Introduction

There is wide variation in the reported prognosis among people with status epilepticus (SE). This variation relates to differences in the definition of SE, the etiologic classification of SE, the definition of outcomes, and the study of outcomes in heterogeneous populations. The most important cause of variation is the source of cases, which is an indirect measure of disease severity and etiology. A study from the Netherlands found a sixfold variation in mortality associated with SE across medical care facilities (26). Mortality was lowest in an epilepsy center (1.9%), intermediate in community hospitals (6.7%), and highest in large hospitals and university clinics (11.9%). This variation was related to differences in the mix of etiology of SE in patients seen at these centers. Another example of heterogeneity may be seen in studies reported in this book. The case-fatality ratio was 21% in the population-based studies in Rochester, Minnesota, and Richmond, Virginia (8, 9, 20), but 55% in the Veterans Administration clinical trial of SE treatments (see Treiman, Chapter 6, this volume).

The use of population-based data can provide insights into the frequency of adverse outcomes following SE. In addition, population-based data can allow comparison of outcomes in individuals with seizures or epilepsy but without SE to determine the contribution of SE. It also allows comparison with the frequency of events and outcomes in the general population. This chapter examines the prognosis for SE from a population-based study of people with convulsive disorders and epilepsy (9, 11, 13).