New onset refractory status epilepticus: State of the art

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.

Drug-resistant seizures associated with hyperinflammatory monocytes in FIRES

OBJECTIVE

Therapeutic strategies for patients with febrile infection-related epilepsy syndrome (FIRES) are limited, ad hoc, and frequently ineffective. Based on evidence that inflammation drives pathogenesis in FIRES, we used ex vivo stimulation of peripheral blood mononuclear cells (PBMCs) to characterize the monocytic response profile before and after therapy in a child successfully treated with dexamethasone delivered intrathecally six times between hospital Day 23 and 40 at 0.25 mg/kg/dose.

METHODS

PBMCs were isolated from serial blood draws acquired during refractory status epilepticus (RSE) and following resolution associated with intrathecal dexamethasone therapy in a previously healthy 9-year-old male that presented with seizures following Streptococcal pharyngitis. Cells were stimulated with bacterial or viral ligands and cytokine release was measured and compared to responses in age-matched healthy control PBMCs. Levels of inflammatory factors in the blood and CSF were also measured and compared to pediatric healthy control ranges.

RESULTS

During RSE, serum levels of IL6, CXCL8, HMGB1, S100A8/A9, and CRP were significantly elevated. IL6 was elevated in CSF. Ex vivo stimulation of PBMCs collected during RSE revealed hyperinflammatory release of IL6 and CXCL8 in response to bacterial stimulation. Following intrathecal dexamethasone, RSE resolved, inflammatory levels normalized in serum and CSF, and the PBMC hyperinflammatory response renormalized.

SIGNIFICANCE

FIRES may be associated with a hyperinflammatory monocytic response to normally banal bacterial pathogens. This hyperinflammatory response may induce a profound neutrophil burden and the consequent release of factors that further exacerbate inflammation and drive neuroinflammation. Intrathecal dexamethasone may resolve RSE by resetting this inflammatory feedback loop.

New-Onset Refractory Status Epilepticus Secondary to COVID-19 Infection in Adults: A Systematic Review

BACKGROUND

New-onset refractory status epilepticus (NORSE) has been reported in the scientific literature as a phenomenon associated with the COVID-19 infection. Given the resurgence of the newer variants of COVID-19 added with its multi-system manifestations, this project was conducted to study the clinical picture of NORSE secondary to COVID-19 infection.

METHODS

Three electronic databases were searched using an extensive search strategy from November 2019 to December 2021. Patients reporting NORSE secondary to COVID-19 were included in this review. The status epilepticus severity score (STESS) was calculated by the study authors for individual patients. Statistical analysis was performed using SPSS version 26 with a p-value <0.05 as statistically significant.

RESULTS

After screening, 12 patients were included in this study with a mean age of 61.6 ± 19.0-year olds. The most common type of status epilepticus reported in our study population was non-convulsive status epilepticus (NCSE) (7 out of 12 patients, 58.3%). The linear regression model revealed that STESS scores were significantly influenced by patients' age (p = 0.004) and intra-hospital occurrence (IHO) of status epilepticus (p = 0.026). Overall, 8 patients (66.7%) were discharged without complications.

CONCLUSION

Given the observed association of STESS with the aging population and IHO of status epilepticus, special attention is due to the caretakers of this population, while further studies are needed to further build upon this review.