Botulinum toxin and short-term electrical stimulation in the treatment of equinus in cerebral palsy.

Intramuscular botulinum toxin type A (BT-A) has been shown to reduce spasticity and to improve gait in children with cerebral palsy. To determine whether the efficacy of BT-A may be enhanced by electrical stimulation, as suggested in focal dystonia or in adult spastic patients, 12 children with dynamic foot equinus deformity were randomly assigned to two groups in a blinded, clinically controlled trial. Intramuscular BT-A into calf muscles was followed by adjuvant electrical stimulation in Group A (n = 6) but not in Group B (n = 6). Clinical assessment and instrumented gait analysis were performed before and 1, 3, and 6 months after treatment. The combined treatment of BT-A and electrical stimulation was not superior to BT-A alone. For all patients, improvement of the clinical and gait variables occurred at 1 and 3 months after BT-A injection.     

A novel modulation strategy to increase stimulation duration in neuromuscular electrical stimulation

Introduction: Neuromuscular electrical stimulation (NMES) has been shown to be an effective treatment for muscular dysfunction. Yet, a fundamental barrier to NMES treatments is the rapid onset of muscle fatigue. The purpose of this study is to examine the effect of feedback‐based frequency modulation on the closed‐loop performance of the quadriceps during repeated dynamic contractions. Methods: In the first experiment, subjects completed four different frequency modulation NMES protocols utilizing the same amplitude modulation control to compare the successful run times (SRTs). A second experiment was performed to determine the change in muscle response to high‐ and low‐frequency stimulation. Results: Compared with constant‐frequency stimulation, results indicate that using an error‐driven strategy to vary the stimulation frequency during amplitude modulation increases the number of successful contractions during non‐isometric conditions. Conclusion: Simultaneous frequency and amplitude modulation increases the SRT during closed‐loop NMES control. Muscle Nerve 44: 382–387, 2011     

Functional electrical stimulation following nerve injury in a large animal model

Introduction: Controversy exists over the effects of functional electrical stimulation (FES) on reinnervation. We hypothesized that intramuscular FES would not delay reinnervation after recurrent laryngeal nerve (RLn) axonotmesis. Methods: RLn cryo-injury and electrode implantation in ipsilateral posterior cricoarytenoid muscle (PCA) were performed in horses. PCA was stimulated for 20 weeks in eight animals; seven served as controls. Reinnervation was monitored through muscle response to hypercapnia, electrical stimulation and exercise. Ultimately, muscle fiber type proportions and minimum fiber diameters, and RLn axon number and degree of myelination were determined. Results: Laryngeal function returned to normal in both groups within 22 weeks. FES improved muscle strength and geometry, and induced increased type I:II fiber proportion (p = 0.038) in the stimulated PCA. FES showed no deleterious effects on reinnervation. Discussion: Intramuscular electrical stimulation did not delay PCA reinnervation after axonotmesis. FES can represent a supportive treatment to promote laryngeal functional recovery after RLn injury. Muscle Nerve 59:717–725, 2019     

Neuromuscular electrical stimulation in neurorehabilitation

This review provides a comprehensive overview of the clinical uses of neuromuscular electrical stimulation (NMES) for functional and therapeutic applications in subjects with spinal cord injury or stroke. Functional applications refer to the use of NMES to activate paralyzed muscles in precise sequence and magnitude to directly accomplish functional tasks. In therapeutic applications, NMES may lead to a specific effect that enhances function, but does not directly provide function. The specific neuroprosthetic or "functional" applications reviewed in this article include upper- and lower-limb motor movement for self-care tasks and mobility, respectively, bladder function, and respiratory control. Specific therapeutic applications include motor relearning, reduction of hemiplegic shoulder pain, muscle strengthening, prevention of muscle atrophy, prophylaxis of deep venous thrombosis, improvement of tissue oxygenation and peripheral hemodynamic functioning, and cardiopulmonary conditioning. Perspectives on future developments and clinical applications of NMES are presented.     

电刺激联合重复经颅磁刺激对脑卒中患者偏侧忽略的影响

目的观察功能性电刺激联合重复经颅磁刺激(r TMS)对脑卒中患者偏侧忽略的影响。方法 40例脑卒中后偏侧忽略患者被随机分为观察组和对照组,每组各20例。2组患者均接受常规康复治疗和r TMS,观察组加以功能性电刺激治疗。采用行为忽略学测试(BIT)、凯瑟琳博格量表(CBS)、改良巴氏指数(MBI)及Fugl-Meyer上肢运动评定(FMA-UE)对治疗前后的偏侧忽略进行评定。结果治疗前,2组患者在年龄、性别、病程、卒中类型及MMSE评分比较,差异无统计学意义(P 0. 05)。治疗后,观察组在BIT(93. 7±6. 5)、CBS(13. 0±2. 6)、MBI(43. 5±4. 0)及FMA-UE(26. 6±5. 2)显著改善,差异有统计学意义(P 0. 05);对照组在BIT(80. 3±6. 9)、CBS(16. 1±3. 6)、MBI(37. 1±2. 4)及FMA-UE(18. 8±4. 1]改善,差异有统计学意义(P 0. 05)。观察组各项评分均优于对照组,差异有统计学意义(P 0. 05)。结论功能性电刺激联合r TMS能更有效改善脑卒中偏侧忽略,可作为偏侧忽略的联合治疗策略。     

