What are the causes of proptosis?
Infections, thyriod orbitopathy, tumours, trauma, vascular malformations, orbital pseudotumour.
What are some causes of cavernous sinus thrombosis?
Nasal furuncle (50%), sphenoidal or ethmoidal sinus infection (30%) and dental infections (10%).
What are the clinical findings of cavernous sinus thrombosis?
Headache, ptosis, chemosis and cranial nerve palsies (III, IV, V, VI). Sixth nerve palsy is the most common.
The most obvious finding is left eye proptosis, which must be seen by any radiologist.
Vivid orbital and periorbital swelling.
Enlargement of the left cavernous sinus is seen on pre-contrast T1 coronals.
Post-contrast scans show absent blood flow in the left superior ophthalmic vein due to its thrombosis and dural thickening within left cavernous sinus caused by inflammation.
DWI shows a small acute infarction in the right flocculus.
Sphenoid paranasal sinus mucosa hypertrophy is probably the cause of infection with thrombosis development.
More specifically, the individual series show:
- Axial T2: left proptosis, orbital and periorbital swelling, old pontine lacunar infarcts, right flocculus T2-hyperintensity and sphenoid paranasal sinus mucosa hypertrophy.
- Coronal FLAIR: old pontine infarcts, right flocculus swelling.
- Coronal T1: enlargement of the left cavernous sinus, isointense to white matter.
- Axial T1 C+: thrombed unenchanced left and enlarged right superior ophthalmic veins. Contrast medium absent in the lumen of the left sigmoid sinus and dural thickening within the left cavernous sinus.
- Sagittal MRV: absent blood flow in one of the sigmoid sinuses.
- Coronal T1 C+: dural thickening of the left cavernous sinus.
- Axial DWI: right flocculus acute infarction with bright signal representing diffusion restriction (ADC not shown).