CLASSIFICATION OF CEREBRAL PALSY – what does it tell us?

The clinical features of cerebral palsy are diverse and include a wide range of abnormalities. Cerebral palsy is classified according to the main type of movement disorder that is present. Depending on which areas of the brain are affected, one or more of the following movement disorders may occur: stiff muscles (spasticity), uncontrolled movements (dyskinesia) or poor balance and coordination (ataxia). The benefit of using a classification system for children with cerebral palsy is to provide a common language for a quick presentation of the clinical picture of the child’s functional abilities. This is important for developing a therapeutic plan that will help the child reach his full potential.

TL;DR – the highlights:

• cerebral palsy is a complex disorder with a broad group of symptoms and disabilities
• depending on the type of movement disorder, CP is classified as spastic, dyskinetic and ataxic
• based on the area of presentation, it can be classified into involvement in one side or both sides of the body – diplegic CP is the most common type
• children can be classified according to gross motor function, manual ability, communication skills, and eating and drinking abilities
• classifying children with CP gives us a clear picture of their actual level of functioning

Types of cerebral palsy

The complexity of the syndrome is evident from its various classifications. Cerebral palsy (CP) can be defined according to the motor type, the topography of the motor impairment, or according to the degree of functional impairment. It can also be defined according to the anatomical site of the brain lesion (cerebral cortex, pyramidal tract, extrapyramidal system, or cerebellum). Based on the predominant type of tone or movement abnormality, we distinguish four types of CP: spastic (stiff muscles), dyskinetic (uncontrolled movements), ataxic (poor balance and coordination) and mixed. In terms of topographical involvement of extremities, we distinguish hemiplegia, diplegia or quadriplegia.

1. Spastic cerebral palsy: Spastic CP is the most common type of cerebral palsy, accounting for 80 to 90% of all cases. Spastic CP causes increased muscle tone, muscles stiffness, and difficulty walking. It’s also characterized by pathological reflexes (hyperreflexia) and mass movements instead of fine and individual movements.^1,2 Spastic CP affects the motor cortex, a specific part of the cerebral cortex responsible for planning and completing voluntary movement.
2. Dyskinetic cerebral palsy: Dyskinetic CP accounts for 10 to 20% of CP cases and manifests as involuntary, uncontrolled, repetitive and sometimes stereotyped movements with fluctuating muscle tone.^1,2 It’s an extrapyramidal form of CP and is primarily associated with damage to the basal ganglia.³ There are three distinctive features of dyskinetic CP. Dystonia involves involuntary muscle contractions characterized by twisting, slow and repetitive movements that worsen when the child begins to move, resulting in stiffness of movements. Athetosis involves abnormal muscle contractions that cause slow, involuntary writhing movements. Chorea is characterized by irregular, unpredictable jerky movements that are uncoordinated.^1,2
3. Ataxic cerebral palsy: Ataxic CP comprises 5-10% of CP cases and presents with loss of coordination, hypotonia, tremors and shaky movements that are difficult to control. It affects balance and depth perception. Children with ataxic CP often walk unsteadily with a wide base. They have trouble making quick or precise movements, such as writing or buttoning a shirt, or difficulty controlling voluntary movements, such as reaching for a toy.^1,2 Ataxic CP results from damage to the cerebellum, which is essential for coordinating muscle movements and balance.⁴
4. Mixed cerebral palsy: Mixed CP causes symptoms that do not correspond to any single type of CP but are characteristic of two or three other types. Spastic-dyskinetic CP is the most common type of mixed CP.^1,2

These classifications reflect the damaged areas of the brain. Pyramidal lesions are most clearly associated with spasticity, hypertonia, and increased reflexes. Extrapyramidal lesions are often associated with choreoathetosis and dyskinesias (and other forms of abnormal tone regulation), abnormal postural control, and coordination disorders.⁵

Depending on the area of ​​presentation, it can be classified as affecting one side (unilateral) or both sides of the body (bilateral), with diplegia being the most common, followed by hemiplegia (20-30%) and tetraplegia (also known as quadriplegia, 10-15%). The term hemiplegia generally refers to the impairment of one side of the body. Diplegia refers to the involvement of the lower limbs to a greater extent than the upper limbs, and tetraplegia refers to the involvement of all four limbs (although there may be differences in the severity of the involvement). It’s important to distinguish between unilateral and bilateral neuromotor involvement because treatment strategies may differ.^1,6

Dyskinesia, ataxia, and hypotonia usually affect all four limbs, while spasticity is categorized topographically. Children with spastic tetraplegia have severe motor impairments. Both upper and lower limbs are affected almost equally. In spastic hemiplegia, the arm is usually more affected than the leg.

Classifying cerebral palsy

Classification systems for children with CP describe the type of muscle tone and the number and distribution of the affected limbs. Several instruments have been developed to classify gross motor functions, manual skills, communication skills and eating and drinking abilities in children and adolescents with CP. It is important to recognize that cerebral palsy classification systems can be used together to reveal different aspects of a patient’s condition. In other words, they are not contradictory or mutually exclusive, and a child can be diagnosed using terms from different classification systems.

Children with CP can be characterized by how impaired their muscle tone is. The following terms are often used:

• Hypertonic cerebral palsy: Hypertonic or hypertonia refers to abnormally high muscle tone that creates muscle stiffness and rigidity. Spastic CP is characterized by hypertonia.
• Hypotonic cerebral palsy: Hypotonic or hypotonia refers to abnormally low muscle tone. Symptoms of hypotonia include floppiness and weakness.

