Responses of the densely hemiplegic upper extremity to bilateral training

Recovery Potential After Acute Stroke

In acute stroke, the major factor for recovery is the early use of thrombolysis aimed at arterial recanalization and reperfusion of ischemic brain tissue. Subsequently, neurorehabilitative training critically improves clinical recovery due to augmention of postlesional plasticity. Neuroimaging and electrophysiology studies have revealed that the location and volume of the stroke lesion, the affection of nerve fiber tracts, as well as functional and structural changes in the perilesional tissue and in large-scale bihemispheric networks are relevant biomarkers of post-stroke recovery. However, associated disorders, such as mood disorders, epilepsy, and neurodegenerative diseases, may induce secondary cerebral changes or aggravate the functional deficits and, thereby, compromise the potential for recovery.

Simulation of Bilateral Movement Training Through Mirror Reflection: A Case Report Demonstrating an Occupational Therapy Technique for Hemiparesis

In rehabilitation for hemiparesis, one of the goals of an occupational therapist is to practice upper extremity tasks with the recovering individual. The practice is intended to strengthen muscles and refine movements. It also provides examples for the recovering body and brain as they attempt to reestablish the now delicate cognitive and neural connections mediating voluntary behavior. However, the paresis significantly limits the movement sequence possibilities that may be physically practiced. We outline a method for using simulation of movement, which is intended to provide a means for experiencing a range of smooth and controlled movements completed by a paretic limb. The simulation provides a compelling perceptual experience of bilateral motion beyond the current capabilities of the affected limb. The benefits of this technique after a 3-week course of the simulation practice are exemplified by the presented case study that reveals improved function as demonstrated by increases in Fugl-Meyer scores and faster movement speeds as demonstrated by decreased movement times for the Jebsen test of hand function.

What is the evidence for physical therapy poststroke? A systematic review and meta-analysis

BACKGROUND

Physical therapy (PT) is one of the key disciplines in interdisciplinary stroke rehabilitation. The aim of this systematic review was to provide an update of the evidence for stroke rehabilitation interventions in the domain of PT.

METHODS AND FINDINGS

Randomized controlled trials (RCTs) regarding PT in stroke rehabilitation were retrieved through a systematic search. Outcomes were classified according to the ICF. RCTs with a low risk of bias were quantitatively analyzed. Differences between phases poststroke were explored in subgroup analyses. A best evidence synthesis was performed for neurological treatment approaches. The search yielded 467 RCTs (N = 25373; median PEDro score 6 [IQR 5-7]), identifying 53 interventions. No adverse events were reported. Strong evidence was found for significant positive effects of 13 interventions related to gait, 11 interventions related to arm-hand activities, 1 intervention for ADL, and 3 interventions for physical fitness. Summary Effect Sizes (SESs) ranged from 0.17 (95%CI 0.03-0.70; I(2) = 0%) for therapeutic positioning of the paretic arm to 2.47 (95%CI 0.84-4.11; I(2) = 77%) for training of sitting balance. There is strong evidence that a higher dose of practice is better, with SESs ranging from 0.21 (95%CI 0.02-0.39; I(2) = 6%) for motor function of the paretic arm to 0.61 (95%CI 0.41-0.82; I(2) = 41%) for muscle strength of the paretic leg. Subgroup analyses yielded significant differences with respect to timing poststroke for 10 interventions. Neurological treatment approaches to training of body functions and activities showed equal or unfavorable effects when compared to other training interventions. Main limitations of the present review are not using individual patient data for meta-analyses and absence of correction for multiple testing.

CONCLUSIONS

There is strong evidence for PT interventions favoring intensive high repetitive task-oriented and task-specific training in all phases poststroke. Effects are mostly restricted to the actually trained functions and activities. Suggestions for prioritizing PT stroke research are given.

