Effects Of Magnetic Stimulation Research Articles

Therapeutic effects of acrobatic exercise and magnetic field exposure on functional recovery after spinal cord injury in mice

The effects of acrobatic exercise and magnetic stimulation (MS) in mice applied either separately or in combination while on recovery after spinal cord injury have been investigated. This progress has been compared in six groups of animals. The first two groups consisted of non-injured and injured animals, respectively, which were not exposed to any treatment. The third group included injured animals that participated in an acrobatic exercise and were exposed to MS applied at the frequency of 1 Hz. The animals in the fourth group were exposed to the MS (1 Hz) only, without performing any acrobatic exercises. While the mice in the fifth group participated in the acrobatic exercise and were exposed to MS at 15 Hz, the animals in group six received an acrobatic exercise without exposure to MS. The effects of the treatment were evaluated with the Basso Mouse Scale, the Horizontal Ladder Scale, and the Abnormal Posture Scale. While all groups showed improvement at the end of the study period, the animals that received exercise combined with 1 Hz MS demonstrated the best functional improvement. The animals exposed to the MS applied at a frequency of 15 Hz combined with acrobatic exercise, and those animals that were engaged in exercise and were not exposed to the MS, performed the worst. The area of the spared white matter at the lesion center correlated well with functional recovery and was greatest in the animals that received MS (1 Hz) combined with exercise.

A meta-analysis on transcranial magnetic stimulation for Parkinson's disease

Objective To systematically review findings on the effectiveness and safety of transcranial magnetic stimulation (TMS) for treating Parkinson's disease. Methods Foreign and Chinese databases were searched to find relevant trials. The searches were supplemented by searching the reference lists of the published trials. The studies were separated into two groups: those applying TMS at frequencies higher than 1 Hz, and those at 1 Hz or lower. Meta-analysis was performed with the aid of RevMan 5.0 software. Results Both low-frequency and highfrequency TMS can significantly reduce total scores on the Unified Parkinson's Disease Rating Scale (UPDRS) compared with sham stimulations. High-frequency TMS can significantly reduce UPDRS motor scores compared with sham stimulations. On the other hand, low-frequency TMS studies showed no significant overall improvement in motor scores, mental scores or in the activities of daily living (ADL) UPDRS scores. Low-frequency and high-frequency TMS studies also showed no significant overall improvement in Schwab and England ADL scores. Conclusions TMS therapy is safe and partially effective for treating Parkinson's disease. Key words: Transcranial magnetic stimulation; Parkinson's disease; Meta-analysis

Abstract A47: Possible effect of repetitive magnetic stimulation of the spinal cord on the limb angiogenesis in healthy rats and its clinical implication for the treatment of lymphedema

Abstract Objective: To investigate the effect of repetitive magnetic stimulation of the spinal cord on limb angiogenesis in healthy rats and explore its implication for the treatment of lymphedema. Methods: Twelve adult male Sprague-Dawley rats were divided into four groups as follows: sham repetitive magnetic stimulation (rMS) followed by tissue harvest 5 minutes later (group 1, n=2), 1 Hz rMS and tissue harvest 5 minutes later (group 2, n=3), 20Hz rMS and tissue harvest 5 minutes later (group 3, n=3), 20Hz rMS and tissue harvest 30 minutes later (group 4, n=4). Animals were treated with 20-minute rMS with 120% of the motor threshold on their left side of upper lumbar spinal cord. Expression of angiogenic factors, that is, Akt, phospho-Akt, endothelial nitric oxide synthase (eNOS), phospho-eNOS were measured by Western blot. Bilateral hindlimb muscles (quadriceps and gastrocnemius) were harvested. Results: Expression of eNOS in quadriceps muscle was markedly increased in group 3 and 4 (6.4 and 7.7-fold each compared with group 1, p=0.04). Also, expression of eNOS in gastrocnemius muscle was increased in group 2 and 3 than in group 1 (p=0.02). Expression of Akt in gastrocnemius muscle tends to increase in rMS- treated groups than in sham rMS group (p>0.05). Expression of phospho-Akt and phospho-eNOS were not comparable between four groups (p>0.05). Conclusion: Repetitive magnetic stimulation of the spinal cord may exert an angiogenic effect closely linked to lymphangiogenesis. It has clinical implication for the possible therapy of lymphedema caused by breast, cervical or endometrial cancer operation. Future studies with the specific lymphatic endothelial cell markers are required to confirm the effect of repetitive magnetic stimulation on lymphangiogenesis. Citation Information: Clin Cancer Res 2010;16(14 Suppl):A47.

