Predictors of outcome in super refractory status epilepticus

Time to FIRE NORSE: A single acronym for a heterogeneous presentation. Further information from a case series and discussion of the literature

PURPOSE

New-Onset Refractory Status Epilepticus (NORSE) is a rare and severe form of refractory status epilepticus without an apparent underlying cause at presentation or prior history of epilepsy. We aimed to describe the clinical features, etiology, treatment, and outcomes of NORSE in adults in a quaternary-level hospital in Saudi Arabia.

METHODOLOGY

In this retrospective cohort study, inclusion criteria involved patients over 14 years old who met the 2018 consensus definition for NORSE. Patients were identified using a combination of medical record admission labels 'status epilepticus' and 'encephalitis', and continuous EEG reports documenting status epilepticus. Demographic, clinical, and radiological data were collected and then analyzed for factors correlated with specific etiologies, better functional outcomes, and future diagnosis of epilepsy.

RESULTS

We found 24 patients presenting with NORSE between 2010 and 2021. Fever/infectious symptoms were the most common prodrome. Elevated inflammatory serum and cerebrospinal fluid markers in most patients. Brain MRI revealed T2/FLAIR hyperintensity patterns, predominantly affecting limbic and perisylvian structures. The etiology of NORSE varied, with immune-related causes being the most common. Long-term outcomes were poor, with a high mortality rate and most survivors developing drug-resistant epilepsy.

CONCLUSION

This study provides valuable insights into NORSE's clinical characteristics, highlighting the heterogeneity of this condition. The poor outcome is likely related to the progressive nature of the underlying disease, where refractory seizures are a clinical symptom. Thus, we propose to focus future research on the etiology rather than the NORSE acronym.

Electroencephalography as a Biomarker of Prognosis in Acute Brain Injury

Electroencephalography (EEG) is a noninvasive tool that allows the monitoring of cerebral brain function in critically ill patients, aiding with diagnosis, management, and prognostication. Specific EEG features have shown utility in the prediction of outcomes in critically ill patients with status epilepticus, acute brain injury (ischemic stroke, intracranial hemorrhage, subarachnoid hemorrhage, and traumatic brain injury), anoxic brain injury, and toxic-metabolic encephalopathy. Studies have also found an association between particular EEG patterns and long-term functional and cognitive outcomes as well as prediction of recovery of consciousness following acute brain injury. This review summarizes these findings and demonstrates the value of utilizing EEG findings in the determination of prognosis.

Outcomes and Treatment Approaches for Super-Refractory Status Epilepticus: A Systematic Review and Meta-Analysis

Importance

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues or recurs 24 hours or more after the onset of anesthetic therapy or recurs on the reduction/withdrawal of anesthesia. Current clinical knowledge of the disease and optimal treatment approach is sparse.

Objective

To systematically assess clinical characteristics, causes, outcomes, prognostic factors, and treatment approaches for patients with SRSE.

Design, Setting, and Participants

In this systematic review and meta-analysis, all studies reporting adult patients (18 years or older) diagnosed with nonanoxic SRSE were considered for inclusion, irrespective of study design. The databases used were MEDLINE, Cochrane Library, EMBASE, and ClinicalTrials.org (database inception through May 5, 2022).

Data extraction and synthesis

The study complied with the PRISMA guidelines for reporting, data extraction, and data synthesis. Different tools were used to assess risk of bias. All available data were extracted and missing data were neither imputed nor completed by contacting the study authors.

Main outcome and measures

Successful treatment of SRSE, in-hospital mortality, and disability at discharge (estimated modified Rankin Scale).

Results

The study team identified a total of 95 articles and 30 conference abstracts reporting 1200 patients with nonanoxic SRSE (266 individual patients were available for meta-analysis). They had a mean SRSE duration of 36.3 days, mean age of 40.8 years, and equal sex distribution. Patients with SRSE had a distinct pattern of etiologies where acute cerebral events and unknown etiologies accounted for 41.6% and 22.3% of all etiologies, respectively. Reports of SRSE caused by, eg, alcohol, drugs, or tumors were rare. At discharge, only 26.8% had none to slight disability (none, 16 [8.4%]; nonsignificant and slight disability, 35 [18.4%]). In-hospital mortality was 24.1%. Mortality stabilized after long-term treatment (more than 28 days) but with increased rates of seizure cessation and moderate to severe disability. Established prognostic factors, such as age and etiology, were not associated with in-hospital mortality. Reported treatment with ketamine, phenobarbital, other barbiturates, vagus nerve stimulator, and ketogenic diet were not associated with outcome.

Conclusion and Relevance

Patients with SRSE are distinct due to their pattern of care (eg, long-term treatment to younger patients without negative prognostic factors and unknown/nonmalignant etiologies) and their natural course of SE. Very long-term treatment was associated with lower mortality and high odds of cessation of SRSE but increased risk of moderate to severe disability.