Fetal Brian Abnormalities Flashcards
the neural tube should close by ___ weeks
6
neural tube defects usually have an increase in ____
MSAFP
there is an increase risk of NTD with what factors
- maternal obesity
- poorly controlled maternal diabetes
- certain anti seizure meds
what are examples of open NTD
- anencephaly
- myelomeningocele
- cranioarchischisis
what are examples of closed NTD
- spina bifida
- occulta
- spinal cord tethering
___: meninges with or without brain or spinal cord tissue herniates through an opening in the skull or vertebral column
herniation NTD
___: buildup of fluid inside the skull leading to brain swelling
hydrocephalus
what is the cause of hydrocephalus
abnormal CSF drainage or the brain is producing too much CSF
what is the first sign of hydrocephalus
dilation of lateral ventricles
hydrocephalus is related to what other conditions
- aqueductal stenosis
- chiari malformation
- dandy walker malformation
- trisomies
if hydrocephalus is caused by aqueduct stenosis then which part of the brain is normal in size
4th ventricle
what is the common sign associated with hydrocephalus
dangling choroid sign or teardrop ventricles
how is hydrocephalus treated
intraventricular shunt from the fetal brain to the peritoneal cavity
___: dilation if the the lateral ventricles only
ventriculomegaky
what is the ventricle mmt for mild ventriculomegaly
10-15mm
what is the ventricle mmt for moderate ventriculomegaly
16-20mm
what is the ventricle mmt for severe ventriculomegaly
20mm
what are some possible causes of ventriculomegaly
- brain destruction
- maldevelopment
- holoprosencephaly
- hydranencephaly
ventriculomegaly has been associated with what other things
- polyhydramnios
- myelomeningocele
- encephalocele
- dandy walker malfrormatio
what two signs are associated with chiari malformation
banana sign and melon sign
___: displacement of the brain structures of the posterior fossa through the foramen magnum into the cervical canal
chiari malformation
___: rare disorder characterized by abnormal fluid filled slits or clefts in the cerebral hemispheres
schizencephaly
schizencephaly is strongly associated with what other things
- absent CSP
- absence of CC
- septo optic dysplasia
___: a posterior fossa cyst superiorly displaces an intact cerebellar vermis
Blake pouch cyst
___: cystic dilation of the 4th ventricle that protrudes into the fossa
dandy walker malformation
S/A dandy walker malformation
- cystic structure in posterior fossa
- CM>10mm
- splayed cerebrellar lobes
- enlarged 4th vent
- ventriculomegaly or hydrcephalus
what structure in the brain collects the two hemispheres
corpus callous
CC should be fully developed by what week
18
___: enlarged posterior horns and small frontal horns of the lateral ventricles
coloprocephaly
S/A agenesis. of CC
- coloprocephaly
- sunburst sign
- absent pericallosal artery
what is the most common finding associated with septa optic dysplasia
absence of CSP
___: >10mm CM with intact cerebellar vermis
megacisterna magna
___: abnormalities caused by incomplete cleavage and rotation of the early forebrain
holoprosencephaly
holoprosencephaly is most commonly seen with trisomy __
13
what are the different types of holoprosencephaly
- alobar
- semilobar
- lobar
S/A alobar holoprosencephaly
- single c shaped ventricle
- absent fal
- no third ventricle
- no CSP
S/A semi lobar holoprosencephaly
- rudimentary cerebral lobes
- cerebral hemispheres and ventricles are partially separated
- incomplete fusion of thalamus
S/A lobar holoprosencephaly
- absent CSp
- anterior horns of ventricles remain fused
___: abnormally large brain
megalencephaly
___: multiple cyst formations within the cerebral tissue that can communicate with the ventricle system
porencephlaly
megalencephaly is associated with what
- beckwith Wiedemann syndrome
- achondroplasia
- neurofibromatosis
- tuberous sclerosis
porencephaly is associated with what
-intracranial hemorrhage
___: smooth brain surface
lissencephaly
choroid plexus cyst is a normal anatomic variant if what
mo other abnormalities are detected
AV malformation in the brain
vein of Galen aneurysm
vein of Galen aneurysm
- hydrops
- fluid accumulation
- congestive heart failure
___: destruction of cerebral tissue during fetal development
hydranencephaly
S/A hydranencephaly
- fluid filled sacs of CSF in cranial cavity
- polyhydramnios
- varying amounts of tissue may remain as atrophy and necrosis occurs
what is a common complication found in premature infants
intracranial hemorrhage
___: collection of blood outside of the cerebral hemispheres
subarachnoid hemorrhage
intracranial calcifications are usually related to what
- intrauterine infections
- CMV
- TORCH
what is the most common fetal intracranial abnormality associated with CMV
hyperechoic periventricular halo and septations within the occipital horns of the lateral ventricles
___: fluid accumulation between the dura and brain tissue
intracranial arachnoid cysts
what are the most common intracranial tumors
teratomas
___: enlarged choroid plexuses
choroid plexus papillomas
choroid plexus papillomas are associated with what
ventriclomegaly and enlarged subarachnoid space