Generalized framework for stimulus artifact removal

Stimulation is extensively used in neuroscience research in diverse fields ranging from cognitive to clinical. Studying the effect of electrical and magnetic stimulation on neuronal activity is complicated by large stimulation-derived artifacts on the recording electrodes, which mask the spiking activity. Multiple studies have suggested a variety of solutions for the removal of artifacts and were typically directed at specific stimulation setups. In this study we introduce a generalized framework for stimulus artifacts removal, the Stimulus Artifact Removal Graphical Environment (SARGE). The framework provides an encapsulated environment for a multi-stage removal process, starting from the stimulus pulse detection, through estimation of the artifacts and their removal, and finally to signal reconstruction and the assessment of removal quality. The framework provides the user with subjective graphical and objective quantitative tools for assessing the resulting signal, and the ability to adjust the process to optimize the results. This extendable publicly available framework supports different types of stimulation, stimulation patterns and shapes, and a variety of artifact estimation methods. We exemplify the removal of artifacts generated by electrical micro- and macro-stimulation and magnetic stimulation and different stimulation protocols. The use of different estimation methods, such as averaging and function fitting is demonstrated, and the differences between them are discussed. Finally, the quality of removal is assessed and validated using quantitative measures and combined experimental-simulation studies. The framework marks a shift from “algorithm” and “data” centric approach to a “workflow” centric approach, thus introducing an innovative concept to the artifact removal process.

The Effect of Repetitive Transcranial Magnetic Stimulation Combined with Upper Limb Exercise on the Motor Function of Hemiplegic Upper Limb

The Effect of Repetitive Transcranial Magnetic Stimulation Combined with Upper Limb Exercise on the Motor Function of Hemiplegic Upper Limb

Analysis for Magnetic Stimulation Effects on Acupoint

Magnetic stimulation has become a very topical research area in bioelectromagnetics studies. One of the major problems in understanding the observed changes in biological systems resulting from exposures to magnetic fields is the relationship of biological changes to physical processes. It is well known that acupuncture has many varied physiologic effects on the functional systems of human subjects. However, there are still many unknown questions or issues pertinent to acupuncture which are yet to be answered. The combination of acupuncture with magnetic stimulation is, for example, an important aspect worthy of thorough clinical studies. In this paper, the effects for magnetic stimulation on acupoints are discussed in three ways: physical analysis based on electromagnetism; medical treatment analysis based on Chinese medical theory of acupuncture; experimental observations on the electroencephalographic (EEG) waveforms as a result of magnetic stimulation on some acupoints of the human subjects participating in this study.

-경혈 및 트리거 포인트에서- 미약 자기장을 이용한 근피로 회복 평가

The aim of this study was developing the non-invasive focused magnetic stimulation system(NI_FMSS) that can stimulates acupoints which are small parts and knotted muscular tissues. To evaluate pain treatment effect of the NI_FMSS, we caused muscle fatigue to 25 subjects in biceps of the arm. Then, we stimulated acupoints(trigger points) HT2 using low frequency stimulator(10 subjects) and NI_FMSS(10 subjects). The other 5 subjects had not been stimulated. We analyzed muscle fatigue recovery with median frequency, RMS and median power in frequency domain for 5 days. We checked the magnetic stimulation effect on acupoint by evaluation of muscle fatigue recovery. Therefore, we identified that the NI_FMSS was more efficient system to relieve muscle pain than electric-stimulation system.

