Status epilepticus: what's new for the intensivist.

PURPOSE OF REVIEW: Status epilepticus (SE) is a common neurologic emergency affecting about 36.1/100 000 person-years that frequently requires intensive care unit (ICU) admission. There have been advances in our understanding of epidemiology, pathophysiology, and EEG monitoring of SE, and there have been large-scale treatment trials, discussed in this review. RECENT FINDINGS: Recent changes in the definitions of SE have helped guide management protocols and we have much better predictors of outcome. Observational studies have confirmed the efficacy of benzodiazepines and large treatment trials indicate that all routinely used second line treatments (i.e., levetiracetam, valproate and fosphenytoin) are equally effective. Better understanding of the pathophysiology has indicated that nonanti-seizure medications aimed at underlying pathological processes should perhaps be considered in the treatment of SE; already immunosuppressant treatments are being more widely used in particular for new onset refractory status epilepticus (NORSE) and Febrile infection-related epilepsy syndrome (FIRES) that sometimes revealed autoimmune or paraneoplastic encephalitis. Growing evidence for ICU EEG monitoring and major advances in automated analysis of the EEG could help intensivist to assess the control of electrographic seizures. SUMMARY: Research into the morbi-mortality of SE has highlighted the potential devastating effects of this condition, emphasizing the need for rapid and aggressive treatment, with particular attention to cardiorespiratory and neurological complications. Although we now have a good evidence-base for the initial status epilepticus management, the best treatments for the later stages are still unclear and clinical trials of potentially disease-modifying therapies are long overdue.

The etiology and mortality of new-onset refractory status epilepticus (NORSE) in adults: A systematic review and meta-analysis.

New-onset refractory status epilepticus (NORSE) is a devastating neurological presentation. There is a paucity of large studies on NORSE as it is a relatively new clinical syndrome. The aim of this review was to summarize the etiologies and establish a mortality rate for NORSE. Two independent authors systematically searched the following electronic databases from January 1, 2005 April 20, 2021: PubMed, Embase, OVID, Scopus, Web of Science, "Clinicaltrials.gov," and the International Standard Randomised Controlled Trial Number (ISRCTN) registry. We included all primary research studies of NORSE in adults and excluded commentaries, reviews, pre-clinical studies, and pediatric populations. Etiology was extracted from all studies meeting eligibility criteria, whereas data relating to treatments, hospital stay, functional outcomes, and mortality were extracted from studies with sample size ≥5. We conducted a random-effects meta-analysis of mortality rate with meta-regression testing for significant covariates. Of 1482 studies, 109 case reports and case series met our criteria, comprising 395 cases of NORSE. The most common etiology was cryptogenic in 197 cases (49.9%), followed by autoimmune in 143 cases (36.2%). The pooled mortality rate was 22% (95% confidence interval 17%-27%; N studies  = 15), with low heterogeneity ( I 2  = 0%). Meta-regression revealed that year of study, treatment with ketogenic diet or immunotherapy, percentage of cryptogenic cases, and length of intensive care unit stay were not significant covariates for mortality. Common treatments included antiseizure medications (median 5), general anesthesia, and immunotherapy such as corticosteroids, intravenous immunoglobulin, and plasma exchange. Mean length of intensive care admission was 33.4 days, with 52% of cases diagnosed with epilepsy on discharge. Neurocognitive impairment was a common sequela of NORSE. NORSE is associated with a high mortality. Half of cases remain cryptogenic, which presents a diagnostic challenge. Future focus should be on elucidating the underlying neurobiology and determining the most effective therapeutic interventions.

Prognosis of adults and children following a first unprovoked seizure.

