Hydrocephalus

Question 1

Where is CSF produced

Answer 1

choroid plexus (pia mater)

Question 2

What is the distribution of CSF between intracranial and spine in adults?

Answer 2

50% intracranial

50% spinal

Question 3

What is the volume of CSF in adults?

Answer 3

150mls

Question 4

At what rate does the choroid plexus produce CSF?

Answer 4

450mls/day (3-4x turnover)

Question 5

How much of a sample of CSF can you take?

Answer 5

up to 20 ml

Question 6

What is the function of CSF?

Answer 6

Buoyancy (stops brain from crushing itself)
Protection
Reservoir for maintaining ICP
Excretion of metabolic waste
Exit route for pineal secretions to the pituitary gland

Question 7

Where is the choroid plexus located?

Answer 7

Choroid plexus found in each of the four ventricles:
lateral ventricles
third ventricle
fourth ventricle

Question 8

Where is CSF absorbed?

Answer 8

arachnoid granulations in the superior saggital sinus

Question 9

In which compartment does CSF flow?

Answer 9

subarachnoid space

Question 10

What are the two types of flow of CSF?

Answer 10

Bulk flow (inside of brain to outside) and pulsatile flow (and in time with heartbeat)

Question 11

Where is CSF produced in infants?

Answer 11

via minor pathway. Major pathway in adults is via choroid plexus

Question 12

At what age does the major pathway for production and absorption of CSF take over?

Answer 12

2 years

Question 13

How is Hydrocephalus classified?

Answer 13

communicating and non-communicating/obstructive

ateiological

Question 14

In which cause of hydrocephalus can you safely perform LP?

Answer 14

communicating (not obstructive!!)

Question 15

How to distinguish between raised ICP and hydrocephalus?

Answer 15

only by imaging! Hydrocephalus will present with similar symptoms and signs as raised ICP

Question 16

Which imaging is used for raised ICP/hydrocephalus?

Answer 16

CT or MRI

Question 17

Why can you perform a LP in communicating but not obstructive hydrocephalus?

Answer 17

continuous gradient of pressure in communicating (same pressure in spinal cord and brain) whilst in obstructive there is a gradient of pressure- high in head and low in spinal cord, therefore removing fluid could increase gradient and brain structures could be forced downwards

Question 18

Which structure is at risk if you perform LP in patient with obstructive hydrocephalus?

Answer 18

basilar artery, causing brainstem stroke

Question 19

Name one aetiological cause of hydrocephalus

Answer 19

chiari malformation or spina bifida
aqueductal stenosis (x-linked)
Dandy walker complex
Congenital arachnoid cysts
Atresia of foramen of munro

Question 20

Name two acquired causes of hydrocephalus

Answer 20

haemorrhage
traumatic head injury
infection
tumour

Question 21

What are the symptoms of hydrocephalus

Answer 21

exactly the same symptoms as for raised ICP
headache
nausea and vomiting
blurred vision
drowsiness or reduced GCS
developmental delay

Question 22

What is Parinaud’s syndrome?

Answer 22

inability to move the eyes up and down= setting sun sign. Sign of hydrocephalus

Question 23

What is the management of hydrocephalus?

Answer 23

Eliminate obstruction (ventric tumour)
Divert CSF flow elsewhere (shunt)
Reduce production of CSF (choroid plexectomy)

Question 24

How can you divert CSF flow?

Answer 24

external ventricular drain, very quick and easy procedure

Question 25

Where can CSF be shunted to?

Answer 25

peritoneum
pleural cavity
right atrium