A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 2: Objective outcomes and patients' perspectives

Motor neuroprosthesis for promoting recovery of function after stroke

BACKGROUND

Motor neuroprosthesis (MN) involves electrical stimulation of neural structures by miniaturized devices to allow the performance of tasks in the natural environment in which people live (home and community context), as an orthosis. In this way, daily use of these devices could act as an environmental facilitator for increasing the activities and participation of people with stroke.

OBJECTIVES

To assess the effects of MN for improving independence in activities of daily living (ADL), activities involving limbs, participation scales of health-related quality of life (HRQoL), exercise capacity, balance, and adverse events in people after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (searched 19 August 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (August 2019), MEDLINE (1946 to 16 August 2019), Embase (1980 to 19 August 2019), and five additional databases. We also searched trial registries, databases, and websites to identify additional relevant published, unpublished, and ongoing trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and randomized controlled cross-over trials comparing MN for improving activities and participation versus other assistive technology device or MN without electrical stimulus (stimulator is turned off), or no treatment, for people after stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted data, and assessed risk of bias of the included studies. Any disagreements were resolved through discussion with a third review author. We contacted trialists for additional information when necessary and performed all analyses using Review Manager 5. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included four RCTs involving a total of 831 participants who were more than three months poststroke. All RCTs were of MN that applied electrical stimuli to the peroneal nerve. All studies included conditioning protocols to adapt participants to MN use, after which participants used MN from up to eight hours per day to all-day use for ambulation in daily activities performed in the home or community context. All studies compared the use of MN versus another assistive device (ankle-foot orthosis [AFO]). There was a high risk of bias for at least one assessed domain in three of the four included studies. No studies reported outcomes related to independence in ADL. There was low-certainty evidence that AFO was more beneficial than MN on activities involving limbs such as walking speed until six months of device use (mean difference (MD) -0.05 m/s, 95% confidence interval (CI) -0.10 to -0.00; P = 0.03; 605 participants; 2 studies; I² = 0%; low-certainty evidence); however, this difference was no longer present in our sensitivity analysis (MD -0.07 m/s, 95% CI -0.16 to 0.02; P = 0.13; 110 participants; 1 study; I² = 0%). There was low to moderate certainty that MN was no more beneficial than AFO on activities involving limbs such as walking speed between 6 and 12 months of device use (MD 0.00 m/s, 95% CI -0.05 to 0.05; P = 0.93; 713 participants; 3 studies; I² = 17%; low-certainty evidence), Timed Up and Go (MD 0.51 s, 95% CI -4.41 to 5.43; P = 0.84; 692 participants; 2 studies; I² = 0%; moderate-certainty evidence), and modified Emory Functional Ambulation Profile (MD 14.77 s, 95% CI -12.52 to 42.06; P = 0.29; 605 participants; 2 studies; I² = 0%; low-certainty evidence). There was no significant difference in walking speed when MN was delivered with surface or implantable electrodes (test for subgroup differences P = 0.09; I² = 65.1%). For our secondary outcomes, there was very low to moderate certainty that MN was no more beneficial than another assistive device for participation scales of HRQoL (standardized mean difference 0.26, 95% CI -0.22 to 0.74; P = 0.28; 632 participants; 3 studies; I² = 77%; very low-certainty evidence), exercise capacity (MD -9.03 m, 95% CI -26.87 to 8.81; P = 0.32; 692 participants; 2 studies; I² = 0%; low-certainty evidence), and balance (MD -0.34, 95% CI -1.96 to 1.28; P = 0.68; 692 participants; 2 studies; I² = 0%; moderate-certainty evidence). Although there was low- to moderate-certainty evidence that the use of MN did not increase the number of serious adverse events related to intervention (risk ratio (RR) 0.35, 95% CI 0.04 to 3.33; P = 0.36; 692 participants; 2 studies; I² = 0%; low-certainty evidence) or number of falls (RR 1.20, 95% CI 0.92 to 1.55; P = 0.08; 802 participants; 3 studies; I² = 33%; moderate-certainty evidence), there was low-certainty evidence that the use of MN in people after stroke may increase the risk of participants dropping out during the intervention (RR 1.48, 95% CI 1.11 to 1.97; P = 0.007; 829 participants; 4 studies; I² = 0%).

AUTHORS' CONCLUSIONS

Current evidence indicates that MN is no more beneficial than another assistive technology device for improving activities involving limbs measured by Timed Up and Go, balance (moderate-certainty evidence), activities involving limbs measured by walking speed and modified Emory Functional Ambulation Profile, exercise capacity (low-certainty evidence), and participation scale of HRQoL (very low-certainty evidence). Evidence was insufficient to estimate the effect of MN on independence in ADL. In comparison to other assistive devices, MN does not appear to increase the number of falls (moderate-certainty evidence) or serious adverse events (low-certainty evidence), but may result in a higher number of dropouts during intervention period (low-certainty evidence).

Self-directed therapy programmes for arm rehabilitation after stroke: a systematic review

AIM

To investigate the effectiveness of self-directed arm interventions in adult stroke survivors.

METHODS

A systematic review of Medline, EMBASE, CINAHL, SCOPUS and IEEE Xplore up to February 2018 was carried out. Studies of stroke arm interventions were included where more than 50% of the time spent in therapy was initiated and carried out by the participant. Quality of the evidence was assessed using the Cochrane risk of bias tool.

