What is a common cause of cavernous sinus thrombosis?

Cavernous sinus thrombosis is often associated with facial infections, particularly those originating from the teeth or soft tissues of the face. Staphylococcus aureus is a common bacterial pathogen involved in these infections, which can spread to the cavernous sinus area, leading to thrombosis.

The anatomy of the cavernous sinus—located at the base of the skull—makes it susceptible to infections from the face and scalp due to venous connections. Infections in the upper face or teeth can directly spread via valveless veins and result in the formation of a clot within the sinus. This infectious route is particularly problematic as it can lead to serious complications due to the sinus's proximity to critical structures, including cranial nerves and the internal carotid artery.

While blood clot formation in the sinuses or trauma to the skull could theoretically lead to thrombosis, they are not the common causes associated with cavernous sinus thrombosis specifically. Additionally, pneumonia infection does not directly result in cavernous sinus thrombosis as a typical complication and is unrelated to the facial infections typically linked to this condition.