Cerebral Palsy
- What is Cerebral Palsy?
- What Are the Early Signs?
- What Causes Cerebral Palsy?
- What are the Risk Factors?
- Is there any treatment?
- What is the prognosis?
- What research is being done?
- Can Cerebral Palsy Be Prevented?
- What Are the Different Forms?
- What Specific Treatments Are Available?
Doctors use the term cerebral palsy to refer to any one of a number of neurological disorders that appear in infancy or early childhood and permanently affect body movement and muscle coordination but aren’t progressive, in other words, they don’t get worse over time. The term cerebral refers to the two halves or hemispheres of the brain, in this case to the motor area of the brain’s outer layer (called the cerebral cortex), the part of the brain that directs muscle movement; palsy refers to the loss or impairment of motor function.
Even though cerebral palsy affects muscle movement, it isn’t caused by problems in the muscles or nerves. It is caused by abnormalities inside the brain that disrupt the brain’s ability to control movement and posture.
In some cases of cerebral palsy, the cerebral motor cortex hasn’t developed normally during fetal growth. In others, the damage is a result of injury to the brain either before, during, or after birth. In either case, the damage is not repairable and the disabilities that result are permanent.
Children with cerebral palsy exhibit a wide variety of symptoms, including:
- lack of muscle coordination when performing voluntary movements (ataxia);
- stiff or tight muscles and exaggerated reflexes (spasticity);
- walking with one foot or leg dragging;
- walking on the toes, a crouched gait, or a “scissored” gait;
- variations in muscle tone, either too stiff or too floppy;
- excessive drooling or difficulties swallowing or speaking;
- shaking (tremor) or random involuntary movements; and
- difficulty with precise motions, such as writing or buttoning a shirt.
Cerebral palsy doesn’t always cause profound disabilities. While one child with severe cerebral palsy might be unable to walk and need extensive, lifelong care, another with mild cerebral palsy might be only slightly awkward and require no special assistance.
Cerebral palsy isn’t a disease. It isn’t contagious and it can’t be passed from one generation to the next. There is no cure for cerebral palsy, but supportive treatments, medications, and surgery can help many individuals improve their motor skills and ability to communicate with the world.
What Are the Early Signs?
The early signs of cerebral palsy usually appear before a child reaches 3 years of age. Parents are often the first to suspect that their baby’s motor skills aren’t developing normally. Infants with cerebral palsy frequently have developmental delay, in which they are slow to reach developmental milestones such as learning to roll over, sit, crawl, smile, or walk. Some infants with cerebral palsy have abnormal muscle tone as infants. Decreased muscle tone (hypotonia) can make them appear relaxed, even floppy. Increased muscle tone (hypertonia) can make them seem stiff or rigid. In some cases, an early period of hypotonia will progress to hypertonia after the first 2 to 3 months of life. Children with cerebral palsy may also have unusual posture or favor one side of the body when they move.
Parents who are concerned about their baby's development for any reason should contact their pediatrician. A doctor can determine the difference between a normal lag in development and a delay that could indicate cerebral palsy.
What Causes Cerebral Palsy?
The majority of children with cerebral palsy are born with it, although it may not be detected until months or years later. This is called congenital cerebral palsy. In the past, if doctors couldn’t identify another cause, they attributed most cases of congenital cerebral palsy to problems or complications during labor that caused asphyxia (a lack of oxygen) during birth. However, extensive research by NINDS scientists and others has shown that few babies who experience asphyxia during birth grow up to have cerebral palsy or any other neurological disorder. Birth complications, including asphyxia, are now estimated to account for only 5 to 10 percent of the babies born with congenital cerebral palsy.
A small number of children have acquired cerebral palsy, which means the disorder begins after birth. In these cases, doctors can often pinpoint a specific reason for the problem, such as brain damage in the first few months or years of life, brain infections such as bacterial meningitis or viral encephalitis, or head injury from a motor vehicle accident, a fall, or child abuse.
What causes the remaining 90 to 95 percent? Research has given us a bigger and more accurate picture of the kinds of events that can happen during early fetal development, or just before, during, or after birth, that cause the particular types of brain damage that will result in congenital cerebral palsy. There are multiple reasons why cerebral palsy happens – as the result of genetic abnormalities, maternal infections or fevers, or fetal injury, for example. But in all cases the disorder is the result of four types of brain damage that cause its characteristic symptoms:
Damage to the white matter of the brain (periventricular leukomalacia [PVL]). The white matter of the brain is responsible for transmitting signals inside the brain and to the rest of the body. PVL describes a type of damage that looks like tiny holes in the white matter of an infant’s brain. These gaps in brain tissue interfere with the normal transmission of signals. There are a number of events that can cause PVL, including maternal or fetal infection. Researchers have also identified a period of selective vulnerability in the developing fetal brain, a period of time between 26 and 34 weeks of gestation, in which periventricular white matter is particularly sensitive to insults and injury.