BACKGROUND: Epilepsy is clinically defined as two or more unprovoked epileptic seizures more than 24 hours apart. Given that, a diagnosis of epilepsy can be associated with significant morbidity and mortality, it is imperative that clinicians (and people with seizures and their relatives) have access to accurate and reliable prognostic estimates, to guide clinical practice on the risks of developing further unprovoked seizures (and by definition, a diagnosis of epilepsy) following single unprovoked epileptic seizure. OBJECTIVES: 1. To provide an accurate estimate of the proportion of individuals going on to have further unprovoked seizures at subsequent time points following a single unprovoked epileptic seizure (or cluster of epileptic seizures within a 24-hour period, or a first episode of status epilepticus), of any seizure type (overall prognosis). 2. To evaluate the mortality rate following a first unprovoked epileptic seizure. SEARCH METHODS: We searched the following databases on 19 September 2019 and again on 30 March 2021, with no language restrictions. The Cochrane Register of Studies (CRS Web), MEDLINE Ovid (1946 to March 29, 2021), SCOPUS (1823 onwards), ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). CRS Web includes randomized or quasi-randomized, controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups including Epilepsy. In MEDLINE (Ovid) the coverage end date always lags a few days behind the search date. SELECTION CRITERIA: We included studies, both retrospective and prospective, of all age groups (except those in the neonatal period (< 1 month of age)), of people with a single unprovoked seizure, followed up for a minimum of six months, with no upper limit of follow-up, with the study end point being seizure recurrence, death, or loss to follow-up. To be included, studies must have included at least 30 participants. We excluded studies that involved people with seizures that occur as a result of an acute precipitant or provoking factor, or in close temporal proximity to an acute neurological insult, since these are not considered epileptic in aetiology (acute symptomatic seizures). We also excluded people with situational seizures, such as febrile convulsions. DATA COLLECTION AND ANALYSIS: Two review authors conducted the initial screening of titles and abstracts identified through the electronic searches, and removed non-relevant articles. We obtained the full-text articles of all remaining potentially relevant studies, or those whose relevance could not be determined from the abstract alone and two authors independently assessed for eligibility. All disagreements were resolved through discussion with no need to defer to a third review author. We extracted data from included studies using a data extraction form based on the checklist for critical appraisal and data extraction for systematicreviews of prediction modelling studies (CHARMS). Two review authors then appraised the included studies, using a standardised approach based on the quality in prognostic studies (QUIPS) tool, which was adapted for overall prognosis (seizure recurrence). We conducted a meta-analysis using Review Manager 2014, with a random-effects generic inverse variance meta-analysis model, which accounted for any between-study heterogeneity in the prognostic effect. We then summarised the meta-analysis by the pooled estimate (the average prognostic factor effect), its 95% confidence interval (CI), the estimates of I² and Tau² (heterogeneity), and a 95% prediction interval for the prognostic effect in a single population at three various time points, 6 months, 12 months and 24 months. Subgroup analysis was performed according to the ages of the cohorts included; studies involving all ages, studies that recruited adult only and those that were purely paediatric. MAIN RESULTS: Fifty-eight studies (involving 54 cohorts), with a total of 12,160 participants (median 147, range 31 to 1443), met the inclusion criteria for the review. Of the 58 studies, 26 studies were paediatric studies, 16 were adult and the remaining 16 studies were a combination of paediatric and adult populations. Most included studies had a cohort study design with two case-control studies and one nested case-control study. Thirty-two studies (29 cohorts) reported a prospective longitudinal design whilst 15 studies had a retrospective design whilst the remaining studies were randomised controlled trials. Nine of the studies included presented mortality data following a first unprovoked seizure. For a mortality study to be included, a proportional mortality ratio (PMR) or a standardised mortality ratio (SMR) had to be given at a specific time point following a first unprovoked seizure. To be included in the meta-analysis a study had to present clear seizure recurrence data at 6 months, 12 months or 24 months. Forty-six studies were included in the meta-analysis, of which 23 were paediatric, 13 were adult, and 10 were a combination of paediatric and adult populations. A meta-analysis was performed at three time points; six months, one year and two years for all ages combined, paediatric and adult studies, respectively. We found an estimated overall seizure recurrence of all included studies at six months of 27% (95% CI 24% to 31%), 36% (95% CI 33% to 40%) at one year and 43% (95% CI 37% to 44%) at two years, with slightly lower estimates for adult subgroup analysis and slightly higher estimates for paediatric subgroup analysis. It was not possible to provide a summary estimate of the risk of seizure recurrence beyond these time points as most of the included studies were of short follow-up and too few studies presented recurrence rates at a single time point beyond two years. The evidence presented was found to be of moderate certainty. AUTHORS' CONCLUSIONS: Despite the limitations of the data (moderate-certainty of evidence), mainly relating to clinical and methodological heterogeneity we have provided summary estimates for the likely risk of seizure recurrence at six months, one year and two years for both children and adults. This provides information that is likely to be useful for the clinician counselling patients (or their parents) on the probable risk of further seizures in the short-term whilst acknowledging the paucity of long-term recurrence data, particularly beyond 10 years.

