Ob-Gyn Fetal Neural Axis (wkbk)

a ventricle is considered dilated when its diameter exceeds _____

10mm

Semilobar holoprosencephaly

A single ventricular cavity with partial formation of the occipital horns, partial or complete fusion of the thalamus, a rudimentary falx and interhemispheric fissure , and a absent corpus callosum, Cavum septum Pellucidum, and olfactory bulbs.

Fetuses with *myelomeningoceles* often present with cranial defects associated with ____. which is 90% of patients

Chiari type 2

Alobar holoprosencephaly

a monoventricle brain tissue that is small and may have a cup, ball, or pancake configuration fusion of thalamus absence of the interhemispheric fissure. cavum speti pellucidi, corpus callosum, optic tracts, and olfactory bulbs

ventriculomegaly

abnormal accumulation of cerebrospinal fluid within the cerebral ventricles-dilation of the ventricles; compression of the developing brain tissue and brain damage may result; commonly associated with additional fetal anomalies

Sonographic features of anencephaly

absence of the brain and cranial vault rudimentary brain tissue characterized as the cerebrovasculosa budging fetal orbits (frog like appearance)

sonographic features of agenesis of the corpus callosum

absence of the corpus callosum elevation and dilation of the third ventricle widely separated lateral ventricle frontal bones with medial indentation of the medial walls dilated occipital borns giving lateral ventricles a teardrop shape absnce of the cavum septi pellucidi

________ _______ results from obstruction, atresia, or stenosis of the aqueduct of sylvius, causing ventriculomegaly

aqueductal stenosis

a neural tube defect in which the meninges and brain herniate through a defect in the calvarium

cephalocele

spina bifida occulta

closed defect of the spine without protrusion of meninges or spinal cord

cyclopia

common ventricle, fusion of orbits with one or 2 eyes present, and a proboscis severe form of holoprosencephaly

acrania

complete or partial absence of the cranial bones assoc. with anencephaly

a fibrous tract that connects the cerebral hemispheres and aids in learning and memory

corpus callosum

macrocephaly

enlargement of the fetal cranium as a result of ventriculomegaly

anencephaly

failure of closure of the neural tube at cranial end

Cephalic neural plate develops into ______, and the caudal end forms the ______.

forebrain spinal cord

Cebocephaly

form of holoprosencephaly characterized by a common ventricle, hypotelorism, and a nose with a single nostril

cranial meningocele

herniation of only meninges

encephalocele

herniation of the meninges and brain through defect

cystic hygroma

increase in size of the jugular lymphatic sacs caused by abnormal development

almost complete division of the venticles is seen with a corpus callosum that may be normal, hypoplastic, or absent, although the cavum septi pellucidi will still be absent in _______

lobar holoprosencephaly

Alobar holoprosencephaly

most severe form of holoprosencephaly characterized by a single common ventricle and a malformed brain

anencephaly

neural tube defect characterized by lack of development of the cerebral and cerebellar hemispheres and cranial vault; ****incompatible with life

spina bifida

neural tube defect of the spine- dorsal vertebrae fail to fuse, allowing protrusion of meninges and or spinal cord through the defect

enlargement of the venticles occurs with _________ of cerebrospinal fluid flow

obstruction

fetal ventriculomegaly typically progresses from the ______ _____ into the temporal and then to the ________ ventricular horns

occipital frontal

meningomyelocele

open spinal defect- protrusion of meninges and spinal cord through defect, usually within a meningeal sac

meningocele

open spinal defect- protrusion of the spinal meninges

_______ or ______ cysts are cysts filled with cerebrospinal fluid

porencephaly or porencephalic cysts

sonographic features of Dandy Walker Malformation

post fossa cyst that can very considerably in size splaying of the cerebellar hemispheres as a result of complete/ partial agenesis of the cerebellar vermis an enlarged cisterna magna ventriculomegaly

Sonographic features of acrania

presence of brain tissue without the presence of a calvarium disorganization of the brain tissue prominent sulcal markings

The forebrain will develop into the _____, midbrain will become the _____, and the hindbrain will form the ________.

prosencephalon mesencephalon rhombencephalon

Holoprosencephaly

range of abnormalities resulting from abnormal cleavage of the forebrain

a rare disorder characterized by clefts in the cerebral cortex

schizencephaly

sonographic features of spina bifida

splaying of the post. ossification centers with a V or U configuration protrusion of a sac like structure that may be anechoic(meningocele) or contain neural elements(myelomeningocele) a cleft in the skin ventriculomegaly

hydrocephalus

ventriculomegaly in neonate abnormal accumulation of cerebrospinal fluid within the cerebral ventricles resulting in compression and frequently destruction of brain tissue