Clinical Application of Peroneal Nerve Stimulator System Using Percutaneous Intramuscular Electrodes for Correction of Foot Drop in Hemiplegic Patients

Objective. To assess the orthotic effect of a functional electrical stimulation device (Akita Heel Sensor System; AHSS) in the treatment of hemiplegic gait with foot drop. Materials and Methods. In the AHSS, a heel sensor is attached to a small plastic heel brace, and the peroneal nerve is stimulated via percutaneous intramuscular electrodes. During the swing phase of the hemiplegic gait, the common peroneal nerve is stimulated by the AHSS. Eight patients in chronic stages of hemiplegia participated in this study. Walking speeds and step cadences on a 10‐m course were compared between walking with stimulation and walking without stimulation. Results. Mean walking speed (± SD) was 0.50 ± 0.26 m/sec without stimulation and 0.64 ± 0.31 m/sec with stimulation. The mean percentage increase in walking speed with stimulation was 30.1%. Mean step cadence was 31 ± 7 steps/10 m without stimulation and 27 ± 7 steps/10 m with stimulation. By correcting foot drop, the AHSS significantly increased walking speed and decreased cadence (p < 0.05). Conclusion. The AHSS can significantly improve walking in hemiplegic patients with foot drop.     

Interaction of electrical stimulation and voluntary hand movement in SII and the cerebellum during simulated therapeutic functional electrical stimulation in healthy adults

The therapeutic application of functional electrical stimulation (FES) has shown promising clinical results in the rehabilitation of post-stroke hemiplegia. It appears that the effect is optimal when the patterned electrical stimulation is used in close synchrony with voluntary movement, although the neural mechanisms that underlie the clinical successes reported with therapeutic FES are unknown. One possibility is that therapeutic FES takes advantage of the sensory consequences of an internal model. Here, we investigate fMRI cortical activity when FES is combined with voluntary effort (FESVOL) and we compare this activity to that produced when FES and voluntary activity (VOL) are performed alone. FESVOL revealed greater cerebellar activity compared with FES alone and reduced activity bilaterally in secondary somatosensory areas (SII) compared with VOL alone. Reduced activity was also observed for FESVOL compared with FES alone in the angular gyrus, middle frontal gyrus and inferior frontal gyrus. These findings indicate that during the VOL condition the cerebellum predicts the sensory consequences of the movement and this reduces the subsequent activation in SII. The decreased SII activity may reflect a better match between the internal model and the actual sensory feedback. The greater cerebellar activity coupled with reduced angular gyrus activity in FESVOL compared with FES suggests that the cortex may interpret sensory information during the FES condition as an error-like signal due to the lack of a voluntary component in the movement.     

功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床观察

目的 观察功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床疗效。方法 将53例缺血性脑卒中偏瘫患者随机分为对照组、治疗组、假治疗组3组,在均接受常规康复训练的基础上对照组接受功能性电刺激治疗,治疗组接受功能性电刺激及重复经颅磁刺激治疗,假治疗组接受功能性电刺激及假重复经颅磁刺激治疗; 治疗前及治疗8周后采用步态运动学参数、时间参数、距离参数及Amer-Lindholm分级对3组患者的下肢综合运动功能进行评定。结果 治疗前3组患者步态运动学参数、时间参数、距离参数及Amer-Lindholm分级评分均无显著差异(P>0.05),治疗8周后3组患者上述指标明显改善且治疗组改善幅度明显优于其余2组(P<0.05)。结论 功能性电刺激联合重复经颅磁刺激治疗有利于改善缺血性脑卒中偏瘫患者的步行运动功能。     

