Sham Transcutaneous Electrical Nerve Stimulation Research Articles

Investigating the Effects of Transcutaneous Electrical Nerve Stimulation on Lumbar Fascia Tissue and Lumbar Curvature in Healthy People

Introduction: Transcutaneous electrical nerve stimulation (TENS) is commonly used for pain management. Recent studies have shown that TENS can improve the condition of low back pain by influencing the elastic coefficient of the lumbar fascia and the balance status; however, the effect of TENS on the lumbar fascia of healthy people has not been investigated. Accordingly, this study examines the effect of TENS on the lumbar fascia of healthy people. Materials and Methods: A total of 60 healthy participants in two groups, underwent 10 sessions of conventional TENS intervention. The first group (intervention group) received TENS with an intensity at the tolerance level, and the second group (control group) received sham TENS. Ultrasonography and a spinal mouse device were assessed lumbar fascia thickness and lumbar curvature before and after the TENS. Results: Significant changes were observed after TENS in the intervention group in reducing the lumbar fascia thickness (P=0.006) and increasing the lumbar curvature (P=0.000). Between- group changes after the intervention sessions indicated a significant difference between the lumbar fascia thickness and curvature (P≤0.003). Conclusion: TENS in healthy people can lead to a decrease in the thickness of the lumbar fascia and improve lumbar curvature. Also, a strong correlation was found between lumbar fascia thickness reduction and increased lumbar curvature.

Effectiveness of Neuromuscular Taping on Balance, Proprioception, Pain, and Nerve Conduction Parameters in Patients with Diabetic Peripheral Neuropathy: A Two-Group Pretest–Posttest Randomized Sham-Controlled Trial: A Pilot Study

Abstract Aim: Neuromuscular Taping (NMT) is the application of elastic adhesive tape to the skin without any tension in it. NMT creates wrinkles on the surface of the skin to help stretch the skin passively and this elongation force assists in muscle contraction and relaxation. Therefore, this study aimed to assess the effectiveness of NMT in the improvement of sensorimotor complications following diabetic peripheral neuropathy (DPN). Setting and Design: A randomized controlled trial performed at a tertiary health care center. Materials and Methods: A total of 20 participants were recruited and were divided into two groups: The experimental group (EG; N = 10) and the control group (CG; N = 10). Eight weeks of physiotherapy intervention including NMT on bilateral tibialis anterior, tibialis posterior, peroneus longus muscles, transverse arch of the foot, and transcutaneous electrical nerve stimulation (TENS) on the course of bilateral tibial and peroneal nerves for EG. CG received sham taping and TENS as an EG group. The patients were assessed for pre- and post-intervention using the outcomes: Leeds Assessment of Neuropathic Signs and Symptoms and nerve conduction velocity of tibial, peroneal, and sural nerves and H-reflex, Berg Balance Scale, and Pedalo-Sensamove Mini Board. Results: The results revealed that both the groups showed significant improvements in all variables except for the H-reflex of the right and left sides at P > 0.05. EG showed more clinical and symptomatic improvement compared with CG. In EG, most of the variables showed moderate to large effect sizes ranging from 0.66 to 0.97 except for bilateral H-reflex; ranging from 0.15 to 0.33. Conclusion: This study concludes that NMT can be a trustworthy approach to treating DPN.

Comparative Analysis of High-Frequency and Low-Frequency Transcutaneous Electrical Stimulation of the Right Median Nerve in the Regression of Clinical and Neurophysiological Manifestations of Generalized Anxiety Disorder.

