Objective: The aim of this study was to explore in vivo the effects of botulinum toxin-A treatment on the muscle architecture of patients with stroke, using musculoskeletal ultrasonography.
Methods: This prospective clinical trial included 26 adult stroke sufferers with a mean age of 55 years (standard deviation 14). Pennation angles between the fascicle path and the deep aponeurosis of the muscle, fascicle length, muscle thickness and muscle compressibility were scanned at the bulkiest part of the medial gastrocnemius on both limbs. Sonographic evaluations were performed initially before botulinum toxin-A injection and repeated on day 10 and after 2 months.
Results: On the hemiplegic sides, anterior pennation angle and muscle thickness decreased (p = 0.014, p = 0.010, respectively), fascicle length increased (p = 0.025) and muscle compressibility did not change after 2 months of treatment compared with the baseline values.
Conclusion: The results confirm that muscle structure changes due to botulinum toxin-A. Long-term effects of botulinum toxin-A, timing for disappearance of the toxin effects, or evaluations for repeat injections, remain to be studied. The use of musculoskeletal ultrasonography appears to be promising in this regard. :