Multiple brain abscesses following surgical treatment of a perianal abscess

We report a case of multiple brain abscesses (BAs) in a 67-year-old man with symptoms of progredient disorientation and amnestic aphasia. Onset of symptoms occurred one week after surgical treatment of a perianal abscess. No other source of infection was identified and the abscesses were limited to the brain. The immune status was normal but a patent foramen ovale (pFO) was found. The patient was treated with high-dose antibiotics, leading to a complete radiological disappearance of the BAs. Hematogenous spread of infectious emboli from a perianal focus exclusively to the brain is very rare. In our patient, the mechanisms of infectious spread into the brain might have occurred via a cardiac right-to-left shunt or alternatively via the non-valvular vertebral venous system. In this manuscript, both pathways are critically reviewed.