The effect of magnetic stimulation on astrocyte migration and its mechanism

Objective To investigate the effect of magnetic stimulation on astrocyte migration and its mech-anism. Methods Twenty-four adult, healthy Spragne-Dawley rats were injected with 0.5 μl of 1% ethidium bro-mide (EB) in the left side of the dorsal spinal cord funiculus at the T_(10-11) level to make a local spinal cord injury mod-el. They were then randomly divided into four groups and exposed to 30 pulses of magnetic stimulation at 1 Hz and the following intensities: O T (Group A);1.9x40% T (Group B); 1.9x80% T (Group C); 1.9x100% T (Group D). On the 14th day after stimulation, the rats were sacrificed and the expression of glial fibrillary acidic protein (GFAP), microtubule associated protein-2 (MAP-2) and extracellular signal-regulated kinase 1/2 (ERK 1/2) were detected, and the volume of holes in the injured area of the spinal cord was measured. Quantitative analysis of the GFAP, MAP-2 and ERK1/2 expression was performed using immunohistochemistry and an image anal-ysis system. Results The volume of holes in the injured area of the spinal cord decreased with increasing stimula tion intensity. In the reduced area of the holes, the expression of GFAP and ERK 1/2 could be seen, but not MAP-2. Significant differences were revealed in the expression of GFAP and ERK 1/2 among the four groups, but it was always significantly higher in the magnetic stimulation groups than in the controls. Conclusions After magnetic stimulation, astrocytes migrate into the injured spinal cord's holes. Astroeyte migration increases with increased mag-netic stimulation intensity, which may be associated with high expression of ERK 1/2. Key words: Magnetic stimulation; Astrocytes; Migration

The effects of repetitive peripheral magnetic stimulation on spasticity and motor function in patients with spastic hemiparesis as add-on in neuro-rehabilitation

Introduction: An innovative therapy option to reduce pathological muscle tone and to stimulate cortical reorganization after stroke is repetitive peripheral magnetic stimulation (rpMS), generating repetitive contraction-relaxation cycles and enhancing proprioceptive input from the affected extremity. Only a few recent studies (Struppler et al. 2001, 2003) investigated short-term effects in patients with spastic muscle tone and demonstrated a reduced spasticity and an enhanced motor performance.

Effects of low-field magnetic stimulation on brain glucose metabolism

Echo planar imaging (EPI), the gold standard technique for functional MRI (fMRI), is based on fast magnetic field gradient switching. These time-varying magnetic fields induce electric (E) fields in the brain that could influence neuronal activity; but this has not been tested. Here we assessed the effects of EPI on brain glucose metabolism (marker of brain function) using PET and 18F 2-fluoro-2-deoxy-D-glucose (18FDG). Fifteen healthy subjects were in a 4 T magnet during the 18FDG uptake period twice: with (ON) and without (OFF) EPI gradients pulses along the z-axis (Gz: 23 mT/m; 250 μs rise-time; 920 Hz). The E-field from these EPI pulses is non-homogeneous, increasing linearly from the gradient's isocenter (radial and z directions), which allowed us to assess the correlation between local strength of the E-field and the regional metabolic differences between ON and OFF sessions. Metabolic images were normalized to metabolic activity in the plane positioned at the gradient's isocenter where E=0 for both ON and OFF conditions. Statistical parametric analyses used to identify regions that differed between ON versus OFF (p<0.05, corrected) showed that the relative metabolism was lower in areas at the poles of the brain (inferior occipital and frontal and superior parietal cortices) for ON than for OFF, which was also documented with individual region of interest analysis. Moreover the magnitude of the metabolic decrements was significantly correlated with the estimated strength of E (r=0.68, p<0.0001); the stronger the E-field the larger the decreases. However, we did not detect differences between ON versus OFF conditions on mood ratings nor on absolute whole brain metabolism. This data provides preliminary evidence that EPI sequences may affect neuronal activity and merits further investigation.

Near-infrared spectroscopy in psychiatry

Objective: Near-infrared spectroscopy (NIRS) has been increasingly employed in psychiatry for functional neuroimaging studies of sleepiness, fatigue, personality, aging, brain activation time course, transcranial magnetic stimulation effects, and psychiatric disorders such as schizophrenia, mood disorders, panic disorder, and eating disorder, owing to its advantages over fMRI and PET such as complete noninvasiveness, small apparatus for measurements, and the natural setting for its examination.Methods: Characteristics of frontal lobe function were investigated using multichannel NIRS machines in schizophrenia, unipolar depression, and bipolar depression. Changes of oxygenated-hemoglobin concentration (oxy-Hb) were monitored every 0.1s during a verbal fluency task using a Hitachi ETG-100 and ETG-4000 system with the probes placed on the subjects' frontal and temporal regions.Results: Three psychiatric groups demonstrated different patterns of oxy-Hb changes from those in the control group. The schizophrenic group was characterized by a reduced oxy-Hb increase during the task period followed by an oxy-Hb re-increase during the post-task period, the unipolar depression group by a smaller oxy-Hb increase, and the bipolar depression group by a comparable but delayed oxy-Hb increase.Conclusion: The observed patterns of oxy-Hb changes suggest the characteristics of reactivity of frontal lobe function: inefficient, reduced, and preserved but delayed in schizophrenia, unipolar depression, and bipolar depression, respectively. NIRS can be employed as a clinical laboratory test for diagnosis and treatment of psychiatric disorders in the near future.

