Therapeutic Effects Of Electrical Stimulation Research Articles

Development of a Cell Culture Chamber for Investigating the Therapeutic Effects of Electrical Stimulation on Neural Growth.

Natural electric fields exist throughout the body during development and following injury, and, as such, EFs have the potential to be utilized to guide cell growth and regeneration. Electrical stimulation (ES) can also affect gene expression and other cellular behaviors, including cell migration and proliferation. To investigate the effects of electric fields on cells in vitro, a sterile chamber that delivers electrical stimuli is required. Here, we describe the construction of an ES chamber through the modification of an existing lid of a 6-well cell culture plate. Using human SH-SY5Y neuroblastoma cells, we tested the biocompatibility of materials, such as Araldite®, Tefgel™ and superglue, that were used to secure and maintain platinum electrodes to the cell culture plate lid, and we validated the electrical properties of the constructed ES chamber by calculating the comparable electrical conductivities of phosphate-buffered saline (PBS) and cell culture media from voltage and current measurements obtained from the ES chamber. Various electrical signals and durations of stimulation were tested on SH-SY5Y cells. Although none of the signals caused significant cell death, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that shorter stimulation times and lower currents minimized negative effects. This design can be easily replicated and can be used to further investigate the therapeutic effects of electrical stimulation on neural cells.

Discussion on the Therapeutic Effect of Electrical Stimulation Combined with Exercise Therapy for Postpartum Rectus Abdominis Separation

Discussion on the Therapeutic Effect of Electrical Stimulation Combined with Exercise Therapy for Postpartum Rectus Abdominis Separation

Lidocaine Nerve Block Diminishes the Effects of Therapeutic Electrical Stimulation to Enhance Nerve Regeneration in Rats.

Although electrical stimulation (ES) can improve nerve regeneration, the impact of nerve block, such as lidocaine (Lido), on the therapeutic benefits of ES remains unclear. We used a rat tibial nerve transection-and-repair model to explore how either preoperative (PreOp) or postoperative (PostOp) nerve block affects ES-related improvement in regeneration. Lewis rats were used in 1 of 2 studies. The first evaluated the effects of extraneural Lido on both healthy and injured nerves. In the second study, rats were randomized to 5 experimental groups: No ES (negative control), PreOp Lido, ES + PreOp Lido, PostOp + ES, and ES (positive control). All groups underwent tibial nerve transection and repair. In both studies, nerves were harvested for histological analysis of regeneration distal to the injury site. Application of extraneural Lido did not damage healthy or injured nerve based on qualitative histological observations. In the context of nerve transection and repair, the ES group exhibited improved axon regeneration at 21 days measured by the total number of myelinated fibers compared with No ES. Fiber density and percentage of neural tissue in the ES group were greater than those in both No ES and PreOp Lido + ES groups. ES + PostOp Lido was not different from No ES or ES group. Extraneural application of Lido did not damage nerves. Electrical stimulation augmented nerve regeneration, but Lido diminished the ES-related improvement in nerve regeneration. Clinical studies on the effects of ES to nerve regeneration may need to consider nerve block as a variable affecting ES outcome.

Two-photon calcium imaging of neuronal and astrocytic responses: the influence of electrical stimulus parameters and calcium signaling mechanisms

