Development of an Agent-Based Model to Study the Mechanism of Effects of Botulinum Toxin on Muscle Tissue Adaptation

Local application of botulinum toxin type-A (BTXA) is commonly used for spasticity management in patients with cerebral palsy (CP), stroke, multiple sclerosis, as well as dystonia. However, recent studies on muscle mechanics have shown results contradictory to treatment aims (increased passive resistance, narrower joint range of motion). This is ascribed to muscle structure adaptations characterized by collagen increase, hereby this should be controlled. However, the mechanisms of these adaptations are not understood. Within this study, it is aimed to develop an agent-based model to understand these mechanisms. Based on our previous finite element analysis results, the effects of BTX-A were modeled as strain changes across the extracellular matrix of the muscle fascicle. The analyzes performed by agent-based models showed statistically significant increases in the collagen turnover, the collagen sum and the number of fibroblasts due to BTX-A.