title: Pre- and Postnatal Neuroimaging of Congenital Cerebellar Abnormalities.
abstract: The human cerebellum has a protracted development that makes it vulnerable to a broad spectrum of developmental disorders including malformations and disruptions. Starting from 19 to 20 weeks of gestation, prenatal magnetic resonance imaging (MRI) can reliably study the developing cerebellum. Pre- and postnatal neuroimaging plays a key role in the diagnostic work-up of congenital cerebellar abnormalities. Diagnostic criteria for cerebellar malformations and disruptions are based mostly on neuroimaging findings. The diagnosis of a Dandy-Walker malformation is based on the presence of hypoplasia, elevation, and counterclockwise upward rotation of the cerebellar vermis and cystic dilatation of the fourth ventricle, which extends posteriorly filling out the posterior fossa. For the diagnosis of Joubert syndrome, the presence of the molar tooth sign (thickened, elongated, and horizontally orientated superior cerebellar peduncles and an abnormally deep interpeduncular fossa) is needed. The diagnostic criteria of rhombencephalosynapsis include a complete or partial absence of the cerebellar vermis and continuity of the cerebellar hemispheres across the midline. Unilateral cerebellar hypoplasia is defined by the complete aplasia or hypoplasia of one cerebellar hemisphere. Familiarity with these diagnostic criteria as well as the broad spectrum of additional neuroimaging findings is important for a correct pre- and postnatal diagnosis. A correct diagnosis is essential for management, prognosis, and counseling of the affected children and their family.
authors.affiliation: Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Zayed Building Room 4174, 1800 Orleans Street, Baltimore, MD, 21287, USA. aporett1@jhmi.edu.|Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland. aporett1@jhmi.edu.
authors.forename: Andrea
authors.initials: A
authors.lastname: Poretti
authors.affiliation: Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland.
authors.forename: Eugen
authors.initials: E
authors.lastname: Boltshauser
authors.affiliation: Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Zayed Building Room 4174, 1800 Orleans Street, Baltimore, MD, 21287, USA.
authors.forename: Thierry A G M
authors.initials: TAGM
authors.lastname: Huisman
mesh_terms: D001921:Brain / Q000473:pathology*; D002526:Cerebellar Diseases / Q000473:pathology*; D002658:Developmental Disabilities / Q000473:pathology*; D006801:Humans; D009421:Nervous System Malformations / Q000473:pathology*; D059906:Neuroimaging / Q000379:methods; D013569:Synapses / Q000473:pathology*
keywords: Cerebellum; Fetal; Malformations; Neuroimaging