to the same values as during control pacing, indicating that myocardial ischaemia during treatment with spinal cord stimulation gives rise to anginal pain. CONCLUSIONS--Spinal cord stimulation has an anti-anginal and anti-ischaemic effect in severe coronary artery disease. These effects seem to be secondary to a decrease in myocardial oxygen consumption. Furthermore, myocardial ischemia during treatment gives rise to anginal pain. Thus, spinal cord stimulation does not deprive the patient of a warning signal. PMID:8400930

Immediate effects of microsystem acupuncture in patients with oromyofacial pain and craniomandibular disorders (CMD): a double-blind, placebo-controlled trial.

PubMed

Simma, I; Gleditsch, J M; Simma, L; Piehslinger, E

2009-12-19

Patients presenting with oromyofacial disorders and pain in the head and neck area are often resistant to conventional therapy. Acupuncture has been shown to be effective in pain reduction. Twenty-three patients with craniomandibular disorders, headache and, in particular, local pain in the orofacial, cervical and temporomandibular joint areas were randomised into acupuncture or placebo laser therapy groups. Pain was assessed by a visual analogue scale (VAS) and by palpation of 14 muscles and groups of muscles immediately before and after treatment, the assessor being blinded to the patients' allocation. Applicable acupuncture points were searched and pricked using the 'very-point' technique. Pain reduction measured by VAS was significantly more pronounced after acupuncture than after placebo treatment (p=0.031). Sum of pain scores across 14 muscles was considerably more reduced after acupuncture as compared to sham laser treatment. Acupuncture may bring about immediate pain relief in patients with oromyofacial disorders, increasing the chance to initiate other therapeutic measures.

Physiological correlates of imagery-induced orgasm in women.

PubMed

Whipple, B; Ogden, G; Komisaruk, B R

1992-04-01

Orgasm has been reported to occur in response to imagery in the absence of any physical stimulation. This study was undertaken to ascertain whether the subjective report of imagery-induced orgasm is accompanied by physiological and perceptual events that are characteristic of genitally stimulated orgasm. Subjects were women who claimed that they could experience orgasm from imagery alone. Orgasm from self-induced imagery or genital self-stimulation generated significant increases in systolic blood pressure, heart rate, pupil diameter, pain detection threshold, and pain tolerance threshold over resting control conditions. These findings provide evidence that orgasm from self-induced imagery and genital self-stimulation can each produce significant and substantial net sympathetic activation and concomitant significant increases in pain thresholds. The increases in the self-induced imagery orgasm condition were comparable in magnitude to those in the genital self-stimulation-produced orgasm condition. On this basis we state that physical genital stimulation is evidently not necessary to produce a state that is reported to be an orgasm and that a reassessment of the nature of orgasm is warranted.

An algorithmic programming approach for back pain symptoms in failed back surgery syndrome using spinal cord stimulation with a multicolumn surgically implanted epidural lead: a multicenter international prospective study.

PubMed

Rigoard, Philippe; Jacques, Line; Delmotte, Alexandre; Poon, Katherine; Munson, Russell; Monlezun, Olivier; Roulaud, Manuel; Prevost, Audrey; Guetarni, Farid; Bataille, Benoit; Kumar, Krishna

2015-03-01

Many studies have demonstrated the efficacy and the medical/economic value of epidural spinal cord stimulation for the treatment of "failed back surgery syndrome" (FBSS). However, the back pain component of FBSS has been recalcitrant. Recent clinical trials have suggested that multicolumn surgically implanted leads combined with enhanced programming capabilities in the newer implantable pulse generators demonstrate the ability to treat the back pain component of FBSS. The objective of our present international multicentre study is to prospectively evaluate these findings in a larger population. We conducted a prospective, nonrandomized, observational study on 76 patients with refractory FBSS, consecutively implanted with multicolumn spinal cord stimulation (SCS) between 2008 and 2011 in three neurosurgical pain management centers (Poitiers, France; Montréal, Canada; and Regina, Canada). The primary objective of this study was to prospectively analyze the effect of multicolumn lead programming on paresthesia coverage for the back pain region in these patients. The secondary objective was to assess the analgesic efficacy of this technique on the global and back pain components. Paresthesia could be induced in the lower extremities in the majority of patients with at least one of the configurations tested. Bilateral low back paresthesia was induced in 53.5% of patients, while unilateral low back paresthesia was induced in 78.9% of patients. Multicolumn configurations were statistically more effective than monocolumn configurations for all anatomic regions studied. At 6 months, 75.4% of patients receiving multicolumn stimulation (n = 57) obtained at least a 30% improvement of the back pain VAS score, while 42.1% of patients obtained at least a 50% improvement of the back pain VAS score. This study confirms the hypothesis that multicolumn SCS should be considered as an important tool in the treatment of radicular and axial pain in FBSS patients. The efficacy of this modality is based on a rigorous patient selection process, access to new generation lead technologies, but most importantly an algorithmic programming approach for optimal stimulation and electrical field shaping. With over 40 million potential programming combinations associated with 16 contact leads to achieve paresthesia coverage, optimal stimulation is often missed as either the patient or the clinician become exhausted or overwhelmed during the course of therapy programming and optimization session. © 2014 World Institute of Pain.

Thermographic and clinical evaluation of 808-nm laser photobiomodulation effects after third molar extraction.

PubMed

Pedreira, Amanda A; Wanderley, Flavia G; Sa, Maira F; Viena, Camila S; Perez, Adriano; Hoshi, Ryuichi; Leite, Marcia P; Reis, Silvia R; Medrado, Alena P

2016-08-01

A randomized, blind, controlled clinical study was conducted with a convenience sample of 24 patients to evaluate the effectiveness of an aluminum gallium arsenide (AlGaAs) infrared laser 808 nm after third molar extraction by the use of infrared thermography technique. Patients were divided into four groups: erupted third molars were extracted from the patients in Group I and Group II, and impacted third molars were extracted from the patients in Group III and Group IV. Group I and Group III received mock laser therapy in which the device was powered off, and Group II and Group IV were exposed to laser light. Postoperative clinical parameters related to the third molar extraction were evaluated; these parameters included pain, trismus and edema. Circulatory patterns were also evaluated by infrared thermography that exhibited local temperature coefficient at different postoperative periods. A slight improvement was observed for swelling, pain and trismus in patients who received laser irradiation, although the differences were not statistically significant (P>0.05). Laser therapy had a significant influence on the local circulation in the area near the temporomandibular joint, as determined by infrared thermography (P<0.05). Laser therapy was able to change the local circulation, although it did not significantly influence swelling, pain or trismus during the postoperative period.

Haemodynamic responses in chronically painful, human trapezius muscle to cold pressor stimulation.

PubMed

Acero, C O; Kuboki, T; Maekawa, K; Yamashita, A; Clark, G T

1999-10-01

The aim was to compare haemodynamic responses in trapezius muscles to cold pressor stimulation in individuals with localized trapezius myalgia and asymptomatic controls. Nine males with chronic localized pain in the trapezius (mean age, 23.2 years) and nine male controls (mean age, 24.6 years) who had no medical history of migraine, hypertension or sustained pain in the trapezius region were investigated. Two experimental (cold pressor and mock) trials were performed in a randomly assigned sequence. In the cold pressor trial the participant's left foot and ankle were immersed in 4 degrees C cold water for 2 min; the mock trial was done without that stimulus. Blood volume was continuously recorded 1 min before, 2 min during, and 5 min after cold pressor stimulation using near-infrared spectroscopy. Each participant's blood-volume data were baseline-corrected and submitted to statistical analysis. Results showed that the individuals with muscle pain exhibited a significantly lower mean blood volume than the controls during cold pressor stimulation (p = 0.0367). Upon withdrawal of that stimulation, the mean blood volume in both groups fell below the baseline. These results suggest that individuals with chronic regional trapezius myalgia have less capacity to vasodilate this muscle during cold pressor stimulation than those without such myalgia. It is not yet known if this difference in the haemodynamic response is a cause or an effect of the myalgia.

Improved Walking Claudication Distance with Transcutaneous Electrical Nerve Stimulation: An Old Treatment with a New Indication in Patients with Peripheral Artery Disease.

PubMed

Labrunée, Marc; Boned, Anne; Granger, Richard; Bousquet, Marc; Jordan, Christian; Richard, Lisa; Garrigues, Damien; Gremeaux, Vincent; Sénard, Jean-Michel; Pathak, Atul; Guiraud, Thibaut

2015-11-01

The aim of this study was to determine whether 45 mins of transcutaneous electrical nerve stimulation before exercise could delay pain onset and increase walking distance in peripheral artery disease patients. After a baseline assessment of the walking velocity that led to pain after 300 m, 15 peripheral artery disease patients underwent four exercise sessions in a random order. The patients had a 45-min transcutaneous electrical nerve stimulation session with different experimental conditions: 80 Hz, 10 Hz, sham (presence of electrodes without stimulation), or control with no electrodes, immediately followed by five walking bouts on a treadmill until pain occurred. The patients were allowed to rest for 10 mins between each bout and had no feedback concerning the walking distance achieved. Total walking distance was significantly different between T10, T80, sham, and control (P < 0.0003). No difference was observed between T10 and T80, but T10 was different from sham and control. Sham, T10, and T80 were all different from control (P < 0.001). There was no difference between each condition for heart rate and blood pressure. Transcutaneous electrical nerve stimulation immediately before walking can delay pain onset and increase walking distance in patients with class II peripheral artery disease, with transcutaneous electrical nerve stimulation of 10 Hz being the most effective.

Pain and psycho-affective disorders.

PubMed

Broggi, Giovanni

2008-06-01

The subject of human pain can be subdivided into two broad categories: physical pain and psychological pain. Since the dawn of human consciousness, each of these two forms of pain-one clearly physical, the other having more to deal with the mind-have played a central role in human existence. Psychological pain and suffering add dimensions that go far beyond the boundaries of its physical counterpart. In the past 50 years, one of the more remarkable accomplishments of medical science has been to increasingly enable the clinician to impact, as never before, each of these critical realms of human existence. Our intention is, therefore, to initially describe a few of the many exciting neuroscientific and neurosurgical advances that have been made in the treatment of various types of pain and to speculate on some of the emergent questions that we believe need to be addressed. After this is accomplished, we will then use this information as a kind of two-pronged philosophical entrance into questions of the mind, brain, and soul that we feel are necessary to bring back into the sphere of the modern physician's practice. The goal of this article is two-fold: 1) to share some of our exciting research and 2) to renew the interest in timeless questions, such as that of the mind-brain and the brain-mind, in the conversation of the modern neurosurgeon. The International Association for the Study of Pain divides pain into two broad functions and anatomical categories. In this framework, "nociceptive" pain is defined as the kind of physical pain that results when the tissue is damaged. Given this perspective, such pain is usually considered a consequence of one's defense against one's environment. The other pain is the "neuropathic" one resulting from a lesion or a dysfunction of the human nervous system. As such, we will take the risk of crossing beyond the boundaries of neurosurgery and venture into boundaries that, at another time, might seem more natural to the discipline of psychiatry for two reasons. The first is that psychiatry seems to be so focused on the brain-its biochemistry and pharmacology--that questions of mind and soul have become rare and almost negligible. The second is to follow the course of the results of our own clinical investigations that have taken us into that very human world where questions of physical pain, psychological pain, and the experience of suffering abound. Today, however, the strategy of neuromodulation offers the advantage of being precisely tailored in neuroanatomical terms and, even more importantly, of being altogether reversible. At both our own Istituto Neurologico C. Besta and many other neurosurgical centers worldwide, many procedures have been reported in which implant neuromodulation devices successfully treat pain. For example, long-term stimulation of the spinal cord has been fairly effective in the treatment of neuropathic pain, multiple sclerosis, and various other forms of pain. Good results have been obtained in treating peripheral vascular diseases and sympathetic reflex dystrophy syndrome. Good results have also been achieved in trigeminal nerve stimulation and peripheral nerve stimulation. In the case of thalamic stimulation, there has also been an improvement of symptoms, but a long-term degree of tolerance was noticed. Hypothalamic stimulation has also been seen to be effective in controlling trigeminal autonomic cephalalgic pain, as well as the facial pain that is known to occur in multiple sclerosis. Motor cortex stimulation was found to occasionally have good results in treating neuropathic pain, whereas occipital nerve stimulation was found to achieve good results in controlling chronic cluster headache and other chronic headaches, although with only short-term follow-up so far. Recent reports of functional magnetic resonance imaging have prompted us to propose exciting new neurosurgical targets that may be effective in treating psychoaffective disorders. Our results appear to be more than promising so far. It appears that neuropathic pain and psychoaffective disorders seem to be sharing an anatomophysiological common background at the Brodmann Area 25 of the anterior cingulated gyrus. On the basis of these exciting findings, we believe that it is reasonable to suggest that neuropathic pain and psychoaffective disorders may ultimately be managed with complementary or, at least, similar, therapeutic strategies, each of which lie within the domain of the neurosurgeon.

The “at-home LLLT” in temporo-mandibular disorders pain control: a pilot study

PubMed Central

Pelosi, A; Queirolo, V; Vescovi, P; Merigo, E

2015-01-01

Objectives: The Temporo-Mandibular Disorders (TMD) are a set of dysfunctional patterns concerning the temporo-mandibular joints (TMJ) and the masticatory muscles; its main symptom is pain, probably caused by inflammatory changes in the synovial membrane, alterations in the bone marrow of the mandibular condyle and impingement and compression. The aim of this preliminary study was to investigate the effectiveness in the TMD pain reduction of a new laser device recently proposed by the commerce that, due to its reduced dimensions and to be a class I laser according the ANSI classification, may be used at home by the patient himself. Material and methods: Twenty-four patients with TMD were randomly selected: the inclusion criteria for the sample was the diagnosis of mono- or bi-lateral TMD, with acute pain restricted to the joint area, associated with the absence of any muscle tenderness during palpation. The patients were randomly assigned to two groups: Group 1 (12 patients): patients receiving real LLLT (experimental group). Group 2 (12 patients): patients receiving inactive laser (placebo group). The treatment was performed once a day for two weeks with an 808 nm diode laser by the patient himself with irradiation of the cutaneous zone corresponding to the TMJ for 15 minutes each side. Each patient was instructed to express its pain in a visual analogue scale (VAS) making a perpendicular line between the two extremes representing the felt pain level. Statistical analysis was realized with GraphPad Instat Software, where P<0.05 was considered significant and P<0.01 very significant. Results: The patient's pain evaluation was expressed in the two study groups before the treatment, 1 week and two weeks after the treatment. The differences between the two groups result extremely significant with p<0.0001 for the comparison of VAS value after 1 and 2 weeks. Conclusion: This study, even if it may be considered such a pilot study, investigated a new way to control the pain in the temporo-mandibular diseases by an at home self administered laser device. Results are encouraging but they will have to be confirmed by greater studies. PMID:25941425

The "at-home LLLT" in temporo-mandibular disorders pain control: a pilot study.

