Functional neuromuscular stimulation in spinal cord injury

With recent advances in clinical medicine and biomedical engineering, functional neuromuscular stimulation (FNS) can now be added to the psychiatric armamentarium to decrease the debilitating effects of traumatic spinal cord injury. In this article, the components of FNS systems and their evolution in design are presented. The clinical implications of FNS are discussed with respect to upper and lower extremities and bladder applications, and perspectives on future developments and directions are reviewed.     

Functional neuromuscular stimulation for standing after spinal cord injury

A study was undertaken to determine if functional neuromuscular stimulation could be used to obtain standing in patients with traumatic spinal cord injury. Twenty-five subjects were selected during the study, and standing was accomplished in 21 using bilateral quadriceps stimulation with the hips in hyperextension. Four subjects elected not to continue participation to the point of standing. Stimulation parameters were 0 to 120V pulse amplitude, frequency 13Hz or 20Hz, and pulse width of 0.4msec. Confirmation of standing with support of 95% of the body weight by the legs was verified by quantitative measurements with a dual-scale force platform or a biomechanics force platform. Subjects initially selected had injury levels between C7 and T11 and ranged in age from 22 to 47 years, with duration of injury from one to 13 years. The subjects had complete lesions, with no active motor function below the last normal level, and absent sensation or partial sparing of sensation with vague perception of pinprick, but no position sense. Six subjects stood at home and 15 stood only in the laboratory. This five-year experience indicates that paraplegic individuals may obtain standing with functional neuromuscular stimulation.     

Functional magnetic stimulation for conditioning of expiratory muscles in patients with spinal cord injury

OBJECTIVE: To evaluate the effectiveness of functional magnetic stimulation (FMS) in conditioning expiratory muscles patients with spinal cord injury (SCI). DESIGN: A prospective before-after trial. SETTING: The Functional Magnetic Stimulation Laboratory of the SCI Health Care Group, VA Long Beach Health Care System, and the Spinal Cord Injury Services, Department of Veterans Affairs, Palo Alto Health Care System. PARTICIPANTS: Eight men with tetraplegia. INTERVENTION: Expiratory muscle training was achieved by placing a magnetic stimulator with a round magnetic coil along subjects' lower thoracic spine. MAIN OUTCOME MEASURES: Measures taken were the maximal expired pressure at total lung capacity (MEP-TLC) and at functional residual capacity (MEP-FRC), expiratory reserve volume (ERV), and the forced expiratory flow rate at TLC (FEF-TLC) and at FRC (FEF-FRC) by subjects' voluntary maximal efforts. RESULTS: After 4 weeks of conditioning, the mean +/- standard error of the mean values were: MEP-TLC, 55.3 +/- 8.6cmH(2)O; MEP-FRC, 29.6 +/- 5.6cmH(2)O; ERV,.57 +/-.08L; FEF-TLC, 4.3 +/- 0.5L/s; and FEF-FRC, 1.9 +/- 0.2L/s. These values correspond to, respectively, 129%, 137%, 162%, 109%, and 127% of pre-FMS conditioning values. When FMS was discontinued for 2 weeks, the MEP-TLC returned to its pre-FMS training value. CONCLUSION: A 4-week protocol of FMS of the expiratory muscles improves voluntary expiratory muscle strength significantly, indicating that FMS can be a noninvasive therapeutic technology in respiratory muscle training for persons with tetraplegia.     

功能性磁刺激治疗脊髓损伤患者神经源性膀胱

目的：观察功能性磁刺激(FMS)治疗脊髓损伤患者神经源性膀胱的疗效。方法：采用经S3神经根和膀胱区的FMS治疗脊髓损伤后神经源性膀胱患者12例，通过对患者尿流动力学的检查、因排尿症状而影响生活质量的生活质量评分和国际下尿路综合征(LUTS)症状评分进行疗效评价。结果：10例患者症状有显著改善，日平均排尿次数显著减少，日平均单次尿量增加，尿频、尿急、尿失禁的程度减轻，2例患者无效。结论：FMS可以显著地改善部分脊髓损伤后神经源性膀胱患者的膀胱功能并能显著提高患者的生活质量。     

