Cerebral palsy is not a specific disease entity but rather a collection of disabling disorders caused by insult and permanent damage to the brain in the prenatal and perinatal periods, during which time the central nervous system is still maturing. This disability might involve muscle weakness, stiffness, or paralysis, poor balance or irregular gait, and uncoordinated or involuntary movements. Although many recognized conditions result in damage to the motor centers of the brain, in at least one third of the cases of cerebral palsy, no discernible cause is found. It has been well established that any factor contributing to decreased oxygenation of the developing brain can be responsible for brain damage. In addition, causal relationships have been established between cerebral palsy and complications of labor or delivery; infections of the brain, such as meningitis and encephalitis; toxemias of pregnancy; congenital defects of the brain; kernicterus; poisoning with certain drugs and heavy metals; and accidents resulting in trauma to the head. There is a high correlation between premature birth and cerebral palsy.