New-onset refractory status epilepticus treated with vagus nerve stimulation: A case report

Responsive neurostimulation as a therapy for epilepsy following new-onset refractory status epilepticus: Case series and review of the literature

OBJECTIVE

To report clinical outcomes of patients who presented with new-onset refractory status epilepticus (NORSE), developed drug-resistant epilepsy (DRE), and were treated with responsive neurostimulation (RNS).

METHODS

We performed a retrospective review of patients implanted with RNS at our institution and identified three who originally presented with NORSE. Through chart review, we retrieved objective and subjective information related to their presentation, workup, and outcomes including patient-reported seizure frequency. We reviewed electrocorticography (ECoG) data to estimate seizure burden at 3, 6, 12, and 24 months following RNS implantation. We performed a review of literature concerning neurostimulation in NORSE.

RESULTS

Use of RNS to treat DRE following NORSE was associated with reduced seizure burden and informed care by differentiating epileptic from non-epileptic events.

CONCLUSIONS

Our single-center experience of three cases suggests that RNS is a safe and potentially effective treatment for DRE following NORSE.

SIGNIFICANCE

This article reports outcomes of the largest case series of NORSE patients treated with RNS. Since patients with NORSE are at high risk of adverse neuropsychiatric and cognitive sequelae beyond seizures, a unique strength of RNS over other surgical options is the ability to distinguish ictal or peri-ictal from non-epileptic events.

Surgical management of status epilepticus: A systematic review

Status Epilepticus (SE), unresponsive to medical management, is associated with high morbidity and mortality. Surgical management is typically considered in these refractory cases. The best surgical approach for affected patients remains unclear; however, given the lack of controlled trials exploring the role of surgery. We performed a systematic review according to PRIMSA guidelines, including case reports and series describing surgical interventions for patients in SE. Cases (157 patients, median age 12.9 years) were followed for a median of 12 months. Patients were in SE for a median of 21 days before undergoing procedures including: focal resection (36.9%), functional hemispherectomy (21%), lobar resection (12.7%), vagus nerve stimulation (VNS) (12.7%), deep brain stimulation (DBS) (6.4%), multiple subpial transection (MST) (3.8%), responsive neurostimulation (RNS) (1.9%), and cortical stimulator placement (1.27%), with 24 patients undergoing multiple procedures. Multiple SE semiologies were identified. 47.8% of patients had focal seizures, and 65% of patients had focal structural abnormalities on MRI. SE persisted for 36.8 ± 47.7 days prior to surgical intervention. SE terminated following surgery in 81.5%, terminated with additional adjuncts in 10.2%, continued in 1.9%, and was not specified in 6.4% of patients. Long-term seizure outcomes were favorable, with the majority improved and 51% seizure-free. Eight patients passed away in follow-up, of which three were in SE. Seizures emerging from one hemisphere were both more likely to immediately terminate (OR 4.7) and lead to long-term seizure-free status (OR 3.9) compared to nonunilateral seizures. No other predictors, including seizure focality, SE duration, or choice of surgical procedure, were predictors of SE termination. Surgical treatment of SE can be effective in terminating SE and leading to sustained seizure freedom, with many different procedures showing efficacy if matched appropriately with SE semiology and etiology. PLAIN LANGUAGE SUMMARY: Patients with persistent seizures (Status Epilepticus) that do not stop following medications can be treated effectively with surgery. Here, we systematically review the entirety of existing literature on surgery for treating status epilepticus to better identify how and when surgery is used and what patients do after surgery.

Refractory status epilepticus arrested by vagus nerve stimulation

A 54-year-old man developed altered mental state and generalised tonic-clonic seizures after 1 week of upper respiratory tract symptoms and diarrhoea, having been previously well. His MR scan of brain showed multifocal progressive T2 cortical signal changes. He was diagnosed with new-onset refractory status epilepticus (NORSE), initially treated as being secondary to autoimmune/paraneoplastic limbic encephalitis, although subsequent investigations were negative. His seizures and electrographic epileptiform activity continued despite escalating doses of antiseizure medications, immunosuppression with corticosteroids, immunoglobulins, plasma exchange and rituximab, and thereafter anaesthetic agents. A vagus nerve stimulator (VNS) was implanted 6 weeks after admission and its voltage rapidly increased over 4 days; his seizure activity resolved in the third week after VNS implantation. This case highlights the role of VNS in the early management of NORSE.

