- Early mortality 25-50%, 50% morbidity; usually 30-69 years old,
moderte female prepoderance, distribution (internal carotid - 35-49%,
ACA complex - 30%), 20% have multiple aneurysms, average size of
ruptured aneurysm is 8-9 mm, if < 5 mm rupture is unlikely.
Risk factors - Increased arterial flow
(agenesis or ligation of ICA, feeding arteries to AVMs, aortic coarction,
Circle or Willis variations), arterial wall defects (fibromuscular
dysplasia, Ehlers-Danlos, Marfan's syndrome, moyamoya disease),
hypertension (coarction, polycystic kidney disease), smoking, alcohol
abuse, pregnancy, familial (more MCA distribution, younger patients
with smaller ruptures).
Causes - Traumatic, spontaneous (primary
- aneurysms 70-75%, AVM 5-10%, unknown 10-20%, secondary [hematoma
extension, hypertension bleed, amyloid angiopathy, neoplasms, angiopathy,
Pediatrics - Same causes, aneurysms
are less common (50%) and AVMs are more common (25%) aneurysms are
more often traumatic - infectious - giant - or located posterioly,
associated with congenital disorders (aortic stenosis), more males.
Clinical Sudden headache, nausea, vomiting, common initial LOC,
meningismus, photophobia, focal, neurological defect (cranial nerve
damage, focal clot or intraparenchymal hemorrhage), altered mental
Differential Diagnosis - Ischemic stroke
(atherosclerosis, embolism, arteritis, sickle cell, polycyhtemia...),
intracerebral hemorrhage (spontaneous, AVM, cavernous angiomas).
migraine, tension headache, sinusitis, viral meningitis, encephalitis.
Diagnosis - 90%+ sensitive if performed
within 24 hours, LP with negative CT to check for xanthochromia
(present 12 hours and resolves within 3 weeks); Perform angiography
with no mass or mass with good clinical condition; take to OR with
mass and deteriorating clinical condition.
Hunt Hess Class. - Grade 1 -
no symptoms / minimal headache; Grade 2 - moderate to severe
headache, nuchal rigidity, no neuro deficit; Grade 3 - drowsy,
confused, mild neuro deficit; Grade 4 - stupor hemiparesis,
? decerebrate rigidity, vegetative disturbances; Grade 5
- deep coma, moribund, decerebrate rigidity.
Complications - Increased ICP, vasoconstriction
-vasospasm (AMS, focal neuro deficit, cerebral infarction), hydrocephalus,
cerebral edema, mass effect (clot, hematoma, edema), neuro deficits,
seizures (10-25%, increased risk - hematoma - infarction - AVM -
H/O seizure), intraventricular hemorrhage, cerebral ischemia, hypertension,
ECG, abnormalitites, neurogenic pulmonary edema, electrolyte abnormality
(SIADH, DI), rebleeding.
Ventricular Drainage - Grade III -
V, increased ICP, thick subarachnoid clot
Sudden Deterioration - Rebleeding,
arrhythmias, seizure, hydrocephalus, increasing ICP
Management - (Obtain neurosurgery consult
STAT) - ABCs, BP control, prevent or treat vasospasm/hydrocephalus...,
hydration, sedation, pain control, ? seizure prophylaxis, elevate
HOB, bed rest, stool softeners, ? ventricular drainage, surgery,