Bilateral Priming Accelerates Recovery of Upper Limb Function After Stroke

Background and Purpose—

The ability to live independently after stroke depends on the recovery of upper limb function. We hypothesized that bilateral priming with active–passive movements before upper limb physiotherapy would promote rebalancing of corticomotor excitability and would accelerate upper limb recovery at the subacute stage.

Methods—

A single-center randomized controlled trial of bilateral priming was conducted with 57 patients randomized at the subacute stage after first-ever ischemic stroke. The PRIMED group made device-assisted mirror symmetrical bimanual movements before upper limb physiotherapy, every weekday for 4 weeks. The CONTROL group was given intermittent cutaneous electric stimulation of the paretic forearm before physiotherapy. Assessments were made at baseline, 6, 12, and 26 weeks. The primary end point was the proportion of patients who reached their plateau for upper limb function at 12 weeks, measured with the Action Research Arm Test.

Results—

Odds ratios indicated that PRIMED participants were 3× more likely than controls to reach their recovery plateau by 12 weeks. Intention-to-treat and per-protocol analyses showed a greater proportion of PRIMED participants achieved their plateau by 12 weeks (intention to treat, χ 2 =4.25; P =0.039 and per protocol, χ 2 =3.99; P =0.046). ANOVA of per-protocol data showed PRIMED participants had greater rebalancing of corticomotor excitability than controls at 12 and 26 weeks and interhemispheric inhibition at 26 weeks (all P <0.05).

Conclusions—

Bilateral priming accelerated recovery of upper limb function in the initial weeks after stroke.

Clinical Trial Registration—

URL: http://www.anzctr.org.au . Unique identifier: ANZCTR1260900046822.

Insights into upper limb kinematics and trunk control one year after task-related training in chronic post-stroke individuals

STUDY DESIGN

Randomized clinical trial.

INTRODUCTION

Long-term follow-up of training investigations involving post-stroke individuals can lead to advancing clinical decisions. Extended task-related training (TRT) effects on reaching with the impaired upper limb were evaluated, using a pre-test/posttest/follow-up design.

PURPOSE

One-year follow-up examinations analyzed whether improved shoulder and elbow motion were maintained following prolonged practice of the upper limb.

METHODS

Long-term kinematic analysis on 21 moderately impaired post-stroke participants (upper extremity Fugl-Meyer between 19 and 40/66), as well as results from standardized outcome measures performed on these patients and another 16 post-stroke participants.

RESULTS

Significant initial changes were maintained for kinematic shoulder and elbow motion, as well as functional measures. Compensatory reaching involving the trunk has been shown to be maintainable, but ultimately less efficient.

CONCLUSIONS

Training that involves a conscious decision to control the trunk led to the most improved functional performance, and may lead to ideal restorative strategies.

LEVEL OF EVIDENCE

2B.

Mirror versus parallel bimanual reaching

Background

In spite of their importance to everyday function, tasks that require both hands to work together such as lifting and carrying large objects have not been well studied and the full potential of how new technology might facilitate recovery remains unknown.

Methods

To help identify the best modes for self-teleoperated bimanual training, we used an advanced haptic/graphic environment to compare several modes of practice. In a 2-by-2 study, we compared mirror vs. parallel reaching movements, and also compared veridical display to one that transforms the right hand’s cursor to the opposite side, reducing the area that the visual system has to monitor. Twenty healthy, right-handed subjects (5 in each group) practiced 200 movements. We hypothesized that parallel reaching movements would be the best performing, and attending to one visual area would reduce the task difficulty.

Results

The two-way comparison revealed that mirror movement times took an average 1.24 s longer to complete than parallel. Surprisingly, subjects’ movement times moving to one target (attending to one visual area) also took an average of 1.66 s longer than subjects moving to two targets. For both hands, there was also a significant interaction effect, revealing the lowest errors for parallel movements moving to two targets (p < 0.001). This was the only group that began and maintained low errors throughout training.

Conclusion

Combined with other evidence, these results suggest that the most intuitive reaching performance can be observed with parallel movements with a veridical display (moving to two separate targets). These results point to the expected levels of challenge for these bimanual training modes, which could be used to advise therapy choices in self-neurorehabilitation.