PubMed

Fornaini, C; Pelosi, A; Queirolo, V; Vescovi, P; Merigo, E

2015-03-31

The Temporo-Mandibular Disorders (TMD) are a set of dysfunctional patterns concerning the temporo-mandibular joints (TMJ) and the masticatory muscles; its main symptom is pain, probably caused by inflammatory changes in the synovial membrane, alterations in the bone marrow of the mandibular condyle and impingement and compression. The aim of this preliminary study was to investigate the effectiveness in the TMD pain reduction of a new laser device recently proposed by the commerce that, due to its reduced dimensions and to be a class I laser according the ANSI classification, may be used at home by the patient himself. Twenty-four patients with TMD were randomly selected: the inclusion criteria for the sample was the diagnosis of mono- or bi-lateral TMD, with acute pain restricted to the joint area, associated with the absence of any muscle tenderness during palpation. The patients were randomly assigned to two groups: Group 1 (12 patients): patients receiving real LLLT (experimental group). Group 2 (12 patients): patients receiving inactive laser (placebo group). The treatment was performed once a day for two weeks with an 808 nm diode laser by the patient himself with irradiation of the cutaneous zone corresponding to the TMJ for 15 minutes each side. Each patient was instructed to express its pain in a visual analogue scale (VAS) making a perpendicular line between the two extremes representing the felt pain level. Statistical analysis was realized with GraphPad Instat Software, where P<0.05 was considered significant and P<0.01 very significant. The patient's pain evaluation was expressed in the two study groups before the treatment, 1 week and two weeks after the treatment. The differences between the two groups result extremely significant with p<0.0001 for the comparison of VAS value after 1 and 2 weeks. This study, even if it may be considered such a pilot study, investigated a new way to control the pain in the temporo-mandibular diseases by an at home self administered laser device. RESULTS are encouraging but they will have to be confirmed by greater studies.

Temperature dependence of quasi-three level laser transition for long pulse Nd:YAG laser

NASA Astrophysics Data System (ADS)

Bidin, Noriah; Pourmand, Seyed Ebrahim; Sidi Ahmad, Muhamad Fakaruddin; Khrisnan, Ganesan; Mohd Taib, Nur Athirah; Nadia Adnan, Nurul; Bakhtiar, Hazri

2013-02-01

The influence of temperature and pumping energy on stimulated emission cross section and the laser output of quasi-three level laser transition are reported. Flashlamp is used to pump Nd:YAG laser rod. Distilled water is mixed with ethylene glycol to vary the temperature of the cooling system between -30 and 60 °C. The capacitor voltage of flashlamp driver is verified to manipulate the input energy within the range of 10-70 J. The line of interest in quasi-three level laser comprised of 938.5 and 946 nm. The stimulated emission cross section of both lines is found to be inversely proportional to the temperature but directly proportional to the input energy. This is attributed from thermal broadening effect. The changes of stimulated emission cross section and the output laser with respect to the temperature and input energy on line 946 nm are realized to be more dominant in comparison to 938.5 nm.

Anesthesia Methods in Laser Resurfacing

PubMed Central

Gaitan, Sergio; Markus, Ramsey

2012-01-01

Laser resurfacing technology offers the ability to treat skin changes that are the result of the aging process. One of the major drawbacks of laser resurfacing technologies is the pain associated with the procedure. The methods of anesthesia used in laser resurfacing to help minimize the pain include both noninvasive and invasive procedures. The noninvasive procedures can be divided into topical, cryoanesthesia, and a combination of both. The invasive methods of anesthesia include injected forms (infiltrative, nerve blocks, and tumescent anesthesia) and supervised anesthesia (monitored anesthesia care and general anesthesia). In this review, the authors summarize the types of anesthesia used in laser resurfacing to aid the provider in offering the most appropriate method for the patient to have as painless a procedure as possible. PMID:23904819

Safety and efficacy of low fluence, high repetition rate versus high fluence, low repetition rate 810-nm diode laser for axillary hair removal in Chinese women.

PubMed

Li, Wenhai; Liu, Chengyi; Chen, Zhou; Cai, Lin; Zhou, Cheng; Xu, Qianxi; Li, Houmin; Zhang, Jianzhong

2016-11-01

High-fluence diode lasers with contact cooling have emerged as the gold standard to remove unwanted hair. Lowering the energy should result in less pain and could theoretically affect the efficacy of the therapy. To compare the safety and efficacy of a low fluence high repetition rate 810-nm diode laser to those of a high fluence, low repetition rate diode laser for permanent axillary hair removal in Chinese women. Ninety-two Chinese women received four axillae laser hair removal treatments at 4-week intervals using the low fluence, high repetition rate 810-nm diode laser in super hair removal (SHR) mode on one side and the high fluence, low repetition rate diode laser in hair removal (HR) mode on the other side. Hair counts were done at each follow-up visit and 6-month follow-up after the final laser treatment using a "Hi Quality Hair Analysis Program System"; the immediate pain score after each treatment session was recorded by a visual analog scale. The overall median reduction of hair was 90.2% with the 810-nm diode laser in SHR mode and 87% with the same laser in HR mode at 6-month follow-up. The median pain scores in SHR mode and in HR mode were 2.75 and 6.75, respectively. Low fluence, high repetition rate diode laser can efficiently remove unwanted hair but also significantly improve tolerability and reduce adverse events during the course of treatment.

The water avoidance stress induces bladder pain due to a prolonged alpha1A adrenoceptor stimulation.

PubMed

Matos, Rita; Serrão, Paula; Rodriguez, Larissa; Birder, Lori Ann; Cruz, Francisco; Charrua, Ana

2017-08-01

Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) remains an elusive disease with the cause for the pain unclear. BPS/IC patients present increased sympathetic activity and high levels of urinary noradrenaline. At the experimental level, it has been shown that chronic adrenergic stimulation produces pain and bladder changes through an alpha 1A adrenoceptor mediated mechanism. Water avoidance stress (WAS) in rodents reproduces signs of nociception and bladder changes seen in BPS/IC patients. In this study, we explore the possible role of alpha 1A adrenoceptor in bladder pain and morphological changes. WAS was induced in a group of female Wistar rats. A separate WAS group received 0.2 mg/kg day silodosin (WAS + S). Lower abdominal pain was determined by performing sensitivity to Von Frey filaments. Bladder reflex activity was determined by cystometry in anaesthetised animals. Urine was collected for noradrenaline quantification by HPLC. Bladders were harvested and stained with Haematoxylin-eosin (to analyse urothelial morphology and to determine the disruption of surface umbrella cells) or with Toluidine Blue 0.1% to analyse mast cell infiltration. WAS increased urinary noradrenaline level and bladder frequency and decreased mechanical pain threshold, which was reversed by silodosin. WAS induced lymphocytic and mast cells infiltration in the mucosa and mild urothelial disruption, which was absent in WAS + S group. Alpha 1A adrenoceptor stimulation has an important role in the appearance of bladder pain in rats. Since BPS/IC patients present high levels of noradrenaline, alpha 1A stimulation may be an additional trigger for bladder dysfunction presented by these patients. Further studies will determine the clinical relevance of this finding in the treatment of BPS/IC patients.

Efficacy of transcranial direct-current stimulation in women with provoked vestibulodynia.

PubMed

Morin, Annie; Léonard, Guillaume; Gougeon, Véronique; Cyr, Marie-Pierre; Waddell, Guy; Bureau, Yves-André; Girard, Isabelle; Morin, Mélanie

2017-06-01

Provoked vestibulodynia is a highly prevalent condition characterized by acute recurrent pain located at the vaginal entrance in response to pressure application or attempted vaginal penetration. Despite a wide variety of treatments offered to women with provoked vestibulodynia, a high proportion of women are refractory to conventional treatment. Transcranial direct-current stimulation is a noninvasive brain stimulation technique that has been shown effective for improving various chronic pain conditions. Growing evidence suggests that the central nervous system could play a key role in provoked vestibulodynia. Targeting the central nervous system could therefore be a promising treatment for women with provoked vestibulodynia. The purpose of this study was to evaluate and compare the efficacy of active and sham transcranial direct-current stimulation in reducing pain intensity during intercourse in patients with provoked vestibulodynia. We conducted a triple-blind, parallel-group, randomized controlled trial. Women aged 17-45 years diagnosed with provoked vestibulodynia by a gynecologist using a validated protocol were randomized to 10 sessions of either active transcranial direct-current stimulation (intensity = 2 mA) or 10 sessions of sham transcranial direct-current stimulation, over a 2-week period. Both active and sham transcranial direct-current stimulation were applied for 20 minutes, with the anode positioned over the primary motor cortex, and the cathode over the contralateral supraorbital area. Outcome measures were collected at baseline, 2 weeks after treatment, and at 3-month follow-up by an evaluator blinded to group assignment. The primary objective was to assess pain intensity during intercourse, using a numerical rating scale. Secondary outcomes focused on sexual function and distress, vestibular sensitivity, psychological distress, treatment satisfaction, and patient impression of change. Statistical analyses were conducted on the intention-to-treat basis, and treatment effects were evaluated using a mixed linear model for repeated measures. A total of 40 patients were randomly assigned to receive either active (n = 20) or sham (n = 20) transcranial direct-current stimulation treatments from November 2014 through February 2016. Baseline characteristics were similar between the active and sham transcranial direct-current stimulation groups. In full compliance with the study protocol, every participant followed all courses of the study treatment, including assessments at 2-week and 3-month follow-up. Pain during sexual intercourse was not significantly different between active and sham treatment groups 2 weeks after treatment (P = .84) and at follow-up (P = .09). Mean baseline and 2-week assessment pain intensity were, respectively, 6.8 (95% confidence interval, 5.9-7.7) and 5.6 (95% confidence interval, 4.7-6.5) for active transcranial direct-current stimulation (P = .03) vs 7.5 (95% confidence interval, 6.6-8.4) and 5.7 (95% confidence interval, 4.8-6.6) for sham transcranial direct-current stimulation (P = .001). Nonsignificant differences between the 2 groups were also found in their sexual function and distress after treatment (P > .20) and at follow-up (P > .10). Overall, at 2-week assessment 68% assigned to active transcranial direct-current stimulation reported being very much, much, or slightly improved compared to 65% assigned to sham transcranial direct-current stimulation (P = .82), and still comparable at follow-up: 42% vs 65%, respectively (P = .15). Findings suggest that active transcranial direct-current stimulation is not more effective than sham transcranial direct-current stimulation for reducing pain in women with provoked vestibulodynia. Likewise, no significant effects were found on sexual function, vestibular sensitivity, or psychological distress. Copyright © 2017 Elsevier Inc. All rights reserved.

Dorsal Root Ganglion (DRG) Stimulation in the Treatment of Phantom Limb Pain (PLP).

PubMed

Eldabe, Sam; Burger, Katja; Moser, Heinrich; Klase, Daniel; Schu, Stefan; Wahlstedt, Anders; Vanderick, Bernard; Francois, Eric; Kramer, Jeffery; Subbaroyan, Jeyakumar

2015-10-01

Phantom limb pain (PLP) is a neuropathic condition in which pain is perceived as arising from an amputated limb. PLP is distinct from, although associated with, pain in the residual limb and nonpainful phantom sensations of the missing limb. Its treatment is extremely challenging; pharmaceutical options, while commonly employed, may be insufficient or intolerable. Neuromodulatory interventions such as spinal cord stimulation have generated mixed results and may be limited by poor somatotopic specificity. It was theorized that dorsal root ganglion (DRG) neuromodulation may be more effective. Patients trialed a DRG neurostimulation system for their PLP and were subsequently implanted if results were positive. Retrospective chart review was completed, including pain ratings on a 100-mm visual analogue scale (VAS) and patient-reported outcomes. Across eight patients, the average baseline pain rating was 85.5 mm. At follow-up (mean of 14.4 months), pain was rated at 43.5 mm. Subjective ratings of quality of life and functional capacity improved. Some patients reduced or eliminated pain medications. Patients reported precise concordance of the paresthesia with painful regions, including in their phantom limbs; in one case, stimulation eliminated PLP as well as nonpainful phantom sensations. Three patients experienced a diminution of pain relief, despite good initial outcomes. DRG neuromodulation may be an effective tool in treating this pain etiology. Clinical outcomes in this report support recent converging evidence suggesting that the DRG may be the site of PLP generation and/or maintenance. Further research is warranted to elucidate mechanisms and optimal treatment pathways. © 2015 International Neuromodulation Society.

Mesothalamic discharge in a chronic pain, allergy and fluid retention syndrome (case report).

PubMed

Andy, O J; Nicholas, W; Dearman, C

1995-01-01

A 32-year-old woman was bedridden for a year because of chronic pain and headaches. She had insomnia, depression, suicidal thoughts and a severe chemical allergy. She had been on steroid therapy for two years and became Cushingoid with striae in the arm pits, groins and abdomen. However, she had no hypertension, nor the buffalo fat and hirsutism. She was very edematous, with a weight gain from 112 to 180 lbs. The fluid retention did not conform to the syndrome of inappropriate antidiuretic hormone. Studies revealed abnormal scalp EEG discharges and high-voltage seizure discharges in the posterior thalamus. Electrothalamic stimulation suppressed the thalamic discharges and relieved the patient's pelvic pain and headaches. After one month of several thalamic stimulations per day, she was able to get out of bed and ambulate. In addition, the patient no longer was edematous and was tolerating perfumes and floor detergents. Steroids were progressively reduced without complications of withdrawal. She went from a completely steroid dependent state to independent during the first 1-1/2 yrs of thalamic stimulation. With continued thalamic stimulation she has done well for 8-1/2 yrs, weighs 112 lbs, keeps house and drives a car. It's speculated the illness is a chronic pain multiple syndrome predominantly due to mesothalamic discharges and body infirmities. The mesothalamic discharge implicated neural networks, which represent biologic systems, i.e. pain, sleep, fluid retention, etc. Therapeutic stimulation attenuates the discharges and the neural networks return to their normal set points of homeostasis.

Clinical effectiveness and cost-effectiveness of treatments for patients with chronic pain.