Background/Objectives: The anxiolytic effect of transcutaneous electrical nerve stimulation (TENS) is associated with the activation of endogenous inhibitory mechanisms in the central nervous system. Both low-frequency, high-amplitude TENS (LF-TENS) and high-frequency, low-amplitude TENS (HF-TENS) are capable of activating opioid, GABA, serotonin, muscarinic, and cannabinoid receptors. However, there has been no comparative analysis of the effectiveness of HF-TENS and LF-TENS in the treatment of GAD. The purpose of our research was to study the effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of patients with GAD compared with sham TENS. Methods: The effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of GAD was studied using Generalized Anxiety Disorder 7-item scale (GAD-7) and the Hamilton Anxiety Rating Scale (HAM-A). 40 patients underwent sham TENS, 40 patients passed HF-TENS (50 Hz-50 μs-sensory response) and 41 patients completed LF -TENS (1 Hz-200 μs-motor response) for 30 days daily. After completion of treatment, half of the patients received weekly maintenance therapy for 6 months. Electroencephalography was performed before and after treatment. Results: Our study showed that a significant reduction in the clinical symptoms of GAD as assessed by GAD-7 and HAM-A was observed after HF-TENS and LF-TENS by an average of 42.4%, and after sham stimulation only by 13.5% for at least 2 months after the end of treatment. However, LF-TENS turned out to be superior in effectiveness to HF-TENS by 51% and only on electroencephalography leads to an increase in PSD for the alpha rhythm in the occipital regions by 24% and a decrease in PSD for the beta I rhythm in the temporal and frontal regions by 28%. The prolonged effect of HF-TENS and LF-TENS was maintained without negative dynamics when TENS treatment was continued weekly throughout the entire six-month observation period. Conclusions: A prolonged anxiolytic effect of direct TENS of the right median nerve has been proven with greater regression of clinical and neurophysiological manifestations of GAD after LF-TENS compared to HF-TENS. Minimal side effects, low cost, safety, and simplicity of TENS procedures are appropriate as a home treatment modality.

A transcutaneous electrical nerve stimulation device for the relief of neuropathic pain in NMOSD: A randomized, double-blind, sham-controlled trial.

Individuals with neuromyelitis optica spectrum disorder (NMOSD) often suffer from severe, disabling, and treatment-refractory neuropathic pain. Transcutaneous electrical nerve stimulation (TENS) therapy is a non-invasive, pain-modifying device. To determine whether TENS therapy is safe, tolerable, and effective for neuropathic pain in patients with NMOSD. We conducted a four-week, randomized, double-blind, sham-controlled, remote trial of TENS in patients with NMOSD who have neuropathic pain, followed by a 12-week open-label extension period. The difference in the Numeric Rating Scale current pain scores between 0 weeks and 4 weeks was the primary outcome measure. Forty-six patients (23 per arm) were enrolled in this trial, of which 40 were included in the primary analysis (four in the intervention arm and two in the sham arm withdrew prior to assessment of the primary outcome). Both the sham and intervention arms demonstrated significant decreases in average pain, worst pain, and current pain rating between baseline and 4 weeks, but there was no significant difference between the two arms. In conclusion, there was no demonstrated benefit of TENS over sham TENS treatment, however, both arms demonstrated significant decreases in reported pain between baseline and 4 weeks. This trial is registered with ClinicalTrials.gov, NCT04614454.

Transcutaneous electrical nerve stimulation (TENS) versus sham TENS in adult ED patients with abdominal pain: A clinical trial

ObjectiveThere is a growing consensus that the risks of current pharmacologic analgesics warrant consideration of alternative modalities for acute and chronic pain control. The objective of this study was to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in adult emergency department (ED) patients presenting with abdominal pain. MethodsWe conducted a patient and observer blinded randomized controlled trial comparing TENS to sham TENS. The study was conducted at a large suburban academic ED. Patients with abdominal pain and a verbal numeric pain scale (VNS) of 5 or greater were randomized to TENS or sham TENS applied via 4 skin pads, one in each abdominal quadrant for 30 min. The primary outcome was change in pain scores 30 min after the intervention. Our study had 80% power to detect a between group difference of 1.5 points on the VNS. Results81 patients were randomized to TENS (n = 41) or sham TENS (n = 40). Groups were similar in baseline characteristics. The mean (SD) reductions in pain scores were 1.9 (2.1) and 1.7 (2.6) in patients treated with TENS and sham TENS respectively (P = 0.81). Use of rescue medications in patients with treated with TENS and sham TENS was similar (49 vs 55% respectively, P = 0.66). ConclusionsApplication of TENS to the abdominal wall did not result in more effective pain relief than sham TENS in adult ED patients with abdominal pain.