Role of Vagus Nerve Stimulation in Refractory and Super Refractory Status Epilepticus: A Pediatric Case Series

BACKGROUND

Status epilepticus is a life-threatening condition that is defined as refractory (RSE) when the seizure activity continues despite treatment with benzodiazepine and a second appropriate treatment. Super refractory status epilepticus (SRSE) is an RSE that persists or recurs for ≥24 h. Few papers have reported the outcomes of pediatric patients affected by RSE and SRSE and treated with neuromodulation therapies. Vagus nerve stimulation (VNS) is an approved treatment for drug-resistant epilepsy. We present our findings of pediatric patients treated with VNS for RSE/SRSE.

METHODS

We present a case series of seven consecutive pediatric patients treated with VNS for SRSE since 2012 by a single surgeon in Monza and Padua. A rapid titration was started soon after implantation. We considered electroclinical data before and after VNS implantation and at the last follow-up.

RESULTS

We achieved the resolution of SRSE in five out of seven patients in a mean time of two weeks. At the last follow-up, these patients had a significant reduction of seizure burden without any relapse of SE.

DISCUSSION AND CONCLUSIONS

Based on our limited findings, we discuss the potential role of VNS therapy in similar but distinct clinical contexts. For patients with drug-resistant epilepsy and RSE/SRSE, prompt VNS consideration is suggested, offering rapid responses and potentially reducing pharmacological load. Meanwhile, in NORSE/FIRES, we suggest early neuromodulation during the acute phase if standard treatments prove ineffective or not tolerated. This approach may leverage VNS's potential anti-inflammatory effects and neuromodulation, enhancing patient-specific treatments. Expanding case studies and prolonged follow-ups are recommended to strengthen these clinical insights.

Neuromodulation in new-onset refractory status epilepticus

Background

New-onset refractory status epilepticus (NORSE) and its subset of febrile infection-related epilepsy syndrome (FIRES) are devastating clinical presentations with high rates of mortality and morbidity. The recently published consensus on the treatment of these conditions includes anesthetics, antiseizure drugs, antivirals, antibiotics, and immune therapies. Despite the internationally accepted treatment, the outcome remains poor for a significant percentage of patients.

Methods

We conducted a systematic review of the use of neuromodulation techniques in the treatment of the acute phase of NORSE/FIRES using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

Our search strategy brought up 74 articles of which 15 met our inclusion criteria. A total of 20 patients were treated with neuromodulation. Thirteen cases represented FIRES and in 17 cases the NORSE remained cryptogenic. Ten had electroconvulsive therapy (ECT), seven had vagal nerve stimulation (VNS), and four had deep brain stimulation (DBS); one patient had initially VNS and later DBS. Eight patients were female and nine were children. In 17 out of 20 patients, the status epilepticus was resolved after neuromodulation, while three patients died.

Conclusion

NORSE can have a catastrophic course and the first treatment goal should be the fastest possible termination of status epilepticus. The data presented are limited by the small number of published cases and the variability of neuromodulation protocols used. However, they show some potential clinical benefits of early neuromodulation therapy, suggesting that these techniques could be considered within the course of FIRES/NORSE.

Safe and effective implantation and use of vagal nerve stimulation in new-onset refractory status epilepticus in early pregnancy: a case report

Introduction

The management of new-onset refractory status epilepticus (NORSE) in pregnancy may be complicated by anti-seizure medication (ASM) polytherapy-associated teratogenicity. We aim to demonstrate the safety and efficacy of vagal nerve stimulation (VNS) in a pregnant patient presenting with NORSE.

Case description

A 30-year old female, at 5-weeks' gestation presented with drug-refractory myoclonic status epilepticus, responsive only to high levels of anesthetic agents. The severity of seizures did not allow extubation, and the patient remained ventilated and sedated. VNS was implanted 26 days after seizure onset. The immediate post-operative output was 0.25 mA, which was rapidly titrated up to 0.5 mA the next morning, and to 0.75 mA that afternoon. This was further increased to 1.0 mA on 3rd day post-operation, and to 1.25 mA 7 days post-op. Myoclonic jerks diminished significantly 7 days post-op, allowing extubation. Twenty days after VNS implantation, no myoclonic jerks were observed. There was also a notable neurological improvement including increased alertness and mobility, and ability to obey commands. Drug overdose was subsequently found to be the most likely etiology of her NORSE. An early pregnancy assessment 17 days after VNS implantation showed a normally sited pregnancy, normal fetal heart activity and crown-rump length. The patient remained seizure free, gained functional independence and delivered a premature but otherwise healthy baby at 33 weeks' gestation.