Randomized trial of distributed constraint-induced therapy versus bilateral arm training for the rehabilitation of upper-limb motor control and function after stroke

BACKGROUND AND OBJECTIVE

This study compared the efficacy of distributed constraint-induced therapy (dCIT), bilateral arm training (BAT), and control treatment (CT) on motor control and functional performance of the upper limb in stroke patients.

METHODS

A total of 66 patients with mean stroke onset of 16.20 months and mild to moderate motor impairment were randomized to dCIT, BAT, or CT groups. Each group received treatment for 2 h/d and 5 d/wk for 3 weeks. Pretreatment and posttreatment measures included reaching kinematic variables in unilateral and bilateral tasks, the Wolf Motor Function Test (WMFT), and the Motor Activity Log (MAL).

RESULTS

The dCIT and BAT groups had smoother reaching trajectories in the unilateral and bilateral tasks than the CT group. The BAT group, but not the dCIT group, generated greater force at movement initiation than the CT group during the unilateral and bilateral tasks. The dCIT patients had decreased WMFT time and higher functional ability scores than the CT patients. MAL results pointed to better performance in the amount and quality of use of the affected arm than BAT and CT patients.

CONCLUSIONS

BAT and dCIT exhibited similar beneficial effects on movement smoothness but differential effects on force at movement initiation and functional performance. Therefore, BAT is a better option if improvement of force generation is the treatment goal, and dCIT is more appropriate for improving functional ability and use of the affected arm in daily life. These findings may assist in the planning of individually tailored rehabilitation therapies.

Bilateral and unilateral arm training improve motor function through differing neuroplastic mechanisms: a single-blinded randomized controlled trial

BACKGROUND AND PURPOSE

This randomized controlled trial tests the efficacy of bilateral arm training with rhythmic auditory cueing (BATRAC) versus dose-matched therapeutic exercises (DMTEs) on upper-extremity (UE) function in stroke survivors and uses functional magnetic resonance imaging (fMRI) to examine effects on cortical reorganization.

METHODS

A total of 111 adults with chronic UE paresis were randomized to 6 weeks (3×/week) of BATRAC or DMTE. Primary end points of UE assessments of Fugl-Meyer UE Test (FM) and modified Wolf Motor Function Test Time (WT) were performed 6 weeks prior to and at baseline, after training, and 4 months later. Pretraining and posttraining, fMRI for UE movement was evaluated in 17 BATRAC and 21 DMTE participants.

RESULTS

The improvements in UE function (BATRAC: FM Δ = 1.1 + 0.5, P = .03; WT Δ = -2.6 + 0.8, P < .00; DMTE: FM Δ = 1.9 + 0.4, P < .00; WT Δ = -1.6 + 0.7; P = .04) were comparable between groups and retained after 4 months. Satisfaction was higher after BATRAC than DMTE (P = .003). BATRAC led to significantly higher increase in activation in ipsilesional precentral, anterior cingulate and postcentral gyri, and supplementary motor area and contralesional superior frontal gyrus (P < .05). Activation change in the latter was correlated with improvement in the WMFT (P = .01).

CONCLUSIONS

BATRAC is not superior to DMTE, but both rehabilitation programs durably improve motor function for individuals with chronic UE hemiparesis and with varied deficit severity. Adaptations in brain activation are greater after BATRAC than DMTE, suggesting that given similar benefits to motor function, these therapies operate through different mechanisms.

The influence of two rehabilitation protocols in upper-limb function of stroke patients

Aims

A significant decrease in upper-limb functionality occurs after stroke. There are two different approaches to the upper-limb rehabilitation of stroke patients: unilateral and bilateral protocols. The main aim of this study was to assess the differences in the functionality of the hemiparetic upper-limb between individuals with chronic hemiparesis submitted to a unilateral protocol and those submitted to a bilateral protocol.

