Prevalence of childhood epilepsy in Kaunas, Lithuania

A systematic literature review on the global epidemiology of Dravet syndrome and Lennox-Gastaut syndrome: Prevalence, incidence, diagnosis, and mortality

Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare developmental and epileptic encephalopathies associated with seizure and nonseizure symptoms. A comprehensive understanding of how many individuals are affected globally, the diagnostic journey they face, and the extent of mortality associated with these conditions is lacking. Here, we summarize and evaluate published data on the epidemiology of DS and LGS in terms of prevalence, incidence, diagnosis, genetic mutations, and mortality and sudden unexpected death in epilepsy (SUDEP) rates. The full study protocol is registered on PROSPERO (CRD42022316930). After screening 2172 deduplicated records, 91 unique records were included; 67 provided data on DS only, 17 provided data on LGS only, and seven provided data on both. Case definitions varied considerably across studies, particularly for LGS. Incidence and prevalence estimates per 100 000 individuals were generally higher for LGS than for DS (LGS: incidence proportion = 14.5-28, prevalence = 5.8-60.8; DS: incidence proportion = 2.2-6.5, prevalence = 1.2-6.5). Diagnostic delay was frequently reported for LGS, with a wider age range at diagnosis reported than for DS (DS, 1.6-9.2 years; LGS, 2-15 years). Genetic screening data were reported by 63 studies; all screened for SCN1A variants, and only one study specifically focused on individuals with LGS. Individuals with DS had a higher mortality estimate per 1000 person-years than individuals with LGS (DS, 15.84; LGS, 6.12) and a lower median age at death. SUDEP was the most frequently reported cause of death for individuals with DS. Only four studies reported mortality information for LGS, none of which included SUDEP. This systematic review highlights the paucity of epidemiological data available for DS and especially LGS, demonstrating the need for further research and adoption of standardized diagnostic criteria.

The Effect of Epilepsy and Antiepileptic Drugs on Cortical Motor Excitability in Patients With Temporal Lobe Epilepsy

OBJECTIVES

Transcranial magnetic stimulation (TMS) has been used to assess cortical disinhibition/excitation with epilepsy and determine the degree of patients' response to antiepileptic drugs (AEDs). However, the results of studies are variable and conflicting. We assessed cortical motor excitability in adults with temporal lobe epilepsy (TLE).

METHODS

The TMS parameters used for assessment were: resting (RMT) and active (AMT) motor thresholds, cortical silent period (CSP), and central motor conduction time (CMCT).

RESULTS AND CONCLUSIONS

This study included 40 adults (males, 22; females, 18) with TLE with impaired awareness or to bilateral tonic clonic seizures (mean age, 32.50 ± 3.38 years; duration of illness, 6.15 ± 2.02 years) and on treatment with AEDs (valproate, 15; carbamazepine, 15; levetiracetam, 10]. The majority (62.5%) were seizure-free for ≥1 year on AEDs before TMS testing. All had normal brain magnetic resonance imaging except two, who had mesial temporal sclerosis. Comparing the entire patients with controls, patients had significantly bihemispheric higher RMT and AMT particularly over the epileptic hemisphere and shorter CSP and CMCT in the epileptic hemisphere. Shorter CSP and CMCT were observed in patients on valproate or carbamazepine and those who were uncontrolled on medications but not with levetiracetam. Significant correlations were identified between RMT and AMT (P = 0.01) and between CSP and CMCT (P = 0.001). We conclude that chronic TLE had increased cortical disinhibition in the epileptic hemisphere which can spread outside the epileptogenic zone despite the apparent control on AEDs. The TMS studies using CSP and CMCT may help future prediction of pharmacoresistance and, therefore, the need of combined AEDs with multiple mechanisms of action.

Prevalence of childhood and adolescence epilepsy in Upper Egypt (desert areas)

Background

A high prevalence of epilepsy in children is frequently found in developing countries.