Conclusion

NORSE is challenging to manage, further compounded in pregnancy due to the teratogenicity of ASMs and ASM polytherapy. This is the first case-study to report the safe implantation and use of VNS during the first trimester of pregnancy for the management of NORSE.

Perspective: Vagal nerve stimulation in the treatment of new-onset refractory status epilepticus

Introduction

Resistance to drug therapy is a major hurdle in new-onset refractory status epilepticus (NORSE) treatment and there is urgent need to develop new treatment approaches. Non-drug approaches such as neuromodulation offer significant benefits and should be investigated as new adjunct treatment modalities. An important unanswered question is whether desynchronizing networks by vagal nerve stimulation (VNS) may improve seizure control in NORSE patients.

Main text

We present a summary of published NORSE cases treated with VNS and our own data, discuss possible mechanisms of action, review VNS implantation timing, stimulation setting titration protocols and outcomes. Further, we propose avenues for future research.

Discussion

We advocate for consideration of VNS for NORSE both in early and late stages of the presentation and hypothesize a possible additional benefit from implantation in the acute phase of the disease. This should be pursued in the context of a clinical trial, harmonizing inclusion criteria, accuracy of documentation and treatment protocols. A study planned within our UK-wide NORSE-UK network will answer the question if VNS may confer benefits in aborting unremitting status epilepticus, modulate ictogenesis and reduce long-term chronic seizure burden.

Combined Responsive Neurostimulation and Focal Resection for Super Refractory Status Epilepticus: A Systematic Review and Illustrative Case Report

OBJECTIVE

Super-refractory status epilepticus (SRSE) is a neurologic emergency with high mortality and morbidity. Although medical algorithms typically are effective, when they do fail, options may be limited, and neurosurgical intervention should be considered.

METHODS

We report a case of SRSE treated acutely with responsive neurostimulation (RNS) and focal surgical resection after intracranial monitoring. We also conducted a systematic review of the literature for neurosurgical treatment of SRSE (e.g., neurostimulation). Only published manuscripts were considered.

RESULTS

Our patient's seizure semiology consisted of left facial twitching with frequent evolution to bilateral tonic-clonic convulsions. Stereoelectroencephalography and grid monitoring identified multiple seizure foci. The patient underwent right RNS placement with cortical strip leads over the lateral primary motor and premotor cortex as well as simultaneous right superior temporal and frontopolar resection. Status epilepticus resolved 21 days after surgical resection and placement of the RNS. The systematic review revealed 15 case reports describing 17 patients with SRSE who underwent acute neurosurgical intervention. There were 3 patients with SRSE with RNS placement as a single modality, all of whom experienced cessation of SE. Four patients with SRSE received vagus nerve stimulation (3 as a single modality and 1 with combined corpus callosotomy), of whom 1 had SE recurrence at 2weeks. Two patients with SRSE received deep brain stimulation, and the remaining 8 underwent surgical resection; none had recurrence of SE.

CONCLUSIONS

RNS System placement with or without resection can be a viable treatment option for select patients with SRSE. Early neurosurgical intervention may improve seizure outcomes and reduce complications.

Long-term outcomes after NORSE: Treatment with vagus nerve stimulation

New-onset refractory status epilepticus (NORSE) is associated with high mortality, therapy-resistant epilepsy (TRE), and poor cognitive and functional outcomes. Some patients develop multifocal TRE, for whom surgery with a curative intention, is not an option. In these patients, vagus nerve stimulation (VNS) is performed as a palliative treatment. We report the long-term outcomes regarding seizure frequency, functional and cognitive outcome, and effectiveness of VNS in two patients with TRE as a consequence of NORSE. In the first patient with cryptogenic NORSE, VNS implantation occurred during the acute stage, probably contributing to the cessation of her status epilepticus. However, in the long-term follow-up, the patient persisted with daily multifocal seizures. In the second patient, VNS implantation was delayed to manage his epilepsy when the NORSE, ultimately due to autoimmune encephalitis, had resolved. During long-term follow-up, no reduction in seizure frequency was achieved. This evidence supporting the use of VNS in patients with TRE after NORSE warrants further investigation.

