Transcutaneous Electrical Nerve Stimulation Electrodes Research Articles

Enhancing the selective electrical activation of human vagal nerve fibers: a comparative computational modeling study with validation in a rat sciatic model

Objective. Vagus nerve stimulation (VNS) is an emerging treatment option for a myriad of medical disorders, where the method of delivering electrical pulses can vary depending on the clinical indication. In this study, we investigated the relative effectiveness of electrically activating the cervical vagus nerve among three different approaches: nerve cuff electrode stimulation (NCES), transcutaneous electrical nerve stimulation (TENS), and enhanced TENS (eTENS). The objectives were to characterize factors that influenced nerve activation and to compare the nerve recruitment properties as a function of nerve fiber diameter. Methods. The Finite Element Model, based on data from the Visible Human Project, was implemented in COMSOL. The three simulation types were compared under a range of vertical and horizontal displacements relative to the location of the vagus nerve. Monopolar anodic stimulation was examined, along with latency and activation of different fiber sizes. Nerve activation was determined via the activating function and McIntyre-Richardson-Grill models, and activation thresholds were validated in an in-vivo rodent model. Results. While NCES produced the lowest activation thresholds, eTENS generally performed superior to TENS under the range of conditions and fiber diameters, producing activation thresholds up to three times lower than TENS. eTENS also preserved its enhancement when surface electrodes were displaced away from the nerve. Anodic stimulation revealed an inhibitory region that removed eTENS benefits. eTENS also outperformed TENS by up to four times when targeting smaller diameter nerve fibers, scaling similar to a cuff electrode. In latency and activation of smaller diameter nerve fibers, eTENS results resembled those of NCES more than a TENS electrode. Activation threshold ratios were consistent in in-vivo validation. Significance. Our findings expand upon previously identified mechanisms for eTENS and further demonstrate how eTENS emulates a nerve cuff electrode to achieve lower activation thresholds. This work further characterizes considerations required for VNS under the three stimulation methods.

Transcutaneous electrical nerve stimulation with the injection of pethidine and promethazine in the labor pain reduction: A randomized controlled trial.

The use of transcutaneous electrical nerve stimulation (TENS) to relieve labor pain remains controversial and existing evidence is neither strong nor consistent. This research was designed to compare TENS' effectwith the injection of pethidine and promethazine in labor pain reduction. In this trial, for 45 pregnant women in the active phase of labor, TENS electrodes were placed (two on both arms, and two over the participants' low back) continuously for 120 minutes; and for another group 45 pregnant women, 100 milligrams of pethidine and 250 micrograms of promethazine were injected intramuscularly which could be repeated once at least one hour later. Labor pain and duration, need for labor induction/augmentation/other pain control methods/ instrumental delivery, delivery type, and maternal and newborn complications were measured in both groups. The baseline mean visual analog scale (VAS) score, in the TENS group was 8.51±0.62 and in the pethidine and promethazine groups was 8.37±0.61 (P=0.31). While in a 120min post-intervention, it was 6.29±1.50 and 5.73±1.46 in the TENS group and the pethidine and promethazine group, respectively with no statistically significant difference (P=0.07). The labor duration in the TENS group was 6.61±1.71 hours and in the pethidine and promethazine group was 6.17±2.07 hours, with no statistically significant difference (P=0.33). In addition, no complication was recorded neither in the mothers nor newborns. This study showed that applying TENS in the active labor phase can reduce at least two scores in patient labor pain with no significant complications.

