Review and Updates on the Treatment of Refractory and Super Refractory Status Epilepticus

Ketamine reduces seizure and interictal continuum activity in refractory status epilepticus: a multicenter in-person and teleneurocritical care study

BACKGROUND

There is not a preferred medication for treating refractory status epilepticus (RSE) and intravenous ketamine is increasingly used. Ketamine efficacy, safety, dosage, and influence of other variables on seizure cessation while on ketamine infusions are not well studied. We aimed to characterize ketamine effect on RSE, including interictal activity on electroencephalogram (EEG) and when done by Teleneurocritical care (TNCC).

METHODS

We conducted a multicenter, retrospective study from August 2017 to October 2022. Patients 18 years or older who had RSE and received ketamine were included. The primary outcome was effect of ketamine on RSE including interictal activity; secondary outcomes were effect of other variables on RSE, care by TNCC, ketamine infusion dynamics, adverse events, and discharge outcomes. Logistic regression was used.

RESULTS

Fifty-one patients from five hospitals met inclusion criteria; 30 patients had RSE and interictal activity on EEG. Median age was 56.8 years (IQR 18.2) and 26% had previously diagnosed epilepsy. Sixteen (31%) patients were treated virtually by TNCC. In those with RSE on EEG, ketamine was added as the fourth antiseizure medication (mean 4.4, SD 1.6). An initial bolus of ketamine was used in 24% of patients (95 mg, IQR 47.5), the median infusion rate was 30.8 mcg/kg/min (IQR 40.4), and median infusion duration was 40 h (IQR 37). Ketamine was associated with 50% cessation of RSE and interictal activity at 24 h in 84% of patients, and complete seizure cessation in 43% of patients. In linear regression, ASMs prior to ketamine were associated with seizure cessation (OR 2.6, 95% CI 0.9-6.9, p = 0.05), while the inverse was seen with propofol infusions (OR 0.02, 95% CI 0.001-0.43, p = 0.01). RSE management by in-person NCC versus virtual by TNCC did not affect rates of seizure cessation.

CONCLUSIONS

Ketamine infusions for RSE were associated with reduced seizure burden at 24 h, with 84% of patients having 50% seizure reduction. Similar efficacy and safety was observed irrespective of underlying RSE etiology or when done via TNCC vs in-person NCC.

Ketamine for Super-Refractory Status Epilepticus in Palliative Care. A Case Report and Review of the Literature

We report a case of super refractory status epilepticus uncontrolled by multiple anti-seizure medications in an individual with acute liver failure due to hepatic cirrhosis and an obstructive ileocecal mass plus multiple bilateral lung lesions presumed to be metastatic. A ketamine infusion was initiated late in his hospitalization which eliminated the convulsive seizures in less than an hour. The abatement of convulsive seizures allowed his grieving wife to return to her husband's bedside to witness the withdrawal of life sustaining treatment and be present during the final 24 hours of his life. We review the medical literature on the role of Intravenous (IV) Ketamine in the treatment of super refractory status epilepticus.

Utilization of the ketogenic diet for adults with status epilepticus

BACKGROUND

The ketogenic diet (KD) is a high-fat, low-carbohydrate diet with therapeutic potential in refractory seizures, both in outpatient and inpatient settings. Successful implementation of KD involves a multifaceted, interdisciplinary approach to address anticipated challenges. We sought to characterize the utilization of KD among healthcare providers caring for adults with status epilepticus (SE).

METHODS

We distributed a web-based survey through professional societies, including the American Academy of Neurology (AAN), Neurocritical Care Society (NCS), American Epilepsy Society (AES), Neuro Anesthesia and Critical Care Society (NACCS), and the Academy of Nutrition and Dietetics (AND), and via research contacts. We asked respondents about practice experience and experience using KD as a treatment for SE. Descriptive statistics and Chi-square tests were used to analyze the results.

RESULTS

Of 156 respondents, 80% of physicians and 18% of non-physicians reported experience with KD for SE. Anticipated difficulty in achieving ketosis (36.3%), lack of expertise (24.2%), and lack of resources (20.9%) were identified as the most important barriers limiting the utilization of KD. The absence of dietitians (37.1%) or pharmacists (25.7%) support was the most important missing resource. Reasons for stopping KD included perceived ineffectiveness (29.1%), difficulty achieving ketosis (24.6%), and side effects (17.3%). Academic centers had more experience with the use of KD and greater EEG monitoring availability and fewer barriers to its implementation. The need for randomized clinical trials supporting efficacy (36.5%) and better practice guidelines for implementation and maintenance of KD (29.6%) were cited most frequently as factors to increase utilization of KD.

