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archerey
2001-05-28 01:21:52 (UTC)

Gale Encyclopedia of Medicine..

Gale Encyclopedia of Medicine

Cerebral palsy

Author/s: Richard Robinson

Definition
Cerebral palsy (CP), or static encephalopathy, is the name
for a collection of movement disorders caused by brain
damage that occurs before, during, or shortly after birth.
A person with CP is often also affected by other conditions
caused by brain damage.

Description
The affected muscles of a person with CP may become rigid
or excessively loose, or the person may lose control of
muscles, or have problems with balance and coordination. A
combination of these is also possible. The person may be
primarily affected in the legs (paraplegia or diplegia), or
in the arm and leg of one side of the body (hemiplegia), or
all four limbs may be involved (quadriplegia).

A person with CP may also be affected by a number of other
problems, including seizure disorder, visual deficits,
hearing problems, mental retardation, learning
disabilities, and attention-deficit/hyperactivity disorder.
None of these is necessarily part of CP, however, and a
person with CP may have no other impairments except for the
movement disorder.

CP affects approximately 500,000 children and adults in the
United States, and is diagnosed in more than 6,000 newborns
and young children each year. CP is not an inherited
disorder, and as of yet there is no way to predict with
certainty which children will develop it. It is not a
disease, and is not communicable. CP is a nonprogressive
disorder, which means that symptoms neither worsen nor
improve over time. However manifestation of the symptoms
may become more severe over time; for example, rigidity of
muscles can lead to contractures and deformities that
require a variety of interventions.

Causes & symptoms
Causes
Cerebral palsy is caused by damage to the motor control
centers of the brain. When the nerve cells (neurons) in
these regions die, the appropriate signals can no longer be
sent to the muscles under their control. The resulting poor
control of these muscles causes the symptoms of CP.

This brain damage may be caused by lack of oxygen
(asphyxia), infection, trauma, malnutrition, drugs or other
chemicals, or hemorrhage. In most cases it is impossible to
determine the actual cause, although prematurity is
recognized as a significant risk factor. Although it was
once thought that difficult or prolonged delivery was
responsible for many cases of CP, most researchers now
believe that the great majority of cases result from brain
damage occurring before birth. The same injury that damages
the motor areas can harm other areas as well, leading to
other problems commonly associated with CP.

If brain cells do not get enough oxygen because of poor
circulation, they may die. Defects in circulation in the
developing brain may cause CP in some cases. Asphyxia
during birth is also possible, and about half of newborns
known to have suffered asphyxia during birth (perinatal
asphyxia) develop CP. However, asphyxia during birth is
usually considered a symptom of an underlying neurological
problem in a newborn, rather than its cause, and the
resulting CP may be another sign of that problem. Asphyxia
after birth can be caused by choking, poisoning (such as
from carbon monoxide or barbiturates), or near-drowning.


The fetal brain may be damaged by an infection contracted
by the mother. Infections correlated with CP include
rubella (German measles), toxoplasmosis (often contracted
from cat feces or undercooked meat), cytomegalovirus (a
herpes virus), and HIV (the virus that causes AIDS).
Encephalitis and meningitis, infections of the brain and
its coverings, can also cause CP when contracted by infants.

Physical trauma to the pregnant mother or infant may cause
brain damage. Blows to the infant's head, as from a motor
vehicle accident, violent shaking, or other physical abuse
can damage the infant's brain. Maternal malnutrition may
cause brain damage, as can the use of drugs, including
cocaine or alcohol. Although these factors may cause CP,
they may be more likely to cause mental retardation or
other impairments.

Incompatibility between the Rh blood types of mother and
child was once a major cause of athetoid CP, one type of
movement impairment seen in cerebral palsy. In some cases,
this incompatibility can cause the mother's defense
(immune) system to attack and destroy the child's blood
cells during the pregnancy, a condition called
erythroblastosis fetalis. High levels in the child's
circulation of a blood cell breakdown product called
bilirubin can result, leading to yellowish pigmentation of
the skin caused by bile (jaundice) and causing brain
damage. This condition is now rare because of testing
procedures that identify potential Rh incompatibility, and
treatment procedures that prevent the mother's immune
system from attacking the child's blood cells. Jaundice
that does occur can be treated with special lights that
help the breakdown of bilirubin. Blood transfusions for the
child are also possible in extreme cases. Despite the
virtual elimination of this cause of CP in the last few
decades, CP rates have not declined, largely because of the
increase of survival of premature babies.

