Cavernous Sinus Thrombosis/Thrombophlebitis

KEY FACTS

Terminology

• Cavernous sinus (CS)

• Blood clot in CS

Imaging

• CT

  • Bone CT

    • –

      Look for sinus infection, erosive changes

  • CECT

    • –

      Nonenhancing filling defects (clot) inside enhancing dural walls of cavernous sinus (CS)

    • –

      CS margins convex (not flat/concave)

  • CTA/CTV

    • –

      Filling defects in 1 or both CSs

• MR

  • T1WI

    • –

      Convex, enlarged CS (isointense to gray matter)

    • –

      Orbits: ± “dirty fat,” enlarged EOMs, proptosis

  • T2WI

    • –

      Clot heterogeneously hypointense

    • –

      Look for absent carotid “flow void”

  • T2*: Thrombus “blooms”

  • DWI

    • –

      Acute clot, sinusitis may restrict

  • T1 C+: Dura enhances; clot doesn't

    • –

      Clot heterogeneous; ± absent carotid “flow void”

Top Differential Diagnoses

• Neoplasm (meningioma, schwannoma, lymphoma)

• Carotid-cavernous fistula

• Inflammatory pseudotumor (IgG4-related disease, sarcoid)

Clinical Issues

• Headache early

• Orbital/sinus pain, edema, chemosis

• Ptosis, ophthalmoplegia, visual loss

• Cranial neuropathy (typically V1 &/or V2)

• Prognosis

  • Spreads via communicating veins to contralateral CS, eye

  • Untreated CS thrombophlebitis can be fatal

Diagnostic Checklist

• If initial CT negative and clinical suspicion high, CTA/CTV or MR/MRV

TERMINOLOGY