# Chronic Basal Ganglia Infarction With PCR‐Identified Paeniclostridium sordellii: A Rare Neuropathological Case Report

## TL;DR

A rare case of brain infection caused by Paeniclostridium sordellii is reported, emphasizing the need for molecular diagnostics in difficult-to-detect CNS infections.

## Contribution

Highlights the diagnostic utility of molecular methods for identifying rare pathogens like P. sordellii in CNS lesions.

## Key findings

- Postmortem NGS confirmed P. sordellii infection in a patient with CNS inflammation.
- Histopathology showed inflammation and vascular changes without hemorrhage.
- Molecular diagnostics were crucial in identifying the rare pathogen.

## Abstract

Within 1 month of diagnosis, 40% of patients with positive blood cultures will develop CNS complications. Rare pathogens, that is, Paeniclostridium sordellii, pose diagnostic challenges due to atypical presentations and detection difficulties.

A 67‐year‐old man presented with metabolic encephalopathy and diabetes insipidus. Imaging showed bilateral basal ganglia abnormalities and an enhancing lesion near the anterior commissure, suspicious for neoplasm. Postmortem findings included reactive gliosis, atypical lymphocytic inflammation, and polyclonal plasma cells. NGS performed at the University of Washington confirmed P. sordellii infection.

The gross and histologic examination showed mild hydrocephalus, right hippocampal atrophy, and anterior commissure–centric inflammation. Vascular congestion, arteriosclerosis with microthrombi, and oligodendrocyte loss were present without hemorrhage.

Hemophagocytic lymphohistiocytosis and CNS lymphoma were considered but ruled out microscopically.

This case highlights the importance of considering P. sordellii in CNS inflammatory lesions and demonstrates the utility of molecular diagnostics in negative cultures.