Cerebral palsy refers to a group of symptoms that involve difficulty moving and muscle stiffness (spasticity). It results from brain malformations that occur before birth as the brain is developing or from brain damage that occurs before, during, or shortly after birth.
Cerebral palsy affects 1 to 2 of every 1,000 infants. But it affects 15 of every 100 premature infants. It is particularly common among infants with a very low birth weight.
Cerebral palsy is not a disease. Rather, it is a group of symptoms that results from malformations in or damage to the parts of the brain that control muscle movements (motor areas). Sometimes children who have cerebral palsy also have abnormalities of other parts of the brain. Brain damage that results in cerebral palsy may occur during pregnancy, during birth, after birth, or in early childhood. Once the brain damage has occurred, it does not get worse even though the symptoms may change as the child grows and matures. If muscle malfunction results from brain damage that occurs after age 2, it is not considered cerebral palsy.
Many different types of brain malformations and brain damage can cause cerebral palsy, and sometimes more than one cause is involved. Problems that occur just before, during, and just after birth cause 15 to 20% of cases. These problems include lack of oxygen during delivery, infections, and birth injuries. During pregnancy, infections, such as rubella, toxoplasmosis, or cytomegalovirus infection, sometimes result in cerebral palsy. Sometimes the brain malformations that cause cerebral palsy result from genetic abnormalities.
Premature infants are particularly vulnerable, possibly in part because in a certain part of their brain, some of the blood vessels are thin and bleed easily. High levels of bilirubin in the blood can lead to a form of brain damage called kernicterus, which can cause cerebral palsy.
During the first years of life, severe illness, such as inflammation of the tissues covering the brain (meningitis), a severe bloodstream infection (sepsis), injury, and severe dehydration, can damage the brain and result in cerebral palsy.
Symptoms can range from clumsiness to severe spasticity that contorts the child's arms and legs, requiring mobility aids, such as braces, crutches, and wheelchairs. Because other parts of the brain may also be affected, many children with cerebral palsy have other disabilities, such as intellectual disability, behavioral problems, difficulty seeing or hearing, and seizure disorders.
There are four main types of cerebral palsy:
In all forms of cerebral palsy, speech may be hard to understand because the child has difficulty controlling the muscles involved in speech.
In the spastic type, which occurs in over 70% of children with cerebral palsy, the muscles are stiff (spastic) and weak. The stiffness may affect both arms and both legs (quadriplegia) or mainly the legs and lower part of the body (paraplegia). Often, the same parts on both sides of the body are affected (diplegia), but sometimes only the arm and leg on one side are affected (hemiplegia). The affected arms and legs are poorly developed, as well as stiff and weak. Some children may walk in a criss-cross motion, where one leg swings over the other (scissors gait), and some may walk on their toes. Crossed, lazy, or wandering eyes (strabismus) and other vision problems may occur. Children with spastic quadriplegia are the most severely affected. They commonly have intellectual disability (sometimes severe) along with seizures and trouble swallowing. Children who have trouble swallowing may choke on secretions from the mouth and stomach and inhale (aspirate) them. Aspiration inflames the lungs, causing difficulty breathing. Repeated aspiration can permanently damage the lungs. Many children with spastic hemiplegia, diplegia, or paraplegia have normal intelligence and are less likely to have seizures.
In the athetoid type, which occurs in about 20% of children with cerebral palsy, the arms, legs, and body spontaneously move slowly and involuntarily. Movements may also be writhing, abrupt, and jerky. Strong emotion makes the movements worse, and sleep makes them disappear. Children usually have normal intelligence and rarely have seizures. Difficulty articulating words clearly is common and is often severe. If the cause is kernicterus, affected children are often deaf and have difficulty looking up.
In the ataxic type, which occurs in less than 5% of children with cerebral palsy, coordination is poor, and muscles are weak. Movements become shaky when children reach for an object (a type of tremor). Children have difficulty when they try to move rapidly or do things that require fine movements. They walk unsteadily, with their legs widely spaced.
In the mixed type, two of the above types, most often spastic and athetoid, are combined. This type occurs in many children with cerebral palsy. Children with mixed types may have severe intellectual disability.
Cerebral palsy is difficult to diagnose during early infancy. As the baby matures, delays in learning to walk and developing other motor skills (motor development), spasticity, or lack of coordination become noticeable.
Although laboratory tests cannot identify cerebral palsy, a doctor may do blood tests and imaging of the brain, usually magnetic resonance imaging (MRI) to identify a cause and to look for other disorders.
If the cause is still not clear or if muscle problems seem to be getting worse or differ from those usually caused by cerebral palsy, doctors may recommend additional testing, such as electrical studies of nerves (nerve conduction) and muscles (electromyography) and genetic testing.
The specific type of cerebral palsy often cannot be distinguished before the child is 2 years old.
The prognosis usually depends on the type of cerebral palsy and on its severity. Most children with cerebral palsy survive into adulthood. Only the most severely affected—those incapable of any self-care or taking food by mouth—have a substantially shortened life expectancy. With appropriate treatment and training, many children, especially those with spastic paraplegia or hemiplegia, can lead a near-normal life.
Cerebral palsy cannot be cured, and its problems are lifelong. However, much can be done to improve a child's mobility and independence. The goal is to enable children to become as independent as they can be.
Physical therapy, occupational therapy, and braces may improve muscle control and walking, particularly when rehabilitation is started as early as possible. Speech therapy may make speech much clearer and help with swallowing problems. Constraint-induced movement therapy may help when the disorder does not affect all the limbs. For this therapy, the unaffected limb is restrained during waking hours, except during specific activities, so that children must do tasks with the affected limb. As a result, new pathways for nerve impulses may develop in the brain, enabling people to use the affected limb better.
Occupational therapists can help some children learn ways to compensate for their muscle problems and thus do daily activities (such as bathing, eating, and dressing) for themselves. Or therapists may teach children to use devices that help them do these activities.
Certain drugs may help. Injecting botulinum toxin into muscles prevents those muscles from pulling unevenly on joints and from becoming permanently shortened (called contractures). Botulinum, the bacterial toxin that causes botulism, works by paralyzing muscles. (It is the same drug that is used to treat wrinkles.) Or another drug may be injected into the nerves that stimulate the affected muscles. This drug slightly damages the nerves, lessening the muscle's pull on the joint.
Other drugs are used to lessen spasticity. They include baclofen, benzodiazepines (such as diazepam), tizanidine, and sometimes dantrolene, all taken by mouth. Some children with severe spasticity benefit from an implantable pump that provides a continuous infusion of baclofen into the fluid around the spinal cord.
Surgery may be done to cut or lengthen tendons of the stiff muscles that limit motion. Sometimes cutting certain nerve roots coming from the spinal cord (dorsal rhizotomy) reduces the spasticity and may help a few children, especially those who were born prematurely, as long as spasticity affects mainly the legs and mental function is good.
Many children with cerebral palsy grow normally and may attend regular schools if they do not have severe intellectual and physical disabilities. Other children require extensive physical therapy, need special education, and are severely limited in activities of daily living, requiring some type of lifelong care and assistance. However, even severely affected children can benefit from education and training, which increase their independence and self-esteem and greatly reduce the burden for family members or other caregivers.
Information and counseling are available to parents to help them understand their child's condition and potential and to assist with problems as they arise. Loving parental care combined with assistance from public and private agencies, such as community health agencies, health organizations such as the United Cerebral Palsy Association (UCP.org), and vocational rehabilitation organizations, can help children reach their highest potential.
Last full review/revision May 2014 by Margaret C. McBride, MD