Objective. Electrical brain stimulation has been used to ameliorate symptoms associated with neurologic and psychiatric disorders. The astrocytic activation and its interaction with neurons may contribute to the therapeutic effects of electrical stimulation. However, how the astrocytic activity is affected by electrical stimulation and its calcium signaling mechanisms remain largely unknown. This study is to explore the influence of electrical stimulus parameters on cellular calcium responses and corresponding calcium signaling mechanisms, with a focus on the heretofore largely overlooked astrocytes. Approach. Using in vivo two-photon microscopy in mouse somatosensory cortex, the calcium activity in neurons and astrocytes were recorded. Main results. The cathodal stimulation evoked larger responses in both neurons and astrocytes than anodal stimulation. Both neuronal and astrocytic response profiles exhibited the unimodal frequency dependency, the astrocytes prefer higher frequency stimulation than neurons. Astrocytes need longer pulse width and higher current intensity than neurons to activate. Compared to neurons, the astrocytes were not capable of keeping sustained calcium elevation during prolonged electrical stimulation. The neuronal Ca2+ influx involves postsynaptic effects and direct depolarization. The Ca2+ surge of astrocytes has a neuronal origin, the noradrenergic and glutamatergic signaling act synergistically to induce astrocytic activity. Significance. The astrocytic activity can be regulated by manipulating stimulus parameters and its calcium activation should be fully considered when interpreting the mechanisms of action of electrical neuromodulation. This study brings considerable benefits in the application of electrical stimulation and provides useful insights into cortical signal transduction, which contributes to the understanding of mechanisms underlying the therapeutic efficacy of electrical stimulation for neurorehabilitation applications.

Monophasic Pulsed Current Stimulation of Duty Cycle 10% Promotes Differentiation of Human Dermal Fibroblasts into Myofibroblasts.

Many clinical trials have shown the therapeutic effects of electrical stimulation (ES) in various conditions. Our previous studies showed that ES (200 μA and 2 Hz) promotes migration and proliferation of human dermal fibroblasts (HDFs). However, the effective duty cycle and the effect of ES on myofibroblast differentiation are unclear. This study aimed to investigate the relationship between duty cycle and myofibroblast differentiation. HDFs were subjected to ES (200 μA and 2 Hz) for 24 h with the duty cycle adapted at 0% (control), 10%, 50%, or 90%. α-smooth muscle actin (SMA) and transforming growth factor (TGF)-β1 mRNA and α-SMA protein expressions were assessed. Collagen gel contraction was observed for 48 h after ES initiation and the gel area was measured. Cell viability and pH of culture medium were analyzed for cytotoxicity of the ES. Cell viabilities were decreased in the 50% and the 90% groups but ES did not influence on pH of culture media. ES with a duty cycle of 10% significantly promoted the mRNA expression of α-SMA and TGF-β1. α-SMA protein expression in the 10% group was also significantly higher than that of the control group. Collagen gel subjected to ES with a duty cycle of 10% was contracted. Duty cycle can influence on myofibroblast differentiation and ES with a duty cycle 10% is the effective for wound healing.

Therapeutic Effect of Electrical Stimulation on Chronic Tinnitus: A Double Blind Randomized Controlled Trial

Chronic tinnitus is a disturbing condition that may affect different aspects of life. In this study, the therapeutic effect of electrical stimulation on chronic tinnitus was assessed. This was a clinical trial on 49 patients with persistent tinnitus for more than 6 months without a proper response to routine treatments. They were randomly allocated into two groups: the case group was treated with electrical stimulation for 6 sessions over 6 consecutive days, and the control group received a placebo. Before the intervention, one week and three months after the treatment sessions, patients were evaluated by comprehensive audiological assessments and hearing tests. The mean age of the participants was 40.37±9.32 and 41.35±9.24 in treatment and placebo groups, respectively. Tinnitus intensity was significantly decreased in the case group one week and three months after the treatment (P<0.05). Tinnitus handicap inventory score significantly decreased in the treatment group one week and three months after the treatment (P<0.05). There was no significant difference in tinnitus intensity after treatment, considering gender, age, tinnitus duration, and tinnitus type. Electrical stimulation could significantly reduce the severity of the tinnitus regardless of age, gender, duration, and type of tinnitus. © 2020 Tehran University of Medical Sciences. All rights reserved. Acta Med Iran 2020;58(1):4-8.

