Mycotic aneurysm of the internal carotid artery presenting with multiple cerebral septic emboli.

Mycotic aneurysms of the extracranial carotid artery are uncommon and always warrant surgical treatment to prevent eventual rupture and death. Septic embolization to the brain is an even rarer complication of these aneurysms. We present a case of a 79-year-old male with an extracranial internal carotid artery mycotic aneurysm during Staphylococcus aureus bacteremia. He presented with hemiparesis owing to brain embolism from multiple septic emboli originating from the aneurysm. Multidetector computed tomographic angiography contributed to the diagnosis. Resection of the aneurysm and restoration of arterial supply to the brain by vein graft interpositioning was the therapeutic procedure along with long-term antibiotic treatment. A high index of suspicion is required for the diagnosis of a mycotic carotid aneurysm and aggressive treatment is always needed to prevent lethal complications.