Transcranial electrical stimulation nomenclature

Transcranial electrical stimulation (tES) aims to alter brain function non-invasively by applying current to electrodes on the scalp. Decades of research and technological advancement are associated with a growing diversity of tES methods and the associated nomenclature for describing these methods. Whether intended to produce a specific response so the brain can be studied or lead to a more enduring change in behavior (e.g. for treatment), the motivations for using tES have themselves influenced the evolution of nomenclature, leading to some scientific, clinical, and public confusion. This ambiguity arises from (i) the infinite parameter space available in designing tES methods of application and (ii) varied naming conventions based upon the intended effects and/or methods of application. Here, we compile a cohesive nomenclature for contemporary tES technologies that respects existing and historical norms, while incorporating insight and classifications based on state-of-the-art findings. We consolidate and clarify existing terminology conventions, but do not aim to create new nomenclature. The presented nomenclature aims to balance adopting broad definitions that encourage flexibility and innovation in research approaches, against classification specificity that minimizes ambiguity about protocols but can hinder progress. Constructive research around tES classification, such as transcranial direct current stimulation (tDCS), should allow some variations in protocol but also distinguish from approaches that bear so little resemblance that their safety and efficacy should not be compared directly. The proposed framework includes terms in contemporary use across peer-reviewed publications, including relatively new nomenclature introduced in the past decade, such as transcranial alternating current stimulation (tACS) and transcranial pulsed current stimulation (tPCS), as well as terms with long historical use such as electroconvulsive therapy (ECT). We also define commonly used terms-of-the-trade including electrode, lead, anode, and cathode, whose prior use, in varied contexts, can also be a source of confusion. This comprehensive clarification of nomenclature and associated preliminary proposals for standardized terminology can support the development of consensus on efficacy, safety, and regulatory standards.     

An Investigation of the Effect of Modifying Stimulation Profile Shape on the Loading Response Phase of Gait,during FES‐Corrected Drop Foot: Stimulation Profile and Loading Response

Drop foot stimulators today operate open loop with a trapezoidal stimulation profile. The traditionally applied profile originated as much from technological constraints as suitability for the physical pathology. It was proposed that by increasing the stimulation intensity during the loading response phase of gait, the ankle angle trajectory would become closer to that of normal gait and a more efficient heel rocker would be introduced. One patient, who used an implanted stimulator, was tested. Various profiles, which provided increased stimulation during loading response, were tried and joint angle trajectories, electromyograms, and footswitches were recorded. Statistical analysis was performed using a one way anova and posthoc Tukey tests. The experiment showed that increasing stimulation intensity during loading response increased the duration of the heel rocker. Statistical analysis revealed that this was significant at p = 0.05 level. Increasing stimulation intensity during loading response prolongs the heel rocker. This is an essential mechanism for advancement over the stance limb and providing shock absorption during weight acceptance, thus, we conclude that this improves the gait pattern of the drop foot sufferer.     

Effects of electrical stimulation pattern on quadriceps force production and fatigue

Introduction: Mixed stimulation programs (MIX) that switch from constant frequency trains (CFT) to variable frequency trains have been proposed to offset the rapid fatigue induced by CFT during electrical stimulation. However, this has never been confirmed with long stimulation patterns, such as those used to evoke functional contractions. The purpose of this study was to test the hypothesis that MIX programs were less fatiguing than CFTs in strength training‐like conditions (6‐s contractions, 30‐min). Methods: Thirteen healthy subjects underwent 2 sessions corresponding to MIX and CFT programs. Measurements included maximal voluntary isometric torque and torque evoked by each contraction. Results: There were greater decreases of voluntary and evoked torque (P < 0.05) after CFT than MIX, and mean torque was 13 ± 1% higher during the MIX session (P < 0.05). Conclusions: These findings confirm that combining train types might be a useful strategy to offset rapid fatigue during electrical stimulation sessions with long‐duration contractions. Muscle Nerve 49 : 760–763, 2014     

Distributed low‐frequency functional electrical stimulation delays muscle fatigue compared to conventional stimulation

We present a low‐frequency stimulation method via multi‐pad electrodes for delaying muscle fatigue. We compared two protocols for muscle activation of the quadriceps in paraplegics. One protocol involved a large cathode at 30 HZ (HPR, high pulse‐rate), and the other involved four smaller cathodes at 16 HZ (LPR, low pulse‐rate). The treatment included 30‐min daily sessions for 20 days. One leg was treated with the HPR protocol and the other with the LPR protocol. Knee‐joint torque was measured before and after therapy to assess the time interval before the knee‐joint torque decreased to 70% of the initial value. The HPR therapy provided greater increases in muscle endurance and force in prolonged training. Yet the LPR stimulation produced less muscle fatigue compared to the HPR stimulation. The results suggest that HPR is the favored protocol for training, and LPR is better suited for prolonged stimulation. Muscle Nerve, 2010     

Changes in neuromuscular function after training by functional electrical stimulation

