Long-term survival of people with unprovoked seizures: a population-based study

Psychogenic Nonepileptic Seizures-High Mortality Rate Is a 'Wake-Up Call'

Patients with epilepsy have an elevated mortality rate compared to the general population and now studies are showing a comparable death ratio in patients diagnosed with psychogenic nonepileptic seizures. The latter is a top differential diagnosis for epilepsy and the unexpected mortality rate in these patients underscores the importance of an accurate diagnosis. Experts have called for more studies to elucidate this finding but the explanation is already available, embedded in the existing data. To illustrate, a review of the diagnostic practice in epilepsy monitoring units, of the studies examining mortality in PNES and epilepsy patients, and of the general clinical literature on the two populations was conducted. The analysis reveals that the scalp EEG test result, which distinguishes a psychogenic from an epileptic seizure, is highly fallible; that the clinical profiles of the PNES and epilepsy patient populations are virtually identical; and that both are dying of natural and non-natural causes including sudden unexpected death associated with confirmed or suspected seizure activity. The recent data showing a similar mortality rate simply constitutes more confirmatory evidence that the PNES population consists largely of patients with drug-resistant scalp EEG-negative epileptic seizures. To reduce the morbidity and mortality in these patients, they must be given access to treatments for epilepsy.

Mortality, and life expectancy in Epilepsy and Status epilepticus-current trends and future aspects

Patients with epilepsy carry a risk of premature death which is on average two to three times higher than in the general population. The risk of death is not homogenously distributed over all ages, etiologies, and epilepsy syndromes. People with drug resistant seizures carry the highest risk of death compared to those who are seizure free, whose risk is similar as in the general population. Most of the increased risk is directly related to the cause of epilepsy itself. Sudden unexplained death in epilepsy patients (SUDEP) is the most important cause of epilepsy-related deaths especially in the young and middle-aged groups. Population based studies with long-term follow up demonstrated that the first years after diagnosis carry the highest risk of death, while in the later years the mortality decreases. Improved seizure control and being exposed to a specialized comprehensive care centre may help to reduce the risk of death in patients with epilepsy. The mortality of status epilepticus is substantially increased with case fatality rates between 4.6% and 39%, depending on its cause and duration, and the age of the population studied. The epidemiological data on overall and cause specific mortality as well as their determinants and risk factors are critically reviewed and methodological issues pertinent to the studies on mortality of epilepsy and Status epilepticus are discussed.

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.

Incidence and mortality in adults with epilepsy in northern Spain

OBJECTIVES

We aimed to determine the regional incidence and mortality of adult epilepsy, compare mortality rates with the expected in the general population, and identify predictors of shorter survival.

MATERIALS AND METHODS

We included all consecutive newly diagnosed epilepsy visited at a university hospital in Spain throughout 2012. We collected all relevant clinical data up to December 2018. We analyzed the incidence of epilepsy in our catchment area, studied mortality rates, and explored factors predictive of shorter survival.

RESULTS

The annual incidence of epilepsy among adults was 37.7 cases/100,000 inhabitants. We studied 110 patients with newly diagnosed epilepsy. Mean age was 52.6 years, and 53.6% were men. Eighty-nine patients (80.9%) had focal epilepsy, 50 (45.5%) had a structural etiology, and 45 (40.9%) had an unknown cause. Nineteen patients died over a median follow-up of 5.3 years. Mortality was almost four times higher than expected in general population and was increased in patients aged 40-59 years. Mortality rates were 5.5%, 12%, and 16.8% in the first, second, and third year, after which they remained stable to the end of follow-up. Independent predictors of mortality were age (p = 0.001), tumor-related epilepsy (p = 0.003), and generalized seizures (p = 0.020).

CONCLUSIONS

There is a high incidence of epilepsy among adults in our geographic area, with a mortality rate quadrupling that expected for the general population. Age, generalized seizures, and tumor-related epilepsy are independently associated with a higher risk of death.

Overall and cause-specific premature mortality in epilepsy: A systematic review

BACKGROUND

We conducted a systematic review to ascertain the overall mortality and causes of premature mortality in epilepsy.

METHODOLOGY

We searched PubMed and Embase to identify relevant articles reporting mortality in epilepsy. An assessment of the methodological quality and overall quality of evidence of the identified studies was done using appropriate checklists. We extracted data from these studies reporting measures of overall and cause-specific mortality in epilepsy.

RESULTS

Sixty-three articles from fifty-six cohorts met the eligibility criteria, thirty-three population- or community-based and twenty-three hospital- or institutional-based studies. The majority of studies are from high-income countries (HIC). These studies reported overall excess mortality for people with epilepsy, with wide variability reported for population- or community-based studies and from low- and middle-income countries (LMIC). Twenty-seven articles from twenty-three cohorts reported measures of mortality for cause-specific mortality in epilepsy. People with epilepsy from HIC and LMIC have a higher risk of dying from various causes compared with the general population. Those in LMIC, however, have a particularly high chance of dying from external causes such as drowning and suicide. We observed a decrement over time in measures of overall and cause-specific mortality in cohorts.