To evaluate the efficiency of transcutaneous electrical nerve stimulation (TENS) on stimulated and unstimulated salivary flow rates in diabetic patients: An original research

Aims and objectives: The aim of the present study is to assess the effectiveness of TENS as a means of stimulating salivary function in type2 diabetes mellitus patients. Methods: A sample of 100 patients having diabetes mellitus were enrolled for the study after taking the informed consent. Unstimulated saliva was collected by low forced spitting method for 10 minutes in a graduated measuring jar. Stimulated saliva was collected after placing TENS electrodes over the cheek for 10 minutes in a graduated measuring jar. The values were analyzed and compared.Results: Our study sample included 100 diab etic patients, out of which 52 were males and 48 were females. The age of the patients ranged from 30 yrs to 78 yrs with a mean age of 48.8 yrs. The blood glucose level was found to be highest among males when compared to females. The improvement in salivary flow rates by using TENS was found to significant in different age groups. Conclusion: The study suggests that in patients with Diabetes, TENS was found to be helpful to improve the salivary flowrate. Female diabetic patients showed a statistically significant improvement in salivary flow rates after using TENS.

Development of wearable system for carpal tunnel syndrome

PurposeCarpal tunnel syndrome (CTS) is a hand disease caused by the pressing of the median nerve present in the palmar side of the wrist. It causes severe pain in the wrist, triggering disturbance during sleep. Different products like splints, braces and gloves are available in the market to alleviate this disease but there was still a need to improve the wearability, comfort and cost of the product. This study was about designing a comfortable and cost-effective wearable system for mild-to-moderate CTS. Transcutaneous electrical nerve stimulation (TENS) therapy has been used to reduce the pain in the wrist.Design/methodology/approachAfter simulation by using Proteus software (which allowed the researchers to draw and simulate electrical circuits using ISIS, ARES and PCB design tools virtually), the circuit with optimum frequency, i.e. 33 Hz was selected, and the circuit was developed on a printed circuit board (PCB). The developed circuit was integrated successfully into the half glove structure.FindingsThe developed product had good thermophysiological comfort and hand properties as compared to the commercially available product of the same kind. In vivo testing (It involves the testing with living subjects like animals, plants or human beings) was performed which resulted in 85% confirmed viability of the product against CTS. A glove with an integrated circuit was developed successfully to accommodate various sizes without any sex specifications in a cost-effective way to mitigate the issue of CTS.Research limitations/implicationsIndustrial workers, individuals frequently using their hands or those diagnosed with CTS may wish to use this product as therapy. The attention could not be paid to the aesthetic or visual appeal of the developed product.Originality/valueA very comfortable glove with integrated TENS electrodes was developed successfully to accommodate various sizes without any sex specifications in a cost-effective way to mitigate the issues of CTS.

Design of a TENS knee pad with integrated textile electrodes

Transcutaneous electrical nerve stimulation (TENS) is defined as the application of electrical current to the skin for paincontrol by the American Physical Therapy Association (APTA). The TENS treatment is extensively preferred since it issafe, not expensive and has no side effects when compared to drug therapy. TENS therapy is applied using clinical orportable type TENS devices and TENS electrodes. However, conventional electrodes are not hygienic because they arenot washable and their sticky structure makes patients uncomfortable. Furthermore, they are not suitable to beintegrated into a smart garment. In this study, a knee pad with integrated electrodes and textile transmission lines havebeen designed and developed to be used for TENS therapy. Electrical resistance values of textile electrodes andtransmission lines which are integrated into the knee pad were measured. The developed knee pad was connected toa commercially available TENS device and electrical current transmission on subjects was tested. Furthermore, washingtests were conducted on the knee pad.

Electrode Design for Electrotactile Feedback With Reduced Interference to Myoelectric Signal

As the electrical stimulation (ES) may coexist with myoelectric signal (EMG) collection in a bidirectional human-machine interface, the compatibility of these two channels must be ensured at first. From the perspective of optimization, it is feasible to reduce the ES-introduced interference in the EMG signal by refining the electrode design. In this paper, a mathematical model of the electric field about ES noise propagation was first established and then verified using finite element analysis (FEA). Based on the model, a novel concentric electrode configuration with optimized electrode size used for biphasic transcutaneous electrical nerve stimulation (TENS) was proposed. The design was finally verified on both non-woven electrode and flexible printed circuit (FPC)-substrate electrode for reducing the ES noise in the myoelectric signal. This study can be used to guide the design of various TENS electrodes, whether they are monomeric or arrayed electrodes, in a typical bidirectional human-machine interface for improving the afferent/efferent signal compatibility.

