Quantification and Monitoring of the Effect of Botulinum Toxin A on Paretic Calf Muscles of Children With Cerebral Palsy With MRI: A Preliminary Study

Background: Muscles from patients with cerebral palsy (CP) are often spastic and form contractures that limit the range of motion. Injections botulinum toxin A (BTX) into calf muscles an important treatment for functional equinus; however, improvement in gait function is not always achieved. BTX also used to test muscle weakening risk evaluation lengthening surgery. Our aim was assess effect over time on properties pediatric CP MRI. Material Methods: Six toe-walking (mean age 11.6 years) indication surgery were prospectively enrolled received injections gastrocnemius soleus muscles. MRI scans at 3T lower legs clinical examinations performed pre-BTX, 6 weeks (6w), 12 (12w) post-BTX. fat-suppressed 2D multi-spin-echo sequence acquire T 2 maps segmentation. Fat fraction calculated 3D multi-echo Dixon images. Diffusion tensor imaging (DTI) a echo-planar (EPI) yielded mean apparent diffusion coefficient (ADC) fractional anisotropy (FA). Hyperintense regions interest (ROIs) -weighted (T w) images 6w segmented treated Mean values , fat fraction, ADC, FA hyperintense ROIs reference non-treated Results: Hyperintensity w increased (group ± standard deviation: 35 1 ms 45 6w, 44 12w) observed all injection sites. The increase spatially limited parts injected (0.30 0.03 0.34 0.02 0.36 while ADC did change ROIs, indicating BTX-induced extracellular space simultaneous decrease fiber diameter. showed trend 12w. remained unchanged. Conclusion: spatial distribution effects patients. It could be promising non-invasive tool future studies protocols.