CONCLUSIONS

Despite the heterogeneity in reports, our findings support the suggestions that people with epilepsy have an increased risk of premature mortality from various causes. Further work is needed to elucidate the mechanisms, to determine biomarkers for predicting those at risk, and to understand the implications of counseling and preventive strategies.

An Evidence Based Approach to the First Unprovoked Seizure

The objective is to illustrate the creation and structure of a particular type of Evidence Based Care (EBC) summary that has direct clinical relevance, the Critically Appraised Topic (CAT). The process consists of a step-by-step application of the EBC principles to a common neurological problem, ie., a patient presenting with a first, unprovoked generalized seizure. This includes asking a focused clinical question about prognosis for recurrence and the role of antiepileptic drugs; searching the literature to answer the question; selecting the relevant evidence (a meta-analysis about prognosis and a randomized controlled trial about therapy); appraising the literature for its validity and usefulness; and applying the results to the clinical scenario. The result is a one-page, user friendly CAT whose title states a declarative answer to the clinical question. It also contains a description of the literature search and of the evidence, the clinical bottom lines derived from the evidence, and general comments.

The burden of premature mortality of epilepsy in high-income countries: A systematic review from the Mortality Task Force of the International League Against Epilepsy

Since previous reviews of epidemiologic studies of premature mortality among people with epilepsy were completed several years ago, a large body of new evidence about this subject has been published. We aim to update prior reviews of mortality in epilepsy and to reevaluate and quantify the risks, potential risk factors, and causes of these deaths. We systematically searched the Medline and Embase databases to identify published reports describing mortality risks in cohorts and populations of people with epilepsy. We reviewed relevant reports and applied criteria to identify those studies likely to accurately quantify these risks in representative populations. From these we extracted and summarized the reported data. All population-based studies reported an increased risk of premature mortality among people with epilepsy compared to general populations. Standard mortality ratios are especially high among people with epilepsy aged <50 years, among those whose epilepsy is categorized as structural/metabolic, those whose seizures do not fully remit under treatment, and those with convulsive seizures. Among deaths directly attributable to epilepsy or seizures, important immediate causes include sudden unexpected death in epilepsy (SUDEP), status epilepticus, unintentional injuries, and suicide. Epilepsy-associated premature mortality imposes a significant public health burden, and many of the specific causes of death are potentially preventable. These require increased attention from healthcare providers, researchers, and public health professionals.

Long-term outcome of medically treated epilepsy

PURPOSE

To review the long-term outcome of epilepsy in population-based studies.

METHOD

Analysis of population-based studies.

RESULTS

About two of three patients with new-onset epilepsy will, in the long run, enter five-year terminal remission. Chances for remission are best for those with idiopathic or cryptogenic epilepsy. It is unclear whether the seizure outcome has improved over the last several decades. Social outcome, however, may have become better because of the improved level of knowledge on and public attitudes toward people with epilepsy, and possibly fewer prejudices at home, daycare, school, military and labor market.

CONCLUSION

While we still do not have a cure for epilepsy for all patients, relief of the medical and social consequences is available for many and hope is on the horizon for people with epilepsy.

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.

Epidemiology of epilepsy and its burden in Kolkata, India

BACKGROUND

Disability-adjusted life year (DALY) is a time-based measure of disease burden incorporating both disability and mortality. Our study aimed to determine the DALY lost from epilepsy in an Indian metropolis.

METHODS

A population-based prospective study on epilepsy was conducted over 5 years (2003-8) in Kolkata, India, on randomly selected 100,802 subjects (males 53,209, females 47,593) to assess prevalence as well as to capture incident cases of epilepsy and those incident cases that died. Standard case definitions were used. The data were used to estimate years of life lost (YLL) due to premature mortality, years of life lived with disability (YLD), and DALY, utilizing the prevalence-based Global Burden of Disease (GBD) 2010 approach. Age- and gender-specific figures were computed.

RESULTS

During 2003-2004, a total of 476 subjects with active epilepsy were detected and the age-adjusted prevalence rate was 4.71 per 1000. Over 5 years, there were 197 incident cases of epilepsy of whom 26 died. The age-adjusted annual incidence rate of epilepsy was 38.3 per 100,000. The all-cause standardized mortality rate (SMR) of epilepsy was 2.4. The burden of epilepsy in the year 2007-8 revealed the overall YLL was 755 per 100,000, and the overall YLD ranged from 14.45 to 31.0 per 100,000 persons depending on the clinical severity of the epilepsy. Both YLL and YLD values were higher in males than in females. The overall DALY lost due to epilepsy in 2007-8 was found to be 846.96 (males 1183.04, females 463.81) per 100,000.

CONCLUSIONS

This is the first study in India to determine the DALY of epilepsy using GBD 2010. The results reveal a substantial burden of epilepsy in our setting. Similar such studies are needed in other parts of India in both urban and rural settings.

