[ARTICLE] Arm rehabilitation in post stroke subjects: A randomized controlled trial on the efficacy of myoelectrically driven FES applied in a task-oriented approach – Full Text

Abstract

Purpose

Motor recovery of persons after stroke may be enhanced by a novel approach where residual muscle activity is facilitated by patient-controlled electrical muscle activation. Myoelectric activity from hemiparetic muscles is then used for continuous control of functional electrical stimulation (MeCFES) of same or synergic muscles to promote restoration of movements during task-oriented therapy (TOT). Use of MeCFES during TOT may help to obtain a larger functional and neurological recovery than otherwise possible.

Study design

Multicenter randomized controlled trial.

Methods

Eighty two acute and chronic stroke victims were recruited through the collaborating facilities and after signing an informed consent were randomized to receive either the experimental (MeCFES assisted TOT (M-TOT) or conventional rehabilitation care including TOT (C-TOT). Both groups received 45 minutes of rehabilitation over 25 sessions. Outcomes were Action Research Arm Test (ARAT), Upper Extremity Fugl-Meyer Assessment (FMA-UE) scores and Disability of the Arm Shoulder and Hand questionnaire.

Results

Sixty eight subjects completed the protocol (Mean age 66.2, range 36.5–88.7, onset months 12.7, range 0.8–19.1) of which 45 were seen at follow up 5 weeks later. There were significant improvements in both groups on ARAT (median improvement: MeCFES TOT group 3.0; C-TOT group 2.0) and FMA-UE (median improvement: M-TOT 4.5; C-TOT 3.5). Considering subacute subjects (time since stroke < 6 months), there was a trend for a larger proportion of improved patients in the M-TOT group following rehabilitation (57.9%) than in the C-TOT group (33.2%) (difference in proportion improved 24.7%; 95% CI -4.0; 48.6), though the study did not meet the planned sample size.

Conclusion

This is the first large multicentre RCT to compare MeCFES assisted TOT with conventional care TOT for the upper extremity. No adverse events or negative outcomes were encountered, thus we conclude that MeCFES can be a safe adjunct to rehabilitation that could promote recovery of upper limb function in persons after stroke, particularly when applied in the subacute phase.

 

Introduction

Stroke is the leading cause of disability in adults in the world and can result in highly complex clinical situations. The insult often involves the sensory-motor system leading to hemiparesis and impairment of the upper limb in over 50% of survivors [1,2]. Although some structural recovery is possible, especially in the first months after stroke, only a small percentage of persons recover pre-morbid movement patterns and functionality [3].

Limitations in reaching and grasping have an important role in determining the level of independence of the person in their daily activities and the subsequent impact on their quality of life. Tailored goal oriented rehabilitation is therefore an essential factor in reducing impairment and augmenting functionality of a hemiplegic arm. A plurality of interventions may help the subject to restore participation and adapt to the new clinical status including task oriented therapy (TOT) that has been shown to be effective for motor recovery [4,5], as well as constraint induced movement therapy (CIMT) [6], biofeedback and robot assisted therapy [7–9]. Moreover, electrostimulation has been applied to improve muscle recruitment and aid motor recovery. Since resources and time in rehabilitation are limited it is important to identify and employ effective interventions [10].

The inability to use the arm in an efficient way may lead to non use of the arm and hand that can lead to changes also at the neural level [11]. It is therefore essential that arm use is facilitated in meaningful activities. Approaches that assist the person during purposeful voluntarily activated movement could be important for inducing neuroplasticity and increasing function. Neuromuscular electrical stimulation (NMES) has been employed in rehabilitation of stroke patients either to generate muscle contraction or be a support during movements; however, with inconsistent results [11–20]. A prerequisite for neuroplasticity through training is the volitional intent and attention of the person and it therefore follows that the user should participate consciously in the rehabilitative intervention [21,22].

Through the use of EMG it is technically possible to register the myoelectric activity from voluntary contraction of a muscle while its motor nerve is being stimulated by electrical impulses [23]. MeCFES is a method where the FES is directly controlled by volitional EMG activity. In contrast to EMG triggered FES, the controlling muscle is continuously controlling the stimulation intensity. Thus the resulting movement and intrinsic multisensory activation is synchronized with the active attention and intention of the subject and the muscle contraction can be gradually modulated by the subject himself facilitating motor learning and recovery of function. This has been demonstrated to be possible in spinal cord injured subjects [24,25] and a pilot study has shown that when the controlling and stimulated muscles are homologous or they are synergistic it may lead to a marked increase in motor function of the hemiparetic forearm of selected stroke patients [26]. Motor learning principles required for CNS-activity-dependent plasticity, in fact, include task-oriented movements, muscle activation driving practice of movement, focused attention, repetition of desired movements, and training specificity [21,22,27]. The use of MeCFES during active challenging goal oriented movements should help the patient and the therapist overcome the effect of learned non use by turning attempts to move the arm into successful movements.

We hypothesize that applying MeCFES in a task oriented paradigm to assist normal arm movements during rehabilitation of the upper limb in persons with stroke will improve the movement quality and success and thus induce recovery at the body functions level (impairment) and the activity level (disability) of the International Classification of Function, Disability and Health (ICF) [28] superior to that induced by usual care task-oriented rehabilitation.[…]

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