Lynne R. Sheffler

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. Muscle Nerve, 2007

Peroneal nerve stimulation versus an ankle foot orthosis for correction of footdrop in stroke: Impact on functional ambulation

Objective. To compare the efficacy of the Odstock Dropped-Foot Stimulator (ODFS), a transcutaneous peroneal nerve stimulation device, versus an ankle foot orthosis (AFO) in improving functional ambulation of chronic stroke survivors. Intervention. Fourteen chronic stroke survivors with foot-drop participated in the study. Participants received ambulation training under 3 test conditions: 1) ODFS, 2) customized AFO, and 3) no device. Each participant was evaluated using the modified Emory Functional Ambulation Profile under the 3 test conditions. All participants were evaluated with a post-evaluation survey to solicit device feedback and preferences. Results. Functional ambulation with the AFO was significantly improved, relative to no device, on the floor (P = 0.000), carpet (P = 0.013), and “up and go” test (P = 0.042). There was a trend toward significance on the obstacle (P = 0.092) and stair (P = 0.067) trials. Functional ambulation with the ODFS was significantly improved, relative to no device, on the carpet(P = 0.004). A trend toward significance on floor (P = 0.081), obstaclxze (P = 0.092), and stair (P = 0.079) trials was observed. The difference in functional ambulation between the AFO and ODFS showed a trend toward statistical significance on floor (P = 0.065) and up and go (P = 0.082) trials only. Given a choice between the ODFS and AFO for long-term correction of footdrop, participants indicated a preference for the ODFS. Conclusion. The AFO and the ODFS may be comparable in their effect on improving functional ambulation as compared to no device. Specific characteristics of the ODFS may make it a preferred intervention by stroke survivors. More rigorously controlled trials are needed to confirm these findings.

Neuromuscular Electrical Stimulation for Motor Restoration in Hemiplegia

Abstract Clinical applications of neuromuscular electrical stimulation (NMES) in stroke rehabilitation provide both therapeutic and functional benefits. Therapeutic applications include upper and lower limb motor relearning and reduction of poststroke shoulder pain. There is growing evidence that NMES, especially those approaches that incorporate task-specific strategies, is effective in facilitating upper and lower limb motor relearning. There is also strong evidence that NMES reduces poststroke shoulder subluxation and pain. Functional applications include upper and lower limb neuroprostheses. Lower limb neuroprostheses in the form of peroneal nerve stimulators is effective in enhancing the gait speed of stroke survivors with foot-drop. The development of hand neuroprostheses is in its infancy and must await additional fundamental and technical advances before reaching clinical viability. The limitations of available systems and future developments are discussed.

Randomized Controlled Trial of Surface Peroneal Nerve Stimulation for Motor Relearning in Lower Limb Hemiparesis

OBJECTIVE To compare the motor relearning effect of a surface peroneal nerve stimulator (PNS) versus usual care on lower limb motor impairment, activity limitation, and quality of life among chronic stroke survivors. DESIGN Single-blinded randomized controlled trial. SETTING Teaching hospital of academic medical center. PARTICIPANTS Chronic stroke survivors (N=110; >12wk poststroke) with unilateral hemiparesis and dorsiflexion strength of ≤4/5 on the Medical Research Council scale. INTERVENTIONS Subjects were stratified by motor impairment level and then randomly assigned to ambulation training with either a surface PNS device or usual care (ankle-foot orthosis or no device) intervention. Subjects were treated for 12 weeks and followed up for 6 months posttreatment. MAIN OUTCOME MEASURES Lower limb portion of the Fugl-Meyer (FM) Assessment (motor impairment), the modified Emory Functional Ambulation Profile (mEFAP) performed without a device (functional ambulation), and the Stroke Specific Quality of Life (SSQOL) scale. RESULTS There was no significant treatment group main effect or treatment group by time interaction effect on FM, mEFAP, or SSQOL raw scores (P>.05). The time effect was significant for the 3 raw scores (P<.05). However, when comparing average change scores from baseline (t1) to end of treatment (t2, 12wk), and at 12 weeks (t3) and 24 weeks (t4) after end of treatment, significant differences were noted only for the mEFAP and SSQOL scores. The change in the average scores for both mEFAP and SSQOL occurred between t1 and t2, followed by relative stability thereafter. CONCLUSIONS There was no evidence of a motor relearning effect on lower limb motor impairment in either the PNS or usual-care groups. However, both the PNS and usual-care groups demonstrated significant improvements in functional mobility and quality of life during the treatment period, which were maintained at 6-month follow-up.

