Michael V. Johnston* and Alexander H. Hoon, Jr.
Kennedy Krieger Institute and Departments of Neurology and Pediatrics, Johns Hopkins University School of Medicine, 707 NorthBroadway, Baltimore, MD 21205
Received February 1, 2006; Accepted March 8, 2006
Cerebral palsy (CP) is a group of disorders of movement and posture resulting from nonprogressivedisturbances of the fetal or neonatal brain. More than 80% of cases of CP in term infants originate in the prenatal period; in premature infants, both prenatal or postnatal causes contribute. The most prevalentpathological lesion seen in CP is periventricular white matter injury (PWMI) resulting from vulnerability of the immature oligodendrocytes (pre-OLs) before 32 wk of gestation. PWMI is responsible forthe spastic diplegia form of CP and a spectrum of cognitive and behavioral disorders. Oxidative stress and excitotoxicity resulting from excessive stimulation of ionotropic glutamate receptors onpreOLs are the most prominent molecular mechanisms for PWMI. Asphyxia around the time of birth in term infants accounts for less than 15% of CP in developed countries but the incidence is higher inunderdeveloped areas. Asphyxia causes a different pattern of brain injury and CP than is seen after preterm injuries. This type of CP is associated with the clinical syndrome of hypoxic–ischemicencephalopathy shortly after the insult, and the cortex, basal ganglia, and brainstem are selectively vulnerable to injury. Experimental models indicate that neurons in the neonatal brain are more likely to dieby delayed apoptosis extending over days to weeks than those in the adult brain. Neurons die by glutamate-mediated excitotoxicity involving downstream caspase-dependent and caspase-independent cell...