17.1 Developmental Anomalies Flashcards
CNS developmental anomalies
-list them (4 general categories to know in pathoma)
- Neural tube defects (anencephaly, spina bifida)
- Cerebral aqueduct stenosis
- Dandy-Walker malformation (no vermis)
- Arnold-Chiari Malformation (type 2)–congenital herniation of tonsils/vermis
Cerebral aqueduct stenosis
- mech
- presentation
congenital stenosis of channel that drains 3rd to 4th ventricle
-enlarging head circumference due to dilation of ventricles (cranial suture lines not fused yet)
What is most common cause of hydrocephalus in newborns?
Cerebral aqueduct stenosis
Neural tube defects
- assoc with what during/before pregnancy
- How to detect during pregnancy?
- Low folate levels prior to conception
- Elevated AFP levels in amniotic fluid and maternal blood.
Arnold-Chiari malformation
- mech
- presentation
- assoc with what
congenital displacement downwards, of vermis and tonsils through foramen magnum
- hydrocephalus
- assoc with meningomyelocele
Anencephaly
- mech
- presentation (2)
- absence of skull and brain
- (disruption of cranial end of neural tube)
1. ‘frog’like appearance
2. maternal polyhydramnios (fetal swallowing is impaired)
Development of neural tube
-what does each part become (3)
(see picture)
- neural crest cells, become PNS
- neural tube wall, become CNS
- Lumen of neural tube, becomes ventricles and spinal cord canal
types of spina bifida (3)
- spina bifida occulta–path of hair overlying the defect
- meningocele–protrustion of meninges
- meningomyelocele–meninges and spinal cord
Frog like appearance
-what is this
anencephaly
Pregnant woman’s blood has elevated AFP, and so does the amniotic fluid
-think what
-possible neural tube defect
Dandy-Walker malformation
congenital failure of vermis to form
- massively dilated 4th ventricle, absent cerebellum
- hydrocephalus
Meningocele vs meningomyelocele
meningocele: protrusion of meninges
meningomyelocele–meninges and spinal cord
