Effects of 3 Cycles of Progressively Higher Doses of botulinum Toxin on Sagittal Kinematic Gait Parameters in People with Multifocal Spasticity After Stroke: A Prospective Cohort Study

Abstract

Introduction

Gait kinematic analysis is essential for evaluating walking quality and efficacy of interventions. Spastic gait varies among individuals, even when they present similar postural gait patterns. While previous studies have reported functional gait improvements following repeated botulinum toxin-A (BT-A) injections, effects on gait kinematics remain unclear.

Methods

This prospective cohort study assessed sagittal gait kinematics in adults with chronic stroke-related multifocal spasticity, who received three cycles of progressively higher doses of Inco BT-A (400, 600, and 800 U). Quantified gait analysis (QGA) was performed before and after the first injection cycle and after the last. To account for inter-individual variability, sagittal kinematic variables that best reflected individual postural gait patterns were identified.

Results

Twenty-five participants were included. Sagittal kinematic improvements were not observed after the first injection cycle but became apparent after the third. Significant improvements were observed in two postural gait patterns: pes equinus during stance, with a mean increase in ankle dorsiflexion of 3° (SD = 6°, p = 0.008), and stiff knee gait, with a mean increase in knee flexion during swing of 7° (SD = 7°, p < 0.001).

Conclusion

This study showed effects of progressively higher doses of BT-A on sagittal knee and ankle kinematics in individuals with multifocal spasticity after chronic stroke, suggesting that three cycles of progressively higher doses are necessary to achieve measurable kinematic improvements. These results align with functional gains from our larger study, underscoring the importance of individualized gait assessments in clinical decision-making on post-stroke spastic gait.