Mechanisms of electroacupuncture relieves uterine smooth muscle spasm in dysmenorrhea rats based on Rho/ROCK signaling pathway. / 基于Rho/ROCKä¿¡å·é€šè·¯æŽ¢è®¨ç”µé’ˆä»»è„‰ã€ç£è„‰ç»ç©´ç¼“è§£ç±»ç—›ç»æ¨¡åž‹å¤§é¼ å­å®«å¹³æ»‘è‚Œç—‰æŒ›çš„æœºåˆ¶.

OBJECTIVES: To investigate the effect of electroacupuncture (EA) on Rho/Rho-associated coiled-coil-forming kinases (ROCK) signaling pathway of uterus tissue in rats with dysmenorrhea, so as to explore the underlying mechanism of EA treating primary dysmenorrhea (PD) and uterine smooth muscle spasm, and to observe whether there is a difference in the effect of meridian acupoints in Conception Vessel (CV) and Governer Vessel (GV). METHODS: Sixty female SD rats were randomly divided into saline, model, CV, GV, and non-acupoint groups, with 12 rats in each group. The dysmenorrhea model was established by subcutaneous injection of estradiol diphenhydrate combined with intraperitoneal injection of oxytocin (OT). EA (2 Hz) was applied to "Qihai" (CV6) and "Zhongji" (CV3) for CV group, "Mingmen" (GV4) and "Yaoshu" (GV2) for GV group, "non-acupoint 1" and "non-acupoint 3" on the left side for non-acupoint group, and manual acupuncture was applied to "Guanyuan" (CV4) for CV group, "Yaoyangguan" (GV3) for GV group, "non-acupoint 2" on the left side for non-acupoint group. The treatment was conducted for 20 min each time, once daily for 10 days. The writhing score was evaluated. The smooth myoelectric signals of rats' uterus in vivo were recorded by multi-channel physiological recorder. The uterine histopathological changes were observed by HE staining. The contents of prostaglandin F2α (PGF2α), OT and calcium ion (Ca2+) in uterine tissue of rats were detected by ELISA. The protein and mRNA expression levels of smooth muscle 22-α (SM22-α), RhoA and ROCKⅡ in uterine tissue were detected by Western blot and fluorescence quantitative PCR, respectively. RESULTS: Compared with the saline group, the writhing score of rats in the model group was increased (P<0.01), the amplitude voltage of uterine smooth muscle in vivo was elevated (P<0.01), the contents of PGF2α, OT and Ca2+, the protein and mRNA expression of SM22-α, RhoA and ROCK Ⅱ in uterine tissue were all increased (P<0.01). Compared with the model and the non-acupoint groups, the writhing scores of the CV and the GV groups were decreased (P<0.01, P<0.05), the amplitude voltage of uterine smooth muscle was decreased (P<0.01), the contents of PGF2α, OT and Ca2+ in uterine tissue were decreased (P<0.01, P<0.05), and the protein expression and mRNA expression of SM22-α, RhoA and ROCKⅡ in uterine tissue were decreased (P<0.01, P<0.05). HE staining showed extensive exfoliation of uterine intima with severe edema and increased glandular secretion in the model group, which was alleviated in the CV and GV groups. CONCLUSIONS: EA at acupoints of CV and GV can significantly reduce the writhing score, uterine smooth muscle amplitude voltage, pathological injury degree of uterus, and relieve spasm of uterine smooth muscle in dysmenorrhea rats, which may be related to its effect in regulating PGF2α and OT contents, inhibiting the Rho/ROCK signaling pathway, and reducing the SM22-α, RhoA, ROCKⅡ protein and mRNA expression, and Ca2+ content in uterine tissue.

Oral IBGard™ Before Colonoscopy: A Single-Center Double-Blinded, Randomized, Placebo-Controlled Trial.

