[Impact of low level laser therapy on skin blood flow]. / Wplyw niskoenergetycznej laseroterapiina skorny przeplyw krwi.

UNLABELLED: The aim of this study was to objectively assess the impact of low level laser therapy on skin blood flow, in terms of two of its components - the flow and trophic and therapeutic effect. MATERIAL AND METHODS: Nineteen children aged 3-15 years have been included in the study (seven boys and twelve girls) with a diagnosis of meningomyelocele in the lumbosacral area. In nine of them (47.3%) bedsores were found in the area of paresis location. Studies of skin blood flow were performed using xenon 133 clearance in the Department of Nuclear Medicine of the Children's Memorial Health Institute. Xenon 133 radioisotope in saline with intrinsic activity 74 MBq in 1 ml was used as the marker. Laser application was performed immediately prior to the application of the marker with a tag shower 60 mW probe, emitting 680 nm red light with surface power density of 0.5 J/cm2. RESULTS: Within the tested children the laser application resulted in a significantly increased skin blood flow. Average results in tested group before LLLT are 7.47 ml/100 g/min, after LLLT 11.08 ml/100 g/min. CONCLUSIONS: 1. LLLT significantly increases the perfusion of the skin. 2. The effect of the increased perfusion as the result of laserotherapy in the most evident in children with skin trophic abnormalities. 3. Results confirmed by clinical observation indicate, that perfusion increase in relation to LLLT takes place with participation of trophic component of skin blood circulation.

Light therapy modulates serotonin levels and blood flow in women with headache. A preliminary study.

In this study, we looked at the possible effects of low-level laser therapy (LLLT) on blood flow velocity, and serotonin (5-HT) and cholinesterase levels in patients with chronic headache associated with temporomandibular disorders (TMD). LLLT has been clinically applied over the past years with positive results in analgesia and without the report of any side effects. The understanding of biological mechanisms of action may improve clinical results and facilitate its indication. Ten patients presenting headache associated with TMD completed the study. An 830-nm infrared diode laser with power of 100 mW, exposure time of 34 s, and energy of 3.4 J was applied on the tender points of masseter and temporal muscle. Blood flow velocity was determined via ultrasound Doppler velocimetry before and after laser irradiation. The whole blood 5-HT and cholinesterase levels were evaluated three days before, immediately, and three days after laser irradiation. Pain score after treatment decreased to a score of 5.8 corresponding to 64% of pain reduction (P < 0.05). LLLT promoted a decrease in the blood flow velocity (P < 0.05). In addition, the 5-HT levels were significantly increased three days after LLLT (P < 0.05). The cholinesterase levels remained unchanged at the analyzed time points (P > 0.05). Our findings indicated that LLLT regulates blood flow in the temporal artery after irradiation and might control 5-HT levels in patients suffering with tension-type headache associated to TMD contributing to pain relief.

Cerebral blood flow modulation by transcutaneous cranial electrical stimulation with Limoge's current.

OBJECTIVES: Transcutaneous cranial electrical stimulation (TCES) delivers a high-frequency (166 kHz) pulsed biphasic balanced current with a pulse repetition frequency of 100 Hz with 40% duty cycle through a negative electrode and two positive electrodes over the skull. TCES has a proven ability to potentiate anesthesia and analgesia, although the physiological mechanisms of this effect remain unclear. We hypothesized that the mechanism is a modulation of CBF in the central endogenous opioid system. This study aimed at determining the effects of TCES on CBF to elucidate its physiological mechanism. METHODS: Thirty-six healthy volunteers were randomly assigned to active or placebo TCES, and all assessments were double blind. TCES was performed using the Anesthelec™ device. In the stimulated group, an active cable was used, and in the control group (sham), the cable was inactive. CBF was measured by XeCT™ before and after two hours of TCES. RESULTS: Globally, CBF was unchanged by TCES. However, locally, TCES induced a significant CBF decrease in the brainstem and thalamus, which are structures involved in pain and anxiety (TCES and control CBF decrease were 18.5 and 11.9 mL/100g brain tissue/min, respectively). CONCLUSION: TCES can modulate local CBF but it has no effect on overall CBF. [Clinical Trials. gov number: NCT00273663].

Tumour perfusion assessment during regional hyperthermia treatment: comparison of temperature probe measurement with H(2)(15)O-PET perfusion.

