Subarachnoid Haemorrhage

Question 1

Role of cranial imaging and LP in SAH

Answer 1

CT scanning - show subarachnoid or intraventricular blood in 90% of patients
LP carried out only if CT scan not available or scan is inconclusive
- patient should be alter and orientated without focal signs
SAH diagnosed if the CSF is blood-stained or xanthochromic
Focal angiography may be required if clinical signs suggest SAH, but all other tests are negative

Question 2

Clinical features of SAH

Answer 2

Severe headache of instantaneous onset
- described as the worst headache they have ever experienced
Transient of prolonged LOC
N/V
Drowsiness/coma
Signs of meningism after 3-12 hours
Focal signs from a heamatoma may be present
Papilloedema may be present and accompanied by subhyaloid amd vitreous haemorrhage

Question 3

Pathogenesis of SAH

Answer 3

Cerebral aneurysms are the most frequent cause e.g. AVM or berry aneruysm
No cause can be found in 20% of cases

Question 4

Immediate management of SAH

Answer 4

Regular neurological investigations
Bed rest and fluid replacement
Analgesia - for headache
Nimodipine (calcium channel blocker) - reduces vasospasm
Hypertension control - don’t let become to low as this decreases cerebral perfusion
Transfer to neurosurgical unit

Question 5

Subsequent management of SAH

Answer 5

Berry aneurysm are most common finding at angiography
Surgical management
- endovascular coiling
- surgical clipping
CT angiogram needs to be done to help make the choice
- depends on accessibility and size of aneurysm (coiling preferred where possible
- number of aneurysms

Question 6

Complications of SAH

Answer 6

Rebleeding - most common cause of death, occurs in 20%
Cerebral ischaemia due to vasospasm
- can cause CNS deficit
- most common cause of morbidity
Hydrocephalus due to blockage of arachnoid granulations
- requires a ventricular or lumbar drain
Hyponatraemia
- not managed with fluid restriction
- seek senior help

Question 7

Risk factors for SAH

Answer 7

Smoking
Hypertension
Known aneurysm (Ehler's Danlos, APCKD or coarctation of the aorta)
Family history
Previous aneurysmal SAH 
Alcohol misuse 
Bleeding disorders

Question 8

Grading system for SAH severeity + %mortality

Answer 8

Grade 1 - no signs (0%)
Grade 2 - neck stiffness and CN lesion (11%)
Grade 3 - drowsiness + grade 2 (37%)
Grade 4 - grade 3 + hemiplegia (71%)
Grade 5 - prolonged coma (100%)