Ruptured right posterior communicating artery, most likely a berry aneurysm!!
Berry aneurysms are thin-walled saccular outpouchings in the vessels of the brain. These outpouchings lack a media layer (unlike other vessels in the brain) & therefore have an increased propensity to rupture! When ruptured, they bleed into the subarachnoid space causing hemorrhage. Subarachnoid haemorrhage presents classically with sudden onset of explosive and severe headache followed by nausea, vomiting, photophobia, and meningism. Often the patient loses consciousness, and the diagnosis is apparent clinically and confirmed by appropriate imaging of the brain or the finding of blood in the CSF. However, on occasions the diagnosis can be difficult to make especially when the history is less clear cut, and the combination of CT and MRI is essential to show the presence of acute haemorrhage, as MRI in isolation can be misleading. When a brain aneurysm has ruptured, it has a high risk of rupturing again and a second rupture carries significant risk of mortality. For these reasons, it is imperative to find the ruptured brain aneurysm as soon as possible with a special test called cerebral angiography that provides a map of the blood vessels in the brain. Once the aneurysm is found, it can be treated 2 different ways, by an open surgical aneurysm clipping or by minimally invasive neuroendovascular aneurysm coiling.
