Pyogenic brain abscess, a 15 year survey.

Background: Brain abscess is a potentially fatal disease. This study assesses clinical aspects of brain abscess in a large hospital cohort.

Methods: Retrospective review of adult patients with pyogenic brain abscess at Rigshospitalet University Hospital, Denmark between 1994 and 2009. Prognostic factors associated with Glasgow Outcome Score (GOS) (death, severe disability or vegetative state) were assessed by logistic regression.

Results: 102 patients were included. On admission, only 20% of patients had a triad of fever, headache and nausea, 39% had no fever, 26% had normal CRP and 49% had no leucocytosis. Median delay from symptom onset to antibiotic treatment was 7 days (range 0-97 days). Source of infection was contiguous in 36%, haematogenous in 28%, surgical or traumatic in 9% and unknown in 27% of cases. Abscess location did not accurately predict the portal of entry. 67% were treated by burr hole aspiration, 20% by craniotomy and 13% by antibiotics alone. Median duration of antibiotic treatment was 62 days. No cases of recurrent abscess were observed. At discharge 23% had GOS ≤3. The 1-, 3- and 12-month mortality was 11%, 17% and 19%. Adverse outcome was associated with a low GCS at admission, presence of comorbidities and intraventricular rupture of abscess.

Conclusions: The clinical signs of brain abscess are unspecific, many patients presented without clear signs of infection and diagnosis and treatment were often delayed. Decreased GCS, presence of comorbidities and intraventricular rupture of brain abscess were associated with poor outcome. Brain abscess remains associated with considerable morbidity and mortality.