Long-term mortality in children and young adults with epilepsy--A population-based cohort study

PURPOSE

Epilepsy is associated with an increased mortality. This study estimates the effects of co-morbid disorders on short-term and long-term mortality and presents cause-specific mortality for children and young adults with epilepsy.

METHODS

We established a population-based cohort of 1,855,946 children born in Denmark from 1977 to 2006. Children were followed from the 29th day of life until death, emigration or 31 December 2006. Data was retrieved from Danish longitudinal civil service, health and cause of death registries. Overall, 25,244 persons were diagnosed with epilepsy and 10,647 persons died during 26.2 million person years of follow-up. Among those who died, 803 were diagnosed with epilepsy prior to death. Mortality rate ratio (MRR) was estimated by comparing the mortality rate among persons with epilepsy with the mortality rate in persons without epilepsy.

RESULTS

The mortality among children and young adults with epilepsy was almost 15 times increased compared with persons without epilepsy (MRR: 14.9 (95% CI: 13.9-16.1)). After excluding persons with adverse birth outcomes and persons with comorbid neurological disorders (other than epilepsy), the MRR was still more than four times increased (MRR: 4.20 (95% CI: 3.28-5.30)). Short- and long-term MRRs were particularly high for those diagnosed with epilepsy before 5 years of age (short-term mortality (<1 year); MRR: 41.5 (95% CI: 35.4-48.3), long term mortality (≥ 1 year); MRR: 21.6 (95% CI: 19.5-23.8)). The cumulative mortality 20 years after the first epilepsy diagnosis was 7.6% (95% CI: 6.8-8.4%) among males and 5.8% (95% CI: 5.1-6.5%) among females.

Mortality and SUDEP in epilepsy patients treated with vagus nerve stimulation

OBJECTIVE

The risk of premature death is increased in patients with intractable epilepsy. The effect of vagus nerve stimulation (VNS) on mortality remains unclear. In a previous study by Annegers et al., mortality was raised, comparable to similar intractable cohorts. Our aim was to calculate standardized mortality ratios (SMRs), identify epilepsy-related deaths, and estimate sudden unexpected death in epilepsy (SUDEP) rates in patients treated with VNS for epilepsy.

METHODS

All United Kingdom patients undergoing VNS between January 1, 1995 and December 31, 2010 at King's College Hospital, London were flagged through the national Medical Research Information Service. Analysis was performed in relation to all deaths occurring by December 31, 2010. Deceased patients were identified from the national death register, and additional information on cause and circumstances of death sought where appropriate to allow for classification of deaths.

RESULTS

The cohort consisted of 466 patients, with 2993.83 person-years of follow-up and a median observation period of 5.9 years. Twenty-nine deaths occurred, 27 with the device active. SMR was 7.1 (95% confidence interval [CI] 4.8-10.3) for the active device; 12 deaths were considered epilepsy related, including 10 definite or probable SUDEP and one fatal near SUDEP. Definite/probable and fatal near SUDEP occurred at a rate of 3.7/1,000 person-years. SMRs decreased from 10.5 (5.6-19.5) in the first 2 years after implantation to 5.9 (3.7-9.5) thereafter, although CIs overlapped. SUDEP rates did not alter over time.

SIGNIFICANCE

SMRs and SUDEP rate in this study are comparable to other cohorts with intractable epilepsy, with SUDEP an important cause of death. VNS does not appear to lower the risk of premature death overall. There was a clear trend with lower SMR after 2 years of implantation, although CIs overlapped. SUDEP rates, however, did not change.

Increased mortality persists in an adult drug-resistant epilepsy prevalence cohort

OBJECTIVE

To investigate the cumulative probability of death and the standardised mortality ratio (SMR) in an adult drug-resistant epilepsy (DRE) population.

METHODS

In two separate centres during 2003-2006, we identified a total of 433 patients with DRE defined as at least one seizure per month and failure of at least two antiepileptic drugs. These patients were subsequently followed for a total follow-up of 6 years. We examined the cumulative probability of death, using Kaplan-Meier methodology, and the SMR based on mortality data from the Social Security Death Index. Clinical predictors of death were evaluated using Cox regression analysis.

RESULTS

The cumulative probability of death was 8.7% (95% CI 6.2% to 12.1%) at 6 years. The overall SMR was 2.4 (95% CI 1.7 to 3.3). It was 3.1; 95% CI 2.0 to 4.6 in subjects with remote or progressive aetiology and 1.7; 95% CI 0.8 to 2.8 in subjects with unknown aetiology. The SMR was significantly increased in those with a known remote aetiology (2.5; 95% CI (1.4 to 3.8)). Older age at enrolment and symptomatic generalised epilepsy syndrome were significant predictors of death.

DISCUSSION

Mortality is increased in this drug-resistant population; largely driven by those with a known epilepsy aetiology. The increased mortality remains even after exclusion of those with a progressive aetiology. Previous studies of incident epilepsy cohorts revealed increased mortality that declines to near-normal levels after the first several years, but in our DRE cohort, mortality remains elevated despite a median duration of epilepsy of 25 years at study entry.