Cryptococcal meningoencephalitis in multiple sclerosis treated with fingolimod.

A 21-year-old woman with multiple sclerosis (taking regular fingolimod) developed sudden-onset severe headache with nausea and malaise. Neurological examination was normal and she was afebrile. Blood results showed lymphocytes 0.53 x 109/L and C reactive protein 19 mg/L. CT scan of head and venogram were normal. CSF showed an opening pressure of 33 cm H2O and an incidental light growth of Cryptococcus neoformans, confirmed with positive India Ink stain and a positive cryptococcal antigen (1:100). She was treated for cryptococcal meningoencephalitis with amphotericin and flucytosine. Her presenting symptoms had closely mimicked subarachnoid haemorrhage. This atypical presentation of cryptococcal CNS infection highlights the need for vigilance in immunosuppressed patients.

Advances in the management of generalized convulsive status epilepticus: what have we learned?

Convulsive status epilepticus is the most serious manifestation of an epileptic diathesis. In the early stages (5-30 min), there exists class A evidence to support the efficacy of benzodiazepines as first-line treatment. As status epilepticus progresses into the later stages, the evidence for treatment becomes less robust until we are depending upon short case series and case reports for the treatment of refractory status epilepticus. However, the past year saw the publication of three randomized controlled trials in the setting of benzodiazepine-resistant established convulsive status epilepticus: the EcLiPSE and ConSEPT studies, compared levetiracetam to phenytoin in children; and the ESETT study compared fosphenytoin, levetiracetam and sodium valproate in adults and children. In addition, the emergence of data from the SENSE study, a multicentre multinational prospective cohort study and the publication of a systematic review and meta-analysis of the mortality of status epilepticus over the past 30 years, has brought the treatment of status epilepticus into sharp focus. In this update we provide a detailed analysis of these studies and their impact on clinical practice. We review contentious areas of management in status epilepticus where a consensus is lacking and advance the case for more research on existing and alternative treatment strategies.

New-Onset Refractory Status Epilepticus (NORSE): The Queen Square Neuro-ICU experience.

The introduction and widespread adoption of the term 'NORSE' - new-onset refractory status epilepticus - raises both fundamental conceptual and pragmatic questions. We studied a cohort of patients with 'NORSE' at the National Hospital for Neurology and Neurosurgery to investigate the clinical features, treatment responses, and outcomes with a focus on sub-group analysis. We identified 26 cases of 'NORSE'. There was no difference in prognosis between 'NORSE' and non-'NORSE' RSE, nor in any sub-analysis in the 'NORSE' cohort. We discuss the utility and validity of the term NORSE as a descriptor for a subgroup with RSE in whom the underlying etiologies are heterogeneous and pathophysiological mechanisms are unknown.

First evidence of the clinical impact of a general practitioner with a special interest in epilepsy.

PURPOSE: The purpose of the study was to review the clinical outcomes of people with epilepsy (PWE) attending a primary care-based specialist epilepsy service. METHOD: The case notes of 355 people attending the service and subsequent follow-up from 2005 to 2013 were reviewed. RESULTS: There had been 37 deaths (all nonattributable to epilepsy), and 38 people had left the area, leaving 280 people who completed the audit. Positive outcomes could be attributed in 94% still attending the service at the end of follow-up. Seventy-five percent of people on treatment, referred with poor seizure control, achieved seizure remission with antiepilepsy drug (AED) changes initiated by the service. CONCLUSION: This study suggests that the majority of people who attended the service had a positive outcome and provides the first evidence for the clinical effectiveness of a general practitioner (GP) with special interest in epilepsy (GPwSIe) and provides support for the recommendations in earlier government reports to promote the use of such a service. Clinical Commissioning Groups (CCGs) and Government should consider investment in this intermediate tier of care as a means to both improving the quality of care and potentially reducing costs.