Abnormal development of the brain (cerebral dysgenesis). Any interruption of the normal process of brain growth during fetal development can cause brain malformations that interfere with the transmission of brain signals. The fetal brain is particularly vulnerable during the first 20 weeks of development. Mutations in the genes that control brain development during this early period can keep the brain from developing normally. Infections, fevers, trauma, or other conditions that cause unhealthy conditions in the womb also put an unborn baby’s nervous system at risk.
Bleeding in the brain (intracranial hemorrhage). Intracranial hemorrhage describes bleeding inside the brain caused by blocked or broken blood vessels. A common cause of this kind of damage is fetal stroke. Some babies suffer a stroke while still in the womb because of blood clots in the placenta that block blood flow. Other types of fetal stroke are caused by malformed or weak blood vessels in the brain or by blood-clotting abnormalities. Maternal high blood pressure (hypertension) is a common medical disorder during pregnancy that has been known to cause fetal stroke. Maternal infection, especially pelvic inflammatory disease, has also been shown to increase the risk of fetal stroke.
Brain damage caused by a lack of oxygen in the brain (hypoxic-ischemic encephalopathy or intrapartum asphyxia). Asphyxia, a lack of oxygen in the brain caused by an interruption in breathing or poor oxygen supply, is common in babies due to the stress of labor and delivery. But even though a newborn’s blood is equipped to compensate for short-term low levels of oxygen, if the supply of oxygen is cut off or reduced for lengthy periods, an infant can develop a type of brain damage called hypoxic-ischemic encephalopathy, which destroys tissue in the cerebral motor cortex and other areas of the brain. This kind of damage can also be caused by severe maternal low blood pressure, rupture of the uterus, detachment of the placenta, or problems involving the umbilical cord.
What are the Risk Factors?
Just as there are particular types of brain damage that cause cerebral palsy, there are also certain medical conditions or events that can happen during pregnancy and delivery that will increase a baby’s risk of being born with cerebral palsy. Research scientists have examined thousands of expectant mothers, followed them through childbirth, and monitored their children’s early neurological development to establish these risk factors. If a mother or her baby has any of these risk factors, it doesn’t mean that cerebral palsy is inevitable, but it does increase the chance for the kinds of brain damage that cause it.
Low birthweight and premature birth. The risk of cerebral palsy is higher among babies who weigh less than 5 ½ pounds at birth or are born less than 37 weeks into pregnancy. The risk increases as birthweight falls or weeks of gestation shorten. Intensive care for premature infants has improved dramatically over the course of the past 30 years. Babies born extremely early are surviving, but with medical problems that can put them at risk for cerebral palsy. Although normal- or heavier-weight babies are at relatively low individual risk for cerebral palsy, term or near-term babies still make up half of the infants born with the condition.
Multiple births. Twins, triplets, and other multiple births -- even those born at term -- are linked to an increased risk of cerebral palsy. The death of a baby’s twin or triplet further increases the risk.
Infections during pregnancy. Infectious diseases caused by viruses, such as toxoplasmosis, rubella (German measles), cytomegalovirus, and herpes, can infect the womb and placenta. Researchers currently think that maternal infection leads to elevated levels of immune system cells called cytokines that circulate in the brain and blood of the fetus. Cytokines respond to infection by triggering inflammation. Inflammation may then go on to cause central nervous system damage in an unborn baby. Maternal fever during pregnancy or delivery can also set off this kind of inflammatory response.
Blood type incompatibility. Rh incompatibility is a condition that develops when a mother’s Rh blood type (either positive or negative) is different from the blood type of her baby. Because blood cells from the baby and mother mix during pregnancy, if a mother is negative and her baby positive, for example, the mother’s system won’t tolerate the presence of Rh-positive red blood cells. Her body will begin to make antibodies that will attack and kill her baby’s blood cells. Rh incompatibility is routinely tested for and treated in the United States , but conditions in other countries continue to keep blood type incompatibility a risk factor for cerebral palsy.
Exposure to toxic substances. Mothers who have been exposed to toxic substances during pregnancy, such as methyl mercury, are at a heightened risk of having a baby with cerebral palsy.
