The degree of antenatal ventriculomegaly is related to pediatric neurological morbidity

Altered cleavage plane orientation with increased genomic aneuploidy produced by receptor-mediated lysophosphatidic acid (LPA) signaling in mouse cerebral cortical neural progenitor cells

The brain is composed of cells having distinct genomic DNA sequences that arise post-zygotically, known as somatic genomic mosaicism (SGM). One form of SGM is aneuploidy-the gain and/or loss of chromosomes-which is associated with mitotic spindle defects. The mitotic spindle orientation determines cleavage plane positioning and, therefore, neural progenitor cell (NPC) fate during cerebral cortical development. Here we report receptor-mediated signaling by lysophosphatidic acid (LPA) as a novel extracellular signal that influences cleavage plane orientation and produces alterations in SGM by inducing aneuploidy during murine cortical neurogenesis. LPA is a bioactive lipid whose actions are mediated by six G protein-coupled receptors, LPA₁-LPA₆. RNAscope and qPCR assessment of all six LPA receptor genes, and exogenous LPA exposure in LPA receptor (Lpar)-null mice, revealed involvement of Lpar1 and Lpar2 in the orientation of the mitotic spindle. Lpar1 signaling increased non-vertical cleavage in vivo by disrupting cell-cell adhesion, leading to breakdown of the ependymal cell layer. In addition, genomic alterations were significantly increased after LPA exposure, through production of chromosomal aneuploidy in NPCs. These results identify LPA as a receptor-mediated signal that alters both NPC fate and genomes during cortical neurogenesis, thus representing an extracellular signaling mechanism that can produce stable genomic changes in NPCs and their progeny. Normal LPA signaling in early life could therefore influence both the developing and adult brain, whereas its pathological disruption could contribute to a range of neurological and psychiatric diseases, via long-lasting somatic genomic alterations.

Early neurodevelopmental outcome in preterm posthemorrhagic ventricular dilatation and hydrocephalus: Neonatal ICU Network Neurobehavioral Scale and imaging predict 3-6-month motor quotients and Capute Scales

OBJECTIVE

Brain injury remains a serious complication of prematurity. Almost half of infants with severe intraventricular hemorrhage (IVH) develop posthemorrhagic ventricular dilatation (PHVD) and 20% need surgery for posthemorrhagic hydrocephalus (PHH). This population is associated with an increased risk of later neurodevelopmental disability, but there is uncertainty about which radiological and examination features predict later disability. In this study the authors sought to devise and describe a novel combination of neurobehavioral examination and imaging for prediction of neurodevelopmental disability among preterm infants with PHVD and PHH.

METHODS

The study patients were preterm infants (< 36 weeks gestation) with IVH and PHVD, with or without PHH. Ventricular index (VI), anterior horn width (AHW), thalamooccipital distance (TOD), ventricle/brain (V/B) ratio, and resistive indices (RIs) were recorded on the head ultrasound (HUS) just prior to surgery, or the HUS capturing the worst PHVD when surgery was not indicated. The posterior fossa was assessed with MRI. Neonatal ICU Network Neurobehavioral Scale (NNNS) examinations were performed at term age equivalent for each infant. A neurodevelopmental assessment using the Capute Scales (Capute Cognitive Adaptive Test [CAT] scores and Capute Clinical Linguistic Auditory Milestone Scale [CLAMS] scores) and a motor quotient (MQ) assessment were performed between 3 and 6 months of age corrected for degree of prematurity (corrected age). MQs < 50 reflect moderate to severe delays in early motor milestone attainment, CAT scores < 85 reflect delays in early visual and problem-solving abilities, and CLAMS scores < 85 reflect delays in early language.