Epilepsy mortality trends in Cuba compared with England and Wales: 1987-2010.

There are limited epilepsy mortality data from developing countries and Latin America in particular. We examined national epilepsy mortality data from Cuba and contrasted them with comparable data from England and Wales. National epilepsy mortality data for Cuba between the years 1987 and 2010 were obtained from the Medical Records and Health Statistics Bureau of the Cuban Public Health Ministry (www.sld.cu/sitios/dne/) with the corresponding mortality data from England and Wales obtained from the UK Office of National Statistics (ONS, www.ons.gov.uk). Indirect standardization with calculation of a standardized mortality ratio (SMR) was used to compare trends. The overall trend was of a slight decrease in mortality rates over the 23 years in Cuba, with higher mortality rates primarily occurring in young people. Annual age-adjusted rates were consistently lower in Cuba than those seen in England and Wales, with the SMR ranging from 0.35 (95% confidence interval (CI): 0.30 to 0.48) in 2007 to 1.00 (95% CI: 0.85 to 1.15) in 1994. Cuban epilepsy mortality rates are consistently lower than those of England and Wales. Reasons for this disparity in mortality rates are not immediately apparent but are likely to be multifactorial.

Outcome of seizures in the general population after 25†years: a prospective follow-up, observational cohort study.

OBJECTIVES: We investigated long-term (to 25 years) seizure prognosis and survival in people with newly diagnosed epilepsy in the community. We explored whether prognosis is different in those with epilepsy (>2 unprovoked seizures) and those with a single seizure at presentation. METHODS: This is a prospective observational cohort study of people with newly diagnosed seizures. We investigated seizure outcome and survival in people presenting with a single seizure and in those presenting with >2 seizures (epilepsy). RESULTS: 695 people (median follow-up 23.6 years) had unprovoked epileptic seizures. For seizure analysis we excluded 38 people with missing data leaving 657 (309 male, and 249 aged <18 years). Seizures recurred in 67%. The 354 people with epilepsy were only slightly more likely to have further seizure recurrence than the 302 people with a single seizure at presentation (HR 1.32, 95% CI 1.09 to 1.59). In 327 people with complete follow-up, 268 (82%, 95% CI 77% to 86%) were in terminal remission; (80%, (95% CI 73% to 85%) in those with epilepsy at presentation). Premature mortality was increased in people with epilepsy (standardised mortality ratio 1.67; 95% CI 1.40 to 1.99) and those with a single seizure at presentation (standardised mortality ratio 2.65; 95% CI 2.23 to 3.15). It is also high in those with early remission. CONCLUSIONS: People with epilepsy and with single seizures at presentation in the community generally have good prognosis for seizure control with prolonged follow-up. The risk of premature mortality is significantly increased in both groups.

Falling status epilepticus mortality rates in England and Wales: 2001-2013?

Status epilepticus (SE) is associated with significant mortality and accounts for ~10% of epilepsy-related deaths. Epilepsy and SE mortality data from 2001 to 2013, in addition to annual age group populations for England and Wales, were obtained from the Office of National Statistics website (www.ons.gov.uk). Age-adjusted mortality rates for epilepsy and SE with 95% confidence intervals (CIs) were calculated using the European Standard Population. Trends in mortality rates for both epilepsy and SE were investigated using the Spearman coefficient. The crude mean epilepsy mortality rate per 100,000 person-years between 2001 and 2013 was 1.87 (95% CI 1.83-1.91), with a corresponding SE mortality rate of 0.14 (95% CI 0.13-0.15). The mean age-adjusted epilepsy mortality rate per 100,000 person years was 3.24 (95% CI 3.12-3.35), with a corresponding SE mortality rate of 0.24 (95% CI 0.21-0.27). All epilepsy deaths significantly decreased from 2001 to 2013 (Spearman's ρ -0.733, p = 0.004); this decrease was predominantly due to a decrease in SE deaths (Spearman's ρ -0.917, p < 0.001). In summary, our finding supports the hypothesis that the policy of early and aggressive treatment of SE may be improving the prognosis of this condition in England and Wales.

An unknown quantity--the worldwide prevalence of epilepsy.

