The biomechanical effects of BTX-A on children with cerebral palsy
Research type
Research Study
Full title
The effects of botulinum toxin type A on the biomechanical and elastic properties of muscles and tendons in the upper extremity of children with spastic cerebral palsy.
IRAS ID
296396
Contact name
Angela E Kedgley
Contact email
Sponsor organisation
Imperial College London
Duration of Study in the UK
1 years, 7 months, 31 days
Research summary
Research Summary
Botulinum toxin type A (BTX-A) is a commonly used treatment for spastic cerebral palsy. This treatment has proved to show considerable improvements in excessive muscle contraction. However, we do not completely understand what BTX-A does to the tendons and muscles in the hand and forearm in terms of their physical properties. The purpose of this study is to understand the physical changes that occur in the muscles and tendons in the hand and forearm after BTX-A injections.
The participant’s will be aged between 4 and 18 years, will have been diagnosed with spastic cerebral palsy in their upper limb and will be due to start BTX-A treatment for their hand, wrist or forearm. The following measurements will be repeated at various times before and after the participant’s BTX-A treatment. The first session will be before the start of BTX-A treatment, the second session will be between 3 weeks and 6 months after treatment and the third session will be at least 6 months after treatment. Ultrasound will be used to look at the muscles and tendons in the participant’s wrist and forearm, particularly looking at the elastic and architectural properties. To look at how the participant’s muscles move, we use electromyography sensors on the participant’s wrist and forearm whilst they are performing a series of simple limb movements. The participant will be asked to perform a series of movements selected from the Shriners Hospital Upper Extremity Evaluation (SHUEE) test.Summary of Results
"The study measured the effects of Botulinum toxin type A (BTX-A) injections on the superficial forearm muscles and tendons of children with spastic cerebral palsy (CP). The results show that the average spontaneous functional analysis score (SFA) score increased by 8.61% and dynamic positional analysis (DPA) score increased by 7.86% after BTX-A injections. Additionally, three participants who had a score of 0 in the pre- BTX-A session for SFA score showed an increase in score post-BTX-A. However, at baseline the SFA and DPA scores varied across participants and five participants did not show any improvement in DPA post-BTX-A. As BTX-A does not directly address positional changes like surgical interventions, it is not surprising that no improvement was observed in some of the participants.
The mean modified Ashworth scale (MAS) score decreased from 2.13 to 1.71 after BTX-A injections, indicating an improvement in muscle architecture. The baseline for tendon and muscle CSA, along with the elastic modulus can be used together to identify changes in tendon properties and how well it will function particularly following surgical intervention. The effects of BTX-A are shown by a decrease in mean activation peak in EMG signals and a decrease in MAS score. The values of elastic modulii provide baselines of stiffness to expect in this population of children with spastic CP. This work provides a reference point for clinicians when making surgical decisions as the stiffness of the tendon can restrict the muscles’ ability to produce force."REC name
Wales REC 5
REC reference
22/WA/0305
Date of REC Opinion
12 Oct 2022
REC opinion
Further Information Favourable Opinion