OB: Fetal Neural Axis

Acrania

A condition in which a complete or partial absence of the cranial bones is demonstrated is which one of the following?

Cebocephaly

A form of holoprosencephaly characterized by a common ventricle, hypotelorism, and a nose with a single nostril is which one of the following?

-An aneurysm of the Galen vein -A rare arteriovenous malformation -A sporadic event

A vein of Galen malformation is which one of the following abnormalities?

Meningomyelocele

An open spinal defect characterized by a protrusion of meninges and spinal cord through the defect, usually within a meningeal sac, is called which one of the following?

Holoprosencephaly

Anomalies associated with anencephaly include all of the following except:

Choroid plexus cyst

Conditions commonly associated with fetal hydrocephalus include all of the following except:

Arachnoid cyst

Differential considerations of Dandy-Walker malformation should include which one of the following?

Hypertelorism

Facial anomalies in holoprosencephaly may represent all of the following except:

Agenesis of the corpus callosum

The absence of the cavum septi pellucidi is a distinguishing characteristic of which one of the following fetal anomalies?

Arachnoid cyst

The differential considerations of anencephaly include all of the following except:

Hydrocephalus

Ventriculomegaly coupled with an enlargement of the fetal head is called which one of the following?

10

Ventriculomegaly is defined as lateral ventricular enlargement measuring greater than ____ millimeters (mm).

Hydranencephaly

Which one of the following abnormalities is described as the congenital absence of the cerebral hemispheres resulting from an occlusion of the carotid arteries. The midbrain structures are present, and fluid replaces cerebral tissue.

Anencephaly

Which one of the following abnormalities is the most common open neural tube defect?

Dandy-Walker malformation

Which one of the following anomalies is characterized by the presence of a posterior fossa cyst and a splaying of the cerebellar hemispheres?

Agnesis of the corpus callosum

Which one of the following anomalies may be characterized by the presence of colpocephaly?

Dandy-Walker malformation

Which one of the following central nervous anomalies demonstrates splaying of the cerebellar hemispheres on ultrasound?

Encephalocele

Which one of the following defects is associated with Meckel-Gruber syndrome?

Holoprosencephaly

Which one of the following fetal head anomalies is characterized by the presence of a single primitive ventricle?

Alobar

Which one of the following is the most severe form of holoprosencephaly, which is characterized by a single common ventricle and malformed brain? Orbital anomalies range from fused orbits to hypotelorism, with frequent nasal anomalies and clefting of the lip and palate.

Anencephaly

Which one of the following neural tube defects is characterized by lack of development of the cerebral and cerebellar hemispheres and cranial vault and is an abnormality that is incompatible with life?

Banana- and lemon-shaped

Which one of the following signs are characteristic of the Arnold-Chiari malformation?

Anencephaly has a male prevalence

Which one of the following statements about anencephaly is incorrect?

Microcephaly is an abnormally large head

Which one of the following statements about microcephaly is incorrect?

Encephalocele

Which one of the following terms is used to describe the herniation of the meninges and brain through a calvarium defect?