Roughly 500,000 people in the United States have cerebral palsy. It is one of the most common of all congenital (present at birth) disorders: In the United States 15-20 cases are seen in every 10,000 births.
Children who eventually develop cerebral palsy experience injury to their central nervous system sometime before birth or at birth. This injury causes changes in the structure of the infant's brain. We call the changes "static encephalopathy" (encephalopathy means "brain disease") because they seem to stop right after birth. It is the physical effects caused by the injury, such as muscle spasticity and inability to walk, that family and healthcare workers need to be aware of as the child grows up. There may also be neurological side effects like seizures (epilepsy).
Cerebral palsy can be caused by something that happens
Before delivery (the most common time): such as infection, stroke, and metabolic problems such as diabetes and hyperthyroidism.
During delivery: such as not enough oxygen reaching the fetus.
Just after birth: such as a stroke or an infection in the baby.
Some children with cerebral palsy are born early or with obvious signs of infection, but in many cases the cause of brain injury is unknown.
Cerebral palsy symptoms include unusually weak or tight muscles, difficulty with balance, poor coordination, abnormal reflexes, and delay in developing motor skills such as sitting and walking. The diagnosis refers exclusively to problems with movement, but the underlying brain injury may cause other neurological problems. About half of children with cerebral palsy will also develop seizures, and about one-quarter will have severe mental retardation. Some of these symptoms may take time to become obvious, especially since cases of cerebral palsy can range from severe to mild and almost unnoticeable.
The brain injuries that cause cerebral palsy get no worse over time, but the symptoms may develop and change over time. For example, weak muscles often result in what are known as joint contractures -- permanent bending away from the normal position of the joint -- as the child grows. But at the same time, the child's brain continues to develop, and other symptoms may improve.
"The child's brain and nervous system continue to mature and grow over the first several years of life," according to Dr. David Roye, chief of the Division of Pediatric Orthopedics at Columbia Presbyterian Medical Center in New York City. "It is really gratifying to watch the impressive gains the child with CP can make over time."
Cerebral palsy is sometimes diagnosed at birth, or the diagnosis may not be made until a child is 2 or 3 years old. Physicians use a number of clinical tests to make the diagnosis: No one blood test or X-ray can detect this condition. The physician will test the strength of various muscles, assess the range of motion of different joints, and compare the child's physical and intellectual development with normal childhood milestones.
Before diagnosing a child with cerebral palsy, the physician may also order lab tests to rule out other causes for the developmental delay (like Tay-Sachs disease or leukodystrophy).
The awkward configurations of muscles in children with cerebral palsy can cause problems with bones, muscles, and joints. A specialist (often a pediatric orthopedist) will look for problems such as abnormal positioning of the feet, dislocated hips, and scoliosis -- curving of the spine.
Classifying Cerebral Palsy
Doctors classify cerebral palsy according to the type of abnormal muscle control the child experiences:
Spastic. Children with spastic cerebral palsy have increased reflexes, increased muscle tone, tight muscles, and joint contractures.
Hypotonic. These children have decreased muscle tone, resulting in weakness and joint instability.
Athetoid. Children with athetoid cerebral palsy squirm and thrash about when they become upset or excited.
Ataxic. These children generally don't have joint contractures, but they have problems with balance and tremors.
The condition is also classified by the area of the body affected. Common patterns include:
Hemiplegia (involvement of the arm and leg on one side).
Diplegia (involvement of either both legs or both feet).
Quadriplegia (involvement of all four limbs).
Doctors today can't repair the brain injury that causes cerebral palsy, but healthcare providers can use a number of tools to help control and improve symptoms.
Physical therapy to improve strength, range of motion, and joint mobility is the mainstay of treatment. Braces are often used to keep joints in appropriate positions. Medications can also reduce symptoms. Recently, physicians have begun using botulinum toxin (a purified form of a bacterium that causes food poisoning) to relax overactive muscles. Injected into the affected areas, this substance -- marketed as the drug Botox -- can sometimes temporarily restore function. Finally, surgery sometimes can help treat the problems that may develop as the child grows.
Different patients with cerebral palsy have widely differing symptoms. Treatment strategies must be tailored to the individual. In a study published in Clinics in Developmental Medicine, Dr. Eugene Bleck has shown that communication, daily activities, and general mobility are the highest priorities for these patients.
"It is important to be as honest and realistic with the patient and his or her family as possible. Once they understand the issues and the options, they are the ones who guide the treatment," explains Roye.
With input from families and an interdisciplinary team of specialists, children with cerebral palsy can improve tremendously. A cure remains elusive, but early intervention by a well-coordinated team can often make a significant difference in quality of life for affected children.