When CP is diagnosed in childhood, it is often found that the child suffered asphyxia at birth.  The asphyxia, however, is often considered the symptom of an otherwise sick baby with a neurological problem, not the primary cause of CP.  In two different, large studies, only about 9 percent of children with CP were thought to have CP directly and exclusively related to asphyxia at delivery.  Ninety-one percent of babies had other inherent causes that led to prematurity or neonatal problems (problems occurring at birth or right after birth).  (Bachrach and Miller)

Apgar scores are used to determine the vulnerability of an infant to cerebral palsy and severe birth trauma.  Respiration, heart rate, muscle tone, skin color, and motor reaction time are evaluated to determine an Apgar score.  The lower the score, the greater the risk.  Twenty minutes after birth, a score of three gives an infant 250 times greater risk than a normal score and suggests the possibility of severe asphyxia.  (Seven to ten is a normal Apgar score.)  Only half of the infants with such low Apgar scores 20 minutes after birth develop cerebral palsy.  This statistic calls attention to the difficulty of associating the events of asphyxia at birth with specific outcomes as the infant matures.

It is not easy to correlate cerebral palsy with cellular events, such as cerebral oxygenation.  The task is profoundly complicated by possible variables noted on the other pages of this website, such as infection, genetic issues, the mother’s state of health, etc.

Periventricular leukomalacia (PVL) describes cell death in the white matter of the brain beside the lateral ventricles.  It can result from both reduced blood oxygen and reduced blood flow to the brain.  It is associated with reduced use of the legs.  Intraventricular hemorrhage (IVH) is bleeding into the ventricles.  Periventricular leukomalacia and intraventricular hemorrhage are two conditions that can result in a reduction in blood supply (hypoxia), yet it is often difficult to estimate if cerebral palsy will result.  A relatively small area of damage may result in long-term repercussions.  Both MRI and cranial ultrasound are relied upon to make these evaluations.  But cerebral palsy is diagnosed when the symptoms appear, not when damage occurs that later leads to cerebral palsy.

Bachrach, Steven J., and Miller, Freeman.  Cerebral Palsy: A Complete Guide for Caregiving.  Baltimore: The Johns Hopkins University Press, 1995.

Hart, Hilary M., ed.  Clinics in Developmental Medicine.  London:  Mac Keith Press.   Alberman, Eva; Blair, Eve; and Stanley, Fiona.  Cerebral Palsies: Epidemiology and Causal Pathways.  London:  Cambridge University Press, 2000.  (The book is part of a series of hardcover monographs published by Mac Keith Press.  Four new ones are published each year.  The distributor is Cambridge University Press.)