Article

Effect of 850 nm He-Ne Laser Therapy on Nerve Conduction and Foot Planter Pressures Distribution of Painful Diabetic Neuropathy: A Randomized Controlled Trial

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Abstract

Introduction: Diabetic neuropathy patients are at very high risk for developing foot ulcer that may lead to lower extremity amputation and threaten the patient’s life. Objective: To evaluate the effects of scanning 850 nm He-Ne infrared laser on nerve conduction, pain intensity, and foot planter pressure distribution of painful diabetic polyneuropathy patients. Methods: Thirty diabetic neuropathy patients with pain and reduced nerve conduction velocity were randomly divided into two groups; an experimental group (active laser group, n=15) and a control group (placebo laser group, n=15). Peak static and dynamic planter pressure were measured under heel, big toe and little toe. Sural and Peroneal nerves conduction velocity and amplitude and pain level were measured before and after treatment in both groups. The active laser group had got scanning 850 nm He–Ne infrared laser on foot planter surface and lumbosacral area with 5.7 J/cm2 for 15 min/site/session, 3 session /week for four weeks. Results: All measured parameters improved significantly in the active laser group, while no significant changes obtained in the control group. Comparison of post treatment measurements between groups showed that sural nerve conduction velocity and amplitude, pain level, and peak static and dynamic planter pressure were significantly higher in the experimental group compared with the control group. On the other hand there was no significant difference between groups for peroneal nerve conduction velocity and amplitude. Conclusion: 850 nm He–Ne therapy with the applied parameter and technique was an effective modality for improving nerve conduction, redistributing foot plantar pressures and relieving pain of painful diabetic polyneuropathy patients.

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... tumors and thyroid dysfunctions), pregnancy, metallic implantation, drug abuse, and a TRNCSS total score <5. 4,7,8,27,28 Treatment Equipment 1-BEMER mattress: BEMER International AG (Liechtenstein) mattress product was used for producing magnetic therapy. The maximum average flux density (intensity) of BEMER on its highest output level is 150 microtesla (μT). ...
... The proximal stimulation was applied just below the head of the fibula while the recording electrode was applied over the Extensor Digitorum Brevis to get a supra-maximal stimulus. 4,22,27 2. Sural nerve conduction velocity: It was investigated by putting an active pick-up electrode posterior and below the lateral malleolus. The reference electrode was put at 3 cm distal to the active electrode and the ground electrode was put between the cathode of the stimulator and the active pickup electrode. ...
... Stimulation was applied slightly lateral to the midline in the lower third of the posterior aspects of the leg with the cathode distally about 17 cm from the active electrode (10-14 cm). 4,8,22,27 c. Neuropathy Severity It was also evaluated by the TRCNSS which is an objective method to detect the presence and intensity of DPN. ...
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Transcutaneous oxygen, laser Doppler flowmetry, peroneal nerve motor conduction velocity and skin temperature were assessed in both legs of 34 diabetic patients, who had a mean age of 41 (range 29-77) years, and diabetes duration of 21 (3-34) years. Transcutaneous oxygen significantly correlated with peroneal nerve motor conduction velocity (r = 0.59 p < 0.001) and laser Doppler flowmetry (r = 0.7 p < 0.001). Laser Doppler flowmetry correlated weakly with peroneal motor conduction velocity, (r = 0.34 p < 0.05). In each patient the leg with the higher transcutaneous oxygen (mean 70.2 +/- 9.3 (SD) mmHg) had a significantly higher peroneal motor conduction velocity (45.3 +/- 7.1 vs 41.5 +/- 6.3 m/s, p < 0.01), than the leg with the lower transcutaneous oxygen (61.0 +/- 11.9 mmHg), though no difference in skin temperature was observed, 31.4 +/- 0.4 vs 31.1 +/- 0.5 degrees C. We then assessed the potential for reversibility of conduction velocity deficits in ten non-diabetic patients, aged 59 (52-77) years, undergoing unilateral femoro-popliteal bypass, measuring transcutaneous oxygen, peroneal nerve motor conduction velocity and skin temperature pre- and 6 weeks post-surgery. In the control leg (unoperated) there was no significant change in transcutaneous oxygen (63.2 +/- 8.8 vs 63.0 +/- 4.6 mm Hg), peroneal nerve motor conduction velocity (45.1 +/- 7.8 vs 43.4 +/- 7.2 m/s) or skin temperature (30.8 +/- 1.3 vs 30.2 +/- 1.2 degrees C) after surgery (all NS).