Methods

Eight individuals with stroke and chronic hemiparesis were recruited and randomly assigned to one of two groups (four participants in each group). All participants were observed over a period of six weeks, and were evaluated at four different moments of the intervention protocol using the Fulg-Meyer Assessment Scale (FM) (Fulg-Meyer et al, 1975) and the Purdue Pegboard (PP) (Tiffin, 1948). The statistical procedures included percentage evolution and descriptive analysis for each participant.

Findings

The findings suggest that the unilateral protocol provides better results, when compared with the bilateral protocol.

Conclusions

This study suggests that unilateral protocols are at least as effective as bilateral protocols for hemiparetic upper-limb rehabilitation.

Simultaneous bilateral training for improving arm function after stroke

BACKGROUND

Simultaneous bilateral training, the completion of identical activities with both arms simultaneously, is one intervention to improve arm function and reduce impairment.

OBJECTIVES

To determine the effects of simultaneous bilateral training for improving arm function after stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Trials Register (last searched August 2009) and 10 electronic bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2009), MEDLINE, EMBASE, CINAHL and AMED (August 2009). We also searched reference lists and trials registers.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention was simultaneous bilateral training compared to placebo or no intervention, usual care or other upper limb (arm) interventions. PRIMARY OUTCOMES were performance in activities of daily living (ADL) and functional movement of the upper limb. SECONDARY OUTCOMES were performance in extended activities of daily living and motor impairment of the arm.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts, extracted data and appraised trials. Assessment of methodological quality was undertaken for allocation concealment, blinding of outcome assessor, intention-to-treat, baseline similarity and loss to follow up.

MAIN RESULTS

We included 18 studies involving 549 relevant participants, of which 14 (421 participants) were included in the analysis (one within both comparisons). Four of the 14 studies compared the effects of bilateral training with usual care.

PRIMARY OUTCOMES

results were not statistically significant for performance in ADL (standardised mean difference (SMD) 0.25, 95% confidence interval (CI) -0.14 to 0.63); functional movement of the arm (SMD -0.07, 95% CI -0.42 to 0.28) or hand (SMD -0.04, 95% CI -0.50 to 0.42).

SECONDARY OUTCOMES

no statistically significant results. Eleven of the 14 studies compared the effects of bilateral training with other specific upper limb (arm) interventions.

PRIMARY OUTCOMES

no statistically significant results for performance of ADL (SMD -0.25, 95% CI -0.57 to 0.08); functional movement of the arm (SMD -0.20, 95% CI -0.49 to 0.09) or hand (SMD -0.21, 95% CI -0.51 to 0.09).

SECONDARY OUTCOMES

one study reported a statistically significant result in favour of another upper limb intervention for performance in extended ADL. No statistically significant differences were found for motor impairment outcomes.

AUTHORS' CONCLUSIONS

There is insufficient good quality evidence to make recommendations about the relative effect of simultaneous bilateral training compared to placebo, no intervention or usual care. We identified evidence that suggests that bilateral training may be no more (or less) effective than usual care or other upper limb interventions for performance in ADL, functional movement of the upper limb or motor impairment outcomes.

Bilateral movement therapy post-stroke: underlying mechanisms and review

Aims

Up to 66% of individuals with stroke never regain functional use of their upper extremities. Bilateral movement training (BMT) is a task-specific rehabilitation technique that has recently been investigated for its influence on upper extremity recovery in individuals post-stroke. BMT is thought to affect the hemiparetic upper extremity by a phenomenon referred to as cross education, or the cross transfer effect.

Methods

This article reviews the theoretical accounts underlying the cross transfer effect and explain the means by which BMT may facilitate recovery of function in the hemiparetic arm. The current research evidence supporting the use of BMT as a therapeutic approach to stroke rehabilitation is discussed, and implications for clinical practice and recommendations for further research are presented.

Findings

Evidence is emerging that BMT improves impairments and function in people with hemiparesis after stroke. The main limitations of existing research on BMT include small sample sizes, varying initial impairment levels, and lack of control groups.