Baseline heart rate variability predicts placebo hypoalgesia in men, but not women.

Placebo hypoalgesic effects vary greatly across individuals, making them challenging to control for in clinical trials and difficult to use in treatment. We investigated the potential of resting vagally-mediated heart rate variability (vmHRV) to help predict the magnitude of placebo responsiveness. In two independent studies (total N = 77), we administered a placebo paradigm after measuring baseline HRV. In Study I, we delivered heat pain to the forearm, on skin patches treated with "real" and "control" cream (identical inactive creams). In Study II, electrical pulses to the forearm were modulated by sham transcutaneous electrical nerve stimulation. We combined data from both studies to evaluate the relationship between vagally-mediated HRV (vmHRV) parameters and the placebo response size, while also assessing sex differences in this relationship. This revealed a positive association between vmHRV and the degree of pain relief, and this effect was driven by men. These results not only reveal new insights into the (sex-specific) mechanisms of placebo hypoalgesia, but also suggest that measuring vmHRV may be helpful in predicting placebo responsiveness. Given that placebo hypoalgesic effects contribute substantially to treatment outcomes, such a non-invasive and easily obtained predictor would be valuable in the context of personalized medicine.

Nocebo Hyperalgesia in Patients With Fibromyalgia and Healthy Controls: An Experimental Investigation of Conditioning and Extinction Processes at Baseline and 1-Month Follow-up

Nocebo effects are adverse treatment outcomes that are not ascribed to active treatment components. Potentially, their magnitude might be higher in patients with chronic pain compared to healthy controls since patients likely experience treatment failure more frequently. The current study investigated group differences in the induction and extinction of nocebo effects on pressure pain at baseline (N = 69) and 1-month follow-up (N = 56) in female patients with fibromyalgia and matched healthy controls. Nocebo effects were first experimentally induced via classical conditioning combined with instructions on the pain-increasing function of a sham transcutaneous electrical nerve stimulation device, then decreased via extinction. One month later, the same procedures were repeated to explore their stability. Results suggest that nocebo effects were induced in the healthy control group during baseline and follow-up. In the patient group, nocebo effects were only induced during follow-up, without clear group differences. Extinction was only observed during baseline in the healthy control group. Further comparisons of nocebo effects and extinction indicated no significant changes across sessions, possibly suggesting their overall magnitudes were stable over time and across groups. In conclusion, contrary to our expectations, patients with fibromyalgia did not have stronger nocebo hyperalgesia; instead, they might be less responsive to nocebo manipulations than healthy controls. PerspectiveThe current study is the first to investigate group differences in experimentally manipulated nocebo hyperalgesia between chronic pain and healthy populations at baseline and 1-month follow-up. Since nocebo effects are common in clinical settings, their investigation in different populations is essential to explain and minimize their adverse effects during treatment.

Addition of tDCS and TENS to an education and exercise program in subjects with knee osteoarthritis: A study protocol.

Knee osteoarthritis often leads to chronic pain that frequently becomes disabling.Osteoarthritis has been linked to maladaptive plasticity in the brain, which can contribute to chronic pain. Therapies including neuromodulation and peripheral electrical stimulation are used to counteract the maladaptive plasticity of the brain. To determine the efficacy of the addition of tDCS and TENS to an education and exercise program in reducing pain. Over a 2-week study period, 60 participants will complete an exercise and educational intervention. Eligible participants accepting to participate will be subsequently randomized into one of the three treatment groups: 1) Active Transcranial Direct Current Stimulation (tDCS) and active Transcutaneous Electrical Nerve Stimulation (TENS); 2) Active tDCS and sham TENS; 3) Sham tDCS and sham TENS. The primary outcome will be subjective pain intensity. quality of life, physical function, central sensitization, and pain adjuvants (uncertainty, catastrophizing kinesiophobia, adverse events). This clinical trial will provide data on the effect that the addition of tDCS and/or TENS to an education and exercise program may have to counteract maladaptive plastic changes and improve the benefits of exercises, and whether the combination of both neuromodulator techniques may have a higher magnitude of effect.

