Bacterial brain abscess--experiences with 67 patients

Abstract

Sixty-seven patients with brain abscess were managed over 19 years (1975-1993). Our series had a 2.5 to 1 male predominance; the age distribution was from 3 days to 81 years. The underlying conditions of hematogenic brain abscesses (n = 33; 49%) included lung infections (n = 16), heart disease (n = 4), sepsis (n = 10), and other foci (n = 3). Otolaryngologic infections led to the abscess in 10 cases; there were 9 traumatic abscesses. The causes remained unknown in 15 cases. There were 47 solitary abscesses (70%) and 20 multiple abscesses. The most frequent presenting signs and symptoms were neurologic deficits (n = 17), disturbances of consciousness (n = 14), seizures (n = 6), and headaches, meningism and vomiting (n = 13). Causative organisms were isolated in 39 cases (58%) and included staphylococci (n = 6), streptococci (n = 6), enterobacteriae (n = 2), and anaerobic pathogens (n = 9). The most reliable laboratory sign of inflammation was an elevated ESR (52/59 patients). With the advent of computed tomography, burr hole aspiration of the abscess with or without drainage was possible in 30 cases; the mortality in this subgroup was 9%. All 4 patients with surgical excision in the pre CT-era died. The mortality of patients treated with antibiotics only was 62% (18/29). Overall mortality was 37% (25/67), including 5 cases with post mortem-diagnosis of brain abscess. Good recovery was achieved in 29/42 survivors. Predictors of a poor outcome were the patient's age, the level of consciousness, multiple abscesses, polybacterial cultures, and a hematogenic etiology, but not the size of the abscess.