Preventive effects of sodium hyaluronate combined with pelvic floor neuromuscular electrical stimulation on the intrauterine adhesions in women after abortion

The aim of this study was to investigate the clinical efficacy of combining pelvic floor neuromuscular stimulation treatment (NMES) with sodium hyaluronate in preventing intrauterine adhesions (IUA) following abortion. A total of 140 women who underwent artificial abortion were enrolled. The control group received only an intrauterine injection of sodium hyaluronate post-surgery, while the observation group received both the injection and daily pelvic floor NMES treatments, beginning on the day after the abortion. Monthly follow-ups on menstrual conditions were conducted for six months post-surgery. Fasting venous blood samples from both groups were collected on the second day post-abortion and the day after treatment. Transvaginal color Doppler ultrasound was used on the second day post-abortion and the 15th day post the first menstrual cycle to measure endometrial thickness, and the pulsatility and resistance indices of the endometrial spiral arteries. Over the six-month follow-up, the combination therapy group exhibited a notably lower IUA incidence compared to the control group (2.8% vs. 15.7%). Furthermore, combined treatment significantly expedited post-abortion menstrual recovery, reduced vaginal bleeding volume and duration (P < 0.001). It also increased endometrial thickness and reduced the endometrial spiral artery's pulsatility and resistance indices (P < 0.05). In addition, lower serum tumor necrosis factor alpha (TNF-α) and higher interleukin-10 (IL-10) were found in the observation group compared to the control group (P < 0.05). The combination therapy offers significant advantages in preventing and reducing IUA after abortion, resulting in a substantial reduction in IUA occurrence.

Electrical Stimulation of Vocal Fold Adduction Triggered by Laryngeal Electromyography Using a Custom Implant

PURPOSE

Medialization procedures for unilateral vocal fold (VF) paralysis generally improve voice but do not fully replace dynamic VF adduction. Paralyzed VFs typically experience synkinetic reinnervation, which makes it feasible to elicit movement through electrical stimulation. We tested a novel laryngeal pacing implant capable of providing closed-loop (automatic) stimulation of a VF triggered by electromyography (EMG) potentials from the contralateral VF.

METHOD

A custom, battery-powered, microprocessor-based stimulator was tested in eight dogs with bipolar electrodes implanted for recording EMG from the left VF and stimulating adduction of the right VF. A cuff electrode on the left recurrent laryngeal nerve (RLN) stimulated unilateral VF adduction, modeling voluntary control in anesthetized animals. Closed-loop stimulation was tested in both acute and chronic experiments. Synkinetic reinnervation was created in two animals by right RLN transection and suture repair to model unilateral VF paralysis.

RESULTS

In all animals, left VF activation through RLN stimulation generated a robust EMG response that rapidly triggered stimulation of contralateral thyroarytenoid and lateral cricoarytenoid muscles, causing nearly simultaneous bilateral adduction. Optimal triggering of VF stimulation from elicited EMG was achieved using independent onset and offset thresholds. Real-time artifact blanking allowed closed-loop stimulation without self-perpetuating feedback, despite the proximity of recording and stimulation electrodes.

CONCLUSIONS

Using a custom implant system, we demonstrated real-time closed-loop stimulation of one VF triggered by the activation of the contralateral VF. This approach could potentially restore dynamic glottic closure for reflexive behaviors or phonation in cases of unilateral VF paralysis with synkinetic reinnervation.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24492133.

Modulation of the spinal N13 SEP component by high- and low-frequency electrical stimulation. Experimental pain models matter

OBJECTIVE

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of cervical dorsal horn neurons. Neurophysiological studies in healthy participants showed that capsaicin-induced central sensitization causes an increase of the N13 SEP amplitude. Consequently, in human research, this spinal component may serve as a valuable readout of central sensitization. In this study, we wanted to verify if the sensitivity of the N13 SEP for detecting central sensitization is consistent across different experimental pain models inducing central sensitization and secondary hyperalgesia, namely high and low-frequency electrical stimulation (HFS and LFS).

METHODS

In 18 healthy participants, we recorded SEP after bilateral ulnar nerve stimulation before and after secondary hyperalgesia was induced through HFS and LFS applied on the ulnar nerve territory of the hand of one side. The area of secondary hyperalgesia was mapped with a calibrated 128-mN pinprick probe, and the mechanical pain sensitivity with three calibrated 16-64-256-mN pinprick probes.

RESULTS

Although both HFS and LFS successfully induced secondary hyperalgesia only LFS increased the amplitude of the N13 SEP.

CONCLUSIONS

These findings suggest that the sensitivity of the N13 SEP for detecting dorsal horn excitability changes may critically depend on the different experimental pain models.

SIGNIFICANCE

Our results indicate that LFS and HFS could trigger central sensitization at the dorsal horn level through distinct mechanisms, however this still needs confirmation by replication studies.

Electrical stimulation mitigates muscle degradation shift in gene expressions during 12-h mechanical ventilation

Ventilator-induced diaphragm dysfunction (VIDD), a dysfunction of the diaphragm muscle caused by prolonged mechanical ventilation (MV), is an important factor that hinders successful weaning from ventilation. We evaluated the effects of electrical stimulation of the diaphragm muscle (pulsed current with off-time intervals) on genetic changes during 12 h of MV (E-V12). Rats were divided into four groups: control, 12-h MV, sham operation, and E-V12 groups. Transcriptome analysis using an RNA microarray revealed that 12-h MV caused upregulation of genes promoting muscle atrophy and downregulation of genes facilitating muscle synthesis, suggesting that 12-h MV is a reasonable method for establishing a VIDD rat model. Of the genes upregulated by 12-h MV, 18 genes were not affected by the sham operation but were downregulated by E-V12. These included genes related to catabolic processes, inflammatory cytokines, and skeletal muscle homeostasis. Of the genes downregulated by 12-h MV, 6 genes were not affected by the sham operation but were upregulated by E-V12. These included genes related to oxygen transport and mitochondrial respiration. These results suggested that 12-h MV shifted gene expression in the diaphragm muscle toward muscle degradation and that electrical stimulation counteracted this shift by suppressing catabolic processes and increasing mitochondrial respiration.

Gastric electrical stimulation is safe during pregnancy and delivery: Results from a French cohort

BACKGROUND

Gastric electrical stimulation (GES) is an effective therapy in medically refractory chronic nausea and vomiting. GES is assumed to be a contraindication for pregnancy. We examined the safety of GES during pregnancy and its clinical impact on vomiting symptoms.

METHODS

A retrospective study was performed in two tertiary centers including all female patients of childbearing age implanted with GES. Patients without pregnancy while on GES were asked about their desire and concerns about pregnancy. Patients who were pregnant while on GES therapy were interviewed about the course of the pregnancy and labor, as well as the health of the children.