Prematurity is one of the most significant risk factors for
CP. About 7% of babies weighing less than 3 lbs at birth
develop CP, and the risk increases dramatically as weight
falls. Prematurity may increase the risk of CP because of
the increased likelihood of hemorrhaging in the brain
associated with low birth weight. Brain hemorrhage is most
common in babies born weighing less that 4 lbs, and the
risk increases as weight decreases. The hemorrhage may
destroy brain tissue, either through asphyxia or release of
toxic breakdown products.

Symptoms
The symptoms of CP are usually not noticeable at birth; as
children develop through the first 18 months of life,
though, they progress through a predictable set of
developmental milestones. Children with CP will develop
these skills more slowly because of their motor
impairments, and delay in reaching milestones is usually
the first symptom of CP. The more severe the CP, the
earlier the diagnosis is usually made.

Selected developmental milestones, and the ages at which a
child will normally acquire them, are given below. There is
some cause for concern if the child does not acquire the
skill by the age shown in parentheses.

Sits well unsupported--6 months (8-10 months)
Babbles--6 months (8 months)
Crawls--9 months (12 months)
Finger feeds, holds bottle--9 months (12 months)
Walks alone--12 months (15-18 months)
Uses one or two words other than dada/mama--12 months (15
months)
Walks up and down steps--24 months (24-36 months)
Turns pages in books; removes shoes and socks--24 months
(30 months).


Children do not consistently favor one hand over the other
before 18 months, and doing so may be a sign that the child
has difficulty using the other hand. This same preference
for one side of the body may show up as an asymmetric
crawling effort, or continuing to use only one leg for the
work of stair climbing after age three.

It must be remembered that children normally progress at
somewhat different rates, and slow beginning accomplishment
is often followed by normal development. There are also
other causes for delay in reaching some milestones,
including problems with vision or hearing. Because CP is a
nonprogressive disease, loss of previously acquired
milestones indicates that CP is not the cause of the
problem.

The impairments of CP become recognizable in early
childhood. The type of motor impairment and its location
are used as the basis for classification. There are five
generally recognized types of impairment:

Spastic--Muscles are rigid, posture may be abnormal, and
fine motor control is impaired
Athetoid--Marked by slow, writhing, involuntary movements
Hypotonic--Muscles are floppy, without tone
Ataxic--Balance and coordination are impaired
Dystonic--Mixed.
The location of the impairment usually falls into one of
three broad categories:

Hemiplegia--One arm and one leg on the same side of the
body involved
Diplegia--Both legs; arms may be partially involved
Quadriplegia--All four extremities involved.
Therefore, a person with CP may be said to have spastic
diplegia, or ataxic hemiplegia, for instance. CP is also
termed mild, moderate, or severe, although these are
subjective categories with no firm boundaries.

Loss of muscle control, especially of the spastic type, can
cause serious orthopedic problems, including scoliosis
(spine curvature), hip dislocation, or contractures. A
contracture is a shortening of a muscle, caused by an
imbalance of opposing force from a neighboring muscle.
Contractures begin as prolonged contractions, but can
become fixed or irreversible without regular range of
motion exercises. A fixed contracture occurs when the
contracted muscle adapts by reducing its overall length.
Fixed contractures may cause postural abnormalities in the
affected limbs, including clenched fists, tightly pressed
or crossed thighs, or equinus. In equinus, the most common
postural deformity, the foot is extended by the strong pull
of the rear calf muscles, causing the toes to point. The
foot is commonly pulled inward as well, a condition called
equinovarus. Contractures of all kinds may be painful, and
may interfere with normal activities of daily living,
including hygiene and mobility.

