First-In-Human Demonstration of High Frequency Electrical Motor Nerve Block: Case Report.

ABSTRACT: This feasibility study tested the capability of high frequency stimulation (HFS) to block muscle contractions elicited by electrical stimulation of the same nerve proximally. During a tendon lengthening surgery in the forearm, the anterior interosseous nerve (AIN) was exposed. A specialized nerve cuff electrode was placed around the nerve, and a stimulating probe held on the nerve 1 cm proximal to the cuff electrode delivered pulses of current causing the pronator quadratus muscle to contract. Through the cuff electrode, 20 kHz HFS was delivered to the nerve for 10 seconds during proximal stimulation. HFS amplitudes between 5 and 10 mA peak-to-peak were tested to determine which produced complete and partial block of the electrically induced contractions. The minimum HFS amplitude that produced complete block was 8 mA, with lower amplitudes producing partial block. In all trials, muscle contractions resumed immediately after HFS was turned off. This demonstration of high frequency electrical nerve block is a milestone in the road to clinical implementation of HFS mediated motor block for spasticity.

Neurostimulation After Stroke.

Neural stimulation technology aids stroke survivors in regaining lost motor functions. This article explores its applications in upper and lower limb stroke rehabilitation. The authors review various methods to target the corticomotor system, including transcranial direct current stimulation, repetitive transcranial magnetic stimulation, and vagus nerve stimulation. In addition, the authors review the use of peripheral neuromuscular electrical stimulation for therapeutic and assistive purposes, including transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and functional electrical stimulation. For each, the authors examine the potential benefits, limitations, safety considerations, and FDA status.

Contralaterally controlled functional electrical stimulation video game therapy for hand rehabilitation after stroke: a randomized controlled trial.

PURPOSE: To estimate the effect of integrating custom-designed hand therapy video games (HTVG) with contralaterally controlled functional electrical stimulation (CCFES) therapy. METHODS: Fifty-two stroke survivors with chronic (>6 months) upper limb hemiplegia were randomized to 12 weeks of CCFES or CCFES + HTVG. Treatment involved self-administration of technology-mediated therapy at home plus therapist-administered CCFES-assisted task practice in the lab. Pre- and post-treatment assessments were made of hand dexterity, upper limb impairment and activity limitation, and cognitive function. RESULTS: No significant between-group differences were found on any outcome measure, and the average magnitudes of improvement within both groups were small. The incidence of technical problems with study devices at home was greater for the CCFES + HTVG group. This negatively affected adherence and may partially explain the absence of effect of HTVG. At end-of-treatment, large majorities of both treatment groups had positive perceptions of treatment efficacy and expressed enthusiasm for the treatments. CONCLUSION: This study makes an important contribution to the research literature on the importance of environmental factors, concomitant impairments, and technology simplification when designing technology-based therapies intended to be self-administered at home. This study failed to show any added benefit of HTVG to CCFES therapy.Clinicaltrials.gov (NCT03058796).

Contralaterally controlled functional electrical stimulation (CCFES) is an emerging therapy for upper limb rehabilitation after stroke that is designed, in part, to be self-administered at home.While movement-soliciting video games have shown promise in rehabilitation, this study failed to show a significant added benefit of integrating CCFES with hand therapy video games.For technology-based therapies intended to be self-administered at home, this study brings to light the importance of making every component of rehabilitation technology as user friendly and trouble-free as possible.For technology-based therapies intended to be self-administered at home, this study brings to light the importance of assuring that the home environment is conducive to home-based therapy.

Contralaterally Controlled Functional Electrical Stimulation Combined With Brain Stimulation for Severe Upper Limb Hemiplegia-Study Protocol for a Randomized Controlled Trial.