PubMed

Turk, Dennis C

2002-01-01

Chronic pain is a prevalent and costly problem. This review addresses the question of the clinical effectiveness and cost-effectiveness of the most common treatments for patients with chronic pain. Representative published studies that evaluate the clinical effectiveness of pharmacological treatments, conservative (standard) care, surgery, spinal cord stimulators, implantable drug delivery systems (IDDSs), and pain rehabilitation programs (PRPs) are examined and compared. The cost-effectiveness of these treatment approaches is also considered. Outcome criteria including pain reduction, medication use, health care consumption, functional activities, and closure of disability compensation cases are examined. In addition to clinical effectiveness, the cost-effectiveness of PRPs, conservative care, surgery, spinal cord stimulators, and IDDSs are compared using costs to return a treated patient to work to illustrate the relative expenses for each of these treatments. There are limitations to the success of all the available treatments. The author urges caution in interpreting the results, particularly in comparisons between treatments and across studies, because there are broad differences in the pain syndromes and inclusion criteria used, the drug dosages, comparability of treatments, the definition of "chronic" used, the outcome criteria selected to determine success, and societal differences. None of the currently available treatments eliminates pain for the majority of patients. Pain rehabilitation programs provide comparable reduction in pain to alternative pain treatment modalities, but with significantly better outcomes for medication use, health care utilization, functional activities, return to work, closure of disability claims, and with substantially fewer iatrogenic consequences and adverse events. Surgery, spinal cord stimulators, and IDDSs appear to have substantial benefits on some outcome criteria for carefully selected patients. These modalities are, however, expensive. Pain rehabilitation programs are significantly more cost effective than implantation of spinal cord stimulators, IDDSs, conservative care, and surgery, even for selected patients. Research is needed to identify which patients are most likely to benefit from the available treatments and to study combinations of the available treatments since none of them appear capable of eliminating pain or significantly improving functional outcomes for all treated.

Phantom limbs: pain, embodiment, and scientific advances in integrative therapies.

PubMed

Lenggenhager, Bigna; Arnold, Carolyn A; Giummarra, Melita J

2014-03-01

Research over the past two decades has begun to identify some of the key mechanisms underlying phantom limb pain and sensations; however, this continues to be a clinically challenging condition to manage. Treatment of phantom pain, like all chronic pain conditions, demands a holistic approach that takes into consideration peripheral, spinal, and central neuroplastic mechanisms. In this review, we focus on nonpharmacological treatments tailored to reverse the maladaptive neuroplasticity associated with phantom pain. Recent scientific advances emerging from interdisciplinary research between neuroscience, virtual reality, robotics, and prosthetics show the greatest promise for alternative embodiment and maintaining the integrity of the multifaceted representation of the body in the brain. Importantly, these advances have been found to prevent and reduce phantom limb pain. In particular, therapies that involve sensory and/or motor retraining, most naturally through the use of integrative prosthetic devices, as well as peripheral (e.g., transcutaneous electrical nerve stimulation) or central (e.g., transcranial magnetic stimulation or deep brain stimulation) stimulation techniques, have been found to both restore the neural representation of the missing limb and to reduce the intensity of phantom pain. While the evidence for the efficacy of these therapies is mounting, but well-controlled and large-scale studies are still needed. WIREs Cogn Sci 2014, 5:221-231. doi: 10.1002/wcs.1277 CONFLICT OF INTEREST: The authors have no financial or other relationship that might lead to a conflict of interest. For further resources related to this article, please visit the WIREs website. © 2014 John Wiley & Sons, Ltd.

Treatment-Limiting Complications of Percutaneous Spinal Cord Stimulator Implants: A Review of Eight Years of Experience From an Academic Center Database.

PubMed

Hayek, Salim M; Veizi, Elias; Hanes, Michael

2015-10-01

The study aims to evaluate the long-term implant survival and complications of spinal cord stimulation (SCS) leading to surgical revision or explant in patients treated for chronic noncancer pain. This is a retrospective study of all patients who underwent a percutaneous spinal cord stimulation trial followed by implant in an academic Pain Medicine division by four practitioners from 2007 to 2013, with follow-up data through April 2014. A total of 345 patients were considered candidates for dorsal column stimulation and underwent a trial. Two hundred thirty-four patients were implanted with an implant-to-trial ratio of 67-86% across various chronic pain entities (postlaminectomy syndrome, complex regional pain syndrome, small-fiber peripheral neuropathy, abdominal/pelvic pain, nonsurgical candidates with lumbosacral neuropathy, and neuropathic pain not otherwise specified), with the exception of nonsurgical candidates with lumbosacral neuropathy who had an implant ratio of 43%. The complication rate was 34.6%, with the hardware related being the most common reason, comprising 74.1% of all complications. The revision and explant rates were 23.9% each. The most common reason for explant was loss of therapeutic effect (41.1%). SCS is an effective treatment for chronic noncancer pain. It is a minimally invasive procedure, safe, and with good long-term outcomes. However, the surgical revision and explant rates are relatively high. As the use of SCS continues to grow, research into the causes of and risk factors for SCS-related complications is paramount to decrease complication rates in the future. © 2015 International Neuromodulation Society.

Laser stimulation of the acupoint 'Zusanli' (ST.36) on the radiopharmaceutical biodistribution in Wistar rats.

PubMed

Frederico, Éric H F F; Santos, Ailton A; Sá-Caputo, Danubia C C; Neves, Rosane F; Guimarães, Carlos A S; Chang, Shyang; Bernardo-Filho, Mario

2016-03-01

Laser used to stimulate acupoints is called laser acupuncture (LA). It is generally believed that similar clinical responses to manual acupuncture can be achieved. Here we analysed the effects of the laser (904 nm) at the 'Zusanli' acupoint (ST.36) of the stomach meridian on the biodistribution of the radiopharmaceutical Na(99m)TcO4. Wistar rats were divided into control (CG) and experimental groups (EG). The EG were exposed daily to the laser (904 nm) at ST.36 with 1 joule/min (40 mW/cm(2)) for 1 min. The animals of the CG were not exposed to laser at all. On the 8th day after LA, the animals were sedated and Na(99m)TcO4 was administered. After 10 min, the animals were all sacrificed and the organs removed. The radioactivity was counted in each organ to calculate the percentage of radioactivity of the injected dose per gram (%ATI/ g). Comparison of the %ATI/g in EG and CG was performed by Mann-Whitney test. The %ATI/g was significantly increased in the thyroid due to the stimulation of the ST.36 by laser. It is possible to conclude that the stimulation of ST.36 does lead to biological phenomena that interfere with the metabolism of the thyroid.

Subsurface optical stimulation of rat prostate cavernous nerves using a continuous wave, single mode, 1490 nm diode laser

NASA Astrophysics Data System (ADS)

Tozburun, Serhat; Stahl, Charlotte S. D.; Hutchens, Thomas C.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2013-03-01

Successful identification of the cavernous nerves (CN's) during radical prostatectomy requires detection of the CN's through a thin layer of overlying fascia. This study explores the 1490 nm infrared (IR) diode laser wavelength for rapid and deep subsurface CN stimulation in a rat model, in vivo. A 150-mW, 1490-nm diode laser providing an optical penetration depth of 520 μm was used to stimulate the CN's in 8 rats through a single mode fiber optic probe with 1-mm-diameter spot and 15 s irradiation time. Successful ONS was judged by an intracavernous pressure response (ICP) in the rat penis. Subsurface ONS at 1490 nm was also compared with previous studies using 1455 and 1550 nm IR diode laser wavelengths. ONS was observed through fascia layers up to 380 μm thick using an incident laser power of 50 mW. ICP response times as short as 4.6 +/- 0.2 s were recorded using higher laser powers bust still below the nerve damage threshold. The 1490-nm diode laser represents a compact, low cost, high power, and high quality infrared light source for use in ONS. This wavelength provides deeper optical penetration than 1455 nm and more rapid and efficient nerve stimulation than 1550 nm.

[Clinical observation on therapeutic effect of cupping combined with acupuncture stimulation at trigger points for lumbar myofascial pain syndrome].

PubMed

Zhao, Hong

2014-08-01

To observe the clinical effect of cupping combined with acupuncture stimulation of trigger points on lumbar myofascial pain syndrome (MPS). Sixty MPS patients were randomly divided into acupuncture + TDP group (n = 30), and cupping + acupuncture group (n = 30). Patients in the acupuncture + TDP group were treated by acupuncture stimulation of trigger points and local TDP irradiation, and patients of the cupping + acupuncture group treated by intensive cupping applied to the myofascial band and acupuncture stimulation of the locus according to the position of muscular tension band. The therapeutic effects were assessed according to the score of the McGill pain questionnaire composing of pain rating index (PRI), visual analogue scale (VAS) and present pain intensity (PPI) before, immediately and 1 month after the treatment. After the treatment, the total effective rates of the acupuncture+ TDP and cupping + acupuncture groups were 83.3% (25/30) and 96.6% (29/30), respectively, without significant difference between the two groups (P > 0.05). One month's follow-up showed that the total effective rates of the acupuncture + TDP and cupping + acupuncture groups were 40.0% and 90.0% respectively, and the latter group was significantly better than the acupuncture + TDP group in the therapeutic effect (P < 0.05). The scores of PRI, VAS, PPI after the treatment were markedly decreased in both groups (P < 0.05). One month later, the scores of PRI, VAS and PPI in the cupping + acupuncture group were obviously lower than those of the acupuncture group (P < 0.05). Both acupuncture stimulation of trigger points plus TDP and cupping plus acupuncture can effectively relieve pain in MPS patients, while the therapeutic effect of cupping plus acupuncture treatment lasts longer analgesic effect.

Pain-related somatosensory evoked potentials and functional brain magnetic resonance in the evaluation of neurologic recovery after cardiac arrest: a case study of three patients.

PubMed

Zanatta, Paolo; Messerotti Benvenuti, Simone; Baldanzi, Fabrizio; Bendini, Matteo; Saccavini, Marsilio; Tamari, Wadih; Palomba, Daniela; Bosco, Enrico

2012-03-31

This case series investigates whether painful electrical stimulation increases the early prognostic value of both somatosensory-evoked potentials and functional magnetic resonance imaging in comatose patients after cardiac arrest. Three single cases with hypoxic-ischemic encephalopathy were considered. A neurophysiological evaluation with an electroencephalogram and somatosensory-evoked potentials during increased electrical stimulation in both median nerves was performed within five days of cardiac arrest. Each patient also underwent a functional magnetic resonance imaging evaluation with the same neurophysiological protocol one month after cardiac arrest. One patient, who completely recovered, showed a middle latency component at a high intensity of stimulation and the activation of all brain areas involved in cerebral pain processing. One patient in a minimally conscious state only showed the cortical somatosensory response and the activation of the primary somatosensory cortex. The last patient, who was in a vegetative state, did not show primary somatosensory evoked potentials; only the activation of subcortical brain areas occurred. These preliminary findings suggest that the pain-related somatosensory evoked potentials performed to increase the prognosis of comatose patients after cardiac arrest are associated with regional brain activity showed by functional magnetic resonance imaging during median nerves electrical stimulation. More importantly, this cases report also suggests that somatosensory evoked potentials and functional magnetic resonance imaging during painful electrical stimulation may be sensitive and complementary methods to predict the neurological outcome in the acute phase of coma. Thus, pain-related somatosensory-evoked potentials may be a reliable and a cost-effective tool for planning the early diagnostic evaluation of comatose patients.

Comparison of the Effects of Manual Acupuncture, Laser Acupuncture, and Electromagnetic Field Stimulation at Acupuncture Point BL15 on Heart Rate Variability.

PubMed

Lee, Na Ra; Kim, Soo Byeong; Heo, Hyun; Lee, Yong Heum

2016-10-01

The aim of this study was to compare the influences of manual acupuncture, laser acupuncture, and electromagnetic field stimulation on the autonomic nervous system. We monitored the heart rate variability before and after stimulation to check the influence on the autonomic nervous system. The heart rate variabilities at low frequency (LF; 0.04-0.15 Hz) and high frequency (HF; 0.15-0.4 Hz) were analyzed to acquire LF/HF ratio. Xinshu (BL15) was selected as the stimulation point. Methods included manual acupuncture with a 1-cm depth and laser acupuncture at a wavelength of 660 nm and output power of 50 mW. An electromagnetic field of 2 Hz and 460 gauss (46 mT) was chosen. The LF and the LF/HF ratio were found to be lower in the manual acupuncture and the electromagnetic field groups, but to be higher in the laser acupuncture group. The HF was found to be lower in the laser acupuncture group, but higher in the manual acupuncture and the electromagnetic field groups. In conclusion, we found that manual acupuncture and electromagnetic field stimulation at BL15 activated the parasympathetic nervous system, whereas laser acupuncture at BL15 activated the sympathetic nervous system. Copyright © 2016. Published by Elsevier B.V.

Facet joint laser radiation: tissue effects of a new clinical laser application

NASA Astrophysics Data System (ADS)

Werkmann, Klaus; Thal, Dietmar R.

1996-01-01

Chronic unilateral and bilateral back pain with pseudoradicular symptoms, is a common clinical syndrome, which in many cases can be related to the facet joint syndrome. The pain is caused by mechanical affection of synovial and capsular nerve terminals. Therefore, current therapeutical attempts including physical therapy, intra-articular injection of local anesthetics and steroids and thermocoagulation of the facet joint with a thermocoagulator, are performed. We confirmed laser coagulation of the facet joint. Porcine cadaveric spines were treated immediately after death by intra-articular facet joint laser radiation. With the pulsed Nd:YAG laser (1064 nm) altogether 600 J were applied in three different places 4 mm apart at the top of the facet joint. The results showed that facet joint laser radiation leads to a small (about 1 - 2 mm diameter) lesion restricted to the facet joint cavity and its synovia. Histologically, we found a central carbonization zone and necrosis, including almost the whole cartilage and approximately 0.2 mm of the adjacent bone. These changes are similar to Nd:Yag-laser applications in other skeletal regions. It is suggested that these changes may lead to facet joint denervation by coagulation of the synovial nerve terminals. Cicatration of the laser lesion might cause ankylosis of this joint. In sum, facet joint laser radiation could be an alternative therapeutical tool for lower back pain of the facet joint syndrome type. Therefore, future clinical application of this technique seems to be very promising.

Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study.

