Investigating muscle selection for botulinum toxin-A injections in adults with post-stroke upper limb spasticity.

Abstract

BACKGROUND: Limited empirical information exists regarding botulinum toxin-A injector decision-making practices for adult upper limb post-stroke spasticity. The design of most studies prevents such an assessment, as injection sites and dosage are mandated by researcher protocols. This contrasts to usual injector practices, where individualized decision-making is the standard of care. DESIGN: Secondary data analysis from an Australian randomized controlled trial of 90 adults with upper limb post-stroke spasticity where experienced clinicians followed their standard clinical injecting practice rather than a mandated injection regimen. METHODS: Clinicians were hypothesized to tailor their injection practices according to the subject's degree of spasticity and/or the type of functional gain desired. Hypothesis testing was conducted using non-parametric analysis. RESULTS: Muscle selection and botulinum toxin-A dosage were not significantly associated with spasticity severity or with patient-identified goals. Between-site differences in injection practices suggested that injector beliefs, rather than patient characteristics, were the dominant feature driving botulinum toxin-A injection strategy for post-stroke upper limb spasticity. CONCLUSION: This result looks into the "black box" of rehabilitation, revealing significant variation in injector beliefs. Findings suggest that further scientific work is required to maximize the efficacy of botulinum toxin-A injections in post-stroke upper limb spasticity management.