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) incl. Febrile Infection-Related Epilepsy Syndrome (FIRES): Statements and Supporting Evidence

OBJECTIVE

To develop consensus-based recommendations for the management of adult and paediatric patients with NORSE/FIRES based on best evidence and experience.

METHODS

The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater or equal to 7, and inappropriate if the median score was less than or equal to 3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey.

RESULTS

Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article.

SIGNIFICANCE

This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

Neuromodulation in Super-refractory Status Epilepticus

SUMMARY

Status epilepticus (SE) is a severe condition that needs immediate pharmacological treatment to tackle brain damage and related side effects. In approximately 20% of cases, the standard treatment for SE does not control seizures, and the condition evolves to refractory SE. If refractory status epilepticus lasts more than 24 hours despite the use of anesthetic treatment, the condition is redefined as super-refractory SE (srSE). sRSE is a destructive condition, potentially to cause severe brain damage. In this review, we discuss the clinical neuromodulation techniques for controlling srSE when conventional treatments have failed: electroconvulsive therapy, vagus nerve stimulation, transcranial magnetic stimulation, and deep brain stimulation. Data show that neuromodulation therapies can abort srSE in >80% of patients. However, no randomized, prospective, and controlled trials have been completed, and data are provided only by retrospective small case series and case reports with obvious inclination to publication bias. There is a need for further investigation into the use of neuromodulation techniques as an early treatment of srSE and to address whether an earlier intervention can prevent long-term complications.

Understanding new-onset refractory status epilepticus from an immunological point of view

New-onset refractory status epilepticus (NORSE) is unexpected onset of refractory status epilepticus in individuals with no preexisting relevant neurologic condition. The etiologies remain largely cryptogenic; treatment is challenging after failure to control seizures despite use of multiple antiepileptic drugs and anesthetic agents. Frequent fever and other infectious prodromes, elevated proinflammatory cytokine/chemokine levels, and limbic or multifocal brain lesions indicate active inflammation in NORSE. Among identified causes, autoimmune encephalitis is the most common and accounts for more than one-third of all known NORSE cases, followed by infection-related etiologies. Although more evidence is needed, anti-cytokine therapies with tocilizumab and anakinra along with other immunotherapeutic agents used in autoimmune encephalitis can aid in alleviating or hindering the inflammatory cascade and controlling seizures.

VNS Stopping Anti-NMDA Receptor Encephalitis-Triggered Nonconvulsive Status Epilepticus

BACKGROUND

Anti-NMDA receptor encephalitis (ANRE) is a rare autoimmune neurologic disorder characterized by encephalitis and a constellational of symptoms, including seizures, psychiatric disturbances, autonomic instability, and respiratory insufficiency. It is caused by the anti-NMDA receptor antibody. The most common etiologies for ANRE include malignancy and infection. Ovarian teratoma is the most commonly associated malignancy.

CASE DESCRIPTION

We describe the first reported case to our knowledge of ovarian teratoma causing ANRE resulting in nonconvulsive status epilepticus (NCSE), which was terminated with vagus nerve stimulation (VNS).

CONCLUSIONS

This case report provides a temporal correlation suggesting that VNS significantly altered the natural history of this patient's NCSE-ANRE. As more data are collected, and the VNS treatment modality more liberally used to treat NCSE, especially in the situation of ANRE, stronger layers of evidence will emerge to fill the gaps of understanding beyond this case report.

Brain-responsive neurostimulation treatment in patients with GAD65 antibody-associated autoimmune mesial temporal lobe epilepsy