Higher Pain Sensitivity Predicts Efficacy of a Wearable Transcutaneous Electrical Nerve Stimulation Device for Persons With Fibromyalgia: A Randomized Double-Blind Sham-Controlled Trial

ObjectivesThis study investigated the efficacy of a transcutaneous electrical nerve stimulation (TENS) device (Quell®) for persons with symptoms due to fibromyalgia (FM). Materials and MethodsOne hundred nineteen (N = 119) subjects were randomly assigned to use an active (N = 62) or sham (N = 57) TENS for three months. All subjects completed baseline questionnaires and were administered quantitative sensory testing (QST). Subjects completed the Patients' Global Impression of Change (PGIC, primary outcome measure) and other mailed questionnaires (secondary outcome measures) at six weeks and three months. ResultsThe subjects averaged 50.4 ± 13.5 years of age, 93.3% were female, and 79.8% were Caucasian. Most showed benefit from using the TENS, but no differences between groups were found on the primary outcome measure after three months (active 3.87 ± 1.85, sham 3.73 ± 1.80, 95% confidence interval [CI] [−0.60, 0.88], p = 0.707). Those with more hypersensitivity showed most improvement on the PGIC at six weeks (0.22, 95% CI [0.01, 0.43], p = 0.042) and three months (0.20, 95% CI [0.00, 0.41], p = 0.049) and among those with higher sensitivity based on QST, the active TENS group showed the most benefit with TENS compared with the sham treatment (1.20, 95% CI [0.22, 2.18], p = 0.017). No TENS-related serious adverse events were reported. Subjects in the sham group correctly identified their treatment 87.5% of the time, while, surprisingly, subjects in the active group correctly identified their treatment only 17.4% of the time. ConclusionThis study found no differences between those who were exposed to maximal-frequency active stimulation or minimal-frequency sham stimulation from a wearable TENS in reducing FM-related symptoms. However, those with greater hypersensitivity showed most benefit from TENS. Additional studies to help determine the role individual differences play in the use of TENS in managing FM-related symptoms are needed.

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.

Shoulder transcutaneous electric nerve stimulation decreases heart rate via potentiating vagal tone

By enhancing vagal activity, auricle transcutaneous electric nerve stimulation (TENS) is developed as a non-invasive therapy for heart failure. Nevertheless, though shoulder TENS used for treating adhesive capsulitis could affect vagal tone, its potential impact on heart functions remains unclear. In this study, electrocardiogram (ECG) and heart rate (HR) of subjects in response to sham, right-sided, or left-sided shoulder TENS (TENS-S, TENS-R, and TENS-L, respectively; 5 min) were recorded and analyzed. During the stimulation period, TENS-R constantly and TENS-L transiently decreased the HR of subjects; both TENS-R and TENS-L increased powers of the low- and high-frequency spectra. While TENS-R exhibiting no effect, TENS-L increased the ratio of low/high-frequency power spectrum indicating TENS-R decreased the HR through potentiating cardiac vagal tone. Collectively, these results suggest TENS could be an early and non-invasive therapy for heart failure patients before considering implant devices or devices are not feasible; moreover, therapists/physicians need to carefully monitor the potential adverse events during treatment for patient safety.Trial registration: The study protocol was registered in ClinicalTrials.gov (NCT03982472; 11/06/2019).