The efficacy of transcutaneous electrical nerve stimulation therapy in pain control after cesarean section delivery associated with uterine contractions and abdominal incision.

This study aims to investigate the effects of transcutaneous electrical nerve stimulation (TENS) therapy on the intensity of pain associated with uterine contractions and abdominal incision in patients undergoing cesarean section (C-section) delivery. This single-blind, prospective, randomized-controlled study included a total of 90 female patients (mean age 30.5 years; range, 25 to 36 years) who had a scheduled C-section delivery between November 2017 and April 2018. Forty-five postpartum patients were randomly assigned into the treatment group (Group 1) and TENS electrodes were placed below and above the abdominal incision. The control group (n=45) consisted of 45 patients who had a scheduled C-section (Group 2) (n=45) and received routine follow-up care. The Visual Numeric Scale (VNS) scores were obtained separately for abdominal, low back, and groin pain at baseline (within 1 h after C-section before the TENS replacement), at postpartum 2, 6, 24, and 48 h. In addition to instant scoring, the percentages of change in pain scores from baseline were also calculated for each time points. Data of a total of 87 patients were analyzed. No statistically significant difference was found in the baseline VNS scores measured in any body regions between the groups (p>0.05). However, there was a statistically significant difference in the instant VNS scores for abdominal pain at 2, 6, 24, and 48 h in favor of Group 1 (p<0.05). No significant differences were found in the instant VNS scores for low back and groin pain (p>0.05). The comparison of changes in pain scores from baseline (% change) over time between the groups revealed a statistically significant difference in favor of Group 1 in all VNS scores for abdominal, low back, and groin pain at 2, 6, 24, and 48 h (p<0.05). Our study results suggest that TENS is an effective and safe non-invasive, non-pharmacological treatment modality. It may be preferred as an alternative method in pain control in postpartum women after C-section delivery.

The Effects of Transcutaneous Electrical Nerve Stimulation on Post-Episiotomy Pain Severity in Primiparous Women: A Randomized, Controlled, Placebo Clinical Trial.

Background: Episiotomy or cutting the perineum is the most common operation in obstetrics. Perineal pain is the main complication of episiotomy that affects the quality of life and mental health of the mother. Reducing the pain and side effects of the chemical drugs prescribed for pain relief has attracted the attention of both physicians and scientists. This study was conducted to determine the effects of transcutaneous electrical nerve stimulation (TENS), as an alternative method, on post-episiotomy pain severity. Materials and Methods: This randomized clinical trial was performed on 120 primiparous women who had referred to Sanandaj Besat Hospital in 2018. The patients were divided randomly into three groups, including the intervention group (TENS-On), the placebo group (TENS-Off), and the control group. TENS electrodes were placed near the episiotomy site in genitofemoral and pudendal nerves. The pain was measured after episiotomy in lying, sitting, and activity positions. The pain severity was measured using a pain measurement instrument (numeral rating score) at four-time points, i.e., before the intervention as well as 30, 60, and 120 minutes after the TENS intervention. For data analysis, Pearson correlation, student’s t-test, Kruskal-Wallis test, ANOVA test, and Mann-Whitney U tests were used. Results: Intragroup evaluation results for placebo and control groups demonstrated no significant difference in the pain score (P>0.05). A significant difference was observed between the mean pain severity of the intervention group and that of the group with walking activities (P=0.04). In terms of the intergroup evaluation, there was a significant difference observed between the mean pain severity of the lying position and that of the control group (P=0.008). Regarding the sitting position, no significant difference was observed between its mean pain severity and that of the other two groups (P=0.04). Conclusion: TENS is an effective and safe method for post-episiotomy pain relief and a routine method used in the obstetrics and gynecology ward.

