Home use of a functional electrical stimulation system for standing and mobility in adolescents with spinal cord injury

OBJECTIVE: Functional electrical stimulation (FES) is a technology that may allow some patients with spinal cord injury (SCI) to integrate standing and upright mobility with wheelchair mobility. The purpose of this study was to document the patterns of home and community use of a FES system for standing and mobility. DESIGN: A telephone questionnaire was administered every 1 to 4 weeks for a minimum of 1 year. An interview was given at the end of the study to probe the motivators and barriers to home use. SETTING: Training for use of the FES system was performed in an inpatient pediatric rehabilitation setting. Data collection began after the subjects were discharged to home. PARTICIPANTS: Five adolescents with complete, thoracic-level SCI. INTERVENTION: Subjects participated in a program of FES exercise followed by training in basic mobility skills such as standing transfers, maneuvering, level ambulation, one-handed and reaching activities, and stair ascent/descent. MAIN OUTCOME MEASURE: The frequency with which the FES system was used at home and the activities for which it was utilized were documented. Motivators and barriers to FES home use were examined. RESULTS: Subjects donned the FES system on the average once every 3 to 4 days. Between 51% and 84% of the times donned, the system was used for exercise. The remaining times it was used for standing activities, most commonly reaching, one-handed tasks, and standing for exercise. "Motivators" included being able to do things that would otherwise be difficult, perceiving a healthful benefit or a sense of well-being from standing and exercise, and feeling an obligation to stand as a participant in a research study. "Barriers" to FES use included not finding time to use the system, having difficulty seeing opportunities to stand, and being reluctant to wear the FES system all day.     

Effects of functional electrical stimulation on the joints of adolescents with spinal cord injury

Nineteen adolescent subjects with complete spinal cord injuries resulting in paraplegia or tetraplegia participated in a functional electrical stimulation (FES) program consisting of computerized, controlled exercise and/or weight bearing. The effects of stimulated exercise and standing/walking on the lower extremity joints were prospectively studied. Plain radiographs and MRIs were obtained prior to and following completion of the exercise and standing and walking stages. In addition, the joints of five subjects were studied with synovial biopsies, arthroscopy, and the analysis of serum and synovial fluid for a 550 000 dalton cartilage matrix glycoprotein (CMGP). Pre-exercise joint abnormalities secondary to the spinal cord injury improved following the stimulation program. None of the subjects developed Charcot joint changes. Upon standing with FES, one subject with poor hip coverage prior to participation developed hip subluxation which required surgical repair. No other detrimental clinical effects occurred in the lower extremity joints of subjects participating in an FES program over a 1-year period.     

Gas exchange kinetics during functional electrical stimulation in subjects with spinal cord injury

We examined the kinetics of VO2, VCO2, and VE following the onset of unloaded leg cycling, and in recovery, in six patients with spinal cord injury (SCI). Exercise was produced by functional electrical stimulation (FES) of the quadriceps, hamstrings, and gluteal muscles. End-exercise VO2 (1.03 +/- 0.16 l.min-1), VCO2 (1.20 +/- 0.22 l.min-1) and VE (41 +/- 10 l.min-1) were elevated compared to values typically seen in healthy ambulatory subjects performing similar unloaded cycling. Mean response times for the on transients (MRTon) were both long and variable across subjects for VO2 (165 +/- 62 s), VCO2 (173 +/- 58 s), and VE (202 +/- 61 s). Recovery kinetics showed much less intersubject variability, and for five of six subjects were faster than the equivalent exercise MRT for all three variables (MRToff for VO2 of 103 +/- 28 s, VCO2 136 +/- 20 s, and VE 144 +/- 34 s), but P > 0.05 for all three. Size of the O2 deficit (1.96 +/- 0.90 l) and end-exercise lactate (7.05 +/- 1.65 mmol.l-1) were similar to values reported for healthy sedentary subjects performing maximal voluntary exercise, but the end-exercise heart rate (102 +/- 16 bpm) was lower than expected for this intensity of exercise. In conclusion, FES-induced unloaded cycling leads to exaggerated responses of pulmonary gas exchange and long time constants in patients with SCI. The delayed kinetics may be due in part to a blunted increase in heart rate in addition to severe deconditioning.     

