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Cerebral Palsy FAQ
What is Cerebral
Palsy?
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)
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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
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variations in muscle tone, either too stiff or too floppy
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excessive drooling or difficulties swallowing or speaking
-
shaking (tremor) or random involuntary
movements
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difficulty with precise motions, such as writing or buttoning a
shirt.
The symptoms of cerebral palsy
differ in type and severity from one person to the next, and may even change in an individual over
time. Some people with cerebral palsy also have other medical disorders, including mental
retardation, seizures, impaired vision or hearing, and abnormal physical sensations or
perceptions.
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.
How Many People Have Cerebral
Palsy?
The United Cerebral Palsy (UCP)
Foundation estimates that nearly 800,000 children and adults in the United States are living with
one or more of the symptoms of cerebral palsy. According to the federal government’s Centers for
Disease Control and Prevention, each year about 10,000 babies born in the United States will
develop cerebral palsy.
Despite advances in preventing and
treating certain causes of cerebral palsy, the percentage of babies who develop the condition has
remained the same over the past 30 years. Improved care in neonatal intensive-care units has
resulted in higher survival rates for very low birth weight babies. Many of these infants
will have developmental defects in their nervous systems or suffer brain damage that will cause the
characteristic symptoms of cerebral palsy.
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?
There are many different causes.
Birth complications, including asphyxia, are estimated to account for up to 10 percent of the
babies born with 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 obstetrical malpractice, bacterial meningitis or viral
encephalitis, or head injury from a motor vehicle accident, a fall, or child
abuse.
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 birth weight 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 birth weight 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.
Complications During Labor and
Delivery
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:
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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.
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Complicated labor and delivery.
A baby who has vascular or respiratory problems during labor and delivery may
already have suffered brain damage or abnormalities.
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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.
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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.
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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.
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Seizures.
An infant who has seizures faces a higher risk of being diagnosed later in childhood
with cerebral palsy.
Can Cerebral Palsy Be
Prevented?
This depends on the type of
cerebral palsy. 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 of
Cerebral Palsy?
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,
hemi paresis (hemi = half) indicates that only one side of the body is
weakened. Quadriplegia (quad = four) means all four limbs are
paralyzed.
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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).
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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.
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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.
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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.
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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.
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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.
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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.
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