ABSTRACT
A sudden dramatic elevation of intracranial pressure (ICP) accounts for the classic presentation of acute aneurysm rupture-the instantaneous onset of a severe headache often described by patients as “the worst headache of my life” ( 1 ). Headache frequently presents during physical exertion and is often associated with nausea and vomiting. Syncope (mainly due to increased ICP) is seen in about half of cases and is usually followed by a gradual improvement in the level of consciousness. Focal neurologic signs appear in only 10% to 15% of cases and typically represent mass effect from a giant aneurysm (e.g., an enlarging posterior communicating artery aneurysm pressing upon the third cranial nerve), intraparenchymal hemorrhage, subdural hematoma, or a large localized subarachnoid clot. There may be a report of a seizure, but it is often unclear as to whether these episodes are true epileptic events or abnormal posturing. Up to 20% of patients with subarachnoid hemorrhage (SAH) may develop intraocular hemorrhages ( 2 ).