KEY RESULTS

Among 91 patients implanted at childbearing age, 54 patients without pregnancy answered the questionnaire. Nine patients (16.7%) reported a desire for pregnancy and five patients (7.4%) reported worries about the safety of GES during pregnancy. Sixteen pregnancies were reported in 10 patients. All pregnancies ended in a live birth with premature birth in 12 pregnancies (75.0%). No health concern was currently noted in these children. No severe GES-related complications occurred during pregnancy with only pain at the implantation site reported during 3 pregnancies (18.8%). The severity and frequency of nausea and vomiting significantly increased during the first trimester (p = 0.04 and p = 0.005, respectively) and decreased after the delivery, becoming lower than before the pregnancy (p = 0.044 and p = 0.011, respectively).

CONCLUSION & INFERENCES

Patients are concerned regarding pregnancy while being treated with GES. No serious maternal or fetal complications related to GES were noted in our cohort.

Effects on hemodynamic enhancement and discomfort of a new textile electrode integrated in a sock during calf neuromuscular electrical stimulation

PURPOSE

To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES).

METHODS

Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0-10). Significance was set to p < 0.05.

RESULTS

TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different.

CONCLUSION

TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE.

TRIAL REGISTRATION

Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview

Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.

Neuromuscular Electrical Stimulation in Conjunction with Conventional Swallowing Therapy in the Treatment of Dysphagia Caused by Multiple Sclerosis: A Single-Case Experimental Design

INTRODUCTION

Dysphagia as a consequence of multiple sclerosis (MS) puts individuals at higher risk of dehydration, malnutrition, and aspiration pneumonia. This study intended to investigate the effects of a combined program of neuromuscular electrical stimulation (NMES) and conventional swallowing therapy to improve swallow safety and efficiency, oral intake, and physical, emotional, and functional impacts of dysphagia in people with dysphagia and MS.

METHODS

In this single-case experimental study with ABA design, two participants with dysphagia caused by MS underwent 12 sessions therapy during 6 weeks following a baseline of 4 evaluation sessions. They were evaluated 4 more times in the follow-up phase after therapy sessions. Scores of Mann Assessment of Swallowing Ability (MASA), DYsphagia in MUltiple Sclerosis (DYMUS), and timed test of swallowing capacity were obtained at baseline, during treatment, and in the follow-up phases. The Dysphagia Outcome and Severity Scale (DOSS) based on videofluoroscopic swallow studies, Persian-Dysphagia Handicap Index (Persian-DHI), and Functional Oral Intake Scale (FOIS) were also completed before and after treatment. Visual analysis and percentage of nonoverlapping data were calculated.

RESULTS

MASA, DYMUS, FOIS, and DHI scores indicated significant improvement in both participants. Although the scores of the timed test of swallowing capacity in participant 1 (B.N.) and DOSS in participant 2 (M.A.) showed no changes, considerable improvements including reducing the amount of residue and the number of swallows required to clear bolus were seen in the posttreatment videofluoroscopic records of both participants.

CONCLUSION

NMES in conjunction with conventional dysphagia therapy based on motor learning principles could improve the swallowing function and decrease disabling effects of dysphagia on different aspects of life in participants with dysphagia caused by MS.

The Effect of Observing High or Low Pain on the Development of Central Sensitization

It is unknown whether watching other people in high pain increases mechanical hypersensitivity induced by pain. We applied high-frequency electrical stimulation (HFS) on the skin of healthy volunteers to induce pinprick mechanical hypersensitivity. Before HFS participants were randomly allocated to 2 groups: in the low pain group, which was the control condition, they watched a model expressing and reporting lower pain scores, in the high pain group the model expressed and reported higher scores. The 2 videos were selected on the basis of a pilot/observational study that had been conducted before. We tested the differences in perceived intensity of the HFS procedure, in the development of hypersensitivity and the role of fear and empathy. The high pain group reported on average higher pain ratings during HFS. The perceived intensity of hypersensitivity, but not the unpleasantness or the length of the area was higher in the high pain group. Our results suggest that watching a person expressing more pain during HFS increases one's own pain ratings during HFS and may weakly facilitate the development of secondary mechanical hypersensitivity, although this latter result needs replication. PERSPECTIVE: Observing a person in high pain can influence the perceived pain intensity of a procedure leading to secondary mechanical hypersensitivity, and has a weak effect on hypersensitivity itself. The role of fear remains to be elucidated.

Acute effect of electrical stimulation on muscle protein synthesis and break-down in the soleus muscle of hindlimb unloaded rats

Electrical stimulation (ES) is effective for disuse-induced muscle atrophy. However, the acute effect of ES on muscle protein synthesis (MPS) and muscle protein breakdown (MPB) remains unclear. We investigated the effect of a single-session ES treatment on mTORC1 signaling, MPS, and MPB in the soleus muscle of 2-week hindlimb unloaded rats. Sprague Dawley rats (n = 12 male) were randomly divided into control (CON) and hindlimb unloaded (HU) groups. After 2 weeks, the right soleus muscle was percutaneously stimulated and underwent supramaximal isometric contractions. The left soleus muscle served as an internal control. We collected soleus muscle samples 6 h after ES. Two weeks of HU decreased p70S6K and S6rp activation, downstream factors for mTORC1 signaling, and SUnSET method-assessed MPS, but increased the LC3-II/I ratio, an indicator of autophagy. ES on disused muscle successfully activated mTORC1 signaling but did not affect MPS. Contrary, ES decreased ubiquitinated proteins expression and LC3B-II/I ratio. HU might affect mTORC1 activation and MPS differently in response to acute ES possibly due to excessive ROS production caused by ES. Our findings suggest that ES applied to disused skeletal muscles may suppress MPB, but its effect on MPS appears to be attenuated.

Mechanism behind the neuronal ephaptic coupling during synchronizing by specific brain-triggered wave as neuronal motor toolkit

Probable mechanism behind the neuronal ephaptic coupling is investigated based on the introduction of "Brain"-triggered potential excitation signal smartly with a specific very low frequency (VLF) waves as a neuronal motor toolkit. Detection of this electric motor toolkit is attributed to in-vitro precise analyses of a neural network of snail, along to the disconnected snail's neuronal network as a control. This is achieved via rapid (real-time) electrical signals acquisition by blind patch-clamp method during micro-electrode implanting in the neurons at the gigaseal conditions by the surgery operations. This process is based on its waveform (potential excitation signal) detection by mathematical curve fitting process. The characterized waveform of this electrical signal is "Saw Tooth" that is smartly stimulated, alternatively, by the brain during triggering the action potential's (AP's) hyperpolarization zone at a certain time interval at the several µs levels. Triggering the neuron cells results in (1) observing a positive shift (10.0%, depending on the intensity of the triggering wave), and (2) major promotion in the electrical current from sub nano (n) to micro (µ) amper (nA, µA) levels. Direct tracing the time domain (i.e., electrical signal vs. time) and estimation of the frequency domain (diagram of electrical response vs. the applied electrical frequencies) by the "Discrete Fast Fourier Transform" algorithm approve the presence of bilateral and reversible electrical currents between axon and dendrite. This mechanism therefore opens a novel view about the neuronal motor toolkit mechanism, versus the general knowledge about the unilateral electrical current flow from axon to dendrite operations in as neural network. The reliability of this mechanism is evaluated via (1) sequential modulation and demodulation of the snail's neuron network by a simulation electrical functions and sequentially evaluation of the neuronal current sensitivity between pA and nA (during the promotion of the signal-to-noise ratio, via averaging of 30 ± 1 (n = 15) and recycling the electrical cycles before any neuronal response); and (2) operation of the process on the differentiated stem cells. The interstice behavior is attributed to the effective role of Ca2+ channels (besides Na+ and K+ ionic pumping), during hyper/hypo calcium processes, evidenced by inductively coupled plasma as the selected analytical method. This phenomenon is also modeled during proposing quadrupole well potential levels in the neuron systems. This mechanism therefore points to the microprocessor behavior of neuron networks. Stimulation of the neuronal system based on this mechanism, not only controls the sensitivity of neuron electrical stimulation, but also would open a light window for more efficient operating the neuronal connectivity during providing interruptions by phenomena such as neurolysis as well as an efficient treatment of neuron-based disorders.

