Sham Transcutaneous Electrical Nerve Stimulation Group Research Articles

Transcutaneous Electrical Nerve Stimulation (TENS) for the Treatment of Renal Colic in the ED: A Randomized, Double-Blind, Placebo-Controlled Trial

Study objective: To determine the analgesic efficacy of TENS treatment in patients with renal colic in the emergency department (ED). Methods: This double-blind, randomized controlled trial was conducted in a tertiary care ED. Patients with a definitive diagnosis of renal colic were assigned (1:1) as randomized to receive the real TENS with frequency 100 Hz, pulse width 200 microseconds, voltage 2 mA, or placebo with sham TENS. Pain intensity was measured using visual analog scales (VAS) at baseline, after 15 and 30th minutes. Results: A total of 100 patients were included in the final analysis: 50 patients treated with real TENS and 50 patients treated with sham TENS. VAS scores in both groups were similar at baseline. The mean reduction in VAS score at 15 min was 33.3 ± 17.6 (95% Confidence interval (CI): 28.3 to 38.3) for the real TENS group and 14.9 ± 11.6 (95% CI 11.6 to 18.2) for the sham TENS group (mean difference: 18.4 (95% CI: 12.5 to 24.4, P < 0.0001). The mean reduction in VAS score at 30 min was 63.7 ± 21.1 (95% CI: 57.7 to 69.7) for the real TENS group and 14.9 ± 16.2 (95% CI: 19.5 to 10.3) for the sham TENS group (mean difference: 48.8, 95% CI: 41.4 to 56.3, P < 0.0001). Four patients (8%) in the real TENS group and 24 patients (48%) in the sham TENS group required the rescue medication after 30th minutes. Conclusions: TENS is effective for acute pain treatment in renal colic patients in the ED. TENS therapy could be a treatment option for renal colic.

Transcutaneous electrical nerve stimulation for pain during propofol injection: a randomized clinical trial.

Propofol is a short-acting intravenous sedative widely used for procedural sedation and general anesthesia. However, pain during propofol injection is a distressing adverse effect. This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) could reduce pain during propofol injection compared to sham TENS. In a randomized controlled trial, 80 patients were allocated to two groups: the active TENS group received electrical stimulation via two electrodes on the venous cannulation site, whereas the sham TENS group received no stimulus. After 20 min following TENS, propofol 0.5 mg/kg pain was injected intravenously and pain was evaluated using a four-point score (0 = none, 1 = mild, 2 = moderate, 3 = severe). Adverse effects associated with TENS were also recorded. The overall incidence of pain during propofol injection was 47.5% in the TENS group and 87.5% in the sham group (P < 0.001). The incidence of moderate pain was significantly lower in the TENS group (7.5%) than in the sham TENS group (42.5%) (P < 0.001). There were no complications associated with TENS. Pre-treatment with TENS significantly reduced the incidence and intensity of pain during propofol injection.

Conservative Treatment Versus UltrasoundGuided Injection in the Management of Meralgia Paresthetica: A Randomized Controlled Trial

Background: Meralgia paresthetica (MP) is an entrapment mononeuropathy of the lateral femoral cutaneous nerve (LFCN), in which conservative treatment options are not always sufficient. Objectives: The aim of this study was to evaluate the efficacy of ultrasound (US)-guided LFCN injection in the management of MP by comparing with transcutaneous electrical nerve stimulation (TENS) therapy and sham TENS therapy. Study Design: A prospective, randomized, sham-controlled study. Setting: Health Sciences University Training and Research Hospital in Turkey. Methods: Patients diagnosed with LFCN compression with clinical and electrophysiological findings were included in this study. Patients were randomly assigned to 3 groups: (1) USguided injection group, (2) TENS group, and (3) sham TENS group. The blockage of the LFCN was performed for therapeutic MP management in group 1. Ten sessions of conventional TENS were administered to each patient 5 days per week for 2 weeks, for 20 minutes per daily session in group 2, and sham TENS was applied to group 3 with the same protocol. Visual Analog Scale (VAS), painDETECT questionnaire, Semmes-Weinstein monofilament test (SWMt), Pittsburgh Sleep Quality Index (PSQI), and health-related quality of life (36-Item Short Form Health Survey [SF36]) at onset (T1), 15 days after treatment (T2), and 1 month after treatment (T3) were used for evaluation. Patients and the investigator who evaluated the results were blinded to the treatment protocol during the study period. Results: A total of 54 of the 62 patients (group 1 n = 17, group 2 n = 16, group 3 n = 21) completed the study, 3 patients from group 1, 4 patients from group 2, and 1 patient from group 3 dropped out during the follow-up period. The mean changes in painDETECT and SWMt scores showed a statistically significant difference between groups in favor of group 1 at T2 and T3 compared with T1 (P &lt; 0.05). There was no statistically significant difference between groups in terms of VAS, SF-36, and PSQI scores (P &gt; 0.05). In-group analysis of VAS scores showed a statistically significant decrease in T2 and T3 compared with T1 in group 1 (P &lt; 0.05). In-group analysis of the VAS scores statistically significant decrease was shown in T2 compared with T1 in group 2 (P &lt; 0.05). In-group analysis of painDETECT scores statistically significant decrease was shown in T2 and T3 compared with T1 in all groups (P &lt; 0.05). In-group analysis of SWMt scores statistically significant decrease was shown in T2 and T3 compared with T1 in group 1 (P &lt; 0.05). In-group analysis of SF-36 and PSQI scores, there was no statistically significant decrease in all groups (P &gt; 0.05). Limitations: The limitation of the study was a short follow-up period. Conclusions: US-guided LFCN injection and TENS may be therapeutic options for MP treatment, however, for patients with neuropathic pain symptoms, US-guided LFCN injection may be a safe and alternative method to conservative treatment. Key words: Meralgia paresthetica, ultrasound-guided injection, transcutaneous electrical nerve stimulation