BACKGROUND: Peppermint oil is well known to inhibit smooth muscle contractions, and its topical administration during colonoscopy is reported to reduce colonic spasms. AIMS: We aimed to assess whether oral administration of IBGard™, a sustained-release peppermint oil formulation, before colonoscopy reduces spasms and improves adenoma detection rate (ADR).  METHODS: We performed a single-center randomized, double-blinded, placebo-controlled trial. Patients undergoing screening or surveillance colonoscopies were randomized to receive IBGard™ or placebo. The endoscopist graded spasms during insertion, inspection, and polypectomy. Bowel preparation, procedure time, and time of drug administration were documented. Statistical analysis was performed using the Student's t test and Wilcoxon rank-sum test. RESULTS: There was no significant difference in baseline characteristics or dose-timing distribution between IBGard™ and placebo groups. Similarly, there was no difference in ADR (IBGard™ = 47.8%, placebo = 43.1%, p = 0.51), intubation spasm score (1.23 vs 1.2, p = 0.9), withdrawal spasm score (1.3 vs 1.23, p = 0.72), or polypectomy spasm score (0.52 vs 0.46, p = 0.69). Limiting the analysis to patients who received the drug more than 60 min prior to the start of the procedure did not produce any significant differences in these endpoints. CONCLUSIONS: This randomized controlled trial failed to show benefit of orally administered IBGard™ prior to colonoscopy on the presence of colonic spasms or ADR. Because of its low barrier to widespread adoption, the use of appropriately formulated and timed oral peppermint oil warrants further study to determine its efficacy in reducing colonic spasms and improving colonoscopy quality.

Neocortical Slow Oscillations Implicated in the Generation of Epileptic Spasms.

OBJECTIVE: Epileptic spasms are a hallmark of severe seizure disorders. The neurophysiological mechanisms and the neuronal circuit(s) that generate these seizures are unresolved and are the focus of studies reported here. METHODS: In the tetrodotoxin model, we used 16-channel microarrays and microwires to record electrophysiological activity in neocortex and thalamus during spasms. Chemogenetic activation was used to examine the role of neocortical pyramidal cells in generating spasms. Comparisons were made to recordings from infantile spasm patients. RESULTS: Current source density and simultaneous multiunit activity analyses indicate that the ictal events of spasms are initiated in infragranular cortical layers. A dramatic pause of neuronal activity was recorded immediately prior to the onset of spasms. This preictal pause is shown to share many features with the down states of slow wave sleep. In addition, the ensuing interictal up states of slow wave rhythms are more intense in epileptic than control animals and occasionally appear sufficient to initiate spasms. Chemogenetic activation of neocortical pyramidal cells supported these observations, as it increased slow oscillations and spasm numbers and clustering. Recordings also revealed a ramp-up in the number of neocortical slow oscillations preceding spasms, which was also observed in infantile spasm patients. INTERPRETATION: Our findings provide evidence that epileptic spasms can arise from the neocortex and reveal a previously unappreciated interplay between brain state physiology and spasm generation. The identification of neocortical up states as a mechanism capable of initiating epileptic spasms will likely provide new targets for interventional therapies. ANN NEUROL 2021;89:226-241.

Amelioration of muscular spasm-induced pain of Guangtongxiao recipe in a non-everted gut sac in vitro model.