Generalization of Conditioned Contextual Anxiety and the Modulatory Effects of Anxiety Sensitivity

Anxiety patients overgeneralize fear responses, possibly because they cannot distinguish between cues never been associated with a threat (i.e., safe) and threat-associated cues. However, as contexts and not cues are discussed as the relevant triggers for prolonged anxiety responses characterizing many anxiety disorders, we speculated that it is rather overgeneralization of contextual anxiety, which constitutes a risk factor for anxiety disorders. To this end, we investigated generalization of conditioned contextual anxiety and explored modulatory effects of anxiety sensitivity, a risk factor for anxiety disorders. Fifty-five participants underwent context conditioning in a virtual reality paradigm. On Day 1 (acquisition), participants received unpredictable mildly painful electric stimuli (unconditioned stimulus, US) in one virtual office (anxiety context, CTX+), but never in a second office (safety context, CTX-). Successful acquisition of conditioned anxiety was indicated by aversive ratings and defensive physiological responses (i.e., SCR) to CTX+ vs CTX-. On Day 2 (generalization), participants re-visited both the anxiety and the safety contexts plus three generalization contexts (G-CTX), which were gradually dissimilar to CTX+ (from 75 to 25%). Generalization of conditioned anxiety was evident for ratings, but less clear for physiological responses. The observed dissociation between generalization of verbal and physiological responses suggests that these responses depend on two distinct context representations, likely elemental and contextual representations. Importantly, anxiety sensitivity was positively correlated with the generalization of reported contextual anxiety. Thus, this study demonstrates generalization gradients for conditioned contextual anxiety and that anxiety sensitivity facilitates such generalization processes suggesting the importance of generalization of contextual anxiety for the development of anxiety disorders.

Changes in autonomic nervous function and influencing factors in a rat insular cortex electrical kindling model

In mammals, the insular cortex plays an important role in autonomic regulation. In patients with insular epilepsy, seizures are always accompanied by autonomic changes. Accordingly, we aimed to establish an electrical kindling model in autonomic-mediating areas of the insular cortex, and to conduct a long-term observation of epileptic genesis in these animals until sudden unexpected death. To establish this model in adult rats, we implanted stimulation electrodes in the granular cell layer of the insular cortex, which controls the heart rate (HR) and respiratory rate (RR). Subsequently, seizure was induced successfully in 92.3 % of the rats, and typical autonomic changes were observed during these seizures. Interestingly, the model was established more easily in older rats, and the rats in which electrical stimulation led to a greater reduction in the HR. Moreover, death occurred in 25 % of the kindled rats. In conclusion, our kindling model demonstrates the ability of insular cortex stimulation to generate epilepsy. Our model thus offers a practical tool for studies of the role of the insular cortex in sudden unexpected death in epilepsy.

Memory for non-painful auditory items is influenced by whether they are experienced in a context involving painful electrical stimulation

In this study, we sought to examine the effect of experimentally induced somatic pain on memory. Subjects heard a series of words and made categorization decisions in two different conditions. One condition included painful shocks administered just after presentation of some of the words; the other condition involved no shocks. For the condition that included painful stimulations, every other word was followed by a shock, and subjects were informed to expect this pattern. Word lists were repeated three times within each condition in randomized order, with different category judgments but consistent pain-word pairings. After a brief delay, recognition memory was assessed. Non-pain words from the pain condition were less strongly encoded than non-pain words from the completely pain-free condition. Recognition of pain-paired words was not significantly different than either subgroup of non-pain words. An important accompanying finding is that response times to repeated experimental items were slower for non-pain words from the pain condition, compared to non-pain words from the completely pain-free condition. This demonstrates that the effect of pain on memory may generalize to non-pain items experienced in the same experimental context.

Quantitative Assessment of Changes in Muscle Contractility Due to Fatigue During NMES: An Ultrasound Imaging Approach

OBJECTIVE

This paper investigates an ultrasound imaging-based non-invasive methodology to quantitatively assess changes in muscle contractility due to the fatigue induced by neuromuscular electrical stimulation (NMES).

METHODS

Knee extension experiments on human participants were conducted to record synchronized isometric knee force data and ultrasound images of the electrically stimulated quadriceps muscle. The data were first collected in a pre-fatigue stage and then in a post-fatigue stage. Ultrasound images were processed using a contraction rate adaptive speckle tracking algorithm. A two-dimensional strain measure field was constructed based on the muscle displacement tracking results to quantify muscle contractility.

RESULTS

Analysis of the strain images showed that, between the pre-fatigue and post-fatigue stages, there was a reduction in the strain peaks, a change in the strain peak distribution, and a decrease in an area occupied by the large positive strain.

CONCLUSION

The results indicate changes in muscle contractility due to the NMES-induced muscle fatigue.

SIGNIFICANCE

Ultrasound imaging with the proposed methodology is a promising tool for a direct NMES-induced fatigue assessment and facilitates new strategies to alleviate the effects of the NMES-induced fatigue.

Modeling of Brain Tissue Heating Caused by Direct Cortical Stimulation for Assessing the Risk of Thermal Damage

This paper aims to employ the numerical simulations to assess the risk of cellular damage during the application of a novel paradigm of electrical stimulation mapping (ESM) used in neurosurgery. The core principle of the paradigm is the use of short, high-intensity and high-frequency stimulation pulses. We developed a complex numerical model and performed coupled electro-thermal transient simulations. The model was optimized by incorporating ESM electrodes' resistance obtained during multiple intraoperative measurements and validated by comparing them with the results of temperature distribution measurement acquired by thermal imaging. The risk of heat-induced cellular damage was assessed by applying the Arrhenius equation integral on the computed time-dependent spatial distribution of temperature in the brain tissue. Our results suggest that the impact of the temperature increase during our novel ESM paradigm is thermally non-destructive. The presented simulation results match the previously published thermographic measurement and histopathological examination of the stimulated brain tissue and confirm the safety of the novel ESM.