Risk factors for survival in a university hospital population of dogs with epilepsy

BACKGROUND

Although a common neurological disorder in dogs, long-term outcome of epilepsy is sparsely documented.

OBJECTIVES

To investigate risk factors for survival and duration of survival in a population of dogs with idiopathic epilepsy or epilepsy associated with a known intracranial cause.

ANIMALS

One hundred and two client owned dogs; 78 dogs with idiopathic epilepsy and 24 dogs with epilepsy associated with a known intracranial cause.

METHODS

A retrospective hospital based study with follow-up. Dogs diagnosed with epilepsy between 2002 and 2008 were enrolled in the study. Owners were interviewed by telephone using a structured questionnaire addressing epilepsy status, treatment, death/alive, and cause of death.

RESULTS

Median life span was 7.6 years, 9.2 years, and 5.8 years for all dogs, and dogs with idiopathic epilepsy or dogs with epilepsy associated with a known intracranial cause (P < .001), respectively. Survival time for dogs with idiopathic epilepsy was significantly (P = .0030) decreased for dogs euthanized because of epilepsy (median: 35 months) compared to dogs euthanized for other reasons (median: 67.5 months). Neutered male dogs with idiopathic epilepsy had a significant (P = .031) shorter survival (median: 38.5 months) after index seizure compared to intact male dogs (median: 71 months). Treatment with two antiepileptic drugs (AED's) did not negatively influence survival (P = .056).

CONCLUSION AND CLINICAL IMPORTANCE

Dogs with idiopathic epilepsy can in many cases expect a life span close to what is reported for dogs in general. In dogs where mono-therapy is not sufficient, the need for treatment with two AED's is not linked to a poor prognosis.

Premature mortality in poor health and low income adults with epilepsy

OBJECTIVE

To examine mortality and causes of death (CODs) in socioeconomically disadvantaged persons with epilepsy (PWEs) in the United States.

METHODS

We performed a retrospective open cohort analysis using Ohio Medicaid claims data between 1992 and 2008 to assess mortality and COD in 68,785 adult Medicaid beneficiaries with epilepsy. Case fatality (CF), mortality rates (MRs), standardized mortality ratios (SMRs), and years of potential life lost (YPLLs) were calculated. The SMRs were estimated to compare risk of death in PWEs with that in the general Medicaid population with and without disabilities. Proportionate mortality ratios (PMRs), YPLLs, and SMRs for specific COD were also obtained.

RESULTS

There were 12,630 deaths in PWEs. CF was 18.4%, the age-race-sex adjusted MR was 18.6/1,000 person-years (95% confidence interval [CI], 18.3-18.9). The SMR was 1.8 (95% CI, 1.8-1.9) when compared to the general Medicaid population, and was 1.4 (95% CI, 1.3-1.6) when compared to those with disabilities. The average YPLL was 16.9 years (range 1-47 years). Both epilepsy and comorbid conditions significantly contributed to premature mortality in PWEs. Cardiovascular diseases, cancer, and unintentional injuries were the most common COD and account for a large proportion of YPLLs. Deaths from epilepsy-related causes occurred in about 10% of the cases.

SIGNIFICANCE

Socioeconomically deprived PWEs, especially young adults, experience high mortality and die 17 years prematurely. The high mortality in Medicaid beneficiaries with epilepsy affirms that comorbid conditions and epilepsy play a crucial role in premature death. Management of comorbid conditions is, at a minimum, as important as epilepsy management, and therefore deserves more attention from physicians, particularly those who care for Medicaid beneficiaries with epilepsy.

Mortality risks in new-onset childhood epilepsy

OBJECTIVES

Estimate the causes and risk of death, specifically seizure related, in children followed from onset of epilepsy and to contrast the risk of seizure-related death with other common causes of death in the population.

METHODS

Mortality experiences from 4 pediatric cohorts of newly diagnosed patients were combined. Causes of death were classified as seizure related (including sudden unexpected death [SUDEP]), natural causes, nonnatural causes, and unknown.

RESULTS

Of 2239 subjects followed up for >30 000 person-years, 79 died. Ten subjects with lethal neurometabolic conditions were ultimately excluded. The overall death rate (per 100 000 person-years) was 228; 743 in complicated epilepsy (with associated neurodisability or underlying brain condition) and 36 in uncomplicated epilepsy. Thirteen deaths were seizure-related (10 SUDEP, 3 other), accounting for 19% of all deaths. Seizure-related death rates were 43 overall, 122 for complicated epilepsy, and 14 for uncomplicated epilepsy. Death rates from other natural causes were 159, 561, and 9, respectively. Of 48 deaths from other natural causes, 37 were due to pneumonia or other respiratory complications.

CONCLUSIONS

Most excess death in young people with epilepsy is not seizure-related. Mortality is significantly higher compared with the general population in children with complicated epilepsy but not uncomplicated epilepsy. The SUDEP rate was similar to or higher than sudden infant death syndrome rates. In uncomplicated epilepsy, sudden and seizure-related death rates were similar to or higher than rates for other common causes of death in young people (eg, accidents, suicides, homicides). Relating the risk of death in epilepsy to familiar risks may facilitate discussions of seizure-related mortality with patients and families.

