Subarachnoid Haemorrhage

Question 1

Define

Answer 1

DEFINITION: arterial haemorrhage into the subarachnoid space

Onset: Rapid, within seconds

Question 2

Causes

Answer 2

85% - rupture of a saccular aneurysm at the base of the brain (Berry aneurysms)

10% - perimesencephalic haemorrhage

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

Question 3

Risk factors

Answer 3

Hypertension

Smoking

Excess alcohol intake

Saccular aneurysms are associated with:

• Polycystic kidney disease
• Marfan’s syndrome
• Ehlers-Danlos syndrome

Question 4

Epidemiology

Answer 4

Incidence: 10/100,000

Peak incidence: 40s

Question 5

Symptoms

Answer 5

Sudden-onset worst headache ever

Nausea/vomiting

Neck stiffness

Photophobia

Reduced level of consciousness

Question 6

Signs

Answer 6

Meningism

• Neck stiffness
• Kernig’s sign
• Pyrexia

GCS - check for deterioration

Signs of raised ICP - papilloedema, IV or III nerve palsies, hypertension, bradycardia

Focal neurological signs (e.g. cranial nerve palsies)

Question 7

Investigations

Answer 7

Bloods

• FBC
• U&Es
• ESR/CRP
• Clotting

CT Scan

• Hyperdense areas in the basal regions of the skull (due to blood)

Angiography - detect source of bleeding

Lumbar Puncture

• Increased opening pressure
• Increased red cells
• Xanthochromia - straw-coloured CSF due to breakdown of red blood cells