PubMed

Russo, Marc; Cousins, Michael J; Brooker, Charles; Taylor, Nathan; Boesel, Tillman; Sullivan, Richard; Poree, Lawrence; Shariati, Nastaran Hesam; Hanson, Erin; Parker, John

2018-01-01

Conventional spinal cord stimulation (SCS) delivers a fixed-input of energy into the dorsal column. Physiologic effects such as heartbeat, respiration, spinal cord movement, and history of stimulation can cause both the perceived intensity and recruitment of stimulation to increase or decrease, with clinical consequences. A new SCS system controls stimulation dose by measuring the recruitment of fibers in the dorsal column and by using the amplitude of the evoked compound action potentials (ECAPs) to maintain stimulation within an individualized therapeutic range. Safety and efficacy of this closed-loop system was evaluated through six-month postimplantation. Chronic pain subjects with back and/or leg pain who were successfully trialed received a permanent system (Evoke; Saluda Medical, Sydney, Australia). Ratings of pain (100-mm visual analogue scale [VAS] and Brief Pain Instrument [BPI]), quality of life (EuroQol instrument [EQ-5D-5L]), function (Oswestry Disability Index [ODI]), and sleep (Pittsburgh Sleep Quality Index [PSQI]) were collected at baseline and repeated three and six months after implantation. Fifty-one subjects underwent a trial procedure; permanent implants were placed in 36 subjects. The proportion of subjects with ≥50% relief was 92.6% (back) and 91.3% (leg) at three months, and 85.7% (back) and 82.6% (leg) at six months. The proportion with ≥80% pain relief was 70.4% (back) and 56.5% (leg) at three months, and 64.3% (back) and 60.9% (leg) at six months. Statistically significant improvements in mean BPI, EQ-5D-5L, ODI, and PSQI were also observed at both time points. The majority of subjects experienced profound pain relief at three and six months, providing preliminary evidence for the effectiveness of the closed-loop SCS system. The exact mechanism of action for these outcomes is still being explored, although one likely hypothesis holds that ECAP feedback control may minimize recruitment of Aβ nociceptors and Aδ fibers during daily use of SCS. © 2017 International Neuromodulation Society.

Can combined use of low-level lasers and hyaluronic acid injections prolong the longevity of degenerative knee joints?

PubMed Central

Ip, David; Fu, Nga Yue

2015-01-01

Background This study evaluated whether half-yearly hyaluronic acid injection together with low-level laser therapy in addition to standard conventional physical therapy can successfully postpone the need for joint replacement surgery in elderly patients with bilateral symptomatic tricompartmental knee arthritis. Methods In this prospective, double-blind, placebo-controlled study, 70 consecutive unselected elderly patients with bilateral tricompartmental knee arthritis were assigned at random to either one of two conservative treatment protocols to either one of the painful knees. Protocol A consisted of conventional physical therapy plus a sham light source plus saline injection, and protocol B consisted of protocol A with addition of half-yearly hyaluronic acid injection as well as low-level laser treatment instead of using saline and a sham light source. Treatment failure was defined as breakthrough pain necessitating joint replacement. Results Among the 140 painful knees treated with either protocol A or protocol B, only one of the 70 painful knees treated by protocol B required joint replacement, whereas 15 of the 70 painful knees treated by protocol A needed joint replacement surgery (P<0.05). Conclusion We conclude that half-yearly hyaluronic acid injections together with low-level laser therapy should be incorporated into the standard conservative treatment protocol for symptomatic knee arthritis, because it may prolong the longevity of the knee joint without the need for joint replacement. PMID:26346122

A review of heat transfer in human tooth--experimental characterization and mathematical modeling.

PubMed

Lin, Min; Xu, Feng; Lu, Tian Jian; Bai, Bo Feng

2010-06-01

With rapid advances in modern dentistry, high-energy output instruments (e.g., dental lasers and light polymerizing units) are increasingly employed in dental surgery for applications such as laser assisted tooth ablation, bleaching, hypersensitivity treatment and polymerization of dental restorative materials. Extreme high temperature occurs within the tooth during these treatments, which may induce tooth thermal pain (TTP) sensation. Despite the wide application of these dental treatments, the underlying mechanisms are far from clear. Therefore, there is an urgent need to better understand heat transfer (HT) process in tooth, thermally induced damage of tooth, and the corresponding TTP. This will enhance the design and optimization of clinical treatment strategies. This paper presents the state-of-the-art of the current understanding on HT in tooth, with both experimental study and mathematical modeling reviewed. Limitations of the current experimental and mathematical methodologies are discussed and potential solutions are suggested. Interpretation of TTP in terms of thermally stimulated dentinal fluid flow is also discussed. Copyright (c) 2010 Academy of Dental Materials. All rights reserved.

The effect of low level laser therapy in different wavelengths in the treatment of oral mucositis—proposal for extra-oral implementation

NASA Astrophysics Data System (ADS)

Moraes, J. J. C.; Queiroga, A. S.; de Biase, R. C. C. G.; Leite, E. P.; Cabral Júnior, C. R.; Limeira Júnior, F. A.

2009-09-01

The oral mucositis is the most frequent acute oral complication resulting from antineoplastic treatment and may worsen the clinical condition of the patient and interfere with his/her quality of life. This study aimed to comparatively evaluate, from a clinical point of view, the effect of Laser Therapy λ660 nm (wavelength of the red Laser) and λ830 nm (wavelength of the infrared Laser), at extra-oral points, in remission of severity of oral mucositis and pain associated with it in pediatric oncological patients undergoing chemotherapy with the anticancer drug methotrexate, noting which of the two wavelength is the most appropriate to this new technique. The sample consisted of 13 patients placed at random in each group and subjected to sessions of Low Level Laser Therapy, at pre-determined extra-oral points for five consecutive days, starting at the beginning of the observation of mucositis injuries. It became possible to note that from the group of patients in the group of Laser λ830 nm ( n = 6; 46.15%), four ( n = 4; 66.67%) of these patients had remission of injuries to grade 0 (WHO), and as for pain, five patients ( n = 5; 83.33%) showed no painful symptoms for mucositis injuries. In the Laser λ660 nm group ( n = 7; 53.85%), only two patients ( n = 2; 28.57%) achieved a regression of lesions to grade 0 (WHO), while four patients ( n = 4; 57.14%) had no pain. So, the extra-oral application of Laser Therapy was effective in treating injuries of oral mucositis in the patients treated; and Laser Therapy in the infrared spectrum (λ830 nm) was more effective in the treatment of oral mucositis injuries compared to the red spectrum (λ660 nm), which can be explained by the greater power of penetration of infrared rays, acting in a more expressive way in deeper places.

A Micro-Electrode Array device coupled to a laser-based system for the local stimulation of neurons by optical release of glutamate.

PubMed

Ghezzi, Diego; Menegon, Andrea; Pedrocchi, Alessandra; Valtorta, Flavia; Ferrigno, Giancarlo

2008-10-30

Optical stimulation is a promising approach to investigate the local dynamic responses of cultured neurons. In particular, flash photolysis of caged compounds offers the advantage of allowing the rapid change of concentration of either extracellular or intracellular molecules, such as neurotransmitters or second messengers, for the stimulation or modulation of neuronal activity. We describe here the use of an ultra-violet (UV) laser diode coupled to an optical fibre for the local activation of caged compounds combined with a Micro-Electrode Array (MEA) device. Local uncaging was achieved by UV irradiation through the optical fibre previously positioned by using a red laser diode. The size of the stimulation was determined using caged fluorescein, whereas its efficacy was tested by studying the effect of uncaging the neurotransmitter glutamate. Uncaged glutamate evoked neuronal responses that were recorded using either fluorescence measurements or electrophysiological recordings with MEAs, thus showing the ability of our system to induce local neuronal excitation. This method allows overcoming the limitations of the MEA system related to unfocused electrical stimulation and induction of electrical artefacts. In addition, the coupling of a UV laser diode to an optical fibre allows a precise local stimulation and a quick change of the stimulation point.

How Does Anodal Transcranial Direct Current Stimulation of the Pain Neuromatrix Affect Brain Excitability and Pain Perception? A Randomised, Double-Blind, Sham-Control Study

PubMed Central

Vaseghi, Bita; Zoghi, Maryam; Jaberzadeh, Shapour

2015-01-01

Background Integration of information between multiple cortical regions of the pain neuromatrix is thought to underpin pain modulation. Although altered processing in the primary motor (M1) and sensory (S1) cortices is implicated in separate studies, the simultaneous changes in and the relationship between these regions are unknown yet. The primary aim was to assess the effects of anodal transcranial direct current stimulation (a-tDCS) over superficial regions of the pain neuromatrix on M1 and S1 excitability. The secondary aim was to investigate how M1 and S1 excitability changes affect sensory (STh) and pain thresholds (PTh). Methods Twelve healthy participants received 20 min a-tDCS under five different conditions including a-tDCS of M1, a-tDCS of S1, a-tDCS of DLPFC, sham a-tDCS, and no-tDCS. Excitability of dominant M1 and S1 were measured before, immediately, and 30 minutes after intervention respectively. Moreover, STh and PTh to peripheral electrical and mechanical stimulation were evaluated. All outcome measures were assessed at three time-points of measurement by a blind rater. Results A-tDCS of M1 and dorsolateral prefrontal cortex (DLPFC) significantly increased brain excitability in M1 (p < 0.05) for at least 30 min. Following application of a-tDCS over the S1, the amplitude of the N20-P25 component of SEPs increased immediately after the stimulation (p < 0.05), whilst M1 stimulation decreased it. Compared to baseline values, significant STh and PTh increase was observed after a-tDCS of all three stimulated areas. Except in M1 stimulation, there was significant PTh difference between a-tDCS and sham tDCS. Conclusion a-tDCS of M1 is the best spots to enhance brain excitability than a-tDCS of S1 and DLPFC. Surprisingly, a-tDCS of M1 and S1 has diverse effects on S1 and M1 excitability. A-tDCS of M1, S1, and DLPFC increased STh and PTh levels. Given the placebo effects of a-tDCS of M1 in pain perception, our results should be interpreted with caution, particularly with respect to the behavioural aspects of pain modulation. Trial Registration Australian New Zealand Clinical Trials, ACTRN12614000817640, http://www.anzctr.org.au/. PMID:25738603

Effect of analgesic nerve block electrical stimulation in a patient with adhesive capsulitis.

PubMed

Gulick, Dawn T; Borger, Amy; McNamee, Lauren

2007-01-01

Although the pathophysiology of adhesive capsulitis is poorly understood, the primary goal of therapeutic intervention is to restore pain-free, functional range of motion (ROM) of the shoulder. Pain and muscle guarding, particularly of the subscapularis muscle, are common impairments that occur with adhesive capsulitis. The purpose of this case report is to describe a novel approach to help the pain-muscle guarding-pain cycle associated with pain and limited shoulder motion in a patient with a medical diagnosis of adhesive capsulitis. The patient was a 64-year-old female with adhesive capsulitis. Outcome variables were the Shoulder Pain and Disability Index (SPADI), internal rotation (IR) and external rotation (ER) ROM, and rotational lack. Twelve treatments of moist heat, analgesic nerve block electrical stimulation, contract/relax exercises for shoulder IR/ER, and Pendulum/Codman exercises were administered. After both 2 and 4 weeks of treatment, the patient demonstrated marked improvements in all areas. Overall, there was a 78-106% increase in ROM (IR and ER) and a 50-83% improvement in functional mobility (rotational lack & SPADI). It appears that analgesic electrical stimulation may have helped decrease the pain-muscle guarding cycle associated with adhesive capsulitis to enhance functional outcomes in a timely manner.

Low-frequency brain stimulation to the left dorsolateral prefrontal cortex increases the negative impact of social exclusion among those high in personal distress.

PubMed

Fitzgibbon, Bernadette Mary; Kirkovski, Melissa; Bailey, Neil Wayne; Thomson, Richard Hilton; Eisenberger, Naomi; Enticott, Peter Gregory; Fitzgerald, Paul Bernard

2017-06-01

The dorsolateral prefrontal cortex (DLPFC) is thought to play a key role in the cognitive control of emotion and has therefore, unsurprisingly, been implicated in the regulation of physical pain perception. This brain region may also influence the experience of social pain, which has been shown to activate similar neural networks as seen in response to physical pain. Here, we applied sham or active low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC, previously shown to exert bilateral effects in pain perception, in healthy participants. Following stimulation, participants played the "Cyberball Task"; an online ball-tossing game in which the subject participant is included or excluded. Compared to sham, rTMS did not modulate behavioural response to social exclusion. However, within the active rTMS group only, greater trait personal distress was related to enhanced negative outcomes to social exclusion. These results add further support to the notion that the effect of brain stimulation is not homogenous across individuals, and indicates the need to consider baseline individual differences when assessing response to brain stimulation. This seems particularly relevant in social neuroscience investigations, where trait factors may have a meaningful effect.

Palmar skin conductance variability and the relation to stimulation, pain and the motor activity assessment scale in intensive care unit patients.

PubMed

Günther, Anders C; Bottai, Matteo; Schandl, Anna R; Storm, Hanne; Rossi, Patrik; Sackey, Peter V

2013-03-19

Many intensive care unit (ICU) patients describe pain and other adverse feelings that may impact long-term psychological morbidity. Sympathetically mediated palmar skin conductance variability is related to emotionally induced perspiration and correlates with pain levels in the perioperative setting but has not been studied in ICU patients. Twenty non-intubated and 20 intubated general ICU patients were included in this observational study. Patients were monitored with the MED-STORM Pain Monitoring System®. The number of skin conductance fluctuations per second (NSCF) was measured in parallel with bedside observation during one hour of intensive care, including rest, procedures and patient-staff interactions. Arousal-agitation level was monitored with the motor activity assessment scale (MAAS). Pain was monitored with the numeric rating scale (0 to 10) in patients able to communicate or by observation in patients unable to communicate. In non-intubated patients, NSCF increased with increasing stimulation/pain but also with higher MAAS (P=0.002). An interaction effect was found, with increased NSCF response to stimulation/pain with increasing MAAS (P<0.001). In critically ill patients, NSCF may be more useful evaluating emotional distress rather than pain alone. It needs to be assessed whether NSCF monitoring is clinically useful and whether controlling emotional distress with the aid of such monitoring may impact on patient care and outcomes.

Spinal cord stimulation for FBSS and CRPS: A review of 80 cases with on-table trial of stimulation.

