Unknown: Cerebral Palsy
Unknown: Cerebral Palsy
Cerebral palsy (CP) is the name of a group of disorders of the central nervous system that affect a person's ability to control body movement and coordination. These disorders typically appear in infancy or early childhood. They are not contagious and are not progressive; that is, they do not get worse over time even though the disabilities are permanent.
CP refers to various injuries to the brain that can occur during pregnancy or at any point during a child's first three years of life. The severity of symptoms varies considerably; some children are only mildly affected while others are almost completely disabled. Although problems with movement and coordination are the defining characteristics of cerebral palsy, 30–50 percent of patients diagnosed with CP are also mentally retarded, and 15–60 percent have epilepsy. Other patients have problems with vision and hearing.
Doctors distinguish four basic types of cerebral palsy according to the nature of the movement disorder involved.
- Spastic: The most common type of CP, spastic cerebral palsy is characterized by stiffness of the muscles. These children may also have scoliosis (an abnormal curvature of the spine) and possibly seizures. About 81 percent of children diagnosed with CP have the spastic form. It may affect only one side of the body, affect both legs, or affect all four limbs.
- Athetoid (also called dyskinetic): The child's movements have a twisting, jerky, or writhing quality. Children with athetoid CP may drool or make strange faces if the facial muscles are affected by the disorder. About 20 percent of children with CP have the athetoid type.
- Ataxic: The child with ataxic CP has difficulty walking because of poor balance, poor depth perception, and loss of coordination. This is the least common type of CP.
- Mixed: The child has a mixture of symptoms that do not correspond neatly to any of the three previous types.
According to the Centers for Disease Control and Prevention (CDC), about twenty-three children in every 10,000 in the United States have cerebral palsy. Each year about 10,000 children are born in the United States with symptoms of CP. The United Cerebral Palsy Foundation estimates that nearly 800,000 children and adults in the United States are living with one or more of the symptoms of the disorder.
Cerebral palsy affects children of all races and ethnic groups; however, boys appear to be at slightly higher risk than girls. There are about 135 boys with cerebral palsy for every 100 girls with the disorder.
Since the 1960s, doctors have identified a number of risk factors for cerebral palsy:
- Premature birth
- Very low birth weight
- Complicated and lengthy childbirth
- Infection in the mother during pregnancy, most often genital herpes, rubella, or toxoplasmosis
- Head injury
- Multiple births (twins or triplets)
- High blood pressure, seizures, mental retardation, or thyroid disorders in the mother
- Exposure to certain toxic chemicals
- Jaundice in the baby
At one time it was thought that cerebral palsy was caused by difficulties in childbirth that cut off the flow of oxygen to the baby's brain long enough to cause brain damage. However, birth complications are now thought to account for only 5–10 percent of cases of CP. It now appears that most cases of CP begin before the baby's birth and are the end result of a number of different factors ranging from genetic mutations to infections and trauma.
Doctors have identified four different types of brain injury that may give rise to CP:
- Damage to the white matter of the brain. This is the part of the brain that transmits nerve signals to other parts of the brain and to the rest of the body. It can be damaged before birth by infections in the mother.
- Abnormal development of the various structures in the brain. This type of brain damage is sometimes caused by genetic mutations that affect the development of the central nervous system. It can also occur before birth as a result of fever, infection, or trauma to the mother.
- Bleeding in the brain. A baby can develop bleeding inside the brain or even a stroke before birth if the mother has high blood pressure.
- Damage caused by loss of oxygen to brain tissue. The parts of the baby's brain that control movement and coordination can be damaged by a long period of oxygen deprivation. This can happen if the mother has low blood pressure or if problems with blood flow to the baby occur.
Cerebral palsy is not always obvious at the time of a child's birth. In many cases, the parents first notice developmental delays; that is, the child does not sit, stand, or walk at the normal times for these milestones. In other cases, the child's muscle tone is not normal; his or her limbs may seem either loose and floppy or stiff and rigid. A common pattern is an early period of low muscle tone and floppy limbs followed by a phase of muscular rigidity and tightness. Other early symptoms of CP may include scissors movements of the legs or other abnormal movements, or reflexes that persist long after they disappear in normally developing children.
Other symptoms of CP may include:
- Difficulty nursing or feeding.
- Irregular breathing patterns.
- Mental retardation.
- Problems with speech, sight, or hearing.
- Peg-shaped rather than normally shaped teeth, and a high rate of dental cavities.
- Limited range of motion in the joints.
- Difficulties with bowel and bladder control.
- Deformities of the arms or legs. Children who are affected by CP on only one side of the body often have smaller or shorter limbs on the affected side.
