Survivors and nonsurvivors of very prolonged status epilepticus

Staged treatment response in status epilepticus: Lessons from the SENSE registry

OBJECTIVES

Although in epilepsy patients the likelihood of becoming seizure-free decreases substantially with each unsuccessful treatment, to our knowledge this has been poorly investigated in status epilepticus (SE). We aimed to evaluate the proportion of SE cessation and functional outcome after successive treatment steps.

METHODS

We conducted a post hoc analysis of a prospective, observational, multicenter cohort (Sustained Effort Network for treatment of Status Epilepticus [SENSE]), in which 1049 incident adult SE episodes were prospectively recorded at nine European centers. We analyzed 996 SE episodes without coma induction before the third treatment step. Rates of SE cessation, mortality (in ongoing SE or after SE control), and favorable functional outcome (assessed with modified Rankin scale) were evaluated after each step.

RESULTS

SE was treated successfully in 838 patients (84.1%), 147 (14.8%) had a fatal outcome (36% of them died while still in SE), and 11 patients were transferred to palliative care while still in SE. Patients were treated with a median of three treatment steps (range 1-13), with 540 (54.2%) receiving more than two steps (refractory SE [RSE]) and 95 (9.5%) more than five steps. SE was controlled after the first two steps in 45%, with an additional 21% treated after the third, and 14% after the fourth step. Likelihood of SE cessation (p < 0.001), survival (p = 0.003), and reaching good functional outcome (p < 0.001) decreased significantly between the first two treatment lines and the third, especially in patients not experiencing generalized convulsive SE, but remained relatively stable afterwards.

SIGNIFICANCE

The significant worsening of SE prognosis after the second step clinically supports the concept of RSE. However, and differing from findings in human epilepsy, RSE remains treatable in about one third of patients, even after several failed treatment steps. Clinical judgment remains essential to determine the aggressiveness and duration of SE treatment, and to avoid premature treatment cessation in patients with SE.

Efficacy of topiramate as an add-on therapy in patients with refractory status epilepticus: a short systematic review

OBJECTIVE

To identify current evidence on the use of topiramate for refractory status epilepticus.

METHODS

We reviewed the literature to investigate the efficacy of topiramate in the treatment of refractory status epilepticus. The search terms used were "status epilepticus", "refractory", "treatment" and "topiramate". No restrictions were used.

RESULTS

The search yielded 487 articles that reported using topiramate as a treatment for refractory status epilepticus and its outcomes. Case reports, review articles, and animal experiments were excluded. After excluding duplicates and applying inclusion and exclusion criteria, nine studies were included for analyses. Descriptive and qualitative analyses were performed, and the results were as follows: response rates (defined as termination in-hospital until 72 hours after the administration of topiramate) varied from 27% to 100%. The mortality rate varied from 5.9% to 68%. Positive functional long-term outcomes, defined as discharge, back to baseline or rehabilitation, were documented by seven studies, and the rates ranged between 4% and 55%. Most studies reported no or mild adverse effects.

CONCLUSION

Topiramate was effective in terminating refractory status epilepticus, presented relatively low mortality and was well tolerated. Therefore, topiramate could be a good option as a third-line therapy for refractory status epilepticus, but further studies are necessary.

Acute Non-Convulsive Status Epilepticus after Experimental Traumatic Brain Injury in Rats