As noted, the brain damage that causes CP may also cause a
large number of other disorders. These may include:

Mental retardation
Learning disabilities
Attention-deficit/hyperactivity disorder
Seizure disorder
Visual impairment, especially strabismus ("cross-eye")
Hearing loss
Speech impairment.


These problems may have an even greater impact on the
child's life than the physical impairment of CP, although
not all children with CP are affected by other problems.
About one-third of children with CP have moderate-to-severe
mental retardation, one-third have mild mental retardation,
and one-third have normal to above average intelligence.

Diagnosis
The tracking of developmental progress is the most
important test the physician has in determining whether a
child has cerebral palsy. Most children with CP can be
confidently diagnosed by 18 months. However, diagnosing CP
is not always easy, since variations in child development
may account for delays in achieving milestones, and since
even children who are obviously delayed may continue to
progress through the various developmental stages, and
attain a normal range of skills later on. Serious or
prolonged childhood illness may cause delays that are made
up later on.

Evidence of other risk factors may aid the diagnosis. The
Apgar score, evaluated immediately after birth, measures
the newborn's heart rate, cry, color, muscle tone, and
motor reactions. Apgar scores of less than 3 out a possible
10 are associated with a highly increased risk for CP.
Presence of abnormal muscle tone or movements may signal
CP, as may the persistence of infantile reflexes. A child
with seizures or congenital organ malformation has an
increased likelihood of CP. Ultrasound examination, a
diagnostic technique that creates a two-dimensional image
of internal body structures, may help to identify brain
abnormalities, such as enlarged ventricles (chambers
containing fluid) or periventricular leukomalacia (an
abnormality of the area surrounding the ventricles), which
may be associated with CP.

X rays, MRIs, and CT scans are often used to look for
scarring, cysts, expansion of the cerebral ventricles
(hydrocephalus), or other brain abnormalities that may
indicate the cause of the symptoms. Blood tests and genetic
tests may be used to rule out other possible causes,
including muscular dystrophy (a disease characterized by
the progressive wasting of muscles), mitochondrial
(cellular) disease, other inherited disorders, or infection.

Treatment
Cerebral palsy cannot be cured, but many of the
disabilities it causes can be managed through planning and
timely care. Treatment for a child with CP depends on the
severity, nature, and location of the impairment, as well
as the associated problems the child has. Optimal care of a
child with mild CP may involve regular interaction with
only a physical therapist and occupational therapist,
whereas care for a more severely affected child may include
a speech-language therapist, special education teacher,
adaptive sports therapist, nutritionist, orthopedic
surgeon, and neurosurgeon. Since CP is not a progressive
disorder, its symptoms will not worsen with time.
Nonetheless, the way in which those symptoms affect the
growing child will change over time, and may require new
strategies for treatment, adaptation, and compensation.


Parents of a child newly diagnosed with CP are not likely
to have the necessary expertise to coordinate the full
range of care their child will need. Although knowledgeable
and caring medical professionals are indispensable for
developing a care plan, a potentially more important source
of information and advice is other parents who have dealt
with the same set of difficulties. Support groups of
parents of physically or mentally impaired children can be
significant sources of both practical advice and emotional
support. Many cities have support groups that can be
located through the United Cerebral Palsy Association or a
local hospital or social service agency. Children with CP
are also eligible for special education services. The
diagnosing doctor should refer parents to the local school
district for these services. Even children aged 0-3 years
are eligible through "early intervention."

The influence of CP on development
Much of a child's normal intellectual, physical, and social
development occurs through play and exploration of the
environment. The ability to reach for and grasp objects, to
move about, to explore the properties of toys, and to
communicate with others are all central activities in the
child's growth. CP may restrict a child's ability to engage
in these activities, and therefore prevent the acquisition
of motor skills, knowledge of the world, and social
competence. The family can do much to overcome these
restrictions by adapting the child's environment to meet
his or her needs and providing challenges within the
child's abilities to accomplish. The advice and direction
of an occupational therapist can be critical to promoting
normal development of the child with CP.