We examined whether the neuromuscular function of rectus femoris (RF) and flexor digitorum brevis (FDB) in humans was modified after a 6-week training period of functional electrical stimulation (FES), and whether any effects persisted at the end of a 6-week post-FES recovery period. In both the stimulated and contralateral nonstimulated muscles, we recorded the muscle force, surface electromyogram, and M wave, and also measured the root mean square (RMS) and the median frequency (MF) during static contraction sustained until exhaustion at 60% of maximal voluntary contraction (MVC). FES was performed with symmetric biphasic pulses, with a ramp modulation of both the stimulation frequency and pulse duration. No changes in MCV and endurance time to exhaustion occurred in nonstimulated muscles, whereas a significant MVC increase occurred immediately after FES in RF (+14 +/- 5%) and FDB (+13 +/- 5%), these effects persisting 6 weeks after the end of FES. In FDB, FES also elicited a significant increase in endurance time to exhaustion (+18 +/- 7%). The M-wave characteristics never varied after FES, but a marked attenuation occurred in the MF decrease and the RMS increase measured at endurance time to sustained 60% MVC, especially in FDB, which contains the higher proportion of type II fibers. These data indicate that FES improves muscle function and elicits changes in central muscle activation. The benefits of FES were greater in FDB, which is highly fatigable, and persisted for at least a 6-week period.     

Enhancement of Isometric Ankle Dorsiflexion by Automyoelectrically Controlled Functional Electrical Stimulation on Subjects with Upper Motor Neuron Lesions

The objective of this study was to test myoelectrically controlled functional electrical stimulation of the same muscle (AutoMCS) on patients with either stroke or spinal cord injury. The paretic anterior tibialis (TA) muscle was stimulated with an amplitude controlled continuously by the volitional myoelectric signal from the same muscle. Surface electrodes were used and volitional myoelectric signals were extracted by analog/digital signal processing techniques. Isometric dorsiflexion torque of the foot was displayed on a screen and the subjects were asked to track a sinusoidal curve. Subjects with dropped foot, as a result of a stroke (CVA, n = 9) or spinal cord lesion (SCI, n = 4), performed tests without and then with AutoMCS applied to the muscle. Subjects were their own control and tracking tests without and with AutoMCS. Changes in torque range, tracking delay, and tracking control accuracy have been evaluated. A significant (p < 0.05) increase of dorsiflexion torque by AutoMCS was found. An immediate carryover effect was seen in one stroke subject. The analysis of the tracking control showed only little loss of controllability with the system. We conclude that for selected subjects this method can instantly increase the muscle force of the anterior tibialis without significantly compromising tracking control or tracking delay.     

电刺激疗法治疗脑卒中后吞咽障碍的疗效研究

目的探讨电刺激疗法治疗脑卒中所致吞咽障碍的临床疗效。方法75例脑卒中后吞咽障碍患者分为电刺激组,针灸组及康复训练组各25例,前两组在接受常规药物治疗及康复训练基础上分别加用电刺激治疗和针灸。三组治疗前、治疗第1周及第2周以吞咽障碍程度分级评分评定疗效。结果三组治疗后吞咽障碍程度分级评分均明显高于治疗前（P〈0.01）;电刺激组评分明显高于针灸组和康复训练组（P〈0.01）;电刺激组治疗第1、第2周后有效率明显高于针灸组和康复训练组（P〈0.05）。结论电刺激疗法可明显改善脑卒中所致吞咽障碍,配合针灸,康复训练等综合疗法可加强治疗效果。     

Apraxia of lid opening is alleviated by pallidal stimulation in a patient with Parkinson's disease

Apraxia of lid opening (ALO) is a syndrome characterized by a non-paralytic inability to open the eyes at will in the absence of visible contraction of the orbicularis oculi muscle. Here we report that globus pallidus internus deep brain stimulation on the right side markedly alleviates ALO as well as gait freezing in a patient with Parkinson's disease.     

Brain stimulation: a therapeutic approach for the treatment of neurological disorders

Brain stimulation has become one of the most acceptable therapeutic approaches in recent years and a powerful tool in the remedy against neurological diseases. Brain stimulation is achieved through the application of electric currents using non-invasive as well as invasive techniques. Recent technological advancements have evolved into the development of precise devices with capacity to produce well-controlled and effective brain stimulation. Currently, most used non-invasive techniques are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), whereas the most common invasive technique is deep brain stimulation (DBS). In last decade, application of these brain stimulation techniques has not only exploded but also expanded to wide variety of neurological disorders. Therefore, in the current review, we will provide an overview of the potential of both non-invasive (rTMS and tDCS) and invasive (DBS) brain stimulation techniques in the treatment of such brain diseases.     

Rebuilding motor function of the spinal cord based on functional electrical stimulation

Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the correspond-ing muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip lfexion, ankle plantarlfexion, and ankle dorsilfexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury.