Prevalence, incidence, and classification of epilepsy in the Faroes

Causes and classification of first unprovoked seizures and newly-diagnosed epilepsy in a defined geographical area- an all-comers analysis

PURPOSE

The ILAE recently updated the operational definition of epilepsy and the classifications of seizures and epilepsy incorporating aetiology into the classification framework. To date, these classifications have not been applied in any whole population incidence study.

METHODS

Multiple overlapping methods of case identification were applied to a defined geographical area (population 542,868 adults and children) to identify all first unprovoked seizures and new diagnosis of epilepsy presenting during the calendar year 2017. The 2017 ILAE classification frameworks were applied. Incidence was age-standardised to the 2013 Standard European Population.

RESULTS

The annual incidence per 100,000 population was 44 for focal epilepsy, 6.8 for generalized epilepsy and 10.9 for unclassified epilepsy (age standardized 56, 6.9 and 11.4, respectively). Focal epilepsy was diagnosed in all age groups, though incidence increased in those ≥55 years of age. Primary generalised epilepsy accounted for 10% (n = 32) of newly diagnosed epilepsy. The most frequently diagnosed aetiology was structural (54%, n = 182). In 30% (n = 102) of newly diagnosed epilepsy, aetiology was not established.

CONCLUSION

We report on the causes of incident first unprovoked seizures and epilepsy in accordance with recently updated ILAE definitions and classification systems employing standard diagnostic investigations. We report a higher proportion of structural aetiology than previous studies, which may reflect incorporation of imaging in aetiology classification. Despite improved access to diagnostic testing, aetiology of a large fraction of first seizures and newly diagnosed epilepsy remains unknown.

Epilepsy lifetime prevalence in Iran: a large population- based national survey

Epilepsy has garnered increased public health focus because patients who suffer from epilepsy experience pronounced and persistent health and socioeconomic disparities despite treatment and care advances. The epidemiology of epilepsy is diverse in different countries and regions. This nationwide population-based cross-sectional study was conducted to determine the life time prevalence and health related factors of epilepsy for the first time in Iran through a two-phase door-to-door survey method. In phase I, a screening for epilepsy was performed on 68,035 people. Then in phase II, after the neurological evaluation of participants and reviewing medical records, 1130 subjects with epilepsy was confirmed. The life time prevalence of epilepsy was achieved to be 16.6 per 1000 people (95% CI 15.4-17.8) with the average age onset 19.1 ± 21.1 (active prevalence 9.5 per 1000 people). Focal seizure (59.3%), generalized epilepsy (38%) and unknown types of epilepsy (2.7%) were detected among participants. The overall life time prevalence of febrile convulsion was 4.1 per 1000 people. The frequency of attacks per year and per month were 3.0 ± 1.6 and 0.5 ± 0.1, respectively. Age-specific life time prevalence was highest among the age group of 15-19 years old [32.7 per 1000 persons (95% CI 29.1-36.8)] and it was higher in male (53.8%) than female (46.2%) participants. Our results showed that the life time prevalence of epilepsy in Iran is higher than worldwide average.

Incidence of first seizures, epilepsy, and seizure mimics in a geographically defined area

OBJECTIVE

To determine the incidence of first seizures, epilepsy, and seizure mimics in a geographically defined area using the updated 2014 International League Against Epilepsy (ILAE) definition, which allows an epilepsy diagnosis after a single seizure when the risk of further seizures over the next 10 years is ≈60% or greater. This replaced the 1993 definition by which epilepsy was diagnosed when a person had ≥2 seizures separated by 24 hours.

METHODS

Using multiple overlapping methods of case ascertainment followed by individual case classification by an epileptologist, we identified all first seizures, new diagnosis of epilepsy, and seizure mimics occurring in a defined geographic area (population 542,868) from January 1, 2017, to December 31, 2017. Incidence was age standardized to the Standard European Population. We compared incidence rates using the 2014 and 1993 ILAE definitions.

RESULTS

When the 2014 ILAE definition of epilepsy was applied, the incidence of new diagnosis of epilepsy was 62 per 100,000 (age standardized 74) compared to 41 per 100,000 (age standardized 48) when the 1993 definition was applied, and the difference was more pronounced at older ages. The incidence of all first seizures and of seizure mimics was 102 per 100,000 (age standardized 123) and 94 per 100,000 (age standardized 111), respectively. The most frequently encountered seizure mimic was syncope.

CONCLUSION

Application of the 2014 ILAE definition of epilepsy resulted in a higher incidence of new diagnosis of epilepsy compared to the 1993 definition. The incidence of seizure mimics almost equals that of all first seizures. Seizures, epilepsy, and seizure mimics represent a significant burden to health care systems.

Incidence of early-onset epilepsy: A prospective population-based study

PURPOSE

The first five years of life reflect a critical period of development prior to formal education yet few epidemiological studies focus on children with early-onset epilepsy (CWEOE; onset <60 months). This study aimed to determine early-onset epilepsy incidence using a comprehensive case identification strategy, and examined socioeconomic status (SES) and ethnicity as risk factors.

METHODS

Through a prospective, population-based study, newly diagnosed CWEOE from Fife and Lothian, Scotland, were identified using multiple-source, active surveillance capture-recapture between May 2013 and June 2015. Crude, ascertainment-adjusted, age-adjusted, age- and gender-specific, and epilepsy-type incidence rates were determined. Risk ratios (RR) were calculated to examine SES and ethnicity as risk factors.

RESULTS

59 (36 Male) CWEOE were identified. Ascertainment was 98% (95% CI 94-103). Crude annual incidence of epilepsy in children 0-59 months was 60.2 (95% CI 44.8-75.5) per 100,000 per year; ascertainment-adjusted annual incidence was 61.7 (95% CI 46.2-77.3) per year. Cumulative incidence of West Syndrome/Infantile Spasms was 6.7 per 10,000 live births (95% CI 3.6-12.3). Aetiology was unknown in almost two-thirds of CWEOE. Compared to White-British Isles (BI) children, Asian children (RR 2.6 [95% CI 1.2-5.7], p = .02) and White-non-BI children (RR 2.5 [95% CI 1.2-5.2], p = .02) had increased risk. SES was not a risk factor.

CONCLUSION

The high incidence of early-onset epilepsy is similar to previous studies and demonstrates a substantial disease burden. Cause of epilepsy remains unknown in almost two thirds of CWEOE. Ethnicity but not SES affects early-onset epilepsy risk.

ABCB1 Polymorphisms and Drug-Resistant Epilepsy in a Tunisian Population

Background

Epilepsy is one of the most common neurological disorders with about 30% treatment failure rate. An interindividual variations in efficacy of antiepileptic drugs (AEDs) make the treatment of epilepsy challenging, which can be attributed to genetic factors such as ATP-Binding Cassette sub-family B, member1 (ABCB1) gene polymorphisms.

Objective

The main objective of the present study is to evaluate the association of ABCB1 C1236T, G2677T, and C3435T polymorphisms with treatment response among Tunisian epileptic patients.

Materials and Methods

One hundred epileptic patients, originated from north of Tunisia, were recruited and categorized into 50 drug-resistant and 50 drug-responsive patients treated with antiepileptic drugs (AEDs) as per the International League Against Epilepsy. DNA of patients was extracted and ABCB1 gene polymorphisms studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

The C1236T, G2677T, and C3435T polymorphisms were involved into AED resistance. Significant genotypic (C1236T TT (p ≤ 0.001); G2677T TT (p = 0.001); C3435T TT (p ≤ 0.001)) and allelic associations (C1236T T (3.650, p ≤ 0.001); G2677TT (1.801, p = 0.044); C3435T T (4.730, p ≤ 0.001)) with drug resistance epilepsy (DRE) were observed. A significant level of linkage disequilibrium (LD) was also noted between ABCB1 polymorphisms. Patients with the haplotypes CT and TT (C1236T-G2677T); GT, TC, and TT (G2677T-C3435T); CT and TT (C1236T-C3435T); CTT, TTC, TGT, and TTT (C1236T-G2677T-C3435T) were also significantly associated to AED resistance.

Conclusions

The response to antiepileptics seems to be modulated by TT genotypes, T alleles, and the predicted haplotypes for the tested SNPs in our population. Genetic analysis is a valuable tool for predicting treatment response and thus will contribute to personalized medicine for Tunisian epileptic patients.

Latitudinal differences on the global epidemiology of infantile spasms: systematic review and meta-analysis

BACKGROUND

Infantile spasms represent the catastrophic, age-specific seizure type associated with acute and long-term neurological morbidity. However, due to rarity and heterogenous determination, there is persistent uncertainty of its pathophysiological and epidemiological characteristics. The purpose of the current study was to address a historically suspected latitudinal basis of infantile spasms incidence, and to interrogate a geographical basis of epidemiology, including the roles of latitude and other environmental factors, using meta-analytic and -regression methods.

METHODS

A systematic search was performed in Ovid MEDLINE and Embase for primary reports on infantile spasms incidence and prevalence epidemiology.

RESULTS

One thousand fifteen studies were screened to yield 54 eligible publications, from which 39 incidence figures and 18 prevalence figures were extracted. The pooled incidence was 0.249 cases/1000 live births. The pooled prevalence was 0.015 cases/1000 population. Univariate meta-regression determined a continental effect, with Europe demonstrating the highest onset compared from Asia (OR = 0.51, p = 0.004) and from North America (OR = 0.50, p = 0.004). Latitude was also positively correlated with incidence globally (OR = 1.02, p < 0.001). Sub-analyses determined a particularly elevated Scandinavian incidence compared to the rest of world (OR = 1.88, p < 0.001), and lack of latitudinal effect with Scandinavian exclusion (p = 0.10). Metrics of healthcare quality did not predict incidence. Multiple meta-regression determined that latitude was the key predictor of incidence (OR = 1.02, p = 0.001).

CONCLUSIONS

This is the first systematic epidemiological study of infantile spasms. Limitations included lack of Southern hemispheric representation, insufficient study selection and size to support some sub-continental analyses, and lack of accessible ethnic and healthcare quality data. Meta-analyses determined a novel, true geographical difference in incidence which is consistent with a latitudinal and/or ethnic contribution to epileptogenesis. These findings justify the establishment of a global registry of infantile spasms epidemiology to promote future systematic studies, clarify risk factors, and expand understanding of the pathophysiology.

Sex differences in the anticonvulsant activity of neurosteroids

Epilepsy is one of the leading causes of chronic neurological morbidity worldwide. Acquired epilepsy may result from a number of conditions, such as brain injury, anoxia, tumors, stroke, neurotoxicity, and prolonged seizures. Sex differences have been observed in many seizure types; however, some sex-specific seizure disorders are much more prevalent in women. Despite some inconsistencies, substantial data indicates that sensitivity to seizure stimuli differs between the sexes. Men generally exhibit greater seizure susceptibility than women, whereas many women with epilepsy experience a cyclical occurrence of seizures that tends to center around the menstrual period, which has been termed catamenial epilepsy. Some epilepsy syndromes show gender differences with female predominance or male predominance. Steroid hormones, endogenous neurosteroids, and sexually dimorphic neural networks appear to play a key role in sex differences in seizure susceptibility. Neurosteroids, such as allopregnanolone, reflect sex differences in their anticonvulsant activity. This Review provides a brief overview of the evidence for sex differences in epilepsy and how sex differences influence the use of neurosteroids in epilepsy and epileptogenesis. © 2016 Wiley Periodicals, Inc.

Prevalence of juvenile myoclonic epilepsy in people <30 years of age-A population-based study in Norway

OBJECTIVE

Despite juvenile myoclonic epilepsy (JME) being considered one of the most common epilepsies, population-based prevalence studies of JME are lacking. Our aim was to estimate the prevalence of JME in a Norwegian county, using updated diagnostic criteria.

METHODS

This was a cross-sectional study, based on reviews of the medical records of all patients with a diagnosis of epilepsy at Drammen Hospital in the period 1999-2013. The study population consisted of 98,152 people <30 years of age. Subjects diagnosed with JME, unspecified genetic generalized epilepsy, or absence epilepsy were identified. All of these patients were contacted and asked specifically about myoclonic jerks. Electroencephalography (EEG) recordings and medical records were reevaluated for those who confirmed myoclonic jerks. Information about seizure onset was obtained from the medical records, and annual frequency of new cases was estimated.

RESULTS

A total of 55 subjects fulfilled the diagnostic criteria for JME. The point prevalence was estimated at 5.6/10,000. JME constituted 9.3% of all epilepsies in the age group we investigated. Of subjects diagnosed with either unspecified genetic generalized epilepsy or absence epilepsy, 21% and 12%, respectively, had JME. We identified 21 subjects with JME (38%) who had not been diagnosed previously. Six subjects (11%) had childhood absence epilepsy evolving into JME. Between 2009 and 2013, the average frequency of JME per 100,000 people of all ages per year was estimated at 1.7.

SIGNIFICANCE

A substantial portion of people with JME seem to go undiagnosed, as was the case for more than one third of the subjects in this study. By investigating subjects diagnosed with unspecified genetic generalized epilepsy or absence epilepsy, we found a prevalence of JME that was considerably higher than previously reported. We conclude that JME may go undiagnosed due to the underrecognition of myoclonic jerks. To make a correct diagnosis, clinicians need to ask specifically about myoclonic jerks.

Epidemiology of epilepsy

Epilepsy is a burden affecting no fewer than 50 million patients worldwide. It is a heterogeneous group of disorders comprising both common and very rare forms, thus rendering its epidemiological investigations rather difficult. Moreover, making an epilepsy diagnosis per se can be challenging due to an evolving system of classification, and its dependency on local habits and culture. Any attempt at meta-analyses must consider such biases when pooling data from different centers and countries. Differentiating a contextual seizure from chronic epilepsy is every epileptologist's daily mission, yet it is also crucial for achieving a proper estimation of the epidemiology of epilepsy. Our present objective was to provide an overview of the epidemiology of both syndromic and non-syndromic epilepsy. Most epileptic syndromes tend to be rare and, thus, the feasibility of epidemiological quantification in populations is also addressed. Regarding its prevalence and cost, epilepsy deserves greater attention than it generally receives, as it appears to continue to be a condition under persistent taboos.

Adult Prevalence of Epilepsy in Spain: EPIBERIA, a Population-Based Study

BACKGROUND

This study assesses the lifetime and active prevalence of epilepsy in Spain in people older than 18 years.

METHODS

EPIBERIA is a population-based epidemiological study of epilepsy prevalence using data from three representative Spanish regions (health districts in Zaragoza, Almería, and Seville) between 2012 and 2013. The study consisted of two phases: screening and confirmation. Participants completed a previously validated questionnaire (EPIBERIA questionnaire) over the telephone.

RESULTS

A total of 1741 valid questionnaires were obtained, including 261 (14.99%) raising a suspicion of epilepsy. Of these suspected cases, 216 (82.75%) agreed to participate in phase 2. Of the phase 2 participants, 22 met the International League Against Epilepsy's diagnostic criteria for epilepsy. The estimated lifetime prevalence, adjusted by age and sex per 1,000 people, was 14.87 (95% CI: 9.8-21.9). Active prevalence was 5.79 (95% CI: 2.8-10.6). No significant age, sex, or regional differences in prevalence were detected.

CONCLUSIONS

EPIBERIA provides the most accurate estimate of epilepsy prevalence in the Mediterranean region based on its original methodology and its adherence to ILAE recommendations. We highlight that the lifetime prevalence and inactive epilepsy prevalence figures observed here were compared to other epidemiological studies.

Epidemiology and long-term Turku outcome of childhood-onset epilepsy and mortality. Personal experiences. Part I

Introduction.Epidemiological studies on epilepsy were long based, with few exceptions, on hospital and institution patients with a subsequent bias toward more difficult cases and the reported prevalence and incidence rates were often obviously too low. Few data are available on the temporal changes in the incidence of epilepsy.

Aim.To study the prevalence and incidence in an unselected child population including all the children living either in the society or in the institution, temporal changes in the incidence and mortality through five decades.

Methods.The most important personal data were reviewed and compared with the relevant data of other investigators.

Results and discussion.The prevalence of epilepsy in our study was 3.2/1000, quite obviously true for the contemporary methodology and well comparable with 3.4–4.2/1000 of other relevant studies published about two decades later and using a more advanced methodology. Similarly, the incidence of 35/100 000, ascertained in two Finnish studies, was comparable with the relevant contemporary literature data. Another study of ours shows that, probably associated with the people “coming from the shadows” and an improved diagnostic methodology, the incidence of childhood epilepsy has increased and is now 60–70/100 000. However, the incidence of childhood epilepsy shows an obvious decreasing trend in the first two decades of the 2000s.

Conclusions.The incidence of childhood epilepsy, in all probability true for the contemporary methodology, was lower than it is now, but it now again shows a decreasing trend.

Myasthenia gravis incidence in a general North Atlantic isolated population

OBJECTIVE

There are no previous studies undertaken about myasthenia gravis in the Faroe Islands. The aim of this study was to establish the incidence of onset of this disease in the Faroese population.

METHOD

Patients were ascertained and registered prospectively from 1986 to 2013 when they were examined at the Neurological Clinic of the Faroese National Hospital or at a private neurological practice, which constitutes all the available neurological services in the Faroe Islands.

RESULT

Twelve new diagnoses were made over a 27-year period, providing an incidence density rate of 9.4 per million person-years (95% confidence limit 4.9-16.5). At presentation, nine of 12 patients had generalized myasthenia gravis and two patients had pure ocular disease, and in one patient, the symptoms were restricted to the bulbo-facial muscles. The sex ratio was 2:1, F/M. In nine of the cases, a positive result of acetylcholine receptor antibody assay was documented. In all patients, there was a beneficial response to anticholinesterase administration.

CONCLUSION

The result yielded no strong evidence of a difference in incidence between that found in the Faroe Islands and those in most European studies, apart from recent studies from London, UK; Norway; Spain, and Italy in which incidences from 21 to 30 per million person-years had been reported.

USL255 extended-release topiramate for the treatment of epilepsy

USL255 is a once-daily, extended-release formulation of the well-established antiepileptic drug topiramate that was recently approved by the US FDA. As a capsule formulation, USL255 can be swallowed intact or opened and sprinkled onto soft food for patients with swallowing difficulties, including children (≥2 years old) and older patients. USL255 has been evaluated in seven key Phase I and III studies. Compared with immediate-release topiramate taken twice daily, once-daily USL255 provides equivalent topiramate exposure with a 26% reduction in plasma fluctuations. A multinational, Phase III, randomized, double-blind, placebo-controlled clinical trial in patients with refractory partial-onset seizures (PREVAIL) demonstrated that USL255 (200 mg/day) significantly improved seizure control and clinical outcomes versus placebo. USL255 is generally safe and well-tolerated, with a low incidence of neuropsychiatric and neurocognitive adverse events. These data suggest that USL255 may provide a useful treatment option for seizure control with convenient once-daily dosing.

Prevalence and clinical characteristics of epilepsy in the South of Spain

PURPOSE

Epilepsy is a common neurological disorder found in all societies. There are extensive epidemiologic studies of different European areas. However, not much information about the South-West of Europe exists. In Málaga, Health Care is free and there are only two public hospitals with Neurological Services that assist Eastern or Western areas depending on the case. The purpose is to estimate the epidemiology in Málaga through a hospital-based study and compare it to the other European studies.

METHODS

Review on the hospital data base and gathering of consecutive patients with a diagnosis of active epilepsy served by the Epilepsy outpatient clinic in Virgen de la Victoria Hospital throughout a year.

RESULTS

2 281 patients fulfilled the criteria and 515 patients were recruited in order to study the epidemiologic characteristics. Male gender and focal onset seizures predominate (75.5%). Medium age 40. 58% of patients have been seizure-free in the last year. Known etiology in half of the patients. 54% of patients are treated with monotherapy. Valproic acid is the commonest drug. Other epidemiologic and demographic important data are provided. Data are analysed and compared to other European studies.

CONCLUSIONS

Prevalence rate in Western Málaga is 4.79 cases/1000 inhabitants. Characteristics of the sample are similar to those of other European studies. Although this is a hospital-based study, the particular characteristics of the Health Care System in our region enable us to gather real data concerning epidemiology and prevalence.

Clinical characteristics and use of antiepileptic drugs among adolescents with uncomplicated epilepsy at a referral center in Novi Sad, Serbia

The study aimed to investigate the type and etiology of epileptic seizures and the use of antiepileptic drugs for the treatment of various forms of epileptic seizures among adolescents with active but uncomplicated epilepsy at a tertiary referral center in Novi Sad, Serbia. The study design was cross sectional. Data were obtained from patients and medical records. A total of 103 adolescents (39 males and 64 females) with active but uncomplicated epilepsy were included. Patients with primary generalized seizures had significantly better control of epilepsy than those with partial seizures with or without secondary generalization. A total of 80 (77.7%) adolescents had no known underlying etiology based on initial diagnosis and evaluation. All adolescents were classified into known idiopathic syndromes (54.4%), non-classifiable cryptogenic etiology (23.3%), and secondary epilepsy attributed to MRI-identified lesions (22.3%). Eighty-eight percent of adolescents were taking monotherapy and 64.8% of these were taking valproate. New antiepileptic drugs (AEDs), topiramate and lamotrigine, the only drugs available free of charge at the Serbian market, were used in 19.4% of patients. A total of 57.3% adolescents were seizure-free, 24.2% had occasional seizures, and 18.5% had seizures despite AED treatment.

Cost of disorders of the brain in Europe 2010

BACKGROUND

The spectrum of disorders of the brain is large, covering hundreds of disorders that are listed in either the mental or neurological disorder chapters of the established international diagnostic classification systems. These disorders have a high prevalence as well as short- and long-term impairments and disabilities. Therefore they are an emotional, financial and social burden to the patients, their families and their social network. In a 2005 landmark study, we estimated for the first time the annual cost of 12 major groups of disorders of the brain in Europe and gave a conservative estimate of €386 billion for the year 2004. This estimate was limited in scope and conservative due to the lack of sufficiently comprehensive epidemiological and/or economic data on several important diagnostic groups. We are now in a position to substantially improve and revise the 2004 estimates. In the present report we cover 19 major groups of disorders, 7 more than previously, of an increased range of age groups and more cost items. We therefore present much improved cost estimates. Our revised estimates also now include the new EU member states, and hence a population of 514 million people.

AIMS

To estimate the number of persons with defined disorders of the brain in Europe in 2010, the total cost per person related to each disease in terms of direct and indirect costs, and an estimate of the total cost per disorder and country.

METHODS

The best available estimates of the prevalence and cost per person for 19 groups of disorders of the brain (covering well over 100 specific disorders) were identified via a systematic review of the published literature. Together with the twelve disorders included in 2004, the following range of mental and neurologic groups of disorders is covered: addictive disorders, affective disorders, anxiety disorders, brain tumor, childhood and adolescent disorders (developmental disorders), dementia, eating disorders, epilepsy, mental retardation, migraine, multiple sclerosis, neuromuscular disorders, Parkinson's disease, personality disorders, psychotic disorders, sleep disorders, somatoform disorders, stroke, and traumatic brain injury. Epidemiologic panels were charged to complete the literature review for each disorder in order to estimate the 12-month prevalence, and health economic panels were charged to estimate best cost-estimates. A cost model was developed to combine the epidemiologic and economic data and estimate the total cost of each disorder in each of 30 European countries (EU27+Iceland, Norway and Switzerland). The cost model was populated with national statistics from Eurostat to adjust all costs to 2010 values, converting all local currencies to Euro, imputing costs for countries where no data were available, and aggregating country estimates to purchasing power parity adjusted estimates for the total cost of disorders of the brain in Europe 2010.

RESULTS

The total cost of disorders of the brain was estimated at €798 billion in 2010. Direct costs constitute the majority of costs (37% direct healthcare costs and 23% direct non-medical costs) whereas the remaining 40% were indirect costs associated with patients' production losses. On average, the estimated cost per person with a disorder of the brain in Europe ranged between €285 for headache and €30,000 for neuromuscular disorders. The European per capita cost of disorders of the brain was €1550 on average but varied by country. The cost (in billion €PPP 2010) of the disorders of the brain included in this study was as follows: addiction: €65.7; anxiety disorders: €74.4; brain tumor: €5.2; child/adolescent disorders: €21.3; dementia: €105.2; eating disorders: €0.8; epilepsy: €13.8; headache: €43.5; mental retardation: €43.3; mood disorders: €113.4; multiple sclerosis: €14.6; neuromuscular disorders: €7.7; Parkinson's disease: €13.9; personality disorders: €27.3; psychotic disorders: €93.9; sleep disorders: €35.4; somatoform disorder: €21.2; stroke: €64.1; traumatic brain injury: €33.0. It should be noted that the revised estimate of those disorders included in the previous 2004 report constituted €477 billion, by and large confirming our previous study results after considering the inflation and population increase since 2004. Further, our results were consistent with administrative data on the health care expenditure in Europe, and comparable to previous studies on the cost of specific disorders in Europe. Our estimates were lower than comparable estimates from the US.

DISCUSSION

This study was based on the best currently available data in Europe and our model enabled extrapolation to countries where no data could be found. Still, the scarcity of data is an important source of uncertainty in our estimates and may imply over- or underestimations in some disorders and countries. Even though this review included many disorders, diagnoses, age groups and cost items that were omitted in 2004, there are still remaining disorders that could not be included due to limitations in the available data. We therefore consider our estimate of the total cost of the disorders of the brain in Europe to be conservative. In terms of the health economic burden outlined in this report, disorders of the brain likely constitute the number one economic challenge for European health care, now and in the future. Data presented in this report should be considered by all stakeholder groups, including policy makers, industry and patient advocacy groups, to reconsider the current science, research and public health agenda and define a coordinated plan of action of various levels to address the associated challenges.

RECOMMENDATIONS

Political action is required in light of the present high cost of disorders of the brain. Funding of brain research must be increased; care for patients with brain disorders as well as teaching at medical schools and other health related educations must be quantitatively and qualitatively improved, including psychological treatments. The current move of the pharmaceutical industry away from brain related indications must be halted and reversed. Continued research into the cost of the many disorders not included in the present study is warranted. It is essential that not only the EU but also the national governments forcefully support these initiatives.

Multiple sclerosis incidence in the Faroe Islands 1986-2007

OBJECTIVE

Epidemiological studies of the isolated Faroese population in 1945 identified a high annual incidence of multiple sclerosis (MS) of 10/100,000. At the time, there was speculation that the disease was brought to the country by British occupation forces resident in the islands from 1940 to 1945. The objective of the current study is to determine the incidence of diagnosis of MS in the Faroe Islands during the period 1986-2007.

METHODS

All patients in the Faroe Islands diagnosed with MS from July 1, 1986 to July 1, 2007 are documented in the current longitudinal, prospective study. The diagnosis is based on clinical observation, magnetic resonance imaging scanning, cerebrospinal fluid tests, and visual evoked potential response testing.

RESULTS

The incidence of MS during the period 1986-2007 is 4.5/100,000 annually. This is generally of the same order of magnitude as other research findings in Scandinavia and Iceland. The incidence of MS from 1986 to 2007 is about double the incidence in the Faroe Islands for the period from 1940 to 1986, calculated to be 2.7/100,000 annually.

CONCLUSION

The observed incidence of MS in the Faroe Islands, where the population is genetically homogeneous and where the diet exposes the population to neuro-toxic contamination, is at the same level as found in other high-risk regions. The former detected epidemics of MS in Faroe Islands seems apparently to have leveled out and could not be recognized in the recent period covered by the present survey.

