Neurology - Embryology Flashcards Preview

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Flashcards in Neurology - Embryology Deck (41)
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1

What is the function of the notochord?

Inducing overlying ectoderm to differentiate into neuroectoderm, and form the neural plate -> give rises to the neural tube and neural crest cells

2

What is the adult remnant of the notochord?

Nucleus pulposus of the intervertebral disc

3

What is the alar plate?

Dorsal: sensory

4

What is the basal plate?

Ventral: motor

5

When is the neural tube formed?

Day 18-21 (3 weeks)

6

What are the three primary vesicles of the developing brain?

Prosencephalon (Forebrain)
Mesencephalon (Midbrain)
Rhombencephalon (Hindbrain)

7

What are the five secondary vesicles of the developing brain?

Telecephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon

8

Adult derivative of: telecephalon

Cerebral hemispheres
Lateral ventricles

9

Adult derivative of: diencephalon

Thalamus
Third ventricle

10

Adult derivative of: mesencephalon

Midbrain (Medulla)
Aqueduct

11

Adult derivative of: metencephalon

Pons and Cerebellum
Upper part of the fourth ventricle

12

Adult derivative of: myelencephalon

Lower part of the fourth ventricle

13

When does neural tube defects occur?

4th week

14

What is neural tube defects associated with?

low folic acid

15

What lab values suggest neural tube defect?

Elevated AFP
Elevated acetylcholinesterase

16

What is a confirmatory test for neural tube defect?

Elevated acetylcholinesterase

17

Spina bifida occulta

failure of bony spinal canal to close
no structural herniation, usually lower vertebral level; dura is intact

associated with tuft of hair or skin dimple

18

Meningocele

Meninges (but not spinal cord) herniate through spinal canal defect

19

Meningomyelocele

Meninges and spinal cord herniate through spinal defect

20

Anencephaly

Malformation of anterior neural tube - no forebrain, open calvarium (frog-like appearance)

21

Lab values for anencephaly

High AFP, polyhydramnios (no swalloing center)

22

What is anencephaly associated with?

materal diabetes (Type I)

23

What can decrease risk of anencephaly?

maternal folate supplement can decrease risk

24

Holoprosencephaly

Failure of left and right hemispheres to separate; usually weeks 5-6

25

What is suggested to be mutated in holoprosencephaly?

sonic hedgehog signaling pathway

26

What are moderate and severe forms of holoprosencephaly associated with?

cleft lip/palate - moderate
cyclopia - severe

27

Cerebral aqueduct stenosis

Accumulation of CSF in ventricular space - most common cause of hydrocephalus in newborns

28

Presentation of cerebral aqueduct

enlarging head circumference due to dilation of ventricles (cranial suture lines not fused)

29

What is dandy-walker malformation?

Congenital failure of cerebellar vermis to develop
Massively dilated 4th ventricle with absent cerebellum often accompanied by hydrocephalus

30

What is dandy-walker associated with?

hydrocephalus and spina bidifa