Subdural and epidural empyema: diagnostic and therapeutic problems.

OBJECTIVE

A clinical and microbiological review of cases of subdural and epidural empyema.

DESIGN, SETTING, PATIENTS: A 10-year retrospective review of patients with subdural and epidural empyema in all Brisbane hospitals with neurosurgical units. In this period there were 14 cases.

RESULTS

The paranasal sinuses were the primary focus in 8 of the 14 cases, the middle ear in 3 and a surgical or traumatic wound in 2. One case occurred as a complication of Haemophilus influenzae meningitis. Streptococci, particularly Streptococcus milleri, were the causative organisms in all cases of sinus origin, most of which occurred in the second decade of life. An intracranial collection was considered in the differential diagnosis within 24 hours of admission in all 3 cases of otic origin but in only 2 of the 10 sinus or post-traumatic cases. The most common initial diagnosis was viral or partially-treated bacterial meningitis (8 of 13 cases). The initial computed tomographic (CT) scan was not diagnostic in 3 of 11 patients. No patient was successfully treated without surgery, and all 3 deaths in the series were associated with delayed surgery.

CONCLUSIONS

Subdural and epidural empyema is an uncommon condition. The majority of the cases in this series were associated with sinusitis, and Streptococcus milleri was the commonest organism identified. The condition remains a diagnostic challenge; CT scanning cannot be relied upon although the use of intravenous contrast and more modern scanners has improved the diagnostic yield. Surgical drainage and early aggressive antimicrobial therapy are essential to avoid significant morbidity and mortality.