Transcutaneous electrical nerve stimulation (TENS) for pain management in sickle cell disease.

Sickle cell disease (SCD), one of the most common inherited disorders, is associated with vaso-occlusive pain episodes and haemolysis leading to recurrent morbidity, hospital admissions and work or school absenteeism. The crises are conventionally treated with opioids, non-opioids and other adjuvants with the risk of developing complications, addictions and drug-seeking behaviour. Different non-pharmacological treatments, such as transcutaneous electrical nerve stimulation (TENS) have been used for managing pain in other painful conditions. Hence, the efficacy of TENS for managing pain in SCD needs to be reviewed. To assess the benefits and harms of TENS for managing pain in people with SCD who experience pain crises or chronic pain (or both). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries and the reference lists of relevant articles and reviews. Date of the last search: 26 Febraury 2020. We included randomised controlled trials (RCTs) and quasi-RCTs, where TENS was evaluated for managing pain in people with SCD. Two review authors independently assessed the eligibility of the trials identified by the literature searches according to the inclusion criteria. Two review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using the GRADE guidelines. One double-blind cross-over RCT with 22 participants with SCD (aged 12 to 27 years) was eligible for inclusion. Following stratification into four pain crises severity grades, participants were then randomised to receive TENS or placebo (sham TENS). The trial was concluded after 60 treatment episodes (30 treatment episodes of each treatment group). There is a lack of clarity regarding the trial design and the analysis of the cross-over data. If a participant was allocated to TENS treatment for an episode of pain and subsequently returned with a further episode of a similar degree of pain, they would then receive the sham TENS treatment (cross-over design). For those experiencing a pain episode of a different severity, it is not clear whether they were re-randomised or given the alternate treatment. Reporting and analysis was based on the total number pain events and not on the number of participants. It is unclear how many participants were crossed over from the TENS group to the sham TENS group and vice versa. The trial had a high risk of bias regarding random sequence generation and allocation concealment; an unclear risk regarding the blinding of participants and personnel; and a low risk regarding the blinding of the outcome assessors and selective outcome reporting. The trial was small and of very low quality; furthermore, given the issue with trial design we were unable to quantitatively analyse the data. Therefore, we present only a narrative summary and caution is advised in interpreting the results. In relation to our pre-defined primary outcomes, the included trial did not report pain relief at two to four weeks post intervention. The trial authors reported that no difference was found in the changes in pain ratings (recorded at one hour and four hours post intervention) between the TENS and the placebo groups. In relation to our secondary outcomes, the analgesic usage during the trial also did not show any difference between groups. Given the quality of the evidence, we are uncertain whether TENS improves overall satisfaction as compared to sham TENS. The ability to cope with activities of daily living was not evaluated. Regarding adverse events, although one case of itching was reported in the TENS group, the site and nature of itching was not clearly stated; hence it cannot be clearly attributed to TENS. Also, two participants receiving 'sham' TENS reported a worsening of pain with the intervention. Since we have only included one small and very low-quality trial, with a high risk of bias across several domains, we are unable to conclude whether TENS is harmful or beneficial for managing pain in people with SCD. There is a need for a well-designed, adequately-powered, RCT to evaluate the role of TENS in managing pain in people with SCD.

