Brain abscess: pathophysiology, diagnosis, and management – a single centre prospective study

Abstract

Background: Brain abscess is a life-threatening intracranial infection, typically caused by contiguous spread (e.g., sinusitis) or hematogenous seeding (e.g., endocarditis), and is more common in males and in developing countries, with peak incidence in the first two decades of life. Symptoms include headache, fever, altered mental status, nausea/vomiting, seizures (25–34%), and focal neurological deficits. It progresses through four stages over 2–4 weeks, culminating in capsule formation. Diagnosis is best achieved with MRI (especially DWI and ¹H-MRS), which differentiates abscesses from tumors, while CT supports localization and monitoring. Treatment involves ≥6 weeks of BBB-penetrating antibiotics and surgery—stereotactic aspiration for abscesses >2.5 cm, or excision for complex cases. Corticosteroids are used cautiously; anticonvulsants may be continued long-term. With prompt combined therapy, cure rates exceed 90%. Close imaging follow-up is essential to detect complications. This study highlights significant variability in presentation, pathology, management, and outcomes among surgical patients.

Methods: This prospective study analyzed 17 patients with brain abscess treated surgically at the Department of Neurosurgery, SVP Hospital and SMT. NHL Medical College, Ahmedabad, between January 2022 and August 2025. Inclusion required microbiological/histopathological confirmation of infection, characteristic MRI/CT findings, and lesion resolution with antibiotics; cases due to postoperative complications or meningioencephalitis were excluded. All patients underwent baseline and serial CT scans to evaluate abscess size, wall morphology, and perifocal edema. Abscesses ≥2 cm were managed surgically—predominantly via craniotomy and excision—while those <2 cm received medical therapy alone. Empirical broad-spectrum intravenous antibiotics were initiated immediately, adjusted based on culture and sensitivity, and continued for six weeks. Adjunctive corticosteroids were given under antibiotic cover and tapered over four weeks. Postoperative CT was performed within 24 hours, followed by imaging at 1, 3, and 6 months. Clinical outcomes were assessed using the modified Rankin Scale. The study underscores a standardized, multimodal approach to brain abscess management with favorable outcomes.

Results: This prospective study analyzed 17 brain abscess patients (8 males, 9 females; median age 29 years) treated at SVP Hospital, Ahmedabad (Jan 2022–Aug 2025). Most common symptoms were fever/meningeal signs (11), seizures (5), headache (5), and neurological deficits (6). Temporo-parietal location predominated (11 cases); mean abscess size was 4.5 cm. Sixteen underwent craniotomy with excision; one had aspiration. All received 6 weeks of IV antibiotics (adjusted per culture) and a 4-week steroid taper. Causative organisms were identified in 10 cases (Staphylococcus spp., Streptococcus, M. tuberculosis, Aspergillus, hydatid cyst); 6 were culture-negative. Complications included ventriculitis with hydrocephalus (1), managed with ventriculostomy ± VP shunt. At 6 months, 88.23% had good outcomes (mRS 0–2); 2 patients died (one with congenital heart disease and altered sensorium, the other from meningitis/encephalitis). No recurrences occurred. Early diagnosis, surgical excision, and prompt antimicrobial therapy significantly predicted favorable outcomes (p < 0.001).

Conclusion: CNS infections remain life-threatening, demanding urgent multimodal care. Pyogenic brain abscesses >2 cm require emergent surgery—usually burr-hole aspiration; craniotomy is reserved for complex cases. Prolonged (≥6 weeks) IV antibiotics prevent relapse. Despite challenges like diagnostic delays and antimicrobial resistance, outcomes have improved with advanced diagnostics, targeted therapy, and neurocritical care. Timely treatment yields excellent recovery. Reducing the global burden requires equitable access, innovation, and a holistic approach spanning prevention to rehabilitation.