Review of 140 patients with brain abscess

Abstract

There were 140 cases of brain abscess treated between 1980 (when CT scanning became available) and June 1991. These arose by spread of a contiguous area of infection in 37%, and from another identified cause in 22%; the origin was undetermined in 41%. There were multiple abscesses in 11%. The abscess was < 2 cm in diameter in 21%. In two-thirds of the patients, the intracranial pressure was raised, there were localizing neurologic signs in 33%, and in 28% there were epileptic seizures. The computed tomographic (CT) feature of an abscess in the capsular stage was a thin, regular, and uniform, ring-like enhancement. In the cerebritis stage, nine out of 17 patients showed a uniform enhancement throughout the lesion. Since 1989, 14 cases have been investigated with magnetic resonance imaging (MRI). In 11, the abscess was in the capsular stage. In both T1- and T2-weighted images, the abscess and the surrounding inflammatory area were well demonstrated, and with T2-weighting, the capsule showed a low-intensity signal clearly. In the three abscesses in the cerebritis stage, there was a uniform abnormality with indistinct margins between the abscess, inflammatory edema, and surrounding grey and white matter. All cases received a combination of wide-spectrum antibiotics before the organism was identified; and later the medication was administered according to bacteriologic indication of the organism of 112 cases, organisms were identified in 71%, with anaerobic organisms occurring in 30% of these. In 127 cases, surgical treatment was used: either repeated aspiration, excision or both. We treated 13 cases that had small, early, or multiple abscesses with antibiotics only. The mortality with surgical treatment was 7.9%, and no case treated conservatively died.