Effect of preoperative transcutaneous electrical nerve stimulation on intraoperative anesthetic drug consumption and pain scores in patients undergoing lumbar discectomy under general anesthesia

Objective: Transcutaneous electrical nerve stimulation (TENS) is a common modality used to treat acute and chronic painful conditions. The aim of this study is to find out the effect of immediate preoperative TENS on intraoperative anesthetic drug consumption in patients undergoing lumbar discectomy under general anesthesia. Methods: Sixty patients undergoing lumbar discectomy were randomly divided into two study groups. In TENS group (Group T), TENS was applied for 1 h in the immediate preoperative period with 20 mA current, at 100 Hz frequency, in pulses of 250 μs on either side of the planned incision site. In Sham TENS group (Group S), TENS was applied for 1 h preoperatively to the patients, although with the current intensity set at “zero” mA. The pain intensity during rest as well as movement was recorded before and after TENS, by using the Visual Analog Scale (VAS) scores in both the groups. Intraoperatively, titrated doses of propofol were used to maintain a bispectral index value of 50 ± 5, and IV fentanyl was administered to maintain the heart rate and blood pressure within 20% of baseline values. Postoperatively, fentanyl 0.5 μg/kg IV was administered to achieve VAS of

Effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative pain intensity and mobility after hip fracture: A double-blinded, randomized trial.

BackgroundTranscutaneous electrical nerve stimulation (TENS) is a noninvasive modality which may be used to reduce acute postoperative pain. Intense perioperative pain within the first few days after hip fracture surgery is common and is related to negative consequences such as restricted and delayed ambulation.ObjectiveThe objective of the present study was to examine the effect of incorporating TENS treatment on pain intensity, and mobility, with standard rehabilitation care during the acute post-operative phase following Gamma-nail surgical fixation of extracapsular hip fractures.Materials and methodsForty-one patients were randomly assigned to a supplement of 30 mins of active TENS or sham TENS. The standard rehabilitation care included five daily 30 mins physical therapy treatments beginning 24 hrs after surgery. Outcome measures were: pain intensity at rest, at night and during ambulation (assessed with the Numeric Rating Scale; Functional Ambulation Classification instrument; time to complete five sit-to-stand tests; and two-minute walk test). Data were analyzed with Wilcoxon score rank tests. Significance was set at p≤0.05.ResultsSignificantly greater pain reduction during walking was noted in the active TENS group compared to sham TENS group (differences between the fifth and the second days: 2.55±1.37 vs 1.06± 1.11, respectively; p=0.0011). Additionally, advantage of active TENS was demonstrated in greater increase in walking distance on the fifth day and higher level of mobility compared to the sham TENS group. No additional effects of active TENS were noted on pain intensity at rest and at night and on five times sit-to-stand performance.ConclusionAddition of TENS to the standard care of elderly patients in the early days following Gamma nail surgical fixation of extracapsular hip fracture is recommended for pain management while walking and functional gait recovery. The effect of TENS on long-term functional outcomes should be explored in future studies.Trial registrationThe trial was registered at the ISRCTN registry: ID ISRCTN32476360.

Application of High-Frequency Transcutaneous Electrical Nerve Stimulation in Muscle Tension Dysphonia Patients With the Pain Complaint: The Immediate Effect

The aim of the present study was to investigate the immediate effect of the application of high-frequency Transcutaneous electrical nerve stimulation (TENS) in muscle tension dysphonia (MTD) patients with the pain complaint. Thirty patients with MTD, 10 men and 20 women with a mean age of 36.40 ± 5.76 years, participated in the study. The patients were randomized into two groups: (1) Treatment group (TENS) (10 women and 5 men) and (2) Sham TENS group (10 women and 5 men). The treatment group (TENS) received a unique 20-minute session of high-frequency TENS. The sham TENS group was treated in the same condition as the treatment group and received a unique 20-minute session of high-frequency TENS, but no stimulation was given. Auditory-perceptual assessments, acoustic voice analysis, vocal tract discomfort (VTD), and musculoskeletal pain were used to compare the patients pre- and post-treatment. There was a significant improvement in the asthenia parameter of auditory-perceptual assessment in the TENS group. This improvement in asthenia was significant when comparing the TENS group with the sham TENS group. These differences in the asthenia were not significant after using Holm-Bonferroni correction. A comparison of the VTD before and after the TENS application showed there was a significant reduction in the severity of the symptoms (burning, tight, dry, pain, tickling, sore, irritable, and lump in the throat). When comparing the TENS group with the sham TENS group, improvements in burn, tight, dry, pain, and irritable items of VTD were observed. However, after applying the Holm-Bonferroni correction, only reductions in dry and pain items remain significantly different between the groups. After the TENS application, the pain intensity was significantly reduced in the anterior and posterior neck, larynx, submandibular, masseter, temporal region, and upper back. After applying the Holm-Bonferroni correction, pain intensity reduction was significant in the anterior neck and larynx. When comparing the TENS group with the sham TENS group, pain intensity was reduced significantly in the larynx of the TENS group. This difference between the two groups was not significant after using Holm-Bonferroni correction. The pain and VTD assessments in the present study were performed using valid and reliable self-reported scales (NMSQ-E and VTD). High-frequency TENS can be used in the voice treatment program of patients with MTD. MTD patients with pain complaint reported that their vocal tract discomfort and pain were decreased following the high-frequency TENS. Notably, these positive effects were obtained after a single session of high-frequency TENS application.