The epidemiology of seizure disorders in infancy and childhood: definitions and classifications

Seizures are one of the most common neurological symptoms that occur in infancy and childhood. They represent many different disorders with many different causes. Neonatal seizures occur in ~1.5% of neonates, febrile seizures in 2-4% of young children, and epilepsy in up to 1% of children and adolescents. Seizures provoked by other acute insults such as head trauma also occur although their precise frequency in children is hard to estimate. Ultimately, seizures are symptoms of various neurological insults and conditions. Although neonatal seizures, febrile seizures, and epilepsy overlap to a degree in that children with neonatal or febrile seizures are at increased risk of epilepsy, these different disorders have somewhat different risk factors and their own epidemiology. Furthermore, to the extent that environmental (e.g., infections, malnutrition) and medical system factors (vaccinations, prenatal care) and population genetics play roles, very different risks and patterns are seen in different areas of the world. Within each of these sets of disorders, designated as neonatal or febrile seizures and epilepsy, there are many highly specific conditions that, especially in the case of epilepsy, may have considerable implications for treatment and prognosis and consequently may require care from a specialist.

Anticonvulsant activity of DNS II fraction in the acute seizure models

AIM OF THE STUDY

Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice.

MATERIALS AND METHODS

Different doses (60, 65 and 70mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90mg/kg, s.c. and picrotoxin 3.15mg/kg, s.c.) were used. The mice were observed 45-90min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100mg/kg, i.p.) were tested in the MES test.

RESULTS

The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5mg/kg, i.p. and phenytoin 20mg/kg, i.p.).

CONCLUSIONS

These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile.

Prognosticating acute symptomatic seizures using two different seizure outcomes

PURPOSE

This study examined the profiles and prognosis of first acute symptomatic seizure (ASS). Because seizure recurrences may occur in the setting of a persisting or reemerging acute symptomatic cause or in the setting of an unprovoked seizure, we documented the prognosis of ASS in terms of acute symptomatic seizure (AS) or unprovoked seizure (US) recurrence.

METHODS

We conducted a prospective study of patients with suspected seizures between April 2004 and December 2005. Patients were classified according to medical history taking, routine clinical evaluation, and expert adjudication, and they were followed for a minimum of 2 years or until death. The Kaplan-Meier method and univariate/multivariate statistical analysis were used to determine prognosis.

RESULTS

One hundred five patients with first-ever ASS were identified. For many, first ASS was associated with status epilepticus (29.5%), multiple-onset (>1 seizure within 24 h on day of presentation) (35.2%), and multiple etiologies (22.9%), with a mortality of 30% at 2 years (Kaplan-Meier method). Using AS as outcome, the risk of recurrence following an ASS was 32% at 2 years [mean time to recurrence 20.5 days with epileptiform electroencephalography (EEG) being an independent predictor; p = 0.005, odds ratio (OR) 16, 95% confidence interval (CI) 4.09-62.7]. Using US as outcome, the risk of recurrence following an ASS was 12% at 2 years.

DISCUSSION

Although ASS did not associate with a high rate of US recurrence, we demonstrated that ASS was often followed by another AS. This may have implication for short- to medium-term antiepileptic agent therapy, especially when the acute symptomatic cause takes a long time to treat, is prone to reemergence, or is irreversible.

First seizure - to treat or not to treat?

BACKGROUND

The decision on whether or not to treat a first seizure is dependent on several medical and non-medical factors.

AIMS

In this review, we have summarised the important aspects that determine the advantages and disadvantages of treating a first seizure. We have looked at evidence from randomised controlled trials and key observational studies.

CONCLUSIONS

There is no randomised controlled evidence that treating the aetiology of a first acute symptomatic seizure reduces the risk of relapse, although there are good biological arguments for this. For first unprovoked seizures, immediate treatment reduces the risk of seizure recurrence in the short term, but does not change the long-term prognosis for epilepsy. Other important considerations include the potential adverse events of antiepileptic drugs and socioeconomic factor such as lifestyle changes, driving, employment, financial implications and relationships. Treatment decisions can be made only on an individual patient basis after weighing the pros and cons of each case separately.

