Hand dexterity rehabilitation using selective functional electrical stimulation in a person with stroke

Abstract

We report a 69 year old who suffered a cardioembolic ischaemic stroke on 23 September 2019, which resulted in a left hemiplegia with motor impairment in upper and lower extremities that made impossible for her to use the affected arm in daily living activities. The person commenced her comprehensive physiotherapy programme based on functional electrical stimulation (FES) in Fesia Clinic rehabilitation centre in October 2020. A multifield technology-based FES device was used, which allowed to train different selective movements in isolation and combined with mirror therapy, achieving excellent functional outcomes.

Background

One of the most common sequelae after a stroke is the limitation or loss of functional capacity of the upper and lower extremities. In the case of the upper limbs, most stroke survivors present a significant loss of arm function, being the most common chronic sequela in this pathology.¹ In fact, 65% of people are unable to use their affected hand in daily living activities 6 months after stroke.² This loss of functionality affects the quality of life, making them, in many cases, dependent.³ The wrist and hand finger extensions are most commonly affected movements, being difficult to recover completely. Finally, it should be noted that, to date, only 10% of severely affected persons recover hand functionality.⁴

Functional electrical stimulation (FES) is one of the options for treating hand dexterity after stroke, and it consists in providing short bursts of electrical pulses to induce action potentials in muscles; producing contractions; and, thus, restoring motor function.⁵ FES-based devices used for hand rehabilitation stimulate the forearm muscles to ensure the movements of the wrist and fingers joints. Its use is widely supported by the scientific evidence, having shown improvements in functional,⁶ biomechanical⁷ and neurophysiological terms.⁸ Some of the most important findings that have been made in clinical trials are the improvement of the motor function (increase of up to 48% in the Box and Block Test⁹ and up to 27.2 points in the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE)),¹⁰ the increase of the latencies and amplitudes of the motor-evoked potentials and the excitability of the corticospinal tract,⁸ the improvement in the performance of the activities of daily living¹¹ or the decrease of spasticity (up to 56% in the wrist and finger flexor muscles),¹² after a FES-based motor rehabilitation intervention.

Traditionally, FES devices have been based on conventional electrodes. However, surface multifield electrodes have emerged in the last decade, showing great potential on solving the problems that have prevented the widespread use of FES in clinical practice in the past: improving selectivity of stimulation, delaying muscle fatigue, and providing easier donning and doffing.^{13 14}

The Fesia Grasp system (Fesia Technology, Donostia–San Sebastián, Spain) is one of the FES devices used for hand dexterity rehabilitation and is the only one that is based on multifield electrodes. It works by delivering a train of biphasic pulses of different widths and amplitudes to different fields of the electrodes in an asynchronous manner. The system (figure 1) consists of a stimulating unit, a garment with an integrated multifield electrode (comprises 32 cathodes and eight anodes) and a tablet PC with a software application. The software application, called Fesia Pro, allows to configure the desired stimulation parameters and to monitor person evolution (figure 2).

Figure 1.

Fesia Grasp device. A: garment; B: stimulator; C: multifield electrode.

Figure 2.

Fesia Pro software application.

In order to guide future rehabilitation of these persons, it is important to provide specific examples of cases where clear rehabilitation goals have been implemented successfully, as evidenced with validated outcome measures, with the use of treatment options such as selective FES.

Case presentation

This person is a 69-year-old woman who suffered a cardioembolic ischaemic stroke on 23 September 2019 in the right middle cerebral (MCA) and anterior cerebral (ACA) arteries. It produced lesions on the right insula, right frontal lobe, right parietal lobe and temporal pole (observed in CT examinations). There was also a subarachnoid haemorrhage along with effacement of the adjacent sulci. These injuries resulted in a left hemiplegia with motor impairment in upper and lower extremities, hypoesthesia in the palmar and dorsal sides of the left hand and left quadrantanopia. No pain was reported. Table 1 shows the results of the clinical assessment of the left upper limb carried out before starting the intervention, which includes the following: FMA-UE; active range of motion (AROM) of the extension of the thumb (metacarpophalangeal joint), index (metacarpophalangeal joint) and wrist; Modified Ashworth Scale of the flexors of the fingers and wrist; and hand grip, measured with the Camry EH101 electronic hand dynamometer (Camry, South El Monte, California, USA).

Table 1.

Results of the measured parameters at baseline, after the 6-week physiotherapy intervention and 2 months after completion

Assessment	Baseline	Postintervention	Follow-up (2 months)
FMA-UE	85/126	104/126	106/126
Upper extremity	20/36	25/36	27/36
Wrist	3/10	7/10	7/10
Hand	6/14	13/14	13/14
Coordination	2/6	3/6	3/6
Sensation	8/12	10/12	10/12
Passive joint motion	24/24	24/24	24/24
Joint pain	24/24	24/24	24/24
AROM
Selective thumb extension	0°	25°	27°
Selective index extension	5°	15°	13°
Selective wrist extension	0°	18°	24°
MAS
Flexor muscles of the thumb	1/4	1/4	1/4
Flexor muscles of the fingers 2, 3, 4 and 5	0/4	0/4	0/4
Flexor muscles of the wrist	0/4	0/4	0/4
Hand grip	14.2 Kg	17.8 Kg	17.1 Kg

AROM, active range of motion; FMA-UE, Fugl-Meyer Assessment for the Upper Extremity; MAS, Modified Ashworth Scale.