Posture and mobility
Spasticity, muscle coordination, ataxia, and scoliosis are
all significant impairments that affect the posture and
mobility of a person with cerebral palsy. The physical
therapist works with the family to maximize the child's
ability to move affected limbs, to develop normal motor
patterns, and to maintain posture. Adaptive equipment may
be needed, including wheelchairs, walkers, shoe inserts,
crutches, or braces. The need for adaptive equipment may
change as the person develops, or as new treatments are
introduced. The parents or other caregivers are taught safe
transfer techniques to aid the person who cannot move
independently from wheelchair to bed, for example.

Spasticity
Spasticity causes muscles to shorten, joints to tighten,
and postures to change. Spasticity can affect the ability
to walk, use a wheelchair, and sit unaided; and it can
prevent independent feeding, dressing, hygiene, or other
activities of daily living. Contracture and dislocations
are common consequences of spasticity.

Mild spasticity may be treated by regular stretching of the
affected muscles through their full range of motion. This
usually is done at least daily. Moderate spasticity may
require bracing to keep the limb out of the abnormal
position, or serial casting to return it to its normal
position. Ankle-foot braces (orthoses) made of lightweight
plastic are often used to increase a child's stability and
to promote proper joint alignment. Before fixed contracture
develops, botulinum toxin (a highly active neurotoxin;
Botox) injections can help loosen the affected muscles.
Alcohol or phenol injection into the nerve controlling the
muscle is also done; these injections are less costly than
botulinum toxin, but they may cause more serious side
effects, including pain, loss of sensation, and excess
weakness. Fixed contractures are usually treated with
either serial casting or tenotomy surgery. In this surgery,
the tendons of the affected muscle are cut. The limb is
then cast in a more normal position while the tendon
regrows. Tenotomy is commonly done to prevent hip
dislocation and to correct equinus. Another type of surgery
available is dorsal rhizotomy. In this procedure, selected
nerve roots in the spinal cord are cut to prevent them from
stimulating the spastic muscles.


Spasticity may also be treated with muscle relaxing drugs,
including diazepam (Valium), dantrolene (Dantrium), and
baclofen (Lioresal). A baclofen pump can also be implanted
to deliver the drug directly to the spinal cord, its site
of action, allowing more effective spasticity reduction
with fewer side effects.

A variety of experimental surgeries have been tried for
people with cerebral palsy, most often to control
spasticity. Most of these have not proved effective for
most people. A new procedure implants an electrode into the
brain to control the tremors found in some forms of CP, but
as of 1998 the procedure was too new for its success to be
fully evaluated.

Ataxia and coordination
Ataxia, or lack of balance control, is another factor
affecting mobility. Physical therapy is an important tool
to help the child with CP maximize balance. Coordination
can be worsened if one member of a muscle pair is overly
strong; bracing or surgical transfer of the muscle to a
less overpowering position may help.

Scoliosis
Scoliosis, or spine curvature, can develop when the muscles
that hold the spine in place become either weak or spastic.
In either case, an imbalance of forces pulls the vertebrae
(bones making up the spinal column) out of alignment. This
can cause pain, as well as interfere with normal posture
and internal organ function. Scoliosis may be treated with
a trunk brace. If this proves unsuccessful, spinal fusion
surgery may be needed to join the vertebrae together, which
keeps the spine straight.

Seizures
Seizures occur in 30-50% of children with CP. Seizures may
be restricted to one limb (focal) or generalized. Grand mal
seizures are the most common type of generalized seizure
for people with CP. Seizures may be treated with drugs,
most commonly carbamazepine (Tegretol) or ethosuximide
(Zarontin). A combination of a ketogenic diet and fasting
may also be used to control seizures. Although the need for
antiseizure medication is temporary in some children, it
may be required throughout life for others.

Strabismus
Strabismus occurs in nearly half of all people with spastic
CP. Strabismus may be treated with patching and corrective
lenses. When these do not work, it may be treated with
either surgery on the eye muscles causing the problem or by
injection of botulinum toxin.

