# Brain Abscess Caused by Listeria monocytogenes: A Rare Case of Supratentorial Neurolisteriosis

## TL;DR

A rare case of brain abscess caused by Listeria monocytogenes in an elderly immunocompromised patient highlights the importance of early diagnosis and treatment.

## Contribution

This paper presents a rare case of supratentorial brain abscess caused by Listeria monocytogenes in an elderly patient.

## Key findings

- Listeria monocytogenes can cause supratentorial brain abscess in immunocompromised elderly patients.
- Early diagnosis and treatment led to a good clinical outcome in this case.
- High suspicion is needed for timely diagnosis in at-risk populations.

## Abstract

Listeria monocytogenes is a Gram-positive bacillus that presents a tropism for the central nervous system (CNS). In fact, CNS involvement occurs in over two-thirds of infections caused by this agent. Meningitis is the most common manifestation, while brain abscess is rare.

We present the case of a 77-year-old male patient on corticosteroid treatment for bronchiolitis obliterans organizing pneumonia with a history of unpasteurized cheese consumption, who presented with fever and altered mental status. Brain computerized tomography scan revealed left frontal cortico-subcortical hypodensity mimicking an ischemic stroke. Subsequent magnetic resonance imaging revealed a brain abscess, and blood cultures yielded Listeria monocytogenes. A good clinical outcome was achieved after appropriate antimicrobial therapy and abscess drainage.

This case underscores the importance of considering Listeria monocytogenes in CNS infections, especially in immunocompromised individuals over 65 years of age. The atypical supratentorial involvement challenges the more common rhombencephalitis presentation.

Maintaining a high level of suspicion in relevant populations is crucial for timely diagnosis and intervention, especially in patients with comorbidities, who present particularly high mortality rates.