The Effects of Transcutaneous Electrical Nerve Stimulation on Post-Episiotomy Pain Severity in Primiparous Women: A Randomized, Controlled, Placebo Clinical Trial

Background: Episiotomy or cutting the perineum is the most common operation in obstetrics. Perineal pain is the main complication of episiotomy that affects the quality of life and mental health of the mother. Reducing the pain and side effects of the chemical drugs prescribed for pain relief has attracted the attention of both physicians and scientists. This study was conducted to determine the effects of transcutaneous electrical nerve stimulation (TENS), as an alternative method, on post-episiotomy pain severity. Materials and Methods: This randomized clinical trial was performed on 120 primiparous women who had referred to Sanandaj Besat Hospital in 2018. The patients were divided randomly into three groups, including the intervention group (TENS-On), the placebo group (TENS-Off), and the control group. TENS electrodes were placed near the episiotomy site in genitofemoral and pudendal nerves. The pain was measured after episiotomy in lying, sitting, and activity positions. The pain severity was measured using a pain measurement instrument (numeral rating score) at four-time points, i.e., before the intervention as well as 30, 60, and 120 minutes after the TENS intervention. For data analysis, Pearson correlation, student’s t-test, Kruskal-Wallis test, ANOVA test, and Mann-Whitney U tests were used. Results: Intragroup evaluation results for placebo and control groups demonstrated no significant difference in the pain score (P&gt;0.05). A significant difference was observed between the mean pain severity of the intervention group and that of the group with walking activities (P=0.04). In terms of the intergroup evaluation, there was a significant difference observed between the mean pain severity of the lying position and that of the control group (P=0.008). Regarding the sitting position, no significant difference was observed between its mean pain severity and that of the other two groups (P=0.04). Conclusion: TENS is an effective and safe method for post-episiotomy pain relief and a routine method used in the obstetrics and gynecology ward. [GMJ.2019;8:e1404]Â

Development of a method to maximize the transcutaneous electrical nerve stimulation intensity in women with fibromyalgia.

IntroductionTranscutaneous electrical nerve stimulation (TENS) is a non-pharmacological intervention clinically used for pain relief. The importance of utilizing the adequate stimulation intensity is well documented; however, clinical methods to achieve the highest possible intensity are not established.ObjectivesOur primary aim was to determine if exposure to the full range of clinical levels of stimulation, from sensory threshold to noxious, would result in higher final stimulation intensities. A secondary aim explored the association of pain, disease severity, and psychological variables with the ability to achieve higher final stimulation intensity.MethodsWomen with fibromyalgia (N=143) were recruited for a dual-site randomized controlled trial – Fibromyalgia Activity Study with TENS (FAST). TENS electrodes and stimulation were applied to the lumbar area, and intensity was increased to sensory threshold (ST), then to “strong but comfortable” (SC1), then to “noxious” (N). This was followed by a reduction to the final stimulation intensity of “strong but comfortable” (SC2). We called this the Setting of Intensity of TENS (SIT) test.ResultsThere was a significant increase from SC1 (37.5 mA IQR: 35.6–39.0) to SC2 (39.2 mA IQR: 37.1–45.3) (p<0.0001) with a mean increase of 1.7 mA (95% CI: 1.5, 2.2). Linear regression analysis showed that those with the largest increase between SC1 and N had the largest increase in SC2–SC1. Further, those with older age and higher anxiety were able to achieve greater increases in intensity (SC2–SC1) using the SIT test.ConclusionThe SC2–SC1 increase was significantly associated with age and anxiety, with greater mean increases associated with older age and higher anxiety. Thus, although all patients may benefit from this protocol, older women and women with elevated anxiety receive the greatest benefit.