PURPOSE: Hyperthermia treatment might increase tumour oxygenation and perfusion, as has been reported for experimental tumours. The present study was performed to investigate this hypothesis in patients undergoing regional hyperthermia treatment. METHODS: Thirteen patients with primary or recurrent pelvic tumours were included in this study. Prior to and up to one hour after regional hyperthermia, perfusion was quantitatively determined by H(2)(15)O-PET. The fused CT-PET images were used to extract tumour time-activity curves and to identify the catheter position. Perfusion was calculated from the total tumour time-activity curves and for the time-activity curves at the catheter site. Additionally, perfusion was calculated from the temperature-time curves measured using temperature probes. RESULTS: Perfusion values calculated using H(2)(15)O-PET and those deduced from temperature probe measurements are significantly correlated with a correlation coefficient, R = 0.21. The perfusion values deduced from the temperature measured in a body cavity do not provide information about average tumour perfusion. Perfusion values deduced from the temperature are overestimated for very poorly perfused tissues and underestimated for highly perfused tissues. CONCLUSIONS: Temperature measurement during hyperthermia may allow only determination of intermediate perfusion values.

[Comparative hemodynamic characteristics of patients with the organ of vision subjected to low-intensity laser radiation of the green and red wavelengths].

This comparative study was designed to evaluate effect of low-intensity speckle laser radiation in the green and red wavelengths on intraocular hemodynamics in 202 patients (202 eyes) with retinal vascular problems and without them. Irradiation was performed using "Izumrud" and "Rubin" adapters for an AMO-ATOS unit. Peak systolic velocity and peripheral resistance index in posterior short ciliary arteries and central retinal artery were measured. It was shown for the first time that green speckle laser radiation (wavelength 535 nm) has more pronounced (compared with the red light) effect on intraocular hemodynamics; thereby, it makes a greater contribution to the improvement of the visual function (e.g. in the case of glaucoma) and to the widening of the fields of vision.

Venous malformation of the eyelid treated with pulsed-dye-1064-nm neodymium yttrium aluminum garnet sequential laser: an effective and safe treatment.

Venous malformations of the skin and subcutaneous tissue are compressible, blue-purple tumors that are present at birth. According to the location and symptoms caused, venous malformations can be treated with surgery, sclerotherapy, or a combination of both. Laser therapy can also be used, especially when surgery is contraindicated. We report the case of a 24-year-old man who presented with a venous malformation on the upper and lower left eyelids, which provoked a mechanical ptosis. Treatment with sequential pulsed-dye neodymium yttrium aluminum garnet (PDL-Nd:YAG) laser was performed. After 2 treatments, a marked reduction of volume and blanching of the venous malformation was observed, with satisfactory cosmetic results. The sequential PDL-Nd:YAG laser seems to be an effective and safe therapy for the treatment of cutaneous venous malformations. It penetrates deeper than pulsed-dye laser alone, and because it allows the use of lower fluencies than Nd:YAG laser alone, it reduces the risk of adverse effects.

Spinal cord stimulation in the treatment of post-stroke patients: current state and future directions.

A decrease in cerebral blood flow (CBF) and brain metabolic activity are well-known complications of stroke. Spinal cord stimulation (SCS) is successfully being used for the treatment of several low-perfusion syndromes. The aim of this chapter is to describe the data that support the effect of SCS on CBF and the use of SCS in the treatment of stroke and cerebral low perfusion syndromes. In addition, we present our relevant studies. Since April 1995, we have assessed 49 non-stroke patients. The following parameters were measured pre- and post-stroke: (1) CBF in healthy contralateral tissue by single photon emission computed tomography (SPECT), (2) systolic and diastolic velocity in the middle cerebral artery (MCA) by transcranial Doppler, (3) blood flow quantification in the common carotid artery (CCA) by color Doppler, and (4) glucose metabolism in healthy contralateral tissue by positron emission tomography (PET). Our results showed that during cervical SCS there was a significant (p < 0.001) increase in systolic (> or =21%) and diastolic (>26%) velocity in the MCA, and CCA blood flow (> or =51%) as well as glucose metabolism (44%). We concluded that cervical SCS (cSCS) can modify CBF and brain metabolism. Its potential role in the management of stroke and low-perfusion syndromes is further investigated by experimental studies and reports describing clinical experience. Appropriate clinical trials are warranted.

Effects of pulsatile blood flow in large vessels on thermal dose distribution during thermal therapy.

