Healthy adults with Streptococcus pneumoniae meningitis and Streptococcus pneumoniae subdural abscess: two case reports and a literature review

Abstract

We present the cases of two otherwise healthy adults, one with meningitis and another with a subdural abscess, with both conditions attributable to Streptococcus pneumoniae. A 31-year-old man was admitted with a 3-day history of fever, headache, and vomiting. Physical examination revealed intermittent confusion, irritability, and neck stiffness. Cerebrospinal fluid (CSF) culture was positive for S. pneumoniae. Contrast-enhanced magnetic resonance imaging (C-MRI) revealed multiple small lesions on the bilateral frontal lobes. Intravenous ceftriaxone and vancomycin were administered, followed by intravenous moxifloxacin. His symptoms resolved within 3 months. Additionally, a 66-year-old man was admitted for acute fever with confusion, abnormal behavior, and a recent history of acute respiratory infection. Physical examination revealed confusion, neck stiffness, and a positive right Babinski sign. CSF metagenomic analysis detected S. pneumoniae. C-MRI disclosed left occipitotemporal meningoencephalitis with subdural abscesses. Intravenous ceftriaxone was administered for 3 weeks. His condition gradually improved, with resorbed lesions detected on repeat MRI. This study expanded the clinical and imaging spectra of S. pneumoniae meningitis. In healthy adults, S. pneumoniae can invade the brain, but subdural abscess is a rare neuroimaging manifestation. Early diagnosis of S. pneumoniae meningitis by high-throughput sequencing and flexible treatment strategies are necessary for satisfactory outcomes.

Keywords: Streptococcus pneumoniae meningitis; case report; healthy adult; magnetic resonance imaging; metagenomic analysis; subdural abscess.

Figure 1.

Manifestation of lesions on brain magnetic resonance imaging. (a) Chest computed tomography revealed multiple inflammatory lesions in both lungs. Brain magnetic resonance imaging revealed (b) hypointense punctate lesions (arrows) in the frontal lobe on axial T1-weighted imaging, (c) hyperintense lesions (arrows) in the bilateral frontal lobes on T2-weighted imaging, (d) fluid-attenuated inversion recovery, and (e, f) diffusion-weighted imaging and (g, h) The lesions were enhanced.

Figure 2.

Characteristics and evolution of lesions on brain magnetic resonance imaging. (a) Magnetic resonance imaging of the left occipitotemporal lobes revealed hypointensity on T1, (b, c) slight hyperintensity on T2 and fluid-attenuated inversion recovery (arrow), and (d, e) hyperintensity on diffusion-weighted imaging (arrow). There was also sulcal narrowing or disappearance in the left parietal-occipital cortex. The occipital-parietal-temporal-frontal meninges were thickened. (f–h) There were arc-shaped lesions with T1 hypointensity and T2 hyperintensity under the corresponding inner plate of the skull on contrast-enhanced magnetic resonance imaging (arrows). At 20 days after discharge, repeat magnetic resonance imaging revealed the disappearance of the hyperintensity on (i) diffusion-weighted imaging and (j) fluid-attenuated inversion recovery, and (k, l) the lesion was completely absorbed.