neural tube defects pt 2

arnold-chiari malformation type 2: failure to fuse at what region, …-cele is usually present, head shape, posterior fossa appearance

lumbar, myelomeningo, lemon, no cisterns manga, banana shaped cerebellum

extraventricular/communicating hydrocephalus: 2 broad causes, first areas to dilate, mass overproducing CSF

overproduction, malabsorption, subarachnoid spaces and cisterns, choroid plexus papilloma

3 types of dorsal induction errors

anencephaly, encephalocele, spina bifida

anencephaly: definition, most common in what population, ultrasound appearance head, …hydramnios, abnormally high lab

absence of skull and cerebral hemispheres, diabetics, frog eyes and no skull, poly, afp

encephalocele: caused when brain…, typically location 2 names, 2 associated anomalies, …hydramnios

protrudes through skull, posterior, occipital, microcephaly, hydrocephalus, poly

syndrome presenting with encephalocele, cystic renal dysplasia, polydactyly

mechel-gruber

4 errors of ventral induction

holoprosencephaly, dandy-walker complex, megacisterna magna, arachnoid cyst

holoprosencephaly: incomplete …, 3 types from most severe to least, … facial defects, associated with which trisomies

cleavage of cerebral hemispheres, alobar, semilobar, lobar, midline, 13, 18

holoprosencephaly: alobar appearance, semilobar, lobar

monoventricle with fused thalami and no falx, separate posterior horns and no falx, anterior horns remain fused

mega cisterns magna: over … mm, associated with which trisomy, 2 differentiations from dandy walker

10, 18, intact vermis and normal ventricles

arachnoid cyst: location, communicate with ventricles?, show color flow?

anywhere in skull, no, no

hydranencephaly: absence of …, 2 intact structures, occlusion of … arterIES, ultrasound appearance (2) … hydramnios

cerebrum, cerebellum, midbrain, internal carotid, macrocephaly, anechoic cranium, poly

schizencephaly: abnormal development of … areas (2), obstruction of … arterIES, associated with what 3 consequences

parietal, temporal, middle cerebral, developmental delay, epilepsy, motor abnormalities

lissenecephaly: brain appearance, diagnosed in …, more commonly seen in … neonates

smooth, late 3rd trimester, premature

microcephaly: …head, 2 causes, abnormal measurement and ratios

small, craniosynostosis, meckel-gruber, bpd, bpd/fl, ac/hc

macrocephaly: …head, enlarged brain is called …

large, megalencephaly

agenesis of the corpus callosum: absence of what structure, displacement of … laterally creating a “….” shape, displacement of … superiorly, many sulci create the “…” appearance, typically seen with the presence of other anomalies?

csp, lateral ventricles, tear drop, 3rd ventricle, sunburst, yes

absent corpus callosum creates “tear drop” shaped lateral ventricles. the … horn is pointed, the … horn is dilated

anterior, posterior

intracranial hemorrhage: echogenicity of blood compared to choroid plexus, dilation of …, need to differentiate from …

hyperechoic, ventricles, choroid

choroid plexus cyst: must disappear by … weeks, associated with trisomy …

26, 18

intracranial calcifications: usually due to …, prognosis

infection, poor

infection: ultrasound appearance - head size, ventricles, vent. wall echogenicity, … seen due to necrosis

microcephaly, ventriculomegaly, increased, calcifications

most common OB infection

cytomegalovirus