Scholarly article on topic 'A Preliminary Study of Functional Electrical Stimulation in Upper Limb Rehabilitation After Stroke: An Evidence-Based Review'

A Preliminary Study of Functional Electrical Stimulation in Upper Limb Rehabilitation After Stroke: An Evidence-Based Review Academic research paper on "Medical engineering"

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{"Functional electrical stimulation" / "Functional rehabilitation" / "Hemiplegic upper limb" / Stroke}

Abstract of research paper on Medical engineering, author of scientific article — Carol K.L. Chan

Objective To review the effectiveness of functional electrical stimulation (FES) in the rehabilitation of hemiplegic upper limb after stroke. Methods A systematic review of studies published in the recent 5 years from 2003 to 2008, retrieved from MEDLINE and CINAHL, was performed. Results Outcome measures included the Jebsen-Taylor Hand Function Test and wrist range of motion. Results based on five clinical trials reviewed suggest that the use of FES together with functional practice aids the recovery of functional and motor performance in the hemiplegic upper limb. Conclusion FES may be effective as a home-based modality in the rehabilitation of the hemiplegic upper limb after stroke, and is recommended for individuals in the subacute and chronic stages, with residual voluntary wrist and finger movements.

Academic research paper on topic "A Preliminary Study of Functional Electrical Stimulation in Upper Limb Rehabilitation After Stroke: An Evidence-Based Review"

HKJOT 2008;18(2):52-58

A Preliminary Study of Functional Electrical Stimulation in Upper Limb Rehabilitation After Stroke: An Evidence-based Review

Carol K.L. Chan

Objective: To review the effectiveness of functional electrical stimulation (FES) in the rehabilitation of hemiplegic upper limb after stroke.

Methods: A systematic review of studies published in the recent 5 years from 2003 to 2008, retrieved from MEDLINE and CINAHL, was performed.

Results: Outcome measures included the Jebsen-Taylor Hand Function Test and wrist range of motion. Results based on five clinical trials reviewed suggest that the use of FES together with functional practice aids the recovery of functional and motor performance in the hemiplegic upper limb. conclusion: FES may be effective as a home-based modality in the rehabilitation of the hemiplegic upper limb after stroke, and is recommended for individuals in the subacute and chronic stages, with residual voluntary wrist and finger movements.

KEY WORDS: Functional electrical stimulation • Functional rehabilitation • Hemiplegic upper limb • Stroke

Introduction

Residual upper limb (UL) functional deficits are common after stroke, and are found in up to 80% of subacute and 56% of chronic stroke survivors (de Kroon, Ijzerman, Chae, Lankhorst, & Zilvold, 2005; Urton, Kohia, Davis, & Neill, 2007).

Functional electrical stimulation (FES) has been found to be useful in improving components of motor performance in the hemiplegic UL post-stroke, such as motor reaction time, isometric torque, and co-contraction of agonist and antagonist muscles (Pomeroy, King, Pollock, Baily-Hallam, & Langhorne, 2006). Recent findings suggest that FES can also be used as an adjunct to traditional neurological rehabilitation to improve UL and hand function (de Kroon, van der Lee, Ijzerman, & Lankhorst, 2002).

The concept behind FES is to provide functional restoration of the hemiplegic UL following stroke, through electrical

activation of intact lower motor neurons using electrodes on or near innervating nerve fibres (Peckham & Knutson, 2005).

There are three main types of FES. Neuromuscular electrical stimulation (NMES) produces passive repetitive muscle contraction, which the user can attempt to actively and concurrently participate in. Electromyographically-triggered electrical stimulation (EMG-stim) provides electrical stimulation that induces muscle contraction when volitionally generated EMG signals exceed a preset threshold. Positional feedback stimulation training (PFST) works in the same way as EMG-stim, using voluntary joint range of motion (ROM) as the trigger. Transcutaneous electrical nerve stimulation (TENS), commonly used for the treatment of pain, is not considered a type of FES as at low intensities, only sensory reaction is evoked without muscle contraction (de Kroon et al., 2002). FES may be delivered using surface, percutaneous or implanted systems (Peckham & Knutson, 2005). Only NMES,

Department of Rehabilitation, Alexandra Hospital, Singapore.