BACKGROUND: The modern study of the traditional Chinese medicine (TCM) compound recipes is a complex issue because of the large number of components in the recipes that would produce several metabolites after entering the body. The TCM compound recipes are known to have the advantage of synergistic treatment by multiple targets due to diverse components. Therefore, a research method that can reflect the overall effect of compounds with multi-components is essential. The pharmacological studies of the classic TCM compound recipes mainly use the sero-pharmacological method. It is a semi-in vivo study method, and the drug to be tested in the in vitro experiment is the drug-containing serum from the model animals (the drug to be tested is a mixed drug system containing the prototype drugs in animal bodies that have pharmacodynamic effects and the metabolites). Herein, a safe and effective external TCM recipe was used to develop another semi-in vivo experimental method to reflect the overall effects of TCM. AIM: To observe the effects of in-vitro intestinal absorption liquid of aqueous extracts of the TCM compound recipe-Guangtongxiao foam aerosol (Guangtongxiao)-on the tension of isolated rectal rings of mouse and investigate the underlying mechanisms of antispasmodic and amelioration of muscular spasm-induced pain. METHODS: Intestinal absorption liquid of the Guangtongxiao aqueous extract at the five time points (30, 45, 75, 105, and 120 min) was prepared using a non-everted gut sac method. The isolated rectal rings of mice were prepared by pre-contraction using potassium chloride (KCl) or acetylcholine chloride (ACh) to make steady contraction. The intestinal absorption liquid were added cumulatively to the sink with the constricted rectal rings. The effects of the five groups of the intestinal absorption liquid with different drug concentration were observed on the tension of the isolated rectal rings. Then the ex vivo perfusion of the mouse rectal ring was performed as same as Guangtongxiao intestinal absorption liquid experiments, and the effects of two major components of Guangtongxiao, paeoniflorin (Pae) and tetrahydropalmatine (THP), on the rectal ring pre-treated with high concentration of KCl and ACh to induce contraction were studied. RESULTS: The relaxation rate of the five groups of the intestinal canals increased significantly with 3200 µL cumulative sample volume as compared to the blank group (P < 0.01). It suggested that the relaxation activity of the intestinal absorption liquid enhanced significantly with the prolongation of the interaction between isolated rectal rings and intestinal absorption liquid in a time-dependent manner. Also, significant differences were detected while comparing between the 120-min intestinal absorption liquid group and the blank group with respect to various cumulative sampling volumes (P < 0.01). In addition, the intestinal relaxation rate elevated gradually with the increase in sampling volume, indicating that the concentrations of active substances in the intestinal absorption liquid prepared by the non-everted gut sac model increased and the intestinal relaxation activity was enhanced with the prolongation of the absorption time in a dose-dependent manner. And Pae and THP in a concentration-dependent manner caused relaxation of the rectal ring, which is pretreated with high K+(KCl) and ACh to induce contraction. The EC50 of Pae and THP was 8.67 × 10-5 M (6.68 × 10-5-1.13 × 10-4) and 1.41 × 10-4 M (1.24 × 10-4-1.61 × 10-4) in the contraction model induced by KCl, and was 6.15 × 10-5 M (4.47 × 10-5-8.45 × 10-5), and 1.31 × 10-4 M(1.22 × 10-4-1.42 × 10-4) in the model induced by ACh, respectively. CONCLUSION: The intestinal absorption liquid of Guangtongxiao exerted a remarkable relaxation activity for the rectal rings, and relaxation of the smooth muscle tension might be one of the antispasmodic mechanisms of Guangtongxiao compound recipe. Also, adopting a semi-in-vivo experimental method to study the efficacy of topical external TCM recipe medicine is optimal.

Acupuncture of fascia points to relieve hand spasm after stroke: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: The loss of functional ability of patients after stroke is mostly caused by dysfunction of the upper limbs, especially the hands. Hand functional exercise is the premise of alleviating hand dysfunction, and the relief of hand spasm is the basis of timely and effective hand functional exercise. Previous clinical observation have shown that fascial-point needling can effectively alleviate hand spasm immediately after stroke, but further evidence from large-sample studies is needed. The overall objective of this trial is to further evaluate the clinical efficacy of fascial-point acupuncture on hand spasm after stroke. METHODS/DESIGN: This multicenter randomized controlled trial will compare the efficacy of fascial-point acupuncture versus sham acupuncture and routine rehabilitation therapy in stroke patients with hand spasm. Patients will be randomized to undergo either the fascial-point acupuncture, the sham acupuncture or the control (routine rehabilitation therapy). We will recruit 210 stroke inpatients who meet the trial criteria and observe the remission of hand spasm and improvement of limb function after 4 weeks of intervention. The first evaluation indices are the remission of hand spasm and the duration of spasm remission. The second evaluation indices are the hand function of the affected limbs and the activities of daily living. When the accumulative total number of cases included reaches 120, a mid-term analysis will be conducted to determine any evidence that experimental intervention does have an advantage. DISCUSSION: Our aim is to evaluate the efficacy of fascial-point acupuncture in relieving hand spasm after stroke. The results should provide more evidence for the clinical application of this therapy in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ID: ChiCTR1900022379. Registered on 9 April 2019.

Functional outcome after the nonsurgical treatment for adolescent spasmodic valgus foot.

