Sub-arachnoid haemorrhage

Question 1

What is the definition of a sub arachnoid haemorrhage?

Answer 1

Spontaneous arterial bleed into the subarachnoid space

Question 2

How common are sub arachnoid haemorrhage?

Answer 2

Annual incidence of 6 per 100,000

Mean age of presentation is 50 years old

Question 3

What is the pathophysiology of a sub arachnoid haemorrhage?

Answer 3

• Berry aneurysms are most common at the bifurcations/branches of the arteries/Circle of Willis
• Most asymptomatic until they rupture
• Some become symptomatic due to mass effect

Question 4

What are the risk factors/aetiology of sub arachnoid haemorrhage?

Answer 4

• Rupture of berry/saccular aneurysms
• Congenital arteriovenous malformations
• Hypertension
• Atherosclerosis
• Cocaine
• ↑ alcohol
• Trauma
• Genetics
• Family history

Question 5

What are the signs/symptoms of a sub arachnoid haemorrhage?

Answer 5

• Painful 3rd nerve palsy – due to mass effect
• Sudden onset of severe ‘thunderclap’ occipital headache – reaches maximum intensity within minutes
• Nausea/vomiting
• Seizures
• Sometimes loss of consciousness/dizziness
• Neck stiffness – sign of meningeal irritation
• +ve Kernig’s sign – sign of meningeal irritation
• Focal neurological signs
• Papilloedema

Question 6

What diseases present similarly to sub arachnoid haemorrhage?

Answer 6

• Tension headache
• Migraine
• Stroke
• Meningitis

Question 7

What investigations are carried out for a suspected sub arachnoid haemorrhage?

Answer 7

• CT – as soon as possible
• LP – when strong clinical suspicion of sub arachnoid haemorrhage but CT is normal
• ↑ bilirubin/oxyhaemoglobin which leads to a red/brown colouration
• Must be performed at least 12 hours after symptoms
• MR angiogram
• ECG
• Ophthalmoscopy = intraocular haemorrhages

Question 8

What are the surgical treatments for a sub arachnoid haemorrhage?

Answer 8

• Obliteration of the aneurysm by surgical clipping/insertion of a fine wire coil

Question 9

What are the pharmacological treatments for a sub arachnoid haemorrhage?

Answer 9

• Nimodipine (Ca channel blocker)
• Saline fluids – counteract hyponatraemia
• Antihypertensive - prevention

Question 10

What are the non pharmacological treatments for a sub arachnoid haemorrhage?

Answer 10

• Bed rest
• Supportive measures
• Smoking cessation - prevention