Objective

This study aimed to determine the prevalence and clinical pattern of childhood and adolescence epilepsy in Upper Egypt.

Methods

This is a door-to-door study conducted on all inhabitants < 18 years in Al Kharga district and Al Qusier city (36,195 subjects). The study was conducted through two stages; every stage consisted of two phases (screening and diagnostic).

Results

Lifetime prevalence of childhood and adolescence epilepsy (children < 18 years) in Upper Egypt was 9.7/1000, with higher prevalence among children < 12 years (10.8/1000) than adolescents (7.2/1000). The age-specific prevalence was highest in early childhood (12.01/1000) and least at adolescence (7.2/1000). More than half of the patients (59.4%) had idiopathic epilepsy. The most frequent etiology for structural/metabolic epilepsy was perinatal complications, particularly in infancy, followed by central nervous system (CNS) infections, in childhood, and post-traumatic epilepsy in adolescence. Partial seizures were more frequent in infancy, while generalized seizures were more frequent in late childhood and adolescence. Generalized tonic-clonic seizures (GTCS) were the most frequent type of seizures.

Conclusion

Prevalence of childhood and adolescence epilepsy in Upper Egypt was not so much different from other developing countries. Idiopathic epilepsy was more prevalent than structural/metabolic cases. Perinatal complications, CNS infections, and head injury were the most frequent etiologies, and generalized tonic-clonic seizures were the most frequent seizure type.

Electronic supplementary material

The online version of this article (10.1186/s41983-018-0032-0) contains supplementary material, which is available to authorized users.

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.

An estimation of global volume of surgically treatable epilepsy based on a systematic review and meta-analysis of epilepsy

OBJECTIVEEpilepsy is one of the most common neurological disorders, yet its global surgical burden has yet to be characterized. The authors sought to compile the most current epidemiological data to quantify global prevalence and incidence, and estimate global surgically treatable epilepsy. Understanding regional and global epilepsy trends and potential surgical volume is crucial for future policy efforts and resource allocation.METHODSThe authors performed a systematic literature review and meta-analysis to determine the global incidence, lifetime prevalence, and active prevalence of epilepsy; to estimate surgically treatable epilepsy volume; and to evaluate regional trends by WHO regions and World Bank income levels. Data were extracted from all population-based studies with prespecified methodological quality across all countries and demographics, performed between 1990 and 2016 and indexed on PubMed, EMBASE, and Cochrane. The current and annual new case volumes for surgically treatable epilepsy were derived from global epilepsy prevalence and incidence.RESULTSThis systematic review yielded 167 articles, across all WHO regions and income levels. Meta-analysis showed a raw global prevalence of lifetime epilepsy of 1099 per 100,000 people, whereas active epilepsy prevalence is slightly lower at 690 per 100,000 people. Global incidence was found to be 62 cases per 100,000 person-years. The meta-analysis predicted 4.6 million new cases of epilepsy annually worldwide, a prevalence of 51.7 million active epilepsy cases, and 82.3 million people with any lifetime epilepsy diagnosis. Differences across WHO regions and country incomes were significant. The authors estimate that currently 10.1 million patients with epilepsy may be surgical treatment candidates, and 1.4 million new surgically treatable epilepsy cases arise annually. The highest prevalences are found in Africa and Latin America, although the highest incidences are reported in the Middle East and Latin America. These regions are primarily low- and middle-income countries; as expected, the highest disease burden falls disproportionately on regions with the fewest healthcare resources.CONCLUSIONSUnderstanding of the global epilepsy burden has evolved as more regions have been studied. This up-to-date worldwide analysis provides the first estimate of surgical epilepsy volume and an updated comprehensive overview of current epidemiological trends. The disproportionate burden of epilepsy on low- and middle-income countries will require targeted diagnostic and treatment efforts to reduce the global disparities in care and cost. Quantifying global epilepsy provides the first step toward restructuring the allocation of healthcare resources as part of global healthcare system strengthening.

