Short-and Long-Term Outcomes after Status Epilepticus
Authors: Waterhouse Elizabeth J. 
Published: December 2022

Refractory Status Epilepticus Frequency, Risk Factors, and Impact on Outcome

Mayer SA, Claassen J, Lokin J, Mendelsohn F, Dennis LJ, Fitzsimmons B-F

Arch Neurol 2002;59:205–210

Refractory status epilepticus (RSE) is a life-threatening condition in which seizures do not respond to first- and second-line anticonvulsant drug therapy. How often RSE occurs, risk factors that predispose to this condition, and the effect of failure to control seizures on clinical outcome are poorly defined.

Objective

To determine the frequency, risk factors, and impact on outcome of RSE.

Design

Retrospective cohort study.

Setting

Large academic teaching hospital.

Patients

Consecutive sample of 83 episodes of status epilepticus in 74 patients (mean age, 63 years). Main outcome.

Methods

Refractory status epilepticus was defined as seizures lasting longer than 60 minutes despite treatment with a benzodiazepine and an adequate loading dose of a standard intravenous anticonvulsant drug. Factors associated with RSE were identified using univariate and backward stepwise logistic regression analyses.

Results

In 57 episodes (69%), seizures occurred after treatment with a benzodiazepine, and in 26 (31%), seizures occurred after treatment with a second-line anticonvulsant drug (usually phenytoin), fulfilling our criteria for RSE. Nonconvulsive SE (P = .03) and focal motor seizures at onset (P = .04) were identified as independent risk factors for RSE. Eleven (42%) of 26 patients with RSE had seizures after receiving a third-line agent (usually phenobarbital). Although mortality was not increased (17% overall), RSE was associated with prolonged hospital length of stay (P < .001) and more frequent functional deterioration at discharge (P = .02).

Conclusions

Refractory status epilepticus occurs in approximately 30% of patients with SE and is associated with increased hospital length of stay and functional disability. Nonconvulsive SE and focal motor seizures at onset are risk factors for RSE. Randomized controlled trials are needed to define the optimal treatment of RSE. Long-term Mortality After a First Episode of Status Epilepticus Logroscino G, Hesdorffer DC, Cascino GD, Annegers JF, Bagiella E, Hauser WA Neurology 2002;58:537–541

Objective

To evaluate long-term mortality among people with status epilepticus (SE).

Methods

The authors performed a population-based retrospective cohort study to determine long-term mortality after SE. Between January 1, 1965, and December 31, 1984, all first episodes of SE receiving medical attention were ascertained through the Rochester Epidemiology Project Records-Linkage System. Cases surviving the first 30 days (n = 145) were followed until death or study termination (February 1996).

Results

At 10 years, cumulative mortality among 30-day survivors was 43%. The standardized mortality ratio (SMR) at 10 years was 2.8 (95% CI, 2.1–3.5). The mortality rate of those with idiopathic/cryptogenic SE was not increased (SMR = 1.1; 95% CI, 0.5–2.3). The following characteristics of SE increased long-term risk for mortality: SE ≥ 24 hours in duration vs. SE < 2 hours (relative risk [RR] = 2.3; 95% CI, 1.1–5.1); acute symptomatic etiology vs. idiopathic/cryptogenic etiology (RR = 2.2; 95% CI, 1.0–5.1); myoclonic SE vs. generalized convulsive SE (RR = 4.0; 95% CI, 1.3–13).

Conclusion

Forty percent of subjects who survived the first 30 days after an incident episode of SE die within the next 10 years. The long-term mortality rate was threefold that of the general population over the same time period. The long-term mortality rate at 10 years was worse for those with myoclonic SE, for those who presented with SE lasting more than 24 hours, and for those with acute symptomatic SE. The long-term mortality rate was not altered in those with idiopathic/cryptogenic SE. We conclude that SE alone does not modify long-term mortality.