Hydrocephalus in Children: A Neuroradiological Perspective.

Concepts about the production, absorption, dynamics, and physiological roles of cerebrospinal fluid (CSF) have dramatically changed over the recent decades. This article will review these new concepts and detail how they must be used for a better assessment and a better understanding of the various aspects of hydrocephalus by using neuroradiological tools.

Magnetic Resonance Imaging Findings Are Associated with Long-Term Global Neurological Function or Death after Traumatic Brain Injury in Critically Ill Children.

The identification of children with traumatic brain injury (TBI) who are at risk of death or poor global neurological functional outcome remains a challenge. Magnetic resonance imaging (MRI) can detect several brain pathologies that are a result of TBI; however, the types and locations of pathology that are the most predictive remain to be determined. Forty-two critically ill children with TBI were recruited prospectively from pediatric intensive care units at five Canadian children's hospitals.

Deep venous communication in vein of Galen malformations: incidence, Imaging, and Implications for treatment.

Background: Failure to appreciate deep venous drainage pathways is a major cause of severe complications in the endovascular treatment of vein of Galen aneurysmal malformations (VOGMs).

Objective: To report deep venous drainage patterns in patients with VOGM, emphasizing the internal cerebral veins, and to describe the challenges in evaluating these.

Methods: Patients with VOGM presenting to our institute between 2000 and 2018 were retrospectively analyzed.

Corpus Callosum: Molecular Pathways in Mice and Human Dysgeneses.

The corpus callosum is the largest of the 3 telencephalic commissures in eutherian (placental) mammals. Although the anterior commissure, and the hippocampal commissure before being pushed dorsally by the expanding frontal lobes, cross through the lamina reuniens (upper part of the lamina terminalis), the callosal fibers need a transient interhemispheric cellular bridge to cross. This review describes the molecular pathways that initiate the specification of the cells comprising this bridge, the specification of the callosal neurons, and the repulsive and attractive guidance molecules that convey the callosal axons toward, across, and away from the midline to connect with their targets.

Neuroimaging in Pediatric Hydrocephalus.

The objective of this review is to discuss the role of neuroimaging in evaluating pediatric and fetal hydrocephalus based on possible pathophysiologic mechanisms and in the context of differing etiology. Although conventional brain imaging with ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) is commonly used to assess for ventricular enlargement, however, the underlying mechanisms and management of hydrocephalus is a challenge in pediatric population and fetal hydrocephalus. MRI helps define the possible nature of the obstruction, and provides useful functional and anatomic information.

Association of Severe Hydrocephalus With Congenital Zika Syndrome.

Importance: Hydrocephalus is a treatable but potentially fatal complication that has not been previously described in congenital Zika syndrome (CZS).

Objective: To describe the clinical features and imaging findings in 24 patients with congenital Zika syndrome (CZS) who developed hydrocephalus.

Design, Setting, And Participants: This case series included patients with hydrocephalus who were born in October and November 2015 and followed up until mid-2017 in the 2 largest national referral centers for CZS in Brazil.

Pediatric Brain Tumor Genetics: What Radiologists Need to Know.

Brain tumors are the most common solid tumors in the pediatric population. Pediatric neuro-oncology has changed tremendously during the past decade owing to ongoing genomic advances. The diagnosis, prognosis, and treatment of pediatric brain tumors are now highly reliant on the genetic profile and histopathologic features of the tumor rather than the histopathologic features alone, which previously were the reference standard.

Isolated neonatal bilateral vocal cord paralysis revealing a unilateral medullary defect: a case report.

Background: Congenital bilateral vocal cord paralysis is a rare occurrence. Approximately half the cases are associated with a major comorbidity, usually neurological, neuromuscular or malformative.

Case Presentation: In a male newborn, respiratory distress syndrome and stridor were observed immediately following birth.

Chiari 1 deformity in children: etiopathogenesis and radiologic diagnosis.

