A rare case of ruptured anterior cerebral artery infected aneurysm with angioinvasion secondary to disseminated Nocardia otitidiscaviarum: A case report and literature review

BACKGROUND: The cases of ruptured infected aneurysms secondary to disseminated nocardiosis are exceptionally rare. Therefore, there is no guideline for investigation or optimal treatment. CASE DESCRIPTION: A 51-year-old man with immunocompromised status was first presented with pneumonia and cerebral infarction, where the infected aneurysm was ruptured thereafter. Intraoperative findings revealed left anterior cerebral artery thrombosis and occlusion with evidence of angioinvasion along with pus discharge which was later identified with Nocardia otitidiscaviarum. Our case was the first to report on the angioinvasive nature of cerebral nocardiosis, which occurs concurrently with a ruptured infected aneurysm and an unusual presentation that made the diagnosis and treatment challenging. CONCLUSION: Cerebral nocardiosis may cause ruptured infected aneurysms in patients with risk factors, especially for immunocompromised hosts. Furthermore, Nocardia can present with severe cerebral manifestation due to angioinvasion causing cerebral infarction accompanied by a ruptured infected aneurysm.