Classification of Cerebral Palsy Types
Cerebral palsy is broken down into several different types to describe how certain brain damage can affect overall motor skills. The classification of cerebral palsy depends on the type of movement issues and the affected body parts.
There are five major types of cerebral palsy: spastic, ataxic, athetoid, hypotonic, and mixed type.
The type of movement issues an individual with cerebral palsy experiences can depend on how severely their brain injury has affected their muscle tone. Muscle tone is the strength and tension of the muscles.
Cerebral Palsy Types
There are five different types of cerebral palsy. Here is a breakdown of how common each cerebral palsy type is:
Different Types of Cerebral Palsy
Spastic Cerebral Palsy
Spastic cerebral palsy is the most common type and accounts for 77% of all cases. Also referred to as hypertonic cerebral palsy, most individuals with this type experience high muscle tone and exaggerated, jerky movements (spasticity).
Spastic cerebral palsy is caused by damage to the brain’s motor cortex, which controls voluntary movement. It is also caused by damage to the pyramidal tracts, which help relay signals to the muscles. For this reason, this type of cerebral palsy is sometimes referred to as “pyramidal.”
The motor cortex is found on both sides of the brain, and the pyramidal tracts connect each side of the motor cortex to one another. Damage to the right side of the motor cortex causes movement problems on the left side of the body, and vice versa.
Common symptoms of spastic cerebral palsy include:
- Abnormal walking
- Awkward reflexes
- Contractures (permanently tightened muscles or joints)
- Stiffness in one part of the body
Ataxic Cerebral Palsy
Ataxic cerebral palsy makes up about 2.4% of all cerebral palsy cases. This type of cerebral palsy causes ataxia and issues with balance, coordination, and voluntary movement.
Ataxic cerebral palsy is caused by damage to the cerebellum, which is responsible for coordinating physical movement. Individuals with ataxic cerebral palsy often experience tremors and a reduction in muscle tone.
Common symptoms of ataxic cerebral palsy include:
- Poor coordination
- Problems with depth perception
- Shakiness and tremors
- Speech difficulties
- Spreading feet apart when walking
Athetoid Cerebral Palsy
About 2.6% of children with the condition are diagnosed with athetoid cerebral palsy (also known as non-spastic or dyskinetic cerebral palsy). This type causes issues with involuntary movement in the face, torso, and limbs.
Athetoid cerebral palsy is characterized by a combination of hypotonia (loosened muscles) and hypertonia (stiffened muscles) which causes muscle tone to fluctuate.
This type of cerebral palsy is caused by damage to the brain’s basal ganglia and/or cerebellum. The basal ganglia regulates voluntary motor function and eye movement, and the cerebellum controls balance and coordination.
Athetoid cerebral palsy is considered extrapyramidal. The extrapyramidal tracts in the brain regulate involuntary reflexes and movement signaled by the basal ganglia and cerebellum.
Common symptoms of athetoid cerebral palsy include:
- Feeding issues
- Floppiness in the limbs
- Problems with posture
- Stiff or rigid body
Hypotonic Cerebral Palsy
Hypotonic cerebral palsy (also known as atonic cerebral palsy) makes up about 2.6% of all cases. This cerebral palsy type is classified by low muscle tone that causes loss of strength and firmness, resulting in floppy muscles.
Instability and floppiness in muscles caused by hypotonic cerebral palsy can cause a child to miss developmental milestones such as crawling, standing, or walking.
Common symptoms of hypotonic cerebral palsy include:
- Flexible joints and ligaments
- Lack of head control
- Loose muscles
- Poor balance and stability
Mixed Type Cerebral Palsy
In some cases, damage to the developing brain is not confined to one location. It is possible for a child to develop more than one type of cerebral palsy caused by damage to several areas of the brain.
Mixed type cerebral palsy occurs when a child is showing symptoms of two or more types of cerebral palsy. About 15.4% of all cases are diagnosed as mixed type cerebral palsy.
The most common mixed cerebral palsy diagnosis is a combination of spastic and athetoid cerebral palsy, since both of these types are characterized by issues with involuntary movement.
Types of Movement Problems
Types of cerebral palsy are diagnosed by the type of brain injury and movement problem. For example, a diagnosis of cerebral palsy may be “spastic diplegia” or “athetoid quadriplegia.” The location of movement problems is related to the location of a brain injury and can determine which type of cerebral palsy your child has.
- Monoplegia is a very rare type of movement problem that occurs when only one arm or leg is affected.
- Diplegia affects two limbs, which most commonly are the legs. Children with diplegia may have mild movement issues in the upper body as well. Diplegia is commonly a result of premature birth that results in cerebral palsy.
- Hemiplegia affects one entire side of the body. The arm is generally more affected than the leg and is distinguished by a rigidly flexed wrist or elbow. Prenatal brain bleeding can lead to hemiplegia.
- Triplegia occurs when three limbs are affected. This may occur if both legs and one arm cannot move freely.
- Quadriplegia occurs when all four limbs are affected. The legs are generally impacted more than the arms. Quadriplegia may cause limited control over facial muscles.
- Double hemiplegia occurs when all four limbs are affected, but one side is affected more than the other.
Gross Motor Function Classification System
The Gross Motor Function Classification System (GMFCS) is a tool used to determine the type of cerebral palsy a child may have. Each type of cerebral palsy affects muscle tone in different ways.
The GMFCS consists of five levels that provide a better understanding of a child’s overall motor function and can help to determine future treatment to improve the child’s quality of life. The GMFCS scale can help specialists determine which mobility aids may be necessary to assist movement.
Specialists will examine a child’s gross motor skills, such as sitting and walking, to determine which GMFCS level they are on to accurately diagnose the cerebral palsy type.
According to the Cerebral Palsy Alliance, a child over five years of age that ranks at Level IV (extreme motor function impairment) on the GMFCS scale will generally not improve their level and will more than likely use a mobility device throughout their life.
Learn More About Types of Cerebral Palsy
Consulting with a cerebral palsy specialist is the best way to get an accurate diagnosis for your child’s type of cerebral palsy. If you have more questions about cerebral palsy types, download our free cerebral palsy guide today to learn more.
Cerebral Palsy Types FAQs
What are the different types of cerebral palsy?
There are five different types of cerebral palsy – spastic, ataxic, athetoid, hypotonic, and mixed type cerebral palsy.
Each type is classified by a unique set of cerebral palsy symptoms. It is possible for children to show symptoms of more than one type of cerebral palsy. These cases are considered mixed type cerebral palsy.
How do doctors determine which type of cerebral palsy my child has?
Cerebral palsy specialists will use the Gross Motor Function Classification System (GMFCS) to determine which type of cerebral palsy your child may have.
The GMFCS is a five-level ranking system that determines the type of cerebral palsy a child has by examining overall motor function. Early medical intervention before the age of 5 can help improve your child’s GMFCS level and overall mobility.
What is the most severe form of cerebral palsy?
According to the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the most severe form of cerebral palsy is spastic quadriplegia.
Spastic quadriplegia involves severe hypertonia of the arms and legs and a floppy neck. Children with spastic quadriplegia are unable to walk and often have speech difficulties. Spastic quadriplegia patients may also experience moderate to severe intellectual and developmental disabilities (IDD).