ABSTRACT
In essence, the pathology from mid-gestation through infancy reflects cellular and tissue reactions brought about by a complex interplay of disease and rapidly changing developmental processes. Good evidence indicates that the most vulnerable time for cortical injury is toward the end of the gestational period, perhaps including the perinatal period, whereas the time associated with the greatest capacity for plasticity is 1 to 2 years of age.297 The developmental changes occur so rapidly that responses to the same insult may vary considerably from mid-gestation through infancy, as demonstrated by hypoxic-ischaemic injury to cerebral white matter preferentially in the preterm infant and to grey matter preferentially after the neonatal period. Moreover, different types of brain lesion may be restricted to very specific time periods within this overall period (Figure 3.2). This latter phenomenon is due in part to the rapid changes in peak periods of maturation of different cellular and molecular components of the brain, e.g. the peak occurrence of neuronal migration and differentiation in early gestation compared with the peak period of myelination in infancy. The focus upon the period from mid-gestation to
Introduction ...............................................................................210 Approach to Evaluation of Perinatal Specimens ..........................213 Brain Growth .............................................................................214 Cellular Components of the Developing Human Central Nervous System ......................................................................................216 Hypoxic-Ischaemic Injury to the Developing Brain ......................227 Grey Matter Lesions ...................................................................232 White Matter Lesions .................................................................235 Combined Grey and White Matter Lesions ..................................239