Prevalence of epilepsy in 74,949 school children in Khartoum State, Sudan

BACKGROUND

Data on childhood epilepsy in Sudan are scarce and the only published study on its prevalence was published in 1983. This study aimed to determine the current prevalence of epilepsy in school children in Khartoum State.

METHODS

This is an analytical population-based, cross-sectional study conducted in Khartoum State, Sudan. The study included students in the basic (primary) schools aged 6-14 years. Simple random sampling was used to draw a cluster of four of the seven localities comprising Khartoum State. The sample frame consisted of 1609 public schools (808,624 pupils) and 787 private schools (194,613 pupils), a total of 2396 schools (1,003,237 pupils). A sample size of 75 940 pupils was estimated and 250 schools were drawn from a sample frame of 2396 schools using a stratified random sampling technique. Consent was obtained from the headmaster/head teacher of the selected schools who arranged a meeting with the tutor/teacher responsible for each class. The study team asked whether any of the pupils was ever noticed or known to have had any kind of seizures, and a confidential letter was sent to the parents of each identified pupil. The letter included an explanation of the aims of the study, information on the research group and the kind of help the research group could offer; contact numbers and email addresses were made available if they wished to participate in this study. Those who consented to participate were then given an appointment at the Epilepsy Outpatient Department, Gaafar Ibnauf Children's Hospital, Khartoum where they were evaluated by the paediatric neurologist.

RESULTS

Altogether, 74,949 pupils were enrolled for the study, 398 of whom were identified initially as having seizures and 332 of whom (83.4%) were identified by a paediatric neurologist. Of the 332, 303 (91.3%) proved to have epileptic seizures, 250 (82.5%) were known to have epilepsy, and 53 (17.5%) were newly diagnosed during the survey. The male to female ratio was 1.5:1. The total prevalence of epilepsy in Khartoum State was estimated to be 4/1000. The highest prevalence was in Jabal Awliya Locality (4.87/1000) and the lowest was in Khartoum Locality (3.35/1000). Twenty-nine (8.7%) patients proved to have non-epileptic seizures. The majority (15, 51.6%) had psychogenic non-epileptic seizures, and four (13.6%) had syncope. The majority (171, 56.43%) of patients had generalised epilepsy, 109 (35.97%) had focal epilepsy, and 23 (7.6%) had unclassified epilepsy.

CONCLUSION

The prevalence of epilepsy in school children in Khartoum State (4/1000) is higher than that reported previously from Khartoum Province in 1983 (0.9/1000).

A ten-year follow-up cohort study of childhood epilepsy: Changes in epilepsy diagnosis with age

OBJECTIVE

To elucidate all of the characteristics of childhood epilepsy, we performed a long-term follow-up study on the patients who visited Okayama University Hospital.

SUBJECTS AND METHODS

We retrospectively investigated the patients who were involved in the previous epidemiological study and visited Okayama University Hospital for a period of 10years after December 31, 1999.

RESULTS

Overall, there were 350 patients' medical records that were evaluated, and 258 patients with complete clinical information available for a 10-year period were enrolled. Ten patients died and the remaining 82 were lost to follow-up. Of 258 patients with complete information, 153 (59.3%) were seizure-free for at least 5years. One hundred thirty (50.4%) had intellectual disabilities and 77 (29.8%) had motor disabilities, including 75 (29.1%) with both disabilities on December 31, 2009. Thirty-four patients of 350 (9.7%) changed the epilepsy classification during follow-up. With regard to ten patients who died, nine of them had symptomatic epilepsy, particularly those with severe underlying disorders with an onset during the first year of life.

CONCLUSION

Clinical status considerably changed during the decade-long follow-up period in childhood epilepsy. Changes in the epilepsy diagnosis are especially important and should be taken into account in the long-term care of children with epilepsy.

