Perinatal Disorders, malformation, and defects

Question 1

HIE in infancts

Answer 1

water shed lesions most characteristic
can see calcifications
triangular appearance of brain d/t watershed necrosis
multicystic encephalopathy

Question 2

moderate ischemia in infants

Answer 2

causes mainly cortical damage in border zones between major aa territories
a parasagittal band of Cx taht arches from frontal to occipital pole

Question 3

severe ischemia in infants

Answer 3

damages deep nuclei and brainstem

Question 4

CMV infections

Answer 4

can also induce ischemic changes in ventricles

Question 5

periventricular leukomalacia (PVL)

Answer 5

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)

Question 6

germinal matrix hemorrhage

Answer 6

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

Question 7

porencephaly

Answer 7

fluid filled cavity confined to parenchyma

Question 8

schizencephaly

Answer 8

lesion which is in the parenchyma but communicated with subarachnoid space

Question 9

hydranencephaly

Answer 9

cerebrum replaces by cyst

d/t loss of blood supply from major vessel -> ischemia -> autodigestion -> cyst

Question 10

bilirubin encephalopathy /kernicterus

Answer 10

acquired metabolic encephalopathy of neonate

unbound, unconjugated bilirubin crosses BBB b/c it is lipid soluble and penetrates neuronal and glial membranes

Question 11

critical period for malformations and disruptions?

Answer 11

wk3-8

Question 12

malformation

Answer 12

flawed development
usually midline, b/l, symmetric
no gliosis
carries recurrence risk that can be calculated

Question 13

disruption

Answer 13

destruction of normal brain
focal and asymmetric
does have gliosis (inflammation and calcification)
do not recur unless exposure recurs or continues

Question 14

radiation

Answer 14

presents as a spectrum btwn malformation and disruption

Question 15

early CMV infection

Answer 15

microencephaly and polymicrogyria

Question 16

3rd trimester CMV infection

Answer 16

encephalitis

Question 17

causes of NT defects

Answer 17

deficiencies: folate, inositol, B12, zinc
folate antagonisits
glycemic dysregulation
histone deactylase inhibitors
thermal dysregulation

Question 18

folate antagonists

Answer 18

carbamazepine
fumonisin
trimethoprim

Question 19

histone deacetylase inhibitors

Answer 19

valproic acid

Question 20

NT closure defects

Answer 20

anencephaly
craniorachischisis 
myelomeningocele
spina bifida 
menigocele

Question 21

anencephaly

Answer 21

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

Question 22

craniorachischisis

Answer 22

hindbrain-cervial jnx of NT does not zip closed

Question 23

meylopmenigocele

Answer 23

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

Question 24

axial mesodermal defects

Answer 24

closed defect- split cord (high)

herniation defect- encephalocele, menigocele

Question 25

encephalocele

Answer 25

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

Question 26

meckel gruber syndrome

Answer 26

``` rare ciliopathic, genetic disorder, characterized by renal cystic dysplasia CNS malformations (encephalocele) hepatic developmental defects pulmonary hypoplasia d/t oligohydramnios ```

Question 27

tail bud defects

Answer 27

spina bifida occulta split cord (low) hydromyelia

Question 28

hydromyelia

Answer 28

``` 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 ```

Question 29

posterior fossa anomalies

Answer 29

brainstem and cerebellum chirari malformations I and II dandy-walker malformation

Question 30

chiari type I

Answer 30

``` 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 ```

Question 31

chiari type II

Answer 31

``` aka arnold-chiari malformation almost invariably w/lumbosacral myelomeningocele craniolucunia low torcula, short fenesstrated falx hydrocephalus ```

Question 32

craniolacunia

Answer 32

shallow posterior fossa and enlarged foramen magnum low tentorial insertion herniation of vermis and tonsils

Question 33

dandy walker malformation

Answer 33

large posterior fossa absence of vermis usually associated with hydrocephalus

Question 34

obstruction of formaina of monro

Answer 34

colloid cyst | tuberous sclerosis

Question 35

obstruction of 3rd ventricle

Answer 35

craniopharyngoma pilocytic astrocytoma germ cell tumors

Question 36

obstruction of aqueduct

Answer 36

aqueductal stenosis/atresia | posterior fossa tumors

Question 37

obstruction of formaina of luschka or 4th venticle

Answer 37

``` chiari malformation Dandy walker meningitis subarachnoid hemorrhage posterior fossa tumros ```

Question 38

fibrosis of subarachnoid space

Answer 38

meningitis subarachnoid hemorrhage menigeal dissemination of tumors

Question 39

defective filtration of CSF

Answer 39

postulated for low-pressure hydrocephalus

Question 40

hydrocephalus ex vacuo

Answer 40

dilation of cerebral ventricels d/t loss of brain tissue

Question 41

idiopathic external hydrochephalus

Answer 41

condition characterized by increased CSF volume and expansion of subarachnoid space w/o ventricular brain atrophy, intracranial HTN, usually resolves w/o Tx

Question 42

holoprocencephaly

Answer 42

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

Question 43

risks for holoprocencephaly

Answer 43

``` maternal DM toxoplasmosis syphillis rubella FAS genetic ```

Question 44

agenesis of corpus callosum

Answer 44

``` can be associated w/ arnold chiari malformation dandy walker anermann syndrome schizencephaly sporadic or rarely famililar asymptomatic -> retardation ```

Question 45

abnormal neuronal-glial proliferation and/or apoptosis

Answer 45

microcephaly | macrocephaly

Question 46

abnormal neuronal migration

Answer 46

periventricular nodular heterotopia lissencephaly cobblestone Cx congeital muscualr dystrophy

Question 47

abnormal cortical organization

Answer 47

polymircogyria | focal cortical dysplasia

Question 48

lissencephaly

Answer 48

``` smooth brain defective neuronal radial and tangential migration absence of gyri LIS1 mutation microtubule dysfunction ```

Question 49

polymicrogyria

Answer 49

``` diffuse or focal b/l or u/l symmetric or asymmetric seizures, retardation, spasticity rarely inherited ```

Question 50

focal cortical dysplasia (FCD)

Answer 50

- 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

Question 51

FAS

Answer 51

affects corpus callosum, cerebral Cx, hippocampus, cerebellum