Conclusions

Future research needs to establish which individuals are most likely to benefi tfrom BMT, as well as the optimal dose of BMT, and whether BMT can be used as an adjunct to existing rehabilitation approaches for upper extremity rehabilitation.

Bilateral movement training and stroke motor recovery progress: a structured review and meta-analysis

The purpose was to conduct a structured review and meta-analysis to determine the cumulative effect of bilateral arm training on motor capabilities post stroke. Forty-eight stroke studies were selected from three databases with 25 comparisons qualifying for inclusion in our meta-analysis. We identified and coded four types of bilateral arm interventions with 366 stroke patients. A random effects model using the standardized mean difference technique determined a large and significant effect size (0.734; SE=0.125), high fail-safe N (532), and medium variability in the studies (I(2)=63%). Moderator variable analysis on the type of bilateral training revealed two large and significant effects: (a) BATRAC (0.842; SE=0.155) and (b) coupled bilateral and EMG-triggered neuromuscular stimulation (1.142; SE=0.176). These novel findings provide strong evidence supporting bilateral arm training with the caveat that two coupled protocols, rhythmic alternating movements and active stimulation, are most effective.

Comparing unilateral and bilateral upper limb training: the ULTRA-stroke program design

Background

About 80% of all stroke survivors have an upper limb paresis immediately after stroke, only about a third of whom (30 to 40%) regain some dexterity within six months following conventional treatment programs. Of late, however, two recently developed interventions - constraint-induced movement therapy (CIMT) and bilateral arm training with rhythmic auditory cueing (BATRAC) - have shown promising results in the treatment of upper limb paresis in chronic stroke patients. The ULTRA-stroke (acronym for Upper Limb TRaining After stroke) program was conceived to assess the effectiveness of these interventions in subacute stroke patients and to examine how the observed changes in sensori-motor functioning relate to changes in stroke recovery mechanisms associated with peripheral stiffness, interlimb interactions, and cortical inter- and intrahemispheric networks. The present paper describes the design of this single-blinded randomized clinical trial (RCT), which has recently started and will take several years to complete.

Methods/Design

Sixty patients with a first ever stroke will be recruited. Patients will be stratified in terms of their remaining motor ability at the distal part of the arm (i.e., wrist and finger movements) and randomized over three intervention groups receiving modified CIMT, modified BATRAC, or an equally intensive (i.e., dose-matched) conventional treatment program for 6 weeks. Primary outcome variable is the score on the Action Research Arm test (ARAT), which will be assessed before, directly after, and 6 weeks after the intervention. During those test sessions all patients will also undergo measurements aimed at investigating the associated recovery mechanisms using haptic robots and magneto-encephalography (MEG).

Discussion

ULTRA-stroke is a 3-year translational research program which aims (1) to assess the relative effectiveness of the three interventions, on a group level but also as a function of patient characteristics, and (2) to delineate the functional and neurophysiological changes that are induced by those interventions.

The outcome on the ARAT together with information about changes in the associated mechanisms will provide a better understanding of how specific therapies influence neurobiological changes, and which post-stroke conditions lend themselves to specific treatments.

Trial Registration

The ULTRA-stroke program is registered at the Netherlands Trial Register (NTR, http://www.trialregister.nl, number NTR1665).

The effects of bilateral arm training on motor control and functional performance in chronic stroke: a randomized controlled study

BACKGROUND

Most studies of bilateral arm training (BAT) did not employ a randomized controlled trial design and involved very limited functional training tasks.

OBJECTIVE

Compare the effects of BAT with control intervention (CI) on motor control and motor performance of the upper extremity and also functional gains in patients with chronic stroke.