Glutamic acid decarboxylase 65‐kilodalton isoform (GAD65) antibodies have been associated with multiple nonneurological and neurological syndromes including autoimmune epilepsy (AE). Although immunotherapy remains the cornerstone for the treatment of AE, those with GAD65 Ab‐associated AE (GAD65‐AE) remain refractory to immunotherapy and antiseizure medication (ASM). Outcomes of epilepsy surgery in this patient population have also been unsatisfactory. The role of neuromodulation therapy, particularly direct brain‐responsive neurostimulation therapy, has not been previously examined in GAD65‐AE. Here, we describe four consecutive patients with refractory GAD‐65‐associated temporal lobe epilepsy (GAD65‐TLE) receiving bilateral hippocampal RNS System treatment. The RNS System treatment was well tolerated and effective in this study cohort. Three patients had a >50% clinical seizure reduction, and one patient became clinically seizure‐free following resective surgery informed by the RNS System data with continued RNS System treatment. In all four of our patients, the long‐term ambulatory data provided by the RNS System allowed us to gain objective insights on electrographic seizure lateralization, patterns, and burden as well as guided immunotherapy and ASM optimization. Our results suggest the potential utility of the RNS System in the management of ASM intractable GAD65‐AE.

Vagus nerve stimulation in refractory and super-refractory status epilepticus - A systematic review

RATIONALE

Refractory status epilepticus (RSE) is the persistence of status epilepticus despite second-line treatment. Super-refractory SE (SRSE) is characterized by ongoing status despite 48 h of anaesthetic treatment. Due to the high case fatality in RSE of 16-39%, off label treatments without strong evidence of efficacy in RSE are often administered. In single case-reports and small case series totalling 28 patients, acute implantation of VNS in RSE was associated with 76% and 26% success rate in generalized and focal RSE respectively. We performed an updated systematic review of the literature on efficacy of VNS in RSE/SRSE by including all reported patients.

METHODS

We systematically searched EMBASE, CENTRAL, Opengre.eu, and ClinicalTrials.gov, and PubMed databases to identify studies reporting the use of VNS for RSE and/or SRSE. We also searched conference abstracts from AES and ILAE meetings.

RESULTS

45 patients were identified in total of which 38 were acute implantations of VNS in RSE/SRSE. Five cases had VNS implantation for epilepsia partialis continua, one for refractory electrical status epilepticus in sleep and one for acute encephalitis with refractory repetitive focal seizures. Acute VNS implantation was associated with cessation of RSE/SRSE in 74% (28/38) of acute cases. Cessation did not occur in 18% (7/38) of cases and four deaths were reported (11%); all of them due to the underlying disease and unlikely related to VNS implantation. Median duration of the RSE/SRSE episode pre and post VNS implantation was 18 days (range: 3-1680 days) and 8 days (range: 3-84 days) respectively. Positive outcomes occurred in 82% (31/38) of cases.

CONCLUSION

VNS can interrupt RSE and SRSE in 74% of patients; data originate from reported studies classified as level IV and the risk for reporting bias is high. Further prospective studies are warranted to investigate acute VNS in RSE and SRSE.

Neuromodulation techniques for status epilepticus: A review

BACKGROUND

Electroconvulsive therapy (ECT), Vagal Nerve Stimulation (VNS), Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS) are neuromodulation therapies that have been used to treat Status Epilepticus (SE).

OBJECTIVE

Review the literature about the efficacy and safety of neuromodulation therapies in SE in humans.

METHODS

We searched studies in PubMed, Scopus, Google Scholar and Science Direct (inception to June 2018). Four review authors independently selected the studies, extracted data and assessed the methodological quality of the studies using the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions, PRISMA guidelines, Oxford and GRADE scales, and Murad et al., 2018 methodological quality and synthesis of case series and case reports.

RESULTS

We analyzed 27 articles (45 patients) with 4 different neuromodulation therapies. In ECT we found 80% rate of disruption of SE and 5% of adverse events was reported. Using iVNS 15/16 (93.7%) patients resolved the SE. All patients who underwent TMS and DBS aborted SE, however, 50% of patients with DBS had severe adverse events.

CONCLUSIONS

Case series and case reports suggest that neuromodulation therapies can abort SE in 80-100% of patients (Oxford scale and GRADE were level 4 and D) with a wide range of adverse effects, which claims for prospective studies on the relationship be-tween efficacy and safety.

