Local field potential-based brain-machine interface to inhibit epileptic seizures by spinal cord electrical stimulation.

Objective.This study proposes a closed-loop brain-machine interface (BMI) based on spinal cord stimulation to inhibit epileptic seizures, applying a semi-supervised machine learning approach that learns from Local Field Potential (LFP) patterns acquired on the pre-ictal (preceding the seizure) condition.Approach.LFP epochs from the hippocampus and motor cortex are band-pass filtered from 1 to 13 Hz, to obtain the time-frequency representation using the continuous Wavelet transform, and successively calculate the phase lock values (PLV). As a novelty, theZ-score-based PLV normalization using both modifiedk-means and Davies-Bouldin's measure for clustering is proposed here. Consequently, a generic seizure's detector is calibrated for detecting seizures on the normalized PLV, and enables the spinal cord stimulation for periods of 30 s in a closed-loop, while the BMI system detects seizure events. To calibrate the proposed BMI, a dataset with LFP signals recorded on five Wistar rats during basal state and epileptic crisis was used. The epileptic crisis was induced by injecting pentylenetetrazol (PTZ). Afterwards, two experiments without/with our BMI were carried out, inducing epileptic crisis by PTZ in Wistar rats.Main results.Stronger seizure events of high LFP amplitudes and long time periods were observed in the rat, when the BMI system was not used. In contrast, short-time seizure events of relative low intensity were observed in the rat, using the proposed BMI. The proposed system detected on unseen data the synchronized seizure activity in the hippocampus and motor cortex, provided stimulation appropriately, and consequently decreased seizure symptoms.Significance.Low-frequency LFP signals from the hippocampus and motor cortex, and cord spinal stimulation can be used to develop accurate closed-loop BMIs for early epileptic seizures inhibition, as an alternative treatment.

Motor Point as an Alternative to Femoral Nerve Stimulation for the Assessment of Quadriceps Muscle Inhibition in Healthy Women.

CONTEXT: The evaluation of quadriceps muscle inhibition with the interpolated twitch technique is usually performed by stimulating the femoral nerve (FN). However, there are some problems related to the use of this stimulation site, which may be partially overcome by delivering the stimulation over the motor point (MP). This study sought to compare MP to FN stimulation at different joint angles for the evaluation of quadriceps muscle inhibition, resting peak torque, and discomfort in healthy women. DESIGN: Cross-sectional study. METHODS: Sixteen healthy women (age: 28 [4] y; body mass: 60 [5] kg; height: 162 [5] cm) participated in this study. Supramaximal paired stimuli were delivered to the FN and to the rectus femoris MP before and during maximal voluntary contractions at different knee angles (15°, 30°, 45°, 60°, and 90° of knee flexion) to assess muscle inhibition and resting peak torque. Discomfort was also recorded for each stimulation site and knee angle. RESULTS: Muscle inhibition was similar between the 2 stimulation sites (P > .05) and was higher at 45° than at 90° (P = .03). MP stimulation evoked lower resting peak torque at 30° (P = .004), 60° (P = .006), and 90° (P = .006) and higher discomfort at 30° (P = .008) and 90° (P = .027) compared to FN stimulation. CONCLUSIONS: Despite lower resting peak torque and higher discomfort at some angles, MP stimulation provided similar muscle inhibition to FN stimulation at all knee angles and is therefore a valid method to evaluate quadriceps muscle inhibition in healthy women. MP stimulation can be used as an alternative to FN stimulation for the evaluation of quadriceps muscle inhibition with no added discomfort at the angles where muscle inhibition is the highest.

Letter to the editor: "Effect of electrical stimulation on the fusion rate after spinal surgery: a systematic review and meta-analysis".

This letter provides feedback on the article Effect of electrical stimulation on the fusion rate after spinal surgery: a systematic review and meta-analysis. The study highlights the clinical efficacy of electrical stimulation (ES) in enhancing fusion rates post-surgery. Future research should focus on identifying optimal ES parameters, long-term safety profiles, and its personalized application based on genetic and metabolic factors. Additionally, exploring the combination of ES with other regenerative therapies and evaluating its cost-effectiveness could further improve clinical outcomes.

Electrodiagnosis for mitigating false-negative non-responsiveness in electrical evoked contractions: A case series exploring probable polyneuromyopathy induced by nonuse.