Muscle atrophy is prevented in patients with acute spinal cord injury using functional electrical stimulation

Severe muscle atrophy occurs rapidly following traumatic spinal cord injury (SCI). Previous research shows that neuromuscular or 'functional' electrical stimulation (FES), particularly FES-cycle ergometry (FES-CE) can cause muscle hypertrophy in individuals with chronic SCI (> 1 year post-injury). However, the modest degree of hypertrophy in these already atrophied muscles has lessened earlier hopes that FES therapy would reduce secondary impairments of SCI. It is not known whether FES treatments are effective when used to prevent, rather than reverse, muscle atrophy in individuals with acute SCI. This study explored whether unloaded isometric FES contractions (FES-IC) or FES-CE decreased subsequent muscle atrophy in individual with acute SCI (< 3 months post-injury). Twenty-six subjects, 14-15 weeks post-traumatic SCI, were assigned to control, FES-IC, or FES-CE against progessively increasing resistance. Subjects were involved in the study for 3 or 6 months. Total body lean body mass (TB-LBM), lower limb lean body mass (LL-LBM), and gluteal lean body mass (G-LBM) were determined before the study, and at 3 and 6 months using dual energy X-ray absorptiometry (DEXA). Controls lost an average of 6.1%, 10.1%, 12.4%, after 3 months and 9.5%, 21.4%, 26.8% after 6 months in TB-LBM, LL-LBM and G-LBM respectively. Subjects in the FES-IC group consistently lost less lean body mass than controls, however, only 6 month G-LBM loss was significantly attenuated in this group relative to the controls. In the FES-CE group, LL-LBM and G-LBM loss were prevented at both 3 and 6 months, and TB-LBM loss was prevented at 6 months. In addition, FES-CE significantly increased G-LBM and LL-LBM after 6 months of training relative to pre-training levels. Within the control group, there was no significant relationship between LL-LBM loss (3 and 6 months) and the number of days between injury and baseline measurement. In summary, this study shows that FES-CE, but not FES-IC, training prevents muscle atrophy in acute SCI after 3 months of training, and causes significant hypertrophy after 6 months. The magnitude of differences in regionalized LBM between controls and FES-CE subject raises hopes that such treatment may indeed be beneficial in preventing secondary impairments of SCI if employed before extensive post-injury atrophy occurs.     

Restoration of gait by functional electrical stimulation for spinal cord injured patients

In this clinical study, we report the results of functional electrical stimulation for the ambulation of paraplegic patients without long leg braces (LLB), according to the Parastep approach. Of 13 SCI patients with complete neurological lesions included in this trial, 12 progressed to independent ambulation with the aid of the Parastep. The average walking distance was 76 m, with a maximum of 350 m, and the mean speed 0.2 m s-1. Compared to the situation with long leg braces, which in fact are given up by most paraplegic patients, long term home use seems to be much more important. Tolerance of this method is satisfactory. The psychological benefits of the device are remarkable. From this experience, it is concluded that this method is valuable for the restoration of standing and walking in the long term management of spinal cord injury patients.     

A dynamic model of the hand with application in functional neuromuscular stimulation

Potential hand function in people with tetraplegia was evaluated using a three-dimensional dynamic mathematical model. The model was used to evaluate hand positioning, grasp force, and the outcome of surgeries such as tendon transfers and joint fusion, in situations typical of those encountered when using functional neuromuscular stimulation to restore function in people with tetraplegia. In the model, the hand is treated as a jointed multibody system. Each joint is subjected to muscle moments, passive joint moment, and moments due to grasp forces. Model simulations showed that function was highly dependent on both muscle strength and joint passive moments. The potential for tendon transfers, such as the Zancolli-lasso and intrinsicplasty, plasty, to improve hand function was demonstrated, but their value is subject-dependent. It was also shown that activation of multiple thumb muscles (adductor pollicis, abductor pollicis brevis, and flexor pollicis longus) without interphalangeal joint fusion can provide convenient lateral pinch posture with approximately 70% more grip force than a currently used method, which includes joint fusion but requires only one muscle. Finally, a grasp protocol was introduced and shown successful in palmar grasp and hold of movable cylindrical objects using only extrinsic muscles, provided the fingers could be extended sufficiently to enclose the object.     

