Long-term repeated botulinum toxin a treatment over 12 years gradually changes gait characteristics: single-case study

Objective: To demonstrate the long-term efficacy of repeated botulinum toxin A injections into the same muscles for ameliorating lower limb spasticity and gait function. Design: Single-case study Patient: A 36-year-old woman with right cerebral haemorrhage received her first botulinum toxin A injection 1,296 days after onset. The patient underwent 30 treatments over 12 years after the first injection to improve upper and lower limb spasticity and abnormal gait patterns. The mean duration between injections was 147 days. Methods: The Modified Ashworth Scale, passive range of motion, gait velocity, and degree of abnormal gait patterns during treadmill gait were evaluated pre-injection and at 2, 6, and 12 weeks after every injection. Results: The follow-up period showed no injection-related adverse events. Comfortable overground gait velocity gradually improved over 30 injections. The Modified Ashworth Scale and passive range of motion improved after each injection. Pre-injection values of the degree of pes varus, circumduction, hip hiking, and knee extensor thrust improved gradually. However, the degree of contralateral vaulting, excessive lateral shift of the trunk, and insufficient knee flexion did not improve after 30 injections. Conclusion: Repeated botulinum toxin A injections effectively improve abnormal gait patterns, even when a single injection cannot change these values.