A Pilot Randomized Controlled Trial of Transcutaneous Electrical Nerve Stimulation for Patients With Acute Tinnitus.

Background:This pilot study aimed to evaluate the feasibility effectiveness and safety of transcutaneous electrical nerve stimulation (TENS) for patients with acute tinnitus.Methods:A total of 46 eligible patients with acute tinnitus were entered and included in this randomized controlled trial. All the included patients were equally and randomly divided into a verum TENS group and a sham TENS group, each group 23 participants. All patients received parenteral intramuscular therapy of 1 ml Vitamin B12 weekly for a total of 4 weeks. In addition, they also underwent verum or sham TENS 30 min daily, 3 times weekly for 4 weeks. The primary efficacy endpoint was measured by the Tinnitus Severity Scale (TSS) and Tinnitus Questionnaire (TQ) sum score. The secondary efficacy endpoints were assessed by the Tinnitus Handicap Inventory (THI), 12-Item Short Form Health Survey (SF-12) questionnaire, and adverse events. All outcome efficacy endpoints were measured at baseline and after 4 weeks of treatment.Results:After 4-week treatment, the patients undergoing verum TENS showed statistically efficacy of symptoms relief, as measured by the scales of TSS (P < .01), TQ (P < .01), and THI (P < .01), and improvement of quality of life, as assessed by the SF-12 (P < .01), compared with patients receiving sham TENS. In addition, no adverse events related to the treatment were recorded in either group.Conclusions:The results of this study showed that verum TENS may benefit patients with acute tinnitus after 4 weeks of treatment.

Effectiveness of transcutaneous electrical nerve stimulation for the treatment of migraine: a meta-analysis of randomized controlled trials

BackgroundMigraine is now ranked as the second most disabling disorder worldwide reported by the Global Burden of Disease Study 2016. As a noninvasive neurostimulation technique, transcutaneous electrical nerve stimulation(TENS) has been applied as an abortive and prophylactic treatment for migraine recently. We conduct this meta-analysis to analyze the effectiveness and safety of TENS on migraineurs.MethodsWe searched Medline (via PubMed), Embase, the Cochrane Library and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials, which compared the effect of TENS with sham TENS on migraineurs. Data were extracted and methodological quality assessed independently by two reviewers. Change in the number of monthly headache days, responder rate, painkiller intake, adverse events and satisfaction were extracted as outcome.ResultsFour studies were included in the quantitative analysis with 161 migraine patients in real TENS group and 115 in sham TENS group. We found significant reduction of monthly headache days (SMD: -0.48; 95% CI: -0.73 to − 0.23; P < 0.001) and painkiller intake (SMD: -0.78; 95% CI: -1.14 to − 0.42; P < 0.001). Responder rate (RR: 4.05; 95% CI: 2.06 to 7.97; P < 0.001) and satisfaction (RR: 1.85; 95% CI: 1.31 to 2,61; P < 0.001) were significantly increased compared with sham TENS.ConclusionThis meta-analysis suggests that TENS may serve as an effective and well-tolerated alternative for migraineurs. However, low quality of evidence prevents us from reaching definitive conclusions. Future well-designed RCTs are necessary to confirm and update the findings of this analysis.Systematic review registrationOur PROSPERO protocol registration number: CRD42018085984. Registered 30 January 2018.

Does transcutaneous nerve stimulation have effect on sympathetic skin response?

