Cerebral Palsy Health Article

Cerebral Palsy

A permanent motor disability caused by brain damage associated with birth.

Cerebral palsy (CP) results from head injury after birth. The primary effects of cerebral palsy range from mild impairment of movement of one part of the body to severe impairment of most gross and fine motor functions. CP can also cause sight and hearing impairments, problems with depth perception and balance, learning disabilities, and mental retardation. Motor problems associated with CP often impair a person's ability to walk, talk, eat, breathe, speak, and control bladder functions, and he or she must receive significant support to perform the daily functions of living.

Cerebral palsy occurs in about 2.5 of every 1,000 live births, so that between 500,00 and 750,000 people in the United States have the disorder. In 30-75% of cases the original cause is unknown. Many birth-related problems associated with CP, such as German measles, RH incompatibility, and asphyxiation during labor, have been nearly eliminated, yet the incidence of CP has not declined accordingly. Some suggest that the relative increase in incidence of CP may be due to increased survival of premature infants. Research has also linked in utero formation of brain cysts with CP.

CP is primarily a problem of planning and controlling movement. Any movement of the human body consists of a delicately timed and coordinated process of muscle contraction (shortening) and expansion (lengthening). For example, to perform the fairly simple act of raising the hand to touch the face, muscles in the front of the arm (biceps) contract and tighten as the muscles in back (triceps) expand and loosen. Lack of coordination of changes in the two muscles results in jerky movement. The act of stopping the movement is as important as initiating and coordinating it. CP is categorized both by the type of muscle affliction and by the location of afflicted muscles.

There are three main types of muscle affliction: spastic, ataxic, and athetoid. In spastic CP, the afflicted muscles are extremely tight. People with spastic CP have stiff and jerky movements and difficulty letting go of objects they are gripping. About half of all CP is spastic CP. By contrast, people with the much rarer atoxic CP have very loose muscles and experience problems holding onto things. Shakiness and difficulties with depth perception characterize ataxic CP. In athetoid CP the afflicted muscles are sometimes too tight and sometimes too loose. Due to random muscle expansions and contractions people with athetoid CP have trouble sitting or standing up and experience involuntary movement of the face, arms, and upper body. About 25% of people with CP have athetoid CP, and another 25% have a combination of forms.

When muscles on all four of the limbs (and usually the trunk and face) are afflicted by cerebral palsy, it is called quadriplegia. When only one side of the body is afflicted, it is called hemiplegia. When only the legs are afflicted or the leg muscles are more severely impaired than the arms, it is described as diplegia. The set of speech problems caused by difficulties moving the jaws, lips, and tongue in persons with quadriplegia is called dysarthria.