Cavernous sinus thrombosis

• Cavernous sinuses:

  • Large vein at the base of the skull, behind the eyes - drains blood from the face via the internal jugular vein
  • numerous important structures pass through - internal carotid artery and cranial nerves III, IV, V and VI
• Usually caused by an infection:

  • Infection leads to formation of blood clot within cavernous sinus
  • Often arises via contiguous spread from nearby infection - facial, dental, or nasal sinus infection
  • Most common pathogen is Staphylococcus aureus
• Risk factors:

  • Immunosuppression
  • Thrombophilia
  • Obesity
  • Severe dehydration
• Complications:

  • Cavernous system is valveless and communicates with dural sinuses and cerebral veins = meningitis or brain abscess
  • Spready via jugular vein to pulmonary circulation = septic emboli, pulmonary abscess, pneumonia
  • Carotid artery narrowing = stroke
  • Ischaemia/direct infectious spread to pituitary gland = hypopituitarism
• Symptoms:

  • Exophthalmos
  • Pain in the eye and forehead - ophthalmic branch of CNV
  • Fevers and rigors
  • Cranial III, IV, VI nerve palsies - diplopia, limited abduction, non-reactive pupil, proptosis
  • Oedema of the periorbital structures and forehead due to blockage of venous drainage
  • Symptoms usually unilateral
• Diagnosis:

  • CT/MRI
  • +/- lumbar puncture
• Management:

  • IV broad spectrum antibiotics until sensitivities known
  • Sinus drainage