Cerebral Palsy (CP) is a general term for disorders of movement and posture resulting from damage to a child's developing brain in the later months of pregnancy, during birth, in the newborn period, or in early childhood, thus affecting the child's developmental milestone. These disorders are nonprogressive (i.e. they do not increase in time).

It isn't a disease. The parts of the brain that control muscle movements are particularly vulnerable to injury in premature and young infants.

It affects 1 or 2 of every 1,000 infants but is 10 times more common in premature infants and is particularly common in very small infants. But the incidence may vary between countries.

Cerebral palsy is often not evident at birth, as all newborns have little control over their bodies. Their movements and actions are dominated by their primitive reflexes, automatic responses built into the nervous system. Primitive reflexes cause changes in both muscle tone and in movements of the limbs. As the brain matures, and an infant's development progresses, a normal baby gradually loses the primitive reflexes and gains increasingly fine voluntary control over the movements of the body's separate parts.

When the child has cerebral palsy, however, primitive reflexes persist beyond the usual 6 months of age, interfering with normal movement and significantly delaying motor development. The child has difficulty mastering such familiar landmarks of growth as sitting, rolling over, crawling, walking, smiling, or making speech sounds. The persistence of the primitive reflexes, even into adulthood, is a principal sign of cerebral palsy.

There are four main types of cerebral palsy:

Cerebral palsy interferes not only with the brain's function of controlling and coordinating movement but with the further development of a child's gross and fine motor skills, normally achieved a precise and delicate balance between voluntary and involuntary controls. An example of a gross motor skill is walking; an example of a fine motor skill is drawing. Although motor development is delayed, cognitive skills (perceiving, thinking, and remembering) and language skills may be unaffected and progress at a normal rate.

• Spastic - in which the muscles are stiff and weak -- occurs in about 70 percent of children with cerebral palsy
  • Diplegia - all four limbs are affected (legs are more affected than the arms); there is delayed development in many movement skills and has difficulty learning to walk; affected legs cross in scissorlike fashion

    

  • Hemiplegia - limbs on one side of the body are affected (arms are more affected than the leg); the affected limbs grow slowly; affected arm is tucked up at the side of the body with both elbow and wrist bent

    

  • Quadriplegia - all four limbs are severely affected, not necessarily symmetrical
• Choreoathetoid - in which the muscles spontaneously move slowly and without normal control -- occurs in about 20 percent of children with cerebral palsy
• Ataxic - in which coordination is poor and movements are shaky -- occurs in about 10 percent of children with cerebral palsy
• Mixed - in which two of the above types, most often spastic and choreoathetoid, are combined -- occurs in many children