Medical management of refractory status epilepticus

Insight into Drug Resistance in Status Epilepticus: Evidence from Animal Models

Status epilepticus (SE), a condition with abnormally prolonged seizures, is a severe type of epilepsy. At present, SE is not well controlled by clinical treatments. Antiepileptic drugs (AEDs) are the main therapeutic approaches, but they are effective for SE only with a narrow intervening window, and they easily induce resistance. Thus, in this review, we provide an updated summary for an insight into drug-resistant SE, hoping to add to the understanding of the mechanism of refractory SE and the development of active compounds. Firstly, we briefly outline the limitations of current drug treatments for SE by summarizing the extensive experimental literature and clinical data through a search of the PubMed database, and then summarize the common animal models of refractory SE with their advantages and disadvantages. Notably, we also briefly review some of the hypotheses about drug resistance in SE that are well accepted in the field, and furthermore, put forward future perspectives for follow-up research on SE.

Clinico-Etiological Profile of Pediatric Refractory Status Epilepticus at a Public Hospital in India

BACKGROUND AND PURPOSE

Refractory status epilepticus (RSE) has been infrequently studied in Indian children. This research was conducted to study the clinico-etiological profiles and short-term outcomes of children aged 1 month to 12 years with convulsive RSE, at a public hospital.

METHODS

The study was conducted between 1st April 2016 and 28th February 2017 after receiving clearance from an Institutional Ethics Committee. All children (aged 1 month to 12 years) who presented to the pediatrics department of a tertiary-care public hospital with convulsive status epilepticus (SE), or who developed SE during their hospital stay, were enrolled. All patients were investigated and managed according to a standard protocol. Outcomes were assessed based on the Glasgow Outcome Scale. Details of children who progressed to RSE were compared to those without RSE.

RESULTS

Fifty children (28 males) with CSE were enrolled, of which 20 (40%) progressed to RSE. Central nervous system (CNS) infection was the most common etiology (53% in SE and 55% in RSE, p > 0.05). Non-compliance with anti-epileptic drugs was the second most common etiology. The overall mortality rate was 38%, and although the odds of death in RSE (50%) were higher than in SE (30%), this difference was not statistically significant (p = 0.15). The odds of having a poor outcome was six times higher in children with RSE as compared to those with SE (odds ratio, 6.0; 95% confidence interval, 1.6-22.3; p = 0.005).

CONCLUSIONS

When managing CNS infections, pediatricians need to be aware of the high risk of developing RSE. In addition, the possibility of RSE should be considered and managed promptly in an intensive-care setting, to reduce the mortality and morbidity of this severe neurological condition.

A Comparison of Intravenous Levetiracetam and Valproate for the Treatment of Refractory Status Epilepticus in Children

Because of the lack of studies comparing the efficacy and safety of levetiracetam and valproate before the induction of general anesthesia in the treatment of convulsive refractory status epilepticus in children, we aimed to compare the effectiveness of these antiepileptic drugs in patients with convulsive status epilepticus admitted to the Pediatric Intensive Care Unit between 2011 and 2014. Forty-six (59%) of the 78 patients received levetiracetam, and 32 (41%) received valproate for the treatment of refractory status epilepticus. The response rate was not significantly different between the 2 groups. Although no adverse event was noted in patients who received levetiracetam, 4 (12.5%) patients in the valproate group experienced liver dysfunction (P = .025). According to our results, levetiracetam and valproate may be used in the treatment of refractory status epilepticus before the induction of general anesthesia. Levetiracetam appears as effective as valproate, and also safer.

Management of Status Epilepticus in Children

Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children.

Continuous infusion, general anesthesia and other intensive care treatment for uncontrolled status epilepticus

PURPOSE OF REVIEW

To discuss the use of continuous infusions, general anesthesia, hypothermia, and ketogenic diet as treatment for uncontrolled status epilepticus in pediatric patients.

RECENT FINDINGS

Recent studies demonstrate that clinical practitioners have a hierarchy in approach in controlling refractory status epilepticus (RSE) and super-refractory status epilepticus in children. In the acute setting of RSE, midazolam achieves clinical seizure control at a mean of 41 min after starting an infusion. When midazolam has failed to control RSE, the evidence points to barbiturate anesthesia as the next frequently used option. When both midazolam and barbiturates have failed, use of isoflurane or ketamine anesthesia has been tried at a mean of 10 days after RSE onset, although the studies are largely anecdotal. Increasingly, the use of therapeutic hypothermia or ketogenic diet is described as a strategy for super-refractory status epilepticus, and better evidence for their use may become available from ongoing randomized studies.