(ABSTRACT TRUNCATED AT 250 WORDS)
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The effects of laser light on the immune system have not been extensively characterized. Low-power laser sources, such as the helium-neon (He-Ne) laser with a wavelength of 632.8 nm, have been found to produce photobiological effects with evidence of interference with immunological functions. We have investigated the effects of He-Ne laser irradiation on Ficoll-Hypaque-isolated human peripheral blood mononuclear cells (PBMC). Cultured cells were irradiated for various times at two selected intensities and then stimulated with different mitogens. The rate of incorporation of 3H-thymidine into the DNA of stimulated cells decreased with increasing energy density. The levels of interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in supernatants of the cultures were determined (irradiated either before or after stimulation). When stimulating cells after irradiation, significantly increased levels of all cytokines were detected after 30 min of irradiation (18.9 J cm-2), whereas after 60 min of irradiation (37.8 J cm-2) cytokine levels were found to be significantly decreased.
Article
Foot ulceration results in substantial morbidity amongst diabetic patients. We have studied prospectively the relationship between high foot pressures and foot ulceration using an optical pedobarograph. A series of 86 diabetic patients, mean age 53.3 (range 17-77) years, mean duration of diabetes 17.1 (range 1-36) years, were followed-up for a mean period of 30 (range 15-34) months. Clinical neuropathy was present in 58 (67%) patients at baseline examination. Mean peak foot pressure was higher at the follow-up compared to baseline (13.5 kg.cm-2 +/- 7.1 SD vs 11.2 +/- 5.4, p less than 0.001) with abnormally high foot pressures (greater than 12.3) being present in 55 patients at follow-up and 43 at the baseline visit (p = NS). Plantar foot ulcers developed in 21 feet of 15 patients (17%), all of whom had abnormally high pressures at baseline; neuropathy was present in 14 patients at baseline. Non-plantar ulcers occurred in 8 (9%) patients. Thus, plantar ulceration occurred in 35% of diabetic patients with high foot pressures but in none of those with normal pressures. We have shown for the first time in a prospective study that high plantar foot pressures in diabetic patients are strongly predictive of subsequent plantar ulceration, especially in the presence of neuropathy.
Article
The morphological findings in sural nerve biopsy specimens from 15 diabetic patients with mild neuropathy were compared with control biopsies from eight non-neuropathic, non-diabetic subjects, and correlations were sought with electrophysiological studies and quantitative sensory tests for vibration, thermal, and current perception thresholds. Myelinated fibre density was reduced compared with control biopsies (4042 +/- 2090 (+/- SD) vs 6800 +/- 1100 mm-2; p less than 0.01). A strong correlation existed between myelinated fibre density and sural sensory conduction velocity (r = 0.84, p less than 0.001), sural action potential amplitude (r = 0.74, p less than 0.001), peroneal motor conduction velocity (r = 0.58, p less than 0.02), and median sensory amplitude (r = 0.64, p less than 0.01) but there was no correlation between myelinated fibre density and any quantitative sensory test. We conclude that conventional electrophysiological tests in the lower limb are reliable surrogate measures for structural abnormalities in early diabetic neuropathy.
