Hydrocephalus

Question 1

where the CSF is produced

Answer 1

choroid plexus that lines the lateral ventricles

Question 2

where is CSF drained

Answer 2

through the arachnoid granulations into the superior sagittal sinus

Question 3

how many times a day does CSF volume replace itseld

Answer 3

3/4

Question 4

cerebral aqueduct connects what ventricles

Answer 4

3rd and 4th

Question 5

what makes arachnoid granulations open to CSF

Answer 5

pressure becoming greater than dural venous sinus pressure and opening one-way valves

Question 6

true/false CSF production uses ATP

Answer 6

true

Question 7

true/false CSF production uses ATP

Answer 7

false - passive process driven by pressure gradient

Question 8

two types of hydrocephalus

Answer 8

communicating and non-communicating

Question 9

4 causes of a communicating hydrocephalus

Answer 9

infection, subarachnoid haemorrhage, post-operative and head trauma

Question 10

infection can cause non/communicating hydrocephalus

Answer 10

both

Question 11

how does a subarachnoid haemorrhage cause communicating hydrocephalus

Answer 11

increases ICP by increasing volume and also by the blood scarring the arachnoid granulations and obstructing reabsorption

Question 12

pathophysiology of non-communicating hydrocephalus

Answer 12

obstruction of the normal CSF pathway

Question 13

aquecuctal stenosis, tumours, cysts, infection, haemorrhage and congenital malformation may all cause what

Answer 13

non-communicating hydrocephalus

Question 14

which nerve is damaged in raised ICP

Answer 14

the 6th (trochlea) because it has the longest intercranial course

Question 15

3 Ws of normal pressure hydrocephalus

Answer 15

wet, wobbly and wacky

Question 16

scan used to view ventricles in raised ICP

Answer 16

CT

Question 17

two ratios of measuring ventricles on CT

Answer 17

Evan’s and ventricular index

Question 18

urgent treatment of hydrocephalus

Answer 18

urgent external ventricular drain

Question 19

long term treatment of hydrocephalus

Answer 19

a shunt –> can cause headache and infection

Question 20

where do shunts drain from and to

Answer 20

ventricle or spine to atria or peritoneum

Question 21

complication of an LP in raised ICP

Answer 21

herniation (coning)

Question 22

what hydrocephalus is a rare and preventable cause of dementia

Answer 22

normal pressure hydrocephalus

Question 23

what is contradictory about normal pressure hydrocephalus

Answer 23

LP in normal pressure but dilated ventricles on CT

Question 24

what type is a 3rd ventriculostomy an option

Answer 24

in non-communicating - opens the ventricle space back up

Question 25

brain receives how much of the cardiac output

Answer 25

15%

Question 26

cerebral perfusion pressure =

Answer 26

mean arterial pressure - intracranial pressure

Question 27

range of CPP that cerebral blood flow autoregulation can work

Answer 27

50-150mmHg

Question 28

carbon dioxide is a vasoconstrictor/dilator

Answer 28

vasodilation

Question 29

what cells make the blood brain barrier

Answer 29

astrocytes

Question 30

what does the monro-kelly doctrine tell us

Answer 30

when a new intracranial mass in introduced there will be a compensatory change in volume through decrease of venous blood or CSF to maintain a constant intracranial volume

Question 31

what do C waves correspond to

Answer 31

waves of blood pressure through systolic and diastolic

Question 32

what do B waves correspond to

Answer 32

breathing

Question 33

what do A waves correspond to

Answer 33

an abrupt elevation in ICP for 5-20 mins as high as 50/10mmHg

Question 34

what is Cushing's reflex

Answer 34

a nervous system response to reduce ICP by increasing BP, slowing heart rate and an irregular resp rate

Question 35

what is Cushing's triad

Answer 35

hypertension, bradycardia, irregular resp rate

Question 36

when do you see cushing's triad (i.e. in what condition)

Answer 36

coning

Question 37

presentation of coning

Answer 37

cushing's triad, altered mental status and cranial nerve defects

Question 38

treating raised ICP

Answer 38

head elevated fluids (mannitol or hypertonic saline) surgical decompression