The metamerically associated normal hindbrain and normal posterior fossa are programmed to grow together in such a way that the tonsils are located above the foramen magnum and surrounded by the cerebrospinal fluid (CSF) of the cisterna magna. This allows the pulsating CSF to move freely up and down across the craniovertebral junction (CVJ). A developmental mismatch between the rates of growth of the neural tissue and of the bony posterior fossa may result in the cerebellar tonsils being dislocated across the foramen magnum.

Differential patterns of metastatic dissemination across medulloblastoma subgroups.

OBJECTIVE Metastatic dissemination is a major treatment challenge and cause of death in patients with medulloblastoma. However, the influence of molecular biology on the pattern of metastatic dissemination at diagnosis is not known. In this study, the authors sought to define the location, pattern, and imaging characteristics of medulloblastoma metastases across subgroups at diagnosis.

Intracranial artery to artery spontaneous revascularization in a child.

Introduction: Intracranial artery-to-artery antegrade revascularization is a poorly recognized entity, more so when it involves main stem arteries. The etiology, appearance, and significance of this condition are not described in the literature.

Case Presentation: We describe a case of spontaneous revascularization of a chronically occluded middle cerebral arterial branch by collaterals from the proximal segment reconstituting distal flow, mimicking a brain arteriovenous malformation in a 9-year old boy.

Cerebral hemispheric low-grade glial tumors in children: preoperative anatomic assessment with MRI and DTI.

Purpose: The aims of this study are to analyze how the nature and the behavior of low-grade glial tumors (LGGT) in children may correlate with the anatomy of the cerebral hemispheres and to evaluate the consequent impact of diffusion tensor imaging (DTI) techniques in the presurgical assessment.

Methods: This is a combined review of a series of 155 cases of LGGT and of the recent literature on the subject.

Results: The cases retrieved from our data bank were divided in central hemispheric tumors (basal ganglia and thalami) (36 cases), glioneuronal cortical-based tumors (49 cases), and glial tumors of the cerebral mantle (70 cases).

Longitudinal Study of White Matter Development and Outcomes in Children Born Very Preterm.

Identifying trajectories of early white matter development is important for understanding atypical brain development and impaired functional outcomes in children born very preterm (<32 weeks gestational age [GA]). In this study, 161 diffusion images were acquired in children born very preterm (median GA: 29 weeks) shortly following birth (75), term-equivalent (39), 2 years (18), and 4 years of age (29). Diffusion tensors were computed to obtain measures of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), which were aligned and averaged.

Chiari Type 1 Deformity in Children: Pathogenetic, Clinical, Neuroimaging, and Management Aspects.

Our understanding of cerebellar tonsillar herniation evolved over time and nowadays various pathomechanisms have been proposed. Causes of tonsillar herniation share a discrepancy between content (fore- and hindbrain) and container (supratentorial cranial vault, posterior fossa), may be associated with abnormalities of the craniocervical junction, and may have a developmental or acquired nature. In tonsillar herniation, the hindbrain is not malformed but deformed.

Diffusion tensor imaging-based assessment of white matter tracts and visual-motor outcomes in very preterm neonates.

Introduction: The purpose of this study was to assess the impact of brain injury on white matter development and long-term outcomes in very preterm (VPT) neonates.

Methods: Eighty-five VPT neonates (born <32/40 weeks gestational age (GA)) scanned within 2 weeks of birth were divided into three groups based on the presence of perinatal cerebral injury: (i) no injury, (ii) mild/moderate injury and (iii) severe injury. Diffusion tensor imaging (DTI) was acquired for each neonate and fractional anisotropy (FA), and diffusivity measures were calculated in the posterior limb of the internal capsule (PLIC) and optic radiation (OR).

Corpus callosum abnormalities: neuroradiological and clinical correlations.

Aim: To study neuroradiological features in pediatric patients with corpus callosum abnormalities, using new functional subtyping for the corpus callosum, and to correlate the features with the clinical presentation.

Method: We performed a retrospective review of 125 patients with radiologically identified abnormalities of the corpus callosum seen between 1999 and 2012. The study reviewed clinical features, genetic etiology, and chromosomal microarray (CMA) results.

Longitudinal cerebellar growth following very preterm birth.

