Neuroimaging clinics of North America
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This article discusses the normal anatomy of the posterior fossa structures followed by a discussion of the characteristic neuroimaging features of a variety of cerebellar and brainstem malformations. In this context, the authors classify posterior fossa malformations based on the neuroimaging pattern into (1) predominantly cerebellar, (2) cerebellar and brainstem, and (3) predominantly brainstem malformations.
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Neuroimaging Clin. N. Am. · Aug 2019
ReviewThe Distal Spine: Normal Embryogenesis and Derangements Leading to Malformation.
The spine and spinal cord are composed of multiple segments initiated by different embryologic mechanisms and advanced under different systems of control. In humans, the upper central nervous system is formed by primary neurulation, the lower by secondary neurulation, and the intervening segment by junctional neurulation. This article focuses on the distal spine and spinal cord to address their embryogenesis and the molecular derangements that lead to some distal spinal malformations.
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Neuroimaging Clin. N. Am. · Aug 2019
ReviewDisorders of Ventral Induction/Spectrum of Holoprosencephaly.
Disorders of the ventral induction give rise to a group of congenital malformations that share in common the failure of the prosencephalon cleavage and subsequent formation of midline structures, presenting with a wide spectrum of severity. This article focuses on the imaging findings of the holoprosencephaly spectrum and septo-optic dysplasia, their epidemiology, embryology, and the common clinical associated anomalies. Knowledge of the imaging features of these disorders is necessary for a correct interpretation of findings and accurate parental counseling. Diagnostic evaluation of patients should include molecular screening and genetic counseling to characterize prognosis and risk of recurrence.
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Neuroimaging Clin. N. Am. · Aug 2019
ReviewConnectomics in Brain Malformations: How Is the Malformed Brain Wired?
A new neuroimaging dimension is currently being adopted. The structural connectome reveals macroscale white matter connectivity of the human brain, providing insights into brain networks organization. ⋯ Connectomics provides a powerful set of network measures, which can serve as noninvasive biomarkers for the diagnosis, prognostication, and treatment response of children. We discuss the principles of connectome reconstruction and visualization of the pediatric structural connectome using current state-of-the-art neuroimaging and postprocessing techniques, and we describe potential connectomics applications to study brain malformations.
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Neuroimaging Clin. N. Am. · Aug 2019
ReviewCorpus 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.