Nocebo Effects and Scratching Behaviour on Itch

Nocebo effects, i.e. reduced treatment effects due to patients' negative expectations, play a role in itch. Recent studies have shown that nocebo effects can be induced experimentally on itch and also be minimized and even turned into the opposite direction, i.e. placebo effects. It is not known whether these effects generalize to itch-associated scratching behaviour. The aim of this study was to determine whether induction and reversal of nocebo effects on itch evoked by electrical and histamine stimuli generalized to scratching. Ninety-seven healthy participants were included in the study. The manipulation was successful, as during the nocebo learning phase, increased scratching responses were found for higher intensity compared with lower intensity itch stimuli. During the testing phase of induction or reversal of the nocebo effects, however, no significant nocebo effects or reversed nocebo effects, were found in scratching. Thus, no straightforward generalization of nocebo effects from itch to scratching was found in this laboratory setting. Further investigation into possible generalization is needed in different settings and in patients with chronic itch.

Effects of the relative timing of opposite-polarity pulses on loudness for cochlear implant listeners

The symmetric biphasic pulses used in contemporary cochlear implants (CIs) consist of both cathodic and anodic currents, which may stimulate different sites on spiral ganglion neurons and, potentially, interact with each other. The effect on the order of anodic and cathodic stimulation on loudness at short inter-pulse intervals (IPIs; 0-800 μs) is investigated. Pairs of opposite-polarity pseudomonophasic (PS) pulses were used and the amplitude of each pulse was manipulated independently. In experiment 1 the two PS pulses differed in their current level in order to elicit the same loudness when presented separately. Six users of the Advanced Bionics CI (Valencia, CA) loudness-ranked trains of the pulse pairs using a midpoint-comparison procedure. Stimuli with anodic-leading polarity were louder than those with cathodic-leading polarity for IPIs shorter than 400 μs. This effect was small-about 0.3 dB-but consistent across listeners. When the same procedure was repeated with both PS pulses having the same current level (experiment 2), anodic-leading stimuli were still louder than cathodic-leading stimuli at very short intervals. However, when using symmetric biphasic pulses (experiment 3) the effect disappeared at short intervals and reversed at long intervals. Possible peripheral sources of such polarity interactions are discussed.

Effectiveness of percutaneous neuromuscular electrical stimulation for neck pain relief in patients with cervical spondylosis

BACKGROUND

This study aimed to evaluate the effectiveness and safety of percutaneous neuromuscular electrical stimulation (PNMES) for treating neck pain in patients with cervical spondylosis (CS).

METHODS

One hundred and twenty four patients with neck pain of CS were included, and then they were randomly divided into a PNMES group and a control group in a ratio of 1:1. All patients received PNMES or sham PNMES 30 minutes daily, 3 times weekly for 12 weeks. The primary outcome was assessed by the visual analog scale (VAS). The secondary outcomes were evaluated by the cervical range of motion (ROM), neck disability index (NDI) score, as well as the adverse events (AEs). All outcome measurements were measured at the end of 12-week treatment, and 4-week follow-up after treatment.

RESULTS

At the end of the 12-week treatment, and 4-week follow-up, the patients receiving PNMES exhibited more decrease in the mean VAS (P < .01), and NDI (P < .01) respectively, compared with the patients receiving sham PNMES. Additionally, the increase in the mean ROM was also significantly higher in the PNMES group than that in the sham PNMES group at the end of the 12-week treatment, and 4-week follow-up, respectively (P < .01). No AEs were found in either group.

CONCLUSIONS

The results of this study demonstrated that PNMES is more effective than Sham PNMES for neck pain relief in patients with CS.

Endocannabinoid CB1 receptors are involved in antiepileptogenic effect of low frequency electrical stimulation during perforant path kindling in rats

INTRODUCTION

Administration of low-frequency electrical stimulation (LFS) at the kindling site has an antiepileptogenic effect. In the present study, we investigated the role of cannabinoid receptors type 1 (CB1) in mediating the inhibitory effects of LFS on the development of perforant path kindled seizures.

METHODS

For seizure generation, rats were kindled by electrical stimulation of perforant path in semi-rapid kindling manner (12 stimulations per day at 10 min intervals at afterdischarge threshold intensity).To determine the effect of LFS (0.1 ms pulse duration at 1 Hz, 800 pulses) on seizure generation, LFS was applied to the perforant path 5 min after the last kindling stimulation daily. AM281, a CB1 receptor antagonist, was microinjected into the lateral ventricle immediately after the last kindling stimulation (before LFS application) at the doses of 0.5 and 2 μg/μl during kindling procedure. The expression of cannabinoid receptors in the dentate gyrus was also investigated using immunohistochemistry.

RESULTS

Application of LFS had inhibitory effect on development of kindled seizures (kindling rate). Microinjection of AM281 (0.5 μg/μl) immediately after the last kindling stimulation (before LFS application) reduced the inhibitory effect of LFS on the kindling rate and suppressed the effects of LFS on potentiation (increasing the magnitude) of both population spike amplitude and population excitatory postsynaptic potential slope during kindling acquisition. AM281 pretreatment also prevented the effects of LFS on kindling-induced increase in early and late paired pulse depression. The higher dose of AM281 (2 μg/μl) failed to exert the effects observed with its lower dose (0.5 μg/μl). In addition, there was a decreased CB1 receptors immunostaining in kindled animals compared to control. However, application of LFS following kindling stimulations led to overexpression of CB1 receptors in the dentate gyrus.

CONCLUSION

Obtained results showed that activation of overexpressed cannabinoid CB1 receptors by endogenous cannabinoids may have a role in mediating the inhibitory effect of LFS on perforant path kindled seizures.

Safety of neuromuscular electrical stimulation among critically ill patients: systematic review

OBJECTIVE

To review the evidence on the safety of neuromuscular electrical stimulation when used in the intensive care unit.

METHODS

A systematic review was conducted; a literature search was performed of the MEDLINE (via PubMed), PEDro, Cochrane CENTRAL and EMBASE databases, and a further manual search was performed among the references cited in randomized studies. Randomized clinical trials that compared neuromuscular electrical stimulation to a control or placebo group in the intensive care unit and reporting on the technique safety in the outcomes were included. Hemodynamic variables and information on adverse effects were considered safety parameters. Articles were independently analyzed by two reviewers, and the data analysis was descriptive.

RESULTS

The initial search located 1,533 articles, from which only four randomized clinical trials were included. Two studies assessed safety based on hemodynamic variables, and only one study reported an increase in heart rate, respiratory rate and blood lactate, without clinical relevance. The other two studies assessed safety based on reported adverse effects. In one, 15% of patients described a prickling sensation, without any clinically relevant abnormalities. In the other, one patient suffered a superficial burn due to improper parameter configuration.

CONCLUSION

Neuromuscular electrical stimulation is safe for critically ill patients; however, it should be applied by duly trained professionals and with proper evidence-based parameters.