INTRODUCTION: The revised international standards for neurological classification of spinal cord injury (ISNCSCI) have facilitated the documentation of non-spinal cord injury-related impairments, such as chronic peripheral nerve injuries and muscle weakness due to immobility. This advancement addresses potential biases in muscle strength examinations. Utilizing electrically evoked contractions from paralyzed muscles, enhanced by electrodiagnosis, holds promise in identifying false-negative diagnoses of non-responsiveness to neuromuscular electrical stimulation. This concept prompts the exploration of polyneuromyopathy arising from nonuse in paralyzed muscles. CASE SERIES PRESENTATION: To substantiate our hypothesis, we recruited nine participants for a case series aimed at elucidating the potential benefits of incorporating the stimulus electrodiagnostic test (SET) to mitigate non-responsiveness during preparation for functional electrical stimulation (FES)-assisted cycling. In our convenience sample (n = 5), we conducted neurological mapping based on ISNCSCI and applied SET on the quadriceps. The SET guided optimal dosimetry for evoking contractions and revealed responses similar to those observed in peripheral neuropathies, with α coefficients equal to or lower than 2.00. This observation is likely attributable to nonuse of paralyzed muscles, indicative of an ongoing polyneuropathy in individuals with chronic spinal cord injury (SCI). DISCUSSION: Among the nine initially recruited subjects, seven exhibited responsiveness to neuromuscular electrical stimulation (78% responsiveness), with two participants excluded based on exclusion criteria. In the final five reported cases, all displayed α coefficient values indicating impaired neuromuscular accommodation, and one presented no α coefficient within the normal range. The inclusion of electrodiagnosis appears effective in averting non-responsiveness, suggesting the presence of ongoing polyneuropathies in paralyzed muscles.

Basal release of 6-cyanodopamine from rat isolated vas deferens and its role on the tissue contractility.

6-Cyanodopamine is a novel catecholamine released from rabbit isolated heart. However, it is not known whether this catecholamine presents any biological activity. Here, it was evaluated whether 6-cyanodopamine (6-CYD) is released from rat vas deferens and its effect on this tissue contractility. Basal release of 6-CYD, 6-nitrodopamine (6-ND), 6-bromodopamine, 6-nitrodopa, and 6-nitroadrenaline from vas deferens were quantified by LC-MS/MS. Electric-field stimulation (EFS) and concentration-response curves to noradrenaline, adrenaline, and dopamine of the rat isolated epididymal vas deferens (RIEVD) were performed in the absence and presence of 6-CYD and /or 6-ND. Expression of tyrosine hydroxylase was assessed by immunohistochemistry. The rat isolated vas deferens released significant amounts of both 6-CYD and 6-ND. The voltage-gated sodium channel blocker tetrodotoxin had no effect on the release of 6-CYD, but it virtually abolished 6-ND release. 6-CYD alone exhibited a negligible RIEVD contractile activity; however, at 10 nM, 6-CYD significantly potentiated the noradrenaline- and EFS-induced RIEVD contractions, whereas at 10 and 100 nM, it also significantly potentiated the adrenaline- and dopamine-induced contractions. The potentiation of noradrenaline- and adrenaline-induced contractions by 6-CYD was unaffected by tetrodotoxin. Co-incubation of 6-CYD (100 pM) with 6-ND (10 pM) caused a significant leftward shift and increased the maximal contractile responses to noradrenaline, even in the presence of tetrodotoxin. Immunohistochemistry revealed the presence of tyrosine hydroxylase in both epithelial cell cytoplasm of the mucosae and nerve fibers of RIEVD. The identification of epithelium-derived 6-CYD and its remarkable synergism with catecholamines indicate that epithelial cells may regulate vas deferens smooth muscle contractility.

Effect of muscle length on maximum evoked torque, discomfort, contraction fatigue, and strength adaptations during electrical stimulation in adult populations: A systematic review.

Neuromuscular electrical stimulation (NMES) can improve physical function in different populations. NMES-related outcomes may be influenced by muscle length (i.e., joint angle), a modulator of the force generation capacity of muscle fibers. Nevertheless, to date, there is no comprehensive synthesis of the available scientific evidence regarding the optimal joint angle for maximizing the effectiveness of NMES. We performed a systematic review to investigate the effect of muscle length on NMES-induced torque, discomfort, contraction fatigue, and strength training adaptations in healthy and clinical adult populations (PROSPERO: CRD42022332965). We conducted searches across seven electronic databases: PUBMED, Web of Science, EMBASE, PEDro, BIREME, SCIELO, and Cochrane, over the period from June 2022 to October 2023, without restricting the publication year. We included cross-sectional and longitudinal studies that used NMES as an intervention or assessment tool for comparing muscle lengths in adult populations. We excluded studies on vocalization, respiratory, or pelvic floor muscles. Data extraction was performed via a standardized form to gather information on participants, interventions, and outcomes. Risk of bias was assessed using the Revised Cochrane risk-of-bias tool for cross-over trials and the Physiotherapy Evidence Database scale. Out of the 1185 articles retrieved through our search strategy, we included 36 studies in our analysis, that included 448 healthy young participants (age: 19-40 years) in order to investigate maximum evoked torque (n = 268), contraction fatigability (n = 87), discomfort (n = 82), and muscle strengthening (n = 22), as well as six participants with spinal cord injuries, and 15 healthy older participants. Meta-analyses were possible for comparing maximal evoked torque according to quadriceps muscle length through knee joint angle. At optimal muscle length 50° - 70° of knee flexion, where 0° is full extension), there was greater evoked torque during nerve stimulation compared to very short (0 - 30°) (p<0.001, CI 95%: -2.03, -1.15 for muscle belly stimulation, and -3.54, -1.16 for femoral nerve stimulation), short (31° - 49°) (p = 0.007, CI 95%: -1.58, -0.25), and long (71° - 90°) (p<0.001, CI 95%: 0.29, 1.02) muscle lengths. At long muscle lengths, NMES evoked greater torque than very short (p<0.001, CI 95%: -2.50, -0.67) and short (p = 0.04, CI 95%: -2.22, -0.06) lengths. The shortest quadriceps length generated the highest perceived discomfort for a given current amplitude. The amount of contraction fatigability was greater when muscle length allowed greater torque generation in the pre-fatigue condition. Strength gains were greater for a protocol at the optimal muscle length than for short muscle length. The quality of evidence was very high for most comparisons for evoked torque. However, further studies are necessary to achieve certainty for the other outcomes. Optimal muscle length should be considered the primary choice during NMES interventions, as it promotes higher levels of force production and may facilitate the preservation/gain in muscle force and mass, with reduced discomfort. However, a longer than optimal muscle length may also be used, due to possible muscle lengthening at high evoked tension. Thorough understanding of these physiological principles is imperative for the appropriate prescription of NMES for healthy and clinical populations.