Reprint requests and correspondence to: K.L. Chan, Occupational Therapist, Department of Rehabilitation, Alexandra Hospital, 378 Alexandra Road, Singapore 159964. E-mail: kar_lock_CHAN@alexhosp.com.sg

Hong Kong Journal of Occupational Therapy ©2008 Elsevier. All rights reserved.

FES IN UPPER LIMB REHABILITATION

EMG-stim and surface systems are included and discussed in this review.

This review aims to determine the effectiveness of FES as a treatment modality in functional and motor rehabilitation of the hemiplegic UL after stroke.

Methods

The Figure summarizes the literature search and recruitment process. A systematic literature search for articles published in the recent 5 years, from January 2003 to February 2008, was performed in MEDLINE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), in order to identify studies in which electrical stimulation was applied with the

intention to improve post-stroke hemiplegic UL function and motor performance. MEDLINE and CINAHL were chosen as they are among the most authoritative and comprehensive databases indexing the professional literature of rehabilitation medicine, occupational therapy and physical therapy.

The following key words were used: "electrical stimulation or FES", "upper limb or upper extremity or hand" and "stroke or CVA or cerebrovascular accident".

Inclusion criteria were: studies published in English; studies involving participants who were at least 3 months post-stroke, to exclude the effects of spontaneous recovery in the acute post-stroke stage; hemiplegic UL function, ROM, tone and/or power/strength as primary outcome measures; and the use of peripheral/surface electrical stimulation.

Figure. Flowchart of literature search and recruitment process. FES =functional electrical stimulation; UL = upper limb. Hong Kong Journal of Occupational Therapy

Carol K.L. Chan

HKJOT2008;18(2)

Studies where the experimental group received electrical stimulation combined with other treatment modalities not received by the control group were excluded. Single case reports, studies investigating pain management, shoulder subluxation and the effects of percutaneous and implanted neuro-prosthetic systems for the hemiplegic UL were also excluded.

The literature search of the two databases yielded 97 articles in total (MEDLINE—55; CINAHL—42); five publications fulfilled all selection criteria.

Results

Details of the included studies are reported in the Table. Characteristics of the Studies

Among the five studies selected for this review, there was one single-group pretest-posttest study; two clinical controlled trials (CCTs); and two randomized controlled trials (RCTs), of which one investigated the effects of crossover to FES treatment for the control group after post-test. Four of the studies implemented FES in a home-based setting.

A total of 168 participants are included in the review. One study recruited participants in the subacute stage of stroke (3-6 months post-stroke), while four studies recruited those in the chronic stage (at least 6 months post-stroke). This was to exclude the effects of spontaneous recovery in the acute stroke stage. All studies recruited participants with some voluntary finger movement in the hemiplegic hand. One study (Ring & Rosenthal, 2005), in addition, included participants with no finger movements. Participants were mostly stroke survivors who had completed formal rehabilitation, and were recruited through rehabilitation centres, support groups and advertisements.

Treatment regimes lasted from 2 to 12 weeks, and the total duration of treatment ranged from 6 to 168 hours. Participants had at least two sessions per week, with three studies having daily sessions. The total duration of treatment received each day were all fairly long, lasting from 60 minutes to 6 hours.

Two studies employed the Automove stimulator (Danmeter A/S, Odense C, Denmark) (Cauraugh & Kim, 2003; Kimberly et al., 2004), which delivered EMG-stim. The other three studies used the commercially available NESS Handmaster™ (Neuromuscular Electrical Stimulation Systems Ltd. [now Bioness Neuromodulation Ltd.], Ra'anana Israel) (Alon & Ring, 2003; Alon, Sunnerhagen, Geurts, & Ohry, 2003; Ring & Rosenthal, 2005), which delivered NMES-type FES. In all three studies using the NESS Handmaster™, treatment was self-administered in the home. Studies using the same device employed similar stimulation parameters. However, between the two groups, stimulation parameters such as frequency (50 Hz vs. 36 Hz),

current type (direct vs. alternating) and rest intervals (25 s vs. 5 s) varied.

