P-OT023. Intracranial subdural empyema mimicking acute on chronic subdural hematoma: a case report

Abstract

Introduction. Intracranial subdural empyema is a rare localized intracranial infection that forms between dura and arachnoid membrane of the meninges. Its unspecific clinical presentations as well as neuroimaging findings that might resemble subdural hematoma make the definitive diagnosis of subdural empyema difficult. This report aims to highlight the importance of making a differential diagnosis of subdural empyema in a suspected case of subdural hematoma. Results. A 71 years old male presented with acute mild to moderate intermittent headache that was followed by sudden difficulty in word findings and right limbs weakness. No history of fever, trauma, seizure, or prior history of ear, nose, throat, tooth infections, and intracranial surgical procedure. Increased white blood cells count was not found despite the increased neutrophil to lymphocyte ratio as well as C-reactive protein. Non-contrast head CT-scan showed crescentic hyperdense lesion within a wider hypodense lesion in the left frontotemporoparietal region, characterizing acute on chronic subdural hematoma. During burr hole drainage, pus was found, consistent with subdural empyema. An intralesion antibiotic treatment was given after complete removal of the pus. Conclusion. Intracranial subdural hematoma and subdural empyema with the involvement of neurological deficits are emergency conditions. However, it is difficult to differentiate these two conditions even after the examinations of clinical, laboratory, and neuroimaging with non- contrast head CT-scan, particularly without the triad of subdural empyema: fever, headache, vomiting. Our case showed that even without noticeable port d’entry, intracranial subdural empyema could be formed.