The descriptive epidemiology of epilepsy-a review

Epilepsy is a chronic disease experienced by millions and a cause of substantial morbidity and mortality. This review summarizes prevalence and incidence studies of epilepsy that provided a clear definition of epilepsy and could be age-adjusted: requirements if comparisons across studies are to be made. Although few exceptions, age-adjusted prevalence estimates from record-based studies (2.7-17.6 per 1000), are lower than those from door-to-door surveys (2.2-41.0 per 1000). Age-adjusted incidence ranged from 16 to 51 per 100,000, with one exception in Chile, where incidence was 111 per 100,000. Variation in reported prevalence and incidence may be related to factors such as access to health care, regional environmental exposures, or socioeconomic status. A higher proportion of epilepsy characterized by generalized seizures was reported in most prevalence studies. Epilepsy characterized by partial seizures accounted for 20-66% of incident epilepsies. Virtually all prevalence and incidence studies report a preponderance of seizures of unknown cause. Additional prevalence studies are needed in regions where data does not exist, and additional incidence studies in all regions. Interpretation of differences in prevalence and incidence will require understanding of the role of cultural, social and economic factors influencing epilepsy and its care.

The incidence rate of seizures in relation to BMI in UK adults

A retrospective cohort study using the data from The Health Improvement Network (THIN) database in the United Kingdom was conducted to examine the incidence rates of seizures across different BMI levels in the adult population aged > or = 18 years. Poisson regression was used to examine the relationship between BMI and seizures. The overall incidence rate of seizures was found to be 31.2 cases per 100,000 person-years. The incidence rate of seizures (cases per 100,000 person-years) in obese patients (BMI > or = 30 kg/m2) was 34.8 (95% confidence interval (CI), 23.1, 46.4), comparable to that in patients with normal weight (BMI between 18.5 and 24.9 kg/m2) (35.8, 95% CI (26.6, 44.9)). In contrast, underweight patients (< 18.5 kg/m2) or extremely obese (> or = 40 kg/m2) patients tended to have higher incidence rates than those with normal weight. After adjustment for age, gender, and smoking status, compared to patients with normal weight, those who were underweight or extremely obese had a rate ratio (RR) for seizures of 1.6 (95% CI (0.7, 3.8)) and 1.7 (95% CI (0.7, 3.9)), respectively. To date, we have not found any study that examines the associations between BMI or obesity and seizures. In this study, the incidence rates of seizures in the extremely obese and underweight patients tended to be higher than that in the normal-weight patients.

Estimating the cost of epilepsy in Europe: a review with economic modeling

PURPOSE

Based on available epidemiologic, health economic, and international population statistics literature, the cost of epilepsy in Europe was estimated.

METHODS

Europe was defined as the 25 European Union member countries, Iceland, Norway, and Switzerland. Guidelines for epidemiological studies on epilepsy were used for a case definition. A bottom-up prevalence-based cost-of-illness approach, the societal perspective for including the cost items, and the human capital approach as valuation principle for indirect costs were used. The cost estimates were based on selected studies with common methodology and valuation principles.

RESULTS

The estimated prevalence of epilepsy in Europe in 2004 was 4.3-7.8 per 1,000. The estimated total cost of the disease in Europe was euro15.5 billion in 2004, indirect cost being the single most dominant cost category (euro8.6 billion). Direct health care costs were euro2.8 billion, outpatient care comprising the largest part (euro1.3 billion). Direct nonmedical cost was euro4.2 billion. That of antiepileptic drugs was euro400 million. The total cost per case was euro2,000-11,500 and the estimated cost per European inhabitant was euro33.

CONCLUSIONS

Epilepsy is a relevant socioeconomic burden at individual, family, health services, and societal level in Europe. The greater proportion of such burden is outside the formal health care sector, antiepileptic drugs representing a smaller proportion. Lack of economic data from several European countries and other methodological limitations make this report an initial estimate of the cost of epilepsy in Europe. Prospective incidence cost-of-illness studies from well-defined populations and common methodology are encouraged.

Cost of disorders of the brain in Denmark

The cost of brain disorders in Denmark is unknown and such information is important to decision makers. The aims of the study were to estimate the total number of subjects with brain diseases, and the associated direct and indirect expenses in Denmark. This was part of a larger pan-European study commissioned by the European Brain Council, which is an international collaboration of organizations within psychiatry, neurology, neurosurgery, neuro-research and patient organizations. The project provided the best possible estimates of the expenses for brain diseases based on available international scientific literature. The present study presents results for Denmark. There were an estimated 1.4 million Danish citizens who in 2004 had one of the selected 12 brain diseases, equivalent to one quarter of the total population. Anxiety disorders and migraine were the two most frequent diseases with 500,000 and 340,000 patients, respectively. The total expenses for all selected brain diseases were 37.3 billion DKR. Affective disorders, dependency, dementia and stroke were the most costly diseases. An estimated 12% of all direct costs in the Danish health system were spent on brain diseases; 9% of the total drug consumption was used for treatment of brain diseases. Expenses to brain diseases constituted 3% of the gross domestic product. Brain disorders are very prevalent in Denmark and they cause high societal and personal cost.

Age-specific prevalence of epilepsy in Oppland County, Norway

OBJECTIVE - To assess the prevalence of epilepsy in Oppland County, Norway, particularly with respect to age. MATERIALS AND METHODS - Population-based and hospital-based approaches were used to identify individuals with active epilepsy born in 1925, 1940, 1955, 1960 and 1970. Cases with active epilepsy were defined as individuals who had experienced more than one epileptic seizure during the last 5 years and/or were taking antiepileptic drugs. RESULTS - From a population of 11,089 persons, 90 individuals were identified with active epilepsy. The age-distributed prevalence (cases per 1000 individuals born in a specified year) of active epilepsy was 10.2 for those born in 1925, 11.1 for those born in 1940, 4.5 for those born in 1955, 7.5 for those born in 1960 and 9.4 for those born in 1970. Mean epilepsy prevalence was estimated to be 8.2 cases/1000 inhabitants. CONCLUSIONS - An epilepsy prevalence of 8.2 cases/1000 inhabitants is in accordance with the results of similar studies from the western world. However, the results of such studies will vary according to the definition of 'active epilepsy'. By using the narrower International League Against Epilepsy's definition, the prevalence in our study is reduced to 5.3 cases/1000 inhabitants.

Temporal changes in the incidence of epilepsy in Finland: nationwide study

PURPOSE

To examine possible changes over time in the incidence of epilepsy in different age groups.

METHODS

Based on the nationwide full-refundable antiepileptic drug register and population register, incidence of newly diagnosed epilepsy was measured by granted full-refundable antiepileptic drugs for epilepsy.

RESULTS

The incidence was throughout all age groups higher in men than in women. The incidence in the total population had significantly declined in 1986-2002, from 71.6/100,000 to 52.9/100,000. The incidence significantly decreased in children (0.77; 0.71-0.84, p<0.0001) and adults (0.83; 0.77-0.89, p<0.0001) but increased in the elderly (1.18; 1.10-1.26, p<0.0001). The increased incidence in the elderly over the time period was primarily seen in women.

CONCLUSION

The incidence of epilepsy has significantly declined in both children and adults with a concurrent increase in the incidence among the elderly. Further studies are needed to elucidate the precise cause of these temporal changes.

Incidence of epilepsy in a racially diverse, community-dwelling, elderly cohort: results from the Einstein aging study

OBJECTIVE

To determine age-specific incidence and cumulative incidence of epilepsy in a well-defined cohort of elderly people, and to examine how rates of epilepsy are modified by sex, race, stroke, dementia, head injury, and depression.

METHODS

The authors examined data from a reconstructed cohort based on 1919 community-dwelling volunteers, followed as part of a large ongoing prospective aging study.

RESULTS

Age-specific incidence was 10.6 (per 100,000 person-years) between ages 45 and 59, 25.8 between ages 60 and 74, and 101.1 between ages 75 and 89. Cumulative incidence was 0.15% from age 45 to age 60, 0.38% to age 70, 1.01% to age 80, and 1.47% to age 90. In addition, the difference in cumulative incidence among African-American subjects approached statistical significance (57.6/100,000 person-years versus 26.1 in Caucasian, p=0.10), and the difference in incidence among subjects reporting a history of stroke was significantly elevated (p=0.029). Incidence of epilepsy was not statistically elevated among males, those with dementia, or individuals reporting a history of head injury or treatment for depression. Among "healthy" subjects without history of stroke, head injury, or dementia, we observed a cumulative risk of epilepsy with onset after age 60 of only 1.1%.

CONCLUSIONS

The incidence of epilepsy was low in this relatively healthy cohort of elderly people, especially among subjects without known risk factors. In this study we identified African-American race as a risk factor in the elderly for epilepsy independent of stroke.

Epidemiology of idiopathic generalized epilepsies

Idiopathic generalized epilepsies (IGEs) are a relatively new category of disorders defined by strict clinical and electroencephalogram (EEG) features proposed by the International League Against Epilepsy (ILAE) classification of epileptic syndromes. IGEs are usually easy to diagnose when clinical and EEG data are collected, but epilepsy is not synonymous with epileptic syndrome. So far, IGEs are studied in the large group of epilepsies of undetermined or unknown etiology although the genetic origin is now largely accepted. ILAE-proposed criteria are helpful in the clinical and therapeutic management of IGEs, but many epidemiologic studies still confuse the cryptogenic and idiopathic groups. Some syndromes in childhood, which are completely described by strict electroclinical criteria such as the absence epilepsies, juvenile myoclonic epilepsies, are usually included and analyzed in epidemiologic studies; however, other epileptic syndromes observed in infancy, such as benign familial neonatal seizures and benign myoclonic epilepsy in infancy, are quite rare and are usually excluded from epidemiologic surveys because they are difficult to describe completely in electro-clinical terms. Another strong limitation in the study of epidemiology of IGEs is the lack of EEG data, either because EEG is not available or the routine EEG is normal. This is particularly relevant in the inclusion of patients with only tonic-clonic seizures. IGEs encompass several different syndromes, and a few patients shift from one phenotype to another. The overlapping of some syndromes during infancy and adolescence increased the difficulty to individualize strictly the correct syndrome. Many discrepancies can be observed in the distribution of the different syndromes included in the group of IGEs, because the strict criteria for classifying these syndromes proposed by the ILAE are often not respected. With this understanding, the general frequency of IGEs can be assessed at 15-20% of all epilepsies. The frequency and the distribution of incidence and prevalence of the different syndromes are tentatively reported and discussed. When the term idiopathic is used following the restrictive ILAE criteria, the mortality data concerning patients with idiopathic epilepsies do not show an increased standardized mortality ratio.

Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study

BACKGROUND

No population-based incidence studies of epilepsy have studied syndrome classification from the outset. We prospectively studied the incidence of a single unprovoked seizure and epilepsy in the population of Iceland, and applied the syndrome classification endorsed by the International League Against Epilepsy to this population.

METHODS

We used a nationwide surveillance system to prospectively identify all residents of Iceland who presented with a first diagnosis of a single unprovoked seizure or epilepsy between December 1995 and February 1999. All cases were classified by seizure type, cause or risk factors, and epilepsy syndrome.

RESULTS

The mean annual incidence of first unprovoked seizures was 56.8 per 100,000 person-years, 23.5 per 100,000 person-years for single unprovoked seizures, and 33.3 per 100,000 person-years for epilepsy (recurrent unprovoked seizures). Incidence was similar in males and females. Partial seizures occurred in 40% and a putative cause was identified in 33%. Age-specific incidence was highest in the first year of life (130 per 100,000 person-years) and in those 65 years and older (110.5 per 100,000 person-years). Using strict diagnostic criteria for epilepsy syndromes, 58% of cases fell into non-informative categories. Idiopathic epilepsy syndromes were identified in 14% of all cases.