Purpose: To measure cerebellar growth in a longitudinal cohort of very preterm infants to identify early predictors of subsequent brain growth. Although the cerebellum grows rapidly during late gestation, the rate and variability of growth following premature birth, and the effects of associated injury, are largely unknown.

Materials And Methods: In all, 105 very-preterm born infants (24-32 weeks GA) were imaged using magnetic resonance imaging (MRI) at birth, term-equivalent, 2, and 4 years of age.

Posterior fossa tumors in children: developmental anatomy and diagnostic imaging.

Introduction: Modern understanding of the relation between the mutated cancer stem cell and its site of origin and of its interaction with the tissue environment is enhancing the importance of developmental anatomy in the diagnostic assessment of posterior fossa tumors in children. The aim of this review is to show how MR imaging can improve on the exact identification of the tumors in the brainstem and in the vicinity of the fourth ventricle in children, using both structural imaging data and a precise topographical assessment guided by the developmental anatomy.

Results: The development of the hindbrain results from complex processes of brainstem segmentation, ventro-dorsal patterning, multiple germinative zones, and diverse migration pathways of the neural progenitors.

MR assessment of pediatric hydrocephalus: a road map.

Purpose: This study was conducted to design a rational approach to the MR diagnosis of hydrocephalus based on a pathophysiologic reevaluation of its possible mechanisms and to apply it to the different etiological contexts.

Method: A review of the literature reports describing new physiologic models of production and absorption and of the hydrodynamics of the CSF was made.

Results: Besides the secretion of CSF by the choroid plexuses, and its passive, pressure-dependent transdural absorption (arachnoid villi, dural clefts, cranial, and spinal nerve sheaths), water transporters, aquaporins, allow water (if not ions and organic molecules) to exchange freely between the brain parenchyma and the CSF spaces across the ependymal and the pial interfaces (including the Virchow-Robin spaces).

Cerebral maturation in the early preterm period-A magnetization transfer and diffusion tensor imaging study using voxel-based analysis.

The magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI) correlates of early brain development were examined in cohort of 18 very preterm neonates (27-31 gestational weeks) presenting with normal radiological findings scanned within 2weeks after birth (28-32 gestational weeks). A combination of non-linear image registration, tissue segmentation, and voxel-wise regression was used to map the age dependent changes in MTR and DTI-derived parameters in 3D across the brain based on the cross-sectional in vivo preterm data. The regression coefficient maps obtained differed between brain regions and between the different quantitative MRI indices.

Congenital absence of the mammillary bodies: a novel finding in a well-studied case of developmental amnesia.

Individuals with developmental amnesia experience compromised development of episodic memory for details of personal life events, believed to relate to changes to the hippocampus after birth. Here we report the very rare discovery of aplasia of the mammillary bodies, hypogenesis of the fornix, and abnormal hippocampal shape and orientation in H.C.

Brain vein disorders in newborn infants.

The brain veins of infants are in a complex phase of remodelling in the perinatal period. Magnetic resonance venography and susceptibility-weighted imaging, together with high-resolution Doppler ultrasound, have provided new tools to aid study of venous developmental anatomy and disease. This review aims to provide a comprehensive background of vein development and perinatal venous lesions in preterm and term-born infants, and to encourage further research in both the fetus and the newborn infant, with the aim of preventing or mitigating parenchymal injury related to diseases involving veins.

A mechanical model predicts morphological abnormalities in the developing human brain.

The developing human brain remains one of the few unsolved mysteries of science. Advancements in developmental biology, neuroscience, and medical imaging have brought us closer than ever to understand brain development in health and disease. However, the precise role of mechanics throughout this process remains underestimated and poorly understood.

Duration of the pre-diagnostic interval in medulloblastoma is subgroup dependent.

Background: Children presenting with medulloblastoma have a wide range of initial presenting symptoms. However, the influence of underlying tumor biology on the initial presentation of medulloblastoma is currently unknown. In light of the recent discovery of distinct medulloblastoma subgroups, we sought to define the initial presentation of childhood medulloblastoma in a subgroup specific manner.