title: Transitional forms of Arnold-Chiari and Dandy-Walker malformations.
abstract: The morphological findings in 12 cases of Arnold-Chiari and 3 cases of Dandy-Walker malformations are described and compared to those in 2 cases of congenital hydrocephalus of unknown origin, 1 case of isolated meningo-myelocele and 2 cases of normal newborn brains. Lesions common to both types of malformation indicate a same time-related embryogenetic defect of the roofplate of the rhombencephalon, that does not allow the inferior vermis and the choroid plexus to turn inward into the fourth ventricle.
mesh_terms: D001139:Arnold-Chiari Malformation / Q000196:embryology / Q000473:pathology*; D001921:Brain / Q000196:embryology / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology; D002531:Cerebellum / Q000473:pathology; D002831:Choroid Plexus / Q000473:pathology; D003616:Dandy-Walker Syndrome / Q000196:embryology / Q000473:pathology*; D006801:Humans; D006849:Hydrocephalus / Q000473:pathology*; D007223:Infant; D007231:Infant, Newborn; D008591:Meningomyelocele / Q000473:pathology