Pediatric Subdural Empyema and Epidural Empyema

Subdural Empyema

  • Etiology:
    — Previously associated with meningitis
    — Now primarily direct intracranial extension from sinusitis or mastoiditis or trauma or iatrogenic
  • Imaging MRI:
    — More apparent on MR than CT
    — Narrow collection with disproportionate mass effect
    — Adjacent cortex slightly thickened (hyperemia)
    — With or without evidence of osteomyelitis of the sinus wall
    — T1WI post contrast: Meningeal and vascular enhancement
    — FLAIR: Hyperintense
    — DWI: Restricted diffusion
  • DDX: Epidural empyema – almost always coexistant
  • Complications: Venous thrombosis, infarct, cerebral edema
  • Treatment: Neurosurgical emergency – craniotomy, if not treated quickly collection will become loculated and infarction or abscess will develop in brain
  • Clinical: Presentations:
    — Acute: Fever, headache, meningeal signs – usually from sinus disease
    — Subacute: Often post-procedural – low fever and headache, no neurologic signs
    — Infancy: Fever, seizures, rapid decline

Epidural Empyema

  • Etiology:
    — Primarily direct intracranial extension from sinusitis or mastoiditis or trauma or iatrogenic
    — Commonly from Streptococcus or Staphylococcus
  • Imaging CT:
    — Hypodense extraaxial collection
  • Imaging MRI:
    — Typically focal or localized extra-dural collection
    — T1WI: Isointense
    — T1WI post contrast: Thick dural enhancement
    — T2WI: Hyperintense
    — DWI: Restricted diffusion
  • DDX: Subdural empyema – almost always coexistant
  • Complications:
  • Treatment: Isolated (rare) epidural empyema not a surgical emergency, clinicians often willing to drain epidural empyema but may fail to drain clinically much more important subdural empyema
  • Clinical: Present with mental status changes, neck pain, fever, seizures, vomiting

Cases of Subdural Empyema and Epidural Empyema

Radiology Cases of Sinusitis with Pott Puffy Tumor with Epidural Empyema

CT of Pott puffy tumor and subdural empyema
Sagittal CT with contrast of the brain shows frontal and left maxillary sinusitis and extensive soft tissue swelling anterior to the forehead (upper left) and destruction of the anterior left frontal bone in the frontal sinus and extensive soft tissue swelling anterior to the left orbit (upper right). Coronal (lower left) and sagittal (lower right) T1 MRI with contrast of the brain shows diffuse meningeal enhancement, subdural empyemas along the falx and both cerebral convexities, and multiple large non-enhancing subgaleal fluid collections in the left scalp.

Radiology Cases of Sinusitis with Subdural Empyema

MRI of sinusitis, meningitis, and subdural empyema
Axial (above left and above middle) and coronal (above right) T1 MRI with contrast of the brain shows opacification and rim enhancement of the left ethmoid and frontal sinuses, diffuse enhancement of the left meninges, and subdural fluid collections along the left convexity and falx posteriorly. Axial diffusion weighted (lower left) and ADC (lower right) images show diffuse restriction in the left frontal sinus and parafalcine subdural fluid collections.