Variability of resistive indices in the anterior cerebral artery during fontanel compression in preterm and term neonates measured by transcranial duplex sonography

Abstract

To determine the normal range of resistive index (RI) variability in clinically/neurologically unremarkable preterm and term infants and to compare the hemodynamic response to transient elevation of intracranial pressure. We measured RIs at baseline and following brief fontanel compression, assessing for differences in mean baseline and compression values and percent change. One hundred and twenty-nine subjects were included in the study. Mean baseline RI and normal range were 0.7 in preterm (0.54 to 0.86) and 0.66 in term infants (0.52 to 0.8; P=0.001). Mean RI during compression was 0.71 in preterm and 0.68 in term infants (P=0.015). Mean percent change between baseline and compression was 5.86% in preterm and 7.45% in term infants (P=0.092). No difference in the hemodynamic response to transient elevation of intracranial pressure between different gestational groups, suggesting no significant differences in autoregulatory response.