title: Quantitative assessment of muscle stiffness with acoustic radiation force impulse elastography after botulinum toxin A injection in children with cerebral palsy.
abstract: OBJECTIVE
  Our objective in this study was to assess the changes in medial gastrocnemius muscle (GCM) stiffness after botulinum toxin A (BTA) injection in children with cerebral palsy (CP) by using acoustic radiation force impulse (ARFI) elastography and to research the usability of this technique in clinical practice.
  
  
  METHODS
  Twenty-four spastic lower extremities of 12 children with CP were assessed. BTA injection treatment was applied to the medial GCM. Muscle stiffness was measured with the ARFI technique before the procedure and a month after the procedure. The patients were assessed with the modified Ashworth scale (MAS) in the physiotherapy department at about the same time. Shear wave velocity (SWV) values and MAS scores before and after the treatment were compared.
  
  
  RESULTS
  Mean SWV values were measured as 3.20 ± 0.14 m/s before BTA and as 2.45 ± 0.21 m/s after BTA, and the difference between them was found to be statistically significant (p < 0.001). Mean MAS score (2.33 ± 0.70) after BTA decreased significantly when compared to the score before BTA (2.96 ± 0.62) (p = 0.001). SWV values positively correlated with MAS scores (ρ = 0.578, p = 0.003). The interobserver agreement expressed as interclass correlation coefficient (ICC) was 0.65 (95% CI 0.33-0.84, p < 0.001).
  
  
  CONCLUSIONS
  ARFI elastography for identifying structural changes that occur in the spastic muscle after BTA injection in children with CP can yield more valuable information with combined use of MAS.
authors.affiliation: Ondokuz Mayis University Faculty of Medicine, Department of Radiology, Samsun, Turkey.
authors.forename: Meltem
authors.initials: M
authors.lastname: Ceyhan Bilgici
authors.affiliation: Zonguldak State Hospital, Radiology Clinic, Zonguldak, Turkey. tmybkc@gmail.com.
authors.forename: Tumay
authors.initials: T
authors.lastname: Bekci
authors.affiliation: Ondokuz Mayis University Faculty of Medicine, Department of Physical Therapy and Rehabilitation, Samsun, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Ulus
authors.affiliation: Ondokuz Mayis University Faculty of Medicine, Department of Physical Therapy and Rehabilitation, Samsun, Turkey.
authors.forename: Ayhan
authors.initials: A
authors.lastname: Bilgici
authors.affiliation: Ondokuz Mayis University Faculty of Medicine, Department of Medical Biostatistics, Samsun, Turkey.
authors.forename: Leman
authors.initials: L
authors.lastname: Tomak
authors.affiliation: Ondokuz Mayis University Faculty of Medicine, Department of Radiology, Samsun, Turkey.
authors.forename: Mustafa Bekir
authors.initials: MB
authors.lastname: Selcuk
mesh_terms: D000293:Adolescent; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D002547:Cerebral Palsy / Q000150:complications*; D002648:Child; D054459:Elasticity Imaging Techniques; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D009128:Muscle Spasticity / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000209:etiology; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000187:drug effects; D009465:Neuromuscular Agents / Q000008:administration & dosage*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: ARFI elastography; Botulinum toxin A; Cerebral palsy; Gastrocnemius muscle; Muscle spasticity