Perinatal Disorders, malformation, and defects Flashcards
HIE in infancts
water shed lesions most characteristic
can see calcifications
triangular appearance of brain d/t watershed necrosis
multicystic encephalopathy
moderate ischemia in infants
causes mainly cortical damage in border zones between major aa territories
a parasagittal band of Cx taht arches from frontal to occipital pole
severe ischemia in infants
damages deep nuclei and brainstem
CMV infections
can also induce ischemic changes in ventricles
periventricular leukomalacia (PVL)
in preterm infants
cardiorespiratory abnormalities and sepsis increase risk
most vessels grow from superficial-> deep so the germinal cell layer at the edge of the ventricles is a watershed ares in the preterm infant
calcifications can occur in the necrotic tissue
basis of cerebral palsy (CP)
germinal matrix hemorrhage
frequent lesion in premature babies who have hyaline membrane disease and RDS
more common in babies weighing 500-750gm
major cause of morbidity and mortality, CP, and mental retardation
porencephaly
fluid filled cavity confined to parenchyma
schizencephaly
lesion which is in the parenchyma but communicated with subarachnoid space
hydranencephaly
cerebrum replaces by cyst
d/t loss of blood supply from major vessel -> ischemia -> autodigestion -> cyst
bilirubin encephalopathy /kernicterus
acquired metabolic encephalopathy of neonate
unbound, unconjugated bilirubin crosses BBB b/c it is lipid soluble and penetrates neuronal and glial membranes
critical period for malformations and disruptions?
wk3-8
malformation
flawed development
usually midline, b/l, symmetric
no gliosis
carries recurrence risk that can be calculated
disruption
destruction of normal brain
focal and asymmetric
does have gliosis (inflammation and calcification)
do not recur unless exposure recurs or continues
radiation
presents as a spectrum btwn malformation and disruption
early CMV infection
microencephaly and polymicrogyria
3rd trimester CMV infection
encephalitis
causes of NT defects
deficiencies: folate, inositol, B12, zinc folate antagonisits glycemic dysregulation histone deactylase inhibitors thermal dysregulation
folate antagonists
carbamazepine
fumonisin
trimethoprim
histone deacetylase inhibitors
valproic acid
NT closure defects
anencephaly craniorachischisis myelomeningocele spina bifida menigocele
anencephaly
initially brain protrudes thru defect of cranial vault -> mechanically and chemically destroyed
elevated alpha-fetoprotein and acetylcholinesterase in amniotic fluid and materal blood
usually detected on US
often accompanied by spina bifida
craniorachischisis
hindbrain-cervial jnx of NT does not zip closed
meylopmenigocele
herniation of CNS tissue thru vertebral defect
can occur at any level, but almost always lumbosacral
risk of infection
some loss of sensation/parlysis
surgical correction
axial mesodermal defects
closed defect- split cord (high)
herniation defect- encephalocele, menigocele
encephalocele
defect of cranial mesodermal development
herniation thru an axial mesoderm defect of skull
meningies herniate w/normal brain tissue
tissue in sac gets destroyed
75% occipital
linked to ciliopathies
meckel gruber syndrome
rare ciliopathic, genetic disorder, characterized by renal cystic dysplasia CNS malformations (encephalocele) hepatic developmental defects pulmonary hypoplasia d/t oligohydramnios
tail bud defects
spina bifida occulta
split cord (low)
hydromyelia
hydromyelia
over distension of central canal pain in neck, shoulders usually numb HAs leg or hand weakness numbness or loss of sensation in hands and feet problems with walking loss of bowel and bladder control spasticity and paralysis of legs
posterior fossa anomalies
brainstem and cerebellum
chirari malformations I and II
dandy-walker malformation
chiari type I
herniation of a peg of cerebellar tonsil can be asymptomatic neck pain lower CN palsies sleep apnea sudden death cerebellar ataxia hydrocephalus syringomyelia NO neural tube defect
chiari type II
aka arnold-chiari malformation almost invariably w/lumbosacral myelomeningocele craniolucunia low torcula, short fenesstrated falx hydrocephalus
craniolacunia
shallow posterior fossa and enlarged foramen magnum
low tentorial insertion
herniation of vermis and tonsils
dandy walker malformation
large posterior fossa
absence of vermis
usually associated with hydrocephalus
obstruction of formaina of monro
colloid cyst
tuberous sclerosis
obstruction of 3rd ventricle
craniopharyngoma
pilocytic astrocytoma
germ cell tumors
obstruction of aqueduct
aqueductal stenosis/atresia
posterior fossa tumors
obstruction of formaina of luschka or 4th venticle
chiari malformation Dandy walker meningitis subarachnoid hemorrhage posterior fossa tumros
fibrosis of subarachnoid space
meningitis
subarachnoid hemorrhage
menigeal dissemination of tumors
defective filtration of CSF
postulated for low-pressure hydrocephalus
hydrocephalus ex vacuo
dilation of cerebral ventricels d/t loss of brain tissue
idiopathic external hydrochephalus
condition characterized by increased CSF volume and expansion of subarachnoid space w/o ventricular brain atrophy, intracranial HTN,
usually resolves w/o Tx
holoprocencephaly
btwn 4th-6th week of gestation the forebrain is divided into 2 hemispheres
absence of this cleavage resutls in spectrum of malformations
common in Patau syndrome (trisomy 13)
maybe Shh mutations
risks for holoprocencephaly
maternal DM toxoplasmosis syphillis rubella FAS genetic
agenesis of corpus callosum
can be associated w/ arnold chiari malformation dandy walker anermann syndrome schizencephaly sporadic or rarely famililar asymptomatic -> retardation
abnormal neuronal-glial proliferation and/or apoptosis
microcephaly
macrocephaly
abnormal neuronal migration
periventricular nodular heterotopia
lissencephaly
cobblestone Cx
congeital muscualr dystrophy
abnormal cortical organization
polymircogyria
focal cortical dysplasia
lissencephaly
smooth brain defective neuronal radial and tangential migration absence of gyri LIS1 mutation microtubule dysfunction
polymicrogyria
diffuse or focal b/l or u/l symmetric or asymmetric seizures, retardation, spasticity rarely inherited
focal cortical dysplasia (FCD)
- sporadic developmental malformation of cerebral Cx -> intractable seizures and cognitive impairment
- MOST FREQUENT pathology of brain tissue removed in epilepsy surgery
- significant portion have hippocampal sclerosis which is most frequent lesion in older pts
FAS
affects corpus callosum, cerebral Cx, hippocampus, cerebellum
