Acute subdural hematoma caused by rupture of a mycotic aneurysm due to meningitis associated with infectious endocarditis: comparison of autopsy findings with postmortem computed tomography

Forensic pathologists often encounter cases of acute subdural hematoma (SDH) due to trauma, whereas those attributable to endogenous causes are rare. Here, we report a case of the latter type in a 42-year-old man who was found dead at home after several months of fever and malaise. Postmortem computed tomography (PMCT) and autopsy were undertaken to clarify the cause of death. PMCT images revealed a fatal SDH and a localized hyper-density area in the right parietal lobe; macroscopic and microscopic examinations revealed SDH due to rupture of a mycotic aneurysm (MA) associated with meningitis. The PMCT images also indicated thickening and calcification of the mitral valve, while autopsy demonstrated infective endocarditis (IE). In addition, PMCT demonstrated a low-density area in the spleen, which was shown to be a splenic abscess at autopsy. PMCT also demonstrated tooth cavities. Based on the findings of autopsy, the cause of death was considered to be SDH due to rupture of the MA resulting from meningitis with IE and splenic abscess. Although PMCT was unable to clarify the significance of any individual feature, a retrospective review of the PMCT images might have suggested IE, bacteremia, or ruptured MA leading to SDH. This case suggests that, instead of interpreting individual features demonstrated on PMCT images, integrated interpretation of overall PMCT findings might provide clues for identifying causes of death, despite the fact that PMCT lacks diagnostic accuracy for infectious diseases such as IE and meningitis.