Cavernous sinus thrombosis caused by Streptococcus constellatus-associated Lemierre syndrome presenting as an isolated abducens nerve palsy

PURPOSE: To describe a patient with Streptococcus constellatus-associated Lemierre syndrome complicated by eventual cavernous sinus thrombosis (CST) that manifested as an isolated abducens nerve palsy. OBSERVATIONS: A patient with a history of heavy alcohol use presented with Lemierre syndrome caused by an odontogenic infection due to Streptococcus constellatus. Despite initiation of intravenous antibiotics and eventual eradication of her bacteremia, she developed an isolated abducens nerve palsy on hospital day 7 due to associated CST. CONCLUSIONS AND IMPORTANCE: CST is a rare complication of odontogenic infection and Lemierre syndrome. This case demonstrates the potential for primary odontogenic infections to progress to life- and sight-threatening diseases. This case also illustrates the importance of considering uncommon pathogens as the etiology of CST based on the suspected source of primary infection.