Cerebral Palsy: Causes, Treatment and Prevention
Cerebral palsy refers to a group of conditions that affect control of movement and posture. Because of damage to areas of the brain that control movement, an affected child cannot move his or her muscles normally. While symptoms range from mild to severe, the condition does not get worse as the child gets older. With treatment, most children can significantly improve their abilities.
Many children with cerebral palsy have other problems that require treatment. These include mental retardation, learning disabilities, seizures, vision, hearing and speech problems.
How common is cerebral palsy?
Cerebral palsy usually is not diagnosed until a child is about 2 to 3 years of age. Approximately 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.
What are the different types of cerebral palsy?
There are three major types of cerebral palsy, and some individuals may have symptoms of more than one type.
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 often have mental retardation and other problems.
Athetoid or Dyskinetic Cerebral Palsy
About 10 to 20 percent of affected individuals have the athetoid form of cerebral palsy, 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 can also be difficulties with sucking, swallowing and speech.
Ataxic Cerebral Palsy
About 5 to 10 percent of affected individuals have the ataxic form, which affects balance and coordination. They may walk with an unsteady gait with feet far apart, and have difficulty with motions that require precise coordination, such as writing.
What are the causes of cerebral palsy?
In about 70 percent of cases, cerebral palsy results from events occurring before birth that can disrupt normal development of the brain. Contrary to common belief, lack of oxygen reaching the fetus during labor and delivery contributes to only a small minority of cases of cerebral palsy, according to a 2003 report by the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP). A small number of babies also develop brain injuries in the first months or years of life that can result in cerebral palsy. In many cases, the cause of cerebral palsy in a child is unknown.
Some of the known causes of cerebral palsy include:
- Infections during pregnancy – Certain infections in the mother, including rubella (German measles), cytomegalovirus (a usually mild viral infection) and toxoplasmosis (a usually mild parasitic infection) can cause brain damage and result in cerebral palsy. Recent studies suggest that maternal infections involving the placental membranes (chorioamnionitis) may contribute to cerebral palsy in full-term as well as preterm babies (those born before 37 completed weeks of pregnancy). A 2003 study at the University of California at San Francisco found that full-term babies were four times more likely to develop cerebral palsy if they were exposed to chorioamnionitis in the womb. Reproductive/urinary tract infections also may increase the risk of preterm delivery, another risk factor for cerebral palsy.
- Insufficient oxygen reaching the fetus – 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. Many of these tiny babies suffer from bleeding in the brain, which can damage delicate brain tissue, or develop periventricular leukomalacia, destruction of nerves around the fluid-filled cavities (ventricles) in the brain.
- Asphyxia during labor and delivery – Until recently, it was widely believed that asphyxia (lack of oxygen) during a difficult delivery was the cause of most cases of cerebral palsy. The ACOG/AAP report shows that fewer than 10 percent of the types of brain injuries that can result in cerebral palsy are caused by asphyxia.
- Blood Diseases – Rh disease, an incompatibility between the blood of the mother and her fetus, can cause severe jaundice and brain damage, resulting in cerebral palsy. 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. Blood clotting disorders (thrombophilias) in either mother or baby also may increase the risk.
- Severe jaundice – Jaundice, yellowing of the skin and the whites of the eyes caused by the build-up of a pigment called bilirubin in the blood, occasionally becomes severe. Without treatment, severe jaundice can pose a risk of permanent brain damage resulting in athetoid cerebral palsy.
- Other birth defects – Babies with brain malformations, numerous genetic diseases and other physical birth defects are at increased risk of cerebral palsy.
- Acquired cerebral palsy– About 10 percent of children with cerebral palsy acquires 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.
How is cerebral palsy diagnosed?
Parents may become concerned about their baby’s or toddler’s development if the child is having problems learning to roll over, sit, crawl or walk. Parents always should discuss these concerns with their baby’s pediatrician.
Cerebral palsy is diagnosed mainly by evaluating how a baby or young child moves. The doctor will evaluate the child’s 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 will check the child’s reflexes and look to see if the baby has developed a preference for using his right or left hand.
