Prognostic factors, morbidity and mortality in tonic-clonic status epilepticus: a review

Status epilepticus: a review, with emphasis on refractory cases

Status epilepticus is among the most dramatic of clinical presentations encountered by emergency room physicians, neurologists, neurosurgeons and intensivists. While progress in its management has been aided significantly with an increasing number of effective treatment options, improved diagnostic methods and more effective monitoring, poor outcomes and diagnostic failures are still frequently encountered. Refractory cases still carry significant morbidity and mortality rates, including poor cognitive outcomes. This review discusses basic pathophysiology and management of status epilepticus, neuroimaging findings, the role of continuous electroencephalogram monitoring and nonconvulsive status epilepticusas well as recent developments in treatment options for refractory cases.

Temporal lobe epilepsy after refractory status epilepticus: an illustrative case and review of the literature

New onset refractory status epilepticus (NORSE) is a relatively newly defined disease entity, where otherwise healthy individuals develop unrelenting seizures that do not respond to conventional anticonvulsant therapy and may require months of therapy with anesthetic drugs. We have described a case of NORSE who subsequently developed mesial temporal lobe sclerosis (MTS) and recurrent temporal lobe seizures. We discuss the possible pathophysiological mechanisms by which refractory seizures may contribute to the development of temporal lobe epilepsy (TLE).

Role of comorbidities in outcome prediction after status epilepticus

Status epilepticus (SE) is associated with significant mortality and morbidity. A reliable prognosis may help better manage medical resources and treatment strategies. We examined the role of preexisting comorbidities on the outcome of patients with SE, an aspect that has received little attention to date. We prospectively studied incident SE episodes in 280 adults occurring over 55 months in our tertiary care hospital, excluding patients with postanoxic encephalopathy. Different models predicting mortality and return to clinical baseline at hospital discharge were compared, which included demographics, SE etiology, a validated clinical Status Epilepticus Severity Score (STESS), and comorbidities (assessed with the Charlson Comorbidity Index) as independent variables. The overall short-term mortality was 14%, and only half of patients returned to their clinical baseline. On bivariate analyses, age, STESS, potentially fatal etiologies, and number of preexisting comorbidities were all significant predictors of both mortality and return to clinical baseline. As compared with the simplest predictive model (including demographics and deadly etiology), adding SE severity and comorbidities resulted in an improved predictive performance (C statistics 0.84 vs. 0.77 for mortality, and 0.86 vs. 0.82. for return to clinical baseline); comorbidities, however, were not independently related to outcome. Considering comorbidities and clinical presentation, in addition to age and etiology, slightly improves the prediction of SE outcome with respect to both survival and functional status. This analysis also emphasizes the robust predictive role of etiology and age.

New insight on the mechanisms of epileptogenesis in the developing brain

The incidence of epilepsy is at its highest in childhood and seizures can persist for a lifetime. As brain tissue from pediatric patients with epilepsy is rarely available, the analysis of molecular and cellular changes during epileptogenesis, which could serve as targets for treatment approaches, has to rely largely on the analysis of tissue from animal models. However, these data have to be analyzed in the context of the developmental stage when the insult occurs. Here we review the current status of the available animal models, the molecular analysis done in these models, as well as treatment attempts to prevent epileptogenesis in the immature brain. Considering that epilepsy is one of the major childhood neurological diseases, it is remarkable how little is known on epileptogenesis in the immature brain at a molecular level. It is a true challenge for the future to expand the armamentarium of clinically relevant animal models, and systematic analysis of molecular and cellular data to enhance the probability of developing syndrome specific antiepileptogenic treatments and biomarkers for acquired pediatric epileptogenesis.

Management of refractory status epilepticus in adults: still more questions than answers

Refractory status epilepticus (RSE) is defined as status epilepticus that continues despite treatment with benzodiazepines and one antiepileptic drug. RSE should be treated promptly to prevent morbidity and mortality; however, scarce evidence is available to support the choice of specific treatments. Major independent outcome predictors are age (not modifiable) and cause (which should be actively targeted). Recent recommendations for adults suggest that the aggressiveness of treatment for RSE should be tailored to the clinical situation. To minimise intensive care unit-related complications, focal RSE without impairment of consciousness might initially be approached conservatively; conversely, early induction of pharmacological coma is advisable in generalised convulsive forms of the disorder. At this stage, midazolam, propofol, or barbiturates are the most commonly used drugs. Several other treatments, such as additional anaesthetics, other antiepileptic or immunomodulatory compounds, or non-pharmacological approaches (eg, electroconvulsive treatment or hypothermia), have been used in protracted RSE. Treatment lasting weeks or months can sometimes result in a good outcome, as in selected patients after encephalitis or autoimmune disorders. Well designed prospective studies of RSE are urgently needed.

Complications of the management of status epilepticus in the intensive care unit

Barbiturates and propofol are widely used to control status epilepticus. This review aims to discuss all possible adverse effects incurred by the administration of GABA-mediated anesthetic agents. Further on unconventional therapies such as ketamine, lidocaine, or anesthetic agents are discussed both with respect to efficacy and complications. The aim of this review is to raise awareness of complications incurred by therapeutic approaches to patients with status epilepticus in the intensive care unit.

Treatment of pediatric status epilepticus

OPINION STATEMENT

Status epilepticus is characterized by a prolonged, self-sustaining seizure or repeated seizures without return to baseline. The clinical manifestations of status epilepticus in children and adults range from overt generalized convulsions to more subtle behavioral manifestations, including unresponsiveness in the setting of the intensive care unit. Status epilepticus is the most common neurologic emergency of childhood. A large proportion of these episodes are the result of a prolonged febrile seizure or an acute symptomatic etiology. Fortunately, status epilepticus occurs without consequence for many children, but for others, it is correlated with long-term neurologic dysfunction or death. Treatment of status epilepticus should commence promptly upon its recognition, using predefined treatment protocols. The goal of treatment is the rapid termination of the seizure, to minimize the acute and chronic effects of this emergency and to allow for the prompt assessment and management of the underlying precipitant. Currently, the drug class of first choice in the in-hospital and out-of-hospital treatment of status epilepticus is the benzodiazepines, which may need to be quickly followed by a next-line agent, as the efficacy of the benzodiazepines is negatively correlated with seizure duration. Traditionally, these next-line agents have included phenobarbital and phenytoin, but emerging evidence supports the use of intravenous formulations of other antiepileptic drugs. If the first two agents fail, high-dose intravenous midazolam or anesthetic therapy should be rapidly initiated. This paper reviews the current treatment options and strategies for pediatric patients with status epilepticus.