Commentary on Mishra et al. (2010): Transcranial magnetic stimulation effects on craving: impressive therapy or therapeutic impressions?

Commentary on Mishra et al. (2010): Transcranial magnetic stimulation effects on craving: impressive therapy or therapeutic impressions?

The effect of low frequency repetitive transcranial magnetic stimulation on Parkinson's plus syndrome

Objective To study the effects of repeated transcranial magnetic stimulation(rTMS)on Parkinson's plus syndrome(PPS).Methods Fifteen in-patients with PPS were studied between 2005 and 2008.The patients received 1 Hz rTMS at an intensity 30%over the threshold.The rTMS was applied on the hand representive area of the bilateral first motor cortex,50 stimulations on each side,5 arrays,for 5 min,once daily for 15 d.Hamilton's depression scale(HAMD),Hamilton's anxiety scale(HAMA),the unified Parkinson's disease rating scale(UPDRS,which can be subdivided into UPDRS Ⅰ,UPDRS Ⅱ and UPDRS Ⅲ),an activities of daily living scale(ADL),the mini-mental state examination(MMSE)and motor evoked potential(MEP)were assessed before and immediately after 15 d of rTMS treatment. Results Average HAMD,HAMA,UPDRS,UPDRS Ⅱ and UPDRS Ⅲ scores all decreased,and ADL scores increased significantly after treatment,while UPDRSⅠand MMSE scores were unchanged before and after treatment.No significant changes in resting motor threshold or central motor conduction time of the MEP were observed after rTMS treatment. Conclusion Clinical symptoms of PPS patients improved after rTMS treatment and side effects were few.Depression,anxiety,motor function and ability in the activities of daily living improved greatly.Repeated transcranial magnetic stimulation is a potential treatment for PPS patients.There may be no correlation between the effective mechanism of rTMS and cortex excitation. Key words: Repeated transcranial magnetic stimulation; Parkinson's plus syndrome; Therapeuticeffects; Motor evoked potential

Hemisphere Asymmetrical Transcranial Magnetic Stimulation Effect on Parietal Cortex, Detected with Near Infrared Spectroscopy; Facilitation of spatial working memory task relevant with visuospatial attention task

Hemisphere Asymmetrical Transcranial Magnetic Stimulation Effect on Parietal Cortex, Detected with Near Infrared Spectroscopy; Facilitation of spatial working memory task relevant with visuospatial attention task

Effects of low-frequency magnetic stimulation on proliferation and differentiation of human neural stem cells &lt;I&gt;in vitro&lt;/I&gt;

Effects of low-frequency magnetic stimulation on proliferation and differentiation of human neural stem cells &lt;I&gt;in vitro&lt;/I&gt;

Electrophysiological Analysis of Transmission Via Spinal Pathways After Vertebral Trauma

Complex electrophysiological examination of the state of spinal neuronal mechanisms was carried out in patients after complicated vertebral trauma (n = 52). Electromyographic responses of the muscles of the upper and lower limbs evoked by stimulation of the peripheral nerves, effects of magnetic stimulation (MS) of the brain cortex (transcranial MS, TMS) and spinal roots, and somatosensory evoked potentials (SSEPs) were recorded. Partial disorders of the motor functions of the lower limbs were observed in 21 patients. Subjects with complete absence of movements of the limbs demonstrated two variants of the patterns of electrophysiological phenomena. In 21 patients, evoked potentials were entirely absent, while reduced MS-evoked motor responses (MS MRs) and SSEPs could be observed in 10 subjects. The presence of these potentials was indicative of partial preservation of the cerebrospinal pathways after damage to the spinal cord. Thus, estimation of the results of complex electrophysiological examination allows one to objectively verify the state and dynamics of transmission via the spinal pathways, to make justified the tactics of treatment, and to estimate the efficacy of the measures directed toward recovery of the lost functions of spinal mechanisms.

