Acute ventriculitis due to Streptococcus intermedius following periventricular cerebritis

Abstract

Case Presentation: A 57-year-old woman with pulmonary hypertension secondary to congenital heart disease and atrial flutter on anticoagulation presented with a one-week history of pulsatile headache associated with photophobia, phonophobia, and nausea, without fever. On admission, she was oriented and cooperative, but bradyphrenic, without focal neurological deficits or meningeal signs. Initial brain computed tomography (CT) demonstrated asymmetric lateral ventricles, with right-sided predominance and mild hydrocephalus. After temporary discontinuation of anticoagulation, lumbar puncture (LP) was performed, revealing pleocytosis (3,453 cells/mm³, 85% polymorphonuclear cells), elevated protein (910 mg/dL), hypoglycorrhachia (16 mg/dL), elevated lactate (120 mg/dL), and xanthochromic appearance. Empirical treatment with vancomycin, ceftriaxone, and dexamethasone was initiated. On the third hospital day, she developed somnolence and gait disturbance. Repeat imaging demonstrated dilation of the right lateral ventricle associated with hypodense intraventricular material within the right occipital horn and periventricular contrast enhancement. A subsequent LP showed worsening inflammatory parameters (8,787 cells/mm³; protein 629 mg/dL). On the fifth day, she developed decreased level of consciousness, requiring intubation, and progressed to acute hydrocephalus, necessitating external ventricular drainage. Cerebrospinal fluid analysis revealed gram-positive cocci, later identified as Streptococcus intermedius. Despite broad-spectrum antibiotic therapy, she evolved with refractory septic shock and died. Discussion: Ventriculitis is an infection of the ventricular system, typically resulting from extension of meningitis or adjacent parenchymal infection. Clinically, it presents with altered mental status, headache, and fever, although early manifestations may be nonspecific. Diagnosis relies on the combination of clinical, cerebrospinal fluid, and microbiological findings, typically including pleocytosis, elevated protein, and low glucose levels. CSF culture is essential but may initially be negative, particularly after antibiotic therapy. Imaging findings, such as intraventricular debris and hydrocephalus, support the diagnosis. Streptococcus intermedius, a member of the Streptococcus anginosus group, colonizes the oral cavity and is frequently involved in suppurative central nervous system infections. Progression from cerebritis to ventriculitis, as observed in this case, reflects local dissemination and is associated with high morbidity and mortality. Final Comments: This case highlights ventriculitis as a severe complication of central nervous system infection, which may rapidly evolve from periventricular cerebritis. Retrospective imaging review demonstrated right ventricular ectasia associated with a periventricular hypodense area suggestive of early cerebritis, likely progressing with rupture into the ventricular system and severe meningitis.