Effects of pulse duration on neuromuscular blockade monitoring: Implications for supramaximal stimulation

Questions have been raised concerning the reliability of surface electrodes in achieving supramaximal stimulation during the monitoring of neuromuscular blockade; needle electrodes are considered reliable in this respect. This study compares interelectrode impedances of needle and surface electrodes during neuromuscular blockade monitoring and suggests those characteristics of the stimulation pulse that can ensure reliable supramaximal stimulation with either type of electrode. Interelectrode voltage and current for surface and needle electrodes were measured by using 1.0-ms pulses at low, medium, and high stimulation levels on 22 surgical patients during anesthesia. Data were collected immediately after electrode application, and again at 10 minutes after application. Stimulation with surface electrodes produced an initial, transient surge of current, followed by a lower steady-state value. At high stimulation levels, the peak transient current was 87% higher than the steady-state current. Needle electrodes produced a constant high-current response. At high stimulation levels the transient impedance of the surface electrode and the impedance of the needle electrode were essentially equal (0.7 k and 0.75 k, respectively). The transient impedance was significantly lower (P<0.001) and was associated with less interpatient variation (P<0.001) and less sensitivity to the duration of electrode application than was the steady-state impedance of the surface electrode. These data suggest that high-current pulses with widths of less than 0.2 ms could provide reliable supramaximal stimulation with either type of electrode.     

Occipital Nerve Stimulation for Migraine: A Systematic Review

Patients who suffer from migraines often report impaired quality of life. Occipital nerve stimulation (ONS) is a novel treatment modality for migraines, although few systematic reviews have evaluated whether this therapy is efficacious. The objective of this study was to evaluate the clinical efficacy and safety of ONS for treating migraine through a literature review. We performed a literature search to identify studies that investigated ONS for migraine treatment. Evidence levels of these studies were assessed by recommendations set by the University of Oxford Centre for Evidence‐Based Medicine. Five randomized controlled trials, 4 retrospective studies, and one prospective study met the inclusion criteria. Results from the retrospective studies and case series indicated that ONS significantly reduced the pain intensity and the number of days with headache in patients with migraine. However, the evidence of ONS efficacy established by randomized controlled trials was limited. Improvement in the migraine disability assessment (MIDAS) score was more dramatic than improvement in the SF‐36 score at follow‐up. The mean complication incidence of ONS was 66% for the reviewed studies. Future clinical studies should optimize and standardize the ONS intervention process and identify the relationship among the surgical process, efficacy, and complications resulting from the procedure.     

电刺激对周围神经再生的影响

周围神经损伤是创伤中常见的并发症，促进周围神经损伤后的再生，恢复其功能已日益成为研究的重点。本文就周围神经损伤的病理变化、周围神经成功再生的条件、电刺激促进周围神经再生的实验及临床研究、电刺激促进周围神经再生的机理进行了综述。目前关于电刺激促进周围神经再生的效应已逐渐得到认可，但电刺激治疗周围神经损伤仍存在着很多未知领域，还需要进一步更深入的研究。     

Vagus Nerve and Vagus Nerve Stimulation,a Comprehensive Review: Part II

The development of vagus nerve stimulation (VNS) began in the 19th century. Although it did not work well initially, it introduced the idea that led to many VNS‐related animal studies for seizure control. In the 1990s, with the success of several early clinical trials, VNS was approved for the treatment of refractory epilepsy, and later for the refractory depression. To date, several novel electrical stimulating devices are being developed. New invasive devices are designed to automate the seizure control and for use in heart failure. Non‐invasive transcutaneous devices, which stimulate auricular VN or carotid VN, are also undergoing clinical trials for treatment of epilepsy, pain, headache, and others. Noninvasive VNS (nVNS) exhibits greater safety profiles and seems similarly effective to their invasive counterpart. In this review, we discuss the history and development of VNS, as well as recent progress in invasive and nVNS.     