Acupuncture-like versus conventional transcutaneous electrical nerve stimulation in the management of active myofascial trigger points: A randomized controlled trial

PurposeMyofascial pain syndrome (MPS) is one of the most common causes of chronic musculoskeletal pain. The transcutaneous electrical nerve stimulation (TENS) is a non-expensive, safe, feasible modality, used recently for the treatment of MPS with promising but limited results. The purpose of this study was to determine the efficacy of acupuncture-like TENS (AL-TENS) vs conventional TENS (C-TENS) in the treatment of active myofascial trigger points. MethodsThis randomized controlled trial study was carried out with 60 consecutive patients with active trapezius trigger points referred to Physical Medicine and Rehabilitation Clinic. Participants randomly assigned to receive AL-TENS, C-TENS or sham TENS (S-TENS). The Visual Analogue Scale (VAS), Pressure Pain Thresholds (PPTs), and neck range of motion (ROM) were measured at baseline, after the first treatment sessions, after the final treatment session, and 3 months after the end of the last treatment session. Patients function was evaluated by Disabilities of the Arm, Shoulder, and Hand (DASH) at baseline, after the final treatment sessions, and 3 months after the end of intervention. ResultsThe interaction effect of time and group was significantly different when evaluating VAS (df = 4.65, F = 2.50, p = 0.038) and DASH (df = 2.63, F = 7.25, p < 0.001) in favor of active groups, as well as neck total lateral bending in favor of AL-TENS group compared other two groups (df = 4.16, F = 5.23, p = 0.001). Both VAS and DASH improved significantly at all follow-ups in AL-TENS and C-TENS groups. Of note, significant immediate improvement in all outcomes was observed only with AL-TENS. ConclusionsAccording to the present study, both AL-TENS and C-TENS were superior to placebo in pain reduction and functional improvement. Although both TENS techniques have similar efficiency on pain reduction, functional and pain perception improvement, the AL-TENS was the superior approach when evaluating neck lateral bending ROM.

Effectiveness of transcutaneous electrical nerve stimulation as an adjunct to selected physical therapy exercise program on male patients with pudendal neuralgia: A randomized controlled trial

Objective: To assess the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) combined with selected physical therapy exercise program on male patients with pudendal neuralgia. Design: A double-blinded randomized controlled study. Setting: Out-patient setting. Participants: Fifty-two male participants with pudendal neuralgia (30–50 years) were allocated randomly into two groups; study and control. The same physical therapy exercises were applied to all participants, plus the same prescribed analgesic medication (Etodolac). Participants in the study group received additional TENS and sham TENS were given to those in control group. Intervention: Intervention lasted for 12 weeks, three sessions per week (60 minutes/session). Outcome measures: Numerical pain rating scale and daily Etodolac intake dose were measured before and after intervention. Results: Statistically significant differences were detected in numerical pain rating scale and daily Etodolac intake in favor of the study group (P < 0.05). After 12 weeks of intervention, the mean ± SD for numerical pain rating scale and daily Etodolac intake were 4.25 ± 1.9 and 259.25 ± 84.4 mg, in the study group, and 6.22 ± 2.22 and 355.55 ± 93.36 mg in the control group, respectively. The mean difference (95% CI) for numerical pain rating scale and daily Etodolac intake was −1.97 (−3.09: −0.83) and −96.3 (−144.9: −47.69), between groups post treatment, respectively. Conclusion: Adding TENS to physical therapy exercise program is more effective than physical therapy program alone in improving pain in male patients with pudendal neuralgia as measured by numerical pain rating scale and daily analgesic intake dose.

Effect of transcutaneous electrical nerve stimulation on quality of recovery and pain after abdominal hysterectomy.