The reported incidence (rate of new cases in a population) of epilepsy is consistently lower in high-income than in lower-income economies, whereas opinions vary regarding comparative prevalence rates (proportion of the population with epilepsy). For any condition that does not influence mortality, lifetime prevalence should approximate to the cumulative incidence. We suspected that epilepsy prevalence might be uniform throughout the world, whereas incidence is higher in resource-poor countries. To test whether our suspicion was reasonable, we conducted a Medline search to estimate the prevalence of active and lifetime epilepsy in different economic areas throughout the world. We found that the range of estimated prevalence of epilepsy may be broadly similar throughout the world, but comparison is limited by lack of door-to-door studies in high-income economies and by variations in the definitions of active epilepsy. We contend that any inconsistencies between incidence and prevalence are due largely to the excess premature death rate in people with epilepsy in lower-income economies. Much of the variability in epidemiologic indices arises from differences in study methodology, definitions, and risk factors. The epidemiology of epilepsy, and particularly its mortality, needs thorough investigation using uniform definitions that do not include antiepileptic drug use; causes of death should be identified and actions, including treatment and education, should be taken to avoid preventable deaths.

A survey of adult and pediatric epilepsy surgery in the United Kingdom.

All consultant epilepsy neurosurgeons were asked to prospectively record all epilepsy surgery procedures carried out at their center between April 2010 and March 2011. Figures were compared to a previous survey completed in 2000. Of a total of 710 procedures, temporal lobe surgery was the most common resective surgery. Although extratemporal lesional surgery was less common, vagus nerve stimulator (VNS) implantation accounted for almost half the procedures. The numbers for all surgical procedures, with the exception of VNS implantations, had decreased. This decrease may represent a global rather than a regional phenomenon. Further longitudinal multinational data on epilepsy surgery is required to confirm or refute this theory.

Early and established status epilepticus: The impact of timing of intervention, treatment escalation and dosing on outcome.

OBJECTIVE: We investigated the management and outcome of early and established status epilepticus including timing, dosing and selection of benzodiazepines along with the timing and efficacy of second line treatments. METHODS: Retrospective single tertiary centre observational cohort study to identify all cases of SE between January 2019 and February 2022. RESULTS: 252 cases were identified. Seizures terminated spontaneously in 136 (54%) cases. 116 (46%) were given benzodiazepines, of which 29 (25%) were given at least one benzodiazepine by family/carers, and 72 (62.1%) received benzodiazepines by ambulance services. Benzodiazepines terminated seizures in 83 (71.6%) cases. The commonest benzodiazepine used was buccal midazolam (35.5%). Median time to first benzodiazepine was 14.5 (6-27) minutes. There was a positive correlation between time to first benzodiazepine and time to seizure cessation, progression to second- and third-line treatment, and respiratory complications (p<0.05). 73 (62.9%) cases received a correct benzodiazepine dose. Benzodiazepine underdosing was associated with longer seizure duration (p<0.05). 33 (28.4%) cases progressed to second-line treatment where mean time to treatment was 59.4 min (±32.3 min). The commonest second-line treatment was Levetiracetam (53.8%), followed by Phenytoin (43.6%) with SE termination in 57.5% cases. 14 (12.1%) cases progressed to third-line treatment; mean time to treatment was 60.6 min (±22.24 min). Respiratory complications occurred in 17 (6.75%) cases; none due to benzodiazepines. There were two deaths in refractory SE. CONCLUSION: Early administration of benzodiazepines and optimal dosing is associated with a higher rate of SE termination. Levetiracetam was the most commonly used second line treatment.

What are the chances of having a second epileptic seizure?

The studyNeligan A, Adan G, Nevitt SJ, et al. Prognosis of adults and children following a first unprovoked seizure. Cochrane Database Syst Rev 2023;1:1-75.To read the full NIHR Alert, go to: https://evidence.nihr.ac.uk/alert/epilepsy-what-are-the-chances-of-having-a-second-seizure/.

Treatment changes in a cohort of people with apparently drug-resistant epilepsy: an extended follow-up.