Transcutaneous Electrical Nerve Stimulation at the Acupuncture Points to Relieve Pain of Patients Under Mechanical Ventilation: A Randomized Controlled Study

Background and objectiveElectrical stimulation and acupuncture points as nonpharmacological methods have been the focus of pain reduction in different patients. This study is aimed at determining the effects of transcutaneous electrical nerve stimulation (TENS) on the acupuncture points of pain in patients under mechanical ventilators. Materials and methodsThis randomized double-blind clinical trial study was conducted on 50 patients undergoing mechanical ventilation in intensive care units of Imam Reza hospital in Kermanshah, Iran, in 2017. The patients were randomly allocated into intervention and placebo groups. In the intervention group, TENS electrodes were placed on points Hegu and Zusanli. Pain severity was measured using the Care Pain Observation Tool scale, and the dosages of narcotics and sedation intake were recorded. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 19. ResultsThe level of pain in patients decreased in the intervention group in comparison with the sham group, and this decline was significant during certain hours (p < 0.05). The amount of analgesic and sedation drugs used was less significant in the intervention group than in the sham group (p = 0.01; p = 0.04). ConclusionThe results showed that the use of TENS on acupuncture points can decrease the level of pain and opioid consumption in intubated patients under a mechanical ventilator.

Comparison of Transcutaneous Electrical Nerve Stimulation and Lidocaine on Episiotomy Complication in Primiparous Women: A Randomized Clinical Trial.

Introduction:Transcutaneous electrical nerve stimulation (TENS) through the skin is a nonpharmacological method of pain relief. The present study aimed to compare TENS and lidocaine on episiotomy complication in primiparous women.Material and Methods:In a randomized, controlled clinical trial, 80 participants were included from March to July 2011 at the antenatal clinic and postdelivery ward in the Social Security Organization Hospital, Khorramabad, Lorestan, Iran. Data were collected using a demographic questionnaire, visual analog scale and redness, edema, ecchymosis, discharge, and approximation scales. The participants were randomized into two groups with equal number of participants. All participants received 5 cc of local infiltration of 1% lidocaine before episiotomy, and TENS electrodes were placed on He Gu and Shenmen points during the crowning of fetal head. The TENS group received TENS with 100; 250 μs, the output range of 15–20 mm amplifier from crowning of first stage of labor to the end of the episiotomy repairing. The lidocaine group received 10 cc of local infiltration of 1% lidocaine before episiotomy repair while did not receive TENS electrodes. The pain intensity during and after episiotomy repair was recorded.Results:TENS and lidocaine have similar effects on pain relief at the episiotomy cutting, the start of the episiotomy repair, and at end of the episiotomy repair; however, the pain relief of both the interventions was different during the episiotomy repair. The effect of TENS in reducing edema was statistically significant (P = 0.001).Conclusions:TENS and lidocaine are effective for the episiotomy complications during and after episiotomy repair.

Effect of transcutaneous electrical nerve stimulation through acupoints of Pucan (BL 61) and Shenmai (BL 62) on intraocular pressure in patients with glaucoma: a randomized controlled trial

ObjectiveTo investigate the effects of transcutaneous electrical nerve stimulation (TENS) through acupoints on the intraocular pressure (IOP) in patients with glaucoma. MethodsA single-blinded, randomized experimental design study was conducted. Patients from the North of Taipei Ophthalmology outpatient department diagnosed with intraocular hypertension were selected and were further enrolled if they met the research subject criteria. The patients who met all criteria, and who met no exclusion criteria became the participants. Participants were randomly assigned into the treated group, wherein the TENS electrodes (Qing Ming Medical Device Co., Ltd., New Taipei City, China) were applied with direct current (DC) on the acupoints Pucan (BL 61) and Shenmai (BL 62) for 20 min. The control group received no TENS electrode treatments. Measurements of IOP were taken four times using a pneumotonometer (Clinico Co., Ltd., New Taipei City, China), before, immediately after, 30 min after, and 60 min after TENS electrode treatments. ResultsEighty-two participants completed the experiment. IOP decreased more in the group treated with DC (P < 0.01) than in the control group. The lOPs were not affected by the age of the patients and their usage of medications. ConclusionTENS of acupoints of Pucan (BL 61) and Shenmai (BL 62) could significantly reduce the IOP in patients with glaucoma.

Effects of electrode size and spacing on sensory modalities in the phantom thumb perception area for the forearm amputees.