ObjectiveThis study examined the effects of transcutaneous electrical nerve stimulation (TENS) on the sympathetic nerve system by sympathetic skin response test. MethodsFifty-five healthy volunteers received either: (i) 30minutes TENS (25 participants) (ii) 30minutes sham TENS (30 participants) and SSR test was performed pre- and post-TENS. The mean values of latency and peak-to-peak amplitude of five consecutive SSRs were calculated. ResultsA significant amplitude difference was found between TENS and sham TENS group both in right and left hand (p=0.04, p=0.01, respectively). However there was no significant latancy difference between two groups (p>0.05 ). ConclusionTENS has an inhibitory effect on elicited SNS responses when compared with sham TENS control group.

Transcutaneous electrical nerve stimulation (TENS) for pain management in sickle cell disease

Background Sickle cell disease (SCD), one of the most common inherited disorders, is associated with vaso-occlusive pain episodes and haemolysis leading to recurrent morbidity, hospital admissions and work or school absenteeism. The crises are conventionally treated with opioids, non-opioids and other adjuvants with the risk of developing complications, addictions and drug-seeking behaviour. Different non-pharmacological treatments, such as transcutaneous electrical nerve stimulation (TENS) have been used for managing pain in other painful conditions. Hence, the efficacy of TENS for managing pain in SCD needs to be reviewed. Objectives To assess the benefits and harms of TENS for managing pain in people with SCD who experience pain crises or chronic pain (or both). Search methods We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries and the reference lists of relevant articles and reviews. Date of the last search: 26 Febraury 2020. Selection criteria We included randomised controlled trials (RCTs) and quasi-RCTs, where TENS was evaluated for managing pain in people with SCD. Data collection and analysis Two review authors independently assessed the eligibility of the trials identified by the literature searches according to the inclusion criteria. Two review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using the GRADE guidelines. Main results One double-blind cross-over RCT with 22 participants with SCD (aged 12 to 27 years) was eligible for inclusion. Following stratification into four pain crises severity grades, participants were then randomised to receive TENS or placebo (sham TENS). The trial was concluded after 60 treatment episodes (30 treatment episodes of each treatment group). There is a lack of clarity regarding the trial design and the analysis of the cross-over data. If a participant was allocated to TENS treatment for an episode of pain and subsequently returned with a further episode of a similar degree of pain, they would then receive the sham TENS treatment (cross-over design). For those experiencing a pain episode of a different severity, it is not clear whether they were re-randomised or given the alternate treatment. Reporting and analysis was based on the total number pain events and not on the number of participants. It is unclear how many participants were crossed over from the TENS group to the sham TENS group and vice versa. The trial had a high risk of bias regarding random sequence generation and allocation concealment; an unclear risk regarding the blinding of participants and personnel; and a low risk regarding the blinding of the outcome assessors and selective outcome reporting. The trial was small and of very low quality; furthermore, given the issue with trial design we were unable to quantitatively analyse the data. Therefore, we present only a narrative summary and caution is advised in interpreting the results. In relation to our pre-defined primary outcomes, the included trial did not report pain relief at two to four weeks post intervention. The trial authors reported that no difference was found in the changes in pain ratings (recorded at one hour and four hours post intervention) between the TENS and the placebo groups. In relation to our secondary outcomes, the analgesic usage during the trial also did not show any difference between groups. Given the quality of the evidence, we are uncertain whether TENS improves overall satisfaction as compared to sham TENS. The ability to cope with activities of daily living was not evaluated. Regarding adverse events, although one case of itching was reported in the TENS group, the site and nature of itching was not clearly stated; hence it cannot be clearly attributed to TENS. Also, two participants receiving 'sham' TENS reported a worsening of pain with the intervention. Authors' conclusions Since we have only included one small and very low-quality trial, with a high risk of bias across several domains, we are unable to conclude whether TENS is harmful or beneficial for managing pain in people with SCD. There is a need for a well-designed, adequately-powered, RCT to evaluate the role of TENS in managing pain in people with SCD.

Single-Blinded, Randomized Preliminary Study Evaluating the Effect of Transcutaneous Electrical Nerve Stimulation on Postoperative Pain in Patients with Colles' Fracture.