BACKGROUND: The seizure response to the addition of a previously unused antiepileptic drug in a cohort of 155 people with refractory epilepsy was previously reported after a median of 18 months follow-up. METHODS: The authors followed 139 (90%) of the original cohort for a median follow-up of 6.9 years to determine the longer term outcome in people with refractory epilepsy. RESULTS: During the 6.9 year follow-up period, a total of 448 medication changes were made. Eight per cent of these resulted in 12 months or more of seizure freedom and a further 17% of changes resulted in at least 50% improvement in seizure frequency. At the last follow-up, 26 (19%) of individuals had been seizure-free for 12 months or more, and 41 (29%) had 50%-99% improvement in seizure frequency. Terminal seizure freedom was correlated with having no seizures at the time of the previous report (p=0.03), a lower number of previous antiepileptic drugs taken (p=0.052) and a lower number of concomitant antiepileptic drugs (p=0.03). In those who entered remission the probability of remaining seizure-free 5 years later was 0.48 (95% CI 0.32 to 0.63). DISCUSSION: This suggests that about half of people with apparent drug-resistant epilepsy can have significant improvements in seizure control with further drug changes. Some will subsequently relapse, but long periods of seizure freedom or significantly improved seizure control in the absence of complete seizure control can occur. Such valuable improvements suggest that the recently proposed International League against Epilepsy definition of refractory epilepsy may be too restrictive.

The long-term risk of premature mortality in people with epilepsy.

People with epilepsy have an increased risk of premature death. The risk is highest soon after onset of seizures. We report the findings of a long-term follow-up population-based study of people with epilepsy with regards to premature mortality. The National General Practice Study of Epilepsy is a prospective study flagged at the National Health Service Information Centre in the UK. Over 1000 people with new onset seizures were followed from the mid 1980s until April 2009. Of these, 564 people were classified at 6 months as having definite epileptic seizures, 228 as having possible epileptic seizures and 220 as having febrile seizures. The remainder were excluded (n=104 because of an unknown prior diagnosis of epilepsy or neonatal seizures) or classified as not having epilepsy (n=79). At median follow-up of 22.8 years there had been 301 deaths in the cohort; 300 of these were in people with definite or possible seizures. Death certificates were obtained for all but three of those who died. The overall standardized mortality ratio for those with definite or possible epilepsy was 2.2 (95% confidence interval 1.97-2.47), and was higher in those with definite seizures (2.6). In those who were alive at 20 years follow-up, the standardized mortality ratio in the subsequent years remained significantly elevated (2.2, 95% confidence interval 1.6-3.2). Pneumonia (standardized mortality ratio 6.6, 95% confidence incidence 5.1, 8.4) was a common cause of death with a consistently elevated standardized mortality ratio throughout follow-up. The standardized mortality ratio for ischaemic heart disease was significantly elevated for the first time in the last 5 years of follow-up (3.3, 95% confidence interval 1.6-7.0). Few people died from epilepsy-related causes. The risk of premature death remains significantly elevated at 20-25 years after the index seizure despite most of the cohort being in terminal remission (defined as 5 years or more seizure-free, on or off anti-epileptic medication) at the last follow-up. Further studies are needed to explore the reasons for this long-term increase in premature mortality.

Educational inequalities in epilepsy mortality in the Baltic countries and Finland in 2000-2015.

Little is known about socioeconomic differences in epilepsy mortality. This study examined educational inequalities in epilepsy mortality in the general population in the Baltic countries and Finland in 2000-2015. Education-specific mortality estimates for individuals aged 30-74 in Estonia, Latvia and Lithuania were obtained from census-linked mortality datasets while data for Finland came from the register-based population and death data file of Statistics Finland. Trends and educational inequalities in epilepsy mortality were assessed using age-standardised mortality rates (ASMRs) per 100,000 person years and age-adjusted mortality rate ratios (RRs) calculated using Poisson regression. ASMRs were higher in men than women in all countries. ASMRs reduced in 2000-2015 among all men and women except for Finnish women. Among men, an inverse educational gradient in epilepsy mortality in 2000-2007 widened in 2008-2015 with ASMRs falling among high and mid educated men in all countries but increasing among low educated men in three countries. An inverse educational gradient in female mortality remained in all countries throughout 2000-2015. Although epilepsy mortality fell in the Baltic countries and Finland (men only) in 2000-2015, this masked a clear inverse educational gradient in mortality that became steeper across the period.