Fetal Head Abnormalites numero dos

Question 1

What is Holoprosencephaly?

Answer 1

failure of division of the prosencephalon (fore brain) resulting in varying degree of prosencephalon midline defects

Question 2

What is the clinical presentation of holoprosencephaly?

Answer 2

proboscis
cyclopia
cleft lip/palate
occular hypotelorism
colitary median maxillary central incisor

Question 3

What chromosomal abnormalities are associated with holoprosencephaly (aneuploidic)

Answer 3

Tri13 (most common)

Tri18

Question 4

What is associated with holoprosencephaly (non-aneuploidic)

Answer 4

congenital renal anomalies
congenital cardiac anomalies
diabetic embryopathy
facial anomalies
shprintzen syndrome

Question 5

What are the 3 subtypes of holoprosencephaly

Answer 5

alobar
semilobar
lobar

Question 6

What is alobar holoprosencephaly

Answer 6

thalami are fused
single posterior ventricle
a/w: facial abnormalities– cyclopia, ethmocephaly, cebocephaly and median cleft lip

Question 7

What is semi lobar holoprosencephaly

Answer 7

central lobes are present: most commonly fused anteriorly and at the thalami
olfactory tracts/bulbs are not present
agenesis/hypoplasia of CC

Question 8

What is lobar holoprosencephaly

Answer 8

least affected
more subtle midline abnormalities: fusion of cingulate gyrus and thalami
olfactory tracts/CC can be absent or hypoplastic

Question 9

Is holoprosencephaly compatible with extra uterine life?

Answer 9

not usually

depends on type

Question 10

What is the most common type of holoprosencephaly

Answer 10

Alobar

Question 11

There’s a lotta shit on holoprosencephaly so

Answer 11

review the slides

Question 12

What is hydranencephaly

Answer 12

gross ventriculomegaly due to complete or near complete absence of cerebral tissue

Question 13

What does hydranencephaly appear as?

Answer 13

absence of the cerebral hemispheres with an incomplete or absence falx and a sac-like structure cerebral fluid surrounding the brainstem and basal ganglia

Question 14

What is the key sonographic feature of hydranencephaly?

Answer 14

large cranial fluid collection lacking a mantle or rim of cerebral brain tissue

Question 15

Is hydranencephaly compatible with life?

Answer 15

no

Question 16

What is schizencephaly?

Answer 16

clefts in the cerebral mantle (usually bilateral), lined by pia-ependyma, with communication between the ventricles and subarachnoid space

Question 17

How is Dandy Walker Malformation characterized

Answer 17

complete agenesis of cerebellar vermis

Question 18

What is a primary (congenital) arachnoid cyst

Answer 18

results from benign accumulation of clear fluid between the dura and the brain substance throughout the CNS
related to the arachnoid membrane and does not communicate with the subarachnoid space.

Question 19

What is secondary (acquired) arachnoid cysts

Answer 19

result from haemorrhage, trauma, and infection

usually communicate with the subarachnoid space

Question 20

Does an arachnoid cyst communicate with the ventricles?

Answer 20

No

Question 21

What is porencephaly (porencephalic cyst)?

Answer 21

rare disorder
no mass effect
cystic degeneration & encephalomalacia and the formation of porencephalic cysts

Question 22

Porencephaly is more severe than hydranencephaly. True or false

Answer 22

False– less severe

Question 23

What causes porencephaly

Answer 23

infarction or hemorrhage into brain parenchyma due to insult in utero (abruption, trauma, infection) causing focal or widespread ischemia

necrosis and cystic resolution of brain tissue leads to cyst formation that communicates with the ventricle.

Question 24

Do porencephalic cysts communicate with the ventricular system and subarachnoid space?

Answer 24

yes

Question 25

What is Arnold Chiari malformation?

Answer 25

prolapse of hindbrain structures below the foramen magnum

a/w: skeletal abnormalities and neurological dysfunction

Question 26

What is type 1 of Arnold Chiari?

Answer 26

just a lip of cerebellum is downwardly displaced with the tonsils, but the fourth ventricle remains in the posterior fossa this is mainly an incidental CT discovery

Question 27

What is type 2 of Arnold Chiari?

Answer 27

usually involved in prenatal cases and is a congenital deformity characterized by displacement of cerebellar tonsils, parts of the cerebellum, fourth ventricle, pons, and medulla oblongata through the foramen magnum into the spinal canal
usually accompanied by hydrocephalus and myelomeningocele.

Question 28

What is type 3 of Arnold Chiari?

Answer 28

more severe form, with large herniation of the posterior fossa content and myelomeningocele and hydrocephalus

Question 29

Which type of Arnold Chiari do we see schematic changes?

Answer 29

Type 2

Question 30

What is a sign we see in Arnold Chiari Malformation?

Answer 30

Bananaaaaa sign – lobes of cerebellum lost their lumpy appearance and vermian incisure aint normal