CONCLUSION

This study identifies important barriers to the utilization of KD as a treatment for SE despite evidence supporting its efficacy in the appropriate clinical context, namely lack of resources and interdisciplinary support, and lack of established practice guidelines. Our results highlight the need for future research to improve understanding of the efficacy and safety of KD along with better interdisciplinary collaborations to increase its utilization.

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.

Factors associated with mortality in patients with super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is a critical condition in which seizures persist despite anesthetic use for 24 h or longer. High mortality has been reported in patients with SRSE, but the cause of death remains unclear. We investigated the factors associated with mortality, including clinical characteristics, SE etiologies and severities, treatments, and responses in patients with SRSE in a 13-year tertiary hospital-based retrospective cohort study comparing these parameters between deceased and surviving patients. SRSE accounted for 14.2% of patients with status epilepticus, and 28.6% of SRSE patients died. Deceased patients were mostly young or middle-aged without known systemic diseases or epilepsy. All deceased patients experienced generalized convulsive status epilepticus and failure of anesthetic tapering-off, significantly higher than survivors. An increased number of second-line anesthetics besides midazolam was observed in the deceased (median, 3, interquartile range 2–3) compared to surviving (1, 1–1; p = 0.0006) patients with prolonged use durations (p = 0.047). For mortality, the cut-off number of second-line anesthetics was 1.5 (AUC = 0.906, p = 0.004). Deceased patients had significantly higher renal and cardiac complications and metabolic acidosis than survivors. In SRSE management, multi-anesthetic use should be carefully controlled to avoid systemic complications and mortality.

Chinese expert recommendations on ketogenic diet therapy for super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is a serious and life-threatening neurological condition. Ketogenic diet (KD) is a diet characterized by high fat, low carbohydrate, and moderate protein. As KD shows effectiveness in controlling seizures in more than half of SRSE patients, it can be a treatment option for SRSE. Currently, KD treatment for SRSE is based on personal experience and observational evidence has been published. In the context of a lack of a validated guideline, we convened a multicenter expert panel within the China Association Against Epilepsy (CAAE) Ketogenic Diet Commission to work out the Chinese expert recommendations on KD for SRSE. We summarize and discuss the latest clinical practice of KD for SRSE in critical care settings. Recommendations are given on patient selection, the timing of KD, diet implementation, and follow-up. More research data are needed in this area to support better clinical practice.

The role of ketamine-induced beta activity in the treatment of refractory status epilepticus. Is the EEG useful to determine responder's rate? A retrospective study

INTRODUCTION

Multiple investigations have been done to evaluate the possible effect of ketamine in the treatment of status epilepticus (SE).

OBJECTIVES

To evaluate the electrographic effect of ketamine on EEG, and its clinical utility following-up refractory and super refractory status epilepticus (SRSE).

METHODS

Retrospective review of 24 patients with SE. Clinical record and Video-electroencephalogram (video-EEG) of all included patients were reviewed. The patients' EEGs were then monitored for any immediate changes after administration of the first dose of ketamine as well as at the time patients would be predicted to have peak serum concentration of ketamine. Patients with cessation of electrographic seizures and no SE recurrence within the same admissions were categorized as "Responders". Statistical differences between qualitative variables were analyzed using chi square test. Differences between median were analyzed by Mann-Whitney U test. Difference between groups were considered significant when p < 0.05.

RESULTS

We identified 24 patients with SE. Twelve out of 24 (50%) had SRSE and 12 out of 24 (50%) had refractory status epilepticus (RSE). The appearance of superimposed beta activity after ketamine was initiated was associated with a higher responder rate (100% versus 33.3% in the responder group versus the non-responder group respectively). Notably, the presence of a burst suppression pattern had no significant association with one group compared to the other (41.6% versus 33.3%, in the responder group vs the non-responder group respectively).

CONCLUSIONS

Background superimposed beta activity induced by ketamine is an early and reliable EEG finding associated with status epilepticus termination.