Fascicle specific targeting for selective peripheral nerve stimulation

Objective. Electrical stimulation is a blunt tool for evoking neural activity. Neurons are naturally activated asynchronously and non-uniformly, whereas stimulation drives simultaneous activity within a population of cells. These differences in activation pattern can result in unintended side effects, including muddled sensory percepts and undesirable muscle contractions. These effects can be mitigated by the placement of electrodes in close approximation to nerve fibers and careful selection of the neural interface's location. This work describes the benefits of placing electrodes within specific fascicles of peripheral nerve to form selective neural interfaces for bidirectional neuroprosthetic devices. Approach. Chronic electrodes were targeted to individual fascicles of the ulnar and median nerves in the forearm of four human subjects. During the surgical implant procedure, fascicles were dissected from each nerve, and functional testing was used to identify the relative composition of sensory and motor fibers within each. FAST-LIFE arrays, composed of longitudinal intrafascicular arrays and fascicular cuff electrodes, were implanted in each fascicle. The location, quality, and stimulation parameters associated with sensations evoked by electrical stimulation on these electrodes were characterized throughout the 90–180 d implant period. Main results. FAST-LIFE arrays enable selective and chronic electrical stimulation of individual peripheral nerve fascicles. The quality of sensations evoked by stimulation in each fascicle is predictable and distinct; subjects reported tactile and cutaneous sensations during stimulation of sensory fascicles and deeper proprioceptive sensations during stimulation of motor fascicles. Stimulation thresholds and strength-duration time constants were typically higher within sensory fascicles. Significance. Highly selective, stable neural interfaces can be created by placing electrodes within and around single fascicles of peripheral nerves. This method enables targeting electrodes to nerve fibers that innervate a specific body region or have specific functions. Fascicle-specific interfacing techniques have broad potential to maximize the therapeutic effects of electrical stimulation in many neuromodulation applications. (Clinical Trial ID NCT02994160.)

Influence of electrostimulation on the structural and functional characteristics of the muscles of the front abdomen

The purpose of the work is to study the effect of different-frequency electrical stimulation of the muscles of the anterior abdominal wall after hernioplasty.Research methods. Studies were performed on 40 rats with a simulated experimental ventral hernia after plasty with a polypropylene mesh. After hernioplasty, 20 animals received a physiotherapy course using pulsed electric current using the Neuro-pulse stimulator with various frequency characteristics (10, 100, 1000 Hz). Electrical stimulation was performed daily for 2 min for 10 days. The stimulation courses were repeated three times with 20‑day breaks. The material for the morphological study was prepared by the conventional method after 70 days.Results. The established degree of destructive changes in the muscles of the anterior abdominal wall in the area of the ventral hernia is directly dependent on the ratio of muscle and connective tissue fibers. The use of electrostimulation therapy enhances the repair processes and significantly reduces the recovery time of the structural and functional properties of skeletal muscles after modelling a ventral hernia with subsequent plastic surgery with a polypropylene mesh. The greatest therapeutic effect of electrical stimulation is observed at an electric field frequency of 10 Hz, and structural characteristics indicate a greater severity of signs of increased resistance to fatigue with a lower degree of functional tension of muscle fibers.Conclusion. Morphological changes in the rectus abdominis muscle, which are observed after electrostimulation, form the structural basis of the functional rehabilitation of the muscles of the anterior abdominal wall in ventral hernias.

Establishment of a canine slow transit constipation model and evalution of defecation, gastrointestinal transit and pathological sections

Objective: To establish a canine model of slow transit constipation (STC), and to test the changes in defecation, gastrointestinal transit time and pathology sections. Methods: Baseline information was measured in 8 beagle dogs, and these dogs were randomly divided into the control group and the model group. The dogs in model group were given a diet of canned meat, as well as a combination of compound diphenoxylate and alosetron hydrochloride for 5 weeks. Dogs in control group were given normal diet with no special intervention. Stool frequency and consistency were observed and recorded daily, and the gastrointestinal transit time (GITT) were measured every week. All animals underwent the midline laparotomy and the colonic tissues were taken from the rectosigmoid colon, then investigated by light microscopy, electron microscopy, and immunohistochemistry to evaluate changes of protein gene product 9.5(PGP9.5), synaptophysin and c-kit between two groups. Results: 8 beagle dogs underwent all experiment items successfully.Both of the stool frequency and scores of stool consistency decreased in model group(F=6.568, P=0.043; F=25.954, P=0.002). GITT delayed in model group(F=42.573, P=0.001). After 5 weeks of intervention, in the model group, the myenteric neurons and interstitial cells of Cajal showed damage such as swelling of mitochondria under electron microscopy, and both of the PGP9.5 and synaptophysin integrated option density of rectosigmoid colon were decreased (t=3.471, P=0.013; t=2.506, P=0.046)under immunohistochemistry. The c-kit integrated option density showed no statistically significant differences between two groups(t=1.709, P=0.138). Conclusions: The canine model of STC which was consistent with clinical symptoms and pathological changes was successfully established, and it can be used to observe and evaluate the therapeutic effect of electrical stimulation, surgery and so on.