Effect of tetanic stimulation prior to train-of-four monitoring on the time to muscle response stabilization with neuromuscular blockade with rocuronium in patients aged 60 to 80 years: A prospective randomized controlled trial.

PURPOSE: To determine the effect of tetanic stimulation on the time to achieve stabilization of the T1 height, by acceleromyography train-of-four (TOF) ratio monitoring, in patients aged 60 to 80 years. METHODS: Randomized, prospective, single-blind, controlled trial in patients aged 60 to 80 years undergoing elective surgery under general anesthesia in two university hospitals in Brazil between December 2019 and March 2022. This trial was performed in accordance with the principles of the Helsinki Declaration and the guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents II. Participants were randomly allocated by computer-generated numbers to receive tetanic stimulation (intervention group, n = 25) or not receive tetanic stimulation (control group, n = 25) to achieve T1 height stabilization on TOF ratio monitoring. The primary endpoint was to evaluate the effect of tetanic stimulation on the time to achieve stabilization of the T1 height. We also evaluated the effect on the onset time of rocuronium and time to recover from neuromuscular blockade with a single dose of rocuronium 0.6 mg.kg-1 with spontaneous recovery. RESULTS: There was no statistically significant difference between the groups in the time to T1 height stabilization (intervention: 4.3 [2.0-8.0] min; control: 5.8 [2.0-10.5] min; p = 0.202), onset time of the neuromuscular blocking agent (intervention: 1.9 [±0.7] min; control: 2.2 [±1.0] min; p = 0.219), or neuromuscular blockade recovery times to normalized TOF values of 0.7 (intervention: 106.1 [±37.2] min; control: 91.7 [±27.5] min; p = 0.295), 0.8 (intervention: 114.3 [±40.1] min; control: 97.8 [±28.9] min; p = 0.225), 0.9 (intervention: 126.5 [±44.0] min; control: 106.9 [±30.6] min; p = 0.153), and 1.0 (intervention: 138.3 [±43.4] min; control: 123.8 [±43.5] min; p = 0.425). CONCLUSION: The results of this study suggest that the recommendation to use tetanic stimulation to shorten the time to T1 height stabilization in neuromuscular monitoring did not alter the stabilization time of the T1 twitch or the pharmacodynamics of neuromuscular blockade with rocuronium in patients aged 60 to 80 years.

Effects of upper limbs' neuromuscular electrical stimulation (NMES) superimposed to voluntary contraction added to a protocol of intradialytic leg cycle ergometer exercise, in muscle strength, functional capacity and quality of life of adult patients with CKD: a randomized clinical trial protocol.

OBJECTIVE: To investigate the effects of unilateral upper limbs' (ULM) neuromuscular electrical stimulation (NMES) superimposed on a voluntary contraction added to a protocol of intradialytic leg cycle ergometer exercise on muscle strength, functional capacity and quality of life of adult patients with chronic kidney disease (CKD). METHODS: This randomized controlled clinical trial will be carried out at a Brazilian University Hospital. The patients will be evaluated and randomly allocated to an intervention group (i.e., unilateral NMES on the upper limb without hemodialysis fistula for 20 min and leg cycle ergometer for 30 min) or a control group (i.e., unilateral NMES-Sham on the upper limb without hemodialysis fistula for 20 min and leg cycle ergometer for 30 min). The patients will be treated for 8 weeks, with three weekly treatment sessions totaling 24 sessions. MEASUREMENTS: ULM muscle strength, functional capacity, quality of life and also the feasibility, safety and patient adherence to the exercise protocol. All physical measurements will be collected by trained researchers before treatment (week 0) and at the end of treatment (week 9), always in the second hemodialysis session of the week. It will be used in an intention-to-treat analysis. RESULTS/CONCLUSIONS: The outcomes of this clinical trial protocol may help to know the possible benefits of unilateral ULM' NMES superimposed on a voluntary contraction added to a protocol of leg cycle ergometer for patients with CKD and to aid clinical decisions about future implementation or not of this technique (NMES) in intradialytic physical training programs.