Theoretical evaluation of peripheral nerve stimulation during MRI with an implanted spinal fusion stimulator

This study examines the requirements for nerve excitation near a spinal fusion implant during magnetic resonance imaging. The implant is the Spinal Fusion SpF device manufactured by Electro Biology Inc. The electric field induced within the biological medium was calculated using a three-dimensional finite difference model (described in a separate paper by Beuchler et al. from the University of Utah). Magnetic thresholds were obtained for excitation of myelinated nerve fibers that are near the implant. Minimum (rheobase) thresholds were determined for long duration dB/dt pulses, as well as strength-duration time constants (from which thresholds at other durations could be determined) for various geometries between the implant and a myelinated nerve fiber. The lowest thresholds occur when a large (20-microm diameter) fiber is situated near the bare tip of a wire from the implant, and a long duration (2 ms) stimulus is provided for which dB/dt is constant and monophasic. Magnetic thresholds for shorter durations of dB/dt are higher in accordance with a strength-duration law. In a magnetic field having a time derivative of 10 T/s that is uniform over the torso, nerve excitation is possible under worst-case conditions only for nerve fibers that are within 0.14 mm of the bare wire tip of the implant. With 20 T/s, excitation is possible only within 1 mm of the wire tip.     

Evaluation of patterned stimulation for use in surface functional electrical stimulation systems

From a gerontological point of view, social work which accompanies care processes is absolutely necessary. The social production of care depends crucially on an appropriate attention toward the fitting between informal and formal help systems. Social work can support these fitting processes both on a firm level and on a neutral level. Some specific attributes of social work with elder care-dependant living in their private homes are discussed, such as threatening, difficult or ashaming aspects, as well as the necessity of all involved persons agreeing in the developed help-planning process. Practice research and Social science perspectives are discussed as appropriate reference system for life-world orientated social work with informal caregiving arrangements. Concerning the support of informal caregivers as an important example of ambulant social work with elder people, some dimensions of theoretical and practical professionality are proposed.     

Clinical experience of functional electrical stimulation in complete paraplegia

In the Riordan (bridle) transfer, the posterior tibialis muscle as motor is routed through the interosseous membrane and anastomosed into a "bridle" formed by the distal tibialis anterior and peroneus longus muscles. In theory, the bridle provides inversion/eversion balance even if the transfer effects only tenodesis. However, the procedure has been criticized because its insertion is not into bone. This review analyzes the use of bridle transfer in flaccid paresis involving musculature innervated by the peroneal nerve. Surgery was performed 1 to 3 years after injury for patients with traumatic etiology. Ten patients are reviewed at 61 months' mean follow-up. Eight patients had traumatic peroneal nerve loss. Two had neuromuscular etiology. Evaluation included review of records, telephone interviews, and physical examinations. Data on functional status included walking barefoot running, need for bracing, return to duty, and patient satisfaction. Physical examination recorded ankle position and motions, gait findings, and results of static electromyograms. All patients were able to walk barefoot, but 6 of 10 had a mild to moderate limp. Five patients returned to running initially; only two were able to keep running. Nine patients were brace-free initially (polio sequela required bracing initially), and four others returned to bracing. Of these, two experienced an acute "tearing" and dorsiflexion loss, one sustained a prolonged gradual loss of dorsiflexion, and one sustained a contralateral cerebrovascular accident. Only three of seven patients returned to active duty, and one is on jump status. All patients were satisfied with their initial result. Only two patients had no detectable swing phase problems (both returned to active duty). Five patients had peroneal nerve exploration with repair or neurolysis; two of them sustained complete transections. Postoperative electromyograms showed insignificant, if any, nerve return. The Riordan transfer works well for neuromuscular flaccid paresis and in patients with peroneal nerve injuries with low demands. It may stretch out over time to the point of acute failure in patients with high demands. Concurrent peroneal nerve exploration and repair did not seem to be beneficial in this small study.     