Therapeutic Effects of Electrical Stimulation: Interpretations and Predictions Based on the Visceral Theory of Sleep.

Therapeutic Effects of Electrical Stimulation: Interpretations and Predictions Based on the Visceral Theory of Sleep.

Measurement of Immediate Effect by Therapeutic Electrical Stimulation Using a New Desktop Rehabilitation Robot

Objective: More frequent use of robot technology in the field of rehabilitation is driving the need for smaller, less cumbersome devices. The objectives of the present study were to evaluate and compare quantitatively the upper limb function of chronic stroke patients before and after therapeutic electrical stimulation using a newly developed rehabilitation robot. Methods: Five stroke patients (3 men, 2 women; mean age: 66.4 ± 9.6 years; time since stroke: 36.0 ± 52.9 months) in the sub-acute and chronic phase of stroke-induced hemiplegia (induced by cerebral hemorrhage in four and by cerebral infarction in one; Brunnstrom stages III-V) participated in the study. None of them had any secondary motor neuron dysfunction or unstable disease control. Before and after 15 min of therapeutic electrical stimulation for repeated finger flexion and extension, participants performed reaching movements while moving the rehabilitation robot with their affected hand. Assessment parameters included Maximum swerve, Average speed, and smoothness of movements, as calculated by Jerk cost X (right-left direction) and Jerk cost Y (forward-backward direction). Results: All patients were able to use the rehabilitation robot to perform the reaching movements. Clear differences were observed before and after therapeutic electrical stimulation for Maximum swerve and Average speed in the X direction, and there was a tendency for Jerk cost X to differ before and after therapeutic electrical stimulation. In contrast, there were no significant differences in either Jerk cost Y or Average speed in the Y direction before and after the stimulation. Conclusion: The immediate effects of therapeutic electrical stimulation in chronic stroke patients can be quantified using our newly developed rehabilitation robot. Successful quantification of the effects of therapeutic electrical stimulation in stroke patients using smaller robotic systems could revolutionize the rehabilitation of these and other patients suffering from motor dysfunction or paralysis.

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

New methods for in vivo mapping of brain responses during deep brain stimulation (DBS) are indispensable to secure clinical applications. Assessment of current density distribution, induced by internally injected currents, may provide an alternative method for understanding the therapeutic effects of electrical stimulation. The current flow and pathway are affected by internal conductivity, and can be imaged using magnetic resonance-based conductivity imaging methods. Magnetic resonance electrical impedance tomography (MREIT) is an imaging method that can enable highly resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In the current study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The current density maps of three canine brains were calculated from the measured magnetic flux density data. The absolute current density values of brain tissues, including gray matter, white matter, and cerebrospinal fluid were compared to assess the active regions during DBS. The resulting current density in different tissue types may provide useful information about current pathways and volume activation for adjusting surgical planning and understanding the therapeutic effects of DBS.

Numerical simulation of electromagnetic field distribution induced in brain by electrical stimulation

Deep brain stimulation (DBS) is widely used for the treatment of various neurological diseases such as Parkinson's disease and tremors. Owing to the inherent limitations of the imaging modalities, physicians have a difficulty in the diagnosis of the exact response to the brain tissues during stimulation. Recent magnetic resonance (MR)-based electrical impedance tomography (MREIT) enables estimation of the current density distribution from the measured magnetic flux density data. Applying MREIT to DBS, one can predict the current pathway and electric field distribution which could be useful information for proving the therapeutic effects of electrical stimulation.