Background: Approximately two-thirds of stroke survivors experience chronic upper limb paresis, and of them, 50% experience severe paresis. Treatment options for severely impaired survivors are often limited. Rehabilitation involves intensively engaging the paretic upper limb, and disincentivizing use of the non-paretic upper limb, with the goal to increase excitability of the ipsilesional primary motor cortex (iM1) and suppress excitability of the undamaged (contralesional) motor cortices, presumed to have an inhibitory effect on iM1. Accordingly, brain stimulation approaches, such as repetitive transcranial magnetic stimulation (rTMS), are also given to excite iM1 and/or suppress contralesional motor cortices. But such approaches aimed at ultimately increasing iM1 excitability yield limited functional benefit in severely impaired survivors who lack sufficient ipsilesional substrate. Aim: Here, we test the premise that combining Contralaterally Controlled Functional Electrical Stimulation (CCFES), a rehabilitation technique that engages the non-paretic upper limb in delivery of neuromuscular electrical stimulation to the paretic upper limb, and a new rTMS approach that excites intact, contralesional higher motor cortices (cHMC), may have more favorable effect on paretic upper limb function in severely impaired survivors based on recruitment of spared, transcallosal and (alternate) ipsilateral substrate. Methods: In a prospective, double-blind, placebo-controlled RCT, 72 chronic stroke survivors with severe distal hand impairment receive CCFES plus cHMC rTMS, iM1 rTMS, or sham rTMS, 2X/wk for 12wks. Measures of upper limb motor impairment (Upper Extremity Fugl Meyer, UEFM), functional ability (Wolf Motor-Function Test, WMFT) and perceived disability are collected at 0, 6, 12 (end-of-treatment), 24, and 36 wks (follow-up). TMS is performed at 0, 12 (end-of-treatment), and 36 wks (follow-up) to evaluate inter-hemispheric and ipsilateral mechanisms. Influence of baseline severity is also characterized with imaging. Conclusions: Targeting of spared neural substrates and rehabilitation which engages the unimpaired limb in movement of the impaired limb may serve as a suitable combinatorial treatment option for severely impaired stroke survivors. ClinicalTrials No: NCT03870672.

Efficacy of contralaterally controlled functional electrical stimulation compared to cyclic neuromuscular electrical stimulation and task-oriented training for recovery of hand function after stroke: study protocol for a multi-site randomized controlled trial.

BACKGROUND: Multi-site studies in stroke rehabilitation are important for determining whether a technology and/or treatment can be successfully administered by sites other than the originating site and with similar positive outcomes. This study is the first multi-site clinical trial of a novel intervention for post-stroke upper limb rehabilitation called contralaterally controlled functional electrical stimulation (CCFES). Previous pilot and single-site studies showed positive effects of CCFES on upper limb impairment and hand dexterity in stroke survivors. The main purpose of this study is to confirm and demonstrate the efficacy of CCFES in a larger group of most likely responders across multiple clinical sites. METHODS: Up to 129 stroke survivors with moderate to severe upper extremity hemiparesis at 4 clinical trial sites will be randomized to CCFES, cyclic neuromuscular electrical stimulation (cNMES), or task-oriented-training (TOT). Participants will receive 12 weeks of group-specific therapy. Blinded assessments of upper limb impairment and activity limitation, quality of life, and neurophysiology will be used to compare outcomes at baseline, after treatment, and up to 6 months post-treatment. The primary endpoint is change in dexterity from baseline to 6 months post-treatment. DISCUSSION: Loss of hand function following stroke is a major rehabilitation problem affecting millions of people per year globally. More effective rehabilitation therapies are needed to restore hand function in these individuals. This study will determine whether CCFES therapy produces greater improvements in upper extremity function than cNMES or TOT, and will begin to elucidate the different mechanisms underlying each of the three treatments. This multi-site study is a critical step in advancing a novel method of rehabilitation toward clinical translation and widespread dissemination. TRIAL REGISTRATION: ClinicalTrials.gov NCT03574623 . Registered prior to first enrollment; July 2, 2018.

Home-Based Functional Electrical Stimulation-Assisted Hand Therapy Video Games for Children With Hemiplegia: Development and Proof-of-Concept.

We describe the development and three case reports of a home-based intervention for children with hand hemiplegia that integrates custom video games with contralaterally controlled functional electrical stimulation (CCFES). With CCFES, stimulated opening of the more-affected hand is modulated by volitional opening of the less-affected hand. Video games that solicit goal-oriented, skill-requiring movement have shown promise for treating hemiplegia, but they have not previously been combined with electrical stimulation in children. Three children ages 8, 9, and 11 with moderate-to-severe hand hemiplegia were assigned six weeks of therapy in lab and at home. The goal was to determine if children could tolerate 9 lab treatment sessions and administer up to 7.5 hrs/wk of CCFES video game therapy at home. The feasibility of this intervention for home use was assessed by device logs, end-of-treatment interviews, and motor function/impairment assessments. With caregiver help, the children were all able to attend 9 lab sessions and built up to 7.5 hrs/wk of therapy by week 3. They averaged 5-7 hrs/wk of home intervention overall. Motor outcomes improved for all three participants at treatment end, but mostly regressed at 4-weeks follow-up. Individual improvements at treatment end exceeded minimum detectable or clinically important thresholds for Assisting Hands Assessment, Fugl-Meyer Assessment, and Melbourne Motor Assessment 2. We found preliminary indications that CCFES-integrated video game therapy can provide a high dose of hand motor control therapy at home and in the lab. Improvements in motor outcomes were also observed, but more development and study is needed.