Article
The assessment of a measure of chronic pain, should be reliable, valid and sensitive to change. Our study evaluated the reliability of 3 pain scales, visual analogue scale (VAS), numerical rating scale (NRS) and verbal rating scale (VRS) in literate and illiterate patients with rheumatoid arthritis (RA). Patients with RA attending an outpatient rheumatology clinic were interviewed and asked to score their pain levels on the 3 pain scales. The scales were presented in random order, twice, before and just after a regular medical consultation. Ninety-one patients were studied (25 illiterate and 66 literate). The Pearson product moment correlation between first and second assessment was 0.937 for VAS, 0.963 for NRS and 0.901 for VRS in the literate patient group and 0.712 for VAS, 0.947 for NRS and 0.820 for VRS in the illiterate patient group. These results indicate that the NRS has the higher reliability in both groups of patients.
Article
The authors suggest that, on clinical grounds, the pain occurring in peripheral neuropathies may arise either from normal endings in the nerve trunk (nerve trunk pain) or from abnormally excitable damaged and regenerating nociceptor neurites (dysesthetic pain). A commonplace example illustrates the distinction. Pain occurs with rupture of a lower lumbar intervertebral disk and consequent compression of, ordinarily, an L-5 or S-1 root. The most prominent feature, characteristic of nerve trunk pain, is the deep aching low back pain extending along the course of the sciatic nerve trunk, often with palpable tenderness ('sciatica' in older parlance). The effects of rest in an optimal position and of nerve stretch (straight leg raising) are well known to every physician. Some dysesthetic pain may also occur, along with nonpainful dysesthesias and hypesthesia, in the dermatomal distribution of L-5 or S-1. Our point is that dysesthetic pain, nerve trunk pain, or both may be present in peripheral neuropathy.
Article
Ga-Al-As laser irradiation (830 nm wavelength) inhibits the action potentials in the dorsal roots elicited from the saphenous nerve of the rat. Following laser irradiation to the saphenous nerve, the amplitude of slower conduction parts of action potentials (conduction velocity < 12 m/s) were suppressed. This suppression was irradiation time dependent. After 3 min irradiation, slowest conduction velocity group (< 1.3 m/s) were totally diminished and 1.3-12 m/s group were reduced to 12-67%. In contrast, faster component (> 12 m/s) was unaffected by laser irradiation. These findings suggest that laser irradiation may selectively target fibers conducting at slow velocities which include afferent axons from nociceptors.
Article
Schwann cell proliferation is considered an essential part of Wallerian degeneration after nerve damage. Laminin, an important component of the extracellular matrix and produced by Schwann cells, provides a preferred substrate for outgrowing axons. To study whether low energy (He-Ne) laser irradiation may exert a positive effect on nerve regeneration through an effect on Schwann cells, its effect was evaluated in vivo. Schwann cells were isolated from sciatic nerves of 4-5-day-old Wistar rates and cultured on 96-multiwell plates. The cells were irradiated by a He-Ne laser beam (632.8 nm, 5.98 mW) that was optically expanded to a beam width of 4 mm. During irradiation the plate was kept in an air-tight box equilibrated with humidified air containing 5% CO2 and kept at 37 degrees C. At three consecutive days, starting either at day 5 or day 8, cells were irradiated each day for 0.5, 1, 2, 5 or 10 min. Both cell number and laminin production were determined for each irradiation condition (n = 5) within one experiment. Schwann cells that were irradiated from day 8 on were hardly affected by laser irradiation. However, the proliferation of cells that were irradiated starting on day 5 was significantly increased after 1, 2, and 5 min of daily irradiation, compared to non-irradiated control cultures. The laminin production per cell of these Schwann cells was not significantly altered. From these results we conclude that He-Ne laser irradiation can modulate proliferation of rat Schwann cells in vitro in a dose-dependent manner.