There is no single laboratory or imaging test that can be used to diagnose cerebral palsy. The diagnosis is based on a thorough physical examination of the child and a detailed history of the mother's pregnancy and
childbirth. The baby's parents will be asked for a complete medical history of both the mother's and father's families; the mother's medical problems or infections (if any) before and during pregnancy; and a detailed account of the pregnancy, labor, and delivery. The parents will also be asked to describe the baby's early mental and physical development.
Although CP is often present at birth, it is difficult to evaluate during the first six to nine months of the child's life. Most children with cerebral palsy are diagnosed between one and two years of age.
The doctor may order various tests and imaging studies in order to rule out other possible causes of the baby's symptoms.
- Blood and urine tests. These may be done to rule out disorders caused by hormone imbalances or metabolic disturbances.
- Genetic testing. This type of testing may be done to rule out genetic disorders that are associated with delayed development.
- Imaging studies. Computed tomography (CT) scans and magnetic resonance imaging (MRI) are the techniques most commonly used to evaluate a child with CP.
- Electroencephalogram (EEG). An EEG is a record of the child's brain waves made by a machine attached to electrodes placed at various locations on the child's skull. It may be used to evaluate seizures in children with CP.
There is no cure for cerebral palsy. Treatments for children with CP are individualized because the symptoms vary so much from one child to another; they also often change over time as a child grows older. The various types of treatments and therapies that a child with cerebral palsy may need include:
- Rehabilitation and physical therapy. Children with the spastic form of CP may be treated with splints, braces, casts, walkers, and other devices as well as exercise therapy in order to improve the range of motion in their joints.
- Occupational therapy. This form of treatment helps the child to learn skills that he or she will need for self-care, such as feeding, dressing, and grooming.
- Speech and language therapy. This type of therapy is needed for children with hearing problems related to CP as well as those whose throat and facial muscles are affected by the disorder.
- Medications. These are often prescribed to treat seizures, digestive disorders, and muscle cramps or spasms.
- Nutritional therapy. Children with CP often have difficulties with swallowing food or eating balanced diets. A dietitian may be consulted for advice about special diets or tube feeding.
- Vision and hearing aids.
- Surgery. Some children with cerebral palsy develop severe deformities of the spine or contractures of the muscles that require surgical correction.
- Special education programs. Children with CP range from those with normal intelligence who can often participate in mainstream school programs to those with severe mental retardation. In many cases personal computers can be used by children with CP to improve their communication skills as well as complete homework assignments and keep up with schoolwork.
The prognosis for people with cerebral palsy depends in part on the severity of their symptoms and the parts of the body that are affected by the brain damage. Those with mild symptoms have a normal life expectancy; however, those with severe problems have a shortened life span. It is estimated that about 25 percent of children with CP have very few limitations on their activities; they can complete school and eventually live independently. Another 50 percent can learn to walk, feed, and clothe themselves, and take care of their body functions but cannot live without some form of part-time help from others. Only 25 percent are so severely disabled that they require extensive care and cannot learn to walk.
Many cases of cerebral palsy cannot be prevented. A pregnant woman can, however, lower her risk of having a child with the disorder by quitting smoking, drinking alcohol, and using drugs during pregnancy—all of these increase the risk of giving birth prematurely. She should also
be tested for immunity to rubella before becoming pregnant and get immunized against the disease if she is not already immune.
The number of people in the United States affected by cerebral palsy has increased since the 1960s. This increase may be due to the fact that larger numbers of premature infants are surviving. Many of these infants will have nervous system defects or suffer brain damage that causes the characteristic symptoms of cerebral palsy. Research is concentrated on ways to detect damage to a baby's brain before birth. Researchers hope that information provided by new approaches to early diagnosis may eventually lead to new treatments for the disorder.
SEE ALSO Developmental disability; Genital herpes; Rubella; Scoliosis; Toxoplasmosis
WORDS TO KNOW
Contracture: A permanent shortening of muscle tissue resulting in deformity or loss of function in a limb or joint.
Jaundice: A yellowish discoloration of the skin and whites of the eyes caused by increased levels of bile pigments from the liver in the patient's blood.
Scoliosis: Abnormal curvature of the spine from side to side.
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Mayo Clinic. Cerebral Palsy. Available online at http://www.mayoclinic.com/health/cerebral-palsy/DS00302 (updated November 14, 2006; accessed June 9, 2008).
National Institute of Neurological Disorders and Stroke (NINDS). Cerebral Palsy: Hope through Research. Available online at http://www.ninds.nih.gov/disorders/cerebral_palsy/detail_cerebral_palsy.htm (updated February 7, 2008; accessed June 9, 2008).
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