Pneumococcal meningitis secondary to chronic orbital inflammation with skull base erosion: a case report.

This case report describes a 32-year-old female patient who developed acute pneumococcal meningitis following six-year chronic orbital inflammatory changes after strabismus corrective surgery. The patient experienced gradual deterioration of right-eye vision and recurrent retro-orbital headache; serial magnetic resonance imaging (MRI) from 2021 to 2023 demonstrated diffuse intraconal retrobulbar abnormalities and extraocular-muscle thickening. She subsequently presented with high fever, generalized seizures and impaired consciousness. Cerebrospinal fluid (CSF) metagenomic next-generation sequencing (mNGS) detected Streptococcus pneumoniae and low-abundance Epstein-Barr virus (EBV) DNA; Active EBV-associated central nervous system infection could not be confirmed in the absence of CSF quantitative EBV polymerase chain reaction (PCR), EBV serology and immune-status testing. The patient received broad-spectrum intravenous antimicrobial, antiviral and glucocorticoid therapy, followed by endoscopic endonasal resection of inflammatory lesions at the ethmoid-skull-base complex. Histopathological examination of surgical specimens revealed non-specific inflammatory granulation tissue, and Langerhans cell histiocytosis was excluded. At six-month follow-up, the patient remained seizure-free; infectious foci showed near-complete resolution on imaging, yet mild residual orbital-leptomeningeal abnormalities persisted with modest visual improvement. This case demonstrates the potential for delayed intracranial extension from long-standing chronic orbital inflammation and highlights both the diagnostic utility and interpretive limitations of CSF-mNGS in clinical practice.