Article
An animal study is presented examining the effect of low level laser (LLL) treatment on nerve regeneration following axonotmesis. Twenty animals received a standardised injury to the right sciatic nerve using a time, load and length sequence (10 min, 150 N, 5 mm) known to cause extensive axonal degeneration of the rat sciatic nerve. The LLL treatment was administered using a hand-held laser probe in light contact with the skin on the dorsal aspect of the hind leg overlying the site of the axonotmesis injury to the sciatic nerve. A group of 10 animals were treated with 6J of LLL (GaAlAs 830 nm) daily for a period of 28 d. Ten more animals were treated daily with a sham exposure setting and served as controls. Nerve function was assessed by a recognised method of walking tract print analysis; the "Sciatic Functional Index" (SFI), and nerve regeneration was assessed by recording the evoked compound action potentials (cAP) in the common peroneal nerve. At 21 d post-injury, the laser-treated group had a significantly lower median SFI than the sham laser-treated group, indicating that the real laser treatment had improved functional recovery in the nerve. However, no differences were found between the evoked cAP parameters that were measured in the laser-treated and sham laser-treated groups. Histological examination reiterated the lack of difference between the two groups. Consequently, the effects of LLL on recovery must have occurred more peripherally to the point measured.
Article
Agreement between two methods of clinical measurement can be quantified using the differences between observations made using the two methods on the same subjects. The 95% limits of agreement, estimated by mean difference +/- 1.96 standard deviation of the differences, provide an interval within which 95% of differences between measurements by the two methods are expected to lie. We describe how graphical methods can be used to investigate the assumptions of the method and we also give confidence intervals. We extend the basic approach to data where there is a relationship between difference and magnitude, both with a simple logarithmic transformation approach and a new, more general, regression approach. We discuss the importance of the repeatability of each method separately and compare an estimate of this to the limits of agreement. We extend the limits of agreement approach to data with repeated measurements, proposing new estimates for equal numbers of replicates by each method on each subject, for unequal numbers of replicates, and for replicated data collected in pairs, where the underlying value of the quantity being measured is changing. Finally, we describe a nonparametric approach to comparing methods.
Article
Measurements of plantar pressure provide an indication of foot and ankle function during gait and other functional activities, because the foot and ankle provide both the necessary support and flexibility for weight bearing and weight shifting while pet-forming these activities.(1-3) Although plantar pressure data have been recognized as an important element in the assessment of clients with diabetes and peripheral neuropathy, information derived from plantar pressure data also can assist in determining and managing the impairments associated with various musculoskeletal, integumentary, and neurological disorders. The use of force platforms is the method most commonly used to assess the interaction of the foot and the supporting surface. Although the force platform provides valuable information regarding both the vertical and shear components of the ground reaction force, it provides little information on how the plantar surface of the foot is loaded with respect to the supporting surface. When evaluating patients, atypical amounts of loading or patterns of loading may be reflective of a systemic or localized lower-extremity pathology and may be indicators (risk factors) for or predictors of further pathology or worsening of the existing pathology.(4) In addition, force platforms have very specific requirements for attachment to the supporting surface on which data collection will occur. Such is not the case with numerous commercially available systems for measuring plantar pressure (eg, Emed sensor platform,* Pedar insole system,* F-Scan system,(dagger) Musgrave footprint system double dagger). Thus, plantar pressure measurement systems offer the clinician a high degree of portability, permitting utilization among multiple clinic sites.
Article
The effect of infrared low-intensity laser irradiation on functional activity of blood polymorphonuclear leukocytes was studied in vitro. A dose-dependent priming of polymorphonuclear leukocytes induced by infrared low-intensity laser irradiation was demonstrated. Similar effects were also observed in the presence of the photosensitizer photosense.