Ischemic preconditioning increases spinal excitability and voluntary activation during maximal plantar flexion contractions in men.

The enigmatic benefits of acute limb ischemic preconditioning (IP) in enhancing muscle force and exercise performance have intrigued researchers. This study sought to unravel the underlying mechanisms, focusing on increased neural drive and the role of spinal excitability while excluding peripheral factors. Soleus Hoffmann (H)-reflex /M-wave recruitment curves and unpotentiated supramaximal responses were recorded before and after IP or a low-pressure control intervention. Subsequently, the twitch interpolation technique was applied during maximal voluntary contractions to assess conventional parameters of neural output. Following IP, there was an increase in both maximum normalized force and voluntary activation (VA) for the plantar flexor group, with negligible peripheral alterations. Greater benefits were observed in participants with lower VA levels. Despite greater H-reflex gains, soleus volitional (V)-wave and sEMG amplitudes remained unchanged. In conclusion, IP improves muscle force via enhanced neural drive to the muscles. This effect appears associated, at least in part, to reduced presynaptic inhibition and/or increased motoneuron excitability. Furthermore, the magnitude of the benefit is inversely proportional to the skeletal muscle's functional reserve, making it particularly noticeable in under-recruited muscles. These findings have implications for the strategic application of the IP procedure across diverse populations.

Efficiency of pulsed electromagnetic field and neuromuscular electrical stimulation on painful shoulder following stroke / Eficiência do campo eletromagnético pulsado e da estimulação elétrica neuromuscular em ombro doloroso após acidente vascular cerebral

INTRODUCTION: Shoulder pain after stroke, a complication with a prevalence of up to 16­84% usually occurs after 2­3 months and leads to patients withdrawing from rehabilitation programs, staying in the hospital longer, having less limb function and having a great negative impact on their quality of life. The aim of the present study was to determine the effect of PEMF and NMES in reducing shoulder pain in patients with stroke. MATERIAL AND METHODS: A prospective, randomized controlled trial included 51 patients with shoulder pain following stroke. The patients were randomly assigned to three groups (17 people in each group): Pulsed Electromagnetic Field (PEMF), Neuromuscular Electrical Stimulation (NMES) and Control group. The outcome measures were Visual Analogue Scale (VAS), Modified Ashworth Scale (MAS) and Fugl Meyer Assessment­Upper Extremity (FMA-UE), Active and Passive Range of Motion (AROM/PROM) assessed at the baseline, six weeks into the intervention, and one week into the follow-up. RESULTS: VAS score for pain showed a mean change of 1.60, 1.60 and 4.94 in PEMF, NMES, and control respectively after 20 sessions. It showed pain was significantly improved in all the groups (p<0.001), but the effectiveness of the PEMF and NMES groups was superior to the control group. CONCLUSION: The current literature showed that PEMF & NMES are effective in improving post-stroke shoulder pain, spasticity, range of motion and motor function and a novel method for stroke patients undergoing rehabilitation.

INTRODUÇÃO: Dor no ombro após acidente vascular cerebral com prevalência de 16­84% geralmente ocorre após 2­3 meses e pode resultar na suspensão de programas de reabilitação, internações hospitalares mais longas e redução da função dos membros, prejudicando qualidade de vida dos pacientes com AVC. O objetivo do presente estudo foi determinar o efeito da PEMF e da EENM na redução da dor no ombro em pacientes com acidente vascular cerebral. MATERIAL E MÉTODOS: Um estudo prospectivo, randomizado e controlado incluiu 51 pacientes com dor no ombro pós-AVC. Os pacientes foram divididos aleatoriamente em três grupos (17 pessoas em cada grupo): grupo Campo Eletromagnético Pulsado (PEMF), grupo Estimulação Elétrica Neuromuscular (EENM) e grupo Controle. As medidas de resultados foram na Escala Visual Analógica (VAS), Escala de Ashworth Modificada (MAS) e Avaliação de Fugl Meyer ­ Extremidade Superior (FMA-UE), Amplitude de Movimento (AROM/PROM) foram avaliadas no início do estudo, após seis semanas de tratamento, e após um acompanhamento semanal. RESULTADOS: A pontuação VAS para dor mostrada uma alteração média de 1,60, 1,60 e 4,94 na PEMF, EENM e Controle, respectivamente, após 20 sessões. Mostrou melhora significativa entre os três grupos (p<0,001), mas a eficácia do grupo PEMF e EENM foi superior ao grupo Controle. CONCLUSÃO: O presente estudo mostrou que PEMF e EENM são eficazes na melhora da dor no ombro pós-AVC, espasticidade, amplitude de movimento e função motora e um novo método para pacientes com AVC em reabilitação. Nossas descobertas indicam que a eficácia da EENM é claramente superior à do PEMF na manutenção da analgesia a longo prazo.

