Subdural empyema in bacterial meningitis

Objective: To evaluate the occurrence, treatment, and outcome of subdural empyema complicating community-acquired bacterial meningitis in adults.

Methods: Case series from a prospective nationwide cohort study from Dutch hospitals from 2006 to 2011.

Results: Subdural empyema was diagnosed in 28 of 1,034 episodes (2.7%), and was present on admission in 10 episodes and diagnosed during admission in 18. Predisposing conditions were present in 26 patients (93%), and consisted of otitis or sinusitis in 21 patients (75%). In all these patients the otitis or sinusitis spread to the subdural space. Twenty-three patients (82%) presented with neurologic symptoms (paresis, focal seizures, dysesthesia contralateral to the empyema). Streptococcus pneumoniae was identified in 26 patients (93%) and Streptococcus pyogenes in 1 (3%); 1 patient had negative CSF cultures. Clinical course was frequently complicated with seizures (50%), focal neurologic abnormalities (54%), and hearing impairment (39%), causing an unfavorable outcome in 19 episodes (68%). Neurosurgical evacuation of the empyema was performed in 5 patients, all with considerable midline shift.

Conclusions: Although rare, subdural empyema must be considered in patients with community-acquired bacterial meningitis and otitis or sinusitis, focal neurologic deficits, or epileptic seizures. S pneumoniae is the predominant causative organism and neurosurgical intervention should be regarded as first-choice therapy in patients with empyema causing midline shift and focal neurologic abnormalities or a decreased level of consciousness.