Regional brain development in fetuses with Dandy-Walker malformation: A volumetric fetal brain magnetic resonance imaging study.

Shizuko Akiyama,Kiho Im,Alexa Craig,Hyuk Jin Yun,George Graham,Atsushi Hozawa,Neel Madan,Tomohiro Nakamura,Rie Kitano,Tomo Tarui,Ellen Grant,Osamu Samura

doi:10.1371/journal.pone.0263535

Abstract

Dandy-Walker malformation (DWM) is a common prenatally diagnosed cerebellar malformation, characterized by cystic dilatation of the fourth ventricle, upward rotation of the hypoplastic vermis, and posterior fossa enlargement with torcular elevation. DWM is associated with a broad spectrum of neurodevelopmental abnormalities such as cognitive, motor, and behavioral impairments, which cannot be explained solely by cerebellar malformations. Notably, the pathogenesis of these symptoms remains poorly understood. This study investigated whether fetal structural developmental abnormalities in DWM extended beyond the posterior fossa to the cerebrum even in fetuses without apparent cerebral anomalies. Post-acquisition volumetric fetal magnetic resonance imaging (MRI) analysis was performed in 12 fetuses with DWM and 14 control fetuses. Growth trajectories of the volumes of the cortical plate, subcortical parenchyma, cerebellar hemispheres, and vermis between 18 and 33 weeks of gestation were compared. The median (interquartile range) gestational ages at the time of MRI were 22.4 (19.4–24.0) and 23.9 (20.6–29.2) weeks in the DWM and control groups, respectively (p = 0.269). Eight of the 12 fetuses with DWM presented with associated cerebral anomalies, including hydrocephalus (n = 3), cerebral ventriculomegaly (n = 3), and complete (n = 2) and partial (n = 2) agenesis of the corpus callosum (ACC); 7 presented with extracerebral abnormalities. Chromosomal abnormalities were detected by microarray analysis in 4 of 11 fetuses with DWM, using amniocentesis. Volumetric analysis revealed that the cortical plate was significantly larger in fetuses with DWM than in controls (p = 0.040). Even without ACC, the subcortical parenchyma, whole cerebrum, cerebellar hemispheres, and whole brain were significantly larger in fetuses with DWM (n = 8) than in controls (p = 0.004, 0.025, 0.033, and 0.026, respectively). In conclusion, volumetric fetal MRI analysis demonstrated that the development of DWM extends throughout the brain during the fetal period, even without apparent cerebral anomalies.

Highlights

Dandy-Walker malformation (DWM) is a well-known congenital anomaly of the cerebellum and posterior fossa
Volumetric analysis of fetal magnetic resonance imaging (MRI) revealed that regardless of heterogeneous etiologies, fetuses with DWM had a larger cortical plate volume compared to control fetuses
These results suggest that even without apparent cerebral abnormalities, fetuses with DWM have altered development that extends throughout the brain, and these subtle alterations in brain development can be detected using quantitative fetal MRI analysis

Summary

Introduction

Dandy-Walker malformation (DWM) is a well-known congenital anomaly of the cerebellum and posterior fossa. DWM is diagnosed based on several characteristic imaging features, including cystic dilatation of the fourth ventricle, upward rotation of the hypoplastic vermis, and enlargement of the posterior fossa with elevated torcular herophili and tentorium [2–4]. A hypoplastic vermis and fourth ventricular cyst constitute core structural abnormalities in DWM, coexisting cerebral abnormalities are presenting features in up to 67% of cases [5,10]. These include agenesis of the corpus callosum (ACC), gray matter heterotopia, and cerebral gyral anomalies [5,11–13]. Fetuses with DWM may share the feature of diffuse cerebral pathology, which is a common cause of cerebral functional impairments such as cognitive, motor, and behavioral neurodevelopmental abnormalities.

Results

Discussion

Conclusion