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.

• Seizures
• Muscle contractions
• Difficulty sucking or feeding
• Irregular breathing
• Delayed development of motor skills, such as reaching, sitting, rolling, crawling, walking, and so on
• Motormental retardation
• Mental retardation
• Speech problems (dysarthria)
• Visual problems
• Hearing problems
• Spasticity
• Joint contractures that slowly get worse
• Limited range of motion
• Peg teeth

In many cases, a doctor's examination indicates delayed development of motor skills. Infantile reflexes (such as sucking and startle) may persist past the age where they usually disappear. Muscle tremor or spasticity may be evident, with a tendency of infants to tuck their arms in toward their sides, scissors movements of the legs, or other abnormal movements.

Various laboratory tests may be performed to eliminate nutritional or other causes of the symptoms.

• MRI of the head demonstrates structural or congenital abnormalities
• CT scan of the head demonstrates structural or congenital abnormalities
• Hearing screen (to determine auditory status)
• Visual testing (to determine visual status)
• EEG
• Blood tests to exclude metabolic or hereditary conditions