BACKGROUND: Adolescent spasmodic valgus foot is usually associated with resistant pain and deformity. It shows controversy regarding its incidence, etiology, and treatment. Our study aimed to evaluate the functional outcome after the nonsurgical treatment for such condition. METHODS: This study included 50 planovalgus feet secondary to peroneal or peroneo-extensor spasm in 33 adolescents with a mean age of 14 ± 2.8 years. The procedure included foot manipulation under general anesthesia, sinus tarsi injection with corticosteroids, and a walking cast in the neutral position. Patients were evaluated functionally (using the American Orthopedic Foot and Ankle Society (AOFAS)) and radiologically before the procedure, after cast removal, and 3, 9, and 18 months later with special attention given for recurrence during the follow-up period with a mean duration of 22.5 ± 3.5 months. RESULTS: Once general anesthesia had been conducted, the deformity was corrected without any manipulation, and full passive inversion could be easily obtained in 26 feet, the deformity was corrected only after manipulation, and full passive inversion had been obtained in 14 feet, while 10 feet remained stiff even after manipulation. The mean AOFAS score was significantly improved ( p < 0.001) from 40.9 ± 3.5 at presentation to 73.56 ± 5.2 at the last follow-up in which 12 feet was painless and freely mobile and 24 feet had partial relapse, while 14 feet had complete relapse. CONCLUSION: The nonsurgical treatment for adolescent spasmodic valgus foot could be a simple and effective treatment. Apart from limited complete recurrence, the overall functional outcome was satisfactory. Level of evidence: type IV case series.

Prolotherapy for the Thoracolumbar Myofascial System.

Prolotherapy has focused on entheses as a key source of chronic low back pain, even without clear diagnosis of enthesopathy. Treatment has traditionally been guided by anatomic knowledge and careful palpation. This article integrates ultrasonographic diagnosis of fascial injury with examination findings taught in traditional prolotherapy technique. Thoracolumbar fascial anatomy and biotensegrity theory are used to explain patient presentation and response to treatment at these pathologic findings. Detailed case reports provide proof of concept for the 60-year history of prolotherapy in the treatment of chronic low back pain.

[Efficacy on the range of motion of the lower limbs in patients of post-stroke spasmodic paralysis regulated with multi-directional stimulation technique].

OBJECTIVE: To compare the efficacy between the multi-directional stimulation technique and routine needling technique in the range of motion (ROM) of the lower limbs in patients of post-stroke spasmodic paralysis. METHODS: Sixty patients were randomized into a multi-directional stimulation technique group and a routine needling technique group, 30 cases in each one. In the two groups, Biguan (ST 31), Fengshi (GB 31), Yang-lingquan (GB 34), Xiyangguan (GB 33), Zhongfeng (LR 4), Jiexi (ST 41), Qiuxu (GB 40), Kunlun (BL 60) and Xuanzhong (GB 39) on the affected side, scalp acupuncture sites and the acupoints on the upper limb of the affected side were selected. The even needling technique was used in the routine needling technique group and the multi-directional stimulation technique was used in the multi-directional stimulation technique group. The treatment was given once daily, 5 days a week, for 4 weeks totally. Before and after treatment, Fugl-Meyer function and Berg balance were scored. The three-dimensional gait analysis was adopted to analyze ROM of hip, knee and ankle joints. RESULTS: Fugl-Meyer function score and Berg balance score were improved significantly after treatment as compared with those before treatment in the two groups (all P<0.01). The scores in the multi-directional stimulation technique group were all higher than those in the routine needling technique group (P<0.01, P<0.05). The abduction and adduction of hip joints and flexion-extension ROM were all improved after treatment as comparedwith those before treatment in the two groups (all P<0.05). The maximum flexibility and flexion extension ROM of knee joint were improved after treatment as compared with those before treatment in the two groups (all P<0.05), and the changes in extension of knee joint were not apparent (both P>0.05). After treatment, the maximal flexion and the flexion-extension ROM of knee joint in the multi-directional stimulation technique group were improved significantly as compared with those in the routine needling technique group (both P<0.05). The maximal dorsal flexion of ankle joint in the multi-directional stimulation technique group after treatment was increased as compared with that before treatment (P<0.05), and the change was better than that in the routine needling technique group (P<0.05). CONCLUSIONS: Acupuncture effectively increases the maximal adduction angle and flexion-extension ROM of hip joint, and reduces abduction of hip joint. The multi-directional stimulation technique contributes to the flexion of knee joint and dorsal flexion of ankle joint and the maintenance of limb balance. The efficacy of it is better than that of routine acupuncture stimulation technique.