The two studies using the Automove stimulator stimulated the wrist and finger extensors, whereas the NESS Handmaster™ studies stimulated the wrist and finger flexors and extensors, as well as the thenar muscles.

The outcome measures for hand function were evaluated using the Box and Blocks (BB) Test, Jebsen-Taylor Hand Function (JT) Test, 9-Hole Peg Test and Motor Activity Log (MAL). Outcome measures for motor performance were: joint ROM; strength (isometric finger extension, sustained muscle contraction); motor reaction time; and tone.

Effect of FES on Hand Function

All five studies reported a significant increase in the number of blocks moved in the BB Test. Apart from the Cauraugh & Kim (2003) study which did not use the JT Test, all the other four studies (Alon & Ring, 2003; Alon et al., 2003; Kimberly et al., 2004; Ring & Rosenthal, 2005) reported a significant reduction in the time required to complete the subcomponents of the JT Test, in comparison with the control groups. In particular, reduction in time required to move a large heavy object in the JT Test was recorded in all four studies.

The MAL measures participants' subjective view of change in amount of use (AOU) and quality of movement (QOM) of the paretic UL. Kimberly et al. (2004) reported an increase in MAL-AOU and MAL-QOM scores in the FES group, as well as in the control group after crossover. No significant differences in MAL-AOU and MAL-QOM scores were found in the control group prior to crossover.

Effect of FES on Motor Performance Only one study, conducted by Ring and Rosenthal (2005), investigated joint ROM as an outcome measure. The authors found that there was a significant increase in wrist and finger extension in the FES group with partial finger/wrist movement. The control groups and the other FES group which did not have residual voluntary finger/wrist movement in the hemiplegic UL did not show significant improvements in joint ROM.

Cauraugh and Kim (2003) reported improvement in motor reaction time, as well as improved sustained muscle contraction only in the FES groups.

One study (Kimberly et al., 2004) measured strength, using index finger isometric contraction. Significant improvement in strength was found in both the FES group and the control group. This was the only incidence within all the studies in which the control group had significant improvement in results comparable to the FES treatment groups.

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Table. Summary of studies investigating use <

r limb (UL) rehabilitation after stroke

Reference Study design (N) Comparison gps Time post-stroke (mean±SD) Treatment regime (wkx sessions/ wk x duration/d) Device applied; target muscles Outcome measures Results (only significant results reported) Remarks

Cauraugh & RCT {N=34) 1. EMG-triggered > 1 yr (3.2 yr) 2 wk x 2 sessions/wk Treatment gp: Hand function Increased no. of No mention if

Kim,2003 NMES (blocked x 90 min Automove EMG BB blocks moved in treatment was

practice) NMES gp: movement facilitator Motor peifonnance BB; improvement in clinic- or

2. EMG-triggered + stimulation stimulator Motor reaction time; motor reaction time; home-based

FES (random Control gp: passive Control gp: nil sustained muscle reduced fluctuation in

practice) range + voluntary EDC, ECU, contraction sustained muscle

3. Control movement triceps brachii. contraction for EMG-

anterior & triggered blocked &

middle deltoid random practice gps

Kimberly Double-blind 1. EMG-triggered >6 mo 60 hr in 3 wk Treatment gp: Hand function • Improved isometric • No instructions

et al., 2004 RCT with NMES (3.0 ±2.1 yr) (3 wk x daily or Automove BB; JT page- IF extension; BB; JT were given to

crossover for 2. Control with alternate AM706 turning/small small obj/stacking/ encourage

control gp sham days x 3-6 hr) Stimulator obj/stacking/ heavy obj; MAL for increased hand

after posttest stimulation Both gps: 50% Control gp: feeding/light treatment gp posttest use or to modify

