Spasticity is a type of hypertonia (increased muscle tone) that is velocity-dependent, meaning the faster a muscle is stretched, the more it resists movement. It is a common feature in spastic cerebral palsy, which is the most prevalent type of CP.
Tone refers to the resistance of muscles to passive movement. Increased tone (hypertonia) can occur in spasticity and other conditions like rigidity or dystonia.
Regular spasticity and tone assessment in children with CP is essential for personalized treatment, preventing complications, and maximizing functional potential. It ensures that interventions are timely, effective, and tailored to each child’s needs.
Importance of Spasticity and Tone Assessment in Children with Cerebral Palsy
Assessing spasticity and muscle tone in children with cerebral palsy (CP) is crucial for several reasons, as it directly impacts treatment planning, functional ability, and overall quality of life. Here’s why it matters:
1. Guides Treatment and Management
- Helps determine the most appropriate therapy (e.g., physiotherapy, occupational therapy, or surgical interventions).
- Identifies children who may benefit from medications (e.g., baclofen, diazepam), botulinum toxin injections, or intrathecal baclofen pumps.
- Assists in deciding whether orthotic devices, splints, or assistive mobility aids are needed.
2. Differentiates Spasticity from Other Forms of Hypertonia
- Not all cases of increased muscle tone are due to spasticity—some children may have rigidity or dystonia.
- Proper differentiation ensures targeted treatments (e.g., dystonia responds better to deep brain stimulation rather than botulinum toxin).
3. Prevents Complications
- Uncontrolled spasticity can lead to contractures (permanent muscle shortening), joint deformities, and hip dislocations.
- Early assessment allows for preventive measures like stretching programs, serial casting, or orthopedic surgeries.
4. Monitors Disease Progression and Treatment Effectiveness
- Allows healthcare providers to track changes in tone and spasticity over time.
- Helps in assessing the effectiveness of interventions like physical therapy, botulinum toxin injections, or selective dorsal rhizotomy (SDR).
5. Improves Functional Abilities and Independence
- Identifies whether reducing spasticity will improve walking, sitting, reaching, and other daily activities.
- Helps in setting realistic rehabilitation goals based on the child’s Gross Motor Function Classification System (GMFCS) level.
6. Enhances Quality of Life
- Reducing excessive tone and spasticity can decrease pain, improve sleep, and enhance overall comfort.
- Improves participation in activities, school, and social interactions.
7. Supports Decision-Making for Surgery
- Helps determine if a child is a candidate for procedures like:
- Selective Dorsal Rhizotomy (SDR) – for children with severe spasticity affecting mobility.
- Orthopedic surgeries – for correcting contractures or joint deformities.
Measuring tools to assess Spasticity & Tone
Modified Ashworth Scale (MAS) – Measures muscle spasticity.
Modified Tardieu Scale (MTS) – Evaluates muscle tone and spasticity.
Selective Control Assessment of the Lower Extremity (SCALE) – Assesses selective motor control.
Comparison table for the Modified Ashworth Scale (MAS), Modified Tardieu Scale (MTS), and Selective Control Assessment of the Lower Extremity (SCALE):
| Feature | Modified Ashworth Scale (MAS) | Modified Tardieu Scale (MTS) | Selective Control Assessment of the Lower Extremity (SCALE) |
|---|---|---|---|
| Purpose | Measures muscle spasticity | Evaluates muscle tone and spasticity | Assesses selective motor control in lower limbs |
| Primary Focus | Resistance to passive movement | Muscle tone at different velocities | Ability to isolate and control movements |
| Scoring System | 6-point scale (0 to 4) | Measures spasticity angle and velocity-dependent response | 0 to 2 for each joint (total score out of 10) |
| Assessment Method | Passive stretch of muscles | Passive movement at three different velocities (V1, V2, V3) | Active movement of joints in isolation |
| Velocity Factor | No velocity consideration | Assesses response at different velocities | No velocity consideration |
| Clinical Use | Quick and easy to administer | More detailed assessment of spasticity patterns | Evaluates motor control, particularly in cerebral palsy |
| Limitations | May not distinguish spasticity from stiffness | Requires more time and training to perform | Requires patient cooperation and active movement |
| Ideal Population | Neurological disorders (e.g., stroke, CP) | Children with CP, stroke patients | Children with cerebral palsy and motor control impairments |
| Pros | Simple, widely used, quick | More specific to spasticity, accounts for velocity | Assesses voluntary control, useful in therapy planning |
| Cons | Can be subjective, does not account for velocity | More complex, requires training | Limited to voluntary movements, may not assess passive issues |
Which one to use?
| Clinical Scenario | Best Tool to Use | Why |
|---|---|---|
| Assessing muscle spasticity | Modified Ashworth Scale (MAS) | Simple, quick, and effective for assessing resistance to passive movement, ideal for general spasticity measurement. |
| Assessing muscle tone and spasticity at different velocities | Modified Tardieu Scale (MTS) | Provides more detailed insights by considering muscle response at different speeds (V1, V2, V3), helping to assess velocity-dependent spasticity. |
| Assessing selective motor control in the lower limbs | Selective Control Assessment of the Lower Extremity (SCALE) | Best for evaluating the ability to isolate and control movements in the lower extremities, particularly in children with CP. |
| Quick initial assessment of spasticity in clinical settings | Modified Ashworth Scale (MAS) | Quick and easy to use, it’s ideal for fast screening in clinical environments. |
| Detailed assessment of spasticity and muscle tone dynamics | Modified Tardieu Scale (MTS) | Provides a more nuanced understanding of spasticity patterns, especially in cases where tone changes with velocity need to be understood. |
| Assessing the ability to perform isolated movements and voluntary control | Selective Control Assessment of the Lower Extremity (SCALE) | Focuses on selective motor control, making it essential for evaluating functional movement patterns in children with cerebral palsy. |
| When monitoring for progress in spasticity treatment | Modified Ashworth Scale (MAS) | Its simplicity and ability to track changes over time make it useful for monitoring improvements in spasticity. |
| When precise assessment of tone during rehabilitation is needed | Modified Tardieu Scale (MTS) | Provides detailed feedback on tone at different velocities, important for rehabilitation therapy planning. |
| Assessing joint mobility in children with cerebral palsy (CP) | Selective Control Assessment of the Lower Extremity (SCALE) | Specifically designed to assess functional motor control in CP, helping clinicians understand the child’s movement capacity. |
Summary:
- Use the MAS for general spasticity screening and quick assessments in clinical settings.
- Use the MTS if you need a more detailed analysis of muscle tone and spasticity, especially with respect to velocity-dependent spasticity.
- Use the SCALE when focusing on assessing voluntary, isolated movements and motor control, particularly in children with CP or other movement disorders.
Let me know if you’d like further clarification on any of the tools!