Effect of electroacupuncture on muscle state and infrared thermogram changes in patients with acute lumbar muscle sprain.

OBJECTIVE: To observe the effect of electroacupuncture (EA) on force-displacement value (FDV) of muscle state and the temperature index of infrared thermogram in patients with acute lumbar muscle sprain. METHODS: Patients with acute lumbar muscle sprain were randomly divided into a medication group and an EA group. The medication group (n = 60) were treated with diclofenac sodium dual release enteric-coated capsules, 75 mg per day for 7 days. The EA group (n = 60) received EA at bilateral Houxi (SI 3), Jiaji (EX-B2), and Ashi points, at 20-30 mm depth and 10-25 Hz frequency for 20 min daily for 7 days. Muscle states were determined by measuring FDVs of the bilateral lumbar muscle with a Myotonometer fast muscle state detector. The temperature index of the lumbar skin was measured before and after treatment with a Fluke Ti30 non-refrigerated focal plane infrared thermal imaging detector. RESULTS: There were no significant pre-treatment differences between the medication group and the EA group in mean FDV (P = 0.052) or temperature index of the lumbar skin (P = 0.25). The cure rate was 63.3% in the EA group and 53.3% in the medication group. The total efficacy in the EA group (93.3 %) was not significantly different from that in the medication group (86.6 %, P = 0.204). After treatment, the mean FDV of the lumbar muscle significantly increased in both groups (P < 0.05 for both groups); the FDV increase in the EA group was significantly higher than in the medication group (P = 0.015). The temperature index was also significantly increased in both groups (P < 0.05 for both groups); the infrared thermogram in the EA group indicated significantly greater recovery compared to the medication group (P = 0.026). CONCLUSION: Both EA and diclofenac sodium markedly improved acute lumbar sprain, but EA better improved the rehabilitation and regeneration of FDVs and temperature index of infrared thermogram of the muscle.

Effect of low-level laser therapy on the post-surgical inflammatory process after third molar removal: study protocol for a double-blind randomized controlled trial.

BACKGROUND: Low-level laser therapy (LLLT) has been shown to modulate the inflammatory process without adverse effects , by reducing pain and swelling and promoting the repair of damaged tissues. Because pain, swelling and muscle spasm are complications found in virtually all patients following oral surgery for the removal of impacted teeth, this model has been widely used to evaluate the effects of LLLT on the inflammatory process involving bone and, connective tissue and the muscles involved in mastication. METHODS/DESIGN: After meeting the eligibility criteria, 60 patients treated at a Specialty Dental Center for the removal of impacted lower third molars will be randomly divided into five groups according to the type of laser therapy used at the end of surgery (intraoral irradiation with 660 nm laser; extraoral irradiation with 660 nm laser; intraoral irradiation with 808 nm laser; extraoral irradiation with 808 nm laser and no irradiation). To ensure that patients are blinded to the type of treatment they are receiving, the hand piece of the laser apparatus will be applied both intraorally and extraorally to all participants, but the device will be turned on only at the appropriate time, as determined by the randomization process. At 2 and 7 days after surgery, the patients will be evaluated by three blinded evaluators who will measure of swelling, mouth opening (muscle spasm evaluation) and pain (using two different pain scales). The 14-item Oral Health Impact Profile (OHIP-14) will be used to assess QOL. All data will be analyzed with respect to the normality of distribution using the Shapiro-Wilk test. Statistically significant differences between the experimental groups will be determined using analysis of variance, followed by a suitable post hoc test, when necessary. The significance level will be set at α = 0.05. DISCUSSION: The lack of standardization in studies with regard to the samples, methods and LLLT parameters complicates the determination of the actual effect of laser therapy on this model. The present study aims to provide a randomized, controlled, double-blind trial to compare four different LLLT parameters in relation to the outcomes of pain, swelling and muscle spasm following surgery for the extraction of impacted third molars and evaluate the effects os surgery on patients' quality os life (QOL). TRIAL REGISTRATION: Brazilian Registry of Clinical Trials - Rebec (RBR-6XSB5H).

