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.