Death in epileptic people: a review of Manitoba’s medical examiner’s cases

Studies of cause-specific mortality show that deaths of epileptic people can be classified into those directly or indirectly related to epilepsy; those related to the underlying pathology giving rise to epilepsy; and those unrelated to either epilepsy or its causes. In this descriptive retrospective study, medical examiner's cases that occurred in Manitoba, Canada during 2004 were reviewed. One hundred and seventeen cases (4.06%) had epilepsy in their history. Cause of death was related directly to seizure in 12 cases (10.3%) and indirectly in six cases (5.1%); related to underlying pathology giving rise to epilepsy in 33 cases (28.2%); and unrelated to either of them in 60 cases (51.3%). Cause of death was unknown in six cases (5.1%). The causes of death, in order of frequency, were cardiac pneumonia, cerebrovascular accident and seizure disorder. Manner of death was natural in 86 cases (73.5%), accidental in 19 cases (16.2%), suicidal in five cases (4.3%), undetermined in five cases (4.3%) and homicidal in two cases (1.7%). While the mean age of the deceased persons with a positive history of seizure in this study was about 10 years less than those with a negative history of seizure, there was no significant difference between them in the manner of death. Epileptic people are not at greater risk for accidental death or suicide; however they are at greater risk for drowning. Recently diagnosed cases of epilepsy are at greater risk of dying from seizure or underlying pathology during the first year of their disease.

Mortality in epilepsy

All studies report an increased mortality risk for people with epilepsy compared with the general population. Population-based studies have demonstrated that the increased mortality is often related to the cause of the epilepsy. Common etiologies include neoplasia, cerebrovascular disease, and pneumonia. Deaths in selected cohorts, such as sudden unexpected death in epilepsy (SUDEP), status epilepticus (SE), suicides, and accidents are more frequently epilepsy-related. SUDEP is a particular cause for concern in younger people, and whether and when SUDEP should be discussed with patients with epilepsy remain problematic issues. Risk factors for SUDEP include generalized tonic-clonic seizures, increased seizure frequency, concomitant learning disability, and antiepileptic drug polypharmacy. The overall incidence of SE may be increasing, although case fatality rates remain constant. Mortality is frequently secondary to acute symptomatic disorders. Poor compliance with treatment in patients with epilepsy accounts for a small proportion of deaths from SE. The incidence of suicide is increased, particularly for individuals with epilepsy and comorbid psychiatric conditions. Late mortality figures in patients undergoing epilepsy surgery vary and are likely to reflect differences in case selection. Future studies of mortality should be prospective and follow agreed guidelines to better quantify risk and causation in individual populations.

Death from suicide versus mortality from epilepsy in the epilepsies: a meta-analysis

OBJECTIVE

Epilepsy is associated with an increased risk of mortality, which, however, is rarely due to the epilepsy itself; suicide, on the other hand, is a chief cause of death among persons with epilepsy. We conducted a meta-analysis to compare data reported in representative studies of suicide mortality in epilepsy with data on mortality from epilepsy in the general population.

METHODS

We searched Index Medicus to 2006 through MedLine. We also searched the World Health Statistics Annual to ascertain rates of mortality from epilepsy in the age groups indicated in the studies on patients with epilepsy for specific years and countries.

RESULTS

We selected 30 studies comprising 51,216 persons, 188 of whom committed suicide and died. Results obtained for each study were processed together to calculate, per 100,000 individuals in the general population per year, the mean number of suicide deaths expected in persons with epilepsy with respect to the current prevalence of epilepsy. We found that the number of suicide deaths among persons with epilepsy is the same as the number of deaths from epilepsy, suggesting that the former are not included in mortality rates for epilepsy. Also, we found that, according to data derived from cohorts we selected, 32.5% of all deaths of persons with epilepsy are due to suicide and at least 13.5% of all registered suicides are committed by these persons. Study findings may not generalize to other samples, settings, and treatments, thus perhaps tending to exaggerate the phenomenon actually attainable under broader clinical conditions.

CONCLUSIONS

Our meta-analysis indicates that suicide deaths in persons with epilepsy are a disturbingly frequent phenomenon that should be addressed to reduce mortality among patients with epilepsy dramatically. In particular, mortality rates for persons with epilepsy do not include mortality from suicide, greatly underestimating death rates and the need for suicide prevention strategies for these patients.

Premature mortality in people with epilepsy in rural China: a prospective study

BACKGROUND

In China, few studies have described annual mortality associated with epilepsy in a general population and these have provided a range of 3.0-7.9 deaths per 100,000 people. We calculated the case fatality rate (CFR), proportional mortality rate (PMR), and standardised mortality ratio (SMR) to assess mortality in people with epilepsy in rural China.

METHODS

The target population was people with epilepsy who participated in an assessment of epilepsy management at primary health level in rural China. Neurologists confirmed the diagnosis using strict criteria in all participants who were then treated with phenobarbital. Demographic data and putative cause of death were recorded for each person whose death was reported. PMRs for each cause of death and SMRs were estimated on the basis of the 2004 Chinese population.

FINDINGS

Case fatality rate was 1.4% (35 deaths) among 2455 people with epilepsy. The age-adjusted PMRs for injury, stroke, neoplasm, myocardial infarction, and pneumonia were 30%, 30%, 15%, 6%, and 5%, respectively. The SMR was 3.9 (95% CI 3.8-3.9). Patients aged 15-29 years had higher mortality ratios than did those in other age-groups, with SMRs exceeding 23.