Topographic and motor classifications don’t give a sense of functional abilities related to gross motor skills; this is an obvious advantage of functional classifications. The Gross Motor Function Classification System (GMFCS) is age-dependent and describes five groups based on the child’s functioning and mobility. Level I indicates that the person has minimal disability and level V indicates complete dependence on equipment or a caregiver to maintain posture. Levels are independent of cerebral palsy motor type and distribution. They don’t indicate the quality of movement but the child’s functional abilities.

In general, the five levels are described as follows:

• Level I: Functional abilities are quite good, although speed, balance, and coordination may be impaired. The child can move independently without help.
• Level II: The child can walk with limitations and may need assistance on inclined or uneven surfaces, but there is no need for the assistance of adaptive equipment.
• Level III: The child can walk using hand-held adaptive equipment but may need a wheelchair to move over inclined or uneven surfaces, or to travel long distances.
• Level IV: The child is self-mobile, but with significant limitations. Many of them use electric wheelchairs, need a lot of help with transfers, and are dependent on adaptive and assistive equipment.
• Level V: Voluntary movement is usually difficult, and the individual is extremely dependent on adaptive equipment, assistive technology, and help from other people for mobility.^7,8

The Manual Ability Classification System (MACS) categorizes CP based on an individual’s ability to handle objects during daily activities (e.g., playing, eating, or dressing), which is closely related to the individual’s ability to perform tasks independently. It considers how children use their hands together rather than separately. The MACS is used for children aged 4-18 years⁹, but recently it has been expanded and a new version of the MACS for children under 4 years (mini-MACS) has been developed.¹⁰ Like the GMFCS, the MACS is divided into five levels, with level five being the most severe:

• MACS Level I: The child handles objects with ease.
• MACS Level II: The child handles objects mostly successfully, but with reduced speed or quality.
• MACS Level III: The child has difficulty handling objects and often needs help preparing or modifying activities.
• MACS Level IV: The child can handle certain objects (with difficulty) but needs a lot of help from others.
• MACS Level V: The child has extremely limited ability to handle objects or complete even simple actions with their hands.⁹

The Communication Function Classification System (CFCS) categorizes individuals with CP and other disabilities based on everyday communication performance. Differences between levels of communication skills are based on performance, which addresses both sender and receiver abilities, the pace of communication, and the conversational pattern. When assigning a grade, the evaluator takes into account all the child’s communication modalities (e.g. verbal and non-verbal). As with the GMFCS and MACS, the CFCS has five levels of increasing severity.¹¹

• CFCS Level I: The child can effectively send and receive communicative information with unfamiliar and familiar communication partners.
• CFCS Level II: The child effectively, but slowly, sends and receives communicative information with both unfamiliar and familiar partners.
• CFCS Level III: The child is usually able to effectively send and receive communication information with familiar partners but may struggle to communicate with unfamiliar partners.
• CFCS Level IV: The child sends and receives communication information inconsistently with familiar partners and may rarely communicate with unfamiliar partners.
• CFCS Level V: The child rarely communicates effectively, even with familiar people.¹¹

The Eating and Drinking Abilities Classification System (EDACS) is again a five-level classification system used to evaluate a child’s eating and drinking safety (risk of aspiration or chocking) and eating and drinking efficiency (amount of food wasted, and time taken to eat). It has an additional three levels to help determine how much help a child needs to perform these activities and the need to adjust the texture of food and drink. It is used for children aged 3 years and above,¹² but recently a new version has been developed – the Mini-EDACS, which is suitable for very young children with CP aged 18 to 36 months.¹³

• EDACS Level I: The child can eat and drink safely without any help, but solid foods can cause swallowing problems.
• EDACS Level II: The child can eat and drink safely but with some limitations to efficiency. Mealtime will take longer than for peers.
• EDACS Level III: The child can eat and drink with some safety restrictions; there may be limitations to efficiency. The child can’t eat hard food but needs very soft and mashed food.
• EDACS Level IV: The child can eat and drink with significant safety restriction. The child may need special food textures, fluid consistency, techniques, positioning, and a modified environment to reduce the risk of aspiration and choking and increase efficiency.
• EDACS Level V: The child is unable to eat and drink safely – tube feeding may be considered to provide nutrition.¹²

	GMFCS	MACS	CFCS	EDACS
Level I	walks without limitations	handles objects without limitations	communicates effectively without limitation	eats and drinks safely and efficiently
Level II	walks with limitations	handles most objects but with limitations	may require additional time to communicate effectively	eats and drinks safely, but with some efficiency limitations
Level III	walks with hand-held device	handles objects with difficulty	communicates effectively with familiar people	eats and drinks with some safety limitations, and with efficiency limitations
Level IV	moves independently with limitations	handles limited easily managed objects	inconsistent communication, even with familiar people	significant limitations to eating and drinking safely
Level V	dependent on others for mobility	very severely limited in manual handling	rarely communicates effectively	unable to eat or drink safely

Classifying children with CP gives therapists, schools, and health professionals a clear picture of their actual level of functioning. It provides us with information about what to expect, what type of assistive technology a child may need, and how to encourage child’s full potential.

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