METHODS

. This 2-group randomized controlled trial with pretreatment and posttreatment measures enrolled 33 stroke patients (mean age = 53.85 years) 6 to 67 months after onset of a first stroke. They received either a BAT program concentrating on both upper extremities moving simultaneously in functional tasks by symmetric patterns or CI (control treatment) for 2 hours on weekdays for 3 weeks. Outcome measures included kinematic analyses assessing motor control strategies for unilateral and bimanual reaching and clinical measures involving the Fugl-Meyer Assessment (FMA) of motor-impairment severity and the Functional Independence Measure (FIM) and the Motor Activity Log (MAL) evaluating functional ability.

RESULTS

After treatment, the BAT group showed better temporal and spatial efficiency during unilateral and bilateral tasks and less online error correction only during the bilateral task than the control group. The BAT group showed a significantly greater improvement in the FMA than the control group but not in the FIM and MAL.

CONCLUSIONS

Relative to CI, BAT improved the spatiotemporal control of the affected arm in both bilateral and unilateral tasks, decreased online corrections to perform bilateral tasks, and reduced motor impairment. These findings support the use of BAT to improve motor control and motor function of the affected upper limb in stroke patients.

Effect of bilateral reaching on affected arm motor control in stroke – with and without loading on unaffected arm

PURPOSE

To investigate the effect of bilateral reaching, with/without inertial loading on the unaffected arm, on hemiparetic arm motor control in stroke.

METHODS

Twenty unilateral stroke patients were recruited. A three-dimensional optical motion capture system was used to measure the movement trajectory of the hemiparetic arm while performing three tasks: affected limb reaching forward; two-limb reaching forward; and two-limb reaching forward with inertia loading of 25% upper limb weight on the unaffected limb, respectively. Kinematical parameters were utilized to quantify the reaching performance of the affected arm.

RESULTS

No matter whether loading was applied on the unaffected arm or not, the bilateral reaching task did not significantly facilitate smoother and faster movement. Furthermore, during bilateral reaching task with/without loading on the unaffected arm, stroke patients showed slower movement, lower maximal movement velocity, feedback control dominant and discontinuous movements in the affected arm than the same task with unilateral reaching. Subjects showed the greatest active upper extremity range of motion in proximal joints during the bilateral reaching task without unaffected arm loading. The amount of trunk movement also increased during bilateral reaching either with or without loading on the unaffected arm. Patients with moderate upper extremity motor impairment performed more discontinuous movements and less active elbow range of motion during bilateral reaching tasks; however, those with mild upper extremity motor impairment performed smoother movements and demonstrated greater active elbow range of motion during bilateral reaching tasks.

CONCLUSIONS

Bilateral reaching tasks with/without loading on the unaffected arm could be considered as adding challenges during motor control training. Training with bilateral arm movements may be considered as a treatment strategy, and can be incorporated in stroke rehabilitation to facilitate greater arm active movement and improve motor control performance in the affected arm.

Using non-invasive brain stimulation to augment motor training-induced plasticity

Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation of plastic changes in the brain. Therefore, adjunct interventions that can augment the response of the motor system to the behavioural training might be useful to enhance the therapy-induced recovery in neurological populations. In this context, noninvasive brain stimulation appears to be an interesting option as an add-on intervention to standard physical therapies. Two non-invasive methods of inducing electrical currents into the brain have proved to be promising for inducing long-lasting plastic changes in motor systems: transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). These techniques represent powerful methods for priming cortical excitability for a subsequent motor task, demand, or stimulation. Thus, their mutual use can optimize the plastic changes induced by motor practice, leading to more remarkable and outlasting clinical gains in rehabilitation. In this review we discuss how these techniques can enhance the effects of a behavioural intervention and the clinical evidence to date.