Effects of unilateral facet fixation and facetectomy on muscle spindle responsiveness during simulated spinal manipulation in an animal model.

OBJECTIVES: Manual therapy practitioners commonly assess lumbar intervertebral mobility before deciding treatment regimens. Changes in mechanoreceptor activity during the manipulative thrust are theorized to be an underlying mechanism of spinal manipulation (SM) efficacy. The objective of this study was to determine if facet fixation or facetectomy at a single lumbar level alters muscle spindle activity during 5 SM thrust durations in an animal model. METHODS: Spinal stiffness was determined using the slope of a force-displacement curve. Changes in the mean instantaneous frequency of spindle discharge were measured during simulated SM of the L6 vertebra in the same 20 afferents for laminectomy-only and 19 laminectomy and facet screw conditions; only 5 also had data for the laminectomy and facetectomy condition. Neural responses were compared across conditions and 5 thrust durations (≤ 250 milliseconds) using linear-mixed models. RESULTS: Significant decreases in afferent activity between the laminectomy-only and laminectomy and facet screw conditions were seen during 75-millisecond (P < .001), 100-millisecond (P = .04), and 150-millisecond (P = .02) SM thrust durations. Significant increases in spindle activity between the laminectomy-only and laminectomy and facetectomy conditions were seen during the 75-millisecond (P < .001) and 100-millisecond (P < .001) thrust durations. CONCLUSION: Intervertebral mobility at a single segmental level alters paraspinal sensory response during clinically relevant high-velocity, low-amplitude SM thrust durations (≤ 150 milliseconds). The relationship between intervertebral joint mobility and alterations of primary afferent activity during and after various manual therapy interventions may be used to help to identify patient subpopulations who respond to different types of manual therapy and better inform practitioners (eg, chiropractic and osteopathic) delivering the therapeutic intervention.

Improved dexterity after chronic electrical stimulation of the motor cortex for central pain: a special relevance for thalamic syndrome.

OBJECTIVES: To demonstrate that motor cortex stimulation (MCS) could improve motor function in patients with neuropathic pain. METHODS: In this prospective clinical study of 38 patients referred for MCS as treatment for their neuropathic pain, we collected any declaration of improvement in motor performance that could be attributed to MCS. RESULTS: Ten patients (26%) declared a benefit in their motor function. Eight presented objective evidence of recovered dexterity for rapid alternating movements. A minor proportion had improvement in dystonic posture (n = 2), but none had detectable increased motor strength or tonus changes. Overall, 73% of the patients with limb ataxia declared a benefit after MCS. In 6 out of 10 patients (60%), the anatomic lesion responsible for pain was restricted to the lateral aspect of the thalamus. All of them had either clinical or electrophysiological evidence of lemniscal dysfunction (proprioceptive ataxia). No correlation was found between the scores of pain relief and the modification of motor status. The correlation between thalamic lesions and benefits in motor performance was significant (Fisher's exact test, two-tailed, p = 0.0017). CONCLUSIONS: Up to 26% of patients estimated that MCS improved their motor outcome through recovered dexterity and in cases of lateral thalamic lesions.

Acute repetitive lumbar syndrome: a multi-component insight into the disorder.