She was diagnosed with atrial fibrillation and had a mechanical mitral valve implanted since 2015. She had no history of neurological or psychiatric disorders. She is retired, lives with her husband and was completely independent prior to the stroke (Barthel Index score 100).

Investigations

A head CT scan was performed on admission (initial CT scan), and there was no evidence of acute brain pathology. However, the initial CT angiogram showed narrowing and subsequent occlusion of the right MCA M2 branch, with relative paucity of arterial filling in the right frontal lobe distal to this. Afterwards, the head CT was repeated, which showed evolution of the right MCA and right ACA infarcts with involvement of the right insula, right frontal lobe, right parietal lobe and right temporal pole. There was also a local subarachnoid haemorrhage along with effacement of the adjacent sulci. See figures 3 and 4 for head CT examinations in the axial and frontal planes.

Figure 3.

Brain CT in the axial plane.

Figure 4.

Brain CT in the frontal plane.

Treatment

The person started her rehabilitation in Fesia Clinic rehabilitation centre (Donostia–San Sebastian, Spain) on 20 October 2020 (12.5 months after her stroke), doing two weekly sessions of 1 hour for 6 weeks. The treatment sessions were divided into the following three 20-minute parts.

Selective repetitive FES of antebrachial muscles

The first 20 min of the session was performed with the Fesia GRASP device (figure 5).

Figure 5.

Person wearing the Fesia Grasp device.

First, the therapy consisted of stimulating different forearm muscles cyclically, generating movements towards flexion and towards extension. The stimulated muscles and the movement generated by each of them are in table 2. The following stimulation parameters were used: frequency, 25 Hz; pulse width, 250 µs; intensity, 16–24 mA; and stimulation time, 2 s/cycle. The chosen posture to carry out the therapy was neutral pronosupination. No voluntary contraction was requested from the person, she was only encouraged to observe the movement that was being performed. Stimulation of the flexor and extensor muscles was alternated.

Table 2.

Movements and muscles stimulated with the FES device

Movement	Muscles
Wrist flexion	Flexor carpi ulnaris, palmaris longus, flexor carpi radialis, flexor digitorum superficialis
Finger flexion	Flexor digitorum superficialis
Thumb opposition	Flexor pollicis longus
Wrist extension	Extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum, extensor carpi ulnaris
Finger extension	Extensor digitorum, extensor digiti minimi
Thumb extension	Extensor pollicis brevis, extensor pollicis longus, abductor pollicis longus
Index extension	Extensor indicis

FES, functional electrical stimulation.

Then, after 10 min of repetitive muscle activations, they were combined with mirror therapy (MT), which has shown widely to be effective in improving certain functional parameters of the hand.¹⁵ In this way, the person observed in the mirror the movement of her healthy hand (although pretending that it was the paretic one) while, behind the mirror, the paretic hand was performing the same movement induced by FES (figure 6). The therapist, who could observe both hands, defined with oral instructions the moment at which the person should perform the movements with her right hand.

Figure 6.

Functional electrical stimulation and mirror therapy combination.

Selective voluntary contractions of antebrachial muscles

In this second phase, the same seven movements were repeated but in a voluntary way, without FES.

As in the previous phase, the contraction of the flexor and extensor muscles was alternated. In the first sessions, only the movements that could be performed selectively were executed, and as the person progressed, the rest were included. Although at the beginning the exercises were performed only in a neutral pronosupination position, in the last sessions, the movements were also performed with the forearm pronated and supinated, which was more difficult for her.

Then, after 10 min of voluntary contractions, the same selective movements were also performed combining them with MT. This was done during the 12 sessions that the treatment lasted.

Functional upper limb activities with FES of antebrachial muscles

The last part consisted in performing different functional actions with the upper extremity, involving hand and wrist movements. In this case, the main problem of the person was the thumb staying in a flexed position when opening the hand that made very difficult or impossible to grasp any object. An electrical current was applied to the thumb extensors in the exact moment that it was required, so that the hand opened completely, facilitating the grasping of different objects. It was done manually by the clinician with the software application. The stimulation parameters were the same as in the first part of the therapy/session.

Outcome and follow-up

The same clinical assessment carried out at baseline was repeated after the 6-week physiotherapy intervention and 2 months after completion. Results are shown in table 2.

From a functional perspective, the person is starting to use her paretic arm in daily living activities, such as switching lights on–off and holding her mobile phone. She takes care of most of her personal care although she still reports intermittent difficulties with some daily motor tasks.