Transcutaneous electrical nerve stimulation (TENS) has been widely used for pain relief; however, the effect remains controversial. The authors hypothesized that TENS can relieve acute pain. Therefore, a single-blinded, randomized, controlled preliminary study was designed on postoperative pain in patients with Colles' fracture. In total, 36 patients were assigned to a real TENS or sham TENS group (18 patients in each group). TENS (50 Hz, 15 min/day) was applied near the Quchi (LI11) and Waiguan (TE5) surfaces of the operative side continuously for 5 days after surgical treatment. The visual analog scale (VAS) scores did not differ significantly between the real and sham TENS groups before the TENS period, from the first to fifth day after surgical treatment (all p > 0.05), whereas the VAS scores were lower for the real TENS group than for the sham TENS group in the post-TENS period, on the first, third, fourth, and fifth days after surgical treatment (all p ≤ 0.01). TENS might be valuable as a treatment of postoperative pain, but clinicians and researchers should know that it is no different than a treatment with placebo. Especially, since this form of treatment and sham treatment has a great chance of working under the mechanism of the placebo effect due to its single-blindedness.

Transcutaneous Electrical Nerve Stimulation as an Adjunct to Education and Exercise for Knee Osteoarthritis: A Randomized Controlled Trial

To determine the additional effects of transcutaneous electrical nerve stimulation (TENS) for knee osteoarthritis (OA) when combined with a group education and exercise program (knee group). The study was a randomized, sham-controlled clinical trial. Patients referred for physiotherapy with suspected knee OA (confirmed using the American College of Rheumatology clinical criteria) were invited. Exclusion criteria included comorbidities preventing exercise, previous TENS experience, and TENS contraindications. Prospective sample size calculations required 67 participants in each trial arm. A total of 224 participants (mean age 61 years, 37% men) were randomized to 3 arms: TENS and knee group (n = 73), sham TENS and knee group (n = 74), and knee group (n = 77). All patients entered an evidence-based 6-week group education and exercise program (knee group). Active TENS produced a "strong but comfortable" paraesthesia within the painful area and was used as much as needed during the 6-week period. Sham TENS used dummy devices with no electrical output. Blinded assessment took place at baseline and 3, 6, 12, and 24 weeks. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function subscale at 6 weeks. Secondary outcomes included WOMAC pain, stiffness, and total scores; extensor muscle torque; global assessment of change; exercise adherence; and exercise self-efficacy. Data analysis was by intent to treat. All outcomes improved over time (P < 0.05), but there were no differences between trial arms (P > 0.05). All improvements were maintained at 24-week followup. There were no additional benefits of TENS, failing to support its use as a treatment adjunct within this context.

Effects of Electroacupuncture on Stress-Related Symptoms in Medical Students: A Randomised Placebo-Controlled Study

To assess the effects of electroacupuncture (EA) on relieving stress-related symptoms-sleep disorders, anxiety, depression and burnout-in medical students. Eighty-two students were randomised into an EA treatment group (n=30), a sham TENS group (n=18) and an untreated control group (n=34). EA was applied at a continuous frequency of 2 Hz to the limbs, face, ears and scalp for 20 min once a week, over 6-8 weeks. Sham transcutaneous electrical nerve stimulation (TENS) was performed on similar sites for the same number of times in each session and for the same length of time. Outcome measurements included a comparison of the indices obtained by different self-applied questionnaires before and after treatment. The surveys used were the Mini-Sleep Questionnaire (MSQ), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), the Beck Depression and Anxiety Inventories (BDI and BAI) and the Maslach Burnout Inventory-Student Survey (MBI-SS), in addition to the Quality of Life Questionnaire-abbreviated version (WHOQOL-bref). EA significantly improved scores on the MSQ, PSQI, BDI and the cynicism and academic efficacy (AE) dimensions of the MBI-SS in relation to the control. Sleep quality (MSQ) improved from 36.9 (SD 7.6) to 25.0 (5.7) with EA, 37.6 (6.0) to 32.1 (6.9) with sham TENS, and 36.5 (5.9) to 33.6 (6.7) in the controls (p=0.0000). Compared with the sham TENS group, EA significantly reduced scores on the PSQI. Score improvements in the sham TENS group in relation to control group were significant in the MSQ, BDI and AE. In the EA group, the number of students with better scores after intervention was significantly higher for the MSQ, PSQI, ESS and BAI. This only occurred for the MSQ in the sham TENS group and for the MSQ and ESS in the control group. EA significantly reduced stress-related mental symptoms. The improvement obtained by sham TENS compared with the control group confirmed the presence of a placebo effect resulting from the treatment ritual.