PURPOSE: Repetitive Lumbar Injury (RLI) is common in individuals engaged in long term performance of repetitive occupational/sports activities with the spine. The triggering source of the disorder, tissues involved in the failure and biomechanical, neuromuscular, and biological processes active in the initiation and development of the disorder, are not known. The purpose is, therefore, to test, using in-vivo feline model and healthy human subjects, the hypothesis that RLI due to prolonged exposure to repetitive lumbar flexion-extension is triggered by an acute inflammation in the viscoelastic tissues and is characterized by lingering residual creep, pronounced changes in neuromuscular control and transient changes in lumbar stability. This report, therefore, is a summary of a lengthy research program consisting of multiple projects. METHODS: A series of experimental data was obtained from in-vivo feline groups and normal humans subjected to prolonged cyclic lumbar flexion-extension at high and low loads, high and low velocities, few and many repetitions, as well as short and long in-between rest periods, while recording lumbar displacement and multifidi EMG. Neutrophil and cytokines expression analysis were performed on the dissected feline supraspinous ligaments before loading (control) and 7 h post-loading. A comprehensive, time based model was designed to represent the creep, motor control, tissue biology and stability derived from the experimental data. RESULTS: Prolonged cyclic loading induced creep in the spine, reduced muscular activity, triggered spasms and reduced stability followed, several hours later, by acute inflammation/tissue degradation, muscular hyperexcitability and hyperstability. Fast movement, high loads, many repetitions and short rest periods, triggered the full disorder, whereas low velocities, low loads, long rest and few repetitions, triggered only minor but statistically significant pro-inflammatory tissue degradation and significantly reduced stability. CONCLUSION: Viscoelastic tissue failure via inflammation is the source of RLI and is also the process which governs the mechanical and neuromuscular characteristic symptoms of the disorder. The experimental data validates the hypothesis and provides insights into the development of potential treatments and prevention.

A generic model of real-world non-ideal behaviour of FES-induced muscle contractions: simulation tool.

Functional electrical stimulation (FES) applications are frequently evaluated in simulation prior to testing in human subjects. Such simulations are usually based on the typical muscle responses to electrical stimulation, which may result in an overly optimistic assessment of likely real-world performance. We propose a novel method for simulating FES applications that includes non-ideal muscle behaviour during electrical stimulation resulting from muscle fatigue, spasms and tremors. A 'non-idealities' block that can be incorporated into existing FES simulations and provides a realistic estimate of real-world performance is described. An implementation example is included, showing how the non-idealities block can be incorporated into a simulation of electrically stimulated knee extension against gravity for both a proportional-integral-derivative controller and a sliding mode controller. The results presented in this paper illustrate that the real-world performance of a FES system may be vastly different from the performance obtained in simulation using nominal muscle models. We believe that our non-idealities block should be included in future simulations that involve muscle response to FES, as this tool will provide neural engineers with a realistic simulation of the real-world performance of FES systems. This simulation strategy will help engineers and organizations save time and money by preventing premature human testing. The non-idealities block will become available free of charge at www.toronto-fes.ca in late 2011.

Occipital neurostimulation-induced muscle spasms: implications for lead placement.

BACKGROUND: For many headache types, occipital peripheral nerve stimulation (ONS) provides significant relief of chronic, frequent, and severe headaches. Though rarely reported, ONS may cause painful muscle spasms that make stimulator use impractical. The classic description of the technique advocates placement of the leads transversely at the level of the arch of C1 or at C1-2. At that level, the greater occipital nerve (GON) infrequently pierces the superficial fascia of the neck muscles to become superficial. However, important anatomic variability exists. OBJECTIVE: To report placement of leads higher at the nuchal line rather than the classically recommended C1 level to avoid ONS-induced muscle spasm. METHODS: Four interventional pain physicians independently revised ONS leads due to painful muscle stimulation. Five case reports of surgical ONS lead revision for management of ONS-induced muscle spasms are described and discussed. RESULTS: Placement of peripheral neurostimulator leads at or above the nuchal line in these 5 cases provided good paresthesiae without causing neck muscle spasm. CONCLUSION: Lead placement at the level of C1 or C1-2 may cause some patients to have intolerable neck/occipital spasm during neurostimulation. This is the first known published report of technical variation in the location of lead placement, at the nuchal line in a transverse fashion, for ONS. Placing ONS leads at the level of the occipital protuberance appears to eliminate ONS-induced muscle spasm while allowing good paresthesia coverage. LIMITATIONS: Stimulation parameters vary, thus posting parameters may be misleading as muscle spasms occurred despite multiple reprogramming attempts and were a function of lead position, not program settings.