Cortical maturation in fetuses referred for ‘isolated’ mild ventriculomegaly: a longitudinal ultrasound assessment

Abstract

Objectives To compare cortical maturation between fetuses with isolated mild ventriculomegaly (IMV) and healthy fetuses, and to explore its potential prognostic value in IMV.Methods This prospective study quantified cortical maturation by ultrasound in 24 fetuses with IMV and 46 healthy fetuses. Depth and grading the developmental pattern of the parieto-occipital fissure (POF), calcarine fissure (CF) and sylvian fissure, and grading the Sylvian fissure operculization at 23-25, 27-28 and 31-32 weeks gestation were determined.Results At 23-25 and 27-28 gestational weeks, POF and CF mean depths were statistically lower in the IMV group. The POF and CF depth distribution had a normal distribution in the control group but displayed a bimodal distribution in the IMV group. IMV with progression of ventricular dilatation showed mean depth of CF lower than IMV in which ventriculomegaly regressed or remained stable. The sensitivity, specificity, positive predictive value and negative predictive value of a CF depth below the fifth percentile to predict progression of ventricular dilatation were, at 28 weeks, 100%, 88%, 67% and 100%, respectively. ConclusionsCortical fissure assessment by ultrasound allowed the differentiation of a subgroup of IMV fetuses with a higher risk of progression of ventricular dilatation.

Altered cortical development in fetuses with isolated nonsevere ventriculomegaly assessed by neurosonography

“…On this regard, we demonstrated that calcarine sulcus was less deep in the hemisphere contralateral to ventricular dilation in those cases with unilateral dilation. Changes in parieto‐occipital and calcarine sulci have been previously related with ventricular enlargement, although the mechanism behind is still controversial . Decreased sulci depth could be related with a mechanical deformation due to ventricular dilation or may indicate an underdeveloped maturation due to altered neuronal proliferation and migration.…”

“…Evaluation of appearance of sulci in a nonselected population of mild fetal VM has shown significant delay of 2 weeks in MRI, being the absence of specific sulci associated with poorer prognosis . Regarding ultrasonography evaluation, an inverse relationship between ventricle size and calcarine depth that correlated to cases with later progression has been described . However, these studies did not quantify cortical maturation or only included few sulci in their evaluation missing other brain regions that could be also affected.…”

“…Few studies have explored changes in cortical development in isolated mild VM, but their results are contradictory. [18][19][20][21][22][23] Evaluation of cortical volumes by magnetic resonance imaging (MRI) has shown increased cortical volume in fetal period 18 and neonates, 24,25 which were persisting until 2 years of age. 19 However, in a cohort of early gestational age these differences could not be detected.…”

“…22 Regarding ultrasonography evaluation, an inverse relationship between ventricle size and calcarine depth that correlated to cases with later progression has been described. 23 However, these studies did not quantify cortical maturation or only included few sulci in their evaluation missing other brain regions that could be also affected. In addition, some of them have included severe cases and nonisolated cases, 2 conditions that can bias their results.…”

Reduced fetal brain fissures depth in fetuses with congenital heart diseases

“…Our previous studies using three‐dimensional US have shown that fetuses with CHD have smaller intracranial volumes and increased cerebral blood flow perfusion . Recent reports have suggested that routine two‐dimensional US could quantitatively assess fetal cortex maturation in terms of brain fissure depths . If this method could be used in fetuses with CHD, then the detection of cerebral maturation impairment in routine obstetrical scans would be simplified, and close prenatal follow‐up could be implemented.…”