Neurophysiological observations in diseased newborns.

The early statements that the EEG alone could correctly be used for the assessment of gestational age (cf., among others, Dreyfus-Brisac, 1964; Parmelee et al., 1968; and Nolte et al., 1969), even in pathological babies, need some restrictive qualifications. Likewise, the more recent statements that certain neurophysiological parameters, including nerve conduction velocity and basic EEG patterns are independent not only of gestational age and body weight, but also of various abnormal factors in the pre- and perinatal periods, appear also too rigid, at least as regards the EEG and the other parameters used in this study. As a matter of fact, some authors who had adhered rather strictly to these concepts have later on presented evidence suggesting some deviations in bioelectric brain maturation in some cases, as for example, in small-for-date newborns of toxemic mothers (Schulte et al., 1972). When more exact quantification by coding techniques was applied (Parmelee et al., 1968), the conclusion was also reached that extrauterine and intrauterine development of bioelectric brain activity developed according to the conceptional age, regardless of variable extrauterine experience, although it was recognized that other categories of behavioral and neurophysiological activities, for example, Moro reflex, states stability, crying, sucking, scores, etc., are more labile to environmental and pathological factors (Prechtl et al., 1972; Michaelis et al., 1973).