Mothers with thyroid abnormalities, mental retardation, or seizures. Mothers with any of these conditions are slightly more likely to have a child with cerebral palsy.
There are also medical conditions during labor and delivery, and immediately after delivery, that act as warning signs for an increased risk of cerebral palsy. Knowing these warning signs helps doctors keep a close eye on children who face a higher risk. However, parents shouldn’t become too alarmed if their baby has one or more of these conditions at birth. Most of these children will not develop cerebral palsy. Warning signs include:
Breech presentation. Babies with cerebral palsy are more likely to be in a breech position (feet first) instead of head first at the beginning of labor.
Complicated labor and delivery. A baby who has vascular or respiratory problems during labor and delivery may already have suffered brain damage or abnormalities.
Small for gestational age. Babies born smaller than normal for their gestational age are at risk for cerebral palsy because of factors that kept them from growing naturally in the womb.
Low Apgar score. The Apgar score is a numbered rating that reflects a newborn's condition. To determine an Apgar score, doctors periodically check a baby's heart rate, breathing, muscle tone, reflexes, and skin color during the first minutes after birth. They then assign points; the higher the score, the more normal a baby's condition. A low score at 10-20 minutes after delivery is often considered an important sign of potential problems such as cerebral palsy.
Jaundice. More than 50 percent of newborns develop jaundice after birth when bilirubin, a substance normally found in bile, builds up faster than their livers can break it down and pass it from the body. Severe, untreated jaundice can cause a neurological condition known as kernicterus, which kills brain cells and can cause deafness and cerebral palsy.
Seizures. An infant who has seizures faces a higher risk of being diagnosed later in childhood with cerebral palsy.
Is there any treatment?
Cerebral palsy can’t be cured, but treatment will often improve a child's capabilities. Many children go on to enjoy near-normal adult lives if their disabilities are properly managed. In general, the earlier treatment begins the better chance children have of overcoming developmental disabilities or learning new ways to accomplish the tasks that challenge them. Treatment may include physical and occupational therapy, speech therapy, drugs to control seizures, relax muscle spasms, and alleviate pain; surgery to correct anatomical abnormalities or release tight muscles; braces and other orthotic devices; wheelchairs and rolling walkers; and communication aids such as computers with attached voice synthesizers.
What is the prognosis?
Cerebral palsy doesn’t always cause profound disabilities. While one child with severe cerebral palsy might be unable to walk and need extensive, lifelong care, another with mild cerebral palsy might be only slightly awkward and require no special assistance. Supportive treatments, medications, and surgery can help many individuals improve their motor skills and ability to communicate with the world.
What research is being done?
Researchers are investigating the roles of mishaps early in brain development, including genetic defects, which are sometimes responsible for the brain malformations and abnormalities that result in cerebral palsy. Scientists are also looking at traumatic events in newborn babies’ brains, such as bleeding, epileptic seizures, and breathing and circulation problems, which can cause the abnormal release of chemicals that trigger the kind of damage that causes cerebral palsy. To make sure children are getting the right kinds of therapies, studies are also being done that evaluate both experimental treatments and treatments already in use so that physicians and parents have valid information to help them choose the best therapy.
Can Cerebral Palsy Be Prevented?
Cerebral palsy related to genetic abnormalities is not preventable, but a few of the risk factors for congenital cerebral palsy can be managed or avoided. For example, rubella, or German measles, is preventable if women are vaccinated against the disease before becoming pregnant. Rh incompatibilities can also be managed early in pregnancy. But there are still risk factors that can’t be controlled or avoided in spite of medical intervention.
For example, the use of electronic fetal monitoring machines to keep track of an unborn baby’s heartbeat during labor, and the use of emergency cesarean section surgery when there are significant signs of fetal distress, haven’t lowered the numbers of babies born with cerebral palsy. Interventions to treat other prenatal causes of cerebral palsy, such as therapies to prevent prenatal stroke or antibiotics to cure intrauterine infections, are either difficult to administer or haven’t yet been proven to lower the risk of cerebral palsy in vulnerable infants.
Fortunately, acquired cerebral palsy, often due to head injury, is preventable using common safety tactics, such as using car seats for infants and toddlers, and making sure young children wear helmets when they ride bicycles. In addition, common sense measures around the household, such as supervising babies and young children closely when they bathe, can reduce the risk of accidental injury.
Despite the best efforts of parents and physicians, however, children will still be born with cerebral palsy. Since in many cases the cause or causes of cerebral palsy aren’t fully known, little can currently be done to prevent it. As investigators learn more about the causes of cerebral palsy through basic and clinical research, doctors and parents will know more about how to prevent this disorder.
