Subarachnoid Haemorrhage

Question 1

Define:

Answer 1

Arterial haemorrhage into the subarachnoid space

Question 2

Aetiology:

Answer 2

85% due to rupture of a saccular aneurysm at the base of the brain (berry aneurysm)

10% - perimesencephalic haemorrhage

5% - arteriovenous malformations, bleeding diathesis, vertebral artery dissection

No cause found in <15%

Question 3

Risk factors:

Answer 3

Excessive alcohol consumption
Smoking
Hypertension
Bleeding disorders

Saccular aneurysms are associated with:

• Marfan’s
• Ehler’s Danlos
• Polycystic kidney disease
• Coarctation of the aorta

Question 4

Symptoms:

Answer 4

SUDDEN ONSET WORSE EVER HEADACHES - described as a thunderclap headache

Nausea and vomiting

Seizures

Neck stiffness

Photophobia

Reduced level of consciousness

Question 5

Signs:

Answer 5

Meningism:

• Neck stiffness
• Kernig’s +ve
• Pyrexia

GCS - check for deterioration

Raised ICP signs = papilloedema, Iv and III nerve palsy, HTN, bradycardia

Focal neuro signs = cranial nerve palsies

Question 6

Investigations:

Answer 6

Bloods:

• FBC
• U+Es
• ESR/CRP
• Clotting

CT will detect 90% of SAH in the first 48 hrs

angiography to find the location

LP if the CT is negative and there is no contraindications 12 hours post headache:
First will be bloody CSF –> xanthochromic (straw-like colour due to break down of RBC)
Also an increase in opening pressure