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. FINDINGS: 243 patients were randomly allocated to placebo (n=81), abobotulinumtoxinA 500 U (n=81), or abobotulinumtoxinA 1000 U (n=81). Mean change in MAS score from baseline at week 4 in the PTMG was -0·3 (SD 0·6) in the placebo group (n=79), -1·2 (1·0) in the abobotulinumtoxinA 500 U group (n=80; difference -0·9, 95% CI -1·2 to -0·6; p<0·0001 vs placebo), and -1·4 (1·1) in the abobotulinumtoxinA 1000 U group (n=79; -1·1, -1·4 to -0·8; p<0·0001 vs placebo). Mean PGA score at week 4 was 0·6 (SD 1·0) in the placebo group (n=78), 1·4 (1·1) in the abobotulinumtoxinA 500 U group (n=80; p=0·0003 vs placebo), and 1·8 (1·1) in the abobotulinumtoxinA 1000 U group (n=78; p<0·0001 vs placebo). Mean change from baseline at week 4 in DAS score for the principal target of treatment was -0·5 (0·7) in the placebo group (n=79), -0·7 (0·8) in the abobotulinumtoxinA 500 U group (n=80; p=0·2560 vs placebo), and -0·7 (0·7) in the abobotulinumtoxinA 1000 U group (n=78; p=0·0772 vs placebo). Three serious adverse events occurred in each group and none were treatment related; two resulted in death (from pulmonary oedema in the placebo group and a pre-existing unspecified cardiovascular disorder in the abobotulinumtoxinA 500 U group). Adverse events that were thought to be treatment related occurred in two (2%), six (7%), and seven (9%) patients in the placebo, abobotulinumtoxinA 500 U, and abobotulinumtoxinA 1000 U groups, respectively. The most common treatment-related adverse event was mild muscle weakness. All adverse events were mild or moderate. INTERPRETATION: AbobotulinumtoxinA at doses of 500 U or 1000 U injected into upper limb muscles provided tone reduction and clinical benefit in hemiparesis. Future research into the treatment of spastic paresis with botulinum toxin should use active movement and function as primary outcome measures. FUNDING: Ipsen.

2nd Department of Neurology Comenius University and University Hospital Bratislava Slovakia

Assesoria Croissance Santiago Chile

Department of Neurology 1st Faculty of Medicine Charles University and General Faculty Hospital Prague Czech Republic

Department of Neurology Jagiellonian University Medical College Krakow Poland

EA 7377 BIOTN Université Paris Est Hospital Albert Chenevier Henri Mondor Service de Rééducation Neurolocomotrice Créteil France

Ipsen Innovation Les Ulis France

Neurology Department Federal State Hospital Treatments and Rehabilitation Center of Ministry of Health and Social Development of Russian Federation Moscow Russia

New England Institute for Neurology and Headache Stamford CT USA

Northwestern University and Rehabilitation Institute of Chicago Chicago IL USA

Service de Médecine Physique et de Réadaptation Centre Hospitalier Universitaire Dinant Godinne Université catholique de Louvain Namur Yvoir Belgium

State Budgetary Educational Institution of Higher Professional Education St Petersburg State Medical University 1 P Pavlov St Petersburg Russia

University of North Carolina Chapel Hill NC USA

University of Texas Southwestern Medical Center Dallas TX USA

University of Utah School of Medicine Division of Physical Medicine and Rehabilitation Salt Lake City UT USA

Wake Forest University School of Medicine Department of Neurology Winston Salem NC USA

Lancet Neurol. 2015 Oct;14(10):969-71. doi: 10.1016/S1474-4422(15)00222-7. PubMed

References provided by Crossref.org

When can maximal efficacy occur with repeat botulinum toxin injection in upper limb spastic paresis?

Guided Self-rehabilitation Contracts Combined With AbobotulinumtoxinA in Adults With Spastic Paresis

Sustained efficacy of incobotulinumtoxina repeated injections for upper-limb post-stroke spasticity: A post hoc analysis

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ClinicalTrials.gov
NCT01313299