Subdural empyema

Case contributed by RMH Core Conditions


GCS 8. Dilated pupil. Fever 40.

Patient Data

Age: 30 years
Gender: Male

Left extra-axial collection containing gas. Left inferior frontal lobe hypodensity. Significant intracranial mass effect, with 9 mm of rightward midline shift, suprasellar cistern, and effacement and evidence of right ventricular entrapment. Air-fluid levels in the frontal sinuses, and partial opacification of the ethmoid air cells.  


Linear enhancement along the left frontal lobe is probably dural in origin. No CT evidence of a cerebral abscess.

Case Discussion

This extra-axial collection has characteristics of a subdural empyema, likely secondary to acute sinusitis. Parenchymal hypodensity in the left inferior frontal lobe adjacent to the collection without enhancing focus likely represents cerebritis. 

The patient proceeded to urgent neurosurgery, and pus was drained from the sinuses and subdural space. 

Microscopy and culture


  • Leukocytes ++
  • Gram positive cocci ++
  • Gram negative bacilli ++


Mixed anaerobes including:

  1. Prevotella oris +
  2. Slackia exigua +
  3. Fusobacterium nucleatum ++
  4. Parvimonas micra ++

Sinusitis is the most common cause of intracranial subdural empyema with anaerobic organisms common. 

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Case information

rID: 47834
Published: 9th Sep 2016
Last edited: 20th Dec 2019
Inclusion in quiz mode: Included

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