476499
Subarachnoid Haemorrhage
- Incidence
- 8/100,000/yr. Typically 35-65yrs
- 8/100,000/yr. Typically 35-65yrs
- Causes
- Rupture of saccular aneurysms (80%),
AV malformations (15%), no cause
found <15%.
- Risk factors: Smoking, alcohol misuse,
hypertension, bleeding disorders, mycotic
aneurysm post-SBE, possibly lack of oestrogen
(post menopausal), F:M >1:1, FH – close
relatives have 3-5x increased risk
- Berry aneurysms: Common sites: junction of
posterior communicating with internal carotid,
junction of anterior communicating with anterior
cerebral artery, junction of anterior communicating
with bifurcation of middle cerebral artery. 15% are
multiple. Some are hereditary. Associations:
Polycystic kidneys, COA, Ehlers-Danlos syndrome
(hypermobile joints/increased skin elasticity)
- Rupture of saccular aneurysms (80%),
AV malformations (15%), no cause
found <15%.
- Symptoms & Signs
- Symptoms: Sudden (within seconds), devastating,
typically occipital headache. Vomiting, collapse (+/-
seizures), coma. Coma/drowsiness often last for
days. 6% have earlier sentinel headache perhaps
due to small warning leak from offending aneurysm.
Signs: Neck stiffness, Kernigs sign takes 6hrs to
develop, retinal and subhyaloid haemorrhage. Focal
neurology at presentation may suggest site of
aneurysm ie pupil changes indicating CNIII nerve
palsy with a posterior communicating artery
aneurysm or intracerebral haematoma. Later
deficits suggest ischaemia from vasospasm,
rebleeding or hydrocephalus.
- Symptoms: Sudden (within seconds), devastating,
typically occipital headache. Vomiting, collapse (+/-
seizures), coma. Coma/drowsiness often last for
days. 6% have earlier sentinel headache perhaps
due to small warning leak from offending aneurysm.
Signs: Neck stiffness, Kernigs sign takes 6hrs to
develop, retinal and subhyaloid haemorrhage. Focal
neurology at presentation may suggest site of
aneurysm ie pupil changes indicating CNIII nerve
palsy with a posterior communicating artery
aneurysm or intracerebral haematoma. Later
deficits suggest ischaemia from vasospasm,
rebleeding or hydrocephalus.
- Differential Diagnosis
- Meningitis, migraine, intracerebral bleeds, cerebral
venous thrombosis, in 50-60% of those with
‘thunderclap’ headache no cause is found
- Meningitis, migraine, intracerebral bleeds, cerebral
venous thrombosis, in 50-60% of those with
‘thunderclap’ headache no cause is found
- Investigations
- CT – detects >90% within the first 48hrs. Older scanners may
miss more. If CT –ve but strong clinical suspicion do LP >12hrs
after headache onset. In SAH CSF will be bloody early on and
xanthochromic (yellow) after a few hrs supernatant from spun
CSF is looked at photometrically to find breakdown products of
Hb. Finding bilirubin confirms SAH and shows CSF not just a
‘bloody tap’
- CT – detects >90% within the first 48hrs. Older scanners may
miss more. If CT –ve but strong clinical suspicion do LP >12hrs
after headache onset. In SAH CSF will be bloody early on and
xanthochromic (yellow) after a few hrs supernatant from spun
CSF is looked at photometrically to find breakdown products of
Hb. Finding bilirubin confirms SAH and shows CSF not just a
‘bloody tap’
- Management
- Get neurosurgical help in all cases. Immediately if reduced
consciousness, progressive focal deficit or cerebellar
haemotoma is suspected. Bed rest, chart BP, pupils, coma
level. Repeat CT if deteriorating. Re-examine CNS often.
Prevent need for straining with stool softeners.
- Surgical
- Craniotomy and clipping aneuryms can prevent re-bleeds. Best in
those with few/no symptoms. If surgery likely do prompt angiography.
Intraluminal platinum coils are an alternative with less mortality.
Intracranial stents and balloon remodelling used for wide-necked
aneurysms. Microcatheters can now reach previously unreachable
lesions and AV malformations and fistulae may also benefit from this
procedure
- Craniotomy and clipping aneuryms can prevent re-bleeds. Best in
those with few/no symptoms. If surgery likely do prompt angiography.
Intraluminal platinum coils are an alternative with less mortality.
Intracranial stents and balloon remodelling used for wide-necked
aneurysms. Microcatheters can now reach previously unreachable
lesions and AV malformations and fistulae may also benefit from this
procedure
- Medical
- Cautiously control hypertension, analgesia for headache, bed
rest +/- sedation for 4 weeks, keep hydrated (dehydration
worsens vasospasm). Vasospasm – nimodipine (calcium
antagonist) for 3 wks if BP allows
- Cautiously control hypertension, analgesia for headache, bed
rest +/- sedation for 4 weeks, keep hydrated (dehydration
worsens vasospasm). Vasospasm – nimodipine (calcium
antagonist) for 3 wks if BP allows
- Surgical
- Get neurosurgical help in all cases. Immediately if reduced
consciousness, progressive focal deficit or cerebellar
haemotoma is suspected. Bed rest, chart BP, pupils, coma
level. Repeat CT if deteriorating. Re-examine CNS often.
Prevent need for straining with stool softeners.
- Rebleeding is common mode of death and occurs in
30% often in first few days. Vascular spasm follows a
bleed often causing ischaemia +/- permanent CNS
deficit. If this happens surgery is not helpful at time but
may be so later. Most mortality occurs in first month, of
those surviving first month 90% survive a year or more.
- Grade I: no signs: 0% mortality, Grade II: neck stiffness
and CN palsies: 11% mortality, Grade III: drowsiness:
37%, Grade IV: drowsiness with hemiplegia: 71%,
Grade V: prolongued coma: 100%
- Grade I: no signs: 0% mortality, Grade II: neck stiffness
and CN palsies: 11% mortality, Grade III: drowsiness:
37%, Grade IV: drowsiness with hemiplegia: 71%,
Grade V: prolongued coma: 100%
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