The cavernous sinus (CS) is a venous plexus that lies between the periosteal and dural layers of the dura mater. It is located at the central base of the skull, on either side of the sella turca.
A large channel of venous blood creating a "sinus" cavity bordered by the sphenoid bone and the temporal bone of the skull. The cavernous sinus is an important structure because of its location and its contents which include the third cranial (oculomotor) nerve, the fourth cranial (trochlear) nerve, parts 1 (the ophthalmic nerve) and 2 (the maxillary nerve) of the fifth cranial (trigeminal) nerve, and the sixth cranial (abducens) nerve (https://www.medicinenet.com/cavernous_sinus/definition.htm).
CS syndrome (CSS) is characterized by signs and symptoms resulting from the compromise of the cranial nerves passing through the CS. Common clinical manifestations include ophthalmoplegia, proptosis, ocular and conjunctival congestion, trigeminal sensory loss and Horner’s syndrome.1 2 Causes can be divided into vascular, traumatic, neoplastic, infectious and miscellaneous inflammatory disorders.
The cavernous sinus is a complex structure susceptible to a wide variety of vascular, neoplastic and inflammatory pathologies. Vascular pathologies include ICA aneurysms, carotid-cavernous fistulas, cavernous sinus thrombosis, and cavernous hemangioma. Neoplasms that involve the cavernous sinus include pituitary adenoma, meningioma, schwannoma, lymphoma, perineural tumor spread, metastases, and direct tumor invasion. Infectious and inflammatory diseases include Tolosa-Hunt syndrome, sarcoidosis, granulomatosis with polyangiitis, IgG-4 related disease and invasive fungal infections.
Video for Mnemonic
Toro, J., Burbano, L. E., Reyes, S., & Barreras, P. (2015). Cavernous sinus syndrome: need for early diagnosis. BMJ case reports, 2015, bcr2014206999. https://doi.org/10.1136/bcr-2014-206999.
Munawar K, Nayak G, Fatterpekar GM, Sen C, Zagzag D, Zan E, Hagiwara M. Cavernous sinus lesions. Clin Imaging. 2020 Dec;68:71-89. doi: 10.1016/j.clinimag.2020.06.029. Epub 2020 Jun 18. PMID: 32574933..