Diagnosis of Cerebral Palsy
Since cerebral palsy is not one diagnosis but instead includes a spectrum of disorders with a variety of physical findings, presentations and causes, it is not surprising that a specific diagnosis can sometimes be a challenge. Studies found that of those with cerebral palsy, approximately 30-40 percent had prenatal, 30-40 percent perinatal and 5 percent postnatal onset.
History Findings and Risk Factors
History findings and risk factors for cerebral palsy may include: maternal factors (mental retardation, epilepsy, hyperthyroidism, prior fetal deaths, twin pregnancy), sibling with motor problems, infections, toxins, prematurity, low birth weight, bleeding in the brain, seizures, low Apgar score (reflects condition of newborn), third-trimester bleeding, pre-eclampsia (maternal hypertension with protein in urine), premature placenta separation, low placenta weight, asphyxia/hypoxia (lack of oxygen), abnormal fetal position at birth, congenital malformations, fetal bradycardia (slow heart rate), hyperbilirubinemia (increased levels of bilirubin, a breakdown product of red blood cells), trauma and clotting disorders
However, most children do not necessarily present with these risk factors. A large study called the National Collaborative Perinatal Project looked at high risk factors and found that 97 percent of those with the high-risk profile will not end up having cerebral palsy, and 63 percent of children who end up with a diagnosis of cerebral palsy will not have a high-risk profile. The risk factors studied included a birth weight less than 2500 grams, gestation less than 32 weeks, intrauterine growth retardation, intracranial hemorrhage (bleeding in the brain) and trauma. Having a single risk factor has much less of an impact than having more than one factor.
Eight percent of infants born between 22 and 32 weeks gestation develop cerebral palsy with the prevalence increasing with decreased gestational age. Four percent of infants born at 32 weeks gestation develop cerebral palsy and 20 percent of infants born at less than 27 weeks gestation develop cerebral palsy. If children have bilateral cystic periventricular leukomalacia (brain injury from decreased blood flow), 75 percent of them will develop cerebral palsy.
In the 1800s, Freud first described an increased risk of cerebral palsy in multiple births. Twins are 1.6 percent of all births but 5 to 10 percent of children with cerebral palsy, with a relative risk of five times for a twin versus a single birth. Babies who are born as triplets have 12.7 times the risk of cerebral palsy. This is partly due to the smaller birth weight of multiple birth babies. Babies less than 1500 grams are less than 1 percent of single births, 10 percent of twins, 32 percent of triplets and 73 percent of quadruplets. Twins who are monozygotic are smaller than those who are dizygotic. The fetal death of a twin has been associated with severe problems of the surviving co-twin, including cerebral palsy, which is more common with twins who were monochorionic.
