DMS 221 Penny Chapter 24

Fetal Head and Brain

most severe form of holoprosencephaly

alobar holoprosencephaly

genetic disorder that includes craniosynostosis, midline facial hypoplasia, and syndactyly

apert syndrome

abnormal narrowing of the cerebral aqueduct

aqueduct stenosis

benign cysts within the brain that do not communicate with the ventricular system

arachnoid cysts

a group of cranial abnormalities associated with spina bifida

arnold chiari II malformation

a growth disorder syndrome associated with enlargement of several organs, including the skull, tongue, and liver

beckwith-wiedemann syndrome

close-set eyes (hypotelorism) and a nose with a single nostril

cebocephaly

the portion of the cerebellum, located within the midline of the brain, that connects its two hemispheres

cerebellar vermis

a prominent space within the skull that contains cerebrospinal fluid; a ____ is created by the separation of the arachnoid membrane and pia mater

cicstern

the abnormal lateral ventricle shape in which there is a small frontal horn and enlarged occipital horn

colpocephaly

the obstruction of cerebrospinal fluid from a source outside the ventricular system

communicating hydrocephalus

a spectrum of posterior fossa abnormalities that involves the cystic diatalation of the cisterna magna and fourth ventricle

dandy-walker complex

congenital brain malformation in which there is enlargement of the cisterna magna, agenesis of the cerebellar vermis, and dilation of the fourth ventricle

dandy-walker malformation

the dense, fibrous outer layer of the meninges

dura mater

a form of acrania in which the entire cerebrum is located outside the skull

exencephaly

the opening in the base of the skull through which the spinal cord exists

foramen magnum

a group of thin-walled blood vessels and cells within the subependymal layer of the fetal brain responsible for brain cell migration during fetal development

germinal matrix

fold in the cerebral cortex

gyri

a group of brain abnormalities consisting of varying degrees of fusion of the lateral ventricles, absence of the midline structures, and associated facial anomalies

holoprosencephaly

a fatal condition in which the entire cerebrum is replaced by a large sac containing cerebrospinal fluid

hydranencephaly

the dilatation of the ventricular system caused by an increased volume of cerebrospinal fluid, resulting in increased intraventricular pressure

hydrocephalus

“smooth brain”; condition where there is little to no gyri or sulci within the cerebral cortex

lissencephaly

the least severe form of holoprosencephaly

lobar holoprosencephaly

a fetal syndrome associated with microcephaly, occipital encephalocele, polydactyly, and polycystic kidneys

meckel-gruber syndrome

herniation of the cranial or spinal meninges because of an open cranial or a spinal defect

meningocele

mass that results from spina bifida that contains the spinal cord and the meninges

myelomeningocele

a chromosomal aberration in which there is a third chromosome 13; also referred to as trisomy 13

patau syndrome

a condition in which a cyst, most often caused by an intraparenchymal hemorrhage, communicates with a lateral ventricle

porencephaly

an elongated, narrow head shape, may also be referred to as dolichocephaly

scaphocephaly

a cerebral malformation associated with the development of fluid-filled clefts

schizencephaly