Clinical differences and prognostic factors for unfavourable outcome in community-acquired versus health care-associated intracranial empyema and abscess

Background Intracranial empyema and brain abscess are rare but severe central nervous system infections. Community-acquired (CA) cases typically arise from sinus, otogenic, dental, or haematogenous sources, whereas health care-associated (HCA) infections occur as postoperative complications following neurosurgical interventions. Comparative data between these entities remain limited. This study assessed clinical presentation, microbiology, intensive care requirements, and outcomes in CA versus HCA infections and identified predictors of unfavourable neurological outcome. Methods We conducted a retrospective single-centre study of adults treated for intracranial empyema or abscess at the University Hospital Zurich (2012–2023). Patients were categorised as CA or HCA. Demographic, clinical, radiological, microbiological, and ICU variables were analysed. The primary outcome was neurological function at discharge and 3–6 months using the Glasgow Outcome Scale–Extended (GOSE). Secondary outcomes included ICU admission, in-hospital mortality, and microbiology. Logistic regression identified predictors of unfavourable outcome. Results Eighty-four patients were included (37 CA, 47 HCA). CA patients were younger (52 vs 59 years; p = 0.047), presented with lower GCS (13.5 vs 14.7; p = 0.024), more frequently had new focal neurological deficits (78.4% vs 40.4%; p = 0.001), disturbances of consciousness (29.7% vs 10.6%; p = 0.048), and sepsis (43.2% vs 21.3%; p = 0.036). ICU admission (81.0% vs 31.9%; p < 0.001) and hospital stay (19 vs 12 days; p = 0.002) were higher in CA patients. Microbiology differed substantially: Staphylococcus aureus was more common in HCA infections (44.7% vs 8.1%; p < 0.001), whereas Streptococcus spp. predominated in CA infections (64.9% vs 4.3%; p < 0.001). Functional outcomes were comparable between groups at discharge (GOSE 7 vs 6; p = 0.144) and follow-up (7 vs 7; p = 0.377). Sepsis (p = 0.003) and low GCS at diagnosis (p = 0.006) predicted unfavourable outcome in univariable analysis; only SAPS II independently predicted mortality (OR 1.20 per point; 95% CI 1.05–1.37; p = 0.009). Conclusion CA infections presented with more severe neurological and systemic impairment but achieved similar long-term functional outcomes as HCA infections. Prognosis appears to depend primarily on initial disease severity rather than infection origin or comorbidity burden. Trial registration Not applicable (retrospective study)