The aim of this study is to evaluate the effect of pulsatile blood flow in thermally significant blood vessels on the thermal lesion region during thermal therapy of tumor. A sinusoidally pulsatile velocity profile for blood flow was employed to simulate the cyclic effect of the heart beat on the blood flow. The evolution of temperature field was governed by the energy transport equation for blood flow together with Pennes' bioheat equation for perfused tissue encircling the blood vessel. The governing equations were numerically solved by a novel multi-block Chebyshev pseudospectral method and the accumulated thermal dose in tissue was computed. Numerical results show that pulsatile velocity profile, with various combinations of pulsatile amplitude and frequency, has little difference in effect on the thermal lesion region of tissue compared with uniform or parabolic velocity profile. However, some minor differences on the thermal lesion region of blood vessel is observed for middle-sized blood vessel. This consequence suggests that, in this kind of problem, we may as well do the simulation simply by a steady uniform velocity profile for blood flow.

The influence of extremely low frequency magnetic fields on cytoprotection and repair.

Ischemia-reperfusion injuries, such as those suffered from various types of cardiovascular disease, are major causes of death and disability. For relatively short periods of ischemia, much of the damage is potentially reversible and in fact, does not occur until the influx of oxygen during the reperfusion stage. Because of this, there is a window of opportunity to protect the ischemic tissue. Here, we review several mechanisms of protection, such as heat shock proteins, opioids, collateral blood flow, and nitric oxide induction, and the evidence indicating that magnetic fields may be used as a means of providing protection via each of these mechanisms. While there are few studies demonstrating direct protection with magnetic field therapies, there are a number of published reports indicating that electromagnetic fields may be able to influence some of the biochemical systems with protective applications.

[Effect of magnet-laser therapy on the central nervous system functional state in patients with ischemic stroke].

Twenty three patients aged from 41 to 75, which have had ischemic stroke in the carotid basin (up to 2 years after an acute period of the stroke), have been examined. The course of magneto-laser therapy lasted 15 days. The author carried out neurological examinations, determined the state of psychoemotional activity, cerebral hemodynamics and frequency-amplitude indices of the brain to assess the mechanisms of MLT effect on the CNS functional state in patients being in a rehabilitative period after ischemic stroke. The course of MLT administration improves cerebral hemodynamics, increases the level of the bioelectrical activity of the brain. We can recommend based on obtained results MLT in the system of rehabilitation of patients which had had ischemic stroke.

Dynamic modeling of photothermal interactions for laser-induced interstitial thermotherapy: parameter sensitivity analysis.

A two-dimensional model was developed to model the effects of dynamic changes in the physical properties on tissue temperature and damage to simulate laser-induced interstitial thermotherapy (LITT) treatment procedures with temperature monitoring. A modified Monte Carlo method was used to simulate photon transport in the tissue in the non-uniform optical property field with the finite volume method used to solve the Pennes bioheat equation to calculate the temperature distribution and the Arrhenius equation used to predict the thermal damage extent. The laser light transport and the heat transfer as well as the damage accumulation were calculated iteratively at each time step. The influences of different laser sources, different applicator sizes, and different irradiation modes on the final damage volume were analyzed to optimize the LITT treatment. The numerical results showed that damage volume was the smallest for the 1,064-nm laser, with much larger, similar damage volumes for the 980- and 850-nm lasers at normal blood perfusion rates. The damage volume was the largest for the 1,064-nm laser with significantly smaller, similar damage volumes for the 980- and 850-nm lasers with temporally interrupted blood perfusion. The numerical results also showed that the variations in applicator sizes, laser powers, heating durations and temperature monitoring ranges significantly affected the shapes and sizes of the thermal damage zones. The shapes and sizes of the thermal damage zones can be optimized by selecting different applicator sizes, laser powers, heating duration times, temperature monitoring ranges, etc.

Objectivation of cerebral effects with a new continuous electrical auricular stimulation technique for pain management.

AIMS: The electrical point stimulation system (P-STIM) reflects a new, miniaturized system for pain therapy through ear acupuncture. For this reason, ultrathin needles were applied at the ear. The needles stimulate the acupuncture areas at the ear using electrical impulses, which come from a little generator applied behind the acupunctured ear. METHODS: This study describes continuous, non-invasive measurements of near infrared spectroscopy (NIRS) and multidirectional transcranial Doppler sonography in two healthy females (aged 23 and 27 years) during stimulation with P-STIM, for the first time. RESULTS: The results of the pilot measurements have shown that electrical point stimulation using the new electrical stimulation system on eye acupuncture points is able to modulate the mean blood flow velocity (vm) of the supratrochlear artery. These effects were present using a stimulation frequency of 100 Hz. A lower increase in vm was found in the middle cerebral artery. In addition, stimulus induced, quantifiable and reproducible alterations of the regional cerebral NIRS parameters were be detected. CONCLUSION: For the first time, P-Stim allows intermittent ear acupuncture stimulation for up to several days in combination with complete mobility for the patient.

