Subarachnoid Haemorrhage

Question 1

What condition is being described:

Bleeding into the space between the arachnoid and pia meninges.

Answer 1

Subarachnoid haemorrhage

Question 2

What are the usual causes of subarachnoid haemorrhage?

Answer 2

Berry (saccular) aneurysm rupture (80%)

Arteriovenous malformations (15%)

Question 3

What age group is most likely to be affected by subarachnoid haemorrhage?

Answer 3

35 - 65 yo

Question 4

What are the risk factors associated with subarachnoid haemorrhage?

Answer 4

Smoking
HTN
EtOH
Bleeding diathesis
Mycotic aneurysms
Family Hx (close relatives 3-5x risk)

Question 5

Where do berry aneurysms typical occur?

Answer 5

Junction of posterior communicating artery and the internal carotid.

Junction of the anterior communicating artery and the anterior cerebral artery.

Bifurcation of the middle cerebral artery.

Question 6

What conditions are associated with Berry Aneurysms?

Answer 6

Adult polycystic kidneys

Ehlers-Danlos

Question 7

What are the symptoms of a subarachnoid haemorrhage?

Answer 7

Sudden, severe occipital headache

Collapse

Meningism (neck stiffness, nausea/vom, photophobia)

Seizures

Drowsiness/reduced GCS

Question 8

What signs might be seen in a patient with subarachnoid haemorrhage?

Answer 8

Kernig’s (+ve when the thigh is flexed at the hip and knee at 90deg. and subsequent knee extension is painful and leads to resistance)

Retinal or subhyaloid haemorrhage

Focal neuro deficits

Question 9

What is a sentinel headache?

Answer 9

~6% of patients experience a sentinel headache from a small warning bleed that precedes the rupture of an aneurysm.

Question 10

What are the differentials associated with thunderclap headache?

Answer 10

Subarachnoid haemorrhage (25%) must be ruled out early.

50-60% no cause found

Remaining: meningitis, intracerebral bleeds, cortical vein thrombosis

Question 11

How would you investigate a thunderclap headache?

Answer 11

CT: detects >90% of subarachnoid haemorrhages

LP >12 hours after headache onset
- xanthochromia due to breakdown of bilirubin

Question 12

How do you manage subarachnoid haemorrhage?

Answer 12

Early referral to ICU.

Frequent neuro obs (pupils, GCS, BP)

Maintain cerebral perfusion pressure, keep systolic BP up but balance risk of further stroke.

Nimodipine to reduce cerebral vasospasm.

Surgical: coiling or clipping.

Question 13

What are the complications of subarachnoid haemorrhage?

Answer 13

Rebleeding

Cerebral ischaemia
- due to vasospasm

Hydrocephalus
- due to blockage of arachnoid granulations

Hyponatraemia