Cerebral Palsy Causes

Cerebral palsy is not a disorder with a single cause, like chicken pox or measles. It is a group of disorders with similar problems in control of movement, but probably with a variety of causes.

Congenital cerebral palsy, results from brain injury during intra-uterine life. It is present at birth, although it may not be detected for months. It is responsible for about 70% of children who have cerebral palsy. An additional 20 % are diagnosed with congenital cerebral palsy due to a brain injury during the birthing process. In most cases, the cause of congenital cerebral palsy is unknown.

One the other hand, in the United States, about 10 percent of children who have cerebral palsy acquire the disorder after birth. (The figures are higher in underdeveloped countries.) Acquired cerebral palsy results from brain damage in the first few months or years of life and can follow brain infections, such as bacterial meningitis or viral encephalitis, or the results of head injury -- most often from a motor vehicle accident, a fall, or child abuse.

A large number of factors, which can injure the developing brain, may produce cerebral palsy. A risk factor is not a cause; it is a variable which, when present, increases the chance of something occurring -- in this case, cerebral palsy. Just because a risk factor is present does not mean cerebral palsy WILL occur; nor does the absence of a risk factor mean that cerebral palsy will NOT occur. If a risk factor is present, it serves to alert parents and physicians to be even more observant to the infant's development.

Risk factors for cerebral palsy include the following: premature birth; low birth weight; inability of the placenta to provide the developing fetus with oxygen and nutrients; lack of growth factors during intra-uterine life; RH or A-B-O blood type incompatibility between mother and infant; infection of the mother with German measles or other viral diseases in early pregnancy; bacterial infection of the mother, fetus or infant that directly or indirectly attack the infant's central nervous system; prolonged loss of oxygen during the birthing process and severe jaundice shortly after birth.

We do not know the cause of most cases of cerebral palsy. That is, we are unable to determine what caused cerebral palsy in most children who have congenital cerebral palsy. We do know that the child who is at highest risk for developing cerebral palsy is the premature, very small baby who does not cry in the first five minutes after delivery, who needs to be on a ventilator for over four weeks, and who has bleeding in his brain. Babies who have congenital malformations in systems such as the heart, kidneys, or spine are also more likely to develop cerebral palsy, probably because they also have malformations in the brain. Seizures in a newborn also increase the risk of cerebral palsy. There is no combination of factors which always results in an abnormally functioning individual. That is, even the small premature infant has a better than 90 percent chance of not having cerebral palsy. There are a surprising number of babies who have very stormy courses in the newborn period and go on to do very well. In contrast, some infants who have rather benign beginnings are eventually found to have severe mental retardation or learning disabilities.