Most aneurysms that rupture are smaller than 10 mm; giant aneurysms exceed 25 mm. Posterior circulation location, size over 7 mm, and prior aneurysmal rupture are the strongest rupture predictors. Surgical indications include aneurysm larger than 5 mm, Circle of Willis location, and age under 70 in good health. Follow-up with annual CTA or MRA, spacing out intervals if stable.

Moyamoya causes both ischemic (predominant in adults) and hemorrhagic (predominant in children) strokes.Extracranial-intracranial bypass surgery improves cerebral perfusion in Moyamoya.Unruptured intracranial aneurysms prevalence: 3-5% of the general population.Aneurysm risk factors: female sex, hypertension, smoking, cocaine use, connective tissue disorders, family history.Associated conditions: polycystic kidney disease, coarctation of the aorta, neurofibromatosis, Marfan syndrome, Ehlers-Danlos Type 4.Most ruptured aneurysms are smaller than 10 mm; giant aneurysms exceed 25 mm.Rupture predictors: size over 7 mm, posterior circulation location, prior aneurysmal rupture.Posterior circulation aneurysms carry higher rupture risk than anterior circulation.Additional rupture risk factors: family history of aneurysms, polycystic kidney disease.Surgical indications: aneurysm over 5 mm, Circle of Willis location, age under 70 in good health.Follow-up: annual CTA or MRA, with intervals extended if stable.