While most babies do not develop a hand preference (become right- or left-handed) until at least 12 months of age, some babies with cerebral palsy do so before six months of age. Another important sign of cerebral palsy is the persistence of certain reflexes, called primitive reflexes, which are normal in younger infants, but generally disappear by 6 to 12 months of age. The doctor also will take a careful medical history, and attempt to rule out any other disorders that could be causing the symptoms.
Health care providers may also 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. Ultrasound often is recommended in preterm babies who are considered at risk of cerebral palsy to help diagnose brain abnormalities that are frequently associated with cerebral palsy (allowing therapy to begin early).
In some children with cerebral palsy, especially those who are mildly affected, brain imaging tests show no abnormalities, suggesting that microscopically small areas of brain damage can cause symptoms. About half of babies who are diagnosed with mild cerebral palsy appear to outgrow their symptoms.
How is cerebral palsy treated?
A team of health care professionals works with the child and family to identify the child’s needs and create an individualized treatment plan to help the child reach his or her maximum potential. The team is generally coordinated by one health care professional and may include pediatricians, physical medicine and rehabilitation physicians, orthopedic surgeons, physical and occupational therapists, ophthalmologists, speech/language pathologists, social workers and psychologists.
The child usually will begin physical therapy soon after diagnosis. Therapy enhances motor skills (such as sitting and walking), improves muscle strength and helps prevent contractures (shortening of muscles that limit joint movement). Sometimes braces, splints or casts are used along with physical therapy to help prevent contractures and to improve function of the hands or legs. If contractures are severe, surgery may be recommended to lengthen affected muscles.
Drugs sometimes are recommended to ease spasticity or to reduce abnormal movement. Unfortunately, oral drug treatment is often not very helpful. Sometimes injection of drugs such as Botox (botulinum toxin) directly into spastic muscles is helpful, and the effects may last several months (allowing for more effective physical therapy during that time). A new type of drug treatment is showing promise in children with moderate to severe spasticity. 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, a surgical technique called selective dorsal rhizotomy may permanently reduce spasticity and improve the ability to sit, stand and walk. In this procedure, doctors identify and cut some of the nerve fibers that are contributing most to spasticity. This procedure usually is done when a child is between 2 and 7 years of age. According to UCP, this procedure is usually recommended only for children with severe leg spasticity who have not responded well to other treatments.
Occupational therapists work with the child on skills required for daily living, including feeding and dressing. Children with speech problems work with a speech therapist or, in more severe cases, learn to use a computerized voice synthesizer that can speak for them. Computers have become an important tool for children and adults with cerebral palsy in terms of therapy, education, recreation and employment.
Some children with cerebral palsy may benefit from the many mechanical aids available today, including walkers, positioning devices (to allow a child with abnormal posture to stand correctly), customized wheelchairs, specially adapted scooters and tricycles.
Can cerebral palsy be prevented?
In many cases, the cause of cerebral palsy is not known, so there is nothing that can be done to prevent it. In spite of improvements in the care of pregnant women and sick babies, the number of babies with cerebral palsy seems to be increasing. This is due, in part, to the survival of an increasing number of very premature babies, who are at high risk of cerebral palsy.
However, some causes of cerebral palsy have been identified, and cases of cerebral palsy that result from them often can be prevented. Rh disease and congenital rubella syndrome used to be important causes of cerebral palsy. Now Rh disease usually can be prevented when an Rh-negative pregnant woman receives appropriate care. Women can be tested for immunity to rubella before pregnancy and be vaccinated if they are not immune.
Babies with severe jaundice can be treated with special lights (phototherapy). Head injuries in babies, a significant cause of cerebral palsy in the early months of life, often can be prevented when babies ride in car seats properly positioned in the back seat of the car. Routine vaccination of babies (with the Hib vaccine) prevents many cases of meningitis, another cause of brain damage in the early months. A woman can help reduce her risk of preterm delivery when she seeks early monitoring (ideally starting with a pre-pregnancy visit) and regular prenatal care and avoids cigarettes, alcohol and illicit drugs.
Where is more information available?
Additional information is available from:
United Cerebral Palsy
1660 L Street, N.W., Suite 700
Washington, DC 20036-5602
Phone: (800) 872-5827
This article was written by United Cerebral Palsy.