Effects of successive repetitive transcranial magnetic stimulation on motor performances and brain perfusion in idiopathic Parkinson's disease.

We studied the effects of 0.2 Hz repetitive transcranial magnetic stimulation (rTMS) successively performed 6 times for 2 weeks in 12 patients with idiopathic Parkinson's disease (PD). Ten patients received rTMS to the bilateral frontal cortex (frontal rTMS) and six patients received rTMS to the bilateral occipital cortex (occipital rTMS). Before and after rTMS, we evaluated regional cerebral blood flow (rCBF) using 99m-Tc-ECD single photon emission computed tomography (SPECT) and clinical tests. In an analysis with statistic parametric mapping, both frontal and occipital rTMS reduced rCBF in the cortical areas around the stimulated site. The activities of daily living (ADL) and motor scores of Unified Parkinson's Disease Rating Scale (UPDRS), pronation-supination movements, and buttoning up significantly improved after frontal rTMS than before it, while occipital rTMS had no significant effects in clinical tests.The findings of the present study suggest that successive 0.2 Hz rTMS has outlasting inhibitory effects on neuronal activity around the stimulated cortical areas. Because there were no significant relations between improved clinical tests and reduced rCBF, we speculate that the indirect effects of 0.2 Hz rTMS on subcortical structures are related to improved parkinsonian symptoms. Further studies recruiting large numbers of subjects are required to confirm the efficacy of 0.2 Hz rTMS on PD.

Prostate perfusion in patients with locally advanced prostate carcinoma treated with different hyperthermia techniques.

PURPOSE: We determined prostate perfusion in 18 patients with locally advanced prostate carcinoma treated with a combination of external beam irradiation and regional (10) or interstitial (8) hyperthermia. MATERIALS AND METHODS: Perfusion values were calculated from temperature elevations due to constant applied power and from transient temperature measurements after a change in applied power. Student's t test was used for comparing perfusion values with time and in the 2 groups. RESULTS: At the start of regional hyperthermia treatment mean estimated perfusion plus or minus standard deviation was 10 +/- 8 ml./100 gm. per minute. At the end of treatment mean perfusion was increased to 14 +/- 2 ml./100 gm. per minute (p <0.01). Achieved thermal parameters were a mean temperature of at least 40.3C +/- 0.6C in 90% of the prostate, 40.9C +/- 0.6C in 50% and a mean maximum temperature of 41.6C +/- 0.6C. At the end of interstitial hyperthermia treatment estimated mean perfusion was 47 +/- 5 ml./100 gm. per minute, which was significantly different compared with the end of regional hyperthermia (p < 0(-7) ). Mean temperature was at least 39.4C +/- 0.9C in 90% of the prostate and 41.8C +/- 1.6C in 50%, while mean maximum temperature was 53.1C +/- 6.3C. Systemic temperature increased during regional hyperthermia up to 38.6C, whereas during interstitial hyperthermia body temperature was not elevated. CONCLUSIONS: During interstitial hyperthermia perfusion values are higher than during regional hyperthermia. Hyperthermia causes increased prostate perfusion.

Effects of diode laser therapy on blood flow in axial pattern flaps in the rat model.

Axial pattern skin flaps are a very important reparative tool for the plastic and reconstructive surgeon in the reconstruction of tissue defects. From whatever unfortunate reason, part or all of such flaps occasionally suffers from irreversible ischaemia with loss of the flap. Infrared diode laser therapy has been shown to improve local and systemic circulation. The present study was designed to assess the effect of an 830 nm diode laser (power density, 18.5 W/cm(2), energy density 185 J/cm(2)) on the blood flow of axial pattern flaps in the rat model and their survival, compared with unirradiated controls. The flaps were raised in all animals ( n=40), and blood flow assessed with laser speckle flowmetry (LSF). In the experimental groups (3 groups, n=10 per group), the flaps were irradiated either directly over the dominant feeder vessel (iliolumbar artery), at the proximal end or at the distal end of the flap itself and blood flow assessed during irradiation. Flowmetry was performed again in all animals at 5 and 10 min postirradiation, and the flaps sutured back in position. The unirradiated controls were handled in exactly the same way, but the laser was not activated. The survival rate of the flaps was assessed on the fifth postoperative day. LSF demonstrated significant increased blood flow in the flaps at 5 and 10 min postirradiation in all experimental groups compared with the control animals. At five days postirradiation, there was significantly better survival of the flaps in all the experimental groups compared with the controls ( p<0.01), but no significant difference was seen between any of the experimental groups. We conclude that laser therapy increases the blood flow and perfusion of transferred flaps, and that this has significant effects on the survival of the flaps. One possible mechanism of modulation of the autonomic nervous system is discussed.

