Safety and efficacy of abobotulinumtoxinA for hemiparesis in adults with upper limb spasticity after stroke or traumatic brain injury: a double-blind randomised controlled trial
Abstract
Background Resistance from antagonistic muscle groups might be a crucial factor reducing function in chronic hemiparesis. The resistance due to spastic co-contraction might be reduced by botulinum toxin injections.
We assessed the effects of abobotulinumtoxinA injection in the upper limb muscles on muscle tone, spasticity, active movement, and function. Methods In this randomised, placebo-controlled, double-blind study, we enrolled adults (aged 18-80 years) at least 6 months after stroke or brain trauma from 34 neurology or rehabilitation clinics in Europe and the USA.
Eligible participants were randomly allocated in a 1: 1: 1 ratio with a computer-generated list to receive a single injection session of abobotulinumtoxinA 500 U or 1000 U or placebo into the most hypertonic muscle group among the elbow, wrist, or finger flexors (primary target muscle group [PTMG]), and into at least two additional muscle groups from the elbow, wrist, or finger flexors or shoulder extensors. Patients and investigators were masked to treatment allocation.
The primary endpoint was the change in muscle tone (Modified Ashworth Scale [MAS]) in the PTMG from baseline to 4 weeks. Secondary endpoints were Physician Global Assessment (PGA) at week 4 and change from baseline to 4 weeks in the perceived function (Disability Assessment Scale [DAS]) in the principal target of treatment, selected by the patient together with physician from four functional domains (dressing, hygiene, limb position, and pain).
Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01313299.