Brain Lesions in Intrauterine Growth Restriction Assessed by Ultrasound Imaging: Focus on US Technique and Periventricular Lesions

Abstract

Intrauterine growth-restricted infants constitute a vulnerable population, theoretically at increased risk for brain damage and adverse neurological outcomes. This condition may have specific adverse consequences on brain development, leading to structural and functional brain changes. These adjustments are probably a response against an adverse environment and may lead to a specific pattern of hypoxic-ischemic and/or hemorrhagic ultrasound lesions of distinct severity mainly involving the white matter. Although the results of several studies on abnormal cranial ultrasound findings including hypoxic-ischemic/hemorrhagic lesions are conflicting, the major involvement of intrauterine growth-restricted infants is evident. In addition to periventricular leukomalacia (PVL), transient periventricular echodensities should also be included in the diagnosis of white matter damage. This ultrasound finding has long been considered to have no clinical relevance, but recent reports suggest that transient periventricular echodensities should be regarded as part of the spectrum of white matter damage, since these echodensities might be associated with neurodevelopmental difficulties. Recent long-term postnatal studies have demonstrated that intrauterine growth restriction is specifically associated with significant neurodevelopmental deficits that cannot be attributed to prematurity alone. Neuropsychological alterations appear to particularly affect cognitive functions, suggesting an increased prevalence of white matter injury. The early detection of hypoxic-ischemic and/or hemorrhagic lesions as well as their follow-up through serial cranial ultrasound allows early interventional strategies for improved developmental outcome to be established.