Exploring the Different Types of Cerebral Palsy: Spastic, Athetoid, Ataxic, and Mixed

Cerebral palsy (CP) is not a single, uniform condition – it’s a group of neurological disorders caused by damage to the developing brain, typically before, during, or shortly after birth. According to the National Institute of Neurological Disorders and Stroke (NINDS), CP permanently affects body movement and muscle coordination, and is the leading cause of childhood disability in the United States. One of the most important things to understand about CP is that it presents differently in every child. To make sense of this variation, clinicians classify cerebral palsy using two key frameworks: which parts of the body are affected, and what kind of muscle tone disorder is present. Together, these two dimensions explain the distinct types – spastic, athetoid, ataxic, and mixed – and why each child’s experience of CP can look so different.

How cerebral palsy is classified 🔗

Cerebral palsy classification works along two axes. The first looks at the topography – the body parts affected by the movement disorder. The second examines the quality of muscle tone, which determines the type of movement problem the child experiences.

Classification by body parts affected 🔗

According to the Cerebral Palsy Research Network, clinicians describe which body regions are involved using specific terms. Hemiplegia refers to CP that affects one side of the body – typically the arm more than the leg. Diplegia primarily affects the lower half of the body, with the legs more significantly impacted than the arms. Quadriplegia involves all four limbs, as well as the trunk, face, and mouth muscles. More recently, some clinicians have moved toward using the broader terms unilateral CP (one side affected) and bilateral CP (both sides affected) to replace these older labels, though both sets of terms remain in use.

Classification by muscle tone: hypertonia and hypotonia 🔗

Muscle tone is the baseline tension in a muscle – the natural resistance it provides even at rest. Flint Rehab explains that in cerebral palsy, damage to the brain disrupts the signals sent to the muscles, leading to abnormal muscle tone. This can go in one of two directions.

Hypertonia means the muscle tone is higher than normal. The muscles are overly tight, stiff, and resistant to movement. As noted by Cerebral Palsy Guidance, the most common form of hypertonia in CP is spasticity – where stiff muscles produce jerky, exaggerated movements. Hypotonia, on the other hand, means the muscle tone is too low. The muscles feel floppy and loose, making it hard for a child to maintain posture, hold their head up, or sit steadily. The NINDS notes that decreased muscle tone can make infants with CP appear relaxed or even limp, while increased tone makes bodies seem stiff or rigid. Both extremes disrupt the smooth, coordinated movement that the brain and muscles normally produce together.

With this foundation in place, we can now look at each type of CP and the specific movement disorder it produces.

Spastic cerebral palsy: stiff and difficult movements 🔗

Spastic CP is by far the most common type. Cerebral Palsy Guide reports that it accounts for approximately 77-80% of all CP cases. It results from damage to the cerebral cortex – the outer layer of the brain responsible for voluntary movement. This damage causes persistent hypertonia: the muscles stay in a state of high tension, resisting movement and limiting range of motion.

As described by Robins Kaplan LLP, the constant increased muscle tone creates tightness in the muscles and leads to a reduced range of movement in the joints. Movements are slow, effortful, and uncoordinated. In more severe cases, a child may stiffen suddenly when startled or when attempting to stand, and the legs may cross at the knees – a posture often called a scissoring gait.

Spastic CP is further divided by which parts of the body are involved:

• Spastic diplegia – primarily affects the legs. Children often walk with a scissoring or crouched gait. Intelligence is usually typical.
• Spastic hemiplegia – affects one side of the body, usually the arm more than the leg. Most children can walk, though the affected limbs may develop bone deformities or shortened muscles over time.
• Spastic quadriplegia – the most severe form, affecting all four limbs and often the trunk and face. Children typically cannot walk independently and may have associated conditions including seizures, speech difficulties, and intellectual disability.

Athetoid cerebral palsy: involuntary and uncontrolled movements 🔗

Athetoid CP – also called dyskinetic cerebral palsy – is the second most common type. According to NCBI’s StatPearls (NIH), it comprises around 12-14% of all CP cases and results from brain injury during late pregnancy or early birth that affects the basal ganglia – the area of the brain responsible for regulating smooth, coordinated movement and posture.

Unlike spastic CP, athetoid CP involves fluctuating muscle tone – some muscles are too tense while others are too relaxed, and this can shift unpredictably. The defining feature is involuntary, uncontrolled movements: slow, writhing, or wriggly motions that the child cannot suppress. These movements most commonly affect the hands, feet, arms, and legs. As described by Robins Kaplan, the movements can also affect the muscles of the face and tongue, causing grimacing, drooling, or unusual facial expressions.