Functional electric stimulation-assisted rowing: Increasing cardiovascular fitness through functional electric stimulation rowing training in persons with spinal cord injury

OBJECTIVES: To assess changes in peak functional aerobic power after a 36-session, progressive functional electric stimulation (FES) rowing hybrid training program for persons with spinal cord injury (SCI) and to examine the safety and acceptability of the ROWSTIM II device as well as the integrity of technical modifications to it. DESIGN: Repeated-measures training study, quasi-experimental design, within-person data comparison. SETTING: A university-based recreational physical activity facility for persons with physical disabilities. PARTICIPANTS: Six persons with level C7-T12 SCI (American Spinal Injury Association classes A-C). INTERVENTION: Progressive rowing training program, 30 minutes per session, 3 times a week for 12 weeks at 70% to 75% of pretest peak functional aerobic power during FES rowing on an open loop control, FES-assisted rowing machine. MAIN OUTCOME MEASURES: Total rowing distance, peak functional oxygen consumption, and peak oxygen pulse. RESULTS: Subjects completed between 22 to 36 sessions. After 3 months of training, rowing distance increased by 25% (P<.02), peak oxygen consumption by 11.2% (P<.001), and peak oxygen pulse by 11.4% (P<.01). Heart rate response to hybrid training did not change at the end of training, although peak heart rate with FES lower-extremity exercise increased significantly from pre- to posttraining (P<.01). CONCLUSIONS: Pre- and posttraining peak aerobic power values for ROWSTIM II training were comparable to previously reported values for hybrid cycle and upper-extremity exercise. We conclude that FES-assisted rowing is an effective, safe, and well-tolerated training system for persons with SCI.     

Functional electric stimulation to augment partial weight-bearing supported treadmill training for patients with acute incomplete spinal cord injury: A pilot study

OBJECTIVE: To study the application of partial weight-bearing (PWB) supported treadmill gait training augmented by functional electric stimulation (FES) in subjects with acute incomplete spinal cord injury (SCI). DESIGN: Before-after crossover trial with control (A) and intervention (B) periods. SETTING: Physiotherapy (PT) department of a spinal injuries unit in Scotland. PARTICIPANTS: Fourteen inpatients with acute incomplete SCI with American Spinal Injury Association class C or D injury. INTERVENTION: Training consisted of treadmill walking with PWB support augmented by FES. Subjects walked on the treadmill for up to 25 minutes a day, 5 days a week for 4 weeks. The intervention was compared with a 4-week control period in which standard PT was given. MAIN OUTCOME MEASURES: Overground walking endurance and speed, cadence, stride length, and observational gait analysis and walking speed, distance, and percentage PWB support on the treadmill. RESULTS: A greater increase in overground walking endurance was achieved after the intervention (AB group mean, 72.2m; confidence interval [CI], 39.8-104.6m; BA group mean, 63.8m; CI, -10.2 to 137.9m), as compared with after standard PT (AB group mean, 38.4m; CI, 1.8-75.0m; BA group mean, 60.1m; CI, 9.2-110.9m). A similar pattern was observed for overground walking speed. CONCLUSIONS: This pilot study indicated that PWB supported treadmill training with FES had a positive effect on overground gait parameters and could potentially accelerate gait training in subjects with incomplete SCI. A larger randomized trial is required to substantiate these findings.     

An electric stimulation cycling protocol for gait in incomplete spinal cord injury

OBJECTIVE: To determine the feasibility and impact of an outpatient, electric stimulation cycling (ESC) protocol on a patient with incomplete spinal cord injury (SCI). DESIGN: Pre-post case study. SETTING: Outpatient rehabilitation hospital. PARTICIPANT: A 24-year old man with an incomplete SCI occurring 25 months before study entry at the T12-L1 level. INTERVENTION: A 2-phase, 10-week ESC intervention occurring 3 days a week. Phase 1 provided 30-minute ESC sessions at increasing resistance with electric stimulation applied to the quadriceps and hamstrings; phase 2 required cycling independently (ie, without stimulation) at maximal effort for increasing lengths of time. MAIN OUTCOME MEASURES: Gait velocity, stride length, and step length, all collected during a 10-meter walking test, and the Walking Index of Spinal Cord Injury-II (WISCI-II). RESULTS: During phase 1, the patient quickly increased workload, session duration, and distance; during phase 2, duration that the subject was able to cycle without stimulation increased markedly. After the entire intervention, the subject exhibited diminished edema, new ability to voluntarily step, new ability to voluntarily dorsiflex the ankle and voluntarily flex the toe, and new ability to perform valued activities, such as transfers. He also exhibited increased mean gait velocity (.33 m/s), left (.11 m) and right (.07 m) stride length, left (.06 m) and right (.05 m) step length, and a 10-point WISCI-II increase. The subject was also able to discontinue use of several medications after intervention. CONCLUSIONS: SCI patients' endurance and gait deficits can possibly be effectively addressed on an outpatient basis and with minimal assistance by using this regimen.     