Minimizing nocebo effects by conditioning with verbal suggestion: A randomized clinical trial in healthy humans

Nocebo effects, i.e., adverse treatment effects which are induced by patients' expectations, are known to contribute to the experience of physical symptoms such as pain and itch. A better understanding of how to minimize nocebo responses might eventually contribute to enhanced treatment effects. However, little is known about how to reduce nocebo effects. In the current randomized controlled study, we tested whether nocebo effects can be minimized by positive expectation induction with respect to electrical and histaminic itch stimuli. First, negative expectations about electrical itch stimuli were induced by verbal suggestion and conditioning (part 1: induction of nocebo effect). Second, participants were randomized to either the experimental group or one of the control groups (part 2: reversing nocebo effect). In the experimental group, positive expectations were induced by conditioning with verbal suggestion. In the control groups either the negative expectation induction was continued or an extinction procedure was applied. Afterwards, a histamine application test was conducted. Positive expectation induction resulted in a significantly smaller nocebo effect in comparison with both control groups. Mean change itch NRS scores showed that the nocebo effect was even reversed, indicating a placebo effect. Comparable effects were also found for histamine application. This study is the first to demonstrate that nocebo effects can be minimized and even reversed by conditioning with verbal suggestion. The results of the current study indicate that learning via counterconditioning and verbal suggestion represents a promising strategy for diminishing nocebo responses.

Pattern Analyses Reveal Separate Experience-Based Fear Memories in the Human Right Amygdala

Learning fear via the experience of contingencies between a conditioned stimulus (CS) and an aversive unconditioned stimulus (US) is often assumed to be fundamentally different from learning fear via instructions. An open question is whether fear-related brain areas respond differently to experienced CS-US contingencies than to merely instructed CS-US contingencies. Here, we contrasted two experimental conditions where subjects were instructed to expect the same CS-US contingencies while only one condition was characterized by prior experience with the CS-US contingency. Using multivoxel pattern analysis of fMRI data, we found CS-related neural activation patterns in the right amygdala (but not in other fear-related regions) that dissociated between whether a CS-US contingency had been instructed and experienced versus merely instructed. A second experiment further corroborated this finding by showing a category-independent neural response to instructed and experienced, but not merely instructed, CS presentations in the human right amygdala. Together, these findings are in line with previous studies showing that verbal fear instructions have a strong impact on both brain and behavior. However, even in the face of fear instructions, the human right amygdala still shows a separable neural pattern response to experience-based fear contingencies.SIGNIFICANCE STATEMENT In our study, we addressed a fundamental problem of the science of human fear learning and memory, namely whether fear learning via experience in humans relies on a neural pathway that can be separated from fear learning via verbal information. Using two new procedures and recent advances in the analysis of brain imaging data, we localized purely experience-based fear processing and memory in the right amygdala, thereby making a direct link between human and animal research.

The role of treatment timing and mode of stimulation in the treatment of primary dysmenorrhea with acupuncture: An exploratory randomised controlled trial

OBJECTIVES

We examined the effect of changing treatment timing and the use of manual, electro acupuncture on the symptoms of primary dysmenorrhea.

METHODS

A randomised controlled trial was performed with four arms, low frequency manual acupuncture (LF-MA), high frequency manual acupuncture (HF-MA), low frequency electro acupuncture (LF-EA) and high frequency electro acupuncture (HF-EA). A manualised trial protocol was used to allow differentiation and individualized treatment over three months. A total of 74 women were randomly assigned to one of the four groups (LF-MA n = 19, HF-MA n = 18, LF-EA n = 18, HF-EA n = 19). Twelve treatments were performed over three menstrual cycles, either once per week (LF groups) or three times in the week prior to menses (HF groups). All groups received a treatment in the first 48 hours of menses. The primary outcome was the reduction in peak menstrual pain at 12 months from trial entry.

RESULTS

During the treatment period and nine month follow-up all groups showed statistically significant (p < .001) reductions in peak and average menstrual pain compared to baseline but there were no differences between groups (p > 0.05). Health related quality of life increased significantly in six domains in groups having high frequency of treatment compared to two domains in low frequency groups. Manual acupuncture groups required less analgesic medication than electro-acupuncture groups (p = 0.02). HF-MA was most effective in reducing secondary menstrual symptoms compared to both-EA groups (p<0.05).

CONCLUSION

Acupuncture treatment reduced menstrual pain intensity and duration after three months of treatment and this was sustained for up to one year after trial entry. The effect of changing mode of stimulation or frequency of treatment on menstrual pain was not significant. This may be due to a lack of power. The role of acupuncture stimulation on menstrual pain needs to be investigated in appropriately powered randomised controlled trials.

Genetic resistance to kindling associated with alterations in circuit function

How a seizure spreads from a focal onset zone to other regions of the brain is not well understood, and animal studies suggest that there is a genetic influence. To understand how genetic factors may influence seizure spread, we examined whether the kindling resistance of WAG/Rij rats, which are slow to develop kindled motor seizures, is independent of the site of seizure induction and thus a global phenomenon, or whether it is circuit specific. We compared the kindling rates (number of stimulations to induce kindled motor seizures) of WAG/Rij rats to the rates of kindling in Sprague Dawley rats. Both groups underwent a standard hippocampal kindling protocol and a separate group was kindled from the medial dorsal nucleus of the thalamus, a site that has been previously demonstrated to result in the very rapid development of motor seizures. To examine whether there were differences in the interaction in a circuit involved with the motor seizures, evoked responses were obtained from the prefrontal cortex following stimulation of the subiculum or medial dorsal thalamic nucleus. The WAG/Rij rats once again demonstrated resistance to kindling in the hippocampus, but both strains kindled rapidly from the medial dorsal nucleus. In the WAG/Rij rats there was also a reduction in the duration of the afterdischarge in the frontal cortex during hippocampal stimulation, but there was no reduction during thalamic kindling. The prefrontal cortex evoked responses were reduced following stimulation of the subiculum in the WAG/Rij rats, but the evoked responses to thalamic stimulation were the same in both strains. These findings suggest that there are genetic influences in the strength of the input from the subiculum to the prefrontal cortex in WAG/Rij rats that could explain the resistance to limbic kindling because of reduced excitatory drive onto a key target region.

Phase-locked and non-phase-locked EEG responses to pinprick stimulation before and after experimentally-induced secondary hyperalgesia

OBJECTIVE

Pinprick-evoked brain potentials (PEPs) have been proposed as a technique to investigate secondary hyperalgesia and central sensitization in humans. However, the signal-to-noise (SNR) of PEPs is low. Here, using time-frequency analysis, we characterize the phase-locked and non-phase-locked EEG responses to pinprick stimulation, before and after secondary hyperalgesia.

METHODS

Secondary hyperalgesia was induced using high-frequency electrical stimulation (HFS) of the left/right forearm skin in 16 volunteers. EEG responses to 64 and 96mN pinprick stimuli were elicited from both arms, before and 20min after HFS.

RESULTS

Pinprick stimulation applied to normal skin elicited a phase-locked low-frequency (<5Hz) response followed by a reduction of alpha-band oscillations (7-10Hz). The low-frequency response was significantly increased when pinprick stimuli were delivered to the area of secondary hyperalgesia. There was no change in the reduction of alpha-band oscillations. Whereas the low-frequency response was enhanced for both 64 and 96mN intensities, PEPs analyzed in the time domain were only significantly enhanced for the 64mN intensity.

CONCLUSIONS

Time-frequency analysis may be more sensitive than conventional time-domain analysis in revealing EEG changes associated to secondary hyperalgesia.

SIGNIFICANCE

Time-frequency analysis of PEPs can be used to investigate central sensitization in humans.