The epidemiology of epilepsy in children: a report from a Turkish pediatric neurology clinic

This retrospective cohort study aims to assess the distribution of seizure types and epileptic syndromes in children with epilepsy who were followed up in a tertiary outpatient pediatric neurology clinic between January 2004 and December 2009. The findings of 533 children aged between 2 months and 16 years were evaluated. The International League Against Epilepsy criteria (of 1981 and 1989) were used for diagnosis and classification. The rate of partial seizures (56.5%) was higher than that of generalized seizures (43.5%). Partial seizures were more common during late childhood (P < .001). Localization-related epilepsies (53.3%) were more frequent than generalized epilepsies (37.1%). Generalized epilepsies were more frequent during the first year of life, whereas localization-related epilepsies were more common at later ages (P < .001). The majority had a symptomatic etiology (47.1%). The increased frequency of symptomatic etiologies attributed to perinatal insults suggests that intractable epilepsies during childhood represent an important health issue for developing countries.

Prevalence and risk factors of epilepsy among school children in eastern Turkey

Epilepsy is a serious chronic brain disorder of childhood. We performed a cross-sectional prevalence study, determined the prevalence of childhood epilepsy, and identified the significance of certain risk factors for epilepsy among 1625 primary-school students aged 6-14 years, living in the center of Kars province. A questionnaire was prepared according to the definitions and principles of the Commission on Epidemiology and Prognosis, International League Against Epilepsy. Twenty-two children were diagnosed as epileptic. The point prevalence of active epilepsy in males was 4.9/1000, and in females 12.4/1000, representing a total of 8.6/1000. The cumulative prevalence in males was 11.0/1000, and 16.1/1000 in females, representing a total of 13.5/1000. Febrile convulsions, family history of epilepsy, serious maternal illness during pregnancy, a history of head trauma, antenatal/postnatal problems, and a history of neonatal jaundice were statistically significantly related to the development of epilepsy.

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.

Prevalence of epilepsy in children from a Brazilian area of high deprivation

This study assessed the prevalence rate of epilepsy and its causes in children and adolescents in one area of high deprivation in São Paulo, São Paulo, in Southeast Brazil. Between July 2005 and June 2006, 4947 families from a population of 22,013 inhabitants (including 10,405 children and adolescents between the ages of 0 and 16 years) living in the shantytown of Paraisópolis, were interviewed. In the first phase, a validated questionnaire was administered, to identify the occurrence of seizures. In the second phase, clinical history, neurologic examination, electroencephalography, and structural neuroimaging were performed. The diagnosis of epilepsy, including etiology, seizure types, and epileptic syndrome classification, was according to criteria of the International League Against Epilepsy. The screening phase identified 353 presumptive cases. In the second phase, 101 of these cases (33.8%) received the diagnosis of epilepsy. Crude prevalence of epilepsy was 9.7/1000 and prevalence of active epilepsy was 8.7/1000. Partial seizures were the most frequent seizure type (62/101). Symptomatic focal epilepsy was the most common form, and hypoxic-ischemic encephalopathy the most common etiology, reflecting the socioeconomic conditions of this specific population. Adequate public policies regarding perinatal assistance could help reduce the prevalence of epilepsy.

Incidence of febrile seizures in Finland: prospective population-based study

The objective was to study the incidence of febrile seizures prospectively determined through age 4 years. A standardized randomized cluster sample of nulliparous pregnant women from a geographically defined area were prospectively followed from the beginning of pregnancy through the child's age 4. Data on children eligible for the study (n = 1287), including febrile seizures, sociodemographic data, developmental milestones, and chronic diseases, were prospectively collected from families and health care staff. Data were available for 1033 children. Through age 4, the average annual incidence of febrile seizures was 14 per 1000 person-years (15 for girls and 13.5 for boys). The incidence rate through age 4 was 6.9% (7.3% for girls and 6.5% for boys). The incidence rate of febrile seizures in Finnish children is comparable to that reported previously. The higher figure, based on prospective rather than retrospective data, may give a more accurate picture of the clinical importance of febrile seizures.

