Subarachnoid Haemorrhage

Question 1

What is a subarachnoid haemorrhage?

Answer 1

haemorrhage into subarachnoid space

Question 2

What is the most common cause of SAH?

Answer 2

Head injury- traumatic SAH
(absence of trauma is rarer- Spontaneous SAH)

Question 3

Give 4 causes of spontaneous subarachnoid haemorrhage

Answer 3

85%: rupture of a saccular aneurysm at the base of the brain (Circle of Willis- Berry aneurysms)
Arteriovenous malformations
Pituitary apoplexy
Mycotic (infective) aneurysm

Question 4

List 4 conditions associated with saccular aneurysms

Answer 4

Polycystic kidney disease
Ehlers-Danlos syndrome
Coarctation of the aorta
Marfan’s syndrome

Question 5

List 5 risk factors for SAH

Answer 5

HTN
Smoking
Excess alcohol intake
FH
Methamphetamine + Cocaine

Question 6

Describe the epidemiology of subarachnoid haemorrhage

Answer 6

Incidence: 10/100,000
Peak incidence: 50s

Question 7

List 5 symptoms of subarachnoid haemorrhage

Answer 7

Sudden-onset worst headache ever (Hit in the back of the head with baseball bat/ Thunderclap)

Meningeal signs: Photophobia, Neck stiffness, N+V 

Impaired consciousness + GCS
Fever (blood irritating meninges)
Sweating, haemodynamic instability

Question 8

Where may the headache in SAH radiate?

Answer 8

Neck + back

Question 9

What signs may arise in subarachnoid haemorrhage due to mass effect?

Answer 9

Cranial nerve palsies (III, VI)
Altered mental status
Focal neurological deficits
Seizures

Question 10

What may be seen on Fundoscopy in SAH?

Answer 10

Subhyaloid haemorrhage

Question 11

Give 3 signs of raised ICP in SAH

Answer 11

Papilloedema
HTN
Bradycardia

Question 12

What prodromal symptoms may be experienced prior to a SAH? When?

Answer 12

Sudden severe headache
Transient diplopia
30-50% report Sx days-weeks prior

Question 13

What bloods should be taken in SAH?

Answer 13

FBC
U+Es
ESR/CRP
Clotting

Question 14

Once spontaneous subarachnoid haemorrhage is confirmed, what further investigations are necessary?

Answer 14

CT intracranial angiogram:
visualise aneurysm (accumulation of contrast)
detect extravasation of contrast if active bleeding
provides info to plan repair

Question 15

What is the gold standard investigation for cerebral vessel imaging?

Answer 15

Digital subtraction angiography (DSA- catheter angiogram)
Detects small aneurysms

Question 16

What is xanthochromia?

Answer 16

Straw-coloured CSF due to breakdown of RBCs

Question 17

What may be seen on ECG in SAH?

Answer 17

ST elevation

Question 18

What is the firstline investigation in SAH? What may be seen

Answer 18

Non-contrast CT head
Acute blood (hyperdense) typically distributed in the basal cisterns, sulci + in severe cases the ventricular system.

Question 19

If CT head is done within 6h of symptom onset and is normal, what further investigations should be performed?

Answer 19

DONT do LP
Consider alternate dx

Question 20

If a CT head scan done >6h after symptom onset and is normal, what further investigations should be performed?

Answer 20

Lumbar puncture 12h after symptom onset to allow for development of xanthochromia

Question 21

What CSF findings are consistent with SAH?

Answer 21

Xanthochromia (distinguishes true SAH from traumatic tap blood)
Normal/ raised opening pressure

Question 22

What is the initial management of a patient with spontaneous SAH?

Answer 22

A-E, secure airway
Anticoagulant reversal
BP Mx: IV antihypertensives if necessary, if raised ICP consider permissible HTN
ICP Mx: mannitol IV, raise head of bed

Question 23

What surgical interventions are performed in aneurysmal SAH?

Answer 23

Microsurgical Clipping
Endovascular Coiling

Most are now treated with a coil by interventional neuroradiologists, but a minority require a craniotomy + clipping by a neurosurgeon

Question 24

Compare the advantages and disadvantages of coiling and clipping

Answer 24

Coil: minimally invasive, higher risk of incomplete obliteration + recurrent bleeding

Clip: more invasive, higher rate of complete aneurysmal occlusion, lower risk recurrent bleeding

Question 25

Give 3 indications for endovasacular coiling

Answer 25

Poor surgical candidates
Posterior circulation aneurysms
Vasospasm

Question 26

Give 4 indications for microsurgical clipping

Answer 26

Large intracerebral haematoma (e.g. with increased ICP)
Middle cerebral artery aneurysm
Difficult endovascular access
Failed endovascular Tx

Question 27

Describe the procedure of endovascular coiling

Answer 27

Insertion of catheter under fluoroscopic guidance
Placement of metal coils in the aneurysm lumen to interrupt blood flow + induce thrombotic occlusion

Question 28

Describe the procedure of microsurgical clipping

Answer 28

Craniotomy + exposure of aneurysm
Mechanical occlusion of the neck of aneurysm using titanium clips

Question 29

What non-surgical management is required in spontaneous SAH?

Answer 29

Nifedipine PO (prevents vasospasm)
Tx of hydrocephalus (external ventricular drain/ lumbar drainage)
Detect cardiopulmonary complications: CXR, ECG, trop

Question 30

Describe management of traumatic SAH

Answer 30

Supportive
Aim to prevent secondary brain injury

Question 31

List 3 complications of SAH

Answer 31

Vasospasm- can lead to ischaemic stroke
Recurrent bleeding- highest risk in first 12h
Hydrocephalus: acute obstructing or chronic communicating

Question 32

Describe re-bleeding as a complication of SAH

Answer 32

Happens in ~10% of cases + most common in first 12h
If suspected (e.g. sudden worsening of neurological Sx) then a repeat CT should be arranged
a/w a high mortality (up to 70%)

Question 33

Describe management of hydrocephalus post SAH

Answer 33

Temporarily treated with an external ventricular drain (CSF diverted into a bag at the bedside) or, if required, a long-term ventriculoperitoneal shunt

Question 34

Describe management of vasospasm post SAH

Answer 34

Ensure euvolaemia (normal blood volume)
Consider Tx with a vasopressor if Sx persist

Question 35

List 3 predictive factors in SAH

Answer 35

Conscious level on admission
Age
Amount of blood visible on CT head