The effect of evening primrose oil on the radiation response and blood flow of mouse normal and tumour tissue.

PURPOSE: To investigate the effect of the oral administration of evening primrose oil on the radiation response and the blood flow of normal tissue and a tumour in BALB/c mice. METHODS AND MATERIALS: Aliquots of evening primrose oil were fed to BALB/c mice daily and the radiation response of the skin was assessed by the determination of ED50 values for the incidence of moist desquamation, using probit analysis. Tumour radiosensitivity was investigated by determining the growth delay caused by irradiation of a transplantable rhabdomyosarcoma. The 86RbCl uptake technique was used to determine the blood flow in normal foot and tumour tissue. The fatty-acid content of red blood cells, plasma and tumour tissue was measured using gas chromatography. RESULTS: Daily evening primrose oil dietary supplementation reduced the sensitivity of skin to radiation-induced moist desquamation and prevented the radiation-associated increase in blood flow that was observed in this tissue. No modification of tumour blood flow or of tumour sensitivity to radiation resulted from evening primrose oil supplementation of mice. Evening primrose oil supplementation resulted in changes in plasma levels of linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA). These changes were contingent on whether the mice had been irradiated or not. In red blood cells evening primrose oil supplementation increased the GLA level of unirradiated mice and the LA level at 20 days after irradiation. There were no changes in tumour fatty-acid levels as a result of evening primrose oil treatment. CONCLUSIONS: Daily evening primrose oil supplementation reduced the sensitivity of skin to radiation-induced moist desquamation but did not alter tumour sensitivity to radiation.

Effects of PUVA and UVB treatments on restoration of epidermal barrier function and vascular response after suction blister injury in human skin in vivo.

PUVA and UVB phototherapies are used in the treatment of psoriasis and other inflammatory skin diseases. Ultraviolet radiation causes inflammation and modulates cell kinetics in the skin. PUVA also has an inhibitory effect on skin DNA synthesis. In this study, the effects of PUVA and UVB treatments on epidermal would healing were examined using the suction blister wound model. The healing of the wound was studied indirectly by measuring water evaporation and blood flow in the wound area. On the fourth day, water evaporation was more abundant in PUVA-treated patients (42 +/- 5 g/m2h) than in UVB treated (36 +/- 4 g/m2h) or control patients (27 +/- 3 g/m2h) (analysis of variance, the least significant difference test at a level of 0.05). The P value for the difference of means between the PUVA and control groups was 0.014. Blood flow was also more abundant during the fourth (PUVA 162 +/- 11 arbitrary units, UVB 122 +/- 10, controls 115 +/- 15) and sixth (PUVA 108 +/- 18, UVB 73 +/- 17, controls 57 +/- 13) day in PUVA treated patients (analysis of variance, the least significant difference test at a level of 0.05). The results suggest that PUVA treatment decreases the restoration of the epidermal barrier function. The PUVA-treated patients also showed a more intense and prolonged vascular response that may be due to PUVA-related inflammation.

Effects of microwave irradiation on blood flow in the dog hindlimb.

Physiotherapeutic doses of microwave irradiation to the hindlimb of the anaesthetized dog increased the temperature in the underlying skin and muscle by 5-6 degrees C and, after a latency of 2-8 min, heart rate, blood pressure and femoral conductance all increased. The conductance increase was predominantly in the paw. At this time plasma catecholamine levels were elevated above resting values. At the conclusion of irradiation, heart rate and blood pressure rapidly returned to basal levels, but there was a sustained increase in femoral conductance which was mainly in the leg. The results are discussed in terms of the likely mechanisms underlying the effects of microwave irradiation on limb blood flow and compared with those obtained with direct heating of arterial blood and limb tissue in the accompanying paper.