Two months after the assessment, the person continues with her rehabilitation process (at a lower intensity, doing two weekly sessions of 30 min), through which she continues to improve at a functional level (table 1). There were no side effects related to FES.

Discussion

In this case report, we report the case of an adult person who suffered a cardioembolic ischaemic stroke. The focus on this case is the excellent results of the FES-based therapy programme (used in isolation and combined with MT) on the hand dexterity and functionality.

FES is an 1A evidence level therapy for the hand dexterity rehabilitation after stroke, and the clinical practice guidelines clearly recommend its use.¹⁶ However, it is a technique whose use has been limited in daily clinical practice, due to problems in the functionality and muscle selectivity that were commonly associated with the use of traditional electrodes.¹⁷ Multifield electrodes have shown to be a great option to optimise stimulation selectivity, when used in neurorehabilitation. The usability is the other main highlight of these types of electrodes decreasing configuration times and improving its clinical integration in the daily clinical practice.¹⁷ However, there are no clinical trials studying the differences of these electrodes in the clinical results obtained, compared with the use of traditional electrodes.

Our findings show that with a multimodal approach including multifield technology-based FES and MT, great rehabilitative effects are achieved in the upper limb in a person with stroke, several months after the event. In this case, the bigger change was observed in the motor function, where there was an increase of 20 points on the FMA-UE after 6 weeks of treatment. Furthermore, great improvements were also found in AROM and hand grip strength. These changes have allowed the person to involve her paretic arm in daily living activities, which was impossible before therapy, due to the lack of hand dexterity.

MT is one of the techniques used to improve motor function after stroke. Clinical trials indicate evidence for the effectiveness of MT for improving upper extremity motor impairment, motor function, pain and activities of daily living.¹⁸ In this case study, we have also showed the feasibility of combining MT with multifield FES devices. Different studies have demonstrated that the combination of FES with MT can be effective in improving certain functional parameters of the hand; however, the movement that was caused by the device was not selective, activating all the extensor muscles of the forearm at the same time.¹⁵ With the multifield electrode, we have been able to isolate eight different movements, combining each of them with MT. It is possible that, in part, the surprising results of this case are due to this.

We cannot speculate on whether the person’s functional recovery would have been enhanced if the treatment had been used at an acute phase. Further research in this field, as well as demonstrating its usefulness and efficacy in other injuries of the nervous system, is needed.

In conclusion, this case study provides an example of a successful hand dexterity rehabilitation process in a person with stroke carried out with a multimodal approach including high-technology FES and MT. This isolated finding is a proof of concept of implementing multifield FES in a multimodal rehabilitation treatment, and further research is warranted into the use of this technology in people with stroke and other neurological diseases.

Patient’s perspective.

When I began my rehabilitation at Fesia Clinic, my hand and arm mobility was very limited. My strength was correct, but it was uncontrolled, not useful. For example, turning the lights on–off was very difficult, unless it was pressed with the thumb. I was able to grasp medium-sized objects with my whole hand, although it was difficult to release them later (the objects remained ‘hooked’ in my hand). My thumb was all the time flexed, and I was unable to carry out the abduction of this finger, so that it was difficult to keep it in a neutral position that made complicated to grasp some objects. Furthermore, the mobility of the arm was very limited, performing movements in a ‘robotic’ way. The sensitivity of my hand was also less intensified than in the other side, being difficult to identify when an object was close enough to grasp it. Finally, regarding the neutral position of my hand, it tended to be rather closed and tense most of the time.

Once rehabilitation began, sensitivity, mobility and strength notably improved. In the case of the arm, nowadays, I can perform much more natural, fast and dynamic movements. The hand has also improved remarkably. The wrist changes position more agilely, and its range of motion is bigger. The most noticeable change has occurred in my fingers (especially in my thumb), which I can control much more than before the treatment. I am already beginning to carry out the abduction of the thumb, and to check that when closing the hand, this finger stays above the rest. This increased precision has allowed me to start performing the pinch movement, making it easier for me to grasp smaller objects. Strength has also improved, and now, I can control better the intensity, which is needed to grasp different types of objects. Sensitivity is also better, although it is still difficult for me to identify the area where my hand is being touched.

In summary, the most important change has been seen in the naturality of the arm, wrist and finger movements. The movements are more controlled and greater, mainly those that involve the thumb joints.

Learning points.

• Selective functional electrical stimulation (FES) could be used effectively as a rehabilitation technique of hand dexterity after stroke.

• Multifield FES devices are an optimal option to perform selective FES, because of their capacity to increase selectivity of stimulation, delay muscle fatigue and provide easier donning and doffing.

• The muscular selectivity offered by the multifield electrode allows to work isolated contractions in a repetitive way and, then, to integrate them into real functional activities by stimulating the movements, which are missing in each person.

• Multifield electrodes facilitate combining FES with mirror therapy, which has shown to be effective for upper limb rehabilitation after stroke.

Ethics statements

Patient consent for publication

Obtained.