Temporaryary Enlargement of the Subarachnoid Space in Very Premature Infants

The authors used a high-frequency, 10-MHz ultrasound transducer to improve near field details on cranial ultrasound scans to detect enlargement of the subarachnoid space without ventriculomegaly on the first day of life in 14 of 17 premature infants on mechanical ventilation for respiratory distress syndrome secondary to lung immaturity and in 1 of 9 premature infants with mild or no respiratory problems. Factors correlated with this finding were a birth weight of less than 1250 g (P < 0.05), gestational age of 28 weeks or less (P < 0.02), presence of respiratory distress (P < 0.01), and necessity of mechanical ventilation (P < 0.001). Enlargement of the subarachnoid space regressed completely during the neonatal period. Enlargement of the subarachnoid space in very premature infants is indicative of brain immaturity.