Adding Contralaterally Controlled Electrical Stimulation of the Triceps to Contralaterally Controlled Functional Electrical Stimulation of the Finger Extensors Reduces Upper Limb Impairment and Improves Reachable Workspace but not Dexterity: A Randomized Controlled Trial.

OBJECTIVE: Different methods of neuromuscular electrical stimulation may be used for poststroke upper limb rehabilitation. This study evaluated the effects of contralaterally controlled functional electrical stimulation of the triceps and finger extensors. DESIGN: This is a randomized controlled trial of 67 participants who were less than 2 yrs poststroke and assigned to the following: (a) arm + hand contralaterally controlled functional electrical stimulation, (b) hand contralaterally controlled functional electrical stimulation, or (c) arm + hand cyclic neuromuscular electrical stimulation. Participants were prescribed 10 sessions/week of assigned electrical stimulation at home plus 24 sessions of functional task practice in the laboratory for 12 wks. The primary outcome measure was the Box and Blocks Test. Secondary measures included reachable workspace, Upper Extremity Fugl-Meyer, Stroke Upper Limb Capacity Scale, Arm Motor Abilities Test, and Motor Activity Log. RESULTS: There were no significant between-group differences on the Box and Blocks Test. At 6 mos after treatment, arm + hand contralaterally controlled functional electrical stimulation improved reachable workspace more than hand contralaterally controlled functional electrical stimulation, between-group difference of 264 (95% confidence interval = 28-500) cm and more than arm + hand cyclic neuromuscular electrical stimulation, between-group difference of 281 (95% confidence interval = 22-540) cm. Arm + hand contralaterally controlled functional electrical stimulation improved Upper Extremity Fugl-Meyer score more than hand contralaterally controlled functional electrical stimulation, between-group difference of 6.7 (95% confidence interval = 0.6-12.7). The between-group differences on the Stroke Upper Limb Capacity Scale and Arm Motor Abilities Test were not significant. CONCLUSIONS: Adding contralaterally controlled elbow extension to hand contralaterally controlled functional electrical stimulation does not improve on gains in hand dexterity, but it further reduces upper limb impairment and improves reachable workspace measured in the laboratory. However, these additional benefits may not be large enough to be perceived by stroke survivors when they are performing activities of daily living at home.

Ability of people with post-stroke hemiplegia to self-administer FES-assisted hand therapy video games at home: An exploratory case series.

INTRODUCTION: This article describes the development and initial clinical testing of an innovative home-based treatment for upper extremity hemiplegia that integrates contralaterally controlled functional electrical stimulation with hand therapy video games. METHODS: We explored the ability of seven participants with moderate-to-severe hand impairment to self-administer 12 weeks of contralaterally controlled functional electrical stimulation video game therapy at home for 10 h/week and in-lab with a therapist for four h/week. Clinical suitability was assessed by device usage logs, qualitative surveys, and clinical motor and cognitive outcomes. RESULTS: Three participants completed the study with > 95% compliance and four did not. Factors linked to incompletion included development of trigger finger in the non-paretic hand, acceptance of a new full-time job, residence relocation, and persistence of drowsiness from anti-spasticity medication. Those who completed the treatment perceived qualitative benefits and experienced gains in motor and cognitive outcomes. CONCLUSION: Individuals with moderate-to-severe chronic post-stroke upper extremity hemiplegia can self-administer contralaterally controlled functional electrical stimulation video game therapy for up to 90 min/day at home. We also identified social and physiological factors that may preclude its use for daily home treatment. Further studies are warranted and are in progress to estimate treatment effect and optimal dose of this intervention.

Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke.