Because the child is constantly battling involuntary movement, maintaining a stable, upright position is very difficult. This interferes with everyday functions: speaking, eating, reaching for objects, and walking all require the very postural control that athetosis disrupts. One notable feature – as documented in NIH’s StatPearls – is that these involuntary movements often diminish or disappear completely during sleep, but tend to intensify during periods of emotional stress or heightened effort.

Ataxic cerebral palsy: unsteady and shaky movements 🔗

Ataxic CP is the least common of the main types, affecting between 2-10% of people with CP, depending on the source. It results from damage to the cerebellum – the part of the brain at the base of the skull that coordinates balance, posture, and precision in movement. Unlike the other types, ataxic CP is characterized by hypotonia (low muscle tone) combined with poor coordination.

Children with ataxic CP do not typically have involuntary movements when sitting still. Instead, as explained by Robins Kaplan, their intentional movements are clumsy, awkward, or poorly judged – muscles tend to overshoot or undershoot a target. The Cerebral Palsy Research Network describes the hallmark as wobbly, shaky purposeful movements – tremors that occur specifically when the child tries to move, rather than at rest.

Balance is significantly affected. To compensate, children often walk with a wide-based gait – spreading their feet apart to stabilize themselves and reduce the risk of falling. Depth perception is also commonly impaired, which affects the child’s ability to judge distances accurately. Fine motor tasks that require precise hand-eye coordination – such as writing, buttoning a shirt, or catching a falling object – are particularly challenging. UCLA Health notes that this form of impaired motor control causes movement to occur synergistically, meaning motion at one joint cannot always occur independently of another.

Mixed type cerebral palsy: a combination of symptoms 🔗

When brain injury occurs in more than one area, a child may exhibit features of multiple CP types simultaneously. This is called mixed cerebral palsy. According to the NINDS, mixed CP occurs when symptoms do not fit neatly into a single type but instead represent a blend.

The most common combination, as documented by both the Cerebral Palsy Research Network and Cerebral Palsy Guidance, is spastic and dyskinetic (athetoid) CP together – where a child has both the stiff, high-tone muscles of spastic CP and the involuntary movements of athetoid CP. Other combinations are possible, including spastic with ataxic features, though the athetoid-ataxic combination is the least common. In some cases, a child may show signs of all three types.

Mixed CP often results in more complex functional challenges and may be associated with additional medical conditions such as epilepsy, speech disorders, and musculoskeletal deformities. Birth Injury Center notes that symptoms in mixed CP vary widely depending on which types are combined and how severely each is expressed – making individualized assessment and treatment planning especially important.

Why understanding CP types matters 🔗

Understanding the type of cerebral palsy a child has is not just a clinical exercise – it directly shapes the support, therapy, and educational accommodations the child will need. A child with spastic diplegia may need physical therapy targeting lower limb mobility and walking aids. A child with athetoid CP may need communication support, adapted feeding equipment, and strategies to manage involuntary movements during learning tasks. A child with ataxic CP may need support with fine motor skills, balance training, and additional time for tasks requiring precision.

As the Cerebral Palsy Research Network points out, the term “cerebral palsy” alone offers little information about what daily challenges a person actually faces. A thorough understanding of the specific movement disorder, the muscle tone involved, and the body parts affected is what enables teachers, therapists, and caregivers to make meaningful, targeted decisions that genuinely improve a child’s quality of life and participation in learning.

What do you think? If you work with or support a child with cerebral palsy, how does knowing the specific type of CP shape the way you approach their learning environment or daily activities? And considering how differently each type presents – from the stiffness of spastic CP to the shakiness of ataxic CP – what challenges do you think educators face when trying to provide inclusive, responsive support in the classroom?

References

1. https://www.ninds.nih.gov/health-information/disorders/cerebral-palsy
2. https://cprn.org/types-of-cerebral-palsy/
3. https://www.flintrehab.com/cerebral-palsy-muscle-tone/
4. https://cerebralpalsyguidance.com/cerebral-palsy/types/hypertonic/
5. https://www.cerebralpalsyguide.com/cerebral-palsy/types/
6. https://www.robinskaplan.com/services/medical-malpractice-attorneys/cerebral-palsy/what-are-the-different-types-of-cerebral-palsy
7. https://www.ncbi.nlm.nih.gov/books/NBK563160/
8. https://www.uclahealth.org/medical-services/orthopedics-and-sports-medicine/cerebral-palsy/what-cp/clinical-features
9. https://cerebralpalsyguidance.com/cerebral-palsy/types/
10. https://birthinjurycenter.org/cerebral-palsy/types/