General Information about Cerebral Palsy and Types of Cerebral Palsy

Cerebral Palsy (CP) is a group of disorders whose major feature is brain damage.Most of the time this damage is done before/during or shortly after birth and can be due to a variety of causes.Cerebral Palsy can be caused by a brain injury that would occur due to a fall down stairs or car accident, however when this is the cause it is more commonly called Traumatic Brain Injury when the event occurs after age 3 years not Cerebral Palsy although it is the same thing.

Other Terms for Cerebral PalsyDevelopmentally Delayed/disabled

  • Traumatic Brain Injury
  • Stroke or Cerebral Vascular Accident (CVA)
  • Little's Disease
  • Infantile Cerebral Paralysis
  • Dyskinetic cerebral palsy or Dystonia (Athetoid CP)

There are four types of CP: Spastic, Athetoid, Ataxic, and Mixed. Spastic (hypertonic) CP is characterized by tight muscles. In Athetoid (dyskinetic, hypotonic, dystonia) CP involuntary movements are present. Ataxic CP occur when the Cerebellum has been damaged, thus causing lack of coordination and jerky movements.Spastic CP is the most common type of Cerebral Palsy and in present in about 50% (depending on who’s statistics you use) of people with CP.Spastic CP may also be called Hypertonic Cerebral palsy because there is in essence and over abundance of muscle tone.It can be subdivided into 5 types, two of which are extremely rear and will only be mentioned here casually so that you may have a complete understanding of Cerebral Palsy

Sub classification of Spastic Cerebral Palsy by Geographic Origin

  • Diplegic - affects either booth arms or booth legs
  • Hemiplegia- affecting the limbs on only one side of the body
  • Quadriplegia- affecting all the limbs
  • Monoplegia* - affecting only one limb
  • Triplegia*- affecting three limbs

In people with spastic cerebral palsy you often find tight muscles.It is common, although not the rule, for persons with spastic CP to have a learning disability or mental retardation.This is certainly not true in all cases, and you will find learning disability and MR in other types of cerebral palsy as well. MR is the exception--not the rule and is found in approximately 50% of those with spastic CP and 35-40% of the total cerebral palsy population.

Athetoid or Dyskinetic CP 

In persons with this type of CP unintentional or uncontrolled movements will often be seen. This is due to an ever changing level of muscle tone. This type of CP accounts for up to 30% of all persons with CP depending on who’s statistics you use. In this type of cerebral palsy the basil ganglia (a part of the brain) has been damaged, or there may be what is termed wide spread brain damage.Sub classifications as used in Spastic CP do not hold up when talking about Athetoid CP except for that of Quadriplegia or total body involvement for the most part however there may be exceptions to this statement. For the most part athetosis usually affects the entire body to some extent and because of the constant fluctuation in muscle tone it may be called Hypotonic Quadriplegia. It has been noted that a large percent of persons with athetosis have above average intelligence.

This, the second most common type of cerebral palsy is a group of disorders who’s clinical name is dyskinetic cerebral palsy but they are more commonly referred to as Athetoid cerebral palsy. The dyskinetic cerebral palsy group consists of the following movement disorders based on the type of movement disorder and/or abnormal posturing:

  • Athetosis
  • Tremor
  • Dystonia
  • Choreiform
  • Rigidity

Athetoid or dyskinetic cerebral palsy should not be confused with the type of dystonia that has adult onset and is degenerative. Athetoid CP is not degenerative in nature.

Ataxic CP is characterized by a lack of coordination and balance due to damage to the cerebellum. This type of CP accounts for 10% of all cases of CP. As with athetosis, the sub classifications of spastic CP do not apply as readily here.

Ataxic Cerebral Palsy should not be confused with other forms of ataxia such as those that are inherited. Ataxic CP is completely unrelated to the disease process present in the inherited forms of ataxia (i.e. FA). Ataxic CP is not degenerative in nature.  

Mixed CP occurs when two or more types of CP are present in the same person. For example the author of this web page has Athetoid and Ataxic CP. The most common type of mixed cp would be Athetoid/Spastic-diplegic or Athetoid/Spastic-hemiplegic. The least common type of mixed CP would be Athetoid/Ataxic. However, any mix of types and subtypes discussed above may occur. It is even possible to have a mix of all three types (Spastic/Athetoid/Ataxic). Statistics will say that mixed CP accounts for 10% of all cases of cerebral palsy, but the actual percentage may be more. The incidence of mixed cerebral palsy has been rising due to better diagnostic techniques.

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This page was last updated 06/24/00