Clinical features and outcome of brain abscess after introduction of CT and MRI: A meta-analysis

Objective: To describe the clinical features and outcome of brain abscess since introduction of computerised tomography and magnetic resonance imaging. Methods: MEDLINE and Embase were searched using “brain abscess” or “cerebral abscess” from 1970 through 2023 and analyses restricted to study populations hospitalised after 1980. Single-variable meta-analyses were done using a random-effects model. Results: A total of 21,840 patients from 209 studies were included. The mean age was 34 years (95% confidence interval [CI] 30–38) and 11,817/17,406 (66%, 95% CI 64–67) were male. The aetiologies were consistent across time and continents with Streptococcus spp. 2064/6393 (32%, 95% CI 28–36), Staphylococcus spp. 1061/6393 (14%, 95% CI 12–16), and Gram-negative enteric bacteria 696/6393 (9%, 95% CI 7–11) as the most common. Predisposing conditions included otitis media/mastoiditis 1909/6433 (27%, 95% CI 22–33), immunocompromise 1022/4652 (19%, 95% CI 14–24), sinusitis 565/3725 (16%, 95% CI 12–20), and neurosurgery 745/4927 (16%, 95% CI 12–20). The case-fatality was 2444/18,991 (12%, 95% CI 11–14) and good recovery was found in 3419/5409 (63%, 95% CI 58–68). Conclusions and relevance: Brain abscess remains a disease predominantly occurring in men and is caused by contiguous or distant infections. Case fatality and outcome have not improved during recent decades.