S1240 Effect of Extracorporeal Magnetic Stimulation of Sacral Nerve On Anorectal Function in Patients with Fecal Incontinence

G A A b st ra ct s loss of stool” as their sole reason, contradicting their answer on the e-PAQ -PF. The most frequently cited reasons for not discussing FI were “other health problems more important to discuss”(n=9), “able to manage symptoms on my own”(n=7), and “thought leakage was a normal part of aging”(n=4). 17 women indicated a most important reason; “other health problems more important”(n=4) and “normal part of aging”(n=3) were the most frequently chosen. No one chose embarrassment as the most important reason. Conclusion: Consistent with other reports, participants who had discussed FI in the past had more severe FI than those who had not. Some women who indicated FI in the past 4 weeks, did not consider themselves to have the problem for unclear reasons. Higher prioritization of other health problems, perception that they are able to manage FI on their own, and belief that FI is a normal part of aging were the most common reasons for not discussing FI with clinicians.

Effects of Magnetic Stimulation on Oxidative Stress and Skeletal Muscle Regeneration Induced by Mepivacaine in Rat

We investigated the effect of magnetic field stimulation (MS) on oxidative damage and skeletal muscle injury prompted by mepivacaine injection in the anterior tibial muscle of Wistar rats. The effects of mepivacaine and MS on oxidative stress were evaluated by lipid peroxidation, GSH levels and catalase activity. Muscle regeneration was analyzed by haematoxylin-eosin stained, NADH-TR histochemical reaction, desmin immunostaining as well as by morphometric parameters such as fibers density and fiber area were evaluated. Our data revealed that mepivacaine induced oxidative stress, that MS prevents the harmful effects induced by mepivacaine and that it facilitates the regeneration process of skeletal muscle. In conclusion, the results show the ability of MS to modify skeletal muscle response to mepivacaine.

The Effect of Suprapubic Magnetic Stimulation in Patients with Neurogenic Detrusor Overactivity

Purpose: To evaluate the effect of suprapubic magnetic stimulation (SMS) with the use of an arm-type magnetic stimulator for the treatment of patients with neurogenic detrusor overactivity. Materials and Methods: Eleven patients with neurogenic detrusor overactivity were enrolled in this study. All patients underwent more than 16 SMS sessions, two times per week, with the use of an arm-type magnetic stimulator. Objective success was defined as a significant reduction (≥50%) in the total number of leakage episodes per 24 hours, whereas subjective success was defined as the request to continue treatment. Results: Five (71.4%) of 7 patients who had urinary incontinence before treatment reported objective success, and 3 patients showed no incontinence. A total of 6 (75.0%) of 8 patients showed increased average voiding volume. One patient showed an adverse effect of back pain after SMS and dropped out. Seven patients (70.0%) of 10 patients wanted to continue this treatment. They showed significant improvements in frequency/volume chart data, quality of life scores, and urodynamic data. Conclusions: SMS can be a safe, non-invasive and effective option for the treatment of neurogenic detrusor overactivity. (J Korean Continence Soc 2009;13:128-33)

Functional magnetic stimulation in constipation associated with Parkinson’s disease

The aims of this study were: (i) to investigate the effect of functional magnetic stimulation on total colonic transit time in patients with Parkinson's disease; (ii) to compare the changes in dynamic recto-anal behaviour during filling and defaecation in response to this regimen; and (iii) to study the carry-over effects with a 3-month follow-up. A longitudinal, prospective before-after trial. Sixteen patients with Parkinson's disease enrolled in this study. No subject withdrew from the study as a result of serious adverse events. A 3-week magnetic conditioning protocol, consisting of a 20-min stimulation session twice daily. Colonic transit time, Knowles-Eccersley-Scott Symptom Questionnaire and the dynamics of defecography were carried out before the intervention and on the final day of the protocol. There was a statistically significant reduction in colonic transit time and in the questionnaire score following the intervention. The difference in the anorectal angles between resting and evacuating process and the changes in pelvic floor descent all reached significance after the intervention. The therapeutic effects that achieved significance remained constant in the 3-month follow-up result. Functional magnetic stimulation may facilitate colonic motility in Parkinson's disease and straighten the anorectal angle, allowing smooth access of rectal contents to the anal canal.