Subdural empyema

Case contributed by RMH Core Conditions


GCS 11-12 with "absence" seizures. Two months post excision of a meningioma.

Patient Data

Age: 72
Gender: Male

Extra-axial collection related to the previous left sided craniotomy is again demonstrated, with a fluid fluid level seen posteriorly on some images suggesting an acute on chronic subdural.

More worrying, here's a locule of what is thought to be is gas seen superiorly which was not evident on previous imaging and raises the possibility of this representing an evolving subdural empyema. Appearances are otherwise unchanged, or encephalomalacia involving the superior aspect of the left frontal lobe in keeping with the previous surgery.

No hydrocephalus. No midline shift. No infarct or intraparenchymal hemorrhage.


The surgical bed and extraaxial collection demonstrates peripheral enhancement, extending into sulci. Two gas locules are demonstrated which were not evident on on the previous CT.


Although a least a proportion of the enhancement demonstrated could be post-operative, increasing size and density of the fluid collection, and enlargement of the extra-axial collection and development of new gas locules is suspicious for an empyema.

Case Discussion

The patient proceeded to theater and a subdural empyema was confirmed. 

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