Subarachnoid Haemorrhage

Question 1

How common are Sub-Arachnoid Haemorrhages?

Answer 1

5% of strokes

Question 2

What are the common sx of a SAH?

Answer 2

Thunderclap headache (+/- sentinel headache)
Vomiting (post headache)
Photophobia
Increasing drowsiness/coma
Focal signs (raised ICP, cerebral vasospasm, locate lesion)

Question 3

What are the common signs of a SAH?

Answer 3

Neck stiffness
Kernig’s +ve (6hrs to develop)
Papilloedema (+/- retinal haemorrhages)

Question 4

What are the characteristics of a thunderclap headache?

Answer 4

Develops over seconds
Devastating in intensity
Often occipital
Often comes on during transient HTN (exercise/sex)

Question 5

What is a sentinel headache?

Answer 5

Smaller headache due to warning leak from aneurysm

Question 6

What are the common predisposing abnormalities to SAH?

Answer 6

Berry aneurysm (70%)
AV malformations (10%)
No lesion (20%)

Question 7

What is a Berry Aneurysm?

Answer 7

Developmental aneurysm in circle of Willis/adjacent arteries

Question 8

Where do Berry Aneurysms commonly form?

Answer 8

Anterior communicating artery (most common)
Posterior communicating artery (bifurcation from ICA)
Middle cerebral artery (at bifurcation/trifurcation)

Question 9

What are the risk factors for Berry Aneurysms?

Answer 9

Polycystic Kidney Disease
FH
Smoking
HTN
Ehlers-Danlos/Marfans

Question 10

What is a common mass effect of Berry Aneurysms?

Answer 10

Painful 3rd nerve palsy

Question 11

What is an arteriovenous malformation?

Answer 11

Congenital collection of abnormal arteries/veins
Tendency to rebleed (10%)
Can cause epilepsy (focal)

Question 12

What are the potential complications of a SAH?

Answer 12

Death (30%)
Rebleed
   -aneurysms after 3-4/7
   -avm after years
Hydrocephalus (fibrosis in CSF pathways)
Cerebral vasospasm (delayed ischaemic damage)

Question 13

What are the appropriate investigations in a suspected SAH?

Answer 13

Bloods - FBC, U&Es, LFT, ESR, clotting
CT - blood seen w/i 48hrs, quantity = prognosis, AVM visible on CT
LP - if CT normal, >12hr after sx onset, CSF will be xanthochromic
CT/MRI angiography - determines underlying vascular anatomy

Question 14

What is the appropriate management of suspected SAH?

Answer 14

4wks bed rest
HTN control
Nimodipine (prevents vasospasm, reduces mortality)
IV fluids
Analgesia, anti-emetics
Stool-softeners

Question 15

What is the neurosurgical management of suspected SAH?

Answer 15

Coiled by interventional radiology

Gamma knife therapy