(N= 16) active effort Automove 700S obj/heavy obj; • Improved isometric behaviour

to trigger response. Wrist & finger MAL; finger IF extension for • Both active

50% automatic extensors movement tracking sham gp posttest (EMG-triggered)

stimulation stimulated Motor peifonnance • Improved isometric & passive

Isometric index IF extension; BB; stimulation

finger extension JT page-turning/ employed

feeding; MAL for • Intensive home-

sham gp based FES

post-crossover

Ring & CCT {N=22) 1. NESS+Rehab 3-6 mo NESS = 6 wk x7dx NESS Hand function • Improved hand • Both gps

Rosenthal, (0 hand) 3 sessions x 50 min Handmaster BB; JT function (BB & JT concurrently

2005 2. NESS+Rehab Rehab = 6 wk x ED, EPB, FDS, feeding/light light obj/heavy obj) received

(S hand) 3 d x 3 hr FPL, thenar obj/heavy obj & wrist flex/ext in functional ADL

3. Rehab (0 hand) muscles Motor peifonnance NESS gp with partial training & NDT

4. Rehab (S hand) Shoulder flex/abd; wrist/hand movement • Home-based use

elbow flex/ext; • Reduced spasticity of NESS

wrist flex/ext; in both NESS gps • Only study that

finger flex/ext; recruited subjects

tone (MAS) with no visible

wrist & finger

movements

(Contd)

Table. (Continued)

Reference Study design (AO Comparison gps Time post-stroke (mean±SD) Treatment regime (wkx sessions/ wk x duration/d) Device applied; target muscles Outcome measures Results (only significant results reported) Remarks

Alon & CCT (N= 19) 1. Stimulated gp >6 mo 12 wk x daily x NESS Handmaster Hand function Greater improvements Home-based.

Ring. 2. Control gp (4.1 ±2.9 yr) 2 sessions x 60 min & circumferential BB; JT in BB & JT feeding/ self-administered

2003 Stimulated gp: device with 4 feeding/light light obj/heavy

self-administered electrodes (for arm) obj/heavy obj obj in stimulated gp

FES with functional ED. EPB. FDS. FPL.

tasks thenar muscles.

Control gp: elbow flexors.

functional training triceps brachii

& self-exercise

Alon. Single-group N/A >6 mo 5 wkx7 sessions/ NESS Handmaster Hand function • Increased no. of blocks Home-based

Sunnerhagen. pretest- (3.3 ± 1.9 yr) wkx2-3 sessions/ ED. EPB. FDS. BB; JT moved in BB (26.3%).

Geurts, & posttest dx 10-55 min FPL. thenar feeding/light Improvements in

Ohry. 2003 (N=11) (daily duration muscles obj/heavy obj; JT timing in

increased 9-Hole Peg Test feeding (34.8%);

gradually) Motor peifonnance light obj (44.9%);

Tone (Ashworth heavy obj (40.9%)

scale) • Improved 9-hole

peg time (58.7%) Reduction in spasticity in elbow (-0.87 pts) & wrist (-0.78 pts)

Study design: CCT = clinical controlled trial; RCT = randomized controlled trial; Comparison gps: 0 hand = partial wrist/finger movement present; H hand = no finger/wrist movement present; Muscles stimulated: ED = extensor digitoram; EPB = extensor pollicis brevis; FDS = flexor digitoram superficialis; FPL = flexor pollicis longus; Outcome measures: BB = Blocks and Box Test; JT = Jebsen-Taylor Hand Function Test; MAL (AS/HW) = Motor Activity Log (amount of use/how well); MAS = Modified Ashworth Scale.

FES IN UPPER LIMB REHABILITATION

Two studies (Alon et al., 2003; Ring & Rosenthal, 2005) investigated the effect of FES on muscle tone and found that spasticity was reduced in the groups who received FES.

None of the studies reported greater improvements in outcome measures in the control groups over the stimulation groups. Of greater note, however, was the finding of improvements in strength and hand function in the control group of the Kimberly et al. (2004) study after crossover to receive FES. This strengthens the unanimous results of all five studies, i.e. that the use of FES improves functional and motor outcomes of the hand.

Discussion

Mechanism of Action

Cauraugh and Kim (2003) proposed that FES decreased the processing time required for stimulus identification and response initiation. Muscular activation patterns improved as a result, leading to improved voluntary initiation of movements in the impaired limb.