Article
We evaluated the acute electrophysiologic effects of low-energy pulsed laser irradiation, measured by extracellular recording technique on compound action potential configuration and nerve excitability in the isolated frog sciatic nerve A pulsed gallium-arsenide (GaAs) laser (wavelength, 904 nm; pulse duration, 220 nanoseconds; peak power per pulse, 27 W; spot size, 0.28 cm(2); total applied energy density, 0.005-2.5 J/cm(2)) was used for the experiment. Sixty isolated nerves were divided into six groups (n = 10), each of which received a different repetition frequency. In each group, action potentials were recorded, before laser irradiation, which served as the control data. The extracellular action potentials were recorded for each combination of 1, 3, 5, 7, 10, 13, and 15 minutes of irradiation time and 4, 8, 16, 32, 64, 128 repetition frequency by using a BIOPAC MP 100 Acquisition System Version 3.5.7 (Santa Barbara USA). Action potential latency, duration of depolarization and repolarization, and the stimulating voltage were measured. Statistical evaluation was performed using linear correlation analysis by SPSS 9.05. Although there was no correlation between applied energy density and action potential latency, the duration of depolarization and repolarization phases (P > 0.05), there was a weak correlation between applied energy density and stimulating voltage. The study showed that low-energy GaAs irradiation at 42 different energy density between 0.005 and 2.5 J/cm(2) generates no effect on action potential configuration and nerve excitability.
Article
The aim of this study was to determine, by the use of regression analysis, the factors that are associated with the increased plantar pressure in the diabetic foot. In-shoe plantar pressure measurements using the Novel Pedar were carried out on 50 subjects with diabetes. Variables measured were age, body weight, duration of diabetes, a number of selected structural radiographic angles, soft tissue thickness, plantarflexion, and dorsiflexion strength at the ankle and first metatarsophalangeal joint, Neuropathy Symptom Score, and the Michigan Neuropathy Disability Score. Stepwise regression modelling indicates that 28% of the variability in hallux peak pressure could be explained by the first metatarsophalangeal joint range of motion and the Michigan Neuropathy Disability Score (P=.0004). The Michigan Neuropathy Disability Score explained 17% of the peak pressure under the first metatarsal head (P=.002). None of the measured variables could explain any of the variation in peak pressure plantar to the lateral forefoot. Thirty-two percent (32%) of the variability in peak pressure under the heel was explained by the Michigan Neuropathy Disability Score and age (P<.0001). Very little of the variation in the pressure time integrals could be explained by the measured variables except for 10.3% of the variation in the pressure time integral for the heel being explained by body weight. This study has shown that neuropathy-related variables play an important role in the plantar pressure under the diabetic foot. The range of motion of the first metatarsophalangeal joint is also important in determining pressures under the hallux.
Article
Low-intensity laser irradiation has been shown to induce wound healing in conditions of reduced microcirculation, which is in part explained by systemic effects. We therefore investigated such a potential systemic effect of low-intensity laser irradiation on skin blood circulation in patients with diabetic microangiopathy. Patients with diabetic microangiopathy were randomized to receive either a single helium-neon (HeNe, 632.8 nm) low-intensity laser irradiation with a dose of 30 J/cm(2) or a sham irradiation over the forefoot region in a double-blind, placebo-controlled clinical study. Skin blood circulation by means of temperature recordings over forefoot regions was detected by infrared thermography. Following a single transcutaneous low-intensity laser irradiation, a rise in skin temperature in both feet of the subjects in the laser group was noted, whereas in both feet of the subjects in the placebo group a drop in skin temperature occurred. The baseline-adjusted skin temperature 15 min after the end of the irradiation was significantly higher in the laser-treated forefeet compared to the placebo-"treated" forefeet (p < 0.0001); the baseline-adjusted difference in the temperature was 1.94 +/- 0.35 degrees C. Simultaneously, the baseline-adjusted skin temperature was significantly higher in the laser-untreated forefeet compared to the placebo-"untreated" forefeet (P < 0.0001); the baseline-adjusted difference was 1.70 +/- 0.33 degrees C. Our data show a significant increase in skin circulation due to athermic laser irradiation in patients with diabetic microangiopathy and point to the possibility of inducing systemic effects.
Article
Painful diabetic neuropathy is a common and particularly unpleasant long-term complication of diabetes that affects a significant minority of patients with distal polyneuropathy. After exclusion of other causes of neuropathic pain, attention should be focused on achieving optimal and stable glycaemic control avoiding flux of blood glucose levels, which have been shown to aggravate pain. Most patients will require pain control therapy and whilst the tricyclic drugs remain a first-line approach, their use is often hampered by predictable but troublesome side effects. Gabapentin, the only agent specifically licensed for the treatment of neuropathic pain in the United Kingdom, is useful in diabetic neuropathy and is generally better tolerated than the tricyclics. Additionally, other pharmacological and non-pharmacological pain management approaches may be useful. Patient education has a significant role to play in the avoidance of late neurological complications.
