Case 1 - Neural Tube Defects

Question 1

how many neurones are in the brain

Answer 1

100 billion

Question 2

how many transmitters are in the brain

Answer 2

40 known transmitters

Question 3

how many transmitters does each neurone produce

Answer 3

a minimum of 2

Question 4

how many genes are associated with autism

Answer 4

2,500

Question 5

what is lishencephaly

Answer 5

the failure of cells to stop migrating and end up with a smooth brain

Question 6

epidemiology of hydrocephalus

Answer 6

1:500

Question 7

how does the neural tube close?

Answer 7

there is a medial hinge point at the bottom and a dorsal lateral hinge point at the top.

Question 8

what is folate required for

Answer 8

for cell division so therefore a folate deficiency causes failure of the closure of the neural tube

Question 9

is anencephaly compatible with life

Answer 9

no.

Question 10

what is encephalocele

Answer 10

a bone defect and protrusion of the meninges out of the bone defect and is filled with CSF

Question 11

why is there a tuft of hair on SB occults

Answer 11

shows the CSF is leaking and is stimulating the hair follicles to grow as CSF has growth factors.

Question 12

why is it bad if the SB baby is exposed to amniotic fluid

Answer 12

because it includes toxic urine which impaired baby’s CNS growth

Question 13

how much CSF do we produce

Answer 13

every day we make 0.3mls a minute of CSF

Question 14

why do people with hydrocephaly have sunset eyes

Answer 14

there is pressure on the ocular motor nerve and eyes fall down as there is no muscle tone

Question 15

international recommendations for Folic acid

Answer 15

400 micrograms per day - 3 months before and 3 months into pregnancy

Question 16

what else is folate required for

Answer 16

DNA production and methylation

Question 17

what is the new preventative for SB

Answer 17

combination of folic acid and inositol can help with folate resistant SB

Question 18

why do babies develop hydrocephalus after birth

Answer 18

in a large number of cases of SB being closed after brith, these babies develop hydrocephalus as the CSF exit is now closed and the normal routes have not opened.

Question 19

how does hydrocephalus relate to Arnold Chiara

Answer 19

H accompanies nearly 50% of ACM cases due to the Arnold Chiara malformation blocking CSF exit from the ventricles

Question 20

folic acid epidemiology

Answer 20

prevents up to 70% o NTDs

Question 21

how much CSF does the chord plexus form

Answer 21

75% of the fluid

Question 22

how much CSF does the third ventricle add

Answer 22

10%

Question 23

how much CSF does the fourth ventricle add

Answer 23

5-10%

Question 24

is CSF being secreted into the ventricles a passive process?

Answer 24

no, the CSF is secreted against pressure into the ventricles

Question 25

how does CSF move

Answer 25

by producing more behind it

Question 26

describe the initial development of the cortex

Answer 26

the initial development is in two layers - the marginal zone which are CR cells and the sub-plate cells which are the first two layers made

Question 27

how many layers of cortex are made between the first two layers

Answer 27

6 layers

Question 28

what do stem cells have

Answer 28

radial fibres that connect top to bottom

Question 29

what do these radial fibres do

Answer 29

climb up the layers and are then released to make a new layer at the top of the cortex.

Question 30

what do the CR cells in the marginal zone express and secrete

Answer 30

reelin

Question 31

what happens to the CSF if there is no pressure

Answer 31

CSF cannot exit the 4th ventricle into the subarachnoid space

Question 32

what happens without the CSF at the top of the brain

Answer 32

the signalling pathways are still there but without the CSF at the top of the brain, the cells do not get the message to migrate

Question 33

when does hydrocephalus occur

Answer 33

once high volume CSF output starts

Question 34

how is hydrocephalus termed in terms of development

Answer 34

it is an arrest of development

Question 35

how many proteins does CSF contain

Answer 35

2,500 proteins