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What is A patient with suspected subarachnoid haemorrhage presents with blood isolated in the fouh ventricle on a CT scan. Aneurysmal rupture is likely to have resulted from and explain in detail?
*Saccular aneurysm at size of >7mm and at top of basilar aery and at origin of posterior communicating aery are at greater risk of rupture . Ref Harrison20th edition pg 2445