Safety and feasibility of a functional electrical stimulation cycling-based muscular dysfunction diagnostic method in mechanically ventilated patients.

BACKGROUND: A nonvolitional diagnostic method based on FES-Cycling technology has recently been demonstrated for mechanically ventilated patients. This method presents good sensitivity and specificity for detecting muscle dysfunction and survival prognosis, even in unconscious patients. As the clinical relevance of this method has already been reported, we aimed to evaluate its safety and feasibility. METHODS: An observational prospective study was carried out with 20 critically ill, mechanically ventilated patients. The FES-cycling equipment was set in a specific diagnostic mode. For safety determination, hemodynamic parameters and peripheral oxygen saturation were measured before and immediately after the diagnostic protocol, as well as venous oxygen saturation and blood lactate. The creatine phosphokinase level (CPK) was measured before and 24, 48, and 72 h after the test. The time taken to carry out the entire diagnostic protocol and the number of patients with visible muscle contraction (capacity of perceptive muscular recruitment) were recorded to assess feasibility. RESULTS: Heart rate [91 ± 23 vs. 94 ± 23 bpm (p = 0.0837)], systolic [122 ± 19 vs. 124 ± 19 mm Hg (p = 0.4261)] and diastolic blood pressure [68 ± 13 vs. 70 ± 15 mm Hg (p = 0.3462)], and peripheral [98 (96-99) vs. 98 (95-99) % (p = 0.6353)] and venous oxygen saturation [71 ± 14 vs. 69 ± 14% (p = 0.1317)] did not change after the diagnostic protocol. Moreover, blood lactate [1.48 ± 0.65 vs. 1.53 ± 0.71 mmol/L (p = 0.2320)] did not change. CPK did not change up to 72 h after the test [99 (59-422) vs. 125 (66-674) (p = 0.2799) vs. 161 (66-352) (p > 0.999) vs. 100 (33-409) (p = 0.5901)]. The time taken to perform the diagnostic assessment was 11.3 ± 1.1 min. In addition, 75% of the patients presented very visible muscle contractions, and 25% of them presented barely visible muscle contractions. CONCLUSIONS: The FES cycling-based muscular dysfunction diagnostic method is safe and feasible. Hemodynamic parameters, peripheral oxygen saturation, venous oxygen saturation, and blood lactate did not change after the diagnostic protocol. The muscle damage marker (CPK) did not increase up to 72 h after the diagnostic protocol.

Effects of medium voltage electrical stimulation on initial pH decline and quality parameters during ageing and frozen storage of Nellore beef.

This study aimed to evaluate the influence of medium voltage electrical stimulation (ES) at three different intensities, 200 V (Treatment 200 V, T200), 300 V (Treatment 200 V, T300), and 400 V (Treatment 400 V, T400) on the initial pH decline in post mortem muscle and the quality parameters on M. longissimus thoracis - Nellore beef, both throughout the ageing process and during frozen storage. The colour, cooking loss, and shear force parameters for samples of aged beef were determined. Additional parameters, like thaw loss, pH, and lipid oxidation were also analyzed for the frozen storage. The shear force and cooking loss decreased and colour parameters increased in Nellore beef ES compared with CON on ageing time (14 days). At frozen storage, quality parameters like pH, a*, and b* were reduced over time, and no negative effect on lipid oxidation was found. Electrical stimulation at 200 V demonstrated effectiveness for decreasing shear force to Nellore beef (M. longissimus thoracis) during frozen storage. The application of medium voltage electrical stimulation can contribute to improved quality and tenderness in Nellore beef, both during ageing and frozen storage conditions.

Neuromuscular electrical stimulation changes glucose, but not its variability in type 2 diabetes: a randomized clinical trial.