Nutrition
The person with CP may not be able to feed easily, because
of poor coordination of the tongue and mouth muscles, or
inability to hold and move utensils independently. The
person may not take in adequate nutrition for full growth
and development, worsening the results of the disorder.
Careful attention to nutritional needs can prevent these
problems. Nutritional supplements may be needed. Poor
swallowing coordination may lead to aspiration, or inhaling
of food or saliva. A speech-language therapist may be able
to teach the person more effective movement patterns to
avoid aspiration. In severe cases, a gastrostomy tube may
be required to provide adequate nutrition directly into the
digestive system while preventing aspiration. Nutrition may
need to be monitored throughout childhood and adolescence,
since meeting the increased food demands of a growing body
may become difficult.


Other common medical problems
Drooling, dental caries (cavities), and gum disease are
more common in people with CP than in the general
population, partly because of lowered coordination and
increased muscle tightness in the mouth and jaw. Each of
these can be prevented to some degree, either through
behavioral changes alone or in combination with drug
therapy. Constipation is more common as well, and may be
treated through dietary changes, or with enemas or
suppositories when necessary.

Communication
Poor coordination of the tongue and mouth muscles can also
affect speech. The inability to be understood can influence
the child's intellectual development, especially if parents
don't take the extra time needed to understand their
child's attempts at speech. Children may benefit from
picture boards or other communication devices that allow
them to point to make their desires known. For school-age
children or older persons with CP, there are a large number
of augmentative communication devices, including shorthand
typing programs and computer-assisted speech devices. A
speech-language therapist can offer valuable advice on the
types of equipment available.

Education
The best choice of school for the child with CP depends on
the presence and degree of mental impairment and physical
impairment, as well as the facilities available in the
area. "Inclusion," or mainstreaming the child in a regular
public school classroom, may work well for the child with
mild physical impairment. Separate classrooms or special
schools may be needed for more severely involved children.
Schooling for disabled students is governed by the
Individuals with Disabilities Education Act (IDEA) at the
federal level and state special education rules at the
local level. An educational specialist either within the
school system or from the community social services agency
may be able to help the family navigate the various
bureaucratic pathways that will ensure the best schooling
available.

The process of developing an educational plan for a child
with CP begins with an assessment of the child's needs. The
assessment is carried out under state guidelines by a team
of medical professionals. After the assessment, the school
district works with the parents and others involved in the
child's education and treatment to develop an
Individualized Educational Plan (IEP). The IEP states the
child's specific needs for special instruction and
indicates what services will be provided. The special
services may be as simple as allowing extra time to travel
between classes or as extensive as individualized
instruction, adapted classroom equipment, and special
testing procedures. More information about assessments and
IEPs is available through the National Information Center
for Children and Youth with Disabilities. The United
Cerebral Palsy Assocation is another resource for advocacy,
information, and legal rights.

Behavioral and mental health services


The child with CP may have behavioral problems or emotional
issues that affect psychological development and social
interactions. These may require special intervention or
treatment, including behavior modification programs or
individual and family counseling. Attention-
deficit/hyperactivity disorder is common in children with
CP, and may require behavioral, educational, and medical
intervention.

Alternative treatment
A number of people with cerebral palsy, both children and
adults, have found systematic relief and enhanced quality
of life from a combination of alternative and complementary
treatments, including homeopathy, massage therapy, vitamin
treatments, herbal medicine, and acupuncture.

Prognosis
Cerebral palsy can affect every stage of maturation, from
childhood through adolescence to adulthood. At each stage,
the person with CP and his or her caregivers must strive to
achieve and maintain the fullest range of experiences and
education consistent with the person's abilities. The
advice and intervention of professionals remains crucial
for many people with CP.

Although CP is not a terminal disorder, it can affect a
person's lifespan by increasing the risk of infection,
especially lung infections. Poor nutrition can contribute
to the likelihood of infection. People with mild cerebral
palsy may have near-normal lifespans. The lifespan of those
with more severe forms, especially spastic quadriplegia, is
often considerably shortened. However, over 90% of infants
with CP survive into adulthood.