Augmented upper body contribution to oxygen uptake during upper body exercise with concurrent leg functional electrical stimulation in persons with spinal cord injury

The purpose of this pilot study was to compare the contribution of upper body musculature to VO2 with and without concurrent leg FES (LFES). Eight subjects with spinal cord injury, lesion levels range C6-T12, performed upper body exercise (UBE) during no LFES (NOS), LFES at 40 mA (LOS), and 80 mA (HIS), at rest, 60% and 80% of VO2peak. Resting VO2 values were obtained during NOS, LOS and HIS conditions and were then subtracted from their respective whole body VO2 values to give an estimate of upper body VO2. Small and non significant increases were found in the HIS vs NOS condition at 60% VO2peak. Larger differences of 7.8% were found in the HIS vs NOS condition at 80% VO2peak (11.35+/-3.8 ml kg(-1) min(-1) to 12.24+/-4.0 ml kg(-1) min(-1)), although this too was not significant, perhaps due to the small number of subjects in this study and the consequently low statistical power to detect a significant difference. We discuss the implications for these preliminary results in the context of the existing literature on this topic.     

Quality of semen obtained by penile vibratory stimulation in men with spinal cord injuries: observations and predictors

Previous studies have suggested that aging is associated with impaired behavioral performance and with decrements of N-methyl-D-aspartate (NMDA) receptors in the rat hippo-campus. Other studies have indicated that chronic treatment with nimodipine, a Ca2+ channel antagonist, prevents the age-related decline in performance by rats in behavioral tasks. Therefore, we tested whether nimodipine altered binding of [3H]CGS 19755 to hippocampal NMDA receptors in rats whose performance on a 14-unit T maze had been tested previously (14). No significant age difference was observed in [3H]CGS 19755 binding in hippocampi from old Fischer-344 rats (27 months) as compared with mature but not senescent rats (9 months); however, old rats that received chronic treatment with a low dose of nimodipine (20 mg pellets implanted subcutaneously twice during 70 days of treatment) showed higher levels of binding. A high dose of nimodipine (40 mg pellets implanted by the same route and at the same times as the low dose) was without effect on [3H]CGS 19755 binding, although aged rats given this treatment performed better in the maze than rats that received no nimodipine or the low dose. In a second experiment comparing hippocampi of young (4 months) and old (24 months) rats, saturation studies confirmed the lack of an age difference in [3H]CGS 19755 binding. The findings suggest that neither the age-related decline in maze performance nor the enhancement of behavior by nimodipine depend upon changes in hippocampal NMDA receptors.     

Stereotactic transcranial magnetic stimulation: correlation with direct electrical cortical stimulation

OBJECTIVE: To evaluate stereotactic transcranial magnetic stimulation (TMS) as a tool for presurgical functional mapping of human motor cortex. METHODS: Transcranial magnetic stimulation using a frameless stereotactic system was performed in two patients with tumors near the central sulcus. TMS motor function maps were plotted on the patients' three-dimensional volumetric magnetic resonance imaging data and compared with direct electrical cortical stimulation at surgery with the patient under local anesthesia. RESULTS: Stereotactic TMS was well tolerated by both patients and was consistent with known somatotopic representation of human motor cortex. The results demonstrated a good correlation between the TMS and electrical cortical stimulation maps, with all TMS responses eliciting more than 75% of the maximum motor evoked potential falling within 1 cm of the electrical cortical stimulation site. CONCLUSIONS: Our findings indicate that stereotactic TMS is feasible and can provide accurate noninvasive localization of cortical motor function. It may prove to be a useful method for presurgical planning.     

Prospective outcome evaluation of spinal cord stimulation in patients with intractable leg pain

