# Basal Ganglia Involvement in Pediatric Mycoplasma pneumoniae Meningoencephalitis: Two Cases and a Literature Review

## TL;DR

This paper reports two cases of pediatric Mycoplasma pneumoniae meningoencephalitis with rare basal ganglia involvement and reviews existing literature on the topic.

## Contribution

The study highlights the rare occurrence of basal ganglia lesions in older children with M. pneumoniae meningoencephalitis and their potential diagnostic significance.

## Key findings

- Two pediatric cases showed bilateral basal ganglia lesions on MRI, confirmed with M. pneumoniae infection.
- Literature review identified 21 cases of basal ganglia involvement in M. pneumoniae-related meningoencephalitis in children.
- Corticosteroid treatment led to full recovery in both reported cases.

## Abstract

Background: Mycoplasma pneumoniae is a common cause of respiratory tract infections in children, but neurological complications, including encephalitis, are increasingly recognized. Basal ganglia involvement is rare, and a poorly characterized feature of meningoencephalitis, with clinical consequences being inconclusive. Methods: We report two pediatric cases of Mycoplasma pneumoniae-related meningoencephalitis with bilateral basal ganglia lesions seen on MRI. A literature review was conducted using PubMed, Scopus, and Web of Science to identify reports of M. pneumoniae-related meningoencephalitis in children, and related MRI findings. Results: Both patients (12-year-old male and 14-year-old female) presented with acute meningoencephalitis syndrome and had marked mononuclear pleocytosis. In both patients M. pneumoniae was confirmed with serological assay from serum sample, while in one patient M. pneumoniae was also confirmed by PCR from pharyngeal swab. Both exhibited bilateral basal ganglia lesions, with complete regression observed during follow-up. Treatment with corticosteroids led to full recovery in both cases. After a literature search, a total of 21 patients had basal ganglia involvement reported. Conclusions: Literature suggests variable MRI findings in pediatric M. pneumoniae encephalitis, with basal ganglia involvement being uncommon and rarely reported, especially among older children. While diagnostic challenges related to extrapulmonary manifestations of the infection persist, basal ganglia involvement could aid in diagnosis, especially in older children presenting with meningoencephalitis along with pronounced pleocytosis when respiratory symptoms are absent or mild.