Prevention
The cause of most cases of CP is unknown, but it has become
clear in recent years that birth difficulties are not to
blame in most cases. Rather, developmental problems before
birth, usually unknown and generally undiagnosable, are
responsible for most cases. Although the incidence of CP
caused by Rh factor incompatibility has declined markedly,
the incidence of CP as a consequence of prematurity has
increased, because of the increasing success of medical
intervention in keeping premature babies alive.

The risk of CP can be decreased through good maternal
nutrition, avoidance of drugs or alcohol during pregnancy,
and prevention or prompt treatment of infections. Recent
preliminary research suggests that magnesium sulfate may
reduce the risk of CP in mothers taking it for the medical
treatment for preeclampsia and preterm labor.

Key Terms
Ataxic
Ataxic refers to a condition called ataxia, in which
balance and coordination are impaired.
Athetoid
Athetoid refs to a condition called athetonia, which is
marked by slow, writhing, involuntary muscle movements.
Attention-deficit/hyperactivity disorder
A behavioral disorder marked by inattentiveness,
hyperactivity, and impulsivity.
Augmentative communication devices
Computers, picture boards, and other devices that increase
the ability to communicate, either with or without speech.


Contracture
A shortening of a muscle caused by an imbalance of force
between opposing muscles.
Diplegia
Paralysis of corresponding parts on both sides of the body.
Dorsal rhizotomy
Surgical procedure that cuts nerve roots to reduce
spasticity in affected muscles.
Dystonic
Dystonic refers to a condition called dystonia, in which
fine motor control is confused.
Equinovarus
A condition in which the foot is commonly pulled inward.
Equinus
The most common postural deformity.
Hemiplegia
Paralysis of one side of the body.
Hypotonic
Hypotonic refers to a condition called hypotonia, in which
fine motor control is floppy, without tone.
IEP
Individualized Educational Plan; a plan that guides the
delivery of services to a child with special education
needs.
Ketogenic diet
A specialized diet designed to increase the blood levels of
breakdown products known as ketone bodies. For unknown
reasons, this aids in seizure control.
Perinatal asphyxia
Asphyxia that occurs during birth.
Quadriplegia
Paralysis of all four limbs.
Serial casting
A series of casts designed to gradually move a limb into a
more functional position_as opposed to doing it all at once
with one cast, as would be done in setting a broken bone.
Spastic
Spastic refers to a condition in which the muscles are
rigid, posture may be abnormal, and fine motor control is
impaired.
Tenotomy
Surgical procedure that cuts the tendon of a contractured
muscle to allow lengthening.
Further Reading
For Your Information
Books
Kramer, Laura. Uncommon Voyage: Parenting a Special Needs
Child in the World of Alternative Medicine. Faber & Faber,
1996.
Miller, Freema, and Steven J. Bachrach. Cerebral Palsy: A
Complete Guide for Caregiving. Johns Hopkins University
Press, 1995.
Vickers, Andrew. Health Options: Complementary Therapies
for Cerebral Palsy and Related Conditions. Element
Publications, 1994.
Periodicals
Exceptional Parent Magazine 555 Kinderkamack Road, Oradell,
NJ 07649-1517; 800-EPARENT, 201-634-6550.
Kuban, KCK, and A. Leviton. "Cerebral Palsy." New England
Journal of Medicine 1994: 188-95.
Organizations
National Information Center for Children and Youth with
Disabilities. PO Box 1492, Washington DC 20013-1492. (800)
695-0285.
United Cerebral Palsy Association. 1660 L Street, NW
Washington, DC 20036-5602. (800) USA-5-UCP, (202) 776-0406,
(202) 973-7197 (TTY). (202) 776-0414 (fax).
[email protected] http://www.ucpa.org.
Other
Electronic forum for cerebral palsy http://neuro-
www.mgh.harvard.edu/forum/CerebralPalsyMenu.html.

Gale Encyclopedia of Medicine. Gale Research, 1999.