Occipital Nerve Blockade for Cervicogenic Headache: A Double-Blind Randomized Controlled Clinical Trial

Abstract:   Cervicogenic headache is a chronic hemicranial pain, usually occurring daily. This randomized, double-blind, placebo-controlled trial evaluated the effectiveness of nerve stimulator-guided occipital nerve blockade in the treatment of cervicogenic headache. The reduction in analgesic consumption was the primary outcome measure. Fifty adult patients diagnosed with cervicogenic headache were randomly divided into two equal groups of 25 patients each. All patients in both groups received greater and lesser occipital blocks, whereas only 16 patients in each group received facial nerve blockade in association with the occipital blocks. The control group received injections of an equivalent volume of preservative-free normal saline. Pain was assessed using the visual analog scale (VAS) and the Total Pain Index (TPI). Forty-seven patients entered into the final analysis as three patients were lost to follow-up. Anesthetic block was effective in reducing the VAS and the TPI by approximately 50% from baseline values ( P  = 0.0001). Analgesic consumption, duration of headache and its frequency, nausea, vomiting, photophobia, phonophobia, decreased appetite, and limitations in functional activities were significantly less in block group compared to control group ( P  < 0.05). The nerve stimulator-guided occipital nerve blockade significantly relieved cervicogenic headache and associated symptoms at two weeks following injection.     

Peripheral Nerve Stimulation for the Treatment of Postamputation Pain—A Case Report

Many amputees suffer from postamputation pain, which can be extremely debilitating, decrease quality of life, increase the risk of depression, and negatively affect interpersonal relationships and the ability to work. Present methods of treatment, including medications, are often unsatisfactory in reducing postamputation pain. Electrical stimulation of the nerve innervating the painful area could reduce the pain, but peripheral nerve stimulation is rarely used to treat postamputation pain because present methods require invasive surgical access and precise placement of the leads in close proximity (≤ 2 mm) with the nerve. The present study investigated a novel approach to peripheral nerve stimulation in which a lead was placed percutaneously a remote distance (> 1 cm) away from the femoral nerve in a patient with severe residual limb pain (RLP) 33 years following a below‐knee amputation. Electrical stimulation generated ≥ 75% paresthesia coverage, reduced RLP by > 60%, and improved quality of life outcomes as measured by the pain interference scale of the Brief Pain Inventory‐Short Form (100% reduction in pain interference), Pain Disability Index (74% reduction in disability), and the Patient Global Impression of Change (very much improved) during a 2‐week home trial. There were no adverse events. The ability to generate significant paresthesia coverage and pain relief with a single lead inserted percutaneously and remotely from the target nerve holds promise for providing relief of postamputation pain.     

Vagus Nerve and Vagus Nerve Stimulation,a Comprehensive Review: Part III

Vagus nerve stimulation (VNS) is currently undergoing multiple trials to explore its potential for various clinical disorders. To date, VNS has been approved for the treatment of refractory epilepsy and depression. It exerts antiepileptic or antiepileptogenic effect possibly through neuromodulation of certain monoamine pathways. Beyond epilepsy, VNS is also under investigation for the treatment of inflammation, asthma, and pain. VNS influences the production of inflammatory cytokines to dampen the inflammatory response. It triggers the systemic release of catecholamines that alleviates the asthma attack. VNS induces antinociception by modulating multiple pain‐associated structures in the brain and spinal cord affecting peripheral/central nociception, opioid response, inflammation process, autonomic activity, and pain‐related behavior. Progression in VNS clinical efficacy over time suggests an underlying disease‐modifying neuromodulation, which is an emerging field in neurology. With multiple potential clinical applications, further development of VNS is encouraging.     

Vagus Nerve and Vagus Nerve Stimulation,a Comprehensive Review: Part I

The vagus nerve (VN), the “great wondering protector” of the body, comprises an intricate neuro‐endocrine‐immune network that maintains homeostasis. With reciprocal neural connections to multiple brain regions, the VN serves as a control center that integrates interoceptive information and responds with appropriate adaptive modulatory feedbacks. While most VN fibers are unmyelinated C‐fibers from the visceral organs, myelinated A‐ and B‐fiber play an important role in somatic sensory, motor, and parasympathetic innervation. VN fibers are primarily cholinergic but other noncholinergic nonadrenergic neurotransmitters are also involved. VN has four vagal nuclei that provide critical controls to the cardiovascular, respiratory, and alimentary systems. Latest studies revealed that VN is also involved in inflammation, mood, and pain regulation, all of which can be potentially modulated by vagus nerve stimulation (VNS). With a broad vagal neural network, VNS may exert a neuromodulatory effect to activate certain innate “protective” pathways for restoring health.     

