Development of Early and Late Brainstem Conduction Time in Normal and Intrauterine Growth Retarded Children

Abstract

Development of early (I-III) and late (III-V) brainstem conduction time (BCT) in the brainstem auditory evoked responses was examined and compared in 178 appropriate-for-gestational-age (AGA) and 24 small-for-gestational-age (SGA) children from birth to 6 years of age. In AGA children, the III-V/I-III interval ratio increased with age from birth to 2 years and remained relatively steady. This indicates that the development of the early and late BCT, or probably the lower and upper brainstem is not synchronous during early childhood, with a slightly faster development of the early BCT relative to the late BCT. In SGA children, the I-V, I-III and III-V intervals showed similar developmental trends to those in AGA children. However, the III-V/I-III ratio followed a developmental course which differed remarkably from that in AGA children. The ratio decreased slightly with age up to 2 years and was consistently smaller than in normal children after 1 year, indicating that the relative development of early and late BCT deviates from normal. This finding suggests that prenatal factors responsible for intrauterine growth retardation could alter the late or long-term development of the nervous system, resulting in sub-optimal outcome.

Heart Rate and Heart Rate Variability during Sleep in Small-for-Gestational Age Newborns

“…Arguments for advanced development have been reported by Amiel-Tison (9), on the basis of neurologic examination, and by Pettigrew et al (30), on the basis of brainstern auditory evoked potentials. Some other data on brainstem auditory evoked response suggest a delay in brainstem maturation in SGA newborns (18,31). Finally, data on respiratory rate in QS (32), motor activity (5), and sleep state organization (6) showed that SGA newborns do not differ from AGA newborns.…”

Mild maturational delay of the brainstem at term in late preterm small-for-gestation age babies

“…There are a few authors who reported their BAER studies in SGA infants or children born at various gestations. Some of them found abnormalities (e.g., increase or shortening in wave latencies and interpeak intervals, although the others did not [14][15][16][17][18][19][20][21][22]). So far, there is no consensus with regard to the effect of SGA or IUGR on brainstem auditory function in infants.…”

Brainstem auditory-evoked responses to different rates of clicks in small-for-gestational age preterm infants at term

“…Since mid-1980 s brainstem auditory-evoked responses (BAERs) have been used as an objective tool to study neural function and its development in infants following intrauterine growth retardation (IUGR) (1)(2)(3)(4)(5)(6)(7)(8). However, previous BAER findings are varied.…”

“…In the previous studies the BAER was recorded with click stimuli at relatively low repetition rates (e.g. 10-21 s À1 ) (1)(2)(3)(4)(5)(6)(7)(8). Recent studies have shown that the use of higher rates to record the BAER can improve the detection of central auditory impairment in high-risk infants (12)(13)(14).…”