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3MB Neurology (the director's cut) > Hydrocephalus > Flashcards

Flashcards in Hydrocephalus Deck (21)
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1
Q

what is hydrocephalus

A

an excessive accumulation of CSF leading to the enlargement of the brain ventricles

2
Q

mean csf pressure

A

10mmHg (>15 = abnormally high)

3
Q

cfs produced per day

A

500mls

4
Q

where is csf absorbed

A

arachnoid granulations

5
Q

CSF four functions

A

Buoyancy (reduced brain weight by 96%)
Accommodates physiological changes in vascular volumes by displacing into spinal canal
Provides micronutrients
Homeostasis

6
Q

2 types of hydrocephalus

A

Communicating + non-communicating

7
Q

communicating hydrocephalus is due to …

A

impaired arachnoid granulations

8
Q

3 possible cause of non-communicating hydrocephalus

A

tumour
colloid cyst obstructing 3rd ventricle
stenosis of aqueduct

9
Q

How can you tell a non-communicating (obstructive) hydrocephalus on CT/MRI

A

4th ventricle is smaller than 3rd or laterals

10
Q

Causes of congenital hydrocephalus

A
aqueductal stenosis
chiari malformation (often type 1)
11
Q

Clinical features of congenital hydrocephalus

A

dilated scalp veins (bulging or tense fontanelle)
Increased head circumference (thin and shiny scalp)
‘setting sun’ appearnace

12
Q

Clinical features of acquired hydrocephalus

A
Headaches
Vomiting
Impaired upgaze (compression on tectal plate)
raised ICP
Papilloedema
13
Q

Investigations for hydrocephalus

A

CT for acute diagnosis

MRI for assessing cause and location of obstruction

14
Q

2 main surgical managements of hydrocephalus

A

VP shunt

ETV

15
Q

Requirements for ETV to work

A

functioning CSF absorption pathways (non-communicating hydrocephalus) and a patent subarachnoid space.

16
Q

If etv doesn’t work then…

A

to VP shunt

17
Q

default surgery for communicating hydrocephalus

A

VP shunt

18
Q

what does ETV do?

A

creates direct pathway from 3rd ventricle to subarachnoid space

19
Q

complications of VP shunt

A

Over drainage
Under drainage
infection

20
Q

Presentation of blocked shunt?

A

headache and vomiting,
sunsettining in children
papiloedema (blindness)
lack of upgaze in adults

21
Q

Management of blocked shunt?

A

Tap the shunt valve (risk of infection) send CSF to microbiology
CT head to show hydrocephalus
Urgently repair/replace shunt