STUDY DESIGN: The results of spinal cord stimulation were prospectively evaluated using both subjective patient self-report measures and objective physical functional testing. OBJECTIVES: The purpose of this study was to evaluate prospectively the effects of spinal cord stimulation implantation, performed with the patient awake and providing feedback, in patients with primary reports of intractable leg pain. SUMMARY OF BACKGROUND DATA: Spinal cord stimulation has been used for treating chronic pain of many types. However, even among those with intractable lower extremity pain, the outcome results have shown great variability. METHODS: The surgical procedure was performed with the patient awake and providing feedback to ensure optimal pain relief from the lead placement. The study group comprised 40 patients, ranging in age from 28 to 86 years. The average symptom duration was 65.4 months, and the average number of prior lumbar spine surgeries was 2.3 (range, 1 to 8). The primary data collection periods were preoperative, 6 weeks after, and 12 and 24 months after surgery. RESULTS: Statistically significant improvement in isometric lower extremity function was demonstrated 6 weeks after the spinal cord stimulation implantation. In the more painful leg, the performance increased from 457.5 ft-lb-sec to 629.8 ft-lb-sec (P < 0.01). The performance remained significantly improved at the 12- and 24-month follow-ups. Significant improvement was demonstrated on the physical scale of the Sickness Impact Profile at 6 weeks. At 24 months, all three scales (physical, psychological, and other) as well as the total score were significantly improved. Statistically significant decreases in pain, assessed by changes in visual analog scale scores, were noted in the legs, when walking, and in overall lifestyle. The use of narcotic medication decreased at all follow-up periods. At least 66% of the patients who were taking narcotics before spinal cord stimulation were taking reduced amounts or no narcotics 2 years later. At the time of the 24-month follow-up, at least 70% of patients reported that the procedure helped them, and would recommend it to someone with similar symptoms. CONCLUSIONS: Spinal cord stimulation implantation can result in improved physical function and decreased pain in patients who are carefully screened and in whom the implantation is performed with the patient awake to help ensure optimal pain-relieving lead placement.     

Pancreatic duct: morphologic and functional evaluation with dynamic MR pancreatography after secretin stimulation

Two sensitive reversed-phase high-performance liquid chromatographic fluorescence methods, with simple sample handling at the site of the patient, are described for the determination of the lactone and lactone plus carboxylate forms of 9-aminocamptothecin (9AC). For 9AC lactone, the sample preparation was a liquid-liquid extraction with acetonitrile-n-butyl chloride (1:4, v/v), whereas the sample preparation for 9AC total (lactone plus carboxylate) was a simple deproteinization with 5% perchloric acid-methanol (1:1, v/v), which results in the conversion of the carboxylate into the lactone form. The lower limits of quantitation were 50 pg/ml and 100 pg/ml for 9AC lactone and 9AC total, respectively. The within-run precisions at four tested concentrations were < or = 6.3% for 9AC lactone and < or = 5.3% for 9AC total. The between-run precisions were < or = 8.9% and < or = 5.6%, respectively. The assays were developed to enable pharmacological analysis of 9AC in a bioavailability and oral phase I study in patients with solid tumors.     

Pregnancy in women with spinal cord injuries

Most women with spinal cord injuries (SCI) resume normal reproductive function, can have sexual relationships, and become pregnant. Pregnancy is not contraindicated in women with SCI, but pregnant women with acute or chronic SCI pose unique challenges for perinatal health care providers. The normal physiologic changes of pregnancy may predispose women with SCI to potentially life-threatening complications, including autonomic hyperreflexia, pyelonephritis, respiratory insufficiency, thrombophlebitis, and unattended delivery of the infant. This article reviews the effect of SCI on female reproduction, pregnancy, and labor, and summarizes the treatment of the pregnant woman with a spinal cord injury.     

Perceptual consequences of electrical stimulation in the gustatory system.

To investigate the role of temporal coding in the neural processing of taste, trains of electrical pulse of varying frequency were delivered to the nucleus of the solitary tract (NTS) in awake rats. The temporal patterns of these trains mimicked the temporal patterns of electrophysiological responses of single neurons to natural tastes. In Exp 1, water-deprived rats were first trained to lick water in an experimental chamber. On training days, licking water produced a sucroselike electrical pulse train in the NTS. At the end of these sessions, experimental animals were made ill by an injection of LiCl and subsequently learned to avoid licking when LiCl was paired with NTS stimulation. In Exp 2, rats refused to lick water when licking produced a quininelike pattern of NTS stimulation but licked enthusiastically when licking produced a pattern of NTS stimulation similar to the natural response to sucrose. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of electrical stimulation on colonic transit following spinal cord injury in cats