PubMed

Gopal, Hari; Fitzgerald, Joseph; McCrory, Connail

2016-01-01

Spinal cord stimulation (SCS) is used for the treatment of chronic neuropathic pain, a notoriously difficult condition to treat. Failed Back Surgery Syndrome (FBSS) and Complex Regional Pain syndrome (CRPS) remain the strongest indications. Funding remains a difficult issue and the use of trial of stimulation is the traditional method of ensuring best outcomes from implantation. A retrospective and consecutive review of 80 cases of spinal cord stimulation for patients with a diagnosis of FBSS and CRPS having undergone prior comprehensive medical management and interventional treatment with no sustained benefit. Trial of stimulation was performed on-table and if acceptable coverage was achieved, the case proceeded to full implantation. The mean patient age was 50.08 years (range 28-80 years). At 12 months follow-up, thirty two patients (40%) no longer required analgesic medication. Thirty patients (37.5%) reported their pain was manageable with first line analgesics. Fourteen (17.5%) reported their pain was manageable first line analgesic and occasional tramadol or codeine. Four (5%) reported that their pain was manageable with NSAID's, paracetamol, amitriptyline, and regular codeine or tramadol. Seventeen out of eighty patients (21.25%) were unemployed before SCS implant, and at 12 months follow up eight of these patients (47.05%) had returned to work. There was no infective complications or explants. Two patients (2.53%) required one lead revision, which was successful. SCS is the most effective treatment for FBSS and CRPS, which is proven resistant to medical management. On-table trial and implantation is easy to perform with good success rate and low morbidity and if successful will reduce complication rates, especially infection.

Is Life better after motor cortex stimulation for pain control? Results at long-term and their prediction by preoperative rTMS.

PubMed

André-Obadia, Nathalie; Mertens, Patrick; Lelekov-Boissard, Taïssia; Afif, Afif; Magnin, Michel; Garcia-Larrea, Luis

2014-01-01

A positive effect of motor cortex stimulation (MCS) (defined as subjective estimations of pain relief ≥ 30%) has been reported in 55 - 64% of patients. Repetitive magnetic cortical stimulation (rTMS) is considered a predictor of MCS effect. These figures are, however, mostly based on subjective reports of pain intensity, and have not been confirmed in the long-term. This study assessed long-term pain relief (2 - 9 years) after epidural motor cortex stimulation and its pre-operative prediction by rTMS, using both intensity and Quality of Life (QoL) scales. Analysis of the long-term evolution of pain patients treated by epidural motor cortex stimulation, and predictive value of preoperative response to rTMS. University Neurological Hospital Pain Center. Twenty patients suffering chronic pharmaco-resistant neuropathic pain. All patients received first randomized sham vs. active 20 Hz-rTMS, before being submitted to MCS surgery. Postoperative pain relief was evaluated at 6 months and then up to 9 years post-MCS (average 6.1 ± 2.6 y) using (i) pain numerical rating scores (NRS); (ii) a combined assessment (CPA) including NRS, drug intake, and subjective quality of life; and (iii) a short questionnaire (HowRu) exploring discomfort, distress, disability, and dependence. Pain scores were significantly reduced by active (but not sham) rTMS and by subsequent MCS. Ten out of 20 patients kept a long-term benefit from MCS, both on raw pain scores and on CPA. The CPA results were strictly comparable when obtained by the surgeon or by a third-party on telephonic survey (r = 0.9). CPA scores following rTMS and long-term MCS were significantly associated (Fisher P = 0.02), with 90% positive predictive value and 67% negative predictive value of preoperative rTMS over long-term MCS results. On the HowRu questionnaire, long-term MCS-related improvement concerned "discomfort" (physical pain) and "dependence" (autonomy for daily activities), whereas "disability" (work, home, and leisure activities) and "distress" (anxiety, stress, depression) did not significantly improve. Limited cohort of patients with inhomogeneous pain etiology. Subjectivity of the reported items by the patient after a variable and long delay after surgery. Predictive evaluation based on a single rTMS session compared to chronic MCS. Half of the patients still retain a significant benefit after 2 - 9 years of continuous MCS, and this can be reasonably predicted by preoperative rTMS. Adding drug intake and QoL estimates to raw pain scores allows a more realistic assessment of long-term benefits and enhance the rTMS predictive value. The aims of this study and its design were approved by the local ethics committee (University Hospitals St Etienne and Lyon, France).

Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?

PubMed Central

Tashani, O; Johnson, MI

2009-01-01

Transcutaneous electrical nerve stimulation (TENS) refers to the delivery of electrical currents through the skin to activate peripheral nerves. The technique is widely used in developed countries to relieve a wide range of acute and chronic pain conditions, including pain resulting from cancer and its treatment. There are many systematic reviews on TENS although evidence is often inconclusive because of shortcomings in randomised control trials methodology. In this overview the basic science behind TENS will be discussed, the evidence of its effectiveness in specific clinical conditions analysed and a case for its use in pain management in developing countries will be made. PMID:21483510

Pain and the defense response: structural equation modeling reveals a coordinated psychophysiological response to increasing painful stimulation.

PubMed

Donaldson, Gary W; Chapman, C Richard; Nakamura, Yoshi; Bradshaw, David H; Jacobson, Robert C; Chapman, Christopher N

2003-03-01

The defense response theory implies that individuals should respond to increasing levels of painful stimulation with correlated increases in affectively mediated psychophysiological responses. This paper employs structural equation modeling to infer the latent processes responsible for correlated growth in the pain report, evoked potential amplitudes, pupil dilation, and skin conductance of 92 normal volunteers who experienced 144 trials of three levels of increasingly painful electrical stimulation. The analysis assumed a two-level model of latent growth as a function of stimulus level. The first level of analysis formulated a nonlinear growth model for each response measure, and allowed intercorrelations among the parameters of these models across individuals. The second level of analysis posited latent process factors to account for these intercorrelations. The best-fitting parsimonious model suggests that two latent processes account for the correlations. One of these latent factors, the activation threshold, determines the initial threshold response, while the other, the response gradient, indicates the magnitude of the coherent increase in response with stimulus level. Collectively, these two second-order factors define the defense response, a broad construct comprising both subjective pain evaluation and physiological mechanisms.

Peripheral Nerve Stimulation for Painful Mononeuropathy Secondary to Leprosy: A 12-Month Follow-Up Study.

PubMed

Freitas, Tiago da Silva; Fonoff, Erich Talamoni; Marquez Neto, Oswaldo Ribeiro; Kessler, Iruena Moraes; Barros, Laura Mendes; Guimaraes, Ronan Wilk; Azevedo, Monalisa Ferreira

2018-04-01

Leprosy affects approximately 10-15 million patients worldwide and remains a relevant public health issue. Chronic pain secondary to leprosy is a primary cause of morbidity, and its treatment remains a challenge. We evaluated the feasibility and safety of peripheral nerve stimulation (PNS) for painful mononeuropathy secondary to leprosy that is refractory to pharmacological therapy and surgical intervention (decompression). Between 2011 and 2013 twenty-three patients with painful mononeuropathy secondary to leprosy were recruited to this prospective case series. All patients were considered to be refractory to optimized conservative treatment and neurosurgical decompression. Pain was evaluated over the course of the study using the neuropathic pain scale and the visual analog scale for pain. In the first stage, patients were implanted with a temporary electrode that was connected to an external stimulator, and were treated with PNS for seven days. Patients with 50% or greater pain relief received a definitive implantation in the second stage. Follow-ups in the second stage were conducted at 1, 3, 6, and 12 months. After seven days of trial in the first stage, 10 patients showed a pain reduction of 50% or greater. At 12-month follow-up in the second stage, 6 of the 10 patients who underwent permanent device implantation showed a pain reduction of 50% or greater (75% reduction on average), and two patients showed a 30% reduction in pain. Two patients presented with electrode migration that required repositioning during the 12-month follow-up period. Our data suggest that PNS might have significant long-term utility for the treatment of painful mononeuropathy secondary to leprosy. Future studies should be performed in order to corroborate our findings in a larger population and encourage the clinical implementation of this technique. © 2017 International Neuromodulation Society.

Naproxen effects on brain response to painful pressure stimulation in patients with knee osteoarthritis: a double-blind, randomized, placebo-controlled, single-dose study.

PubMed

Giménez, Mónica; Pujol, Jesús; Ali, Zahid; López-Solà, Marina; Contreras-Rodríguez, Oren; Deus, Joan; Ortiz, Héctor; Soriano-Mas, Carles; Llorente-Onaindia, Jone; Monfort, Jordi

2014-11-01

The aim of our study was to investigate the effects of naproxen, an antiinflammatory analgesic drug, on brain response to painful stimulation on the affected knee in chronic osteoarthritis (OA) using functional magnetic resonance imaging (fMRI) in a double-blind, placebo-controlled study. A sample of 25 patients with knee OA received naproxen (500 mg), placebo, or no treatment in 3 separate sessions in a randomized manner. Pressure stimulation was applied to the medial articular interline of the knee during the fMRI pain sequence. We evaluated subjective pain ratings at every session and their association with brain responses to pain. An fMRI control paradigm was included to discard global brain vascular effects of naproxen. We found brain activation reductions under naproxen compared to no treatment in different cortical and subcortical core pain processing regions (p≤0.001). Compared to placebo, naproxen triggered an attenuation of amygdala activation (p=0.001). Placebo extended its attenuation effects beyond the classical pain processing network (p≤0.001). Subjective pain scores during the fMRI painful task differed between naproxen and no treatment (p=0.037). Activation attenuation under naproxen in different regions (i.e., ventral brain, cingulate gyrus) was accompanied by an improvement in the subjective pain complaints (p≤0.002). Naproxen effectively reduces pain-related brain responses involving different regions and the attenuation is related to subjective pain changes. Our current work yields further support to the utility of fMRI to objectify the acute analgesic effects of a single naproxen dose in patients affected by knee OA. The trial was registered at the EuropeanClinicalTrials Database, "EudraCT Number 2008-004501-33".

Effectiveness of Low-Level Laser Therapy in Reducing Orthodontic Pain: A Systematic Review and Meta-Analysis

PubMed Central

Deana, Naira Figueiredo; Zaror, Carlos; Sandoval, Paulo

2017-01-01

Objectives To assess the effectiveness of low-level laser therapy (LLLT) in reducing orthodontic pain after the application of orthodontic force (OF). Methods A systematic search was conducted in the MEDLINE, EMBASE, Scopus, Cochrane Library, Web of Science, and EBSCOhost databases. The study included randomized clinical trials (RCT) which analysed the effectiveness of LLLT in reducing orthodontic pain assessed at 24 and 72 hrs after the application of OF. The risk of bias of the eligible trials was assessed using the Cochrane Collaboration's risk of bias tool. Standard mean difference was calculated and pooled by meta-analysis using random effect models. Results Of 467 identified articles, 20 RCT were finally included. In the risk of bias assessments, 13 studies presented a high risk, 5 an unclear risk, and 2 a low risk. The meta-analysis showed that in patients treated with laser versus placebo there was a difference in favour of LLLT in spontaneous pain 24 and 72 hrs after the installation of light archwires and spontaneous pain and chewing pain 24 and 72 hrs after the installation of elastomeric separators. Conclusions LLLT proved to be effective in promoting a reduction in spontaneous and chewing pain after the application of OF; however, the poor quality of the evidence requires these results to be treated with caution. PMID:29089818

Laser acupuncture reduces pain in pediatric kidney biopsies: a randomized controlled trial.

PubMed

Oates, Aris; Benedict, Kelly A; Sun, Karen; Brakeman, Paul R; Lim, Jessica; Kim, Cynthia

2017-01-01

Evaluate laser acupuncture (LA) as an adjuvant therapy in pain management during percutaneous kidney biopsy procedure in children and adolescents. This prospective, double-blinded, randomized controlled trial enrolled patients aged 7 to 26 years admitted to a children's hospital for percutaneous kidney biopsy. Patients received LA to treatment points (acupuncture group) or sham points (control group) before the procedure. The laser delivered a dose of 42 J/cm over 10 acupoints. Patients and parents rated the pain during and after the biopsy, and change in pain scores were calculated for each patient. Anxiety, vital signs, sedation medication, and patient's biopsy experience were secondary outcomes. Sixty-nine treatments (33 in the acupuncture group and 36 in the control group) were eligible for analysis. Patients in the acupuncture group reported a significantly improved change in the pain score after the biopsy compared with the controls (0.8 vs -0.5, P = 0.044). Patients in the acupuncture group had a statistically significant decrease in procedure vital signs including heart rate (-1.8 vs 5.6, P = 0.043) and respiratory rate (-2.4 vs 0.4, P = 0.045) when compared with controls. Parents also perceived a correspondingly greater improvement in their child's pain for those in the acupuncture group compared with the controls (2.3 vs 0.3, P = 0.04). Adjunctive LA significantly improved pain after pediatric percutaneous kidney biopsies.

Comparison of percutaneous electrical nerve stimulation with transcutaneous electrical nerve stimulation for long-term pain relief in patients with chronic low back pain.

PubMed

Yokoyama, Masataka; Sun, Xiaohui; Oku, Satoru; Taga, Naoyuki; Sato, Kenji; Mizobuchi, Satoshi; Takahashi, Toru; Morita, Kiyoshi

2004-06-01

The long-term effect of percutaneous electrical nerve stimulation (PENS) on chronic low back pain (LBP) is unclear. We evaluated the number of sessions for which PENS should be performed to alleviate chronic LBP and how long analgesia is sustained. Patients underwent treatment on a twice-weekly schedule for 8 wk. Group A (n = 18) received PENS for 8 wk, group B (n = 17) received PENS for the first 4 wk and transcutaneous electrical nerve stimulation (TENS) for the second 4 wk, and group C (n = 18) received TENS for 8 wk. Pain level, degree of physical impairment, and the daily intake of nonsteroidal antiinflammatory drugs (NSAIDs) were assessed before the first treatment, 3 days after Week 2, Week 4, and Week 8 treatments, and at 1 and 2 mo after the sessions. During PENS therapy, the pain level decreased significantly from Week 2 in Groups A and B (P < 0.05 or 0.01), and physical impairment and required NSAIDs decreased significantly from Week 4 (P < 0.05 or 0.01) in Group A but only at Week 4 in Group B (P < 0.05 or 0.01). These effects were sustained until 1-mo follow-up (P < 0.01) in Group A but not in Group B; these effects were not observed at 2-mo follow-up even in Group A. In Group C, pain level decreased significantly only at Week 8 (P < 0.05). Our results indicate that repeated PENS is more effective than TENS for chronic LBP but must be continued to sustain the analgesic effect. A cumulative analgesic effect was observed in patients with chronic low back pain (LBP) after repeated percutaneous electrical nerve stimulation (PENS), but this effect gradually faded after the treatment was terminated. Results indicate that although PENS is effective for chronic LBP, treatments need to be continued to sustain analgesia.

