Most Frequently Injected Muscles for Lower Limb Spasticity in Routine Practice: AboLiSh Study Baseline Data

Research Objectives: To describe abobotulinumtoxinA (aboBoNT-A) dosing parameters for the most commonly targeted muscles in the routine management of lower limb spasticity (LLS).

Design: AboLiSH (NCT04050527) is a prospective, longitudinal, observational study.

Setting: International, multicenter.

Participants: Adults aged ≥18 years with unilateral LLS, who are able to take ≥5 steps with or without assistance and are either botulinum toxin naïve or non-naïve.

Interventions: AboBoNT-A injections, in accordance with local prescribing guidelines (maximum dose 1500U). Prescription decisions were made prior to, and independently of study enrollment.

Main Outcome Measures: Documentation of injection parameters made at every visit where aboBoNT-A is injected (including technique, injection intervals and rehabilitation interventions) over 16 months.

Results: The baseline population includes 421 adults with LLS (mean±SD age 53.7±13.9 years; 65.1% male). The median total injected dose of aboBoNT-A was 600U, ranging from 100-1500U. A median of 4 muscles (range: 1-8) were injected, with most injections given under guidance (any 74.0%; EMG 41.0%, electrostimulation 32.3%, ultrasound 42.9%). The most commonly injected lower limb muscles (>20% patients) consisted of gastrocnemius medial head (injected in 82.7% of patients, median dose 150U), gastrocnemius lateral head (71.7%, 150U), soleus (66.5%, 200U), tibialis posterior (49.6%, 150U), flexor digitorum longus (39.0%, 100U), and flexor hallucis longus (22.1%, 100U). The use of injection guidance for these muscles ranged from 71.6% for the gastrocnemius medial head to 79.9% for the flexor digitorum longus.

Conclusions: In these baseline analyses, 6 muscles were identified as being most frequently injected in LLS. Injection practice was consistent with foot equinus and/or varus as the most common pattern of spasticity treated, in line with a key goal of improving mobility.

Author(s) Disclosures: RDZ: Received research support from and is a consultant for BrainQ and Ipsen. AE: Received research support from and is a consultant for Abbvie/Allergan and Ipsen. SA: Received honoraria from Ipsen, Abbvie/Allergan, Merz, and Danone; and research support from Ipsen. PM and SP: Employees of Ipsen. JJ: Received honoraria from Abbvie/Allergan, Merz, and Ipsen.