Electric injury-induced Purkinje cell apoptosis in rat cerebellum: Histological and immunohistochemical study

INTRODUCTION

Electrical injury is a prominent problem in low income countries with increased morbidity and mortality rate. Nervous system is one of the most susceptible systems to electrical current because of its low resistance. There were different studies demonstrated electrocution effect on the nervous system, however little was made on the cerebellum.

AIM

This study was conducted to produce an experimental suggestion concerning injury of the nervous system through evaluating Purkinje cell apoptosis and number in rat cerebellum by fatal and non-fatal electric current using histological and immunohistochemical study. Also to support the diagnosis of electrocution as a probable cause of death and delayed neurological damage as well as disability.

MATERIALS & METHODS

Fifty male Wistar rats were divided into five groups (10 rats each); control group: normal rats that were sacrificed without exposure to electric current, groups 1-3 (non-fatal electrocution groups): rats were exposed to alternating electric current (220v, 50Hz) for one minute then were sacrificed immediately, after 2h, and after 4h respectively, and group 4 (fatal electrocution group): rats were sacrificed after being electrified up to death (153±27s). Sections from cerebellum were processed for histological and caspase-3 immunohistochemical study.

RESULTS

Purkinje cells showed marked histopathological changes in the form of shrunken dark stained cells with significant reduction of their number in H &E stained sections when compared to control, widespread argyrophilia, and degenerated organelles along with shrunken irregular nuclei. For caspase-3 staining, there was significantly increased number of caspase-3 positive cells in groups 1-3 (non-fatal electrocution groups) and markedly increased in group 4 (fatal electrocution group) in comparison to control group. These changes were gradually increased with the increased duration after exposure to the electric current.

CONCLUSION

Apoptosis and loss of Purkinje cells were involved in the pathogenesis of immediate and long term effect of electrical injury on Purkinje cells, which will be an aid to the forensic pathologist to determine the cause of death and residual damage as well as disability after electric shock.

A Novel Animal Model Simulating the Beginning of Combat Exposure

OBJECTIVE

Predator stress, social defeat stress, and fear conditioning animal models have been applied to investigate combat-related posttraumatic stress disorder (PTSD). However, no animal model psychopharmacological studies have investigated prevention of somatization of increased mental stress and fatigue at the beginning of combat exposure. This study utilized a novel animal model simulating the beginning of combat exposure that aided specification of a set of biomarkers.

METHODS

Psychological stress was induced by both inescapable electric foot shock and noise stimuli. Physical fatigue was induced by sleep deprivation and forced exercise in a rotating cage. A new device reflecting simultaneous psychological stress and physical fatigue was constructed. The protocol simulating combat exposure was set as 3 rounds of 24-h exposure in a 2-week period, which was specified as intermittent unpredictable stress (IUS).

RESULTS

Mice exposed to IUS (IUS mice) had significantly higher serum corticosterone levels (p < 0.05), excessive locomotive activity (p < 0.001), and anxiety-like behavior (p < 0.02) compared to control mice. IUS mice also had significantly higher IFN-γ (p < 0.001) and TNF-α (p < 0.05) levels in the supernatant of splenic T-cell culture compared to control mice. Brain-derived neurotropic factor levels were significantly decreased (p < 0.04) after IUS exposure.

CONCLUSION

The proposed animal model of combat exposure reflected cognitive function impairment, behavior disturbance, and altered neuroimmune interactions without any apparent histopathological changes, and this animal model may be more applicable to protective research on war syndrome than combat-related PTSD after war because the hypothalamic-pituitary-adrenal axis has not been blunted.

Facial nerve stimulation following cochlear implantation for X-linked stapes gusher syndrome leading to identification of a novel POU3F4 mutation

We report a case of a nine-year-old male who presented with facial nerve stimulation four years after cochlear implantation. Computed tomography was performed revealing a dilated internal auditory meatus and the cochlear implant electrode was found to be protruding into the fallopian canal at the level of the geniculate ganglion. Subsequent genetic analysis demonstrated X-linked deafness type 2 (DFNX2) caused by a novel c.769C > T nucleotide change in the POU domain, class 3, transcription factor 4 gene (POU3F4). Inactivation of electrodes 1 and 19-21 successfully abated facial nerve stimulation.

Transthoracic ventricular fibrillation charge thresholds

Standards, including IEC 60479-1 and -2, provide current-based ventricular fibrillation thresholds (VFT) for stimuli durations between 0.1 ms and 10 s. It has been established that the amount of electrical charge, not the current calculated by root-mean-square, is most representative of the effects of cardiac stimulation. There are no unified models that present transthoracic charge VFTs for a wide range of stimuli durations. This work proposes a new unified charge model applicable to transthoracic stimuli durations ranging over 1 μs - 300 s. VFTs were compiled from our previous animal work and from other published reports, including from the studies that provided the raw data for IEC 60479-1 and -2. Our study goal was to cover a wide range of stimuli durations, for which reliable data exists. Consistent data were found for stimuli durations covering the range of 1 μs - 300 s where VFTs were expressed as charge. The model predicted a transthoracic charge VFT of 1 mC at 1 μs duration. The charge VFT increased with stimulus duration and reached 10 C at 300 s. Presenting the first charge-based transthoracic VFT model covering stimuli durations over 1 μs - 300 s, we found 3 behavioral regions of charge VFT vs.

DURATION

For short stimuli durations, 1 μs - 10 ms, VFTs followed a classic Weiss charge strength-duration curve. For long stimuli, longer than 5 s, charge VFTs can be approximated using a 38 mArms constant current model. From 10 ms to 5 s, charge VFTs tracked through a transition zone that could be approximated as a constant charge model Q≈100 mC.

Suppression of Pain and the R2 Component of the Blink Reflex During Optokinetic Stimulation

The effect of exposure to a rotating optokinetic drum on the electrically evoked blink reflex was investigated in 20 healthy volunteers. Pain ratings and the area under the curve of the R2 component of the blink reflex to innocuous and nociceptive trigeminal stimulation decreased substantially during and after optokinetic stimulation. At low shock intensities, R2 decreased most during optokinetic stimulation in subjects who did not develop symptoms of motion sickness. In contrast, during the recovery period after optokinetic stimulation, suppression of R2 to moderate and intense stimuli was greatest in the most nauseated subjects. These Findings suggest that a mechanism that suppresses symptoms of motion sickness during sensory conflict also inhibits activity in wide dynamic range neurones in the trigeminal nucleus caudalis. Nausea in the absence of sensory conflict may inhibit R2 to intense electrical stimulation by provoking diffuse noxious inhibitory controls.