What Are the Different Forms?
The specific forms of cerebral palsy are determined by the extent, type, and location of a child’s abnormalities. Doctors classify cerebral palsy according to the type of movement disorder involved -- spastic (stiff muscles), athetoid (writhing movements), or ataxic (poor balance and coordination) -- plus any additional symptoms. Doctors will often describe the type of cerebral palsy a child has based on which limbs are affected. The names of the most common forms of cerebral palsy use Latin terms to describe the location or number of affected limbs, combined with the words for weakened (paresis) or paralyzed (plegia). For example, hemiparesis (hemi = half) indicates that only one side of the body is weakened. Quadriplegia (quad = four) means all four limbs are paralyzed.
Spastic hemiplegia/hemiparesis. This type of cerebral palsy typically affects the arm and hand on one side of the body, but it can also include the leg. Children with spastic hemiplegia generally walk later and on tip-toe because of tight heel tendons. The arm and leg of the affected side are frequently shorter and thinner. Some children will develop an abnormal curvature of the spine (scoliosis). Depending on the location of the brain damage, a child with spastic hemiplegia may also have seizures. Speech will be delayed and, at best, may be competent, but intelligence is usually normal.
Spastic diplegia/diparesis. In this type of cerebral palsy, muscle stiffness is predominantly in the legs and less severely affects the arms and face, although the hands may be clumsy. Tendon reflexes are hyperactive. Toes point up. Tightness in certain leg muscles makes the legs move like the arms of a scissor. Children with this kind of cerebral palsy may require a walker or leg braces. Intelligence and language skills are usually normal.
Spastic quadriplegia/quadriparesis. This is the most severe form of cerebral palsy, often associated with moderate-to-severe mental retardation. It is caused by widespread damage to the brain or significant brain malformations. Children will often have severe stiffness in their limbs but a floppy neck. They are rarely able to walk. Speaking and being understood are difficult. Seizures can be frequent and hard to control.
Dyskinetic cerebral palsy (also includes athetoid, choreoathetoid, and dystonic cerebral palsies). This type of cerebral palsy is characterized by slow and uncontrollable writhing movements of the hands, feet, arms, or legs. In some children, hyperactivity in the muscles of the face and tongue makes them grimace or drool. They find it difficult to sit straight or walk. Children may also have problems coordinating the muscle movements required for speaking. Intelligence is rarely affected in these forms of cerebral palsy.
Ataxic cerebral palsy. This rare type of cerebral palsy affects balance and depth perception. Children will often have poor coordination and walk unsteadily with a wide-based gait, placing their feet unusually far apart. They have difficulty with quick or precise movements, such as writing or buttoning a shirt. They may also have intention tremor, in which a voluntary movement, such as reaching for a book, is accompanied by trembling that gets worse the closer their hand gets to the object.
Mixed types. It is common for children to have symptoms that don’t correspond to any single type of cerebral palsy. Their symptoms are a mix of types. For example, a child with mixed cerebral palsy may have some muscles that are too tight and others that are too relaxed, creating a mix of stiffness and floppiness.
What Specific Treatments Are Available?
Physical therapy, usually begun in the first few years of life or soon after the diagnosis is made, is a cornerstone of cerebral palsy treatment. Physical therapy programs use specific sets of exercises and activities to work toward two important goals: preventing weakening or deterioration in the muscles that aren’t being used (disuse atrophy), and keeping muscles from becoming fixed in a rigid, abnormal position (contracture).
Resistive exercise programs (also called strength training) and other types of exercise are often used to increase muscle performance, especially in children and adolescents with mild cerebral palsy. Daily bouts of exercise keep muscles that aren’t normally used moving and active and less prone to wasting away. Exercise also reduces the risk of contracture, one of the most common and serious complications of cerebral palsy.
Normally growing children stretch their muscles and tendons as they run, walk, and move through their daily activities. This insures that their muscles grow at the same rate as their bones. But in children with cerebral palsy, spasticity prevents muscles from stretching. As a result, their muscles don’t grow fast enough to keep up with their lengthening bones. The muscle contracture that results can set back the gains in function they’ve made. Physical therapy alone or in combination with special braces (called orthotic devices) helps prevent contracture by stretching spastic muscles.