Improvement in Functional Ambulation as a Therapeutic Effect of Peroneal Nerve Stimulation in Hemiplegia: Two Case Reports

Two chronic stroke survivors who utilized an ankle foot orthosis (AFO) prior to study entry were evaluated at baseline and after 4 weeks of daily use of a surface peroneal nerve stimulator. Participants were assessed without their dorsiflexor assistive device, using the modified Emory Functional Ambulation Profile (mEFAP). The participants demonstrated improvement in all 5 components of the mEFAP relative to baseline. These case reports indicate that enhanced functional ambulation may be an important therapeutic effect of peroneal nerve stimulation. Potential mechanisms are discussed. Controlled trials are needed to demonstrate a cause-and-effect relationship.

Spatiotemporal, Kinematic, and Kinetic Effects of a Peroneal Nerve Stimulator Versus an Ankle Foot Orthosis in Hemiparetic Gait

Background. The relative effect of a transcutaneous peroneal nerve stimulator (tPNS) and an ankle foot orthosis (AFO) on spatiotemporal, kinematic, and kinetic parameters of hemiparetic gait has not been well described. Objective. To compare the relative neuroprosthetic effect of a tPNS with the orthotic effect of an AFO using quantitative gait analysis (QGA). Design. In all, 12 stroke survivors underwent QGA under 3 device conditions: (1) no device (ND), (2) AFO, and (3) tPNS. A series of repeated-measures analyses of variance (rmANOVAs) were performed with dorsiflexion status (presence or absence of volitional dorsiflexion) as a covariate to compare selected spatiotemporal, kinematic, and kinetic parameters for each device condition. Post hoc pairwise comparisons and/or subset analysis by dorsiflexion status were performed for significant effect. Results. Stride length was improved with both the AFO (P = .035) and the tPNS (P = .029) relative to ND. Those with absent dorsiflexion had longer stride length with the tPNS relative to ND (P = .034) and a higher walking velocity with a tPNS relative to the AFO (P = .015). There was no device effect on dorsiflexion angle at initial contact; however, a significant Device × Dorsiflexion status interaction effect favored the AFO relative to ND (P = .025) in those with dorsiflexion present. Conclusion. This study suggests that level of motor impairment may influence the relative effects of the tPNS and AFO devices in chronic hemiparetic gait; however, the small sample size limits generalizability. Future studies are necessary to determine if motor impairment level should be considered in the clinical prescription of these devices.

Neuroprosthetic Effect of Peroneal Nerve Stimulation in Multiple Sclerosis: A Preliminary Study

OBJECTIVE To determine the neuroprosthetic effect of a peroneal nerve stimulator on tasks of functional ambulation in multiple sclerosis (MS). DESIGN A single point-in-time assessment of functional ambulation tasks under the conditions of no device and peroneal nerve stimulator. SETTING Outpatient academic medical center. PARTICIPANTS Participants (N=11) with diagnosis of MS (>6mo), dorsiflexion weakness, and prior usage of an ankle-foot orthosis. INTERVENTION Surface peroneal nerve stimulator for ambulation. MAIN OUTCOME MEASURES Timed 25-foot Walk portion of the MS Functional Composite; Floor, Carpet, Up and Go, Obstacle, and Stair components of the Modified Emory Functional Ambulation Profile. RESULTS Peroneal nerve stimulator-Stair performance was significantly enhanced (P=.05) versus no device, and statistical significance was approached for peroneal nerve stimulator-Obstacles (P=.09) versus no device. There were no significant differences between peroneal nerve stimulator and no device conditions in the remaining outcome measures. CONCLUSIONS The neuroprosthetic effect of the peroneal nerve stimulator is modest relative to no device in the performance of specific functional tasks of ambulation in MS gait. A longitudinal, controlled trial is needed to show effectiveness.

