Seizures do not increase in-hospital mortality after intracerebral hemorrhage in the nationwide inpatient sample

Abstract

Background: Seizures are common after intracerebral hemorrhage (ICH) but their impact on outcome is uncertain and prophylactic anti-convulsant use is controversial. We hypothesized that seizures would not increase the risk of in-hospital mortality in a large administrative database.

Methods: The study population included patients in the 2006 Nationwide Inpatient Sample over the age of 18 with a principal diagnosis of ICH (ICD9 = 431). Subjects with a secondary diagnosis of aneurysm, arterio-venous malformation, brain tumor, or traumatic brain injury were excluded. Seizures were defined by ICD9 codes (345.0x-345.5x, 345.7x-345.9x, 780.39). Logistic regression was used to quantify the relationship between seizures and in-hospital mortality. Pre-specified subgroups included age strata, length of stay, and invasive procedures.

Results: 13,033 subjects met all eligibility criteria, of which 1,430 (11.0 %) had a secondary diagnosis of seizure. Subjects with seizure were younger (64 vs. 70 years, p < 0.001), more likely to get craniectomy (2.1 vs. 1.2 %, p = 0.006), ventriculostomy (8.5 vs. 6.0 %, p < 0.001), intubation (32.2 vs. 25.9 %, p < 0.001), and tracheostomy (6.4 vs. 4.2 %, p < 0.001). Seizure patients had lower in-hospital mortality (24.3 vs. 28.0 %, p = 0.003). In a multivariable model incorporating patient and hospital level variables, seizures were associated with reduced odds of in-hospital death (OR = 0.62, 95 % CI 0.52-0.75).

Conclusions: A secondary diagnosis of seizure after ICH was not associated with increased in-hospital death overall or in any of the pre-specified subgroups; however, there may be residual confounding by severity. These findings do not support a need for routine prophylactic anti-epileptic drug use after ICH.