Infectious brain abscesses and granulomas: analysis of 110 episodes in adults

Background: Infectious brain abscesses and granulomas, characterized by localized collections of pus or inflammatory tissue within the brain parenchyma, pose significant clinical challenges due to their potentially life-threatening nature and complex management requirements. Methods: This cross-sectional study investigated patients diagnosed with infectious brain abscesses and granulomas from March 1, 2012, to October 22, 2021, in Mashhad, Iran. Data were collected from adult patients admitted to the two primary referral centers for community-acquired neuroinfections and neuroinflammations. Demographic information, clinical features, laboratory and neuroimaging characteristics, and clinical outcomes were analyzed. Results: A total of 110 episodes were identified in 106 patients, with a median age of 45 years (IQR 30-56.3) and 62.7% male. Predisposing conditions included immunocompromised states (27.5%), preceding otitis/mastoiditis (16.2%), sinusitis (13.3%), and pulmonary infections (17.2%). The most common clinical manifestations were headache (57.3%), fever (49.1%), altered consciousness (44.4%), and seizures (31.8%). Neuroimaging revealed that brain lesions were solitary in 51% and multiple in 48% of episodes. Surgical intervention was performed in 46.4% of cases. The in-hospital mortality rate was 24.5%, with significant associations found between mortality and factors such as age, altered consciousness, multiple brain lesions, and cerebellum and brainstem involvement. The median length of hospital stay was 28 days (IQR 16-46.5). Conclusion: Our study underscores challenges in diagnosing and treating brain abscesses and granulomas, with high mortality rates (24.5%) despite advanced techniques. Age, altered consciousness, and lesion characteristics predict death. Addressing changing microbial patterns and improving diagnostics are vital for better outcomes, especially in low- and middle-income countries.