Neurostimulation for Postsurgical Analgesia: A Novel System Enabling Ultrasound‐Guided Percutaneous Peripheral Nerve Stimulation

While neurostimulation—stimulation of the nervous system using electrical current—has been used to treat chronic pain, its use treating postsurgical pain has been limited. Here, we report on the clinical application of a novel investigational lead to provide analgesia following total knee arthroplasty. In 5 subjects, leads were inserted percutaneously using ultrasound guidance within 0.5 to 3.0 cm of the femoral and/or sciatic nerve(s). With the delivery of current, pain decreased an average of 63% at rest, with 4 of 5 subjects having relief of > 50%. During passive and active knee flexion, pain decreased an average of 14% and 50%, with 0/3 and 1/2 subjects attaining > 50% relief, respectively. Ultrasound‐guided percutaneous peripheral nerve stimulation may be a practical modality for the treatment of postsurgical pain.     

外周神经电刺激引导下A型肉毒毒素注射在痉挛型脑性瘫痪中的应用

目的探讨在外周神经电刺激引导下A型肉毒毒素(BTX-A)局部注射治疗痉挛型脑瘫的疗效。方法共选取30例痉挛型脑瘫患儿,在外周神经电刺激引导下采用BTX-A局部多点注射,于治疗前、后采用改良Ashworth量表(MAS)和粗大运动功能评定量表(GMFM-88)进行评定。结果 BTX-A注射1周后,MAS评分显著降低,并维持至6个月时(P<0.001)。与治疗前相比,注射1周后,GMFM-88评分无显著性差异(P>0.05),3个月和6个月时显著增加(P<0.001)。结论外周神经电刺激引导下BTX-A局部多点注射治疗痉挛型脑瘫疗效显著。     

Migraine Prevention Using Different Frequencies of Transcutaneous Occipital Nerve Stimulation: A Randomized Controlled Trial

This study's objective was to evaluate the efficacy and tolerability of transcutaneous occipital nerve stimulation (tONS) in patients with migraine, and to explore whether different tONS frequencies influenced treatment effectiveness. This was a randomized, controlled trial of tONS for prevention of migraine. Patients were randomized to 1 of 5 therapeutic groups before treatment for 1 month. Groups A through C received tONS at different frequencies (2 Hz, 100 Hz, and 2/100 Hz), group D underwent sham tONS intervention, and group E received topiramate orally. The primary outcomes were the 50% responder rate and headache characteristics. A total of 110 patients completed the study. The 50% responder rate was significantly greater in the groups undergoing active tONS and topiramate, compared with sham-treated group. A significant reduction in headache intensity was noted in each test group compared with the sham group; the groups undergoing tONS at different frequencies did not differ significantly. From baseline to the 1-month treatment period, the tONS group with 100 Hz and topiramate group exhibited significant decreases in headache duration. We conclude that tONS therapy is a new promising approach for migraine prevention. It has infrequent and mild adverse events and may be effective among patients who prefer nonpharmacological treatment.

Dexmedetomidine Added to Local Anesthetic Mixture of Lidocaine and Ropivacaine Enhances Onset and Prolongs Duration of a Popliteal Approach to Sciatic Nerve Blockade

Purpose

A literature review of multiple clinical studies on mixing additives to improve pharmacologic limitation of local anesthetics during peripheral nerve blockade revealed inconsistency in success rates and various adverse effects. Animal research on dexmedetomidine as an adjuvant on the other hand has promising results, with evidence of minimum unwanted results. This randomized, double-blinded, contrastable observational study examined the efficacy of adding dexmedetomidine to a mixture of lidocaine plus ropivacaine during popliteal sciatic nerve blockade (PSNB).

一种新的针刺促通技术：电针神经干治疗中风肢瘫

在偏瘫的现代康复医疗技术——促通技术的启发下,将传统针刺法改为电针神经干法治疗中风肢瘫62例,并与传统针刺法进行了疗效对比。Riddit分析结果显示:神经干组疗效明显优于传统组。作者根据国内外有关研究成果,对电针神经干的疗效原理展开了讨论。     

Efficiency of Neuromuscular Electrical Stimulation and Transcutaneous Nerve Stimulation on Hemiplegic Shoulder Pain: A Randomized Controlled Trial

Objective

To compare the efficacy of neuromuscular electrical stimulation (NMES) and transcutaneous nerve stimulation (TENS) on hemiplegic shoulder pain (HSP).