Electrophysiological brain maturation in premature infants: an historical perspective.

The EEG is an excellent method for measuring brain maturation in premature neonates. Characteristic patterns typify each conceptional age (CA) (age in weeks from conception) and allow the experienced reader to predict within +/- 2 weeks the infant's CA. This paper reviews from an historical perspective (beginning with Berger) the dramatic changes the EEG undergoes from early premature birth (CA, 26 weeks) to term (CA, 40 weeks). The important features of normal EEG development are discussed as well as the clinical significance of an apparent arrest or delay of the normal developmental process, the so-called "dysmature" pattern. It is proposed that close attention to the stage of brain maturation in normal and abnormal EEGs might allow more accurate timing of the brain insult in infants with neurological sequelae.