Subarachnoid haemorrhage (SAH)

Question 1

what are the etiological causes of a SAH?

Answer 1

trauma
saccular (berry) aneurysms
AVM

less commonly;

• Ehlers danlos syndrome
• Marfans syndrome
• clotting disorders
• mycotic aneurysm (endocarditis)
• coarctation of the aorta

Question 2

what are differentials of a ‘thunderclap’ headache?

Answer 2

SAH 
Meningitis 
Migraine 
Call-fleming syndrome (reversible cerebral vasoconstriction)
Cervical arterial dissection

Question 3

what is the first line investigation in a suspected SAH?

Answer 3

CT head

Question 4

what investigations would you carry out if you suspected SAH?

Answer 4

CT head (firstly)

LP: blood, xanthochromia, bilirubin spectrophotometry

CT angiogram (if suspected aneurysm)

Question 5

how is a SAH managed?

Answer 5

1st line: bed rest and control hypertension (Nimodepine for 3 weeks)

treatment depends on the cause;

aneurysm;

• platinum coil via catheter
• surgical mechanical clip

AVM;

• end-vascular catheter glue injection
• microsurgery
• stereotactic radiotherapy

Question 6

what is xanthochromia and what does it indicate?

Answer 6

yellowing of the CSF
indicates degradation of blood
found 12 hours after SAH and remains for up to 2 weeks post

Question 7

what imaging modality is best used in the follow up of end-vascular treated aneurysms?

Answer 7

MRI with flare technology

Question 8

if a patient presents with a sudden onset severe headache and they were found to have meningitis, what is responsible for the headache?

Answer 8

meningeal micro abscess aneurysm rupture

Question 9

what sign might you observe in clinical examination of a patient with a SAH?

Answer 9

Positive Kernig’s sign

Flex the knee and hip to 90 degrees. subsequent flexion of the knee causes pain.

Question 10

what are presenting features of a SAH?

Answer 10

sudden onset headache (back of the head)
neck stiffness
loss of consciousness / drowsy
nausea/ vomiting

Question 11

what test can be done to certify that there is blood in the CSF on LP?

Answer 11

bilirubin spectrophotometry

Question 12

where do saccular (berry) aneurysms form and what are the most common sites they are found at?

Answer 12

Occur in the circle of willis and adjacent arteries, typically at junctions

Most common;

• Posterior communicating and internal carotid artery
• Anterior communicating and anterior cerebral artery
• Bifurcation or Trifurcation of the middle meningeal artery

Question 13

what is the most common cause of a painful CN III palsy?

Answer 13

posterior communicating artery aneurysm

Question 14

how is an AVM managed?

Answer 14

end-vascular ablation (catheter ) glue injection

microsurgery

stereotactic radiotherapy