Atypical Presentation of an Odontogenic Brain Abscess Due to Eggerthella lenta and Bilophila wadsworthia Coinfection.

Odontogenic brain abscesses are uncommon. Eggerthella lenta and Bilophila wadsworthia are anaerobes that are normal components of the human intestinal microbiota. Both can also be found in the oral cavity. We report the case of an 81-year-old man with a brain abscess caused by coinfection of E. lenta and B. wadsworthia associated with periodontitis. The patient underwent a right frontal craniotomy with excision of the abscess. Ceftriaxone and metronidazole were then started, along with levetiracetam. Ceftriaxone and metronidazole were maintained for four weeks, and the antibiotic treatment was switched to oral cephalexin and metronidazole for an additional two weeks. Immune senescence and bacterial translocation play an important role in pathogenesis. Early detection, surgical excision of the abscess, and antibiotic therapy resulted in a favorable clinical outcome.