Quantitative Effects of Botulinum Toxin Treatment on the Modified Ashworth Scale and the Tardieu Scale: Results from a Randomized Controlled Study of AbobotulinumtoxinA in Children with Dynamic Equinus Foot Deformity due to Cerebral Palsy (I15.003)

Objective: Assess the efficacy of abobotulinumtoxinA (ABO) versus placebo in improving measures of muscle tone and spasticity in children with equinus foot due to cerebral palsy (CP). Background: Although the Modified Ashworth Scale (MAS) is considered standard practice when assessing spasticity interventions, it is argued that the Tardieu scale (TS) is a more appropriate measure for assessing muscle overactivity because it considers the velocity of the limb movement according to the definition of spasticity. This is the first pediatric study to assess the effects of botulinum toxin on both muscle tone (using MAS) and spasticity (using TS). Methods: Phase 3 study in children (2-17y) with dynamic equinus foot. Patients (N=241) were randomized to placebo, ABO 10U/kg/leg or 15U/kg/leg injected into the gastrocnemius-soleus complex. Efficacy was assessed at weeks 4 and 12. Results: Treatment with ABO (both doses) significantly reduced muscle tone (MAS) at Week-4 and Week-12 (all pu003c0.05 vs. placebo) and there were significantly more responders (≥1 MAS grade improvement) in the ABO 15U/kg/leg group (Week-4 and Week-12, pu003c0.01 vs. placebo). Spasticity was also significantly improved with ABO; the angle of catch (XV3; passive fast speed) was increased versus placebo at Week-4 and Week-12 in the 15U/kg/leg group (10.9° and 9.6° both pu003c0.01) and at Week-12 in the 10U/kg/leg group (7.2° pu003c0.05); the spasticity grade (Y) was reduced for both doses at Week-4 and Week-12 (all p≤0.0003 versus placebo). Significant correlations (Pearson correlations all pu003c0.05) at both timepoints were consistently observed between the change from baseline in MAS and the TS spasticity grade and TS spasticity angle (X). Conclusions: These results suggest that TS assessments (angle of catch: passive fast speed XV3 and severity grade Y) are sensitive to treatment-induced changes after ABO injection in CP patients, allowing quantification of the improvements in the pediatric setting.Study Supported by Ipsen Disclosure: Dr. Tilton has received personal compensation for activities with Ipsen as a consultant. Dr. Tilton has received license fees/payments from LSUHSC. Dr. Tilton has received research support from Ipsen. Dr. Dabrowski has received research support from Ipsen. Dr. Matthews has received research support from Ipsen. Dr. Gormley has received research support from Ipsen. Dr. Jorge Carranza has received research support from Ipsen. Dr. Volteau has received personal compensation for activities with Ipsen as an employee. Dr. Picaut holds stock and/or stock options in Ipsen.