Severe traumatic brain injury (TBI) induces seizures or status epilepticus (SE) in 20-30% of patients during the acute phase. We hypothesized that severe TBI induced with lateral fluid-percussion injury (FPI) triggers post-impact SE. Adult Sprague-Dawley male rats were anesthetized with isoflurane and randomized into the sham-operated experimental control or lateral FPI-induced severe TBI groups. Electrodes were implanted right after impact or sham-operation, then video-electroencephalogram (EEG) monitoring was started. In addition, video-EEG was recorded from naïve rats. During the first 72 h post-TBI, injured rats had seizures that were intermingled with other epileptiform EEG patterns typical to non-convulsive SE, including occipital intermittent rhythmic delta activity, lateralized or generalized periodic discharges, spike-and-wave complexes, poly-spikes, poly-spike-and-wave complexes, generalized continuous spiking, burst suppression, or suppression. Almost all (98%) of the electrographic seizures were recorded during 0-72 h post-TBI (23.2 ± 17.4 seizures/rat). Mean latency from the impact to the first electrographic seizure was 18.4 ± 15.1 h. Mean seizure duration was 86 ± 57 sec. Analysis of high-resolution videos indicated that only 41% of electrographic seizures associated with behavioral abnormalities, which were typically subtle (Racine scale 1-2). Fifty-nine percent of electrographic seizures did not show any behavioral manifestations. In most of the rats, epileptiform EEG patterns began to decay spontaneously on Days 5-6 after TBI. Interestingly, also a few sham-operated and naïve rats had post-operation seizures, which were not associated with EEG background patterns typical to non-convulsive SE seen in TBI rats. To summarize, our data show that lateral FPI-induced TBI results in non-convulsive SE with subtle behavioral manifestations; this explains why it has remained undiagnosed until now. The lateral FPI model provides a novel platform for assessing the mechanisms of acute symptomatic non-convulsive SE and for testing treatments to prevent post-injury SE in a clinically relevant context.

The etiology and prognosis of super-refractory convulsive status epilepticus in children

BACKGROUND

Both refractory convulsive status epilepticus (SE) and super-refractory SE are medical emergencies. However, there are limited data on super-refractory SE in children. Thus, this study focuses on characterizing the demographics, outcomes, and prognostic factors for super-refractory SE in children.

METHODS

This study was a retrospective analysis of super-refractory SE treated in a tertiary referral center in Taiwan. The functional outcome was evaluated by modified Rankin scale (mRS). Significant functional decline was defined as an mRS difference (before hospital admission and at discharge) of more than 2. The variates and the follow-up mRS values were then analyzed statistically.

RESULTS

We enrolled 134 patients with 191 episodes of convulsive SE and identified 30 patients with 38 episodes of convulsive super-refractory SE. The incidence of convulsive super-refractory SE in the group with SE was 19.9%, and the age ranged from 2.5 months to 17 years. In-hospital mortality was 13.3%, which was much lower than that of adult cohorts. Newly acquired epilepsy and cognitive deficit occurred in 100% and 88.5%, respectively. Newly acquired epilepsy, as a sequel of super-refractory SE, was observed in all 18 patients (100%) who survived and had no history of epilepsy. Significant functional decline (mRS difference of more than 2) at discharge occurred in 76.7%. Poor functional outcome was associated with acute symptomatic etiology (P < 0.001) and the number of anesthetic agents (P = 0.002). The functional outcome improved after 1 year of follow-up in our population.

CONCLUSIONS

Super-refractory SE is associated with significant morbidity and mortality in children. However, the in-hospital mortality rate is much lower compared with adults. The functional outcome in children is associated with acute symptomatic etiology and the number of anesthetic agents and may improve after long-term follow-up.

Treatment of Refractory and Super-refractory Status Epilepticus

Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.

An update on the recognition and treatment of non-convulsive status epilepticus in the intensive care unit

INTRODUCTION

Non-convulsive status epilepticus (NCSE) is a complex and diverse condition which is often an under-recognised entity in the intensive care unit. When NCSE is identified the optimal treatment strategy is not always clear. Areas covered: This review is based on a literature review of the key literature in the field over the last 5-10 years. The articles were selected based on their importance to the field by the authors. Expert commentary: This review discusses the complex situations when a neurological consultation may occur in a critical care setting and provides an update on the latest evidence regarding the recognition of NCSE and the decision making around determining the aggressiveness of treatment. It also considers the ictal-interictal continuum of conditions which may be met with, particularly in the era of continuous EEG, and provides an approach for dealing with these. Suggestions for how the field will develop are discussed.

Is Favorable Outcome Possible After Prolonged Refractory Status Epilepticus?

