Effect of intensive functional electrical stimulation therapy on upper-limb motor recovery after stroke: case study of a patient with chronic stroke

Abstract

Purpose: Motivated by a prior successful randomized controlled trial showing that functional electrical stimulation (FES) therapy can restore voluntary arm and hand function in people with severe stroke, this study was designed to examine neuromuscular changes in the upper limb following intensive FES therapy, consisting of task-specific upper-limb movements with a combination of preprogrammed FES and manual assisted motion.

Methods: The patient was a 22-year-old woman who had suffered a haemorrhagic stroke 2 years earlier. FES therapy was administered for 1 hour twice daily for 12 weeks, for a total of 108 treatment sessions.

Results: While maximal voluntary contraction level of the upper-limb muscles did not show significant improvement, the ability to initiate and stop the muscle contraction voluntarily was regained in several upper-limb muscles (approx. 5%-15% of the maximum voluntary contraction of the same muscle in the less-affected arm). A reduction in arm spasticity was also observed, as indicated by the reduction of H-reflex in the wrist flexor muscle (82.1% to 45.0% in Hmax/Mmax) and decreased Modified Ashworth Scale scores (from 3 to 2 for the hand and 4 to 3 for the arm). Coordination between shoulder and elbow joints during the circle-drawing test improved considerably over the course of FES therapy: the patient was unable to draw a circle at all at baseline but was able to do so proficiently at discharge.

Conclusion: Improvements in upper-limb function observed in people with severe stroke following intensive FES therapy can be attributed to (a) regained ability to voluntarily contract muscles of the affected arm, (b) reduced spasticity and improved muscle tone in the same muscles, and (c) increased range of motion of all joints.

Keywords: functional electrical stimulation; muscle spasticity; neuronal plasticity; rehabilitation; stroke; upper limb.

Figures

Figure 1

(a) schematic picture of functional motion tasks (left) and schematic examples of shoulder- and elbow-joint angle changes and stimulus pattern for each muscle (right); thick and thin lines indicate joint motion and stimulus pattern (timing of ON/OFF). (b) Location of electrodes.

Figure 2

(a) recruitment curves of the H-reflex and M wave; (b) changes in M wave and H-reflex response to stimulus intensity; (c) change in H-reflex and M response over the course of training.

Figure 3

(a) Change over time in maximal voluntary contraction level of first distal interosseous muscles (FDI), flexor capi radialis (FCR), extensor digitorum (EDL), biceps brachialis (BB), triceps brachialis (TB), anterior (aDel) and posterior deltoid (pDel) muscles; black (print) / blue (online) bar=data from right (less affected side) arm. (b) EMG pattern in FCR muscle at initiation of voluntary muscle contraction.

Figure 4

Trajectory of the shoulder, elbow, wrist, and index finger as the patient performed the circle-drawing test: (a) absolute positions of individual joints; (b) positions normalized with respect to the shoulder joint.