Functional Magnetic Resonance Imaging of the Effects of Low-frequency Transcutaneous Electrical Nerve Stimulation on Central Pain Modulation

Transcutaneous electrical nerve stimulation (TENS) is an analgesic current that is used in many acute and chronic painful states. The aim of this study was to investigate central pain modulation by low-frequency TENS. Twenty patients diagnosed with subacromial impingement syndrome of the shoulder were enrolled in the study. Patients were randomized into 2 groups: low-frequency TENS and sham TENS. Painful stimuli were delivered during which functional magnetic resonance imaging scans were performed, both before and after treatment. Ten central regions of interest that were reported to have a role in pain perception were chosen and analyzed bilaterally on functional magnetic resonance images. Perceived pain intensity during painful stimuli was evaluated using visual analog scale (VAS). In the low-frequency TENS group, there was a statistically significant decrease in the perceived pain intensity and pain-specific activation of the contralateral primary sensory cortex, bilateral caudal anterior cingulate cortex, and of the ipsilateral supplementary motor area. There was a statistically significant correlation between the change of VAS value and the change of activity in the contralateral thalamus, prefrontal cortex, and the ipsilateral posterior parietal cortex. In the sham TENS group, there was no significant change in VAS value and activity of regions of interest. We suggest that a 1-session low-frequency TENS may induce analgesic effect through modulation of discriminative, affective, and motor aspects of central pain perception.

The Long‐Term Outcome of Transcutaneous Electrical Nerve Stimulation in the Treatment for Patients with Chronic Pain: A Randomized, Placebo‐Controlled Trial

Transcutaneous electrical nerve stimulation (TENS) is an easy to use analgesic intervention. However, long-term randomized placebo-controlled studies with treatment periods of more than 3 months have not been executed to date. The aim of our study is to explore the long-term (1 year) time course of the treatment effects of TENS compared to placebo (sham TENS). We performed a randomized placebo-controlled trial in patients with chronic pain (165), referred to a multidisciplinary pain center of a university hospital. Main outcome measures are the proportion of patients satisfied with treatment result and willing to continue treatment, pain intensity, pain disability, and perceived health status. Survival analysis of time courses of proportions of satisfied patients revealed no significant differences (P = 0.79; log-rank test) for TENS treatment compared to sham TENS. After 1 year, 30% (24/81) of the patients of the TENS group and 23% (19/82) of the sham TENS group were satisfied with treatment result. These patients experienced a mean overall improvement of 62.7% (n = 43). This effect was not significantly different between both groups. For satisfied patients, there were no differences in pain intensity or disability and perceived health status between the TENS and sham TENS group. Transcutaneous electrical nerve stimulation and sham TENS show similar effects in patients with chronic pain over a period of 1 year. We found support for a long sustained placebo effect.

A Randomized Controlled Trial of Auricular Transcutaneous Electrical Nerve Stimulation for Managing Posthysterectomy Pain

Background. A patient- and assessor-blinded randomized controlled trial was conducted to examine the effectiveness of auricular transcutaneous electrical nerve stimulation (TENS) in relieving posthysterectomy pain. Method. Forty-eight women who had undergone a total abdominal hysterectomy were randomly assigned into three groups (n = 16 each) to receive either (i) auricular TENS to therapeutic points (the true TENS group), (ii) auricular TENS to inappropriate points (the sham TENS group), or (iii) 20 minutes of bed rest with no stimulation (the control group). The intervention was delivered about 24 hours after the operation. A visual analogue scale was used to assess pain while resting (VAS-rest) and upon huffing (VAS-huff) and coughing (VAS-cough), and the peak expiratory flow rate (PEFR) was assessed before and at 0, 15, and 30 minutes after the intervention. Result. As compared to the baseline, only the true TENS group reported a significant reduction in VAS-rest (P = .001), VAS-huff (P = .004), and VAS-cough (P = .001), while no significant reduction in any of the VAS scores was seen in the sham TENS group (all P > .05). In contrast, a small rising trend was observed in the VAS-rest and VAS-huff scores of the control group, while the VAS-cough score remained largely unchanged during the period of the study. A between-group comparison revealed that all three VAS scores of the true TENS group were significantly lower than those of the control group at 15 and 30 minutes after the intervention (all P < .02). No significant between-group difference was observed in PEFR at any point in time. Conclusion. A single session of auricular TENS applied at specific therapeutic points significantly reduced resting (VAS-rest) and movement-evoked pain (VAS-huff, VAS-cough), and the effects lasted for at least 30 minutes after the stimulation. The analgesic effects of auricular TENS appeared to be point specific and could not be attributed to the placebo effect alone. However, auricular TENS did not produce any significant improvement in the performance of PEFR.

