What are the 2 main causes of subarachnoid hemorrhage?
1º ruptured berry aneurysm - 85% 2º non-aneurysmal (perimesencepalic) haemorrhage - 10%
Which is the most frequent location of berry aneurysms?
the majority of berry aneurysms occurring round the circle of Willis(~65%), or in the sylvian fissure (~30%)
Which is the differential diagnosis of Aneurysmal subarachnoid hemorrhage?
non aneurysmal SAH, pseudo-subarachnoid haemorrhage, bacterial meningitis, tuberculous meningitis, granulomatous meningitis, meningeal melanosis, contrast in CSF
What is the typical patient with HSA?
Middle-aged women patient with "worst headache of my life"
Hyperdense subarachnoid space, focused primarily on the right Sylvian fissure, right frontal sulci, basal cisterns with hyperdense expansion in locating the right MCA, suggesting ruptured right MCA aneurysm.
Produces moderate mass effect on the Sylvian fissure extending it, with slight compression of the anterior horn of the right lateral ventricle, minimal subfalcial herniation left, moderate left descending transtentorial herniation.
Also observed a small amount of material blade in the third and fourth ventricles without associated ventricular dilatation.
No alterations were identified in the brain parenchyma density suggesting ischemic areas.
These findings are consistent with acute SAH secondary to a ruptured aneurysm of the right middle cerebral artery.