Relationship Between Body Mass Index and Rehabilitation Outcomes in Chronic Stroke

ObjectiveThe aim of this study was to evaluate the relationship between body mass index (BMI) and change in motor impairment and functional mobility after a gait rehabilitation intervention in chronic stroke subjects. DesignCorrelation and linear regression analyses of pretreatment and end-of-treatment Fugl-Meyer scores and modified Emory Functional Ambulation Profile scores from hemiparetic subjects (n = 108, >3 mos post stroke) who participated in a randomized controlled trial comparing two 12-wk ambulation training treatments were generated. ResultsA series of linear regression models that controlled for age, sex, stroke type, interval post-stroke, and training device found the change in the Fugl-Meyer score to be significantly negatively associated with pretreatment BMI (&bgr; = −0.207, P = 0.036) and the change in the “up and go” modified Emory Functional Ambulation Profile score to be significantly positively associated with BMI (&bgr; = 0.216, P = 0.03). Changes in modified Emory Functional Ambulation Profile scores in floor, carpet, obstacles, or stair climbing were not significantly associated with BMI. ConclusionsChronic stroke subjects with a higher BMI were less likely to demonstrate improvement in motor impairment and up and go functional mobility performance in response to ambulation training, irrespective of treatment intervention. Stroke rehabilitation clinicians should consider BMI when formulating rehabilitation goals. Further studies are necessary to determine whether obesity is a predictor of longer-term post-stroke motor and functional recovery.

Upper-Limb Recovery After Stroke A Randomized Controlled Trial Comparing EMG-Triggered, Cyclic, and Sensory Electrical Stimulation

Background and purpose. This study compared the effect of cyclic neuromuscular electrical stimulation (NMES), electromyographically (EMG)-triggered NMES, and sensory stimulation on motor impairment and activity limitations in patients with upper-limb hemiplegia. Methods. This was a multicenter, single-blind, multiarm parallel-group study of nonhospitalized hemiplegic stroke survivors within 6 months of stroke. A total of 122 individuals were randomized to receive either cyclic NMES, EMG-triggered NMES, or sensory stimulation twice every weekday in 40-minute sessions, over an 8 week-period. Patients were followed for 6 months after treatment concluded. Results. There were significant increases in the Fugl-Meyer Assessment [F(1, 111) = 92.6, P < .001], FMA Wrist and Hand [F(1, 111) = 66.7, P < .001], and modified Arm Motor Ability Test [mAMAT; time effect: F(1, 111) = 91.0, P < .001] for all 3 groups. There was no significant difference in the improvement among groups in the FMA [F(2, 384) = 0.2, P = .83], FMA Wrist and Hand [F(2, 384) = 0.4, P = .70], or the mAMAT [F(2, 379) = 1.2, P = .31]. Conclusions. All groups exhibited significant improvement of impairment and functional limitation with electrical stimulation therapy applied within 6 months of stroke. Improvements were likely a result of spontaneous recovery. There was no difference based on the type of electrical stimulation that was administered.

Technological Advances in Interventions to Enhance Poststroke Gait

Neurologic rehabilitation interventions may be either therapeutic or compensatory. Included in this article are lower extremity functional electrical stimulation, body weight-supported treadmill training, and lower extremity robotic-assisted gait training. These poststroke gait training therapies are predicated on activity-dependent neuroplasticity. All three interventions have been trialed extensively in research and clinical settings to show a positive effect on various gait parameters and measures of walking performance. This article provides an overview of evidence-based research that supports the efficacy of these three interventions to improve gait, as well as providing perspective on future developments to enhance poststroke gait in neurologic rehabilitation.