title: Architectural changes of the gastrocnemius muscle after botulinum toxin type A injection in children with cerebral palsy.
abstract: OBJECTIVE
  This study used ultrasonography (US) to investigate the architectural changes in gastrocnemius muscles (GCM) after botulinum toxin injection (BoNT-A) in children with cerebral palsy (CP).
  
  
  METHODS
  Thirteen children with CP who received a BoNT-A injection into their GCM to treat equinus were recruited (9 males and 4 females). Architectural changes in both the medial and lateral heads of the GCM from a total of 20 legs were assessed using B-mode, real-time US. Muscle thickness (MT), fascicle length (FL), and fascicle angle (FA) were measured over the middle of the muscle belly in both a resting and neutral ankle position. Measures at 1 and 3 months after the injection were compared with baseline data taken before the injection.
  
  
  RESULTS
  The mean age of the subjects was 5.8 (±1.6) years. Spasticity was significantly reduced when measured by both the modified Tardieu scale and the modified Ashworth scale at 1 and 3 months after injection (p<0.05). The MT and FA of both the medial and lateral heads of the GCM were significantly reduced for both neutral and resting ankle positions at 1 and 3 months after the injection. The FL of both the medial and lateral heads of the GCM were significantly increased in a resting position (p<0.05), but not in a neutral position.
  
  
  CONCLUSIONS
  Our results demonstrated muscle architectural changes induced by BoNT-A injection. The functional significances of these changes were discussed.
authors.affiliation: Department of Rehabilitation Medicine, Severance Hospital, Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Park
authors.affiliation: Department of Rehabilitation Medicine, Severance Hospital, Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eungeol
authors.initials: E
authors.lastname: Sim
authors.affiliation: Department of Rehabilitation Medicine, Severance Hospital, Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Rha
authors.affiliation: Department of Rehabilitation Medicine, Severance Hospital, Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea. werch@yuhs.ac.
authors.forename: Soojin
authors.initials: S
authors.lastname: Jung
mesh_terms: D065087:Acetylcholine Release Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D001905:Botulinum Toxins / Q000009:adverse effects* / Q000627:therapeutic use; D002547:Cerebral Palsy / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000187:drug effects*; D014463:Ultrasonography
chemical_list: D065087:Acetylcholine Release Inhibitors; D001905:Botulinum Toxins
keywords: Botulinum toxin type A; cerebral palsy; ultrasonic imaging