Images of the month: Cavernous sinus venous thrombosis secondary to Streptococcus milleri maxillary sinusitis: An unusual cause of diplopia and headache.

Cavernous sinus venous thrombosis is an uncommon condition associated with high mortality rates if not recognised early. Symptoms include headache, visual loss, ophthalmoplegia, altered consciousness, proptosis and periorbital oedema. High-quality imaging is critical in early diagnosis and successful management. Primary infection (such as sinusitis) and possible complications (including meningitis) should be considered as potential aetiologies of cavernous sinus venous thrombosis, especially in those with a preceding history of localised infection. We present a case of a 50-year-old man with a bilateral cavernous sinus venous thrombosis with associated meningitis caused by Streptococcus milleri, secondary to maxillary sinusitis and otomastoiditis. He was successfully treated with antimicrobial treatment, surgical drainage and anticoagulation. © Royal College of Physicians 2020. All rights reserved.