RESULTS

Twenty-one infants underwent assessments that included imaging and NNNS examinations, Capute Scales assessments, and MQs. NNNS nonoptimal reflexes (NOR) and hypertonicity subscores and AHW were associated with MQs < 50: NOR subscore OR 2.46 (95% CI 1.15-37.6, p = 0.034), hypertonicity subscore OR 1.68 (95% CI 1.04-3.78, p = 0.037), and AHW OR 1.13 (95% CI 1.01-1.39, p = 0.041). PVHI, cystic changes, and neurosurgical intervention were associated with CAT scores < 85: PVHI OR 9.2 (95% CI 1.2-73.2, p = 0.037); cystic changes OR 12.0 (95% CI 1.0-141.3, p = 0.048), and neurosurgical intervention OR 11.2 (95% CI 1.0-120.4, p = 0.046). Every 1-SD increase in the NOR subscore was associated with an increase in odds of a CAT score < 85, OR 4.0 (95% CI 1.0-15.0, p = 0.044). Worse NNNS NOR subscores were associated with early language delay: for a 1-SD increase in NOR subscore, there was an increase in the odds of a CLAMS score < 85, OR 19.5 (95% CI 1.3-303, p = 0.034).

CONCLUSIONS

In former preterm children with severe IVH and PHVD, neonatal neurological examination findings and imaging features are associated with delays at 3-6 months in motor milestones, visual and problem-solving abilities, and language.

Presence of chromosomal abnormalities in fetuses with isolated ventriculomegaly on prenatal ultrasound in China

Background

The purpose of our study was to compare the incidence of chromosomal abnormalities of fetuses with isolated fetal ventriculomegaly (VM) to that of fetuses with the sole risk factor of being born to mothers of advanced age.

Method

This prospective study included two groups. Group 1 included fetuses with isolated VM and were further categorized according to maternal age, fetal gender, laterality of VM (unilateral or bilateral), evolution of VM (resolved or persistent or progressive), and the gestational age at the time of diagnosis (<28w or ≥28w). Group 2 were fetuses without any fetal structural abnormality, but maternal age was at or over 35 years.

Result

Eighteen fetuses (18/231, 7.8%) with chromosomal abnormalities were identified for Group 1, and 13 fetuses (13/782, 1.7%) were identified for Group 2. When cases with mothers of advanced age were excluded from Group 1, the incidence of chromosomal abnormalities of isolated VM fetuses age was 7.2%, which is still higher than that of normal structural fetuses in mothers of advanced age (p < 0.001).

Conclusion

The risk of chromosomal abnormalities for fetuses with isolated VM is high, especially when it is severe, bilateral, the first presence occurs in mid‐gestation and is not resolved.

A prospective study of fetuses with isolated ventriculomegaly investigated by antenatal sonography and in utero MR imaging

BACKGROUND AND PURPOSE

Fetal ventriculomegaly (VM) is important because of its high prevalence and high risk of association with other brain abnormalities. The purpose of this article was to investigate the hypotheses that including in utero MR imaging (iuMR) in the diagnostic pathway for fetuses with isolated VM on antenatal imaging will show other brain abnormalities in a high proportion of cases and that these will have a significant effect on clinical management.

MATERIALS AND METHODS

One hundred forty-seven pregnant women were recruited prospectively from 8 fetomaternal centers in Britain. All of the fetuses had VM diagnosed on sonography but no other abnormality. iuMR was performed, and the results of the examinations were compared with those of sonography. Two fetomaternal experts made independent assessments of the effects of any new diagnoses on clinical management.

RESULTS

Categoric assessments of ventricular size were the same in approximately 90% of fetuses. Other abnormalities were shown in 17% of fetuses. The most frequent additional brain abnormality shown on iuMR was agenesis of the corpus callosum. Severe VM was associated with an approximately 10-fold increase in the risk of another brain abnormality being present when compared with fetuses with mild VM. The most profound effects on clinical management, however, were found in cases of mild VM.

CONCLUSIONS

This work supports our hypotheses by showing a high detection rate of other brain pathology when iuMR was used to supplement antenatal sonography (17%). In a high proportion of cases, the detection of the extra pathology would have led to significant changes in clinical management.

Isolated mild fetal ventriculomegaly

Ventriculomegaly is an excess of fluid in the lateral ventricles within the developing cerebrum. It is usually diagnosed at a routine fetal anomaly scan at 18-22 weeks gestation. Management of the condition and counselling of parents are difficult, as the cause, absolute risk, and degree of resulting handicap cannot be determined with confidence.