Background. Upper-limb chronic stroke hemiplegia was once thought to persist because of disproportionate amounts of inhibition imposed from the contralesional on the ipsilesional hemisphere. Thus, one rehabilitation strategy involves discouraging engagement of the contralesional hemisphere by only engaging the impaired upper limb with intensive unilateral activities. However, this premise has recently been debated and has been shown to be task specific and/or apply only to a subset of the stroke population. Bilateral rehabilitation, conversely, engages both hemispheres and has been shown to benefit motor recovery. To determine what neurophysiological strategies bilateral therapies may engage, we compared the effects of a bilateral and unilateral based therapy using transcranial magnetic stimulation. Methods. We adopted a peripheral electrical stimulation paradigm where participants received 1 session of bilateral contralaterally controlled functional electrical stimulation (CCFES) and 1 session of unilateral cyclic neuromuscular electrical stimulation (cNMES) in a repeated-measures design. In all, 15 chronic stroke participants with a wide range of motor impairments (upper extremity Fugl-Meyer score: 15 [severe] to 63 [mild]) underwent single 1-hour sessions of CCFES and cNMES. We measured whether CCFES and cNMES produced different effects on interhemispheric inhibition (IHI) to the ipsilesional hemisphere, ipsilesional corticospinal output, and ipsilateral corticospinal output originating from the contralesional hemisphere. Results. CCFES reduced IHI and maintained ipsilesional output when compared with cNMES. We found no effect on ipsilateral output for either condition. Finally, the less-impaired participants demonstrated a greater increase in ipsilesional output following CCFES. Conclusions. Our results suggest that bilateral therapies are capable of alleviating inhibition on the ipsilesional hemisphere and enhancing output to the paretic limb.

Neuromodulation for Functional Electrical Stimulation.

This article describes the application of neuromodulation in different ways to motor recovery, to replace lost function, or to improve function of organ systems for those who have experienced spinal cord injury or stroke. Multiple devices have been developed and are currently available for use whereas others are still in the experimental stage. Multiple uses of neuromodulation are described.

Convergent Validity and Responsiveness of the SULCS.

OBJECTIVE: To evaluate the convergent validity and responsiveness of the Stroke Upper Limb Capacity Scale (SULCS) in comparison to the Arm Motor Ability Test (AMAT), the Box and Blocks Test (BBT), and the upper limb Fugl-Meyer Assessment (FMA). The SULCS is a relatively new measure that was designed to be easier to score and less time consuming than some existing measures. DESIGN: Prospective repeated-measures design. SETTING: Clinical research laboratory of a large public hospital. PARTICIPANTS: Patients (N=61) <2 years poststroke with moderate to severe upper limb hemiparesis. INTERVENTION: Participants received 12 weeks of therapy that included neuromuscular electrical stimulation of the paretic finger and thumb extensors. The SULCS, AMAT, BBT, and FMA were administered at weeks 0, 6, 12 (end of therapy), 20, 28, and 36 (6mo post-therapy). MAIN OUTCOME MEASURES: Convergent validity was evaluated with Spearman's correlation coefficients between pairs of measures at each time point. Responsiveness from 0 to 12 weeks and 0 to 36 weeks was evaluated with the standardized response mean (SRM). RESULTS: The SULCS demonstrated strong correlation with the AMAT (ρ=0.81-0.93), BBT (ρ=0.73-0.92), and FMA (ρ=0.78-0.92), at all 6 time points. All 4 measures had moderate to large SRMs (SULCS, 0.71-0.77; AMAT, 0.83-0.97; BBT, 0.73-0.82; FMA, 0.75-0.76). There was no significant difference in responsiveness among the 4 measures. CONCLUSIONS: The results support the use of the SULCS to measure upper limb capacity in patients who are less than 2 years poststroke with moderate to severe hemiplegia.

The effect of motor overflow on bimanual asymmetric force coordination.