The distribution of type I collagen, the major component of human dermis, was characterized by immunohistochemistry in skin lesions of chromoblastomycosis, a chronic cutaneous mycosis, before and after a specific antifungal treatment with terbinafine to study the changes induced in the lesions by the treatment. Newly synthesized type I collagen was studied with an antibody directed against the aminoterminal propeptide of the molecule (PINP), whereas mature, cross-linked type I collagen was detected with an antibody against the carboxyterminal telopeptide of type I collagen (ICTP). The isopeptide N epsilon gamma-glutamyl lysine (N epsilon gamma GL), synthesized by transglutaminase and able to cross-link several components of the extracellular matrix, has also been investigated with two monoclonal antibodies to determine if it is involved in the stabilisation of the fibrotic cutaneous lesions. The degradative process involved in the remodelling has also been assessed by immunohistochemistry with anti-metalloproteinase (MMP-1 and MMP-9) and anti-tissue inhibitor (TIMP-1) antibodies. All tissue macrophages stained for CD68 and MMP-9, but not for MMP-1, while the polymorphonuclear neutrophils had an elastase and a weak MMP-9 phenotype. The fibroblasts of fibrotic areas stained constantly for N epsilon gamma GL and PINP. The immunostaining of extracellular matrix for ICTP and N epsilon gamma GL, and the number of PINP-positive fibroblasts, decreased significantly after one year of antifungal treatment. Terbinafine treatment decreases the synthesis of type I collagen and leads to a partial reversal of the cutaneous fibrotic lesions, independently of the cure of the fungal infection.     

Operant conditioning of spinal stretch reflexes in patients with spinal cord injuries

Hyperactive spinal stretch reflexes (SSRs) often occur with spinal cord injuries (SCI). These altered SSRs may impair movement. Recent studies in monkeys and human subjects have indicated that the magnitude of SSRs can be modulated using operant conditioning. The purpose of this study was to determine whether hyperactive biceps brachii SSRs could be operantly conditioned downward. Seventeen chronic (> 1 year postlesion) spinal cord-injured patients participated. Subjects were trained to keep biceps background (prestretch) electromyographic (EMG) activity and elbow angle at predetermined levels prior to having the elbow rapidly extended by a torque motor to elicit the biceps SSR. All subjects participated in six baseline sessions over a 2-week period. Then, subjects were randomly assigned to either control or training groups for the next 24 sessions over an 8-week period. By the end of the study, training subjects had significantly reduced biceps SSRs (t test, P < 0.001), while control subjects SSRs were not significantly reduced (t test, P > 0.05). The reduced SSRs persisted for up to 4 months following cessation of training. The results of this study support the hypothesis that hyperactive SSRs can be operantly conditioned downward in SCI patients.     

Magnetic and electrical stimulation in the rehabilitative treatment of patients with organic nervous system lesions]

89 patients with organic damages of nervous system with paralyses and pareses as the main symptoms in clinical pattern were treated. Their treatment was complex with application of impulse magnetic field and electrostimulation which permitted to achieve multilevel electrostimulation. The control group was formed by 49 patients with analogous diseases which were treated by sinusoidal current electrostimulation only. Combined application of magnetic stimulation and electrostimulation was more effective. That was confirmed by data of roentgenographic and electromyographic studies.     

Morphine-naloxone interaction in the central cholinergic system: the influence of subcortical lesioning and electrical stimulation

1 The opiate antagonist naloxone, injected or topically applied to the cerebral cortex, had no significant effect on the spontaneous output of cortical acetylcholine (ACh) in rats. 2 Morphine (2.5 mg/kg) administered intravenously inhibited the release of cortical ACh. A subsequent injection of naloxone rapidly reversed morphine-induced inhibition, and produced a sustained increase in the release of ACh. Topical application of naloxone solutions, after morphine, produced a slow and weak reversal of its inhibitory action. 3 Destruction of the medial thalamus abolished both the inhibitory effects of morphine on the cortical ACh release, and its antagonism by naloxone administered after the agonist. 4 Injection of naloxone in a low dose (0.1 mg/kg) increased the release of cortical ACh provoked by electrical stimulation of either the medial thalamus or the reticular formation in normal rats. In the morphine-dependent rat, naloxone also facilitated the evoked release and its action was greater than in control animals. The facilitatory effect of naloxone on the cortical release evoked by stimulation of the medial thalamus was greater than its effect on the release evoked by stimulation of the reticular formation in both normal and morphine-dependent rats. 5 Naltrexone, a narcotic antagonist, also facilitated the electrically stimulated release of cortical ACh. 6 It is suggested that (a) morphine and naloxone act at a subcortical site, probably the medial thalamus, to modify the cortical ACh release and that (b) naloxone may facilitate the electrically-induced release of ACh in the CNS by antagonizing the effect of the endogenous morphine-like factor, enkephalin.