FES may help to activate neurons that can orchestrate synergistic control of multiple muscular forces for functional hand movements (Alon & Ring, 2003; Alon et al., 2003; Kimberly et al., 2004; Ring & Rosenthal, 2005). Specifically, activation of both flexors and extensors of the wrist and fingers in a synchronized way resulted in the ability to open and close the hand.

Functional Training

In the two RCTs and two CCTs, all the control groups received functional UL movement training. The treatment groups received similar functional training, in conjunction with FES.

Results of the studies suggest that active stimulation in conjunction with functional practice aids the recovery of function (Cauraugh & Kim, 2003). In one case, study participants using FES were even able to learn new functional tasks (Alon & Ring, 2003).

In contrast, individuals performing functional tasks alone, without FES or with sham stimulation, showed no significant improvement in all functional outcome measures. In the study by Kimberly et al. (2004), the control group which performed voluntary functional movement patterns without FES showed improvements in index finger isometric contraction, but did not improve in functional measures post-treatment. Improvement in strength was attributed to repeated extension of the finger. However, this same control group was found to have improvements in function after crossover to receive FES. This strengthens the conclusion that FES combined with functional training improves function.

Therapists should note that specificity of training (Alon & Ring, 2003) yields more effective and efficient outcomes than training provided in isolation and out of context of functional performance. Thus, FES training provided should be related to the functional task that is being retrained.

Type of Patients Suitable for FES

From the five studies reviewed, FES is suitable for individuals in the subacute and chronic phases of stroke, with mild to moderate severity of hemiplegic UL dysfunction. Individuals should also have at least some visible residual voluntary wrist and finger movements (Alon et al., 2003; Ring & Rosenthal, 2005).

The use of FES is not recommended in subjects with pacemakers, uncontrolled seizure disorders, structural impairment in the hemiparetic UL, severe neglect, severe aphasia and skin problems (Ring & Rosenthal, 2005).

Effect of Treatment Regime Factors Based on the study by Cauraugh and Kim (2003), there appears to be no difference between blocked (same movement repetitively attempted in successive trials) and random (different movements attempted in successive trials) practice. Therefore, therapists need not be overly concerned with the practice schedule for UL movements.

In two of the studies (Alon & Ring, 2003; Cauraugh & Kim, 2003), FES combined with bilateral movements in the unimpaired limb resulted in additional functional motor recovery improvements. There appears to be an advantage in simultaneously initiating the same movement in both limbs.

A previous review by de Kroon et al. (2005) stated that triggered electrical stimulation may be more effective than non-triggered electrical stimulation in facilitating UL recovery. In this review, two studies employed the use of triggered EMG-stim (Cauraugh & Kim, 2003; Kimberly et al., 2004), whereas three studies used non-triggered NMES (Alon & Ring, 2003; Alon et al., 2003; Ring & Rosenthal, 2005). The unanimous outcomes of these five studies, however, suggest that non-triggered FES may be as effective as triggered FES, provided that non-triggered-FES users attempt to concurrently and actively follow through with the movement induced by the passive stimulation, as was done in the studies.

Though the stimulation parameters used in the studies were different, outcomes were all positive. This echoes the proposition by de Kroon et al. (2005) that stimulation parameters may not be crucial in determining motor outcomes.

Use of FES in the Home Setting

The two devices employed in the studies, Automove EMG facilitator stimulator and NESS Handmaster™, were simple,

Carol K.L. Chan

HKJOT2008;18(2)

accurate and comfortable to use (Alon & Ring, 2003; Alon et al., 2003).

Despite the high intensity and long duration of use, high compliance with the FES equipment was recorded (Alon & Ring, 2003; Ring & Rosenthal, 2005).

These factors contributed to the success of self-administered home use, which has benefits over clinic-based treatment. Home-based use of FES allows for long duration (60 minutes to 6 hours) of daily use.

However, the high cost of the NESS Handmaster™ may pose a barrier to more widespread use of this treatment modality.