Parameter Optimization Analysis of Prolonged Analgesia Effect of tDCS on Neuropathic Pain Rats

PubMed Central

Wen, Hui-Zhong; Gao, Shi-Hao; Zhao, Yan-Dong; He, Wen-Juan; Tian, Xue-Long; Ruan, Huai-Zhen

2017-01-01

Background: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications. PMID:28659772

Bibliography of Soviet Laser Developments, Number 44 November - December 1979.

DTIC Science & Technology

1980-08-13

Laser Materials, Ultrashort Pulse Generation, X-ray Lasers , Gamma Lasers , Laser Theory, Laser Biological Effects, Laser Communications, Laser Beam... lasers ; components; nonlinear optics; spectroscopy of laser materials; ultrashort pulse generation; theoretical aspects of advanced lasers ; and...and V.P. Feshchenko (51). Stimulated Raman scattering in absorbing media during pumping by ultrashort laser

Noninvasive transcranial direct current stimulation (tDCS) for the treatment of orofacial pain.

PubMed

Fricova, Jitka; Englerova, Katerina; Rokyta, Richard

2016-10-01

tDCS is a promising method for the treatment of chronic pain. Electrode placement locations must be chosen in accordance with the density and the time course of the current in order to prevent pathological changes in the underlying tissue. In order to reduce current spatial variability, more electrodes of the same polarity are placed in a circle around the second electrode of the opposite polarity. The applied current produced the greatest changes directly beneath the electrodes: the cathode reduces the excitability of cortical neurons, while the anode has the opposite effect. Based on inclusion criteria, 10 patients with chronic orofacial pain, secondary trigeminal neuralgia after oral surgery, were enrolled and underwent both anode and cathode stimulation. Before the first session we measured pain intensity on a numeric pain rating scale and tactile and thermal stimulation were used to assess somatosensory status. tDCS was applied for five consecutive days. At the end of tDCS application, somatosensory status was assessed again. From our results we can conclude that the application of tDCS improves the perception of some types of pain. When we increase our sample size, we would expect confirmation not only on our positive results, but also some additional findings for explaining the pathophysiology of orofacial pain. These pathophysiological findings and explanations are very important for the application of tDCS in the treatment of orofacial pain and also for other types of neuropathic pain.

Fractional CO2 Laser Treatment of the Vestibule for Patients with Vestibulodynia and Genitourinary Syndrome of Menopause: A Pilot Study.

PubMed

Murina, Filippo; Karram, Mickey; Salvatore, Stefano; Felice, Raffaele

2016-12-01

Chronic vulvar pain and burning remains one of the most perplexing problems faced by practicing gynecologists. To evaluate the effectiveness and safety of the application of micro-ablative fractional CO 2 laser to the vulvar vestibule in the management of patients with vulvar pain from vestibulodynia or genitourinary syndrome of menopause. Patients (N = 70) underwent fractional micro-ablative CO 2 laser treatment for vestibular pain plus vestibulodynia (n = 37) or genitourinary syndrome of menopause (n = 33). Inclusion criteria were the existence of vestibular atrophic changes and the absence of moderate or severe pelvic floor hypertonic dysfunction. A visual analog scale of pain and the Marinoff score of dyspareunia were chosen to evaluate improvement. Grading of vestibular health also was quantified using a four-point scoring system (0 = no atrophy, 3 = severe atrophy). Data were collected at baseline, at weeks 4, 8, and 12, and 4 months after the final treatment. For visual analog scale and dyspareunia scoring and for the overall vestibular health index scoring, statistically significant improvement was noted after three sessions of vestibular fractional CO 2 laser treatment. Improvement gradually increased throughout the study period and was maintained through the 4-month follow-up visit. There was no statistically significant difference in outcomes between the two study groups. No adverse events from fractional CO 2 laser treatment were noted. Overall, 67.6% of patients stated significant improvement from the laser procedure. This preliminary case series showed encouraging results using fractional CO 2 laser treatment of the vestibule in women with vestibulodynia and genitourinary syndrome of menopause. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Efficacy of different therapy regimes of low-power laser in painful osteoarthritis of the knee: a double-blind and randomized-controlled trial.

PubMed

Gur, Ali; Cosut, Abdulkadir; Sarac, Aysegul Jale; Cevik, Remzi; Nas, Kemal; Uyar, Asur

2003-01-01

A prospective, double-blind, randomized, and controlled trial was conducted in patients with knee osteoarthritis (OA) to evaluate the efficacy of infrared low-power Gallium-Arsenide (Ga-As) laser therapy (LPLT) and compared two different laser therapy regimes. Ninety patients were randomly assigned to three treatment groups by one of the nontreating authors by drawing 1 of 90 envelopes labeled 'A' (Group I: actual LPLT consisted of 5 minutes, 3 J total dose + exercise; 30 patients), 'B' (Group II: actual LPLT consisted of 3 minutes, 2 J total dose + exercise; 30 patients), and 'C' (Group III: placebo laser group + exercise; 30 patients). All patients received a total of 10 treatments, and exercise therapy program was continued during study (14 weeks). Subjects, physician, and data analysts were unaware of the code for active or placebo laser until the data analysis was complete. All patients were evaluated with respect to pain, degree of active knee flexion, duration of morning stiffness, painless walking distance and duration, and the Western Ontario and Mc Master Universities Osteoarthritis Index (WOMAC) at week 0, 6, 10, and 14. Statistically significant improvements were indicated in respect to all parameters such as pain, function, and quality of life (QoL) measures in the post-therapy period compared to pre-therapy in both active laser groups (P < 0.01). Improvements in all parameters of the Group I and in parameters, such as pain and WOMAC of the Group II, were more statistically significant when compared with placebo laser group (P < 0.05). Our study demonstrated that applications of LPLT in different dose and duration have not affected results and both therapy regimes were a safe and effective method in treatment of knee OA. Copyright 2003 Wiley-Liss, Inc.

Optical stimulation of the prostate nerves: A potential diagnostic technique

NASA Astrophysics Data System (ADS)

Tozburun, Serhat

There is wide variability in sexual potency rates (9--86%) after nerve-sparing prostate cancer surgery due to limited knowledge of the location of the cavernous nerves (CN's) on the prostate surface, which are responsible for erectile function. Thus, preservation of the CN's is critical in preserving a man's ability to have spontaneous erections following surgery. Nerve-mapping devices, utilizing conventional Electrical Nerve Stimulation (ENS) techniques, have been used as intra-operative diagnostic tools to assist in preservation of the CN. However, these technologies have proven inconsistent and unreliable in identifying the CN's due to the need for physical contact, the lack of spatial selectivity, and the presence of electrical artifacts in measurements. Optical Nerve Stimulation (ONS), using pulsed infrared laser radiation, is studied as an alternative to ENS. The objective of this study is sevenfold: (1) to develop a laparoscopic laser probe for ONS of the CN's in a rat model, in vivo; (2) to demonstrate faster ONS using continuous-wave infrared laser radiation; (3) to describe and characterize the mechanism of successful ONS using alternative laser wavelengths; (4) to test a compact, inexpensive all-single-mode fiber configuration for optical stimulation of the rat CN studies; (5) to implement fiber optic beam shaping methods for comparison of Gaussian and flat-top spatial beam profiles during ONS; (6) to demonstrate successful ONS of CN's through a thin layer of fascia placed over the nerve and prostate gland; and (7) to verify the experimentally determined therapeutic window for safe and reliable ONS without thermal damage to the CN's by comparison with a computational model for thermal damage. A 5.5-Watt Thulium fiber laser operated at 1870 nm and two pigtailed, single mode, near-IR diode lasers (150-mW, 1455-nm laser and 500-mW, 1550-nm laser) were used for non-contact stimulation of the rat CN's. Successful laser stimulation, as measured by an intracavernous pressure (ICP) response in the penis, was achieved with the laser operating in CW mode. CW optical nerve stimulation provides a significantly faster ICP response time using a lower laser power laser than conventional pulsed stimulation. An all-single-mode fiber design was successfully tested in a rat model. The CN reached a threshold temperature of ˜ 42 °C, with response times as short as 3 s, and ICP responses in the rat penis of up to 50 mmHg compared to a baseline of 5--10 mmHg. Chemical etching of the distal single-mode-fiber tip produced a concave shape and transformed the Gaussian to a flat-top spatial beam profile, resulting in simplified alignment of the laser beam with the nerve. This novel, all-single-mode-fiber laser nerve stimulation system introduces several advantages including: (1) a less expensive and more compact ONS configuration; (2) elimination of alignment and cleaning bulk optical components; and (3) improved spatial beam profile for simplified alignment. For the fascia layers over the CN's (240--600 microm), the 1550 nm laser with an optical penetration depth of ˜ 930 microm in water was substituted for the 1455 nm laser. Successful ONS was achieved, for the first time, in fascia layers up to 450 microm thick which is critical for future clinical translation of this method for intra-operative identification and preservation of CN's during prostate cancer surgery. In order to define the upper limit of the therapeutic window for ONS of CN in a rat model, in vivo, identification of the thermal damage threshold for the CN after laser irradiation was investigated by direct comparison of the visible thermal damage data with a theoretical thermal damage calculation utilizing a standard Arrhenius integral model.

Finite element simulation of the mechanism of laser ultrasound induced pain weapon

NASA Astrophysics Data System (ADS)

Zhou, Bo; Zhan, Ren Jun; Shan, Ning

2018-03-01

The Laser-Ultrasonic technique uses laser energy to generate ultrasound waves in various solids. In normal conditions, this technique is used to inspect large structures without destruction, but in military use, we hope get this destruction. Nociceptors in Human skin can feel cold, heat, mechanical and other stimuli, when the stimulus exceeds a certain threshold will produce pain. Based on this principle, a laser induced pain weapon may be made. The generated ultrasound wave form is affected by features of laser pulse. The results obtained from the finite element model of laser generated ultrasound are presented in terms of temperature and displacement. At first step, the transient temperature field can be precisely calculated by using the finite element method. Then, laser generated surface acoustic wave forms are calculated by coupling the temperature distribution. Displacement is used to represent the mechanical action of skin caused by laser ultrasound. Results from numerical simulation are compared with other references; the accuracy of the method is proved accordingly. The results of simulation in the given conditions demonstrate that the stresses generated by pulse laser in human skin model were about -8 and +4 MPa. According to the results of simulation, the max and min stress are both emerged in the range of 0 600 um, that is exactly the location of myelinated Aδ and unmyelinated C nociceptor. The value of stress is can be adjusted by chose suitable parameters of laser. The study provides a possibility for developing a new non-lethal weapon to control riots or crowd.

Treatment of neuropathic pain in a patient with diabetic neuropathy using transcutaneous electrical nerve stimulation applied to the skin of the lumbar region.

PubMed

Somers, D L; Somers, M F

1999-08-01

Diabetic neuropathy can produce severe pain. The purpose of this case report is to describe the alteration of pain in a patient with severe, painful diabetic neuropathy following application of transcutaneous electrical nerve stimulation (TENS) to the low back. The patient was a 73-year-old woman with pain in the left lower extremity over the lateral aspect of the hip and the entire leg below the knee. The pain prevented sound sleep. The intensity of pain was assessed with a visual analog scale. The TENS (80 Hz) was delivered 1 to 2 hours a day and during the entire night through electrodes placed on the lumbar area of the back. Following 20 minutes of TENS on the first day of treatment, the patient reported a 38% reduction in intensity of pain. After 17 days, the patient reported no pain following 20 minutes of TENS and that she could sleep through the night. Application of TENS to the skin of the lumbar area may be an effective treatment for the pain of diabetic neuropathy.

Experimental neck muscle pain impairs standing balance in humans.

PubMed

Vuillerme, Nicolas; Pinsault, Nicolas

2009-02-01

Impaired postural control has been reported in patients with chronic neck pain of both traumatic and non-traumatic etiologies, but whether painful stimulation of neck muscle per se can affect balance control during quiet standing in humans remains unclear. The purpose of the present experiment was thus to investigate the effect of experimental neck muscle pain on standing balance in young healthy adults. To achieve this goal, 16 male university students were asked to stand upright as still as possible on a force platform with their eyes closed in two conditions of No pain and Pain of the neck muscles elicited by experimental painful electrical stimulation. Postural control and postural performance were assessed by the displacements of the center of foot pressure (CoP) and of the center of mass (CoM), respectively. The results showed increased CoP and CoM displacements variance, range, mean velocity, and mean and median frequencies in the Pain relative to the No pain condition. The present findings emphasize the destabilizing effect of experimental neck muscle pain per se, and more largely stress the importance of intact neck neuromuscular function on standing balance.

Effect of shorter pulse duration in cochlear neural activation with an 810-nm near-infrared laser.

PubMed

Wang, Jingxuan; Tian, Lan; Lu, Jianren; Xia, Ming; Wei, Ying

2017-02-01

Optical neural stimulation in the cochlea has been presented as an alternative technique to the electrical stimulation due to its potential in spatially selectivity enhancement. So far, few studies have selected the near-infrared (NIR) laser in cochlear neural stimulation and limited optical parameter space has been examined. This paper focused on investigating the optical parameter effect on NIR stimulation of auditory neurons, especially under shorter pulse durations. The spiral ganglion neurons in the cochlea of deafened guinea pigs were stimulated with a pulsed 810-nm NIR laser in vivo. The laser radiation was delivered by an optical fiber and irradiated towards the modiolus. Optically evoked auditory brainstem responses (OABRs) with various optical parameters were recorded and investigated. The OABRs could be elicited with the cochlear deafened animals by using the 810-nm laser in a wide pulse duration ranged from 20 to 1000 μs. Results showed that the OABR intensity increased along with the increasing laser radiant exposure of limited range at each specific pulse duration. In addition, for the pulse durations from 20 to 300 μs, the OABR intensity increased monotonically along with the pulse duration broadening. While for pulse durations above 300 μs, the OABR intensity basically kept stable with the increasing pulse duration. The 810-nm NIR laser could be an effective stimulus in evoking the cochlear neuron response. Our experimental data provided evidence to optimize the pulse duration range, and the results suggested that the pulse durations from 20 to 300 μs could be the optimized range in cochlear neural activation with the 810-nm-wavelength laser.

SPF-RR sequential photothermal fractional resurfacing and remodeling with the variable pulse Er:YAG laser and scanner-assisted Nd:YAG laser.

