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Quantitative evaluation for spasticity of calf muscle after botulinum toxin injection in patients with cerebral
Yu-Ching Lin1,2,3, I-Ling Lin4, Te-Feng Arthur Chou1,5
1Department of Physical Medicine and Rehabilitation, College of Medicine, National Cheng Kung University, No.1, University Road, Tainan City, 701, Taiwan.
Insights
A new device quantitatively measures spasticity in children with cerebral palsy (CP) after botulinum toxin type A (BoNT-A) injections. The device shows improvements in both neural and non-neural components of calf muscle spasticity.
Area of Science:
- Biomedical Engineering
- Pediatric Neurology
- Rehabilitation Medicine
Background:
- Cerebral palsy (CP) is a leading cause of pediatric motor disability, often involving calf muscle spasticity and contracture.
- Impaired ankle plantar flexor function in children with CP significantly impacts gait and daily activities.
- Botulinum toxin type A (BoNT-A) injections are common for reducing muscle tone, but objective assessment of spasticity components post-injection is lacking.
Purpose of the Study:
- To develop and validate a device for quantitative measurement of calf muscle spasticity using a modified Tardieu approach (QMTA).
- To assess changes in neural and non-neural components of spasticity after BoNT-A injection in children with CP.
Main Methods:
- Developed a portable device (QMTA) integrating biomedical engineering techniques with the modified Tardieu scale (MTS).
- QMTA measures joint angular displacement and resistance during muscle stretch, calculating static (R2) and dynamic (R1) angles.
- Four children with CP were assessed pre- and 4 weeks post-BoNT-A injection, measuring gastrocnemius muscle spasticity.
Main Results:
- A simulated ankle model confirmed the device's accuracy in measuring joint displacement and catch angle.
- Participants with CP demonstrated significant improvements in R2 and R2-R1 values 4 weeks after BoNT-A injection.
- Results indicate that both neural and non-neural components of gastrocnemius spasticity improved post-BoNT-A treatment.
Conclusions:
- The developed QMTA device provides an objective method for evaluating changes in gastrocnemius muscle spasticity in children with CP following BoNT-A treatment.
- This quantitative approach enhances understanding of BoNT-A's effects on the complex components of spasticity.
Background:
Cerebral palsy (CP) is the most common pediatric disease to cause motor disability. Two common symptoms in CP are spasticity and contracture. If this occurred in the ankle plantar flexors of children with CP, it will impair their gait and active daily living profoundly. Most children with CP receive botulinum toxin type A (BoNT-A) injection to reduce muscle tone, but a knowledge gap exists in the understanding of changes of neural and non-neural components of spasticity after injection. The purpose of this study was to determine if our device for quantitative modified Tardieu approach (QMTA) is a valid method to assess spasticity of calf muscles after botulinum toxin injection.
Methods:
In this study, we intended to develop a device for quantitative measurement of spasticity in calf muscles based on the modified Tardieu scale (MTS) and techniques of biomedical engineering. Our QMTA measures the angular displacement and resistance of stretched joint with a device that is light, portable and can be operated similar to conventional approaches for MTS. The static (R2), dynamic (R1) and R2-R1 angles derived from the reactive signals collected by the miniature sensors are used to represent the non-neural and neural components of stretched spastic muscles. Four children with CP were recruited to assess the change in spasticity in their gastrocnemius muscles before and 4 weeks after BoNT-A injection.
Results:
A simulated ankle model validated the performance of our device in measuring joint displacement and estimating the angle of catch. Data from our participants with CP showed that R2 and R2-R1 improved significantly after BoNT-A administration. It indicates both neural and non-neural components of the spastic gastrocnemius muscles improved at four weeks after BoNT-A injection in children with CP.
Conclusion:
Our device for QMTA can objectively measure the changes in spasticity of the gastrocnemius muscle in children with cerebral palsy after BoNT-A injection.
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