Prognostic Analysis and Risk Factors Associated with Fetal Ventriculomegaly

The Conundrum of Mechanics Versus Genetics in Congenital Hydrocephalus and Its Implications for Fetal Therapy Approaches: A Scoping Review

Recent advances in gene therapy, particularly for single-gene disorders (SGDs), have led to significant progress in developing innovative precision medicine approaches that hold promise for treating conditions such as primary hydrocephalus (CH), which is characterized by increased cerebrospinal fluid (CSF) volumes and cerebral ventricular dilation as a result of impaired brain development, often due to genetic causes. CH is a significant contributor to childhood morbidity and mortality and a driver of healthcare costs. In many cases, prenatal ultrasound can readily identify ventriculomegaly as early as 14-20 weeks of gestation, with severe cases showing poor neurodevelopmental outcomes. Postnatal surgical approaches, such as ventriculoperitoneal shunts, do not address the underlying genetic causes, have high complication rates, and result in a marginal improvement of neurocognitive deficits. Prenatal somatic cell gene therapy (PSCGT) promises a novel approach to conditions such as CH by targeting genetic mutations in utero, potentially improving long-term outcomes. To better understand the pathophysiology, genetic basis, and molecular pathomechanisms of CH, we conducted a scoping review of the literature that identified over 160 published genes linked to CH. Mutations in L1CAM, TRIM71, MPDZ, and CCDC88C play a critical role in neural stem cell development, subventricular zone architecture, and the maintenance of the neural stem cell niche, driving the development of CH. Early prenatal interventions targeting these genes could curb the development of the expected CH phenotype, improve neurodevelopmental outcomes, and possibly limit the need for surgical approaches. However, further research is needed to establish robust genotype-phenotype correlations and develop safe and effective PSCGT strategies for CH.

Is choroid plexus growth altered in isolated ventriculomegaly on fetal neuro-ultrasound?

OBJECTIVES

Reveal developmental alterations in choroid plexus volume (CPV) among fetuses with isolated ventriculomegaly (VM) through neuro-ultrasound.

METHODS

This prospective study aimed to assess the development of fetal CPV in normal fetuses and those with isolated VM through neuro-ultrasound. The fetuses of isolated VM were categorized into mild, moderate, and severe groups, and subsequently, the lateral ventricle evolution was monitored. The developmental alterations in CPV among fetuses with isolated VM were determined by comparing the CPV z-scores with those of normal fetuses. Receiver operating characteristics curve analysis was used to assess the predictive value of altered CPV in lateral ventricle evolution.

RESULTS

A total of 218 normal fetuses and 114 isolated VM fetuses from 22 weeks to 35 weeks of gestation were included. The CPV decreased as the isolated VM was getting worse. Both fetuses with isolated moderate ventriculomegaly and those with isolated severe ventriculomegaly exhibited reduced CPV compared to normal fetuses. The CPV in fetuses with isolated mild ventriculomegaly (IMVM) varied, with some showing a larger CPV compared to normal fetuses, while others exhibited a smaller CPV. The larger CPV in cases of IMVM may serve as a predictive factor for either regression or stability of the lateral ventricle, while reduced CPV in cases of isolated VM may indicate worsening of the lateral ventricle.

CONCLUSION

The growth volume of fetal CP exhibited alterations in fetuses with isolated VM, and these changes were found to be correlated with the evolution of the lateral ventricle.

CLINICAL RELEVANCE STATEMENT

Neuro-ultrasound revealed varying degrees of alterations in the volume development of the choroid plexus within the fetus with isolated VM. The findings can help predict lateral ventricle prognosis, greatly contributing to prenatal diagnosis strategies for fetuses with isolated VM.

KEY POINTS

The volume of choroid plexus growth is altered in fetuses with isolated VM. The altered CPV in isolated VM was associated with lateral ventricle evolution. The findings are useful for prenatal counseling and managing fetuses with isolated VM.

Machine learning in prenatal MRI predicts postnatal ventricular abnormalities in fetuses with isolated ventriculomegaly

OBJECTIVES

To evaluate the intracranial structures and brain parenchyma radiomics surrounding the occipital horn of the lateral ventricle in normal fetuses (NFs) and fetuses with ventriculomegaly (FVs), as well as to predict postnatally enlarged lateral ventricle alterations in FVs.

METHODS

Between January 2014 and August 2023, 141 NFs and 101 FVs underwent 1.5 T balanced steady-state free precession (BSSFP), including 68 FVs with resolved lateral ventricles (FVM-resolved) and 33 FVs with stable lateral ventricles (FVM-stable). Demographic data and intracranial structures were analyzed. To predict the enlarged ventricle alterations of FVs postnatally, logistic regression models with 5-fold cross-validation were developed based on lateral ventricle morphology, blended-cortical or/and subcortical radiomics characteristics. Validation of the models' performance was conducted using the receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA).

RESULTS

Significant alterations in cerebral structures were observed between NFs and FVs (p < 0.05), excluding the maximum frontal horn diameter (FD). However, there was no notable distinction between the FVM-resolved and FVM-stable groups (all p > 0.05). Based on subcortical-radiomics on the aberrant sides of FVs, this approach exhibited high efficacy in distinguishing NFs from FVs in the training/validation set, yielding an impressive AUC of 1/0.992. With an AUC value of 0.822/0.743 in the training/validation set, the Subcortical-radiomics model demonstrated its ability to predict lateral ventricle alterations in FVs, which had the greatest predictive advantages indicated by DCA.

CONCLUSIONS

Microstructural alterations in subcortical parenchyma associated with ventriculomegaly can serve as predictive indicators for postnatal lateral ventricle variations in FVs.

CLINICAL RELEVANCE STATEMENT

It is critical to gain pertinent information from a solitary fetal MRI to anticipate postnatal lateral ventricle alterations in fetuses with ventriculomegaly. This approach holds the potential to diminish the necessity for recurrent prenatal ultrasound or MRI examinations.

KEY POINTS

Fetal ventriculomegaly is a dynamic condition that affects postnatal neurodevelopment. Machine learning and subcortical-radiomics can predict postnatal alterations in the lateral ventricle. Machine learning, applied to single-fetal MRI, might reduce required antenatal testing.