Background and Aims:Transcutaneous electrical nerve stimulation (TENS) is a noninvasive complementary therapy for postoperative pain management. The effect of TENS on quality of recovery (QoR) and pain treatment in the early postoperative period is not well documented. The aim of this study was to evaluate the effect of TENS on postoperative QoR and pain in patients who had undergone a total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH + BSO).Material and Methods:Fifty-two patients were randomized into two groups: control (sham TENS treatment) and TENS (TENS treatment). QoR, dynamic pain, and static pain were evaluated after surgery.Results:The QoR score was significantly higher in the TENS group as compared with that in the control group (P = 0.029). Pain scores during coughing (dynamic pain) were significantly less in TENS group compared to control group (P <0.001). However, there was no between-group difference in pain scores at rest (static pain) or total analgesic consumption (P = 0.63 or P = 0.83, respectively).Conclusion:TENS may be a valuable tool to improve patients' QoR and dynamic pain scores after TAH + BSO.

Analgesic Tolerance Development during Repetitive Electric Stimulations Is Associated with Changes in the Expression of Activated Microglia in Rats with Osteoarthritis.

Electric stimulation is used for managing osteoarthritic (OA) pain; however, little is known about the development of analgesic tolerance during repeated stimulations and the relation of spinal microglia with OA pain. We investigated the changes in the analgesic effects of repeated electric stimulations and the relation between the development of analgesic tolerance and spinal microglial expression in rats with OA. To induce OA, monosodium iodoacetate was injected into the synovial space of the right knee joint of the rats (n = 185). Repeated high frequency, low frequency, or sham transcutaneous electric nerve stimulation (TENS) was performed to the ipsilateral knee joint for 20 min in rats with OA (n = 45). Minocycline or minocycline plus TENS (HF, LF, or sham) was treated in OA rats with repeated TENS-induced tolerance (n = 135). Immunohistochemistry of the microglia in the L3–L5 spinal segments was performed. Knee joint pain during passive movement of the knee joint were quantified using the knee-bend score and the proportion of activated microglia was calculated as primary variables. Paw withdrawal threshold (hypersensitivity to mechanical stimuli) was assessed and the resting and activated microglia were counted as secondary variables. Repeated applications decreased the analgesic effect of TENS on OA pain and failed to reduce the expression of activated microglia in the spinal cord. However, spinal microglial inhibition by minocycline restored the analgesic effect of TENS on OA pain in TENS-tolerant OA rats. TENS combined with minocycline treatment improved knee joint pain and mechanical hypersensitivity in TENS-tolerant OA rats, and inhibited the expression of activated microglia in the spinal cord. These results suggest a possible relationship between repetitive electric stimulation-induced analgesic tolerance for OA pain control and changes in microglia activation.

Supraspinal neural mechanisms of the analgesic effect produced by transcutaneous electrical nerve stimulation.

Although the analgesic effects of conventional transcutaneous electrical nerve stimulation (TENS) and acupuncture-like TENS are evident, their respective neural mechanisms in humans remain controversial. To elucidate and compare the supraspinal neural mechanisms of the analgesic effects produced by conventional TENS (high frequency and low intensity) and acupuncture-like TENS (low frequency and high intensity), we employed a between-subject sham-controlled experimental design with conventional, acupuncture-like, and sham TENS in 60 healthy human volunteers. In addition to assessing the TENS-induced changes of subjective ratings of perceived pain, we examined the TENS associated brainstem activities (fractional amplitude of low frequency fluctuations, fALFF) and their corresponding resting state functional connectivity (RSFC) with higher-order brain areas using functional magnetic resonance imaging. The analgesic effect of conventional TENS was only detected in the forearm that received TENS, coupled with decreased pons activity and RSFC between pons and contralateral primary somatosensory cortex. In contrast, acupuncture-like TENS produced a spatially diffuse analgesic effect, coupled with increased activities in both subnucleus reticularis dorsalis (SRD) and rostral ventromedial medulla (RVM), and decreased RSFC between SRD and medial frontal regions as well as between SRD and lingual gyrus. To sum up, our data demonstrated that conventional TENS and acupuncture-like TENS have different analgesic effects, which are mediated by different supraspinal neural mechanisms.

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