INTERPRETATION

Findings are consistent with incidence studies from developed countries. Although the epilepsy syndrome classification might be useful in tertiary epilepsy centers, it has limited practicality in population studies and for use by general neurologists.

Epidemiological survey of epilepsy in the primary school population in Buenos Aires

BACKGROUND

Most studies carried out in Latin America have shown greater rates of epilepsy and generalized seizures than those observed in developed countries, in spite of lower numbers of patients receiving treatment. To date, studies in Argentina have been insufficient to establish true prevalence.

OBJECTIVE

To determine the prevalence of epilepsy in primary school children in Buenos Aires, together with rates of different seizure types, treatments prescribed, diagnoses made and number of inadequate therapies administered, as well as the relationship between epilepsy and learning difficulties.

DESIGN AND METHOD

A cross-sectional study was carried out on 10% of the entire primary school population of Buenos Aires through randomized, systematic, representative and conglomerate sampling of public and private school students. A total of 26,270 responses were received (83.1% of the population) to a specially designed questionnaire, with 96.4% sensitivity and 41.5% specificity, respectively. Interviews were conducted in all probable epilepsy cases as well as in a random sample of probable negative ones.

RESULTS

Eighty-four children with epilepsy were detected (lifetime prevalence 3.2 per thousand; active prevalence 2.6 per thousand), in whom generalized seizures predominated (57.1%). Ninety-three percent of cases diagnosed were currently under, or had previously received antiepileptic drug (AED) therapy. Almost 1% of the primary school population studied had a prior diagnosis and/or received AED for dysrhythmia or epilepsy. The percentage of grade repeaters in the general population and in children with epilepsy was 8.4 and 26.2%, respectively.

CONCLUSIONS

(1) The prevalence of epilepsy in primary school children in Buenos Aires is similar to that reported for developed countries; (2) a slight prevalence for generalized seizures was observed; (3) 93% of cases received AEDs; (4) misdiagnoses and unnecessary treatments exceeded correct diagnoses and adequate therapy, and (5) disease presence and/or treatment were associated with poorer school performance.

Incidence of epilepsy and predictive factors of epileptic and non-epileptic seizures

PURPOSE

To estimate the incidence of unprovoked seizures (US) and epilepsy in a general population from the southern part of the Netherlands, in relation to age, sex, etiology and seizure type, and to identify predictive factors of the epileptic and non-epileptic seizures.

METHODS

All patients aged > or =14 years with a first seizure or who had undiagnosed seizures before the study period were included. Patients were identified from different sources and were independently evaluated and classified by a team of neurologists. A predictive profile for the occurrence of epileptic and non-epileptic seizures was obtained by stepwise logistic regression analysis.

RESULTS

The overall annual incidence was 55/100,000 and 30/100,000 for US and epilepsy, respectively. The age-specific annual incidence of US and epilepsy increased with age and reached 120/100,000 and 62/100,000 for the > or =65 years of age group, respectively. The incidence of epilepsy and US in males was higher than in females and partial seizures prevailed over generalized seizures (40 versus 9/100,000). In up to 35% of the cases with US or epilepsy, the etiology was mainly cerebrovascular disease and brain tumors. Predictors for epileptic versus non-epileptic seizures of organic origin were an epileptiform EEG pattern (OR=0.06) versus a history of hypertension (OR=2.8) or cardiovascular disease (OR=5.4). Strong predictors for seizures of non-organic origin were female sex (OR=2.2) and head injury (OR=2.4).

CONCLUSIONS

The incidence of US and epilepsy (overall, and age-, sex-, seizure-specific) was similar to those reported by other developed countries. The predictive factors found in this study may assist in the early diagnosis of seizures.

The epidemiology of epilepsy in Europe - a systematic review

Population-based epidemiological studies on epilepsy are available mainly from the UK and the Nordic, Baltic and western Mediterranean countries. No studies were identified from large areas of Europe, especially from the former eastern Europe (except the Baltic countries) and the eastern Mediterranean countries. Based on the prevalence of epilepsy in different studies and accounting for incomplete case identification the estimated number of children and adolescents in Europe with active epilepsy is 0.9 million (prevalence 4.5-5.0 per 1000), 1.9 million in ages 20-64 years (prevalence six per 1000) and 0.6 million in ages 65 years and older (prevalence seven per 1000). Approximately 20-30% of the epilepsy population have more than one seizure per month. Based on the age-specific incidence rates in European studies, the estimated number of new cases per year amongst European children and adolescents is 130,000 (incidence rate 70 per 100,000), 96,000 in adults 20-64 years (incidence rate 30 per 100,000) and 85,000 in the elderly 65 years and older (incidence 100 per 100,000). The proportion of both new and established cases with epilepsy in the young, adults and elderly in individual countries may differ substantially from total European distribution because of differences in age structure.

Study of seizure and epilepsy in Chinese children in Hong Kong: period prevalence and patterns

The Hong Kong Children's Seizure and Epilepsy Registry was set up for all children with a history of seizures or epilepsy followed up in the Epilepsy Clinic of the University of Hong Kong. The aim was to study the pattern of seizures and epileptic disorders in Chinese children. The objective was to study the period prevalence of epilepsy and the pattern of epilepsy in Chinese children. A prospective study of seizure and epilepsy in Chinese children was conducted from 1985 to 1997 in Hong Kong. The population census of 1997 was used to calculate the period prevalence of epilepsy in Chinese children. Altogether, 1103 children aged < 19 years at first assessment with epilepsy were included in the study. The period prevalence rate of epilepsy in 1997 (January to December) is estimated to be 4.5 per 1000 children aged < 19 years. The estimated period prevalence rate of children and adolescents with epilepsy in our children is 4.5 per 1000 children.