Muscle selection and dosing in patients undergoing treatment with abobotulinumtoxinA for lower limb spasticity in real-world practice.

Objective: Describe abobotulinumtoxinA (aboBoNT-A) dosing parameters in the real-world management of lower limb spasticity (LLS).

Methods: Prospective, observational study (NCT0​4050527) following ambulatory adults with unilateral LLS treated with aboBoNT-A.

Results: The effectiveness population included 384 adults with LLS. Across the study, total lower limb doses were higher in patients who received only lower limb injections (n = 131, median 771U) than those who also received ≥ 1 upper limb injection (n = 253, 567U). Total doses increased over subsequent cycles in both subgroups. Six muscles (gastrocnemius medial and lateral heads, soleus muscle, tibialis posterior, flexor digitorum longus, and flexor hallucis longus) were identified as the main targets for the treatment of LLS; other lower limb muscles were injected in fewer than 15% of patients. The most frequent therapy interventions (mean ± SD of 1.8 ± 1.3h/week with a qualified therapist and 5.3 ± 5.9h/week self-rehabilitation in Cycle 1) were task-specific practice, passive stretch, strength training, and positioning.

Conclusions: This study demonstrates how a diversity of muscle patterns are currently treated in routine practice where the primary goal was related to the lower limb and highlights important issues for further debate, such as potential underdosing and the need to balance upper and lower limb priorities when devising a treatment plan.