Cavernous sinus thrombosis
Cavernous sinus thrombosis (CST) is a rare condition, most commonly infectious in nature, and the diagnosis on imaging is not always straightforward. It has high mortality and morbidity rates.
CST is rare with ~4.5 cases per 1,000,000 per year 5. It is the least common dural venous sinus thrombosis, accounting for <1.5% of cases 4.
A headache is the most common symptoms (85%. Focal neurological symptoms and/or seizures may also occur 5. Isolated CN III palsy is thought to be an early manifestation.
Orbital signs can include:
- chemosis and peri-orbital swelling
- sinus compression, e.g. trauma, tumour
- procoagulable conditions, e.g. Protein C/S deficiency, OCP use, malignancy
- idiopathic (25%) 5
CST is a clinical diagnosis, however, MRI with contrast is the modality of choice to confirm its presence and to differentiate it from alternatives such as orbital cellulitis, which may have a similar clinical presentation.
- non-contrast: high-density thrombus in affected cavernous sinus (seen in only 25%) 5
- contrast-enhanced: distended cavernous sinus with a non fat density filling defect 4
T1 and T2 5
- absent flow void
- signal characteristics vary depending on the age of the thrombus but will be abnormal
- contrast-enhancement or lack of is not a reliable indicator as organising thrombus can enhance
- diagnosis can generally be made on venography
Treatment and prognosis
The mortality rate of CST is up to 30% with significant morbidity (e.g. blindness, cranial nerve palsy) in survivors not uncommon 6.
- 1. Absoud M, Hikmet F, Dey P et-al. Bilateral cavernous sinus thrombosis complicating sinusitis. J R Soc Med. 2006;99 (9): 474-6. doi:10.1258/jrsm.99.9.474 - Free text at pubmed - Pubmed citation
- 2. Razek AA, Castillo M. Imaging lesions of the cavernous sinus. AJNR Am J Neuroradiol. 2009;30 (3): 444-52. doi:10.3174/ajnr.A1398 - Pubmed citation
- 3. Lee JH, Lee HK, Park JK et-al. Cavernous sinus syndrome: clinical features and differential diagnosis with MR imaging. AJR Am J Roentgenol. 2003;181 (2): 583-90. doi:10.2214/ajr.181.2.1810583 - Pubmed citation
- 4. Rodallec MH, Krainik A, Feydy A et-al. Cerebral venous thrombosis and multidetector CT angiography: tips and tricks. Radiographics. 2006;26 Suppl 1 (suppl_1): S5-18. doi:10.1148/rg.26si065505 - Pubmed citation
- 5. Leach J, Fortuna R, Jones B et-al. Imaging of Cerebral Venous Thrombosis: Current Techniques, Spectrum of Findings, and Diagnostic Pitfalls1. Radiographics. 2006;26 (suppl 1): S19-S41. Radiographics (full text) - doi:10.1148/rg.26si055174
- 6. Absoud M, Hikmet F, Dey P et-al. Bilateral cavernous sinus thrombosis complicating sinusitis. J R Soc Med. 2006;99 (9): 474-6. doi:10.1258/jrsm.99.9.474 - Free text at pubmed - Pubmed citation