PubMed

Marini, Leonardo

2009-12-01

Many different lasers, polychromatic high-intensity light sources (PCLs), and RF devices have claimed clinical efficacy in rejuvenating the skin. In this study, the sequential combination of two different laser wavelengths was evaluated to produce reliably significant clinical improvements optimizing treatment parameters. The left volar aspects of the forearms of four volunteers were treated with nine different parameter settings using a variable pulsewidth fractional Er:YAG 2940-nm laser with and without air cooling. The pain perception level was recorded on a 0-10 point scale (0=No pain; 10=Most severe pain). Three evaluations were made: during treatment, immediately after treatment, and 5 minutes after treatment. The same investigation was made on the right volar aspects of the same four volunteers using a short-pulse, random pattern, 3-mm spot, scanner-assisted Nd-YAG 1064-nm laser at 0.3 ms pulsewidth at seven different parameter settings. Clinical evaluations were made concerning erythema and edema 3 days after treatment, as well as pre-operative and 60 days postoperative skin texture plus color uniformity. Considering that the majority of cosmetic patients are willing to accept a relatively short and uneventful downtime (2-4 days according to a study we are presently conducting) and do prefer to limit their intra- and postoperative pain to a minimum, the best combination of clinical improvement matching these two important parameters were selected for our study. A treatment strategy combining two sequential passes of long-pulse Nd:YAG laser (Nd:YAG-LP) at 0.3 and 35 ms followed by two passes of long-pulse fractional Er:YAG laser (Er:YAG-FT) at 600 micros was designed to treat the facial regions of 10 volunteers affected by a combination of intrinsic (chrono-) and extrinsic (mostly photo-) aging. The pain perception level was recorded on a 0-10 scale (0=No pain; 10=Most severe pain). Three evaluations were made: during, immediately after, and 5 minutes after treatment. Erythema and edema were evaluated on a 0-3 point scale (0=No clinical signs; 3=Severe Clinical signs) at 7, 15 and 30 days. Improvements were determined by blind evaluation of photographs before, at 4 weeks, and at 8 weeks following treatments. Patient satisfaction was also evaluated on a 0-4 point scale (0=No satisfaction; 4=Excellent perceived improvement, 76-100%). At the 30-day follow-up, participants had clinically detectable improvements of facial telangiectasias (1-25%), lentigines (25-50%), diffuse dyspigmentation (25-75%), fine lines (25-75%), and skin texture (25-75%). Clinical improvements were maintained at the 60-day follow-up, demonstrating the prolonged photothermally induced biological effect on skin function and texture. All volunteers confirmed their willingness to undergo the same procedure again to maintain and possibly improve their clinical results. Further clinical evaluations at 4 and 6 months will therefore be needed to identify a suitably convenient interval between two consecutive procedures. The present study demonstrates objective and subjective improvements in fine lines, skin texture and dyspigmentation of facial skin after one sequential non-ablative and ablative laser treatment combining two different laser sources (Nd:YAG laser + Er:YAG laser).

Limits: The Keystone of Emotional Growth.

ERIC Educational Resources Information Center

Poarch, John E.

The concept of limits on child and teenage behavior is discussed in this book. Section I includes the core hypothesis of the theory of limits and discusses these essential concepts: (1) the pleasure/pain principle (the need to increase tolerance for stimulation in the pain center of the brain in order to be able to tolerate more stimulation in the…

Stress induces pain transition by potentiation of AMPA receptor phosphorylation.

PubMed

Li, Changsheng; Yang, Ya; Liu, Sufang; Fang, Huaqiang; Zhang, Yong; Furmanski, Orion; Skinner, John; Xing, Ying; Johns, Roger A; Huganir, Richard L; Tao, Feng

2014-10-08

Chronic postsurgical pain is a serious issue in clinical practice. After surgery, patients experience ongoing pain or become sensitive to incident, normally nonpainful stimulation. The intensity and duration of postsurgical pain vary. However, it is unclear how the transition from acute to chronic pain occurs. Here we showed that social defeat stress enhanced plantar incision-induced AMPA receptor GluA1 phosphorylation at the Ser831 site in the spinal cord and greatly prolonged plantar incision-induced pain. Interestingly, targeted mutation of the GluA1 phosphorylation site Ser831 significantly inhibited stress-induced prolongation of incisional pain. In addition, stress hormones enhanced GluA1 phosphorylation and AMPA receptor-mediated electrical activity in the spinal cord. Subthreshold stimulation induced spinal long-term potentiation in GluA1 phosphomimetic mutant mice, but not in wild-type mice. Therefore, spinal AMPA receptor phosphorylation contributes to the mechanisms underlying stress-induced pain transition. Copyright © 2014 the authors 0270-6474/14/3413737-10$15.00/0.

Can we "predict" long-term outcome for ambulatory transcutaneous electrical nerve stimulation in patients with chronic pain?

PubMed

Köke, Albère J; Smeets, Rob J E M; Perez, Roberto S; Kessels, Alphons; Winkens, Bjorn; van Kleef, Maarten; Patijn, Jacob

2015-03-01

Evidence for effectiveness of transcutaneous electrical nerve stimulation (TENS) is still inconclusive. As heterogeneity of chronic pain patients might be an important factor for this lack of efficacy, identifying factors for a successful long-term outcome is of great importance. A prospective study was performed to identify variables with potential predictive value for 2 outcome measures on long term (6 months); (1) continuation of TENS, and (2) a minimally clinical important pain reduction of ≥ 33%. At baseline, a set of risk factors including pain-related variables, psychological factors, and disability was measured. In a multiple logistic regression analysis, higher patient's expectations, neuropathic pain, no severe pain (< 80 mm visual analogue scale [VAS]) were independently related to long-term continuation of TENS. For the outcome "minimally clinical important pain reduction," the multiple logistic regression analysis indicated that no multisited pain (> 2 pain locations) and intermittent pain were positively and independently associated with a minimally clinical important pain reduction of ≥ 33%. The results showed that factors associated with a successful outcome in the long term are dependent on definition of successful outcome. © 2014 World Institute of Pain.

The efficacy of 95-Hz topical vibration in pain reduction for trigger finger injection: a placebo-controlled, prospective, randomized trial.

PubMed

Park, Kevin W; Boyer, Martin I; Calfee, Ryan P; Goldfarb, Charles A; Osei, Daniel A

2014-11-01

To determine whether vibratory stimulation would decrease pain experienced by patients during corticosteroid injection for trigger finger. A total of 90 trigger finger injections were randomized to 1 of 3 cohorts. With the injection, patients received no vibration (control group), ultrasound vibration (sham control group), or vibration (experimental group). We used a commercial handheld massaging device to provide a vibratory stimulus for the experimental group. We obtained visual analog scale (VAS) pain scores before and after injection to assess anticipated pain and actual pain experienced. Anticipated pain and actual pain did not differ significantly among groups. Anticipated VAS pain scores were 45, 48, and 50 and actual VAS pain scores were 56, 56, and 63 for the vibration, control, and sham control groups, respectively. When normalized using anchoring VAS pain scores for "stubbing a toe" or "paper cut," no between-group differences remained in injection pain scores. Concomitant vibratory stimulation does not reduce pain experienced during corticosteroid injections for trigger finger. Therapeutic I. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Implementation fidelity of self-administered transcutaneous electrical nerve stimulation (TENS) in patients with chronic back pain: an observational study.

PubMed

Pallett, Edward J; Rentowl, Patricia; Johnson, Mark I; Watson, Paul J

2014-03-01

The efficacy of transcutaneous electrical nerve stimulation (TENS) for pain relief has not been reliably established. Inconclusive findings could be due to inadequate TENS delivery and inappropriate outcome assessment. Electronic monitoring devices were used to determine patient compliance with a TENS intervention and outcome assessment protocol, to record pain scores before, during, and after TENS, and measure electrical output settings. Patients with chronic back pain consented to use TENS daily for 2 weeks and to report pain scores before, during, and after 1-hour treatments. A ≥ 30% reduction in pain scores was used to classify participants as TENS responders. Electronic monitoring devices "TLOG" and "TSCORE" recorded time and duration of TENS use, electrical settings, and pain scores. Forty-two patients consented to participate. One of 35 (3%) patients adhered completely to the TENS use and pain score reporting protocol. Fourteen of 33 (42%) were TENS responders according to electronic pain score data. Analgesia onset occurred within 30 to 60 minutes for 13/14 (93%) responders. It was not possible to correlate TENS amplitude, frequency, or pulse width measurements with therapeutic response. Findings from TENS research studies depend on the timing of outcome assessment; pain should be recorded during stimulation. TENS device sophistication might be an issue and parameter restriction should be considered. Careful protocol design is required to improve adherence and monitoring is necessary to evaluate the validity of findings. This observational study provides objective evidence to support concerns about poor implementation fidelity in TENS research.

Light Irradiation And Response Of The Living Body - Effect Of Pain Relief And Promotion Of Wound Healing -

NASA Astrophysics Data System (ADS)

Taguchi, Yoshio; Kurokawa, Yoshimochi; Ohara, Itaru; Ueki, Hamaichi; Inaba, Humio

1989-09-01

The first report of laser irradiation for wound healing was done by Mester, E., et al. in 1968. From their reports, we can get many knowledges and suggestions as for laser irradiation. At that time he used ruby laser (694.3 nm wave length) for surgical wounds and burns on the back skin of mice. The condition of irradiation was studied with energy density between 0.5-10 J/cm2 twice a week. As a result, they noticed 1 J/cm2 irradiation was effective for those wounds. After a few experimental reports, they published their clinical studies in 1975. Clinically, they used He-Ne laser (632.8 nm wave length) irradiation. Human leg ulcers due to peripheral circulatory disturbance were treated with energy density of 4 J/cm2 twice a week. And they got good results, obtaining complete healing in two-thirds of the cases. We became strongly stimulated by those reports. We have been studying the effect of light on experimental and clinical wound healing as well as on various kinds of biological phenomena since 1980. Particularly, its effect according to the difference of light has been studied. In October 1982, the first clinical case was tried by Argon laser (514.5 nm wave length) irradiation for therapeutic purpose. A man had a chronic ulcer of the left first toe due to Buerger's disease for 5 months. Surprizingly, on the 14th day after 6 treatments of the light irradiation, his ulcer completely healed. During these treatments, the patient noticed that the pain completely disappeared after 2 treatments. Fifty Argon laser treatments were carried out on clinical cases after these experiences, we reached to a conclusion that light irradiation stimulated something in the injured tissues and lead to good clinical results. Several studies concerning mechanism for these effects i.e. peripheral circulation, histology of granulation, cell proliferation, chemistry and other studies were carried out. From these investigations, peripheral circulation was improved when in those who were suffering from vascular disorders but was not effective in normal subjects. From a study of cellular electrophoretic mobility, irradiated G0G1 cells increased their mobility, but irradiated G2M cells decreased. These results suggested light irradiation contributed to homeostasis of living cells, tissues, and body. Experiments concerning the light sources, i.e. wave length, energy density and polarization were done. As a result, linear polarization and right circular polarization improved wound healing, but incoherent light itself did not. ,According to our studies, no distinguished differences among various kinds of wave length were noticed. And light irradiation with energy density was very effective between 2 to 6 J/cm2. We strongly suggest the role of coherency is very important to do light irradiation on the living body. In conclusion, we like to propose our new viewpoint. That is, the light irradiation should be discussed with the structure of high molecular substances in the living body.

Proximal and distal esophageal sensitivity is decreased in patients with Barrett’s esophagus

PubMed Central

Krarup, Anne L; Olesen, Søren S; Funch-Jensen, Peter; Gregersen, Hans; Drewes, Asbjørn M

2011-01-01

AIM: To investigate sensations to multimodal pain stimulation in the metaplastic and normal parts of the esophagus in patients with Barrett’s esophagus (BE). METHODS: Fifteen patients with BE and 15 age-matched healthy volunteers were subjected to mechanical, thermal and electrical pain stimuli of the esophagus. Both the metaplastic part and the normal part (4 and 14 cm, respectively, above the esophago-gastric junction) were examined. At sensory thresholds the stimulation intensity, referred pain areas, and evoked brain potentials were recorded. RESULTS: Patients were hyposensitive to heat stimulation both in the metaplastic part [median stimulation time to reach the pain detection threshold: 15 (12-34) s vs 14 (6-23) s in controls; F = 4.5, P = 0.04] and the normal part of the esophagus [median 17 (6-32) s vs 13 (8-20) s in controls; F = 6.2, P = 0.02]. Furthermore, patients were hyposensitive in the metaplastic part of the esophagus to mechanical distension [median volume at moderate pain: 50 (20-50) mL vs 33 (13-50) mL in controls; F = 5.7, P = 0.02]. No indication of central nervous system abnormalities was present, as responses were comparable between groups to electrical pain stimuli in the metaplastic part [median current evoking moderate pain: 13 (6-26) mA vs 12 (9-24) mA in controls; F = 0.1, P = 0.7], and in the normal part of the esophagus [median current evoking moderate pain: 9 (6-16) mA, vs 11 (5-11) mA in controls; F = 3.4, P = 0.07]. Furthermore, no differences were seen for the referred pain areas (P-values all > 0.3) or latencies and amplitudes for the evoked brain potentials (P-values all > 0.1). CONCLUSION: Patients with BE are hyposensitive both in the metaplastic and normal part of esophagus likely as a result of abnormalities affecting peripheral nerve pathways. PMID:21274382

Effect of low-level laser therapy on the post-surgical inflammatory process after third molar removal: study protocol for a double-blind randomized controlled trial.

PubMed

Oliveira Sierra, Simone; Melo Deana, Alessandro; Mesquita Ferrari, Raquel Agnelli; Maia Albarello, Priscilla; Bussadori, Sandra Kalil; Santos Fernandes, Kristianne Porta

2013-11-06

Low-level laser therapy (LLLT) has been shown to modulate the inflammatory process without adverse effects , by reducing pain and swelling and promoting the repair of damaged tissues. Because pain, swelling and muscle spasm are complications found in virtually all patients following oral surgery for the removal of impacted teeth, this model has been widely used to evaluate the effects of LLLT on the inflammatory process involving bone and, connective tissue and the muscles involved in mastication. After meeting the eligibility criteria, 60 patients treated at a Specialty Dental Center for the removal of impacted lower third molars will be randomly divided into five groups according to the type of laser therapy used at the end of surgery (intraoral irradiation with 660 nm laser; extraoral irradiation with 660 nm laser; intraoral irradiation with 808 nm laser; extraoral irradiation with 808 nm laser and no irradiation). To ensure that patients are blinded to the type of treatment they are receiving, the hand piece of the laser apparatus will be applied both intraorally and extraorally to all participants, but the device will be turned on only at the appropriate time, as determined by the randomization process. At 2 and 7 days after surgery, the patients will be evaluated by three blinded evaluators who will measure of swelling, mouth opening (muscle spasm evaluation) and pain (using two different pain scales). The 14-item Oral Health Impact Profile (OHIP-14) will be used to assess QOL. All data will be analyzed with respect to the normality of distribution using the Shapiro-Wilk test. Statistically significant differences between the experimental groups will be determined using analysis of variance, followed by a suitable post hoc test, when necessary. The significance level will be set at α = 0.05. The lack of standardization in studies with regard to the samples, methods and LLLT parameters complicates the determination of the actual effect of laser therapy on this model. The present study aims to provide a randomized, controlled, double-blind trial to compare four different LLLT parameters in relation to the outcomes of pain, swelling and muscle spasm following surgery for the extraction of impacted third molars and evaluate the effects os surgery on patients' quality os life (QOL). Brazilian Registry of Clinical Trials - Rebec (RBR-6XSB5H).