INTERPRETATION

Risk for premature death is three to four times higher in people with epilepsy than in the general Chinese population. Furthermore, the risk in young people with epilepsy in China is much higher than previously reported. Injury, stroke, myocardial infarction, and pneumonia are among the leading putative causes of death in patients with epilepsy in rural China.

Mortality in adults with newly diagnosed and chronic epilepsy: a retrospective comparative study

BACKGROUND

People with epilepsy are at increased risk of premature death compared with the general population. Many clinicians are unsure whether and when this issue should be broached with their patients. We analysed mortality in patients with newly diagnosed and chronic epilepsy over a 20-year period.

METHODS

Patients who attended the epilepsy service at the Western Infirmary in Glasgow, UK between 1981 and 2001, with newly diagnosed epilepsy (n=890) or referred after receiving unsuccessful treatment elsewhere (n=2689) were included in the study. Mortality data were obtained from the General Registrar Office for Scotland. Causes of death were ascertained from death certificates and primary care and health authority records. The two patient cohorts were compared with age-matched and sex-matched Scottish comparison groups. Standardised mortality ratios (SMR) were calculated for each epilepsy type, 10-year age band, and cause of death category.

FINDINGS

Newly diagnosed patients had a 42% increase in mortality (SMR 1.42, 95% CI 1.16-1.72) compared with the comparison group. Increased mortality was recorded in those who had not responded to treatment, with no increase in risk observed in patients who were seizure free. In the chronic epilepsy cohort, there was more than double the expected number of deaths (2.05, 1.83-2.26). The incidence of sudden unexpected death in epilepsy was 1.08 and 2.46 per 1000 patient-years in patients with newly diagnosed and chronic epilepsy, respectively. The greatest excess in mortality was reported in patients younger than 30 years.

INTERPRETATION

Mortality risks and preventive strategies should be discussed with patients with epilepsy when treatment fails or is refused despite recurrent seizures.

Methodologic issues in studies of mortality following epilepsy: measures, types of studies, sources of cases, cohort effects, and competing risks

This paper addresses methodologic issues in studies of mortality, and the impact of these issues in studies of mortality in epilepsy. One important issue is to identify the question: Is it whether epilepsy increases the risk of dying? Or is it whether the underlying condition that led to epilepsy, itself associated with an increased risk for death, is the cause of increased mortality observed in epilepsy? Each measure for estimating mortality requires specific study designs. The mortality rate, case fatality, standardized mortality ratio (SMR) are calculated in prospective or retrospective cohort studies of death in epilepsy. Because the SMR is obtained by indirect standardization, it uses the age- and gender-distribution of the study group with epilepsy, which differs across studies. Thus, the SMR is impossible to compare across studies. The proportionate mortality ratio considers only the proportion of deaths that are due to epilepsy and is useful when denominators are unavailable, often the case in the developing world. Mortality studies in prevalent cohorts of people with epilepsy are compared to those in incident cohorts of epilepsy. The impact of different sources of cases on mortality in epilepsy is discussed. Finally, cohort effects and competing risks are examined. We conclude that the gold standard for studies on mortality should be a population-based cohort of incident cases. Only this type of cohort permits a complete collection of data and the observation of the clinical phase of the disease from the diagnosis of epilepsy to the outcome of the study, death.

Mortality of epilepsy in developed countries: a review

Mortality in people with epilepsy has been studied in many different populations. In population-based incidence cohorts of epilepsy with 7-29 years follow-up, there was up to a threefold increase in mortality, compared to the general population (standardized mortality ratios [SMR] ranged from 1.6 to 3.0). When studies include selected epilepsy populations where patients with frequent and severe seizures are more common, the mortality is even greater. Relative survivorship (RS) following the diagnosis of epilepsy was 91%, 85%, and 83% after 5, 10, and 15 years, respectively. In a population with childhood-onset epilepsy, RS was 94% and 88% after 10 and 20 years. The level of increased mortality is affected by several factors. In idiopathic epilepsy where the causes of seizures are unknown, the results are conflicting. There was no significant increase in mortality in studies from Iceland, France, and Sweden, a barely increased risk in a study from the United Kingdom, and a significantly increased risk in a study from the United States. In contrast, all studies report a significant increased mortality in remote symptomatic epilepsy (standardized mortality ratios [SMRs] ranging from 2.2 to 6.5). The highest mortality is found in patients with epilepsy and neurodeficits present since birth, including mental retardation or cerebral palsy (SMRs ranging from 7 to 50). Mortality is also affected by age, with the highest SMRs in children, the combined effect of low mortality in the reference population, and high mortality in children with neurodeficits and epilepsy. The highest excess mortality is found in the elderly, > or =75 years. A pronounced increase in mortality is found during the first year following the onset of seizures due to underlying severe diseases. The increased mortality remains in different studies 2-14 years following diagnosis. Most of the factors responsible for the increased mortality are related to the underlying disorder causing epilepsy with pneumonia, cerebrovascular disease, and neoplastic disorders (risk remains elevated when primary brain tumors are excluded), as the most frequently recorded causes. The most common direct seizure-related cause of death in adolescents and young adults is sudden unexpected death, which is 24 times more common than in the general population.

