Brainstem infarcts as an early manifestation of Streptococcus anginosus meningitis

Background and Purpose: Vasculitis and infarcts are well-established sequelae of bacterial meningitis. However, early large-vessel involvement is rare, particularly within the brainstem. There has been one previous case report of a young male who presented with pontine infarct as an early manifestation of Streptococcus milleri meningitis. We present another case of brainstem infarction associated with meningitis caused by Streptococcus anginosus (previously referred to as S. milleri group). Case Description: We report a 58-year-old man who developed constitutional symptoms and gait instability, followed by progressive stupor. On examination, he had a Glasgow Coma Scale of 8 with intact brainstem reflexes and no focal findings. Magnetic resonance imaging documented bilateral pontine infarcts. S. anginosus was isolated from cerebrospinal fluid. Despite proper antibiotic treatment, the patient remained comatose and care was withdrawn. Postmortem examination revealed the meningitis was predominantly localized at the base of the brain. In addition, ventriculitis, multiple abscesses, and multiple infarcts in the pons and midbrain were found. Conclusion: S. anginosus, which is part of the normal human flora, causes invasive pyogenic infections and is an uncommon cause of bacterial meningitis. This type of infection is mostly situated at the base of the brain and has a propensity to encase the basilar artery and its perforators, thus causing brainstem stroke early in its course.