Repeated 6-Hz Corneal Stimulation Progressively Increases FosB/ΔFosB Levels in the Lateral Amygdala and Induces Seizure Generalization to the Hippocampus

Exposure to repetitive seizures is known to promote convulsions which depend on specific patterns of network activity. We aimed at evaluating the changes in seizure phenotype and neuronal network activation caused by a modified 6-Hz corneal stimulation model of psychomotor seizures. Mice received up to 4 sessions of 6-Hz corneal stimulation with fixed current amplitude of 32 mA and inter-stimulation interval of 72 h. Video-electroencephalography showed that evoked seizures were characterized by a motor component and a non-motor component. Seizures always appeared in frontal cortex, but only at the fourth stimulation they involved the hippocampus, suggesting the establishment of an epileptogenic process. Duration of seizure non-motor component progressively decreased after the second session, whereas convulsive seizures remained unchanged. In addition, a more severe seizure phenotype, consisting of tonic-clonic generalized convulsions, was predominant after the second session. Immunohistochemistry and double immunofluorescence experiments revealed a significant increase in neuronal activity occurring in the lateral amygdala after the fourth session, most likely due to activity of principal cells. These findings indicate a predominant role of amygdala in promoting progressively more severe convulsions as well as the late recruitment of the hippocampus in the seizure spread. We propose that the repeated 6-Hz corneal stimulation model may be used to investigate some mechanisms of epileptogenesis and to test putative antiepileptogenic drugs.

Transthoracic cardiac stimulation thresholds for short pulses

INTRODUCTION

The most common cause of death due to electric shock is ventricular fibrillation (VF). This work reviews applicable results from the literature and provides an estimation model for the risk of VF with short-duration pulses.

METHODS AND RESULTS

For 1 ms pulses, the predicted current and charge thresholds required for successful transthoracic cardiac stimulation were 1.12 A and 1.12 mC, respectively. For pulses of 0.1 ms durations, the transthoracic current and charge thresholds predicted by the model are 10.9 A and 1.09 mC, respectively.

CONCLUSION

In humans, the charge required for single-response cardiac capture using transthoracic electrodes and 0.1 ms pulses is at least 0.5 mC. The transthoracic charge required to trigger repetitive ventricular responses in humans is at least several times higher than that for single responses. Hence, in adult humans, the transthoracic charge threshold required to induce repetitive ventricular responses, tachycardia, or fibrillation, with 0.1 ms pulses is expected to be significantly greater than 1 mC.

[New studies question the cardiac safety of conducted electrical weapons]

Conducted electrical weapons (CEW) were invented in the 1970s and are now widely used by more than 16,000 military and law enforcement agencies worldwide. Recent studies have sug-gested that a causal relation of cardiac arrest in humans and utilization of CEW may exist and cardiac capture and fatal arrhythmia have been documented in animal studies. We believe, based on current knowledge, that CEW use may have caused human fatalities. Users should be aware of potential serious side effects and be able to provide basic life support.

[Effect of melatonin on lipid peroxidation in the blood of rats with various behavioral characteristics during acute emotional stress]

This work was designed to study the effect of melatonin on lipid peroxidation in the peripheral blood of behaviorally passive and active Wistar rats. Immobilization of rats with simultaneous electrocutaneous stimulation (1 h) served as a model of acute stress. After intraperitoneal injection of melatonin (2 mg/kg) the intensity of lipid peroxidation in the blood plasma remained practically unchanged in passive specimens, but increased in active animals. Stress exposure was followed by specific variations in free radical processes in the blood (passive rats, inhibition; active specimens, no changes). Administration of melatonin contributed to a decrease in the intensity of lipid peroxidation in the blood of stressed rats (as compared to control specimens receiving this neurohormone). Therefore, the effect of melatonin on free radical processes depends on the initial behavioral characteristics and physiological state of animals. These data illustrate the importance of an individual approach to studying the systemic mechanisms for organization of functions in mammals. Key words: melatonin, emotional stress, lipid peroxidation, blood plasma, rats with various behavioral characteristics.

Experimentally induced stress validated by EMG activity

Experience of stress may lead to increased electromyography (EMG) activity in specific muscles compared to a non-stressful situation. The main aim of this study was to develop and validate a stress-EMG paradigm in which a single uncontrollable and unpredictable nociceptive stimulus was presented. EMG activity of the trapezius muscles was the response of interest. In addition to linear time effects, non-linear EMG time courses were also examined. Taking into account the hierarchical structure of the dataset, a multilevel random regression model was applied. The stress paradigm, executed in N = 70 subjects, consisted of a 3-minute baseline measurement, a 3-minute pre-stimulus stress period and a 2-minute post-stimulus phase. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. EMG activity during the entire experiment was conform a priori expectations: the pre-stimulus phase showed a significantly higher mean EMG activity level compared to the other two phases, and an immediate EMG response to the stimulus was demonstrated. In addition, the analyses revealed significant non-linear EMG time courses in all three phases. Linear and quadratic EMG time courses were significantly modified by subjective anticipatory stress level, measured just before the start of the stress task. Linking subjective anticipatory stress to EMG stress reactivity revealed that subjects with a high anticipatory stress level responded with more EMG activity during the pre-stimulus stress phase, whereas subjects with a low stress level showed an inverse effect. Results suggest that the stress paradigm presented here is a valid test to quantify individual differences in stress susceptibility. Further studies with this paradigm are required to demonstrate its potential use in mechanistic clinical studies.

TASERS in healthcare: myths and merits

The author, who has trained thousands of police and civilians in use-of-force, tackles the controversy over the use of CEW technology (TASERS) in healthcare settings. In this article he provides the latest technical developments for such weapons, dispels three common myths about them, and provides fresh perspective for further discussion and consideration of their use in healthcare security.

Effectiveness of bisphosphonate analogues and functional electrical stimulation on attenuating post-injury osteoporosis in spinal cord injury patients- a systematic review and meta-analysis

BACKGROUND

Various pharmacologic and non-pharmacologic approaches have been applied to reduce sublesional bone loss after spinal cord injury (SCI), and the results are inconsistent across the studies. The objective of this meta-analysis was to investigate whether the two most-studied interventions, bisphosphonate analogues and functional electrical stimulation (FES), could effectively decrease bone mineral density (BMD) attenuation and/or restore lost BMD in the SCI population.

METHODS

Randomized controlled trials, quasi-experimental studies, and prospective follow-up studies employing bisphosphonates or FES to treat post-SCI osteoporosis were identified in PubMed and Scopus. The primary outcome was the percentage of BMD change from baseline measured by dual-energy X-ray absorptiometry (DEXA) or computed tomography (CT). Data were extracted from four points: the 3rd, 6th, 12th, and 18th month after intervention.

RESULTS

A total of 19 studies were included in the analysis and involved 364 patients and 14 healthy individuals. Acute SCI participants treated with bisphosphonate therapy demonstrated a trend toward less bone loss than participants who received placebos or usual care. A significant difference in BMD decline was noted between both groups at the 3rd and 12th month post-medication. The subgroup analysis failed to show the superiority of intravenous bisphosphonate over oral administration. Regarding FES training, chronic SCI patients had 5.96% (95% CI, 2.08% to 9.84%), 7.21% (95%CI, 1.79% to 12.62%), and 9.56% (95% CI, 2.86% to 16.26%) increases in BMD at the 3rd, 6th, and 12th months post-treatment, respectively. The studies employing FES ≥ 5 days per week were likely to have better effectiveness than studies using FES ≤ 3 days per week.

CONCLUSIONS

Our meta-analysis indicated bisphosphonate administration early following SCI effectively attenuated sublesional bone loss. FES intervention for chronic SCI patients could significantly increase sublesional BMD near the site of maximal mechanical loading.

