Cerebral palsy refers to a group of disorders that involve loss of movement or loss of other nerve function.
Cerebral palsy is caused by injuries to the cerebrum (the largest part of the brain), which occur as the baby grows in the womb or near the time of birth.
Initially cerebral palsy was thought to be related to trauma and strangulation during birth (birth asphyxia), which leads to lack of oxygen to the brain), but in a study of 45,000 births it was shown that birth asphyxia is an uncommon cause of cerebral palsy.
In patients with cerebral palsy, parts of the brain areas receive lower levels of oxygen (hypoxia) at some point, but it is not known why this occurs.
Premature infants have a slightly higher rate of cerebral palsy. Cerebral palsy may also occur during early infancy as a result of illnesses (encephalitis, meningitis, herpes simplex infections, and so on), head injury that results in subdural hematoma, blood vessel injuries, and many others conditions.
Injury to the cerebrum can result in the loss of nerve functions in widely different areas. The classical finding of CP is increased muscle tone ( spasticity ). Spasticity may affect:
- One arm or leg
- One side of the body (spastic hemiplegia)
- Both legs (spastic diplegia)
- Both arms and legs (spastic quadriplegia)
In addition, the child may have a partial or full loss of movement (paralysis), problems hearing and vision, and sensation abnormalities. Speech problems are common.Seizures may occur.
Intellectual function may range from extremely bright normal to severe mental retardation. Symptoms are usually seen before age 2. In severe cases, they may appear as early as 3 months.
Classifications of cerebral palsy include spastic, dyskinetic, ataxic, and mixed.
- Spastic cerebral palsy is the most common type.
- Dyskinetic (athetoid) cerebral palsy involves development of abnormal movements (twisting, jerking, or other movements).
- Ataxic cerebral palsy involves tremors, unsteady gait, loss of coordination, and abnormal movements.
- Mixed cerebral palsy involves any combination of symptoms.
Cerebral palsy is a lifelong disorder. Long-term care may be required. The disorder does not affect expected length of life. The extent of disability varies.
Cerebral Palsy is neither contagious nor progressive. When someone who has Cerebral Palsy dies, it is not the CP itself that has caused the death. Rather, it is the result brain damage that has occurred in another area of the brain. There are several disorders associated with Cerebral Palsy, as the brain damage is typically not restricted to the motor centers of the brain.
There are several classifications of CP. One does not simply have CP. This usually begins with how the muscles are affected. The Spastic type is when there are exaggerated stretch reflexes, increased deep tendon reflexes and muscle spasm. Secondly, is the Athetiod type wherein there is purposeless, uncontrollable movements and muscle tension. Finally there is Atactic which leaves the child with poor balance, poor coordination and gait. You may hear these simply described as either being tight (spastic) or floppy (Atactic). Athetiod may also be characterized as writhing movements.
Your child may have one or more types. Usually this presents as a Spastic-Athetiod combination. These types may also change over the years. Most frequently this is either from a singular type to a combination, either Spastic or Athetiod to a Spastic Athetiod combination or Atatic to an Atactic-Athetiod. It is also possible that a Spastic child may become predominately Athetiod, or vice versa. A child going from Spastic to Atactic will almost never occur.
With these classifications then comes the location. This can be diplegia, affecting like extremities (both arms or both legs): hemiplegia, affecting one side (the opposite side of brain injury): triplegia, affecting three extremities or quadriplegia (tetraplegia) affecting all four extremities.
Additionally, to further confuse the issue, CP is given a severity level: mild, moderate or severe.
The end result gives you something like this:
Severe Spastic-Athetiod Quadriplegic Cerebral Palsy
Or
Severe Quadriplegic (Quadriplegia) Cerebral Palsy of the Spastic-Athetiod type.
The different types are treated in different manors and certain types are apt to be more severe in general.
Above the hips, persons with spastic diplegia typically retain normal or near-normal muscle tone and range of motion, though some lesser spasticity may also affect the upper body, such as the trunk and arms, depending on the severity of the condition in the individual. Additionally, because leg tightness often leads to instability in ambulation, extra muscle tension usually develops in the upper body, shoulders, and arms due to compensatory stabilization movements, regardless of the fact that the upper body itself is not directly affected by the condition. Meanwhile, lower-extremity spasticity in spastic diplegia is rarely so great as to totally prevent ambulation — i.e., most people with the condition can walk — but the main difference between spastic diplegia and a normal gait pattern is that spastic diplegia does result in the signature "scissor gait" that some able-bodied people might tend to confuse with the effects ofdrunkenness, multiple sclerosis or another nerve disease.
Causes
Doctors aren't sure what causes CP. This matter has been debated over the years with no obvious answers or conclusions.
Some causes of CP are asphyxia, hypoxia of the brain, birth trauma, premature birth, and certain infections in the mother during and before birth such as strep infections, central nervous system infections, trauma, consecutive hematomas, and placenta abruptio.
Between 40% and 50% of all children who develop cerebral palsy were born prematurely. Premature babies have a higher risk in part because their organs are not yet fully developed. This increases the risk of asphyxia and other injury to the brain, which in turn increases the incidence of CP. Periventricular leukomalacia is an important cause of CP.
Recent research has demonstrated that intrapartum asphyxia is not the most important cause, probably accounting for no more than 10 percent of all cases; rather, infections in the mother, even infections that are not easily detected, may triple the risk of the child developing the disorder, mainly as the result of the toxicity to the fetal brain of cytokines that are produced as part of the inflammatory response.[1]
The risk of a baby having CP increases as the birth weight decreases. A baby who is born prematurely usually has a low birth weight, less than 5.5 lb, but full-term babies can also have low birth weights. Multiple-birth babies are more likely than single-birth babies to be born early or with a low birth weight.
After birth, the condition may be caused by toxins, severe jaundice, lead poisoning, physical brain injury, shaken baby syndrome, incidents involving hypoxia to the brain (such as near drowning), and encephalitis or meningitis. The three most common causes of asphyxia in the young child are: choking on foreign objects such as toys and pieces of food; poisoning; and near drowning.
Some structural brain anomalies such as lissencephaly cause symptoms of CP, although whether that could be considered CP is a matter of opinion (some people say CP must be due to brain damage, whereas these people never had a normal brain). Often this goes along with rare chromosome disorders and CP is not genetic or hereditary.
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