Longitudinal Goal Attainment With Repeat Injections of AbobotulinumtoxinA in Adults With Lower Limb Spasticity: Results From a Prospective Observational Study

OBJECTIVE: To assess longitudinal goal attainment with repeat abobotulinumtoxinA (AboBoNT-A) injections for lower limb spasticity (LLS) over 16 months. DESIGN: Prospective, longitudinal, international, multicenter, observational study (NCT04050527). SETTING: Specialist neurorehabilitation centers. PARTICIPANTS: Ambulatory adults with unilateral LLS able to take ≥5 steps with/without assistance (effectiveness population, N=384). INTERVENTIONS: Participants received ≥1 AboBoNT-A treatment cycle administered in accordance with local prescribing guidelines to achieve individualized treatment goals. MAIN OUTCOME MEASURES: The primary endpoint was goal attainment as assessed using the cumulated Goal Attainment Scaling-Leg (GAS-leg) T score, across all treatment cycles for each patient. RESULTS: Overall, participants underwent a median of 5 lower limb injection cycles (median dose 600U, range 100-1475U) with a mean±SD injection interval of 18.3±6.1 weeks. Participants generally achieved their goals as expected over repeated cycles; the mean (95% CI) GAS-leg T score at cycle 1 baseline was 38.0 (37.7, 38.3) and the mean cumulated GAS-leg T score at 16 months was 48.2 (47.4, 48.9) (mean change from a baseline of 9.9 9.1, 10.7). Participants injected with a guidance technique at baseline were more likely to attain their cycle 1 primary treatment goals (odds ratio: 1.9 95% CI 1.1, 3.1, P=.02). Overall, 56 (13.5%) participants reported ≥1 adverse event, of which 6 participants (1.4%) had a treatment-related adverse event. CONCLUSIONS: Findings from this large, international study provide evidence for the benefit of repeated cycles of AboBoNT-A for LLS. Multivariate analyses indicated that goal attainment during the first cycle was better with those injected using injection guidance than those injected without guidance.