RESULTS

A total of 40 studies ( n = 1172 participants) were included (19 randomized controlled trials (RCTs) and 21 before-after studies). Studies were grouped according to no technology or the main additional technology used (no technology n = 5; interactive gaming n = 6; electrical stimulation n = 11; constraint-induced movement therapy n = 6; robotic and dynamic orthotic devices n = 8; mirror therapy n = 1; telerehabilitation n = 2; wearable devices n = 1). A beneficial effect on arm function was found for self-directed interventions using constraint-induced movement therapy ( n = 105; standardized mean difference (SMD) 0.39, 95% confidence interval (CI) -0.00 to 0.78) and electrical stimulation ( n = 94; SMD 0.50, 95% CI 0.08-0.91). Constraint-induced movement therapy and therapy programmes without technology improved independence in activities of daily living. Sensitivity analysis demonstrated arm function benefit for patients >12 months poststroke ( n = 145; SMD 0.52, 95% CI 0.21-0.82) but not at 0-3, 3-6 or 6-12 months.

CONCLUSION

Self-directed interventions can enhance arm recovery after stroke but the effect varies according to the approach used and timing. There were benefits identified from self-directed delivery of constraint-induced movement therapy, electrical stimulation and therapy programmes that increase practice without using additional technology.

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.

The application of precisely controlled functional electrical stimulation to the shoulder, elbow and wrist for upper limb stroke rehabilitation: a feasibility study

Background

Functional electrical stimulation (FES) during repetitive practice of everyday tasks can facilitate recovery of upper limb function following stroke. Reduction in impairment is strongly associated with how closely FES assists performance, with advanced iterative learning control (ILC) technology providing precise upper-limb assistance. The aim of this study is to investigate the feasibility of extending ILC technology to control FES of three muscle groups in the upper limb to facilitate functional motor recovery post-stroke.

Methods

Five stroke participants with established hemiplegia undertook eighteen intervention sessions, each of one hour duration. During each session FES was applied to the anterior deltoid, triceps, and wrist/finger extensors to assist performance of functional tasks with real-objects, including closing a drawer and pressing a light switch. Advanced model-based ILC controllers used kinematic data from previous attempts at each task to update the FES applied to each muscle on the subsequent trial. This produced stimulation profiles that facilitated accurate completion of each task while encouraging voluntary effort by the participant. Kinematic data were collected using a Microsoft Kinect, and mechanical arm support was provided by a SaeboMAS. Participants completed Fugl-Meyer and Action Research Arm Test clinical assessments pre- and post-intervention, as well as FES-unassisted tasks during each intervention session.

Results

Fugl-Meyer and Action Research Arm Test scores both significantly improved from pre- to post-intervention by 4.4 points. Improvements were also found in FES-unassisted performance, and the amount of arm support required to successfully perform the tasks was reduced.

Conclusions

This feasibility study indicates that technology comprising low-cost hardware fused with advanced FES controllers accurately assists upper limb movement and may reduce upper limb impairments following stroke.

Electrical stimulation and iterative learning control for functional recovery in the upper limb post-stroke

Therapies using functional electrical stimulation (FES) in conjunction with practice of everyday tasks have proven effective in facilitating recovery of upper limb function following stroke. The aim of the current study is to develop a multi-channel electrical stimulation system that precisely controls the assistance provided in goal-orientated tasks through use of advanced model-based 'iterative learning control' (ILC) algorithms to facilitate functional motor recovery of the upper limb post-stroke. FES was applied to three muscle groups in the upper limb (the anterior deltoid, triceps and wrist extensors) to assist hemiparetic, chronic stroke participants to perform a series of functional tasks with real objects, including closing a drawer, turning on a light switch and repositioning an object. Position data from the participants' impaired upper limb was collected using a Microsoft Kinect® and was compared to an ideal reference. ILC used data from previous attempts at the task to moderate the FES signals applied to each muscle group on a trial by trial basis to reduce performance error whilst supporting voluntary effort by the participant. The clinical trial is on-going. Preliminary results show improvements in performance accuracy for each muscle group, as well as improvements in clinical outcome measures pre and post 18 training sessions. Thus, the feasibility of applying precisely controlled FES to three muscle groups in the upper limb to facilitate functional reach and grasp movements post stroke has been demonstrated.

A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 1: System architecture

OBJECTIVES

For rehabilitation of the poststroke upper limb in seven subjects, an external sensor-based system controls the timing of five to seven microstimulators implanted near radial nerve branches or their motor points to sequentially extend the elbow, wrist, and fingers with thumb extension and abduction, enabled at the subject's own pace. We hypothesize this system will support sequential activation of affected upper limb muscles intended to improve functional recovery.

MATERIALS AND METHODS

Presented here is a personalized sensor-controlled stimulation system, including its architecture, sensor design, and testing of equipment specific to this study, including coils and sensors.

RESULTS

All electrical and magnetic tests, and safety tests per International Electrotechnical Commission 60601-1 passed. One sensor type displayed a vulnerability to drop.

CONCLUSIONS

The new control system tested safe, met requirements, and allowed each subject to activate the system at their own pace, making the rehabilitation process more acceptable and efficient.