Catheter-based renal sympathetic denervation significantly inhibits atrial fibrillation induced by electrical stimulation of the left stellate ganglion and rapid atrial pacing

Background

Sympathetic activity involves the pathogenesis of atrial fibrillation (AF). Renal sympathetic denervation (RSD) decreases sympathetic renal afferent nerve activity, leading to decreased central sympathetic drive. The aim of this study was to identify the effects of RSD on AF inducibility induced by hyper-sympathetic activity in a canine model.

Methods

To establish a hyper-sympathetic tone canine model of AF, sixteen dogs were subjected to stimulation of left stellate ganglion (LSG) and rapid atrial pacing (RAP) for 3 hours. Then animals in the RSD group (n = 8) underwent radiofrequency ablation of the renal sympathetic nerve. The control group (n = 8) underwent the same procedure except for ablation. AF inducibility, effective refractory period (ERP), ERP dispersion, heart rate variability and plasma norepinephrine levels were measured at baseline, after stimulation and after ablation.

Results

LSG stimulation combined RAP significantly induced higher AF induction rate, shorter ERP, larger ERP dispersion at all sites examined and higher plasma norepinephrine levels (P<0.05 in all values), compared to baseline. The increased AF induction rate, shortened ERP, increased ERP dispersion and elevated plasma norepinephrine levels can be almost reversed by RSD, compared to the control group (P<0.05). LSG stimulation combined RAP markedly shortened RR-interval and standard deviation of all RR-intervals (SDNN), Low-frequency (LF), high-frequency (HF) and LF/HF ratio (P<0.05). These changes can be reversed by RSD, compared to the control group (P<0.05).

Conclusions

RSD significantly reduced AF inducibility and reversed the atrial electrophysiological changes induced by hyper-sympathetic activity.

Depressive attribution style and stressor uncontrollability increase perceived pain intensity after electric skin stimuli in healthy young men

BACKGROUND

Depressive and pain symptoms often occur concurrently in patients with psychiatric disorders or somatic diseases, but the contribution of pre-existing dysfunctional cognitive schemata to pain perception remains unclear.

OBJECTIVE

To investigate the relationship between depression-related attribution styles and perceived pain intensity (PPI) after controllable versus uncontrollable electrical skin stimulation in healthy male individuals.

METHODS

Causal attributions for negative events were measured using the attribution style questionnaire (ASQ) on the dimensions internal versus external (INT), global versus specific (GLO) and stable versus unstable (STA) in 50 men (20 to 31 years of age). Additionally, symptoms of anxiety and depression (measured using the depression scale) as well as baseline helplessness were assessed. Participants were randomly assigned to receive self-administered (controllable) or experimenter-administered (uncontrollable) painful skin stimuli. PPI was assessed after stress exposure using a visual analogue scale (0 to 100). Relationships between PPI and depression-related cognitions were calculated using correlation and multiple regression analyses.

RESULTS

Correlation analyses revealed a moderate correlation between PPI and ASQ-INT scores (r=0.46). Following uncontrollable stress exposure, significantly higher PPI ratings (P=0.001) and a higher correlation between PPI and ASQ-INT (r=0.70) were observed. Multiple regression analysis showed an independent influence of stressor controllability (ß=0.39; P=0.003) and ASQ-INT (ß=0.36; P=0.006) on PPI.

DISCUSSION

These findings highlight the interaction of specific depression-related cognitions and stress controllability on pain intensity perception.

CONCLUSIONS

The results of the present study may facilitate understanding of the cognitive aspects of pain intensity perception and improve psychological pain therapies focusing on attributions and controllability.

Flexible, transparent, and noncytotoxic graphene electric field stimulator for effective cerebral blood volume enhancement

Enhancing cerebral blood volume (CBV) of a targeted area without causing side effects is a primary strategy for treating cerebral hypoperfusion. Here, we report a new nonpharmaceutical and nonvascular surgical method to increase CBV. A flexible, transparent, and skin-like biocompatible graphene electrical field stimulator was placed directly onto the cortical brain, and a noncontact electric field was applied at a specific local blood vessel. Effective CBV increases in the blood vessels of mouse brains were directly observed from in vivo optical recordings of intrinsic signal imaging. The CBV was significantly increased in arteries of the stimulated area, but neither tissue damage nor unnecessary neuronal activation was observed. No transient hypoxia was observed. This technique provides a new method to treat cerebral blood circulation deficiencies at local vessels and can be applied to brain regeneration and rehabilitation.

Inactivation of mechano-sensitive dilatation upon repetitive mechanical stimulation of the musculo-vascular network in the rabbit

Mechano-sensitivity of the vascular network is known to be implicated in the rapid dilatation at the onset of exercise, however, it is not known how this mechanism responds to repetitive mechanical stimulation. This study tests the hypothesis that the mechanically-induced hyperaemia undergoes some attenuation upon repetitive stimulation. Muscle blood flow was recorded from 9 masseteric arteries (5 right, 4 left) in 6 anesthetized rabbits. Two mechanical stimuli, masseter muscle compression (MC) and occlusion of the masseteric artery (AO), were provided in different combinations: A) repeated stimulation (0.5 Hz, for 40 s); B) single stimuli delivered at decreasing inter-stimulus interval (ISI) from 4 min to 2 s, C) single AO delivered before and immediately after a series of 20 MCs at 0.5 Hz, and vice-versa. Repetitive AO stimulation at 0.5 Hz produced a transient hyperaemia (378 ±189%) peaking at 4.5 ±1.4 s and then decaying before the end of stimulation. The hyperaemic response to individual AOs progressively decreased by 74 ±39% with decreasing ISI from 4 min to 2 s (p<0.01). Non significant differences were observed between AO and MC stimulation. Decreased response to AO was also provoked by previous repetitive MC stimulation, and vice-versa. The results provide evidence that the mechano-sensitivity of the vascular network is attenuated by previous mechanical stimulation. It is suggested that the mechano-sensitive dilatory mechanisms undergoes some inactivation whose recovery time is in the order of a few minutes.

Dissociation between implicit and explicit responses in postconditioning UCS revaluation after fear conditioning in humans

The nature of the relationship between explicit and implicit learning is a topic of considerable debate. To investigate this relationship we conducted two experiments on postconditioning revaluation of the unconditional stimulus (UCS) in human fear conditioning. In Experiment 1, the intensity of the UCS was decreased after acquisition for one group (devaluation) and held constant for another group (control). A subsequent test revealed that even though both groups exhibited similar levels of UCS expectancy, the devaluation group had significantly smaller conditional skin conductance responses. The devaluation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. In Experiment 2, the value of the UCS was increased after acquisition for one group (inflation) and held constant for another group (control). Test performance revealed that UCS inflation did not alter expectancy ratings, but the inflation group exhibited larger learned skin conductance responses than the control group. The inflation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. The SCR revaluation effect was not dependent on explicit memory processes in either experiment. In both experiments we found differences on an implicit measure of learning in the absence of changes in explicit measures. Together, the differences observed between expectancy measures and skin conductance support the idea that these responses might reflect different types of memory formed during the same training procedure and be supported by separate neural systems.