Effects of Constraint-Induced Therapy Versus Bilateral Arm Training on Motor Performance, Daily Functions, and Quality of Life in Stroke Survivors

Background and Objective. This study investigated the relative effects of distributed constraint-induced therapy (CIT) and bilateral arm training (BAT) on motor performance, daily function, functional use of the affected arm, and quality of life in patients with hemiparetic stroke. Methods. A total of 60 patients were randomized to distributed CIT, BAT, or a control intervention of less specific but active therapy. Each group received intensive training for 2 hours/day, 5 days/week, for 3 weeks. Pretreatment and posttreatment measures included the Fugl—Meyer Assessment (FMA), Functional Independence Measure (FIM), Motor Activity Log (MAL), and Stroke Impact Scale (SIS). The proximal and distal scores of FMA were used to examine separate upper limb (UL) elements of movement. Results . The distributed CIT and BAT groups showed better performance in the overall and the distal part score of the FMA than the control group. The BAT group exhibited greater gains in the proximal part score of the FMA than the distributed CIT and control groups. Enhanced performance was found for the distributed CIT group in the MAL, the subtest of locomotion in the FIM, and certain domains of the SIS (eg, ADL/IADL). Conclusion. BAT may uniquely improve proximal UL motor impairment. In contrast, distributed CIT may produce greater functional gains for the affected UL in subjects with mild to moderate chronic hemiparesis.

Priming the motor system enhances the effects of upper limb therapy in chronic stroke

After stroke, the function of primary motor cortex (M1) between the hemispheres may become unbalanced. Techniques that promote a re-balancing of M1 excitability may prime the brain to be more responsive to rehabilitation therapies and lead to improved functional outcomes. The present study examined the effects of Active-Passive Bilateral Therapy (APBT), a putative movement-based priming strategy designed to reduce intracortical inhibition and increase excitability within the ipsilesional M1. Thirty-two patients with upper limb weakness at least 6 months after stroke were randomized to a 1-month intervention of self-directed motor practice with their affected upper limb (control group) or to APBT for 10-15 min prior to the same motor practice (APBT group). A blinded clinical rater assessed upper limb function at baseline, and immediately and 1 month after the intervention. Transcranial magnetic stimulation was used to assess M1 excitability. Immediately after the intervention, motor function of the affected upper limb improved in both groups (P < 0.005). One month after the intervention, the APBT group had better upper limb motor function than control patients (P < 0.05). The APBT group had increased ipsilesional M1 excitability (P < 0.025), increased transcallosal inhibition from ipsilesional to contralesional M1 (P < 0.01) and increased intracortical inhibition within contralesional M1 (P < 0.005). None of these changes were found in the control group. APBT produced sustained improvements in upper limb motor function in chronic stroke patients and induced specific and sustained changes in motor cortex inhibitory function. We speculate that APBT may have facilitated plastic reorganization in the brain in response to motor therapy. The utility of APBT as an adjuvant to physical therapy warrants further consideration.

Bilateral movement training and stroke rehabilitation: A systematic review and meta-analysis

OBJECTIVE AND DESIGN

Bilateral movement training is being increasingly used as a post-stroke motor rehabilitation protocol. The contemporary emphasis on evidence-based medicine warrants a prospective meta-analysis to determine the overall effectiveness of rehabilitating with bilateral movements.

METHODS

After searching reference lists of bilateral motor recovery articles as well as PubMed and Cochrane databases, 11 stroke rehabilitation studies qualified for this systematic review. An essential requirement for inclusion was that the bilateral training protocols involved either functional tasks or repetitive arm movements. Each study had one of three common arm and hand functional outcome measures: Fugl-Meyer, Box and Block, and kinematic performance.

RESULTS

The fixed effects model primary meta-analysis revealed an overall effect size (ES=0.732, S.D.=0.13). These findings indicate that bilateral movement training was beneficial for improving motor recovery post-stroke. Moreover, a fail-safe analysis indicated that 48 null effects would be necessary to lower the mean effect size to an insignificant level.

CONCLUSION

These meta-analysis findings indicate that bilateral movements alone or in combination with auxiliary sensory feedback are effective stroke rehabilitation protocols during the sub-acute and chronic phases of recovery.

Exploiting interlimb coupling to improve paretic arm reaching performance in people with chronic stroke

OBJECTIVE

To determine whether paretic arm reaching performance is improved in bilateral compared with unilateral conditions.