Motor overflow, typically described in the context of unimanual movements, refers to the natural tendency for a 'resting' limb to move during movement of the opposite limb and is thought to be influenced by inter-hemispheric interactions and intra-cortical networks within the 'resting' hemisphere. It is currently unknown, however, how motor overflow contributes to asymmetric force coordination task accuracy, referred to as bimanual interference, as there is need to generate unequal forces and corticospinal output for each limb. Here, we assessed motor overflow via motor evoked potentials (MEPs) and the regulation of motor overflow via inter-hemispheric inhibition (IHI) and short-intra-cortical inhibition (SICI) using transcranial magnetic stimulation in the presence of unimanual and bimanual isometric force production. All outcomes were measured in the left first dorsal interosseous (test hand) muscle, which maintained 30% maximal voluntary contraction (MVC), while the right hand (conditioning hand) was maintained at rest, 10, 30, or 70% of its MVC. We have found that as higher forces are generated with the conditioning hand, MEP amplitudes at the active test hand decreased and inter-hemispheric inhibition increased, suggesting reduced motor overflow in the presence of bimanual asymmetric forces. Furthermore, we found that subjects with less motor overflow (i.e., reduced MEP amplitudes in the test hemisphere) demonstrated poorer accuracy in maintaining 30% MVC across all conditions. These findings suggest that motor overflow may serve as an adaptive substrate to support bimanual asymmetric force coordination.

The Effect of Peripheral Nerve Stimulation on Shoulder Biomechanics: A Randomized Controlled Trial in Comparison to Physical Therapy.

OBJECTIVE: To establish the effects on shoulder biomechanics from a peripheral nerve stimulation (PNS) treatment compared to physical therapy (PT) in stroke survivors with chronic hemiplegic shoulder pain. DESIGN: Single-site, pilot, randomized controlled trial for adults with chronic shoulder pain after stroke. Participants were randomized to receive a 3-week treatment of single-lead PNS or physical therapy (PT). The outcomes included isometric shoulder abduction strength, pain-free shoulder external rotation range of motion (ROM), delay in initiation and termination of shoulder abduction electromyogram (EMG) activity, and the Fugl-Meyer Motor Assessment (upper extremity section). Outcomes were measured at baseline, and at weeks 1, 4, 12, and 16. RESULTS: Twenty-five participants were recruited, 13 to PNS and 12 to PT. There were significant improvements for both PNS and PT in maximum isometric shoulder abduction strength, pain-free external rotation ROM, and Fugl-Meyer Motor Assessment. There were no significant changes in delay of initiation or termination of deltoid EMG with either treatment. CONCLUSIONS: Both PNS and PT are capable of improving shoulder biomechanics in those with HSP, though changes in biomechanics alone do not account for the greater pain relief associated with PNS than PT.

Contralaterally Controlled Functional Electrical Stimulation Improves Hand Dexterity in Chronic Hemiparesis: A Randomized Trial.

BACKGROUND AND PURPOSE: It is unknown whether one method of neuromuscular electrical stimulation for poststroke upper limb rehabilitation is more effective than another. Our aim was to compare the effects of contralaterally controlled functional electrical stimulation (CCFES) with cyclic neuromuscular electrical stimulation (cNMES). METHODS: Stroke patients with chronic (>6 months) moderate to severe upper extremity hemiparesis (n=80) were randomized to receive 10 sessions/wk of CCFES- or cNMES-assisted hand opening exercise at home plus 20 sessions of functional task practice in the laboratory for 12 weeks. The task practice for the CCFES group was stimulation assisted. The primary outcome was change in Box and Block Test (BBT) score at 6 months post treatment. Upper extremity Fugl-Meyer and Arm Motor Abilities Test were also measured. RESULTS: At 6 months post treatment, the CCFES group had greater improvement on the BBT, 4.6 (95% confidence interval [CI], 2.2-7.0), than the cNMES group, 1.8 (95% CI, 0.6-3.0), between-group difference of 2.8 (95% CI, 0.1-5.5), P=0.045. No significant between-group difference was found for the upper extremity Fugl-Meyer (P=0.888) or Arm Motor Abilities Test (P=0.096). Participants who had the largest improvements on BBT were <2 years post stroke with moderate (ie, not severe) hand impairment at baseline. Among these, the 6-month post-treatment BBT gains of the CCFES group, 9.6 (95% CI, 5.6-13.6), were greater than those of the cNMES group, 4.1 (95% CI, 1.7-6.5), between-group difference of 5.5 (95% CI, 0.8-10.2), P=0.023. CONCLUSIONS: CCFES improved hand dexterity more than cNMES in chronic stroke survivors. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00891319.

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.

Neuromuscular Electrical Stimulation for Motor Restoration in Hemiplegia.

