Combined Effects and Timing of Robotic Training and Botulinum Toxin on Upper Limb Spasticity and Motor Function among individuals with post-stroke upper limb spasticity

Abstract

Objective:This study aimed to evaluate the combined effects of robotic training (RT) and botulinum toxin (BTX) injections on motor function and spasticity in individuals with post-stroke upper limb spasticity (ULS). We also investigated the optimal timing of RT and BTX administration. Methods:Forty-two participants with chronic stroke-induced ULS were initially enrolled and randomized into four groups: Group A (RT+BTX at 4 weeks [W4]), Group B (RT+BTX at baseline [W0]), Group C (BTX at W0, RT at W4), and Group D (RT at W0, BTX at W4). Clinical assessments and robotic kinematic evaluations were conducted at W0, W4, and 8 weeks (W8). The primary outcome was the Fugl-Meyer Assessment (FMA) scores, and secondary outcomes included the modified Ashworth scale (MAS) of elbow and kinematic parameters such as spectral arc length mean speed, hand path ratio, and movement deviation in various movements. Results:Of the 42 participants, 40 completed the study. From W0 to W4, Group B showed the best results in terms of spasticity (MAS-elbow flexor and extensor) and kinematic variables, indicating that the combined use of BTX and RT is superior to sole interventions regarding motor function and spasticity. From W0 to W8, Group C demonstrated the most significant improvements in FMA scores and kinematic variables, indicating that the combined use of BTX and RT, especially when RT was initiated one month after BTX injection, resulted in superior functional outcomes compared to other timings of interventions. Conclusions: The combination of RT and BTX is more effective in enhancing motor function and reducing spasticity in individuals with ULS than either intervention alone or no intervention. Moreover, the timing of RT relative to BTX injection plays a crucial role in maximizing therapeutic benefits in stroke patients with ULS, considering the mode of action of each intervention. Trial registration: clinicaltrials.gov NCT02228863. Registered 23 Auguste 2014; retrospectively registered.