Seizures in adults with bacterial meningitis

Abstract

Objective: To evaluate the occurrence and prognostic relevance of seizures in adults with community-acquired bacterial meningitis.

Methods: An observational cross-sectional study, in which patients with seizures are selected from a prospective nationwide cohort of 696 episodes of community-acquired bacterial meningitis, confirmed by culture of CSF in patients aged >16 years. We retrospectively collected data on EEGs.

Results: Seizures occurred in 121 of 696 episodes (17%). Death occurred in 41% of patients with seizures compared to 16% of patients without seizures (p < 0.001). The median number of seizures was 2 (interquartile range [IQR] 1 to 4). The median time between admission and the first seizure was 1 day (IQR 0 to 3). Patients with in-hospital seizures were more likely to have a CSF leukocyte count below 1,000 cells/mm³ (36% vs 25%; p = 0.01), had higher median CSF protein levels (4.8 g/L [IQR 3.4 to 7.6] vs 4.1 g/L [IQR 2.1 to 6.8]), and higher median erythrocyte sedimentation rate (46 mm/hour [IQR 31 to 72] vs 36 mm/hour [IQR 18 to 69]; p = 0.02) than patients without in-hospital seizures. Focal cerebral abnormalities developed more often in patients with in-hospital seizures than in those without (41% vs 14%; p < 0.001). In a multivariate analysis, seizures were significantly more likely in patients with predisposing conditions, tachycardia, a low Glasgow Coma Scale score on admission, infection with Streptococcus pneumoniae, and focal cerebral abnormalities. Neuroimaging was performed on admission in 70% of episodes with prehospital seizures, with CT revealing a focal lesion in 32% of those episodes. Antiepileptic drugs were administered in 82% of patients with seizures and EEG was performed in 31% of episodes; a status epilepticus was recorded in five patients.

Conclusions: Seizures occur frequently in adults with community-acquired bacterial meningitis. Seizures are associated with severe CNS and systemic inflammation, structural CNS lesions, pneumococcal meningitis, and predisposing conditions. The high associated mortality rate warrants a low threshold for starting anticonvulsant therapy in those with clinical suspicion of a seizure.