SUMMARY

Uncontrolled episodes of status epilepticus require intensive care treatment and the literature describes a common pathway of care used by many. However, cases of truly refractory and super-refractory status epilepticus are seen infrequently at any given institution. One strategy to improve the quality of evidence is to develop prospective, national and multinational case registries to determine the range of presentations and causes, efficacy of treatments, and clinical outcomes.

Status epilepticus and refractory status epilepticus management

Status epilepticus (SE) describes persistent or recurring seizures without a return to baseline mental status and is a common neurologic emergency. SE can occur in the context of epilepsy or may be symptomatic of a wide range of underlying etiologies. The clinician's aim is to rapidly institute care that simultaneously stabilizes the patient medically, identifies and manages any precipitant conditions, and terminates seizures. Seizure management involves "emergent" treatment with benzodiazepines followed by "urgent" therapy with other antiseizure medications. If seizures persist, then refractory SE is diagnosed and management options include additional antiseizure medications or infusions of midazolam or pentobarbital. This article reviews the management of pediatric SE and refractory SE.

Pediatric status epilepticus management

PURPOSE OF REVIEW

This review discusses the management of status epilepticus in children, including both anticonvulsant medications and overall management approaches.

RECENT FINDINGS

Rapid management of status epilepticus is associated with a greater likelihood of seizure termination and better outcomes, yet data indicate that there are often management delays. This review discusses an overall management approach aiming to simultaneously identify and manage underlying precipitant causes, administer anticonvulsants in rapid succession until seizures have terminated, and identify and manage systemic complications. An example management pathway is provided.

SUMMARY

Status epilepticus is a common neurologic emergency in children and requires rapid intervention. Having a predetermined status epilepticus management pathway can expedite management.

Pediatric intensive care treatment of uncontrolled status epilepticus

The critically ill mechanically ventilated child with ongoing seizures that are refractory to any treatment presents a distinct challenge in pediatric neurocritical care. The evidence base from randomized controlled trials on which anti-epileptic drug (AED) strategy should be used is inadequate. This review of refractory and super-refractory status epilepticus summarizes recent pediatric case series regarding definitions, the second-tier AED therapies once initial anticonvulsants have failed, and the experience of high-dose midazolam, barbiturate anesthesia, and volatile anesthetics for uncontrolled status epilepticus.

Continuous infusion pentobarbital for refractory status epilepticus in children

The purpose of this retrospective medical chart review was to describe dosing regimens and outcomes in children who received continuous pentobarbital therapy for refractory status epilepticus. Thirty patients (age = 6.5 ± 5.1 years; 67% male) received a mean loading dose of 5.4 ± 2.8 mg/kg with an initial infusion of 1.1 ± 0.4 mg/kg/h. Maximum infusion dose was 4.8 ± 2 mg/kg/h. Thirty-three percent of patients achieved sustained burst suppression without relapse; 66.7% experienced relapse, but 60% of those (n = 12) eventually reachieved burst suppression. Children achieving burst suppression within 24 hours of pentobarbital initiation and those older than age 5 years were 1.5 times more likely to have a positive outcome. None of these variables, however, achieved significance (Fisher exact test). Ninety-three percent of patients required inotropes; 66% acquired an infection; 10% had metabolic acidosis; and 10% experienced pancreatitis. Poor outcomes (death, encephalopathy) were observed in 33% of patients.

Treatment of refractory convulsive status epilepticus in children: other therapies

Refractory convulsive status epilepticus occurs when seizures are not controlled with initial benzodiazepine therapy or a subsequent anticonvulsant drug. Typically drug-induced anesthesia is then pursued with midazolam or a barbiturate. This results in prolonged, intensive care, which requires meticulous attention to medical management to minimize complications. When seizures persist other options must be considered. These include (1) other medications, (2) surgery, (3) the ketogenic diet, (4) hypothermia, (5) inhalational anesthetic agents, and (6) immune modulating therapy. This review addresses the literature related to the use of the latter (4) treatment options. I will discuss the role of each treatment and review the evidence for it's use, along with possible side-effects.