Effects of TENS frequency, intensity and stimulation site parameter manipulation on pressure pain thresholds in healthy human subjects

This study evaluated the effects of varying frequency, intensity and stimulation site, of transcutaneous electrical nerve stimulation (TENS) in an experimental model of pain. In a double-blind design 240 volunteers were randomised to one of six experimental TENS groups, a sham TENS or control ( n=30 per group; gender balanced). Two TENS frequencies (110 or 4 Hz) and two intensities (strong but comfortable or highest tolerable) at a fixed pulse duration (200 μs) were applied at three sites relative to the measurement site (segmentally, extrasegmentally or a combination of these), for 30 min. Pressure pain thresholds (PPT) were measured using a pressure algometer, in the first dorsal interosseous muscle, every 10 min, during stimulation and for a further 30 min. The high frequency, high intensity segmental, and combined stimulation groups, showed rapid onset and significant hypoalgesic effects. This effect was sustained for 20 min post-stimulation in the high frequency segmental group. All other TENS intervention groups showed hypoalgesic responses similar to the sham TENS group, and none of these groups reached a clinically significant hypoalgesic level. Conclusions: The role of TENS frequency, intensity and site are pivotal to achieving optimal hypoalgesic effects, during and after stimulation. Clinical applications of these parameter combinations require further investigations.

Sensory stimulation (TENS): effects of parameter manipulation on mechanical pain thresholds in healthy human subjects

Transcutaneous electrical nerve stimulation (TENS) is a popular form of electrostimulation. Despite an extensive research base, there remains no consensus regarding the parameter selection required to achieve maximal hypoalgesic effects. The aim of this double blind, sham-controlled study was to investigate the relative hypoalgesic effects of different TENS parameters (frequency, intensity and stimulation site) upon experimentally induced mechanical pain. Two hundred and forty participants were recruited in order to provide statistical analysis with 80% power at α=0.05. Subjects were randomised to one of the six TENS groups, a control, and a sham TENS group ( n=30, 15 males, 15 females, per group). TENS groups differed in their combinations of stimulation; frequency (4 or 110 Hz), intensity (‘to tolerance’ or ‘strong but comfortable’) and stimulation site (segmental – over the distribution of the radial nerve or, extrasegmental – over acupuncture point ‘gall bladder 34’, or a combination of both segmental and extrasegmental). Pulse duration was fixed at 200 μs. Stimulation was delivered for 30 min and subjects were then monitored for a further 30 min. Mechanical pain threshold (MPT) was measured using a pressure algometer and taken from the first dorsal interosseous muscle of the dominant hand, ipsilateral to the stimulation site. MPT measures were taken, at baseline, and at 10-min intervals for 60 min. Difference scores were analysed using repeated measures and one-way ANOVA and relevant post hoc tests. Low frequency, high intensity, extrasegmental stimulation produced a rapid onset hypoalgesic effect, which increased during the stimulation period ( P<0.0005 control and sham) and was sustained for 30 min post-stimulation ( P<0.0005 control, P=0.024 sham). Whilst high frequency, ‘strong but comfortable’ intensity, segmental stimulation produced comparable hypoalgesic levels during stimulation, this effect was not sustained post-stimulation. Stimulation at a combination of the two sites did not produce any greater hypoalgesic effects. These results may have implications for the clinical use of sensory stimulation.

Can Trials of Physical Treatments Be Blinded?

Therapeutic trials often attempt to "blind" patient and investigator to the true nature of treatments received, reducing the influences of conscious or subconscious prejudices. In drug trials, this is accomplished with placebo tablets, but blinding in trials of physical treatments is more problematic. This issue arose in a clinical trial of transcutaneous electrical nerve stimulation (TENS) for patients with chronic low back pain. Several study design features were incorporated to promote blinding: use of sham TENS units visually identical with real units, exclusion of potential subjects with previous TENS experience, avoidance of a crossover design and use of identical visit frequency, instructions and modifications in electrode placement. Subjects were asked not to discuss treatments with the clinicians who performed outcome assessments. Both patients and clinicians were asked to guess actual treatment assignments at the trial's end. Every patient in the true TENS group believed the unit was functioning properly, but the degree of certainty varied. In the sham TENS group, 84% also believed they had functioning units, but their certainty was significantly less than in the active treatment group. Differences in patient perceptions did not affect compliance, as the two groups had similar dropout rates, appointment compliance, days of TENS use and daily duration of TENS use. Clinicians guessed treatments correctly 61% of the time (as opposed to 50% expected by chance), again suggesting partial success in blinding. These efforts at blinding may partly explain the negative trial results for TENS efficacy. We conclude that complete blinding is difficult to achieve because of sensory difference in treatment and unintended communication between patient and examiner.(ABSTRACT TRUNCATED AT 250 WORDS)