DESIGN

Cohort study.

SETTING

University human performance laboratory.

PARTICIPANTS

Thirty-two subjects with chronic stroke (57+/-14y; on Fugl-Meyer Assessment arm score, 37+/-14).

INTERVENTION

Unilateral and bilateral reaching. Bilateral tasks included varying levels of weight on the nonparetic hand.

MAIN OUTCOME MEASURES

An electromagnetic tracking system recorded hand peak acceleration, velocity, and movement time. A 2-way repeated-measures analysis of variance and Tukey-adjusted pairwise comparisons were used to analyze the results (alpha=.05).

RESULTS

Paretic differed significantly from nonparetic peak acceleration and velocity in unilateral reaching but not bilateral reaching. Within limbs, the paretic arm attained a higher peak acceleration (P<.001) and velocity (P=.03) in the bilateral compared with the unilateral task, but movement time was unchanged between tasks. Nonparetic peak acceleration was higher (P=.015), velocity was unchanged, and movement time increased (P=.005) in the bilateral compared with the unilateral task. The addition of a weight to the nonparetic arm during bilateral reaching did not result in further improvement in paretic arm performance.

CONCLUSIONS

Interlimb coupling effects during bilateral reaching are retained even after chronic stroke and can be used to produce an immediate improvement in paretic arm reaching performance.

Impact of peripheral nerve injury on sensorimotor control

Deficits in sensorimotor control are experienced immediately after nerve injury due to changes in the periphery and central nervous system. Muscle denervation and sensory loss often disrupt prehensile coordination requiring the use of alternative strategies. To effectively foster coordination postinjury clinicians should address not only impairments and function but motor control issues through the prescription of specific sensory and motor experiences. Engagement in carefully planned, therapeutic activity can take advantage of the nervous systems' ability to regenerate and reorganize following nerve lesions. This article reviews motor control issues and neural reorganization concepts that may influence the recovery of skilled prehension following upper limb nerve injury. It also provides clinical guidelines for examining and enhancing coordination.

Neural plasticity and bilateral movements: A rehabilitation approach for chronic stroke

Stroke interferes with voluntary control of motor actions. Although spontaneous recovery of function can occur, restoration of normal motor function in the hemiplegic upper limb is noted in fewer than 15% of individuals. However, there is increasing evidence to suggest that in addition to injury-related reorganization, motor cortex functions can be altered by individual motor experiences. Such neural plasticity has major implications for the type of rehabilitative training administered post-stroke. This review proposes that noteworthy upper extremity gains toward motor recovery evolve from activity-dependent intervention based on theoretical motor control constructs and interlimb coordination principles. Founded on behavioral and neurophysiological mechanisms, bilateral movement training/practice has shown great promise in expediting progress toward chronic stroke recovery in the upper extremity. Planning and executing bilateral movements post-stroke may facilitate cortical neural plasticity by three mechanisms: (a) motor cortex disinhibition that allows increased use of the spared pathways of the damaged hemisphere, (b) increased recruitment of the ipsilateral pathways from the contralesional or contralateral hemisphere to supplement the damaged crossed corticospinal pathways, and (c) upregulation of descending premotorneuron commands onto propriospinal neurons.

Stroke

The search for evidence-based treatments has resulted in an exciting new era for neurorehabilitation intervention strategies for stroke. Although stroke rehabilitation research poses many methodologic challenges, evaluation of stroke rehabilitation interventions is clearly moving beyond descriptive and observational studies toward well designed randomized clinical trials. The goals of this article are to summarize issues of trial design for stroke rehabilitation, to discuss promising stroke rehabilitation treatments currently undergoing rigorous evaluation, and to present treatments that may be candidates for randomized clinical trials in the future on the basis of promising preliminary data. Several examples of new developments in neuroscience research that are leading to possible rehabilitation interventions will be discussed. New modalities to evaluate the response of neural networks to rehabilitation interventions are also reviewed.