Neuromuscular electrical stimulation (NMES) can be an alternative to conventional exercising. This randomized clinical trial evaluated the effect of NMES in type 2 diabetes patients. Twenty-eight individuals with type 2 diabetes were assigned to NMES (n=14) or NMES-placebo (n=14) applied to knee extensor muscles for 60 minutes. Glucose variability, microvascular function and endothelial function were evaluated through continuous glucose monitoring system, near infrared spectroscopy and flow-mediated dilatation, respectively. Glucose levels (mg/dl) decreased 2h (184 ± 11 vs 223 ±15), 3h (179 ± 12 vs 219 ±14) and 4h (177 ± 12 vs 212 ±12) after NMES, in comparison to NMES-placebo. No differences in glucose variability were found: coefficient of variation (%) at 0-6h (11.4±1.3 vs 11.4±1.2), 6-12h (9.8±1.0 vs 11.6±1.6), 12-18h (15.5±2.0 vs 11.4±2.1), 18-24h (12.8±2.3 vs 10.0±1.6); standard deviation (mg/dl) at 0-6h (21.6±2 vs 24.6±3.5), 6-12h (19.5±1.8 vs 20.3±2.8), 12-18h (29.9±3.5 vs 21.3±2.8),18-24h (22.8±4.1 vs 16.6±2.0) and mean amplitude of glycemic excursions (mg/dl) 54.9±25.0 vs 70.3±35.7. Endothelial and microvascular functions did not change. In conclusion, one acute NMES session was strong enough to trigger glucose reduction in individuals with type 2 DM, but it failed to induce any significant change in glucose variability, endothelial and microvascular functions.

Effect of Long-term Peripheral Nerve Stimulation on Neuro-Muscular Complex Morphologic Recovery in Experiment / Efecto de la Estimulación del Nervio Periférico a Largo Plazo sobre la Recuperación Morfológica del Complejo Neuromuscular en Experimento

SUMMARY: Peripheral nerve injury is an extremely important medical and socio-economic problem. It is far from a solution, despite on rapid development of technologies. To study the effect of long-term electrical stimulation of peripheral nerves, we used a domestically produced electrical stimulation system, which is approved for clinical use. The study was performed on 28 rabbits. Control of regeneration was carried out after 3 month with morphologic techniques. The use of long-term electrostimulation technology leads to an improvement in the results of the recovery of the nerve trunk after an injury, both directly at the site of damage, when stimulation begins in the early period, and indirectly, after the nerve fibers reach the effector muscle.

La lesión de los nervios periféricos es un problema médico y socioeconómico extremadamente importante. Sin embargo, y a pesar del rápido desarrollo de las tecnologías, aún no tiene solución. Para estudiar el efecto de la estimulación eléctrica a largo plazo de los nervios periféricos, utilizamos un sistema de estimulación eléctrica de producción nacional, que está aprobado para uso clínico. El estudio se realizó en 28 conejos. El control de la regeneración se realizó a los 3 meses con técnicas morfológicas. El uso de tecnología de electro estimulación a largo plazo conduce a una mejora en los resultados de la recuperación del tronco nervioso después de una lesión, tanto directamente en el lugar del daño, cuando la estimulación comienza en el período temprano, como indirectamente, después de que las fibras nerviosas alcanzan el músculo efector.

Alpha1-adrenergic blockers selectively antagonize the contractions induced by 6-nitrodopamine in the human vas deferens.

6-Nitrodopamine (6-ND) is released from human vas deferens and plays a modulatory role in the male ejaculation. Therapeutical use of α1-adrenoceptor antagonists is associated with ejaculatory abnormalities. To evaluate the effect of α1-adrenoceptor antagonists on the contractions induced by 6-ND, dopamine, noradrenaline, and adrenaline in the human epididymal vas deferens (HEVD). HEVD strips were suspended in glass chambers containing heated and oxygenated Krebs-Henseleit's solution. Cumulative concentration-response curves to catecholamines (10 nM-300 µM) were constructed in HEVD strips pre-incubated (30 min) with doxazosin (0.1-1 nM), tamsulosin (1-10 nM), prazosin (10-100 nM) and/or silodosin (0.1-10 nM). The effects of these α1-adrenoceptor antagonists were also evaluated in the electric-field stimulation (EFS, 2-32 Hz)-induced contractions. Doxazosin (0.1 nM) caused significant reductions in 6-ND-induced HEVD contractions without affecting the contractions induced by dopamine, noradrenaline, and adrenaline. Similar results were observed with tamsulosin (1 nM) and prazosin (10 nM). At these concentrations, these α1-adrenoceptor antagonists largely reduced the EFS-induced contractions. Silodosin (1 nM) caused concentration-dependent rightward shifts of the concentration-response curves to 6-ND but had no effect on the contractions induced by dopamine and adrenaline. Silodosin (0.1 nM) only inhibited the contractions induced by noradrenaline. Silodosin at 1 nM, but not at 0.1 nM, caused significant reductions in the EFS-induced contractions. The results reinforce the concept that 6-ND plays a major role in the human vas deferens contractility and indicate that the ejaculation disorders caused by doxazosin, tamsulosin, prazosin and silodosin cause in man, may be due to inhibition of the contractions induced by 6-ND rather than by the classical catecholamines dopamine, noradrenaline, and adrenaline.

Effectiveness of neuromuscular electrical stimulation training combined with exercise on patient-reported outcomes measures in people with knee osteoarthritis: A systematic review and meta-analysis.

