The outcome of intracranial subdural empyema at Steve Biko Academic Hospital : retrospective study

Abstract

Objectives: Intracranial subdural empyema (ICSDE) can be a devastating condition, with a sequelae ranging from epilepsy, focal deficits to death. Factors affecting the outcome in subdural empyema range from level of consciousness, the extend of subdural pus at the time of diagnosis and the type of surgical procedure performed. Previous studies have conflicting results of unfavourable prognostic factors associated with ICSDE. The outcome of this condition at Steve Biko Academic Hospital (SBAH) is reported, as well as factors influencing the outcome. Methods: A retrospective analysis of all the patients admitted at neurosurgery unit of SBAH during 2006 – 2010 period with confirmed subdural empyema on brain CT scan and at surgery. Data sheet was used to collect all clinical information from patients’ records. Glasgow Outcome Scale and Henk W. Mauser grading were used to report on the outcome. Results: A total of 34 patients (20 males and 14 females) with mean age of 16.1 years were admitted with a diagnosis of ICSDE. The common presenting features were headache (58.8%), fever and seizures (47.0% each). Over 61% of patients had hemiplegia at presentation. CT scan confirmed subdural collections with 70.6% over the convexity, 23.5% at the convexity and parafalx and only 5.9% had bilateral collections. Complicated paranasal sinusitis was the origin of infection in 82.3%, followed by meningitis with 8.8%. Burr hole washout was done in 52.9% of patients, while 38.2% had burr holes with drains in situ and 8.8% had craniotomy to evacuate the subdural pus. All the patients were given empiric triple antibiotic therapy. Streptococci species were the most cultured organisms in the 19 (56.0%) patients who had positive cultures, however 15 (44.0%) patients had negative cultures. Resistance to penicillin was noted in 5.0% of cases only. Sixty-five percent of patients had good outcome with no seizures nor neurological deficits. The overall mortality was 15.0% in this study, with none from patients who had craniotomy. Conclusion: Clinical presenting features and organisms cultured seems to be the same internationally, particularly those due to complicated sinusitis. Empiric triple antibiotic therapy of 3rd generation cephalosporin plus vancomycin plus metronidazole is still relevant at SBAH. Factors associated with favourable outcome were ages between 11 and 20 years, and craniotomy as the surgical procedure of choice.