Intramuscular Neural Distribution of Adductor Pollicis Muscle Spasticity in Cadaver Model Regarding Botulinum Neurotoxin Treatment

Abstract

Purpose The adductor pollicis muscle is frequently targeted for botulinum neurotoxin injective treatment for spasticity. However, there are no injective guidelines for delivering injection to the muscle. Materials and Methods A method known as the modified Sihler’s method was used to stain the adductor pollicis muscle in 16 specimens to reveal intramuscular neural distribution of the muscle. Results The most intramuscular neural distribution was located on 1/5 to 3/5 of the muscle regarding midline of 3rd metacarpal bone (0) to the base of the 1st proximal phalanx (5/5). The nerve entry point was mostly located on 0 to 1/5 of the muscle. Conclusion The result suggests that botulinum neurotoxin should be delivered at the middle of second metacarpal bone via deep injection.