Hydranencephaly: a rare cause of an enlarging head size in an infant

MR insights into fetal brain development: what is normal and what is not

Fetal brain development is a complex, rapid, and multi-dimensional process that can be documented with MRI. In the second and third trimesters, there are predictable developmental changes that must be recognized and differentiated from disease. This review delves into the key biological processes that drive fetal brain development, highlights normal developmental anatomy, and provides a framework to identify pathology. We will summarize the development of the cerebral hemispheres, sulci and gyri, extra-axial and ventricular cerebrospinal fluid, and corpus callosum and illustrate the most common abnormal findings in the clinical setting.

Ultrasonographic approach and findings in calves with hydranencephaly

BACKGROUND

Teratogenic viral infections may proceed to hydranencephaly in cattle. Post-mortem and antemortem diagnosis can be achieved by necropsy or ultrasonography, CT-scan and MRI techniques.

OBJECTIVES

The aim of this study was to determine how effective ultrasonography approach is in detecting hydranencephaly in calves.

METHODS

In this study, ultrasonography images were obtained from brains of nine Holstein claves, of the same age, with neurological signs (due to Akabane virus infection), approaching from the caudal part of the temporal bone. To confirm the obtained images, the same approach was used to obtain images from a normal calf of the same age. The thickness of the temporal bone was measured and compared in seven affected and the healthy calves, using CT-scan images.

RESULTS

In ultrasonographic images, temporal bone (as a hyperechoic structure) and temporal cortical mantle (as an echogenic structure) were noted in the right and left side of the skull. The medial part of the image showed presence of fluid in an anechoic region, instead of brain parenchyma. Falx cerebri was also seen as a floating hyperechoic line in the middle part in all patients. There was no statistically significant difference between the thickness of temporal bone in normal and affected calves (p = 0.502). All findings were confirmed by necropsy.

CONCLUSIONS

Transtemporal approach is a novel and easy approach to study the brain in calves. This is the first study on the hydranencephalic brains of claves, using ultrasonography by transtemporal approach.

Not all ventriculomegaly is created equal: diagnostic overview of fetal, neonatal and pediatric ventriculomegaly

Fetal ventriculomegaly refers to a condition in which there is enlargement of the ventricular spaces, typically on prenatal ultrasound. It can be associated with other CNS or extra-CNS abnormalities, and this relationship is crucial to understand as it affects overall neonatal outcome. Isolated ventriculomegaly has been described in the literature with variable clinical outcome. Typically, outcome is based on the etiology and degree of ventriculomegaly. When associated with a pathologic condition, ventriculomegaly can be a result of hydrocephalus. While initial diagnosis is usually made on prenatal ultrasound, fetal magnetic resonance imaging is preferred to further elucidate any associated CNS malformations. In this paper, the authors aim to provide a comprehensive review of the diagnosis, associated etiologies, prognosis, and treatment options related to fetal, neonatal, and pediatric ventriculomegaly and hydrocephalus. In addition, preliminary data is provided from our institutional cohort of patients with a prenatal diagnosis of ventriculomegaly followed through the perinatal period.