Tactile sensory feedback plays a key role in accomplishing the dexterous manipulation of prosthetic hands for the amputees, and the non-invasive transcutaneous electrical nerve stimulation (TENS) of the phantom finger perception (PFP) area would be an effective way to realize sensory feedback clinically. In order to realize the high-spatial-resolution tactile sensory feedback in the PFP region, we investigated the effects of electrode size and spacing on the tactile sensations for potentially optimizing the surface electrode array configuration. Six forearm-amputated subjects were recruited in the psychophysical studies. With the diameter of the circular electrode increasing from 3 mm to 12 mm, the threshold current intensity was enhanced correspondingly under different sensory modalities. The smaller electrode could potentially lead to high sensation spatial resolution. Whereas, the smaller the electrode, the less the number of sensory modalities. For an Φ-3 mm electrode, it is even hard for the subject to perceive any perception modalities under normal stimulating current. In addition, the two-electrode discrimination distance (TEDD) in the phantom thumb perception area decreased with electrode size decreasing in two directions of parallel or perpendicular to the forearm. No significant difference of TEDD existed along the two directions. Studies in this paper would guide the configuration optimization of the TENS electrode array for potential high spatial-resolution sensory feedback.

Prospective Phase II Study of the Efficacy of Transcutaneous Electrical Nerve Stimulation in Post-radiation Patients

AimsTo evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) delivered using an extra-oral device in patients with radiation-induced xerostomia. Materials and methodsThirty oral cavity and oropharyngeal cancer patients post-adjuvant (n = 26) or definitive radiotherapy (n = 4) were enrolled in this study. The TENS electrode pads were placed externally on the skin overlying the parotid glands. Unstimulated whole saliva was collected for 5 min into graduated tubes using the low forced spitting method. The TENS unit was then activated and stimulated saliva was collected for an additional 5 min. The difference between unstimulated and stimulated saliva output was measured using the paired t-test. Linear regression was used to determine factors significantly influencing the improvement in salivary output. ResultsTwenty-nine of 30 patients showed increased saliva flow during stimulation. A statistically significant improvement in saliva production (P < 0.05) during stimulation was noted. The mean unstimulated saliva flow was 0.056 ml/min and the mean stimulated saliva flow was 0.12 ml/min with a median increase of 0.06 ml/min. The interval to the application of TENS after radiotherapy significantly influenced the improvement in salivary flow. ConclusionExtra-oral application of TENS is effective in increasing the whole salivary flow in most of the post-radiated oral cavity/oropharyngeal cancer patients with xerostomia. TENS therapy may be useful as an effective supportive treatment modality in post-radiated oral cancer patients.

Effect of progressive muscular relaxation exercises versus transcutaneous electrical nerve stimulation on tension headache: A comparative study

Abstract Tension-type headache (TTH) is most frequent among all types of headaches. According to the International Headache Classification Subcommittee of the International Headache Society (2004), TTH occurs in 30–78% of the population. Progressive muscular relaxation exercises have been shown to reduce TTH, and home-based relaxation programmes can result in significant improvement in headaches. Transcutaneous electrical nerve stimulation (TENS) is a method of electrical stimulation that primarily aims to provide a degree of symptomatic pain relief by exciting sensory nerves and stimulating either the pain gate mechanisms or the opioid systems. The objective of this study was to compare between the effects of progressive muscular relaxation exercises and TENS on pain intensity and stress in people with TTH. Thirty patients with TTH were allocated to either Group A or Group B. Group A practised progressive muscular relaxation exercise, whereas Group B received TENS. In the latter group, TENS electrodes were placed bilaterally either on the head at the site of pain or on the occiput. The treatment was carried out for 15 minutes a day, for 7 days. Patients were assessed for pain intensity (Visual Analogue Scale) and level of stress (Lakaev Academic Stress Response Scale) before and after the intervention period. The results showed that progressive muscular relaxation exercises were effective in reducing pain as well as stress ( p p p = 0.233). Between-group analysis revealed that there was no statistically significant difference in reduction of pain between the two groups ( p = 0.595), but the amount of stress reduction in Group A ( p = 0.002) was significantly more than that in Group B. In conclusion, progressive muscular relaxation exercises were more effective in reducing stress level than TENS in patients with TTH. The effect on pain reduction was similar between the two treatment methods.

