CNS: Developmental Anomalies Flashcards Preview

Pathoma > CNS: Developmental Anomalies > Flashcards

Flashcards in CNS: Developmental Anomalies Deck (24)
Loading flashcards...
1
Q

Neural plate forms what

A

neural tube

2
Q

Along what axis does the neural tube run

A

cranial-caudal axis of embryo

3
Q

what does the wall of the neural rube form

A

central nervous system tissue

4
Q

The hollow lumen of the neural tube forms what

A

ventricles and spinal cord canal

5
Q

What does the neural crest form

A

peripheral nervous system

6
Q

Neural tube defects arise from what

A
  • incomplete closure of neural tube

- low folate levels prior to conception

7
Q

How are neural tube defects detected

A
  • during prenatal care

- elevated alpha-fetoprotein (AFP) in amniotic fluid and maternal blood

8
Q

What is anencephaly

A

absence of skull and brain

-disruption of cranial end of neural tube

9
Q

What does an anencephaly child look like

A

‘frog-like’ appearance

10
Q

What gets disrupted during pregnancy in anencephaly

A
  • maternal polyhydramnios

- fetal swallowing of amniotic fluid is impaired

11
Q

What is spina bifida

A

failure of the posterior vertebral arch to close

  • vertebral defect
  • disruption of caudal end of neural tube
12
Q

How does spina bifida occulta present clinically

A

dimple or patch of hair overlying the vertebral defect

13
Q

Meningocele

A

protrusion of meninges

14
Q

Meningomyelocele

A

protrusion of meninges and spinal cord

15
Q

What is the most common cause of hydrocephalus in newborns

A

cerebral aqueduct stenosis

16
Q

What is cerebral aqueduct stenosis

A
  • congenital stenosis of channel that drains cerebrospinal fluid from 3rd ventricle into 4th ventricle
  • accumulation of CSF in ventricular space
17
Q

Where is CSF produced

A

choroid plexus lining the ventricles

18
Q

what is the flow of CSF fluid

A
  • lateral ventricles to 3rd ventricle via interventricular foramen of Monro
  • 3rd ventricle into 4th ventricle via cerebral aqueduct
  • 4th ventricle into subarachnoid space via foramina of Magendie and Luschka
19
Q

clinical presentation for cerebral aqueduct stenosis

A

enlarging head circumference due to dilation of ventricles

- cranial suture lines are not fused

20
Q

Dandy Walker Malformation

A
  • congenital failure of cerebellar vermis to develop

- dilated 4th ventricle (posterior fossa) with an absent cerebellum

21
Q

What other abnormality does Dandy Walker Malformation usually accompany

A

hydrocephalus

22
Q

What is Arnold-Chiari Malformation (Type II)

A

Congenital downward displacement of cerebellar vermis and tonsil through the foramen magnum

23
Q

Obstruction of CSF flow commonly results in what for Arnold-Chiari malformation (Type II)

A

hydrocephalus

- occlusion of 4th ventricle

24
Q

Arnold-Chiari malformation (Type II) is associated with what

A
  • Meningomyelocele

- Syringomyelia