OBJECTIVE: This study examined the effectiveness of neuromuscular electrical stimulation (NMES) added to the exercise or superimposed on voluntary contractions on patient-reported outcomes measures (PROMs) in people with knee osteoarthritis (OA). METHODS: This systematic review was described according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials (RCTs) were obtained from a systematic literature search in five electronic databases (PubMed, PEDro, LILACS, EMBASE, and SPORTDiscus) in April 2022. We described the effects of intervention according to each PROMs (scores for Pain; Self-reported functional ability; Symptoms (hear clicking, swelling, catching, restricted range of motion, and stiffness); Daily living function; Sports function; and Quality of life) and used a random-effect model to examine the impact of NMES plus exercise on pain compared with exercise in people with knee OA. RESULTS: Six RCTs (n = 367) were included. In the qualitative synthesis, the systematic literature analysis showed improvement in pain after NMES plus exercise compared with exercise alone in three studies. The other three studies revealed no difference between groups in pain, although similar improvement after treatments. In the meta-analysis, NMES at a specific joint angle combined with exercise was not superior to exercise alone in pain management (standardized mean difference = -0.33, 95% CI = -1.05 to 0.39, p = 0.37). There was no additional effect of NMES on exercise on self-reported functional ability, stiffness, and physical function compared with exercise alone. In only one study, symptoms, activities of daily living, sports function, and quality of life improved after whole-body electrostimulation combined with exercise. CONCLUSION: This review found insufficient evidence for the effectiveness of NMES combined with exercise in treating knee OA considering PROMs. While pain relief was observed in some studies, more high-quality clinical trials are needed to support the use of NMES added to the exercise in clinical practice. Electrical stimulation in a whole-body configuration combined with exercise shows promise as an alternative treatment option.

Functional electrical stimulation cycling-based muscular evaluation method in mechanically ventilated patients.

BACKGROUND: Intensive care acquired muscle weakness is a common feature in critically ill patients. Beyond the therapeutic uses, FES-cycling could represent a promising nonvolitional evaluation method for detecting acquired muscle weakness. OBJECTIVES: To assess whether FES-cycling is able to identify muscle dysfunctions, and to evaluate the survival rate in patients with detected muscle dysfunction. METHODS: A prospective observational study was carried out, with 29 critically ill patients and 20 healthy subjects. Maximum torque and power achieved were recorded, in addition to the stimulation cost, and patients were followed up for six months. RESULTS: Torque (2.64 [1.53 to 4.81] vs 6.03 [4.56 to 6.73] Nm) and power (3.31 [2.33 to 6.37] vs 6.35 [5.22 to 10.70] watts) were lower and stimulation cost (22 915 [5069 to 37 750] vs 3411 [2080 to 4024] µC/W) was higher in patients compared to healthy people (p < 0.05). Surviving patients showed a nonsignificant difference in power and torque in relation to nonsurvivors (p > 0.05), but they had a lower stimulation cost (4462 [3598 to 11 788] vs 23 538 [10 164 to 39 836] µC/W) (p < 0.05). In total, 34% of all patients survived during the six months of follow-up. Furthermore, 62% of patients with a stimulation cost below 15 371 µC/W and 7% of patients with a stimulation cost above 15 371 µC/W survived. CONCLUSIONS: FES-cycling has good sensitivity and specificity for detecting muscle disorders. Critical patients have low torque and power and a high stimulation cost. Stimulation cost is related to survival. A low stimulation cost was related to a 3 times greater chance of survival.

Clinical effect and prognostic factor of electric stimulation and biofeedback therapy on postpartum pelvic organ prolapse / Efeito clínico e fator prognóstico da estimulação elétrica e terapia de biofeedback no prolapso de órgãos pélvicos pós-parto / Efecto clínico y factor pronóstico de la estimulación eléctrica y la terapia de biorretroalimentación en el prolapso posparto de órganos pélvicos

ABSTRACT Objective: To explore the effects of electric stimulation and biofeedback therapy in patients with postpartum pelvic organ prolapse and to identify factors that can affect therapeutic efficacy outcomes. Method: This retrospective study analysed clinical data about patients with postpartum pelvic organ prolapse. A total of 328 women with pelvic organ prolapse at 6 weeks postpartum were recruited from one tertiary hospitals in Sichuan province in China, between March 2019 and March 2022. The prognostic factors of therapeutic efficacy were analysed using logistic regression and decision tree model. Results: Overall, 259 women showed clinical benefits from the treatment. The logistic regression model showed that parity, pelvic floor muscle training at home, and the pelvic organ prolapse quantitation stage before treatment were independent prognostic factors. The decision tree model showed that the pelvic organ prolapse quantitation stage before treatment was the main prognostic factor, followed by parity. There was no significant difference in the area under the receiver operating characteristic curve between the two models. Conclusion: Parity, pelvic floor muscle training at home, and the pelvic organ prolapse quantitation stage before treatment were important prognostic factors of electric stimulation and biofeedback therapy on postpartum pelvic organ prolapse.