Transcutaneous electrical nerve stimulation for the relief of post-partum uterine contraction pain during breast-feeding: a randomized clinical trial.

To evaluate transcutaneous electrical nerve stimulation (TENS) used to relieve uterine contraction pain during breast-feeding in multiparous women. A controlled and randomized clinical trial was performed with 32 post-partum multiparous women who were breast-feeding. The participants were randomized into an experimental (EG, n = 16) and a control group (CG, n = 16). Pain was assessed using the Numerical Rating Scale and the descriptors of the Present Pain Intensity (PPI - McGill) during two sequential feeds. In the first assessment, the post-partum women in the EG and CG were monitored while breast-feeding and questioned regarding the degree of uterine contraction pain. In the second assessment, which was performed at the next feed, the EG used TENS while the CG was monitored, with pain being reassessed following. In the EG, the TENS electrodes were placed between T10-L1 and S2-S4, with a frequency of 100 Hz, a pulse duration of 75 μs and amplitude adjusted to produce a strong and tolerable sensation for 40 min. A descriptive analysis of the data and comparative intra- and intergroup analyses were performed by means of a non-parametrical test, with a significance level P ≤ 0.05. The level of basal pain was 5.56 in the EG and 5.50 in the CG. In the intragroup analysis, the EG (P < 0.0001) and CG (P = 0.04) presented significant pain reduction. In the intergroup analysis, the EG had significant pain reduction (P < 0.01) in comparison to the CG. In the PPI analysis, a non-significant decrease in pain intensity was observed in the EG. TENS was found to be effective in reducing post-partum uterine contraction pain during breast-feeding.

C2 Subcutaneous Stimulation for Failed Back Surgery Syndrome: A Case Report

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

P6 acupoint stimulation for prevention of postoperative nausea and vomiting in patients undergoing craniotomy: study protocol for a randomized controlled trial

BackgroundThe incidence of postoperative nausea and vomiting (PONV) is 50 to 79% after neurosurgery. Our study is designed to evaluate the efficacy of pericardium 6 (P6; also known as Neiguan) acupoint stimulation versus placebo, and versus routine antiemetic for the prevention of PONV after craniotomy, as well as to compare the efficacy of invasive acupuncture with non-invasive transcutaneous electrical nerve stimulation (TENS) on P6.Methods/designThis is a single-center, prospective, double-blind, five-arm, parallel-group, randomized controlled trial (RCT). All groups will be given routine intravenous ondansetron 8 mg administered before skin closure. Upon regaining consciousness from general anaesthesia, patients will receive one of five interventions: 1) P6 acupuncture bilaterally for 30 minutes, stimulated every 10 minutes to keep de qi sensation; 2) sham acupuncture bilaterally for 30 minutes with no stimulation; 3) P6 stimulation via active TENS electrodes bilaterally for 30 minutes, with stimulation frequency and intensity set to when de qi sensation is felt; 4) sham P6 stimulation via inactive TENS electrode bilaterally for 30 minutes; and 5) usual practice of pharmacological emesis prevention. The incidence of postoperative vomiting during the first 24 hours is the main outcome. Secondary outcomes include: complete response rate, severity of nausea, total rescue metoclopramide dose used and patient satisfaction with PONV management.DiscussionThe results from this study could potentially confirm that P6 acupoint stimulation is an effective adjunct to standard antiemetic drug therapy for the prevention of PONV in patients undergoing craniotomy. Our study may also confirm that conventional acupuncture is more effective than TENS.Trial registrationThis study is registered with the Chinese Clinical Trial Registry: ChiCTR-TRC-13003026.

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

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