Functional paralysis mimicking spinal cord injury resulting in admission to a spinal cord injury center

From 1978 through 1982, five patients with final diagnoses of nonorganic functional paraplegia or quadriplegia were seen and treated at the Northern California Regional Spinal Cord Injury Center. The patients ranged in age from 13 to 26 years and four were males. All had normal bowel and bladder function with otherwise complete motor and sensory paralysis, shifting sensory findings, and normal deep tendon reflexes early after injury. In each patient, a retrospective analysis demonstrated that structural anatomic lesion could be ruled out by a neurologic examination. Clinical and investigatory studies are discussed with respect to the diagnostic process.     

Functional electrical stimulation effect on orthostatic hypotension after spinal cord injury

OBJECTIVE: To investigate the possibility of using functional electrical stimulation (FES) to control orthostatic hypotension in patients with spinal cord injury (SCI) and to clarify the mechanism of the response. DESIGN: Subjects were tilted by 10 degree increments with varying intensities of lower-extremity FES. Stimulation over muscles was compared to stimulation over noncontractile sites. SETTING: Physical therapy department of a major rehabilitation center. PATIENTS: Six patients with SCI above T6 (3 with recent injury recruited consecutively from an inpatient spinal cord rehabilitation unit, and 3 from the community with longstanding injury, recruited as volunteers). MAIN OUTCOME MEASURES: Blood pressure, heart rate, and perceived presyncope score recorded at each tilt angle and analyzed using a multivariate analysis of variance statistical methodology. RESULTS: Systolic and diastolic blood pressure increased with increasing stimulation intensities (systolic, p = .001; diastolic, p = .0019) and decreased with increasing angle of tilt (p < .001) regardless of the site of stimulation. Subjects tolerated higher angles of incline with electrical stimulation than without (p = .03). CONCLUSIONS: FES causes a dose-dependent increase in blood pressure independent of stimulation site that may be useful in treating orthostatic hypotension.     

Functional magnetic stimulation of the colon in persons with spinal cord injury

OBJECTIVE: To evaluate the usefulness of functional magnetic stimulation (FMS) as a noninvasive method to stimulate the colon in individuals with spinal cord injury (SCI). DESIGN: A prospective before-after trial consisting of 2 protocols. SETTING: FMS laboratories of 2 SCI centers. PARTICIPANTS: Two able-bodied men and 13 men with SCI levels ranging from C3 to L1. Protocol 1 consisted of 9 subjects, 2 of whom were excluded from the analysis. Protocol 2 consisted of 4 subjects. INTERVENTION: Commercially available magnetic stimulators with round magnetic coils (MCs) were used. Protocol 1 measured the effects of FMS on rectal pressure by placing the MC on the transabdominal and lumbosacral regions. Protocol 2 consisted of a 5-week stimulation period to investigate the effects of FMS on total and segmental colonic transit times (CTTs). MAIN OUTCOME MEASURE: An increase in rectal pressure and a decrease in CTT by magnetic stimulation. RESULTS: Data were averaged and the standard error of the mean was calculated. Statistically significant changes in rectal pressure and CTT were also measured. Rectal pressures increased from 26.7 +/- 7.44cmH(2)O to 48.0 +/- 9.91cmH(2)O, p =.0037, with lumbosacral stimulation, and from 30.0 +/- 6.35cmH(2)O to 42.7 +/- 7.95cmH(2)O, p =.0015, with transabdominal stimulation. With FMS, the mean CTT decreased from 105.2 to 89.4 hours, p =.02. CONCLUSION: FMS is able to stimulate the colon and reduce CTT. FMS is a noninvasive, technological advancement for managing neurogenic bowel in patients with SCI.     