Vagus Nerve Stimulation (VNS) in Super Refractory New Onset Refractory Status Epilepticus (NORSE)

The treatment protocol of status epilepticus has many associated toxicities so there is interest in alternate nonmedicinal therapies for managing New Onset Refractory Status Epilepticus (NORSE) patients. Vagus nerve stimulation (VNS) is an FDA-approved therapy for refractory epilepsy that has been shown to decrease the frequency and severity of seizures. We present the case of a patient with new-onset refractory status epilepticus (NORSE) whose seizures were successfully treated with vagus nerve stimulation. A 25-year-old male with no history of epilepsy or other neurological disorders presented with altered mental status and generalized tonic-clonic seizures following a two-week history of an upper respiratory tract infection. Lumbar puncture showed neutrophilic pleocytosis, and he was treated for bacterial and viral meningoencephalitis. In spite of treatment, his seizures began increasing in frequency. On day three, the patient entered status epilepticus (SE) refractory to intensive pharmacotherapy with maximal doses of valproate, levetiracetam, and propofol. On day four, SE remained refractory, so pentobarbital was introduced with targeted burst suppression pattern on electroencephalography (EEG). Patient continued to be refractory to these measures, so a vagus nerve stimulator (VNS) was implanted (day eight). Following VNS implantation, EEG demonstrated significant reduction of seizure activity and subsequent magnet swiping continued aborting electrographic seizures. No SE or electrographic seizures were reported for seventy-two hours, but few occasional discharges were reported. Seizures eventually recurred on day fourteen and the patient succumbed to his multiple comorbidities on day seventeen. Due to the efficacy of VNS in refractory epilepsy, there was interest in using it in refractory status epilepticus. Multiple case reports have described a benefit from implantation of VNS in the treatment of SE. The successful use of VNS to acutely terminate status epilepticus for seventy-two hours in this critically ill patient adds to current evidence that there is utility in using VNS for refractory status epilepticus.

A favorable outcome of intensive immunotherapies for new-onset refractory status epilepticus (NORSE)

Background

New-onset refractory status epilepticus (NORSE) is a newly defined critical disease entity characterized by prolonged periods of refractory epileptic seizure with no readily identifiable cause in otherwise healthy individuals. Its etiology is uncertain, but autoimmune encephalitis is a possible candidate for the underlying cause of this condition. Immunotherapies could be considered for this condition, but its efficacy is not established.

Case presentation

A 31-year-old man with no prior history presented with refractory status epilepticus. His seizure persisted even with multiple anti-epileptic drugs and required prolonged general anesthesia under mechanical ventilation. Magnetic resonance imaging and cerebrospinal fluid did not indicate the cause of seizure, and autoantibodies related to encephalitis were not detected. It was speculated that the patient had occult autoimmune encephalopathy because of its acute-onset clinical course preceded by fever, even without definite evidence of an autoimmune mechanism. The patient received intravenous methylprednisolone, plasma exchange, and intravenous immunoglobulin in succession and manifested a favorable outcome after these treatments.

Conclusion

Our case supports the efficacy of immunotherapies for NORSE even though it does not manifest definite evidence for autoimmune background. Clinicians should consider these immunotherapies for NORSE as early as possible, because this condition is associated with high mortality and morbidity owing to prolonged seizure activity and long-term intensive care including general anesthesia and mechanical ventilation.

Pediatric refractory and super-refractory status epilepticus

PURPOSE

To summarize the available evidence related to pediatric refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE), with emphasis on epidemiology, etiologies, therapeutic approaches, and clinical outcomes.

METHODS

Narrative review of the medical literature using MEDLINE database.

RESULTS

RSE is defined as status epilepticus (SE) that fails to respond to adequately used first- and second-line antiepileptic drugs. SRSE occurs when SE persist for 24 h or more after administration of anesthesia, or recurs after its withdrawal. RSE and SRSE represent complex neurological emergencies associated with long-term neurological dysfunction and high mortality. Challenges in management arise as the underlying etiology is not always promptly recognized and therapeutic options become limited with prolonged seizures. Treatment decisions mainly rely on case series or experts' opinions. The comparative effectiveness of different treatment strategies has not been evaluated in large prospective series or randomized clinical trials. Continuous infusion of anesthetic agents is the most common treatment for RSE and SRSE, although many questions on optimal dosing and rate of administration remain unanswered. The use of non-pharmacological therapies is documented in case series or reports with low level of evidence. In addition to neurological complications resulting from prolonged seizures, children with RSE/SRSE often develop systemic complications associated with polypharmacy and prolonged hospital stay.

CONCLUSION

RSE and SRSE are neurological emergencies with limited therapeutic options. Multi-national collaborative efforts are desirable to evaluate the safety and efficacy of current RSE/SRSE therapies, and potentially impact patients' outcomes.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.