RESUMO Objetivo: Explorar o efeito da estimulação elétrica e da terapia de biofeedback em pacientes com prolapso de órgãos pélvicos pós-parto e identificar fatores que podem afetar os resultados da eficácia terapêutica. Método: Este estudo é uma análise retrospectiva de dados clínicos de pacientes com prolapso de órgãos pélvicos pós-parto. Um total de 328 mulheres com prolapso de órgãos pélvicos nas seis semanas pós-parto foram recrutadas em um hospital terciário na província de Sichuan, na China, entre março de 2019 e março de 2022. Os fatores prognósticos de eficácia terapêutica foram analisados por meio de regressão logística e modelo de árvore de decisão. Resultados: No geral, 259 mulheres apresentaram benefícios clínicos com o tratamento. O modelo de regressão logística mostrou que a paridade, o treinamento muscular do assoalho pélvico em casa e o estágio de quantificação do prolapso de órgãos pélvicos antes do tratamento foram fatores prognósticos independentes. O modelo de árvore de decisão mostrou que o estágio de quantificação do prolapso de órgãos pélvicos antes do tratamento foi o principal fator prognóstico, seguido pela paridade. Não houve diferença significativa na área sob a curva ROC entre os dois modelos. Conclusão: A paridade, o treinamento muscular do assoalho pélvico em casa e o estágio de quantificação do prolapso de órgãos pélvicos antes do tratamento foram importantes fatores prognósticos da estimulação elétrica e da terapia de biofeedback no prolapso de órgãos pélvicos pós-parto.

RESUMEN Objetivo: Explorar el efecto de la estimulación eléctrica y la terapia de biorretroalimentación en pacientes con prolapso posparto de órganos pélvicos e identificar los factores que pueden afectar los resultados de la eficacia terapéutica. Método: Este estudio es un análisis retrospectivo de los datos clínicos de pacientes con prolapso posparto de órganos pélvicos. Entre marzo de 2019 y marzo de 2022, se reclutaron un total de 328 mujeres con prolapso de órganos pélvicos en las seis semanas posteriores al parto en un hospital terciario de la provincia de Sichuan, China. Los factores pronósticos de eficacia terapéutica se analizaron mediante regresión logística y el modelo de árbol de decisión. Resultados: En total, 259 mujeres mostraron beneficios clínicos relacionados con el tratamiento. El modelo de regresión logística mostró que la paridad, el entrenamiento en casa de la musculatura del suelo pélvico y la etapa de cuantificación del prolapso de órganos pélvicos antes del tratamiento fueron factores pronósticos independientes. El modelo de árbol de decisión mostró que la etapa de cuantificación del prolapso de órganos pélvicos previa al tratamiento fue el principal factor pronóstico, seguido de la paridad. No hubo diferencias significativas en el área bajo la curva ROC entre los dos modelos. Conclusión: La paridad, el entrenamiento en casa de la musculatura del suelo pélvico y la etapa de cuantificación del prolapso de órganos pélvicos previa al tratamiento fueron factores pronósticos importantes de la estimulación eléctrica y la terapia de biorretroalimentación en el prolapso posparto de órganos pélvicos.

Towards a more accurate quasi-static approximation of the electric potential for neurostimulation with kilohertz-frequency sources.

Objective.Our goal was to determine the conditions for which a more precise calculation of the electric potential than the quasi-static approximation may be needed in models of electrical neurostimulation, particularly for signals with kilohertz-frequency components.Approach.We conducted a comprehensive quantitative study of the differences in nerve fiber activation and conduction block when using the quasi-static and Helmholtz approximations for the electric potential in a model of electrical neurostimulation.Main results.We first show that the potentials generated by sources of unbalanced pulses exhibit different transients as compared to those of charge-balanced pulses, and this is disregarded by the quasi-static assumption. Secondly, relative errors for current-distance curves were below 3%, while for strength-duration curves these ranged between 1%-17%, but could be improved to less than 3% across the range of pulse duration by providing a corrected quasi-static conductivity. Third, we extended our analysis to trains of pulses and reported a 'congruence area' below 700 Hz, where the fidelity of fiber responses is maximal for supra-threshold stimulation. Further examination of waveforms and polarities revealed similar fidelities in the congruence area, but significant differences were observed beyond this area. However, the spike-train distance revealed differences in activation patterns when comparing the response generated by each model. Finally, in simulations of conduction-block, we found that block thresholds exhibited errors above 20% for repetition rates above 10 kHz. Yet, employing a corrected value of the conductivity improved the agreement between models, with errors no greater than 8%.Significance.Our results emphasize that the quasi-static approximation cannot be naively extended to electrical stimulation with high-frequency components, and notable differences can be observed in activation patterns. As well, we introduce a methodology to obtain more precise model responses using the quasi-static approach, retaining its simplicity, which can be a valuable resource in computational neuroengineering.