Plasmapheresis for refractory status epilepticus Part II: A scoping systematic review of the pediatric literature

Neuromodulation Techniques in Children with Super-Refractory Status Epilepticus

Status epilepticus (SE) is a life-threatening condition and medical emergency which can have lifelong consequences, including neuronal death and alteration of neuronal networks, resulting in long-term neurologic and cognitive deficits in children. When standard pharmacological treatment for SE is not successful in controlling seizures, the condition evolves to refractory SE (rSE) and finally to super-refractory SE (srSE) if it exceeds 24 h despite using anaesthetics. In this systematic review, we present literature data on the potential uses of clinical neuromodulation techniques for the management of srSE in children, including electroconvulsive therapy, vagus nerve stimulation, and deep brain stimulation. The evaluation of these techniques is limited by the small number of published paediatric cases (n = 25, one with two techniques) in peer-reviewed articles (n = 18). Although neuromodulation strategies have not been tested through randomised, prospective controlled clinical trials, this review presents the existing data and the potential benefits of neuromodulation therapy, suggesting that these techniques, when available, could be considered at earlier stages within the course of srSE intending to prevent long-term neurologic complications. Clinical trials aiming to establish whether early intervention can prevent long-term sequelae are necessary in order to establish the potential clinical value of neuromodulation techniques for the treatment of srSE in children.

Management and prognosis of pediatric status epilepticus

Background

Pediatric status epilepticus is a neurological emergency with the potential for severe developmental and neurological consequences. Prompt diagnosis and management are necessary.

Objectives

To outline the existing best available evidence for managing pediatric and neonatal status epilepticus, in the light of emerging randomized controlled studies. We also focus on short and long-term prognoses.

Materials and methods

This is a systematic overview of the existing literature.

Results

Status epilepticus, its treatment, and prognosis are usually based on the continuation of seizure activity at 5 and 30 min. Refractory and super-refractory status epilepticus further complicates management and requires continuous EEG monitoring with regular reassessment and adjustment of therapy. Benzodiazepines have been accepted as the first line of treatment on the basis of reasonable evidence. Emerging randomized controlled trials demonstrate equal efficacy for parenterally administered phenytoin, levetiracetam, and valproic acid as second-line agents. Beyond this, the evidence for third-line options is sparse. However, encouraging evidence for midazolam and ketamine exists with further data required for immunological, dietary, and surgical interventions.

Conclusion

Our overview of the management of pediatric and neonatal status epilepticus based on available evidence emphasizes the need for evidence-based guidelines to manage status epilepticus that fails to respond to second-line treatment.

Therapeutic plasma exchange in clinical pediatric neurology practice: Experience from a tertiary referral hospital

OBJECTIVE

This study aims to retrospectively evaluate the long-term efficacy, tolerability, and safety of therapeutic plasma exchange (TPE) in children with various neuroimmunological disorders.

METHODS

This analysis was a single-center, retrospective cohort study of pediatric patients with neuroimmunological events undergoing TPE procedures in a tertiary referral center.

RESULTS

There were 23 patients, 14 boys (60.9%), aged at diagnosis onset 8 months to 16.8 years. The main indications of TPE were Guillain-Barré syndrome (GBS, n = 8), autoimmune encephalitis (n = 5), febrile infection-related epilepsy syndrome (FIRES, n = 4), and acute disseminated encephalomyelitis (ADEM, n = 3). There was no life-threatening complication due to the TPE procedures. Eight (34.8%) of 23 patients experienced 13 (7%) complications in 186 TPE procedures, mostly electrolyte disturbances (n = 5). None of patients discontinued TPE due to complications. Two (8.7%) of 23 patients had marked improvement, 6 (26.1%) had moderate and 11 (47.8%) had mild improvement after TPE. The last follow-up visit revealed neurological sequelae in 12 (52.2%) patients. Therapeutic plasma exchange was found to be more effective on GBS, autoimmune encephalitis and myasthenia gravis, less effective on ADEM and FIRES. There was no correlation between improvement with TPE and clinical parameters, including age, sex, diagnosis, disease duration before TPE, presence of intubation, and length of stay in the intensive care unit and hospital.

CONCLUSION

Therapeutic plasma exchange was found to be effective and well-tolerated in children with various types of neuroimmunological disorder, with at least mild improvement in approximately 80% of the patients and no life-threatening complications.

Therapeutic Options for Patients with Refractory Status Epilepticus in Palliative Settings or with a Limitation of Life-Sustaining Therapies: A Systematic Review

BACKGROUND

Refractory status epilepticus (RSE) represents a serious medical condition requiring early and targeted therapy. Given the increasing number of elderly or multimorbid patients with a limitation of life-sustaining therapy (LOT) or within a palliative care setting (PCS), guidelines-oriented therapy escalation options for RSE have to be omitted frequently.

OBJECTIVES

This systematic review sought to summarize the evidence for fourth-line antiseizure drugs (ASDs) and other minimally or non-invasive therapeutic options beyond guideline recommendations in patients with RSE to elaborate on possible treatment options for patients undergoing LOT or in a PCS.

METHODS

A systematic review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focusing on fourth-line ASDs or other minimally or non-invasive therapeutic options was performed in February and June 2020 using the MEDLINE, EMBASE and Cochrane databases. The search terminology was constructed using the name of the specific ASD or therapy option and the term 'status epilepticus' with the use of Boolean operators, e.g. "(brivaracetam) AND (status epilepticus)". The respective Medical Subject Headings (MeSH) and Emtree terms were used, if available.

