Cerebral palsy refers to a group of conditions that affect control of movement and posture. Due to damage to one or more parts of the brain that control movement, an affected person cannot move his or her muscles normally. Symptoms range from mild to severe, including forms of paralysis.
With treatment, most children can significantly improve their abilities. Although symptoms may change over time, cerebral palsy by definition is not progressive, so if increased impairment occurs, the problem may be something other than cerebral palsy.
Many children with cerebral palsy have other problems that require treatment. These include mental retardation; learning disabilities; seizures; and vision, hearing and speech problems.
Cerebral palsy usually is not diagnosed until a child is about 2 to 3 years of age. About 2 to 3 children in 1,000 over the age of three have cerebral palsy. About 500,000 children and adults of all ages in this country have cerebral palsy.
The three major types of cerebral palsy:
Spastic cerebral palsy. About 70 to 80 percent of affected individuals have spastic cerebral palsy, in which muscles are stiff, making movement difficult. When both legs are affected (spastic diplegia), a child may have difficulty walking because tight muscles in the hips and legs cause legs to turn inward and cross at the knees (called scissoring). In other cases, only one side of the body is affected (spastic hemiplegia), often with the arm more severely affected than the leg. Most severe is spastic quadriplegia, in which all four limbs and the trunk are affected, often along with the muscles controlling the mouth and tongue. Children with spastic quadriplegia have mental retardation and other problems.
Dyskinetic cerebral palsy. About 10 to 20 percent have the dyskinetic form, which affects the entire body. It is characterized by fluctuations in muscle tone (varying from too tight to too loose) and sometimes is associated with uncontrolled movements (which can be slow and writhing or rapid and jerky). Children often have trouble learning to control their bodies well enough to sit and walk. Because muscles of the face and tongue can be affected, there also can be difficulties with sucking, swallowing and speech.
Ataxic cerebral palsy. About 5 to 10 percent have the ataxic form, which affects balance and coordination. They may walk with an unsteady gait and have difficulty with motions that require precise coordination, such as writing.
There are many things that occur during pregnancy and around the time of birth that can disrupt the normal development of the brain and result in cerebral palsy. In about 70 percent of cases, brain damage occurs before birth, although it also occurs around the time of delivery, or in the first months or years of life.
Some of the known causes include:
Infections during pregnancy. Certain infections in the mother, including rubella (German measles), cytomegalovirus (a mild viral infection), and toxoplasmosis (a mild parasitic infection) can cause brain damage and result in cerebral palsy.
Insufficient oxygen reaching the fetus. For example, when the placenta is not functioning properly or it tears away from the wall of the uterus before delivery, the fetus may not receive sufficient oxygen.
Prematurity. Premature babies who weigh less than 3 1/3 pounds are up to 30 times more likely to develop cerebral palsy than full-term babies.
Complications of labor and delivery. Until recently, doctors believed that asphyxia (lack of oxygen) during a difficult delivery was the cause of most cases of cerebral palsy. Recent studies show that this causes only about 10 percent of cases.
Rh disease. This incompatibility between the blood of the mother and her fetus can cause brain damage, resulting in cerebral palsy. Fortunately, Rh disease usually can be prevented by giving an Rh-negative woman an injection of a blood product called Rh immune globulin around the 28th week of pregnancy and again after the birth of an Rh-positive baby.
Other birth defects. Babies with brain malformations, numerous genetic diseases, chromosomal abnormalities, and other physical birth defects are at increased risk of cerebral palsy.
Acquired cerebral palsy. About 10 percent of children with cerebral palsy acquire it after birth due to brain injuries that occur during the first two years of life. The most common causes of such injuries are brain infections (such as meningitis) and head injuries.
Cerebral palsy is diagnosed mainly by evaluating how a baby or young child moves. Some children with CP have low muscle tone, which can make them appear floppy. Others have increased muscle tone, which makes them appear stiff, or variable muscle tone (increased at times and low at other times).
The doctor also may suggest brain-imaging tests such as magnetic resonance imaging (MRI), computed tomography (CT scan), or ultrasound. These tests sometimes can help identify the cause of cerebral palsy.
How is cerebral palsy treated?
A team of health care professionals works with the child and family to identify the child’s needs. The team may include pediatricians, physical medicine and rehabilitation physicians, orthopedic surgeons, physical and occupational therapists, ophthalmologists, speech/language pathologists, and social workers and psychologists.
The child usually begins physical therapy soon after diagnosis. This enhances motor skills (such as sitting and walking), improves muscle strength, and helps prevent contractures (shortening of muscles that limits joint movement). Sometimes braces, splints or casts are used along with therapy to help prevent contractures and improve function of the hands or legs. If contractures are severe, surgery may be recommended to lengthen affected muscles.
Drugs may be used to ease spasticity or to reduce abnormal movement. Unfortunately, oral drug treatment is often not very helpful. Sometimes injection of drugs directly into spastic muscles is more helpful, and the effects may last several months. A new type of drug treatment is showing promise in children with moderate to severe spasticity affecting all four limbs. During a surgical procedure, a pump is implanted under the skin that continuously delivers the anti-spasmodic drug baclofen.
For some children with spasticity affecting both legs, selective dorsal rhizotomy may permanently reduce spasticity and improve the ability to sit, stand and walk. In this procedure, doctors cut some of the nerve fibers that are contributing most to spasticity. This procedure usually is done when a child is between 2 and 6 years of age.
Research suggests that cerebral palsy results from incorrect cell development early in pregnancy. For example, a group of researchers has recently observed that more than one-third of children with cerebral palsy also have missing enamel on certain teeth. Scientists are also examining other events -- such as bleeding in the brain, seizures, and breathing and circulation problems -- that threaten the brain of a newborn baby. Some investigators are conducting studies to learn whether certain drugs can help prevent neonatal stroke, and other investigators are examining the causes of low birth-weight. Other scientists are exploring how brain insults (like brain damage from a shortage of oxygen or blood flow, bleeding in the brain, and seizures) can cause the abnormal release of brain chemicals and trigger brain disease.
United Cerebral Palsy, March of Dimes, National Institute of Neurological Disorders and Stroke.