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Subdural Empyema

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Subdural Empyema, Subdural Abscess

  • See Also
  1. Brain Abscess
  2. Epidural Abscess
  3. Intracranial Mass
  4. Bacterial Meningitis
  5. Bacterial Meningitis Management
  6. Neisseria Meningitidis
  7. Viral Meningitis
  8. Aseptic Meningitis
  9. Encephalitis
  10. Brain Abscess
  11. Viral Meningitis
  12. Aseptic Meningitis
  13. Encephalitis
  • Definitions
  1. Subdural Abscess (Subdural Empyema)
    1. Purulent collection between the Dura Mater and the acrachnoid membrane
    2. Most commonly a complication of Sinusitis or Mastoiditis
  • Epidemiology
  1. Subdural Empyema is most common in young males
  • Pathophysiology
  1. Spread of infection from the sinuses directly into the subdural space (via bone haversian canals)
  2. Children are more prone to Subdural Empyema due to highly vascular sinuses
  3. Infections spread more rapidly through the subdural space than through the epidural or intracranial space
  • Risk Factors
  1. Prior Head Trauma
  2. Neurosurgery history
  • Causes
  • Source
  1. See Brain Abscess
  2. Subdural Abscess (Subdural Empyema) is a spread of Sinusitis or Mastoiditis in 60-90% of cases
    1. Mastoiditis (due to Chronic Otitis Media)
    2. Sinusitis (most commonly frontal, but also ethmoid, sphenoid and Maxillary)
    3. Dental Infection
  • Causes
  • Organisms
  1. See Brain Abscess
  2. Often polymicrobial infections
  3. Anaerobic Bacteria
  4. Aerobic streptococci
  5. Streptococcus Pneumoniae
  6. Staphylococci
  7. Staphylococcus epidermidis
  8. Haemophilus Influenzae
  9. Gram Negative Bacteria
  • Symptoms
  1. Recent Upper Respiratory Infection
  2. Severe Headache
    1. Typically unilateral in the region of abscess
  3. Photophobia
  4. Vomiting
  5. Seizures
  6. Fever
  7. Confusion
  • Signs
  1. Fever
  2. Focal neurologic deficit
  3. Seizure
  4. Altered Level of Consciousness
    1. Associated with significant brain edema and with worse prognosis
  5. Comorbid Orbital Cellulitis may also be present
  • Imaging
  1. CT Head with contrast OR
  2. MRI Brain with gadolinium (preferred)
  • Differential Diagnosis
  1. See Brain Abscess
  2. See Intracranial Mass
  3. Bacterial Meningitis
  4. Other Brain Abscess (including Epidural Abscess)
  5. Cerebral Venous Thrombosis
  • Labs
  1. Complete Blood Count
  2. C-Reactive Protein
  3. Lumbar Puncture
    1. Indicated if Meningitis is suspected, but may be non-diagnostic in Subdural Empyema
    2. Contraindicated in focal symptoms/signs, CNS mass, Increased Intracranial Pressure (risk of Herniation)
    3. Obtain CNS imaging prior to Lumbar Puncture
  • Management
  1. See Brain Abscess
  2. Urgent Consultations (neurosurgery, infectious disease, otolaryngology)
  3. Initial Empiric Antibiotics
    1. Overall Antibiotic course of 4-6 weeks is typical
    2. Cefotaxime 2 g IV q4 hours OR Ceftriaxone 2 g IV every 12 hours (or Pen G 3-4 MU q4h) AND
    3. Metronidazole 7.5 mg/kg every 6 hours AND
    4. Vancomycin for suspected Staphylococcus aureus
  4. Neurosurgical drainage
    1. Early intervention within first 72 hours may have greatest effect on outcome
    2. Craniectomy or burr hole drainage are most common
    3. Nonsurgical approach considered if clinically stable, <1 cm abscess and no midline shift
  5. Other adjuntive measures to consider (consult local expert opinion)
    1. Corticosteroids for brain edema
    2. Endoscopic Sinus Surgery may be considered
      1. Direct extension from sinus into subdural space through bony defect
  • Prognosis
  1. Mortality as high as 35% in Subdural Empyema
  • Complications
  1. Associated with high morbidity and mortality
  2. Cognitive difficulties
  3. Hemiparesis
  4. Expressive Aphasia
  • References
  1. (2016) Sanford Guide, accessed 4/9/2016
  2. Marcom (2023) Crit Dec Emerg Med 37(7): 12-4
  3. Southwick in Calderwood (2016) UpToDate, accessed 4/9/2016
  4. Brouwer (2014) N Engl J Med 371:447 [PubMed]