Cerebral palsy is the result of an injury to the parts of the brain that control muscle tone. It occurs at or before birth or before the age of 2. Depending on where the injury occurs in the brain, and how big it is, muscles can be too tight, too loose or a combination of both. Muscle tone allows people to keep their bodies in a specific position, such as sitting or standing. There are four types of cerebral palsy.
Spastic
Spastic cerebral palsy is the medical term used to describe muscle tone that is too stiff. According to the National Institute of Neurological Disorders and Stroke, spasticity can affect one side of the body, just the legs or arms or all four limbs. When spasticity affects one side it is called spastic hemiplegia; when it affects just the legs it is called spastic diplegia; and when it affects all four limbs it is called spastic quadriplegia. People with hemiplegia or diplegia often have normal intelligence but may have difficulty with speech. People with hemiplegia and quadriplegia can develop an abnormal curvature of the spine as they grow to adulthood because of the forces placed on the spine by increased muscle tone. People with spastic quadriplegia have the most difficulty with speech, have a higher risk of mental retardation and may also experience seizure activity.
Ataxic
According to the University of Virginia School of Medicine, people with the ataxic form of cerebral palsy have low muscle tone resulting in poor coordination throughout their bodies. These people look unsteady and shaky, and the movements may resemble those seen in an elderly person. Because of their low muscle tone and poor coordination, individuals with ataxic cerebral palsy are unable to perform fine motor skills, such as writing or cutting with scissors. They may also have poor balance and difficulty walking.
Athetoid
According to Kids Health, children and adults with athetoid cerebral palsy have difficulty controlling the muscles in their body. As a result, their arms, legs and sometimes neck muscles can flutter or move suddenly. Some individuals experience writhing movements in their legs and arms. When these types of movements affect the neck muscles, they can cause degeneration of the discs in the spinal cord over time. In some individuals the movements can affect facial muscles, which causes drooling. According to the University of Virginia School of Medicine, approximately 25 percent of all people with cerebral palsy have athetoid cerebral palsy. This type of cerebral palsy rarely affects intelligence.
Mixed
At least two types of muscle tone commonly present in individuals with cerebral palsy. The National Institute of Neurological Disorders and Stroke explains that this diagnosis is mixed-type cerebral palsy. Most commonly it is a mixture of spasticity and ataxic types of cerebral palsy, meaning that a person has some muscles that are too tight and others that are too relaxed. This situation creates a mixture of stiffness in some parts of the body and floppiness in others.