When status epilepticus (SE) remains refractory to appropriate therapy, it is associated with high mortality and with substantial morbidity in survivors. Many outcome predictors such as age, seizure type, level of consciousness before treatment, and mostly, etiology, are well-established. A longer duration of SE is often associated with worse outcome, but duration may lose its prognostic value after several hours. Several terms and definitions have been used to describe prolonged, refractory SE, including "malignant SE," "prolonged" SE, and more recently, "super refractory" SE, defined as "SE that has continued or recurred despite 24 hours of general anesthesia (or coma-inducing anticonvulsants)." There are few data available regarding the outcome of prolonged refractory SE, and even fewer for SE remaining refractory to anesthetic drugs. This article reviews reports of outcome after prolonged, refractory, and "super refractory" SE. Most information detailing the clinical outcome of patients surviving these severe illnesses, in which seizures can persist for days or weeks (and especially those concerning "super-refractory" SE) come from case reports and retrospective cohort studies. In many series, prolonged, refractory SE has a mortality of 30% to 50%, and several studies indicate that most survivors have a substantial decline in functional status. Nevertheless, several reports demonstrate that good functional outcome is possible even after several days of SE and coma induction. Treatment of refractory SE should not be withdrawn from younger patients without structural brain damage at presentation solely because of the duration of SE.

Clinical outcomes following prolonged refractory status epilepticus (PRSE)

BACKGROUND

To define the clinical profile and outcome of patients in prolonged refractory status epilepticus (PRSE), and investigate possible predictors of outcome.

METHODS

We reviewed 63 consecutive patients with PRSE cared for in the medical and neurointensive care units of three academic medical centers over a 9-year period. For this multi-center retrospective cohort study, PRSE was defined as SE that persisted despite at least 1 week of induced coma. Variables examined for their relationship to outcome included etiology, EEG, neuroimaging, and age.

RESULTS

Forty-two (66%) of 63 patients in PRSE survived to discharge from hospitalization. Fourteen (22%) patients had a good outcome (mRS ≤ 3) at last available follow up (at least 6 months post-PRSE). Of these, 6 (10%) individuals had no significant disability and were able to carry out all usual activities (mRS = 1). Normal neuroimaging and a reactive EEG at onset of PRSE were associated with good outcome. Good or excellent clinical outcomes were possible in patients in PRSE for up to 79 days, and in patients up to 69 years old.

CONCLUSIONS

Good outcome is not unusual in PRSE, including in some older patients, in a variety of diagnoses, and despite months of coma.

Status epilepticus and the use of continuous EEG monitoring in the intensive care unit

PURPOSE OF REVIEW

Status epilepticus (SE) is one of the major neurologic emergencies. Newer data about the genesis and treatment of this condition are available to help improve our understanding and management.

RECENT FINDINGS

Approximately 150,000 cases of generalized convulsive SE occur in the United States each year. Clinically apparent seizures complicate about 8% of intensive care unit admissions, and another 10% of ICU patients suffer electrographic seizures in the course of another critical illness. Some of these cases result from previously under-recognized epileptogenic effects of commonly used drugs, such as cefepime. Continuous EEG (cEEG) recording is necessary for both diagnosis and management in these patients, especially since anticonvulsant drugs may abolish motor activity without stopping seizures. Recent studies have underscored the utility of benzodiazepines as the first-line agents for SE termination. The recently published Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) demonstrates that the more rapidly treatment is administered, the more effective it will be. When SE fails to respond to usual doses of benzodiazepines, it should be considered refractory to conventional anticonvulsants, and a general anesthetic approach is likely to be necessary.

SUMMARY

While definitions have varied, patients should be managed for SE after 5 minutes of seizure activity. Management of a patient with SE involves three phases: termination of SE, prevention of recurrence, and treatment of complications. The typical anticonvulsants have limited ability to terminate SE; lorazepam is the most useful, controlling SE in 65% of patients experiencing generalized convulsive SE. If the first conventional anticonvulsant fails, others are unlikely to be useful, and one of the newer anticonvulsants or a general anesthetic agent should be considered. EEG is crucial in the diagnosis and classification of potential seizures. cEEG monitoring helps to guide anticonvulsant therapy in patients with SE and those with frequent seizures. In addition, cEEG has the potential for presymptomatic diagnosis of delayed neurologic deterioration in patients with subarachnoid hemorrhage and for the differential diagnosis of stroke subtypes, especially when cEEG is subjected to signal processing.