经皮电神经刺激配合磁热振疗法对脊髓损伤中枢性疼痛的疗效观察

目的:探讨经皮电神经刺激（TENS）合并磁热振治疗对脊髓损伤（SCI）中枢性疼痛的效果。方法：将36例SCI后中枢性疼痛患者随机分为观察组(A组)、TENS组（B组）、磁热振治疗组（C组）,每组12例。观察组采用经皮电神经刺激疗法合并磁热振治疗,TENS组只采用经皮电神经刺激疗法,磁热组只采用磁热振疗法。三组均在治疗前、治疗后采用简式McGill疼痛问卷对中枢性疼痛进行评定。结果：疗程结束后,患者疼痛的6项参数值均有降低,TENS组参数值低于磁热组,但两组差异并无显著性;观察组参数值显著低于TENS组或磁热振组（P<0.01）。结论：经皮电神经刺激合并磁热振疗法对治疗SCI后中枢性疼痛优于单纯的经皮电神经刺激疗法和磁热振疗法。     

Comparison of electric stimulation methods for reduction of triceps surae spasticity in spinal cord injury

OBJECTIVES: To compare the effect of 3 methods of electric stimulation to reduce spasticity of the triceps surae in patients with complete spinal cord injury (SCI) and to investigate the carryover effect. DESIGN: Placebo-controlled study with repeated measurements after the interventions. SETTING: Research department affiliated with a rehabilitation hospital in the Netherlands. PARTICIPANTS: Ten patients with a complete SCI were recruited from the outpatient population of the rehabilitation hospital. All subjects had American Spinal Injury Association grade A impairment scores, except for one, who had grade C. The patients had no voluntary triceps surae contractibility. INTERVENTIONS: Forty-five minutes of cyclic electric stimulation of the agonist, antagonist, or dermatome of the triceps surae or a placebo approach. MAIN OUTCOME MEASURES: Outcome measures were the Modified Ashworth Scale (MAS), clonus score, and the H-reflex and M wave (H/M) ratio. The electromyographic response to a stretch of the soleus over the whole range of motion was also determined. The magnitude and ankle angle at which the electromyographic response started were calculated. RESULTS: Stimulation of the agonist provided a significant reduction in the MAS compared with the placebo approach (P<.001). There was no significant change in the H/M ratio or the electromyographic response amplitude after any of the stimulation methods, whereas stimulation of the antagonist muscle resulted in a significant reduction in the ankle angle at which the electromyographic response started, compared with the placebo approach (P<.037). CONCLUSIONS: Triceps surae stimulation reduces the MAS for that specific muscle, whereas the angle at which the reflex starts changes after antagonist stimulation.     

Circulatory hypokinesis and functional electric stimulation during standing in persons with spinal cord injury.

OBJECTIVE: To evaluate the effects of functional electric stimulation (FES) of lower limb muscles during 30 minutes of upright standing on the central and peripheral hemodynamic response in persons with spinal cord injury (SCI). DESIGN: A repeated-measure design. Subjects were used as their own control and underwent 2 testing protocols of FES-augmented standing (active standing) and non-FES standing (passive standing). SETTING: Rehabilitation hospital. PARTICIPANTS: Fourteen individuals with SCI (7 with tetraplegia, 7 with paraplegia). INTERVENTIONS: During active standing, FES was administered to 4 muscle groups of each leg in an overlapping fashion to produce a pumping mechanism during standing. During passive standing, subjects stood for 30 minutes using a standing frame with no FES intervention. MAIN OUTCOME MEASURES: Central hemodynamic responses of stroke volume, cardiac output, heart rate, arterial blood pressure, total peripheral resistance (TPR), and rate pressure product (RPP) were evaluated by impedance cardiography. All measurements were performed during supine and sitting positions before and after standing, and during 30 minutes of upright standing. RESULTS: Comparisons between the groups with paraplegia and tetraplegia showed a significant increase in heart rate in the paraplegics after 30 minutes of active standing. During active standing, paraplegics' heart rate increased by 18.2% (p = .015); during passive standing, it increased by 6% (p = .041). TPR in the tetraplegics significantly (p = .003) increased by 54% when compared with the paraplegics during passive standing. Overall, the tetraplegic group had a significantly lower systolic blood pressure (p = .013) and mean arterial pressure (p = .048) than the paraplegics during passive standing. These differences were not detected during active standing. When data were pooled from both groups and the overall groups response to active and passive standing were compared, the results showed that cardiac output, stroke volume, and blood pressure significantly decreased (p < .05) during 30 minutes of passive standing, whereas TPR significantly increased (p < .05). All of the hemodynamic variables were maintained during 30 minutes of active standing, and there were increases in RPP and heart rate after 30 minutes of active standing. CONCLUSION: FES of the lower extremity could be used by persons with SCI as an adjunct during standing to prevent orthostatic hypotension and circulatory hypokinesis. This effect may be more beneficial to those with tetraplegia who have a compromised autonomic nervous system and may not be able to adjust their hemodynamics to the change in position.     

