The headache, lethargy, and neck stiffness suggest subarachnoid hemorrhage secondary to rupture of a mycotic aneurysm. Mycotic or infected arterial aneurysms can develop due to metastatic infection from IE, with septic
embolization and localized vessel wall destruction in the cerebral (or systemic) circulation. Intracerebral mycotic aneurysms can present as an expanding mass with focal neurologic findings or may not be apparent until aneurysm rupture with stroke or subarachnoid hemorrhage. The diagnosis of mycotic cerebral aneurysm can usually be confirmed with computed tomography angiography. Management includes broad-spectrum antibiotics (tailored to blood culture results) and surgical intervention (open or endovascular).