Occupational therapy. This kind of therapy focuses on optimizing upper body function, improving posture, and making the most of a child’s mobility. An occupational therapist helps a child master the basic activities of daily living, such as eating, dressing, and using the bathroom alone. Fostering this kind of independence boosts self-reliance and self-esteem, and also helps reduce demands on parents and caregivers.
Recreational therapies. Recreational therapies, such as therapeutic horseback riding (also called hippotherapy), are sometimes used with mildly impaired children to improve gross motor skills. Parents of children who participate in recreational therapies usually notice an improvement in their child’s speech, self-esteem, and emotional well-being.
Controversial physical therapies. "Patterning" is a physical therapy based on the principle that children with cerebral palsy should be taught motor skills in the same sequence in which they develop in normal children. In this controversial approach, the therapist begins by teaching a child elementary movements such as crawling -- regardless of age – before moving on to walking skills. Some experts and organizations, including the American Academy of Pediatrics, have expressed strong reservations about the patterning approach because studies have not documented its value.
Experts have similar reservations about the Bobath technique (which is also called “neurodevelopmental treatment”), named for a husband and wife team who pioneered the approach in England . In this form of physical therapy, instructors inhibit abnormal patterns of movement and encourage more normal movements.
The Bobath technique has had a widespread influence on the core physical therapies of cerebral palsy treatment, but there is no evidence that the technique improves motor control. The American Academy of Cerebral Palsy and Developmental Medicine reviewed studies that measured the impact of neurodevelopmental treatment and concluded that there was no strong evidence supporting its effectiveness for children with cerebral palsy.
Conductive education, developed in Hungary in the 1940s, is another physical therapy that at one time appeared to hold promise. Conductive education instructors attempt to improve a child’s motor abilities by combining rhythmic activities, such as singing and clapping, with physical maneuvers on special equipment. The therapy, however, has not been able to produce consistent or significant improvements in study groups.
Speech and language therapy. About 20 percent of children with cerebral palsy are unable to produce intelligible speech. They also experience challenges in other areas of communication, such as hand gestures and facial expressions, and they have difficulty participating in the basic give and take of a normal conversation. These challenges will last throughout their lives.
Speech and language therapists (also known as speech therapists or speech-language pathologists) observe, diagnose, and treat the communication disorders associated with cerebral palsy. They use a program of exercises to teach children how to overcome specific communication difficulties.
For example, if a child has difficulty saying words that begin with "b," the therapist may suggest daily practice with a list of "b" words, increasing their difficulty as each list is mastered. Other kinds of exercises help children master the social skills involved in communicating by teaching them to keep their head up, maintain eye contact, and repeat themselves when they are misunderstood.
Speech therapists can also help children with severe disabilities learn how to use special communication devices, such as a computer with a voice synthesizer, or a special board covered with symbols of everyday objects and activities to which a child can point to indicate his or her wishes.
Speech interventions often use a child’s family members and friends to reinforce the lessons learned in a therapeutic setting. This kind of indirect therapy encourages people who are in close daily contact with a child to create opportunities for him or her to use their new skills in conversation.
Treatments for problems with eating and drooling are often necessary when children with cerebral palsy have difficulty eating and drinking because they have little control over the muscles that move their mouth, jaw, and tongue. They are also at risk for breathing food or fluid into the lungs. Some children develop gastroesophageal reflux disease (GERD, commonly called heartburn) in which a weak diaphragm can’t keep stomach acids from spilling into the esophagus. The irritation of the acid can cause bleeding and pain.
Individuals with cerebral palsy are also at risk for malnutrition, recurrent lung infections, and progressive lung disease. The individuals most at risk for these problems are those with spastic quadriplegia.
Initially, children should be evaluated for their swallowing ability, which is usually done with a modified barium swallow study. Recommendations regarding diet modifications will be derived from the results of this study.
In severe cases where swallowing problems are causing malnutrition, a doctor may recommend tube feeding, in which a tube delivers food and nutrients down the throat and into the stomach, or gastrostomy, in which a surgical opening allows a tube to be placed directly into the stomach.
Although numerous treatments for drooling have been tested over the years, there is no one treatment that helps reliably. Anticholinergic drugs – such as glycopyrolate -- can reduce the flow of saliva but may cause unpleasant side effects, such as dry mouth, constipation, and urinary retention. Surgery, while sometimes effective, carries the risk of complications. Some children benefit from biofeedback techniques that help them recognize more quickly when their mouths fall open and they begin to drool. Intraoral devices (devices that fit into the mouth) that encourage better tongue positioning and swallowing are still being evaluated, but appear to reduce drooling for some children.
Information Obtained From National Institute Of Health