Cause-specific mortality in epilepsy

Epilepsy is associated with a two- to three-fold increase in mortality. Studies of cause-specific mortality show that deaths may be classified into those that are directly or indirectly related to epilepsy, those that are related to the underlying pathology giving rise to epilepsy, and those that are unrelated to both epilepsy and its causes. Overall, direct epilepsy related deaths are infrequent. Pneumonia, especially in the elderly, central nervous system (CNS) and non-CNS neoplasias, and cerebrovascular disease are frequent causes of death. Suicides, accidental deaths, and ischemic heart disease do not appear to be significant contributors to mortality in community-based studies. In hospital/institution-based analyses, epilepsy-related deaths are common and sudden unexpected death in epilepsy (SUDEP) may account for up to 17% of all deaths in epilepsy. A small proportion of these deaths may be witnessed and most such witnessed deaths occur in relation to convulsive seizures. The exact pathogenetic mechanisms are unknown although it is very probable that lack of seizure control is an important risk factor. Patients who continue to suffer seizures appear to have an almost 40 times higher risk of mortality than those in remission.

Mortality after Epilepsy Surgery

Mortality rates are higher in people with refractory epilepsy than in the general population. We assessed mortality rates in a prospectively followed cohort who had epilepsy surgery, to examine the factors related to mortality and to assess the relationship between seizure control and mortality. Five hundred eighty-three patients were evaluated. Mortality was strongly related to seizure control (p = 0.001), with 18 deaths observed in patients with recurrent seizures (mortality rate = 11.4 per 1,000 person-years) and 1 death in patients with no recurrent seizures (mortality rate = 0.85 deaths per 1,000 person-years). Patients with generalized epilepsy who had corpus callosotomy had a higher mortality rate than patients who had resective or transective surgery. The side of surgery and gender did not influence mortality rates. The standardized mortality ratio was 5.75 for patients with recurrent seizures and was significantly higher for females than males. These data show that the excess mortality associated with refractory epilepsy is eliminated after epilepsy surgery when seizures are abolished and suggest that epilepsy surgery reduces the risk of epilepsy-associated death.

Mortality in Patients with a First Unprovoked Seizure

PURPOSE

The mortality after a first epileptic seizure is affected by the source of cases, the intensity of the diagnostic work-up, the type and the presumed etiology of the seizure, the length of follow-up, and the modalities of data collection (retrospective vs. prospective). We review the four studies of this topic.

METHODS

Four studies have been identified which focused on the mortality of the first unprovoked seizures or the first afebrile (provoked or unprovoked) seizure. These included two population-based surveys, one clinic-based community survey, and a randomized clinical trial on the treatment of the first unprovoked generalized tonic-clonic seizure.

RESULTS

A standardized mortality ratio (SMR) of 2.3 (95% confidence interval, CI 1.5-3.3) for unprovoked first seizures was found in a retrospective cohort study in the population of Rochester, Minnesota. The SMR was higher during the first year after the seizures to progressively decrease thereafter. Acute symptomatic seizures carried the higher risk, followed by remote symptomatic seizures, while idiopathic and cryptogenic seizures carried no risk. The increased SMR found in women and in patients aged 0-19 years enrolled in the randomized trial differs from that seen in other mortality studies in epilepsy (SMR being highest in the youngest age groups) and may be a chance finding.

CONCLUSIONS

Mortality is increased in patients with a first unprovoked seizure, particularly during the first year after the seizure. This increased mortality is associated with known etiology of the seizure, and is not present when etiology is unknown.

Seizure Aggravation in Idiopathic Generalized Epilepsies

Seizures in the idiopathic generalized epilepsies (IGEs) usually remit completely with antiepileptic drugs (AEDs). Occasionally, however, they may be aggravated by AEDs. Before attributing exacerbation of seizures to an AED, alternative explanations need to be excluded. These include natural fluctuation of seizures, irregular compliance, maladjustment to the disease, comorbid illness, and development of tolerance. Aggravation may be due to a paradoxical reaction or drug-induced encephalopathy, sedative effects, or inappropriate use of a drug; and this need to be established, as it will guide management. An important caveat is that most data on aggravation of generalized seizures are based on anecdotal case reports or case series. Whether considering efficacy or aggravation, the interpretation of data from uncontrolled studies and case reports must be treated with caution. In practice, despite the fact that clear evidence is lacking, the possibility of seizure aggravation must be considered when treating people with IGEs. Predictive factors for seizure aggravation in a particular patient with a specific drug are yet to be fully defined. It is paramount to classify seizure type correctly in all patients. If this is not possible, a broad-spectrum AED should be used. Drugs that modulate Na+-channels and GABAergic drugs seem to be more prone to aggravating seizures, and therefore are best avoided in the initial management of IGE. Further studies are required to elucidate this phenomenon in full. It is interesting to speculate that paradoxical responses to AEDs may have pharmacogenetic value, serving as tools for a more precise and useful characterization of the epilepsies.