This article reviews the most common therapeutic and neuroprosthetic applications of neuromuscular electrical stimulation (NMES) for upper and lower extremity stroke rehabilitation. Fundamental NMES principles and purposes in stroke rehabilitation are explained. NMES modalities used for upper and lower limb rehabilitation are described, and efficacy studies are summarized. The evidence for peripheral and central mechanisms of action is also summarized.

Stroke Rehabilitation Using Virtual Environments.

This review covers the rationale, mechanisms, and availability of commercially available virtual environment-based interventions for stroke rehabilitation. It describes interventions for motor, speech, cognitive, and sensory dysfunction. Also discussed are the important features and mechanisms that allow virtual environments to facilitate motor relearning. A common challenge is the inability to translate success in small trials to efficacy in larger populations. The heterogeneity of stroke pathophysiology has been blamed, and experts advocate for the study of multimodal approaches. Therefore, this article also introduces a framework to help define new therapy combinations that may be necessary to address stroke heterogeneity.

Tailoring Brain Stimulation to the Nature of Rehabilitative Therapies in Stroke: A Conceptual Framework Based on their Unique Mechanisms of Recovery.

Despite showing early promise, several recent clinical trials of noninvasive brain stimulation (NIBS) failed to augment rehabilitative outcomes of the paretic upper limb. This article addresses why pairing NIBS with unilateral approaches is weakly generalizable to patients in all ranges of impairments. The article also addresses whether alternate therapies are better suited for the more impaired patients, where they may be more feasible and offer neurophysiologic advantages not offered with unilateral therapies. The article concludes by providing insight on how to create NIBS paradigms that are tailored to distinctly augment the effects of therapies across patients with varying degrees of impairment.

Control of robotic assistance using poststroke residual voluntary effort.

Poststroke hemiparesis limits the ability to reach, in part due to involuntary muscle co-activation (synergies). Robotic approaches are being developed for both therapeutic benefit and continuous assistance during activities of daily living. Robotic assistance may enable participants to exert less effort, thereby reducing expression of the abnormal co-activation patterns, which could allow participants to reach further. This study evaluated how well participants could perform a reaching task with robotic assistance that was either provided independent of effort in the vertical direction or in the sagittal plane in proportion to voluntary effort estimated from electromyograms (EMG) on the affected side. Participants who could not reach targets without assistance were enabled to reach further with assistance. Constant anti-gravity force assistance that was independent of voluntary effort did not reduce the quality of reach and enabled participants to exert less effort while maintaining different target locations. Force assistance that was proportional to voluntary effort on the affected side enabled participants to exert less effort and could be controlled to successfully reach targets, but participants had increased difficulty maintaining a stable position. These results suggest that residual effort on the affected side can produce an effective command signal for poststroke assistive devices.

Contralaterally controlled functional electrical stimulation for recovery of elbow extension and hand opening after stroke: a pilot case series study.

OBJECTIVE: The aims of this study were to determine whether patients with moderate-to-severe upper limb hemiplegia could use contralaterally controlled functional electrical stimulation at the arm and hand (Arm+Hand CCFES) at home and to evaluate the feasibility of Arm+Hand CCFES to reduce arm and hand motor impairment. DESIGN: With Arm+Hand CCFES, the paretic elbow and hand extensors were stimulated with intensities proportional to the degree of elbow extension and hand opening, respectively, of the contralateral unimpaired side. For 12 wks, four participants with chronic (≥6 mos) upper limb hemiplegia received ∼7 hrs per week of self-administered home-based stimulation-mediated elbow extension and hand opening exercise plus ∼2.5 hrs per week of therapist-supervised laboratory-based stimulation-assisted functional task practice. Assessments of upper limb impairment were made at pretreatment, posttreatment, and 1 mo after treatment. RESULTS: All four participants were able to use the Arm+Hand CCFES system at home either independently or with very minimal assistance from a caregiver. All four participants had increases in the Fugl-Meyer score (1-9 points) and the Wolf Motor Function Test (0.2-0.8 points) and varying degrees of improvement in maximum hand opening, maximum elbow extension, and simultaneous elbow extension and hand opening. CONCLUSIONS: Arm+Hand CCFES can be successfully administered in stroke patients with moderate-to-severe impairment and can reduce various aspects of upper limb impairment. A larger efficacy study is warranted.