Article
Diabetic sensorimotor polyneuropathy (DSP) remains the most common microvascular complication of both type I and type 2 diabetes, and poses a unique set of management challenges in the prevention of foot complications. Although different quantitative tests are available, the preliminary diagnosis of DSP can be reliably made using simple and rapid screening tests in the family physician's office or in the diabetes clinic. The Semmes-Weinstein 10-g monofilament examination is a popular, simple clinical modality for the prediction of early DSP, foot ulceration, and amputation, and, in turn, a predictor of mortality in patients with diabetes. The management of DSP is centered on optimal glycemic control, diligent foot care, and pain control as a means of preventing the progression of DSP and reducing the morbidity associated with foot complications.
Article
Both blood vessels and nerves are vital channels to and from tissues. Recent genetic insights show that they have much more in common than was originally anticipated. They use similar signals and principles to differentiate, grow and navigate towards their targets. Moreover, the vascular and nervous systems cross-talk and, when dysregulated, this contributes to medically important diseases. The realization that both systems use common genetic pathways should not only form links between vascular biology and neuroscience, but also promises to accelerate the discovery of new mechanistic insights and therapeutic opportunities.
Article
Diabetic peripheral neuropathy (DPN) has been thought to be progressive and irreversible. Recently, symptomatic reversal of DPN was reported after treatments with a near-infrared medical device, the Anodyne Therapy System (ATS). However, the study was not controlled nor was the investigator blinded. We initiated this study to determine whether treatments with the ATS would decrease pain and/or improve sensation diminished due to DPN under a sham-controlled, double-blind protocol. Tests involved the use of the 5.07 and 6.65 Semmes Weinstein monofilament (SWM) and a modified Michigan Neuropathy Screening Instrument (MNSI). Twenty-seven patients, nine of whom were insensitive to the 6.65 SWM and 18 who were sensitive to this filament but insensitive to the 5.07 SWM, were studied. Each lower extremity was treated for 2 weeks with sham or active ATS, and then both received active treatments for an additional 2 weeks. The group of 18 patients who could sense the 6.65 SWM but were insensitive to the 5.07 SWM at baseline obtained a significant decrease in the number of sites insensate after both 6 and 12 active treatments (P < 0.02 and 0.001). Sham treatments did not improve sensitivity to the SWM, but subsequent active treatments did (P < 0.002). The MNSI measures of neuropathic symptoms decreased significantly (from 4.7 to 3.1; P < 0.001). Pain reported on the 10-point visual analog scale decreased progressively from 4.2 at entry to 3.2 after 6 treatments and to 2.3 after 12 treatments (both P < 0.03). At entry, 90% of subjects reported substantial balance impairment; after treatment, this decreased to 17%. However, among the group of nine patients with greater sensory impairment measured by insensitivity to the 6.65 SWM at baseline, improvements in sensation, neuropathic symptoms, and pain reduction were not significant. ATS treatments improve sensation in the feet of subjects with DPN, improve balance, and reduce pain.
Measuring agreement in method comparison studies
  • Jm Bland
  • Dg Altman
Bland JM, Altman DG (1999) Measuring agreement in method comparison studies. Stat Methods Med Res 8: 135-160.
Comparative effects of wavelengths of low-power laser in regeneration of sciatic nerve in rats following crushing lesion
  • R I Barbosa
  • A M Marcolino
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  • C H Barbieri
Barbosa RI, Marcolino AM, de Jesus Guirro RR, Mazzer N, Barbieri CH, et al. (2010) Comparative effects of wavelengths of low-power laser in regeneration of sciatic nerve in rats following crushing lesion. Lasers Med Sci 25: 423-430.