S5-3. New strategy of therapeutic electrical stimulation for functional recovery among patients with central nervous system lesions

Supraspinal modulation and phase-related sensory input play an important role for the functional recovery of locomotion among patients with central nervous system (CNS) lesions. Reciprocal inhibition (RI) modulates reciprocating lower extremity movements such as locomotion and pedaling. The effects of therapeutic electrical stimulation (TES) on reciprocal inhibition are limited. Pedaling is widely used for rehabilitation of locomotion because it induces similar muscle activity to that observed during locomotion. We, therefore, applied pedaling and TES simultaneously and examined the effects on RI in healthy persons. Pedaling + TES induced stronger after-effects on RI compared with either intervention alone. Furthermore, we combined anodal transcranial direct current stimulation (anodal tDCS) with patterned electrical stimulation (PES) on the peroneal nerve. We applied anodal tDCS + PES to patients with incomplete spinal cord injury. Combination of anodal tDCS with PES significantly modulated RI and improved ankle movements. Combination of TES with pedaling or anodal tDCS could be effective for the functional recovery of locomotion among patients with CNS lesions.

Suppression of epileptiform activity by a single short-duration electric field in rat hippocampus in vitro

The mechanisms behind the therapeutic effects of electrical stimulation of the brain in epilepsy and other disorders are poorly understood. Previous studies in vitro have shown that uniform electric fields can suppress epileptiform activity through a direct polarizing effect on neuronal membranes. Such an effect depends on continuous DC stimulation with unbalanced charge. Here we describe a suppressive effect of a brief (10 ms) DC field on stimulus-evoked epileptiform activity in rat hippocampal brain slices exposed to Cs(+) (3.5 mM). This effect was independent of field polarity, was uncorrelated to changes in synchronized population activity, and persisted during blockade of synaptic transmission with Cd(2+) (500 μM). Antagonists of A(1), P(2X), or P(2Y) receptors were without effect. The suppressive effect depended on the alignment of the external field with the somato-dendritic axis of CA1 pyramidal cells; however, temporal coincidence with the epileptiform activity was not essential, as suppression was detectable for up to 1 s after the field. Pyramidal cells, recorded during epileptiform activity, showed decreased discharge duration and truncation of depolarizing plateau potentials in response to field application. In the absence of hyperactivity, the applied field was followed by slow membrane potential changes, accompanied by decreased input resistance and attenuation of the depolarizing afterpotential following action potentials. These effects recovered over a 1-s period. The study suggests that a brief electric field induces a prolonged suppression of epileptiform activity, which can be related to changes in neuronal membrane properties, including attenuation of signals depending on the persisting Na(+) current.

Does electrical stimulation reduce spasticity after stroke? A randomized controlled study

Objective: To investigate the therapeutic effect of electrical stimulation on plantarflexor spasticity in stroke patients. Design: A randomized controlled clinical trial study. Setting: Rehabilitation clinic of Semnan University of Medical Sciences. Subjects: Forty stroke patients (aged from 42 to 65 years) with ankle plantarflexor spasticity. Intervention: Fifteen minutes of inhibitory Bobath techniques were applied to one experimental group and a combination of 9 minutes of electrical stimulation on the dorsiflexor muscles and inhibitory Bobath techniques was applied to another group for 20 sessions daily. Main measures: Passive ankle joint dorsiflexion range of motion, dorsiflexion strength test, plantarflexor muscle tone by Modified Ashworth Scale and soleus muscle H-reflex. Results: The mean change of passive ankle joint dorsiflexion in the combination therapy group was 11.4 (SD 4.79) degrees versus 6.1 (SD 3.09) degrees, which was significantly higher (P = 0.001). The mean change of plantarflexor muscle tonicity measured by the Modified Ashworth Scale in the combination therapy group was -1.6 (SD 0.5) versus -1.1 (SD 0.31) in the Bobath group (P = 0.001). Dorsiflexor muscle strength was also increased significantly (P = 0.04) in the combination therapy group (0.7 ± 0.37) compared with the Bobath group (0.4 ± 0.23). However, no significant change in the amplitude of H-reflex was found between combination therapy (-0.41 ± 0.29) and Bobath (-0.3 ± 0.28) groups. Conclusion: Therapy combining Bobath inhibitory technique and electrical stimulation may help to reduce spasticity effectively in stroke patients.

