Epidural abscess

Case contributed by Assoc Prof Frank Gaillard


History of IVDU. Paraplegia.

Patient Data

Age: 45 years

Extensive peripherally enhancing epidural collection is noted posterior to the theca from L5 up to L2. This results in thecal sac compression with severe compression of the cauda equina.

At L4/5 there facet joint effusions with adjacent bone marrow edema particularly affecting the articular processes and pedicles of L4. This is associated with lower lumbar psoas and erector spinae muscular edema (worse on the right) containing multiple small peripherally enhancing fluid collections.


Bilateral L4/5 facet joint septic arthritis (right greater than left) - presumably communicating across the retrodural space of Okada - with associated epidural and muscular abscesses. 


A further peripherally enhancing epidural collection is seen anterior to the theca, ascending from the lumbar region up to T1/2. This results in thecal sac compression maximal at T2/3 to T4/5 causing distortion of the cord and T2 signal abnormality 

The patient went on to have multilevel laminectomy (thoracic and lumbar) and drainage of the collections. 


Culture = Staphylococcus aureus +

Case Discussion

This case illustrates a number of important principles:

  • facet joint septic arthritis can lead to extensive epidural abscess
  • facet joints can communicate across the midline via the retrodural space of Okada 
  • if there is any suspicion that the very top/bottom of the collection has not been imaged, the entire spine should be imaged as epidural collections can be extensive and irregular in size
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Case information

rID: 46198
Published: 27th Jul 2016
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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