Mortality in epilepsy following brain infections in adults: A register-based population-wide study

Objective

Acquired epilepsy is associated with increased risk of death, but whether this extends to epilepsy after brain infections is unknown. Our objective was to estimate mortality and causes of death in patients with epilepsy after four types of brain infections.

Methods

A population-wide Swedish cohort was created from the National Patient Registry, including all patients over 18 years of age who received inpatient care in 2000–2010 for herpes encephalitis, brain abscesses, other encephalitis, or bacterial meningitis. Cox proportional hazards modelling was used to compare the hazard ratio for death after epilepsy, adjusting for age, sex, disease severity and comorbidities.

Results

A total of 5446 subjects fulfilled the inclusion criteria, out of which 574 had post-infectious epilepsy. In time-updated and adjusted Cox proportional hazards models, epilepsy was associated with an increased risk of death in patients surviving bacterial meningitis (HR 1.7 [1.3–2.4]) or other encephalitis (HR 2.6 [1.9–3.5]), but not brain abscesses or herpes encephalitis. Dominating causes of death were vascular causes and neoplasms.

Significance

The difference in associations between epilepsy and death after different brain infections, in combination with epilepsy being a rare underlying cause of death, suggests that patients with postinfectious epilepsy may not only need optimal epilepsy treatment, but also careful attention to particularly vascular comorbidities.