Abstracts

Refractory status epilepticus (RSE) is a severe form of status epilepticus (SE) that does not respond to first and second anticonvulsant treatment efforts. Understanding what causes RSE may provide important insights into the prevention and treatment of this condition. Seizure duration prior to treatment has been suggested to play a role in the development of RSE. This study was initiated to evaluate the role of seizure duration and other factors in the development of RSE. This study identified 148 cases of RSE in a data base of 539 cases of adult SE. These patients were identified prospectively in a population based study in the Richmond NIH SE data base. SE was defined as seizure activity lasting 30 minutes or longer or intermittent seizure activity lasting 30 minutes or longer without regaining consciousness. RSE was defined as SE patients that did not respond to the first and second treatements of anticonvulsant medications. Definitions of etiology, seizure types, and other variables and statistical methods have been described previously (Neurology 1996;46:1029-1035). The effects of seizure duration prior to the initial treatment in influencing the development of RSE were analyzed. Univariate and multivariate analysis of seizure duration prior to first treatment as a predictor of the development of RSE indicated that seizure duration prior to first treatment did not have a statistically significant effect on the development of RSE. Other variables, including age, gender, race, seizure type, location of seizure onset, etiologies, previous seizure history, and laboratory values were evaluated. Specific variables including nonconvulsive SE, location of onset, and previous seizure history were statistically significantly contributing to the development of RSE using both univariate and multivariate statistical analysis. Unexpectedly, etiology did not statistically effect the development of RSE. Further analysis suggests that innovative strategies are needed to elucidate the causes of RSE. Understanding the factors that contribute to the developent of RSE may play an important role in developing novel strategies to prevent and better treat this major neurological condition. Results from this study indicate that time to initial treatment may not play a major role in the development of RSE. Future studies on larger data bases are needed to expand these studies and more clearly dissect out the underlying contributing causes of RSE. Although these studies do not completely rule out time to treatment as a factor contributing to the development of RSE, they indicate that other factors clearly contribute to the development of RSE independent of time to first treatment. (Supported by P50NS25630 from the National Institutes of Health.)