Hi there. This is a medical emergency since the posterior intracerebral aneurysm could have ruptured. Most intracranial aneurysms do not show any symptoms until rupture causing bleeding. Small ones maintain their size and show no symptoms. Larger ones can cause pressure on nerves and adjoining tissues. Signs of unruptured aneurysm include headaches, double vision, loss of vision, eye and neck pain, warning headaches caused by leakage of blood into the brain prior to its rupture. Symptoms of a ruptured aneurysm are sudden severe headache, lethargy, confusion and stupor, seizures, sudden mood swings, dysarthria, ptosis, movement disorders like ataxia and even death. You need to consult a neurologist immediately for an emergency evaluation with angiography, MRI, CT and CSF analysis. Emergency clipping or coiling would be warranted if it has not ruptured already. Hope this helps. Take care.