Bilateral versus Unilateral Training With Rhythmic Auditory Cueing in Stroke Rehabilitation: Effects on Upper Limb Function and Interhemispheric Inhibition.

Abstract

Background: Stroke is a leading cause of long-term disability in adults, with upper limb hemiparesis being a common impairment. Traditional training is mostly aimed at paralyzed limbs, but the effect of bilateral training is still unclear.

Objective: This study explores the influence and mechanism of unilateral and bilateral rhythmic task training on the rehabilitation of stroke patients.

Study design: This was a double-blind randomized controlled trial.

Methods: Thirty-six patients were randomly assigned to the bilateral group or to the unilateral group. The bilateral group engaged in repetitive training involving both arms and distal hand movements, while the unilateral group focused on the affected arm. Evaluations were performed before treatment and immediately after treatment. The outcome measures included Fugl-Meyer Upper Extremity (FMA-UE), the average electromyographic values of a total of 16 muscle groups on both the unaffected and affected sides (with 8 muscle groups on each side) during maximum voluntary isometric contraction, as well as the active range of motion (ROM). Changes in interhemispheric inhibition (IHI) were assessed using transcranial magnetic stimulation.

Results: Post-treatment assessments indicated that the FMA-UE scores significantly increased in both groups, with the bilateral group exhibiting more pronounced improvements (p = 0.031; ηp² = 0.130). Specifically, compared to their pre-treatment states, the bilateral group showed statistically significant differences in the maximum EMG amplitudes of the anterior deltoid (p = 0.006; ηp² = 0.204) and wrist flexor muscles (p < 0.001; ηp² = 0.308) on the affected side, with greater gains than the unilateral group. Additionally, the maximum EMG amplitudes of the biceps brachii (p = 0.035; ηp² = 0.124) and wrist extensors (p = 0.018; ηp² = 0.153) on the unaffected side were significantly enhanced in the bilateral group. In terms of active ROM, the bilateral group demonstrated significant improvements in shoulder flexion (p = 0.024; ηp² = 0.142) and wrist flexion (p = 0.020; ηp² = 0.149), which surpassed those observed in the unilateral group. Furthermore, a significant reduction in IHI (p = 0.023; ηp² = 0.196) was observed, which was positively correlated with FMA-UE scores following bilateral training (r = 0.85, p < 0.001).

Conclusion: Bilateral training is more effective than unilateral training in enhancing upper limb function and may contribute to balancing IHI in stroke recovery patients.