Functional improvement after pediatric spinal cord injury

OBJECTIVE: To describe the functional gain (FGain) with pediatric spinal cord injury inpatient rehabilitation and to identify the relationship of various factors to FGain in pediatric spinal cord injury inpatient rehabilitation. DESIGN: Retrospective chart review of a series of 91 children with spinal cord injury admitted from 1993 to 1998 in a freestanding rehabilitation hospital. Admission and discharge functional status were assessed with the Pediatric Functional Independence Measure (WeeFIM) instrument for children 7 yr. The outcome measure is the FGain (difference between the discharge and admission functional status). RESULTS: Significant gains in functional status were observed in all patients. FGain was not significantly related to age, sex, length of inpatient rehabilitation, pathogenesis, or completeness or neurologic level of injury. However, there was a trend for higher FGain for patients with incomplete spinal cord injury and traumatic spinal cord injury. CONCLUSIONS: Functional improvement occurs with pediatric spinal cord injury inpatient rehabilitation. There is a trend for higher FGain in patients with less severe injury and traumatic injury. The lack of relationship between FGain and length of inpatient rehabilitation suggests that a variety of other factors influence the relationship between FGain and length of inpatient rehabilitation.     

Abdominal electric stimulation facilitates penile vibratory stimulation for ejaculation after spinal cord injury: a single-subject trial

OBJECTIVE: To compare the success rate of penile vibratory stimulation (PVS) alone with PVS and abdominal electric stimulation (AES). DESIGN: Single-subject trials. SETTING: Outpatient. PARTICIPANT: Man with chronic T3 complete (American Spinal Injury Association Impairment Scale grade A) spinal cord injury. Spasticity, Babinski response, anal wink, and bulbocavernosus reflexes were all present. INTERVENTION: Stimulation was presented to the frenulum using a Ferti Care Personal vibrator set at maximal settings (frequency, 110 Hz; amplitude, 3.55 mm). AES was applied to the abdomen using a commercially available muscle stimulator at maximal stimulus intensity and duration settings. Trials were randomized to PVS only or PVS plus AES. MAIN OUTCOME MEASURES: Presence or absence of ejaculation, and time to ejaculation. RESULTS: Only 4 of 30 trials were positive with PVS alone, while 31 of 34 trials were positive with PVS plus AES. Additionally, 17 of 26 PVS trials, which were initially negative with PVS alone, were then positive with the addition of AES. This represents a clinically relevant improvement with use of AES. Time to ejaculation for positive trials with either technique was not statistically significant. CONCLUSIONS: AES significantly lowered the threshold for ejaculation elicited with vibratory stimulation and increased the success rate over that when PVS alone was used.     

Secondary spinal lesions in spinal cord injury patients

On hospital admission, 6 spinal cord injured patients were noted to have second noncontiguous levels of spinal injury that were previously unrecognized. These secondary levels of spinal injury were diagnosed as a result of routine admission total spine radiographic examinations. Two cases are described in detail, one with the secondary spinal lesion above and the other below the primary spinal cord injury. Careful total spine radiographic studies are recommended to prevent complications, in the event that such lesions are initially unrecognized.     