Therapeutic effects of electrical stimulation on manual function of children with cerebral palsy: Evaluation of two cases

Purpose. To investigate changes in hand function associated with electrical stimulation for children with hemiplegic cerebral palsy.Method. An ABCA single-subject design, replicated in two children, was used in this study. Each baseline (phase A) lasted 4 weeks. Intervention consisted of electrical stimulation of wrist extensors (phase B) and of wrist extensors and flexors (phase C) for 15 minutes three times a week. Intervention phases also lasted 4 weeks. Active wrist extension range of movement and three timed manual tasks were tested two times a week every week. Data analysis included the Celeration Line and Two Standard Deviation Band methods in addition to visual analysis.Results. Significant performance gains were observed for both children, especially in phase C, when both extensors and flexors were stimulated. After intervention withdrawal, significant performance decreases were observed on most analysed variables.Conclusions. The observed performance changes seem to be associated with the presence of intervention and suggest that electrical stimulation can be a useful adjunct to improve hand function of children with cerebral palsy.

Influence of Physical Therapy on Body Movement ―Effects of Therapeutic Electrical Stimulation and Its Clinical Problem―

Influence of Physical Therapy on Body Movement ―Effects of Therapeutic Electrical Stimulation and Its Clinical Problem―

Therapeutic electrical stimulation to improve motor control and functional abilities of the upper extremity after stroke: a systematic review.

Therapeutic electrical stimulation (TES) is a therapeutic strategy aimed at improving impairments of the upper extremity in stroke. Assessment of the available evidence on the effect of TES of the affected upper extremity in improving motor control and functional abilities after stroke. A systematic literature search was performed to identify randomized controlled trials (RCTs) that have studied the effect of TES on motor control and functional abilities. The methodological quality of the studies was assessed systematically by two raters. The reported outcomes were examined to evaluate the effect of TES and to identify a possible relationship with patient characteristics, method of stimulation and methodological quality. When possible, effect sizes were calculated (Hedges' g). Six RCTs were included. The methodological scores ranged from 7 to 16 (maximum 19). All studies assessed the effect on motor control, and four reported a positive effect. Effect sizes calculated in three studies ranged from 0.55 to 1.46. Only two studies assessed the effect on functional ability, one reported a positive effect. Subgroup analyses in two studies suggest a better response to stimulation in less severely affected patients. Apart from this, no relationship between effect and patient characteristics, method of stimulation or methodological quality could be detected. The present review suggests a positive effect of electrical stimulation on motor control. No conclusions can be drawn with regard to the effect on functional abilities.

Therapeutic electrical stimulation in cerebral palsy: a randomized, controlled, crossover trial

The aim of this study was to evaluate the effect of therapeutic electrical stimulation (TES) applied to antagonists of spastic leg muscles on gross motor function in children with spastic diplegic cerebral palsy. Twelve children between 5 and 12 years of age completed a 24‐month crossover study in which six were randomly assigned to receive TES for the first 12 months and the remaining six for the last 12 months. Physiotherapy and a home training program were not altered. All were evaluated blindly in terms of tests of motor function and video recordings at the start and at 12 and 24 months. At the end of the study parents/carers gave a subjective assessment of the effect of TES. No significant effect of TES on motor or ambulatory function was found on the blinded evaluation, but parents of 11 of the 12 children stated that TES had a significant effect. We conclude that it is unlikely that TES has a significant effect on motor and ambulatory function in spastic diplegia.