RESULTS

There is currently no level 1, grade A evidence for the use of ASDs in RSE. The best evidence was found for the use of lacosamide and topiramate (level 3, grade C), followed by brivaracetam, perampanel (each level 4, grade D) and stiripentol, oxcarbazepine and zonisamide (each level 5, grade D). Regarding non-medicinal options, there is little evidence for the use of the ketogenic diet (level 4, grade D) and magnesium sulfate (level 5, grade D) in RSE. The broad use of immunomodulatory or immunosuppressive treatment options in the absence of a presumed autoimmune etiology cannot be recommended; however, if an autoimmune etiology is assumed, steroid pulse, intravenous immunoglobulins and plasma exchange/plasmapheresis should be considered (level 4, grade D). Even if several studies suggested that the use of neurosteroids (level 5, grade D) is beneficial in RSE, the current data situation indicates that there is formal evidence against it.

CONCLUSIONS

RSE in patients undergoing LOT or in a PCS represents a challenge for modern clinicians and epileptologists. The evidence for the use of ASDs in RSE beyond that in current guidelines is low, but several effective and well-tolerated options are available that should be considered in this patient population. More so than in any other population, advance care planning, advance directives, and medical ethical aspects have to be considered carefully before and during therapy.

Pharmacotherapy for Pediatric Convulsive Status Epilepticus

Convulsive status epilepticus (CSE) is one of the most common pediatric neurological emergencies. Ongoing seizure activity is a dynamic process and may be associated with progressive impairment of gamma-aminobutyric acid (GABA)-mediated inhibition due to rapid internalization of GABA_A receptors. Further hyperexcitability may be caused by AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and NMDA (N-methyl-D-aspartic acid) receptors moving from subsynaptic sites to the synaptic membrane. Receptor trafficking during prolonged seizures may contribute to difficulties treating seizures of longer duration and may provide some of the pathophysiological underpinnings of established and refractory SE (RSE). Simultaneously, a practice change toward more rapid initiation of first-line benzodiazepine (BZD) treatment and faster escalation to second-line non-BZD treatment for established SE is in progress. Early administration of the recommended BZD dose is suggested. For second-line treatment, non-BZD anti-seizure medications (ASMs) include valproate, fosphenytoin, or levetiracetam, among others, and at this point there is no clear evidence that any one of these options is better than the others. If seizures continue after second-line ASMs, RSE is manifested. RSE treatment consists of bolus doses and titration of continuous infusions under continuous electro-encephalography (EEG) guidance until electrographic seizure cessation or burst-suppression. Ultimately, etiological workup and related treatment of CSE, including broad spectrum immunotherapies as clinically indicated, is crucial. A potential therapeutic approach for future studies may entail consideration of interventions that may accelerate diagnosis and treatment of SE, as well as rational and early polytherapy based on synergism between ASMs by utilizing medications targeting different mechanisms of epileptogenesis and epileptogenicity.

Therapeutic apheresis in neurological, nephrological and gastrointestinal diseases

Therapeutic plasma exchange (TPE) is a process in which plasma containing antibodies, immune complexes, inflammatory moderators, paraproteins and other toxins which are believed to be the cause of disease is removed from a patient. TPE is the first-line treatment (category I, level 1A) in all forms of Acute inflammatory demyelinating polyradiculoneuropathy disease (axonal, demyelinating and miller-fisher variant) as well as in acute myasthenic crisis, chronic inflammatory demyelinating polyradiculoneuropathy and Paraproteinemic neuropathies (category I, level 1B). Moreover, TPE in kidney diseases, for instance: desensitization in renal transplantation(ABO compatible) (living donor)and desensitization in deceased donor, desensitization in renal transplantation(ABO incompatible) (living donor), thrombotic microangiopathy complement Mediated (Factor H autoantibodies), Focal segmental glomerulosclerosis(recurrent in transplanted kidney), ANCA-associated rapidly progressive glomerulonephritis(Dialysis dependence, DAH), Anti-Glomerular basement membrane disease Goodpasture's syndrome)(DAH,Dialysis-independence,) has been utilized as an initial treatment. (category I) TPE has been used as the key therapeutic modality to reduce anti-A or anti-B antibody titers in the liver peri-transplant period with the goal of preventing rejection and facilitating graft survival. Also, plasma exchange is the first-line therapy in Wilson's disease (category I, level1C).

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.

Plasma Exchange as a Therapeutic Modality in a Rare Case of Cryptogenic New Onset Refractory Status Epilepticus (NORSE)

Refractory Status Epilepticus (RSE) not responding to any therapy and not associated with any aetiology has been termed as New Onset Refractory Status Epilepticus (NORSE). Guidelines for optimal management of cryptogenic NORSE are not clearly defined so far in the literature. Other than common medication, use of high-dose steroids, IV immune globulins and plasma exchanges in NORSE of unknown aetiology have been scarcely described. Immunomodulatory therapy like plasmapheresis is based on the fact that a pathological substance exists in the plasma that contributes to the disease process and its symptoms, which gets removed. We report a case of young female patient diagnosed as NORSE who responded to treatment with plasma exchange after becoming refractory to antiepileptic therapy and treatment with anaesthetic agents for recurrent seizers.