膀胱电刺激对促进脊髓损伤后膀胱功能重建作用的探讨

[目的]探讨脊髓损伤后膀胱电刺激对促进膀胱功能重建的作用。[方法]将100例颈、胸、腰段外伤性脊髓损伤尿潴留病人随机分为两组,每组50例。治疗组经知情同意后应用膀胱电刺激结合常规膀胱功能训练,进行膀胱电刺激时根据病人情况选择最佳参数、频率及电流强度。对照组给予常规膀胱功能训练。[结果]治疗组尿管留置时间明显缩短,完全性排尿增多,尿路感染率明显降低。[结论]膀胱电刺激能有效地改善骶段以上脊髓损伤病人尿潴留,可促进脊髓损伤后病人生理排尿模式的重建,减少尿路感染。     

Functional changes in persons aging with spinal cord injury

Declines in general physical function and the effect of these changes on activities of daily living and needs for assistance were assessed in 150 individuals with spinal cord injury (SCI). The sample consisted of outpatients returning for follow-up at the spinal cord injury clinic at Rancho Los Amigos National Rehabilitation Center in Downey, CA. The average duration of injury of the sample was 13 years (range 1-37), and average age was 38 years (range 18-64). Twenty-four percent of those sampled experienced a decline or change in their physical function within the last 5 years. Individuals experiencing declines were significantly older than those without changes, averaging 45 years versus 36 years. The group with change also had a longer duration of injury, averaging 18 years versus 11 years compared to the group reporting no declines. Fatigue was the most frequently reported problem, followed by pain and weakness. Over half of the group with changes required additional assistance with activities of daily living (ADLs). Family members were the primary helpers for both ADLs and instrumental activities of daily living (IADLs) for those persons experiencing changes. The use of assistive technology, primarily equipment for bathing, toileting, and low technology devices, increased with time. The increased vulnerability to loss of function in persons with advancing age and duration of injury in this population with SCI suggests the need for early preventative measures, routine assessments to detect changes, and access to health care and supportive services to alleviate or minimize the effect of these changes.     

电针刺激脊髓损伤患者穴位的脊髓磁共振功能成像激活区特征

背景:研究发现脊髓功能激活区域和电生理等理论对应区域相一致,多数学者认为使用功能磁共振技术检测脊髓神经功能是可行的.目的:检测电针刺激脊髓损伤患者的脊髓磁共振功能成像激活区特征,验证使用脊髓磁共振功能成像技术来客观评价针灸治疗脊髓损伤疗效的可行性.方法;使用电针同时刺激3例脊髓损伤患者和5名健康志愿者的右手合谷穴和曲池穴,采用组块设计方法,使用SPM2软件得到患者和健康志愿者脊髓内真实的激活区,分析激活区在矢状位和横断位上的分布特征,并与健康志愿者的激活分布对比,找出患者的激活分布差异.结果与结论:5名健康志愿者在脊柱C2、C5段均重复出现激活信号,在C6段4名出现激活;3例脊髓损伤患者在脊柱C2,C6段均出现均重复出现激活,其中1例患者与健康志愿者激活分布特征基本一致.可以观察到针灸刺激脊髓损伤患者的脊髓功能激活,因此可以根据功能激活区的分布及强度,在一定程度上客观评价针灸治疗脊髓损伤的疗效.     

脊髓损伤后的排尿功能重建

目的 :介绍2种恢复脊髓损伤 (SCI)后控制性排尿的新方法及其临床经验。方法 :(1)总结国内第1例Brindley 骶神经前根电刺激器埋置术的手术方法和经验。(2)在成功建立犬膝腱 -脊髓 -膀胱人工反射弧的基础上 ,对3例圆锥上SCI痉挛性膀胱的病人 ,进行肌腱 -脊髓 -膀胱人工反射弧建立术。结果 :安装Brindley电刺激器的病人 ,术后随访6个月 ,控制性排尿良好 ,尿失禁被完全根除。建立人工膀胱反射弧的3例病人 ,1例随访13个月 ,已能通过人工反射弧激发排尿 ,效果良好。结论 :骶神经前根电刺激和建立人工膀胱反射弧是恢复SCI病人控制性排尿功能的可靠方法。