Evoked potentials after painful cutaneous electrical stimulation depict pain relief during a conditioned pain modulation.

PubMed

Höffken, Oliver; Özgül, Özüm S; Enax-Krumova, Elena K; Tegenthoff, Martin; Maier, Christoph

2017-08-29

Conditioned pain modulation (CPM) evaluates the pain modulating effect of a noxious conditioning stimulus (CS) on another noxious test stimulus (TS), mostly based solely on subjective pain ratings. We used painful cutaneous electrical stimulation (PCES) to induce TS in a novel CPM-model. Additionally, to evaluate a more objective parameter, we recorded the corresponding changes of cortical evoked potentials (PCES-EP). We examined the CPM-effect in 17 healthy subjects in a randomized controlled cross-over design during immersion of the non-dominant hand into 10 °C or 24 °C cold water (CS). Using three custom-built concentric surface electrodes, electrical stimuli were applied on the dominant hand, inducing pain of 40-60 on NRS 0-100 (TS). At baseline, during and after CS we assessed the electrically induced pain intensity and electrically evoked potentials recorded over the central electrode (Cz). Only in the 10 °C-condition, both pain (52.6 ± 4.4 (baseline) vs. 30.3 ± 12.5 (during CS)) and amplitudes of PCES-EP (42.1 ± 13.4 μV (baseline) vs. 28.7 ± 10.5 μV (during CS)) attenuated during CS and recovered there after (all p < 0.001). In the 10 °C-condition changes of subjective pain ratings during electrical stimulation and amplitudes of PCES-EP correlated significantly with each other (r = 0.5) and with CS pain intensity (r = 0.5). PCES-EPs are a quantitative measure of pain relief, as changes in the electrophysiological response are paralleled by a consistent decrease in subjective pain ratings. This novel CPM paradigm is a feasible method, which could help to evaluate the function of the endogenous pain modulation processes. German Clinical Trials Register DRKS-ID: DRKS00012779 , retrospectively registered on 24 July 2017.

Feasibility, safety, and effectiveness of transcranial direct current stimulation for decreasing post-ERCP pain: a randomized, sham-controlled, pilot study.

PubMed

Borckardt, Jeffrey J; Romagnuolo, Joseph; Reeves, Scott T; Madan, Alok; Frohman, Heather; Beam, Will; George, Mark S

2011-06-01

Emerging evidence shows that transcranial direct current stimulation (tDCS), a minimally invasive brain stimulation technique, has analgesic effects in chronic pain patients and in healthy volunteers with experimental pain. No studies have examined the analgesic effects of tDCS immediately after surgical/endoscopic procedures. Endoscopy investigating abdominal pain, especially ERCP, can cause significant postprocedural pain. To test the feasibility, efficacy, and safety of tDCS on post-ERCP pain and analgesia use. Randomized, sham-controlled, pilot study. Tertiary-care medical center. This study involved 21 patients who were hospitalized overnight for ERCP for unexplained right upper quadrant pain. Twenty minutes of real 2.0 mA tDCS or sham (anode over left prefrontal cortex; cathode over gut-representation of right sensory cortex) immediately after ERCP. Pain (visual analogue scale, McGill pain questionnaire, brief pain inventory), patient-controlled analgesia use, adverse events. Real tDCS was associated with 22% less total hydromorphone use, versus sham. The slope of the cumulative patient-controlled analgesia usage curve was significantly steeper in the sham tDCS group (F [2,13] = 15.96; P = .0003). Real tDCS patients reported significantly less pain interference with sleep (t [17] = 3.70; P = .002) and less throbbing pain (t [16] = 2.37; P = .03). Visual analogue scale pain and mood scores (4 hours post-ERCP) suggested a nonsignificant advantage for real tDCS, despite less hydromorphone use. Side effects of tDCS were limited to mild, self-limited tingling, itching, and stinging under electrodes. Small sample size, variability in chronic pain, and chronic opioid use. In this pilot study, tDCS appears to be safe, has minimal side effects, and may reduce postprocedural analgesia requirements and subjective pain ratings. Future studies appear warranted. Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Conversion of the luminescence of laser dyes in opal matrices to stimulated emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alimov, O K; Basiev, T T; Orlovskii, Yu V

The luminescence and laser characteristics of a synthetic opal matrix filled with organic dyes are studied upon excitation by nanosecond laser pulses. The appearance of stimulated emission in a partially ordered scattering medium is investigated. It is shown that if the luminescence spectrum of a dye (oxazine-17) is located far outside the photonic bandgap of the opal matrix, stimulated emission along a preferential direction in the (111) plane is observed when pumping exceeds a threshold even without an external optical cavity. The stimulated emission spectrum is considerably narrower than the luminescence spectrum and consists of several narrow lines located withinmore » the dye luminescence band. If the luminescence spectrum of a dye (rhodamine 6G) overlaps with the photonic bandgap of the opal matrix, a different picture is observed. The loss of radiation in the matrix leads to the red shift of the luminescence spectrum, while the stimulated emission as in the case of oxazine-17 lies is observed within the luminescence band. (active media, lasers, and amplifiers)« less

Continuous-wave optical stimulation of the rat prostate nerves using an all-single-mode 1455 nm diode laser and fiber system

NASA Astrophysics Data System (ADS)

Tozburun, Serhat; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2011-03-01

Optical nerve stimulation (ONS) has recently been reported as a potential alternative to electrical nerve stimulation. Continuous-wave (CW) laser stimulation of the prostate cavernous nerves (CN) in a rat model, in vivo, has also been demonstrated in our previous studies. The objective of this study is to present a new all-single-mode-fiber configuration for ONS with the laser operating in CW mode for potential diagnostic applications. An infrared pigtailed single-mode diode laser (λ = 1455 nm) was used in this study for noncontact ONS. This new all-fiber approach introduces several advantages including: (1) a less expensive and more compact ONS system, (2) elimination of alignment of optical components, and (3) an improved spatial beam profile. Successful optical stimulation of the rat CN using this new design was observed after the CN reached a threshold temperature of ~ 41 °C with response times as short as 3 s. Upon further study, this configuration may be useful for identification and preservation of the cavernous nerves during prostate cancer surgery.

Real efficiency of ambulatory laser treatment at the patients with different rheumatic diseases

NASA Astrophysics Data System (ADS)

Sidenco, Elena-Luminita; Ristache, Sanda; Belu, Luminita

2001-06-01

We consulted 189 patients, with different locomotory diseases: degenerative, posttraumatic and chronic inflammatory rheumatic diseases. We followed the main clinical parameters: pain, limitation of mobility, affected function, inflammation and disorders of sensitivity. We applied an infrared LASER source of 100 mW (BTL), daily, for 5 days. The tolerance of the patients at the LASER treatment was excellent (100%). The evolution of the clinical parameters was variated, but inflammation, limitation of mobility and the affected function significantly improved (30-50%). We found a significant diminution of pain (27- 39%). We believe the LASER treatment in ambulatory conditions is essential for the function of the patients with different locomotory diseases.

Transverse tripolar spinal cord stimulation: results of an international multicenter study.

PubMed

Oakley, John C; Espinosa, Francisco; Bothe, Hans; McKean, John; Allen, Peter; Burchiel, Kim; Quartey, Gilbert; Spincemaille, Geert; Nuttin, Bart; Gielen, Frans; King, Gary; Holsheimer, Jan

2006-07-01

Experienced neurosurgeons at eight spinal cord stimulation centers in the United States, Canada, and Europe participated in a study from 1997 to 2000 investigating the safety, performance, and efficacy of a Transverse Tripolar Stimulation (TTS) system invented at the University of Twente, the Netherlands. This device was proposed to improve the ability of spinal cord stimulation to adequately overlap paresthesia to perceived areas of pain. Fifty-six patients with chronic, intractable neuropathic pain of the trunk and/or limbs more than three months' duration (average 105 months) were enrolled with follow-up periods at 4, 12, 26, and 52 weeks. All patients had a new paddle-type lead implanted with four electrodes, three of them aligned in a row perpendicular to the cord. Fifteen of these patients did not undergo permanent implantation. Of the 41 patients internalized, 20 patients chose conventional programming using an implanted pulse generator to drive four electrodes, while 21 patients chose a tripole stimulation system, which used radiofrequency power and signal transmission and an implanted dual-channel receiver to drive three electrodes using simultaneous pulses of independently variable amplitude. On average, the visual analog scale scores dropped more for patients with TTS systems (32%) than for conventional polarity systems (16%). Conventional polarity systems were using higher frequencies on average, while usage range was similar. Most impressive was the well-controlled "steering" of the paresthesias according to the dermatomal topography of the dorsal columns when using the TTS-balanced pulse driver. The most common complication was lead migration. While the transverse stimulation system produced acceptable outcomes for overall pain relief, an analysis of individual pain patterns suggests that it behaves like spinal cord stimulation in general with the best control of extremity neuropathic pain. This transverse tripole lead and driving system introduced the concept of electrical field steering by selective recruitment of axonal nerve fiber tracts in the dorsal columns.

Stimulation of the human auditory nerve with optical radiation

NASA Astrophysics Data System (ADS)

Fishman, Andrew; Winkler, Piotr; Mierzwinski, Jozef; Beuth, Wojciech; Izzo Matic, Agnella; Siedlecki, Zygmunt; Teudt, Ingo; Maier, Hannes; Richter, Claus-Peter

2009-02-01

A novel, spatially selective method to stimulate cranial nerves has been proposed: contact free stimulation with optical radiation. The radiation source is an infrared pulsed laser. The Case Report is the first report ever that shows that optical stimulation of the auditory nerve is possible in the human. The ethical approach to conduct any measurements or tests in humans requires efficacy and safety studies in animals, which have been conducted in gerbils. This report represents the first step in a translational research project to initiate a paradigm shift in neural interfaces. A patient was selected who required surgical removal of a large meningioma angiomatum WHO I by a planned transcochlear approach. Prior to cochlear ablation by drilling and subsequent tumor resection, the cochlear nerve was stimulated with a pulsed infrared laser at low radiation energies. Stimulation with optical radiation evoked compound action potentials from the human auditory nerve. Stimulation of the auditory nerve with infrared laser pulses is possible in the human inner ear. The finding is an important step for translating results from animal experiments to human and furthers the development of a novel interface that uses optical radiation to stimulate neurons. Additional measurements are required to optimize the stimulation parameters.

Mechanisms of Corneal Pain and Implications for Postoperative Pain After Laser Correction of Refractive Errors.

PubMed

Garcia, Renato; de Andrade, Daniel C; Teixeira, Manoel J; Nozaki, Siro S; Bechara, Samir J

2016-05-01

The cornea is the target of most surgeries for refractive disorders, as myopia. It is estimated that almost 1 million patients undergo corneal refractive surgery each year in the United States. Refractive surgery includes photorefractive keratectomy (PRK) that produces intense postoperative pain. This review presents the main pain mechanisms behind PRK-related pain and the available therapeutic options for its management. Data sources included literature of cornea anatomy, treatment of PRK postoperative pain, mechanisms of corneal pain, in 3 electronic databases: Pubmed, Scopus, and Web of Science. Only double-blinded controlled trials on pain control after PRK were selected to show the endpoints, treatment, and control strategies. A total of 18 double-blind, controlled trials were identified. These studies have shown the use of topical nonsteroidal anti-inflammatory drugs, topical steroidal anti-inflammatory drugs, systemic analgesics, cold balanced saline solution, topical anesthetic, gabapentin, and morphine to treat postoperative pain in PRK. The percentage of responders has seldom been reported, and few studies allow for the formal calculation of the number necessary to treat. Postoperative intense pain after PRK laser surgery remains the main challenge to its widespread use for the correction of refractive errors.

Spinal cord stimulation for chronic pain.

PubMed

Mailis-Gagnon, A; Furlan, A D; Sandoval, J A; Taylor, R

2004-01-01

Spinal cord stimulation (SCS) is a form of therapy used to treat certain types of chronic pain. It involves an electrical generator that delivers pulses to a targeted spinal cord area. The leads can be implanted by laminectomy or percutaneously and the source of power is supplied by an implanted battery or by an external radio-frequency transmitter. The exact mechanism of action of SCS is poorly understood. To assess the efficacy and effectiveness of spinal cord stimulation in relieving certain kinds of pain, as well as the complications and adverse effects of this procedure. We searched MEDLINE and EMBASE to September 2003; the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 3, 2003); textbooks and reference lists in retrieved articles. We also contacted experts in the field of pain and the main manufacturer of the stimulators. We included trials with a control group, either randomized controlled trials (RCTs) or non-randomized controlled clinical trials (CCTs), that assessed spinal cord stimulation for chronic pain. Two independent reviewers selected the studies, assessed study quality and extracted the data. One of the assessors of methodological quality was blinded to authors, dates and journals. The data were analysed using qualitative methods (best evidence synthesis). Two RCTs (81 patients in total) met our inclusion criteria. One was judged as being of high quality (score of 3 on Jadad scale) and the other of low quality (score of 1 on Jadad scale). One trial included patients with Complex Regional Pain Syndrome Type I (reflex sympathetic dystrophy) and the other patients with Failed Back Surgery Syndrome. The follow-up periods varied from 6 to 12 months. Both studies reported that SCS was effective, however, meta-analysis was not undertaken because of the small number of patients and the heterogeneity of the study population. Although there is limited evidence in favour of SCS for Failed Back Surgery Syndrome and Complex Regional Pain Syndrome Type I, more trials are needed to confirm whether SCS is an effective treatment for certain types of chronic pain. In addition, there needs to be a debate about trial designs that will provide the best evidence for assessing this type of intervention.