Types of Cerebral Palsy
The term cerebral palsy covers several different types of related movement disorders. The symptoms affect people differently including the part of the body that are affected and to what degree. As a result, saying someone has cerebral palsy offers little information about what challenges they do or do not face in their daily life. It also does not offer clarity about the types of treatments that may or may not be helpful.
This is important information to consider when working with doctors and others who are less familiar with CP. How an individual's motor function and daily life is affected by cerebral palsy requires discussion and evaluation. It is important to keep in mind that the initial disturbance in the brain's early development may also have affected other parts of the brain that control other functions beyond motor control (discussed later in the Tool Kit).
Below are the most common types of CP based on the European Classifications of CP which is the most widely accepted standard for discussing cerebral palsy. These types of cerebral palsy highlight the primary movement disorder that is interfering with the individual's motor control and function. The type of CP may refer to abnormal muscle tone, involuntary movements, or both. There may also be other symptoms or other types of abnormal muscle tone that are observed and interfere with the individual's daily activities. For example, people with spastic forms of CP may also have some areas of the body that are hypotonic or "floppy."Spastic
The majority of individuals with CP have the spastic form. In spastic CP the individual has abnormal muscle tone and the muscles are stiff, making movement difficult. Spastic cerebral palsy can affect specific parts of the body leaving the remaining parts unaffected or much less affected (whereas other types of CP typically affect the entire body). You may hear clinicians use the following terms that identify which parts of the body have spasticity:
- Hemiplegia: mostly one side of the body is affected
- Diplegia: mostly the lower half of the body is affected
- Quadriplegia: all four limbs are affected. The muscles of the trunk, face, and mouth can also be affected.
These terms are often confusing because how CP affects different parts of the body can change daily and doctors may interpret presentations differently. Recently more researchers and clinicians have begun using the terms bilateral (affecting both sides-bi = two) and unilateral (affecting one side-uni = one) to replace the above terms in order to more generally, and perhaps more accurately describe an individual's presentation. What terms you hear depends on the preference of the physician and therapy professionals you meet.
One clinician may use diplegia to describe an individual who has less impairment on the upper half compared with the lower half of the body, even though all four limbs are affected. This can cause confusion about how to direct treatment because a diagnosis of diplegic CP may convey that the upper part of the body does not require support or treatment. Another clinician may look at the same child, recognize this problem, and provide a diagnosis of quadriplegia.Dyskinetic
About 10 to 20 percent have this form of CP. Dyskinetic CP is an umbrella term characterized by three different types of involuntary movements including dystonic, athetoid, and choreic (but the individual does not have to have all of them). These disorders of movement often involve the entire body and are particularly noticeable when the person begins to move, but may also occur at rest. Individuals who have dyskinetic movements often have spasticity too. In these cases where two or more types of CP (i.e., spastic and dyskinetic) are seen together, the individual is considered to have a mixed form of CP. There are 3 distinct types of movement disorders typically caused by dyskentic CP:Dystonia: dystonia is characterized by intermittent or lengthy muscle contractions that lead to twisting and repetitive movement sequences, abnormal posture or both. Dystonic postures are often triggered by attempts at voluntary movement. Dystonia can be present in one part of the body, known as focal dystonia, seen during specific tasks or postures, known as task-specific dystonia, or throughout the whole body, known as generalized dystonia.Athetosis: People who have athetoid movements experience slow, continuous, involuntary twisting movements that prevent stable posture. The parts of the body that make up these movements are the same each time (unlike choreiform movements where the parts of the body involved may change). The term "athetosis" comes from the Greek word meaning "without position or place" which refers to the person's inability to keep a stable posture.Chorea: Characterised by a sequence of one or more involuntary movements that are abrupt and appear irregular. Unlike dystonic movements choreiform movements look more rapid, unpredictable, and ongoing. People with mild chorea may appear fidgety or clumsy, while those with more severe chorea have larger, more noticeable movements. Choreic movements may appear to flow randomly from one muscle group to another and may involve the trunk, neck, face, tongue, legs and arms. They may also occur with athetosis, referred to as choreoathetosis, or they may also occur with dystonic movements (see diagram to the left). Choreic movements subside during sleep.Ataxic
About 1 to 10 percent of people with CP have the ataxic form. Ataxic CP is caused by damage to the balance centers of the brain and individuals may have problems with balance, depth perception and coordination. It is often characterized by wobbly or shaky purposeful movements (occurring with the intention to move), difficulty with muscles overshooting or undershooting to meet a specific target, and may also involve difficulty coordinating precise finger movements for fine motor skills such as writing or using utensils. The word "ataxia", comes from the Greek word, "a taxis" meaning "without order or lacking coordination." Ataxia may affect any part of the body and may lead to problems with speech, swallowing and coordinating eye movements.Mixed
These individuals present with symptoms of more than one of the previous three forms of CP. The most common mixed form includes spasticity and dyskinetic movements but other combinations are also possible.
After learning what type of CP your child has, understanding more about individual functional abilities and support needs often provides the most meaningful information for how to direct therapy and other medical interventions. The Gross Motor Function and Classification Scale, or GMFCS, is a tool often administered by a developmental pediatrician or a physical therapist. It is designed to describe an individual's present ability to move and their need for supportive devices.
In addition to this and other professional assessments, it is also very important for you to share your insight about what you or other caregivers notice about your child's movement. The people who spend the most time with your child may notice important subtleties about how your child moves which can help your team of physicians and therapy professionals determine the most effective treatment plans.Supporting Literature
- Winter et al., Trends in the Prevalence of Cerebral Palsy in a Population Based Study, 110 Pediatrics 1220 (2002).
- Himmelmann et al., The Changing Panorama of Cerebral Palsy in Sweden, IX: Prevalence and Origin in the Birth-Year Period 1995 - 1998, 94 Acts Paediatrica 287 (2005).
- Nelson, et al., "Potentially Asphyxiating Conditions and Spastic Cerebral Palsy in Infants of Normal Birth Weight", Am J Obstet Gynecol, 1998, 179(2), 507-13.