Adverse Effects

Apart from minor, transient skin irritation mentioned in the study by Alon and Ring (2003), there were no reports of increased limb pain, spasticity or other adverse reactions from the use of FES (Alon & Ring; Ring & Rosenthal, 2005).

Study Strengths and Limitations

The strengths of the five studies include good study design with clear study protocols. All five studies had at least 10 study participants, with one study having a sample size of 77. Even though three studies had fewer than 30 participants, the unanimous outcomes and low drop-out rates add strength to the conclusions drawn.

Two limitations were identified. The long-term sustainability of using FES in the treatment of hemiplegic UL dysfunction post-stroke was not studied. Secondly, there was insufficient evidence on the incorporation of bimanual tasks with FES training to make definite conclusions.

Limitations of Review

The conclusions of this review can only be generalized to individuals in the subacute and chronic stages of stroke, as there were no articles relating to acute stroke included in this review. A more thorough literature search, using additional databases and hand-searching of articles will yield a greater number of studies with good study design, to add more strength to the discussion and conclusions made.

Conclusion

FES is effective as a treatment modality in functional and motor rehabilitation of the hemiplegic UL following stroke,

and is recommended as a home-based treatment modality by occupational therapists for individuals in the subacute and chronic stages of stroke, with at least some visible residual voluntary wrist and finger movements.

Training in the use of FES as a treatment modality in undergraduate occupational therapy programmes is also recommended, to introduce to students an effective and innovative modality which has not been commonly used before, as studies have found that the choice of treatment selected by therapists appears to be determined by the treatment approach that is prevalent during training (Pomeroy et al., 2006).

References

Alon, G., & Ring, H. (2003). Gait and hand function enhancement following training with a multi-segment hybrid-orthosis stimulation system in stroke patients. Journal of Stroke and Cerebrovascular Diseases, 12, 209-216.

Alon, G., Sunnerhagen, K. S., Geurts, A. C. H., & Ohry, A. (2003). A home-based, self-administered stimulation program to improve selected hand functions of chronic stroke. Neurorehabilitation, 18, 215-225.

Cauraugh, J. H., & Kim, S. B. (2003). Stroke motor recovery: Active neuromuscular stimulation and repetitive practice schedules. Journal of Neurology, Neurosurgery, and Psychiatry, 74, 1562-1566.

de Kroon, J. R., Ijzerman, M. J., Chae, J., Lankhorst, G. J., & Zilvold, G. (2005). Relation between stimulation characteristics and clinical outcome in studies using electrical stimulation to improve motor control of the upper extremity in stroke. Journal of Rehabilitation Medicine, 37, 65-74.

de Kroon, J. R., van der Lee, J. H., Ijzerman, M. J., & Lankhorst, G. J. (2002). Therapeutic electrical stimulation to improve motor control and functional abilities of the upper extremity after stroke: A systematic review. Clinical Rehabilitation, 16, 350-360.

Kimberley, T. J., Lewis, S. M., Auerbach, E. J., Dorsey, L. L., Lojovich, J. M., & Carey, J. R. (2004). Electrical stimulation driving functional improvements and cortical changes in subjects with stroke. Experimental Brain Research, 154, 450-460.

Peckham, P. H., & Knutson, J. S. (2005). Functional electrical stimulation for neuromuscular applications. Annual Review of Biomedical Engineering, 7, 327-360.

Pomeroy, V. M., King, L., Pollock, A., Baily-Hallam, A., & Langhorne, P. (2006, April 19). Electrostimulation for promoting recovery of movement or functional ability after stroke. Cochrane Database of Systematic Reviews, (2), Article CD003241. Retrieved February 20, 2008, from The Cochrane Library Database.

Ring, H., & Rosenthal, N. (2005). Controlled study of neuroprosthetic functional electrical stimulation in sub-acute post-stroke rehabilitation. Journal of Rehabilitation Medicine, 37, 32-36.

Urton, M. L., Kohia, M., Davis, J., & Neill, M. R. (2007). Systematic review of treatment interventions for upper extremity hemiparesis following stroke. Occupational Therapy International, 14, 11-27.