Congenital Malformations - Fremont-Smith Flashcards
pregnant women X-ray
damage is real risk
critical period for malformation
3-8 weeks gestation
malformation
flawed development
-no gliosis
disruption
destruction of normal brain
-yes gliosis
radiation
risk with malformation and disruption
timing of exposure
important for malformations and disruptions
ex/ CMV
- before midgestation- microcephaly and polymicroglyia
- third trimester - encephalitis
neural tube defects
neural tube closure defects
axial mesodermal defects
tail bud defects
cause of neural tube defect
folate deficiency
valproic acid
hyper/hypo glucose
no brain in anencephaly
amniotic fluid toxic
NT closure defect
anencephaly
chraniorachischisis
myelomeningocele
axial mesodermal defects
closed - split cord
herniation - encephalocele or meningocele
tail bud defect
spina bifida occulta
low split cord
hydromyelia
ciliopathy
NT closure defects
most common neural tube defect
anencephaly
detect on US
often with spina bifida
elevated alpha-fetoprotein and AChE
anencephaly
association of anencephaly
adrenal hypoplasia - no hypothalamus
craniorachischisis
all open neural tube
myelomeningocele
herniation of CNS through vertebral defect
often lumbosacral
risk of infection
surgical correction
meningocele
vertebral defect herniation - no CNS tissue
spina bifida occulta
no skin defect - may be hair tuft
ciliopathies
meckel gruber syndrome
encephalocele
defect or mesoderm development (skull)
herniation through axial defect of skull
meninges herniate with brain tissue
meckel gruber syndrome
with encephalocele
enlarged kidneys
polydactylyl
kinesin
anterograde transport
dynein
retrograde transport
mutated polycystin 1 or 2
Wnt and Hedgehog signaling dysfunction
loss of cell polarity
cystic tubular expansion
polycystic kidney disease
hydromyelia
over distension of central canal
pain in neck / numb shoulders
HAs
leg or hand weakness
problem walking
poor bowel and bladder control
small posterior fossa
chiaria malformations
larger posterior fossa
dandy-walker malformation
chiaria type 1
herniation cerebellar tonsil
often with syringomyelia - central cord larger and liquefy
-obstructed flow of CSF
no neural tube defect
cape like loss of pain and temp sensation
chiari malformation imaging
best on MRI
chiari type 2
with myelomeningocele
shallow posterior fossa and large foramen magnum
-herniate vermis and tonsils
with hydrocephalus
dandy walker malformation
larger posterior fossa
absence of vermis
often with hydrocephalus
atresia of foramen of luschka
obstructive hydrocephalus
obstruction of foramen of monro, third ventricle, aqueduct, foramen of luschka, SA space fibrosis, defective filtration of CSF, hydrocephalus ex vacuo
hydrocephalus ex vacuo
dilation of cerebral ventricles due to loss of brain tissue
with wasting brain diseases
damage with hydrocephalus
periventricular white matter - lose myelin and axons
holoprosencephaly
4-6 week gestation
absence of cleavage of prosencephalon
maternal DM, toxo, syphilis, rubella, FAS
associated with patau - trisomy 13
mutation of sonic hedgehog
midline facial and CNS structure defects
like holoprosencephaly
cyclopia, cleft lip
with holoprosencephaly
agenesis of corpus callosum
with other cerebral abnormalities
asymptomatic or seizures/psychomotor retardation
abnormal neuronal-glial proliferation or apoptosis
microcephaly
megalencephaly
abnormal neuronal migration
periventricular nodular heterotopia
lissenephaly
cobblestone cortex
abnormal cortical organization
polymicrogyria
focal cortical dysplasia
as germ cells develop
climb glial scaffolds
last cells are oligodendrocytes
-no myelin early - susceptible to damage
subcortical band heterotopia
neurons migrate half way
periventricular nodular heterotopia
neurons do not migrate at all
cobblestone cortex
neurons overshoot cortex and end up in SA space
late stage migration and organization interrupted
polymicrogyria
alcohol
affects process of neuron migration
fewer or more neurons produced than normal
microcephaly
megalencephaly
lissencephaly
smooth brain
defective neuron migration
LIS1 mutation
no gyri
microtubule motor protein and microtubular dysfunction
polymicrogyria
increased number of gyri
disrupted neuron migration
focal cortical dysplasia
most frequent removed brain tissue in epilepsy**
intractable seizures and cognitive impairment
FCD pathology
abnormal cortical with loss of normal layering of germ cells
often have hippocampal sclerosis - older patients
trisomy 18
quad screen all down
trisomy 21
beta-hcg and inhibin A elevated
AFP and estriol decreased
