Lateral ventricular effacement as an isolated sonographic finding in premature infants: prevalence and significance

The sonographic finding of effaced lateral ventricles in premature infants, defined as the absence of visible CSF within the lateral ventricles on both coronal and sagittal sonograms, may be cause to suspect diffuse cerebral edema, especially as published reference standards do not address this phenomenon. This investigation was undertaken to determine the prevalence and significance of effaced lateral ventricles without associated parenchymal abnormality (isolated lateral ventricular effacement, or ILVE) in premature infants.

Sonographic records of 398 consecutive newborns examined from January 1 to December 31, 1993, were reviewed retrospectively to identify those premature infants (< 36 weeks of gestational age) whose initial sonograms showed no evidence of intracranial hemorrhage, ventriculomegaly, structural abnormality, or abnormal parenchymal echogenicity. We identified 142 neonates who met these criteria. Patients were separated into two groups on the basis of whether they had at least one sonographic study in which CSF was not visible within both lateral ventricles on coronal and sagittal images. Medical records were reviewed to assess neurologic outcome.

Forty patients (28%) had at least one sonogram demonstrating ILVE, with neurologic follow-up in 33 (representing group A). One hundred two patients (72%) never demonstrated ILVE, with neurologic follow-up established in 86 (representing group B). A comparison of the two groups showed no significant difference in the development of ischemic injury (one patient in each group). ILVE was first detected on the initial sonogram obtained (mean, 4 days) in 30 of the 33 neonates in group A. ILVE was demonstrated beyond the seventh day of life in 30%. Of the 89 patients whose initial sonograms showed CSF in the lateral ventricles (86 in group B and three in group A), three (3%) subsequently had sonograms that showed ILVE; all three were normal at follow-up.

ILVE in premature infants is common and not associated with neurologic deficits indicative of hypoxic-ischemic encephalopathy. By itself, ILVE is not a significant finding.