• 5%
of strokes
• 50% mortality
• 10-15% die before reaching hospital
• 50% of patients are less than 55years old
• 85%
are aneurysmal
• 10% non-aneurysmal perimesencephalic
• 5% rare causes
o Tumours
o Inflammatory conditions
o Dissection
o Amyloid
o Arterial malformations/fistula
• Straining/physical activity is reported prior to 20% of ruptures
• Sudden
headache – onset with seconds (75%)
• Often severe but sudden onset is more specific
• Lateralized in 30%
• Vomiting can occur, non-specific
• Seizures – 1in 14 at onset
• 2/3 have decreased consciousness, 50% of which are in a coma
• Neck stiffness common, takes 3-12hours to develop
• Intraoccular haemorrhages – occur in 1 in 7. Due to sustained increase in CSF pressure obstructing central retinal vein.
o May cause visual disturbances/blobs in vision
• Third nerve palsy
• Other focal neurology can occur to infarction.
• Severe hypertension can occur
• Cardiac arrest in 3%
• Re-bleeding
o 15% risk in first few hours
o 40% risk over first 4 weeks
o Significantly worse prognosis, 80% die or disabled
• Delayed brain ischaemia
o Peak onset 5-14days
• Hydrocephalus
o Gradual reduction in consciousness
o Downward deviation of the eyes and small unreactive pupils
• Late
re-bleeding ~0.7% between 1month and 1year
• Epilepsy
o ~8% by 1 year, ~12% by 5 years (Neurology 2015)
• Anosmia in 30%
• Cognitive deficits common
• Psychosocial dysfunction 60% reported changes in personality
• Only 25% recover fully
• 95% will show extravasated blood on first day
• Less on subsequent days
• False positives can occur with diffuse brain swelling due to blood in congested subarachnoid vessels .
• Probably similar sensitivity to CT initially
• Better sensitivity than CT after a few days
• Picks up an additional 3% if negative CT
• Wait 6-12hours after headache onset (sensitivity increases with time up to 12 hours)
• Measure pressure (to exclude other diagnoses)
• If
CSF is spun down and supernatant yellow – this is indicative of bililrubin and
• Formal testing for bilirubin usually done – xanthochromic index
Angiography
• Catheter angiography is gold standard
o Higher risks: 1.8% ischaemic complications, 1-2% aneurysm rerupture
• CT angiography
o 95% sensitivity
o Safer and quick
•
o Good sensitivity but often impractical.
• Evacuation or hemicraniotomy to allow cerebral expansion
• Surgical clipping
o ARR of poor outcome 10%
o RRR of poor outcome 19%
• Endovascular coiling
o ISAT trial showed RRR of 24% and ARR of 7% compared with surgery.
• Calcium channel antagonists
• RRR 18%, ARR 5.1%
• Nimodipine best studied
o 60mg PO Q4h for 3weeks
o IV may be more harm than good
• Magnesium sulphate may be useful
• Maintain intravascular volume (no evidence)
• Lumbar puncture can improve consciousness
• Need to determine if site of obstruction in the subarachnoid space or in the ventricular system.
• Catheter insertion through burr hole.
• Incidental
aneurysm
o Need to consider many risk factors to make informed decision
o Age, Size of lesion, Family history, Location
•
• Second
aneurysms in patients who have had
o Higher risk of rupture
o Higher psychological burden
o Coiling usually offered
• Screening
o
First degree relatives have 5-12x risk of
o Chance of finding lesion is 1.7x general population
o Should screen:
o
People with >1first degree relative with
o ADPKD patients >20yrs old
o
Identical twins if one has
o After initial screen may be benefit in 5 yearly screening
o
No need to screen after an initial episode of
Non-aneurysmal
SAH
• Large single centre series (Stroke 2011;42:3055) of all SAH:
o 17% were non-aneurysmal
o 3% were convexity, non aneurysmal SAH
• Blood
confined to cisterns around midbrain – basal cisterns, quadrigeminal cistern
• Some sedimentation of blood can occur but no frank extension of haemorrhage
• Headache usually slower onset, less change in mental state.
• Angiogram negative
• Probably caused by rupture of vein in prepontine or interpeduncular cistern
• Low risk of re-bleed
• Good prognosis and normal life expectancy
• Minimal data, two major cases series
o Stroke 2011 – 25 cases
o Neurology 2010
Causes identified (in order of frequency):
• Cerebral amyloid angiopathy (especially >60years)
• RCVS
• PRES
• Post CEA hyperperfusion
• Dural sinus thrombosis
• Amphetamine use
• Cerebral vasculitis
• Infective endocarditis
• ITP/anticoagulation etc.
• Moyamoya
Mimics on imaging
• Thrombosed cortical vessel
• Cluster of micobleeds
• Calcification
• Haemorrhagic transformation of infarct
• Headache (~40%)
• Transient sensory/motor symptoms
o Often observed to spread over several minutes
o Often occur recurrently
o ?Seizures vs cortical spreading depression – no epileptiform changes indentified in cases to date - ?therefore more likely cortical depression
• Seizures
o Frequency depends on series (Stroke 2011 - ~ 20%, Neurology 2010 – none)
• Variable depending on series
• Many cases of iscahemic stroke/ICH etc. on follow-up - ?a marker of vascular disease