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.

Prevalence of epilepsy in Croatia: a population-based survey

OBJECTIVES

To investigate the prevalence of active epilepsy in Croatia.

MATERIAL AND METHODS

Patient data collected by means of questionnaires completed by primary healthcare physicians; epilepsy was previously confirmed in the patients by neurologists or neuropaediatricans.

RESULTS

One hundred and twenty-seven of 180 (71%) physicians provided the requested information. The total sample was 212 069 people and of these 1022 had active epilepsy. Prevalence rates (per 1000) for the following age-groups were: age 0-7: 3.5; age 8-18: 6.4; age 19-45: 5.0; age 46-65: 4.7; age >65: 4.4. The age-adjusted prevalence rates for the standard populations were 4.9/1000 (European population) and 5.0/1000 (WHO world population). Fifty-one physicians (29%) stated only the number of patients they considered as having active epilepsy but without the requested details. If their patients were also included, the estimated crude prevalence rate would be 5.5/1000.

CONCLUSIONS

It is likely that the prevalence of active epilepsy in Croatia is between 4.8 and 5.5/1000; this is in keeping with findings from other European countries.

Prevalence of seizures and associated factors in children under five living in a deprived municipality of southern Brazil

OBJECTIVE: To determine the frequency and distribution of seizure in children under five, living in a deprived community. METHOD: This was a cross-sectional study, conducted in a probabilistic sample of 487 children aged 5 or less, resident in the rural and urban areas of São José do Norte, a poor municipality in southern Brazil, during the period 1998-99. Children were identified as having this disorder after the application of the three subsequent instruments, the screening questionnaire for epileptic seizures (SQES), the neurological diagnostic interview for epilepsy (NDIE) and the EEG. Statistical analysis included a multivariate analysis using Poisson regression. Prevalence ratios (PR) and 95% confidence intervals (CI) were calculated. RESULTS: Diagnosis of epileptic seizures was confirmed in 22 children. Prevalence of seizure was 45.2/1000 (CI 2.9-6.8). Absence of tap water (PR 2.86; IC 1.15-7.10), and precarious housing (PR 2.50; CI 1.01-6.18) were significantly associated with the outcome. CONCLUSION: Prevalence of seizure in this deprived population is extremely high and related to socio-economic conditions.

A population based study of epilepsy in children from a Swedish county

BACKGROUND

Epidemiological studies of childhood epilepsy are of importance to compare incidence and prevalence rates, age distribution, inheritance, seizure types, epilepsy syndromes and treatment strategies.

AIM

To perform an epidemiological study on children with epilepsy in a Swedish county using current ILAE classifications and a recent proposal.

METHODS

A population-based study was performed using the hospital data register to select children aged 1 month to 16 years with the diagnosis 'convulsions' or 'epilepsy' recognized between January 1996 and December 2000. Only patients with active epilepsy were included.

RESULTS

Two hundred and five children met the study criteria on the prevalence day 31st December, 2000. The total prevalence rate was 3.4/1,000 with a peak prevalence in the age group 8-11 years. The incidence year 2000 was 40/100,000. Additional neuroimpairments were registered in 47.3%. A majority of the patients, 54.0%, had focal or focal plus secondarily generalized seizures. A named syndrome could be diagnosed in 49.4%. The most common syndrome was rolandic epilepsy occurring in 17.0%. Childhood absence epilepsy occurred in 5.9%. Different disorders associated with epilepsy were found in 31.7%. The most common associated phenomenon was malformation of cortical development. Antiepileptic drug treatment was used in 81.0%, the most common first choice being valproate.

CONCLUSIONS

The prevalence and incidence rates in this strictly delineated study are lower than those found in other epidemiological studies. Together with many divergences between reported studies concerning frequencies of different items, the results apparently depend on design, e.g. differences in age groups included, inclusion criteria used, and general methodology.

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.

Prevalence and Characteristics of Epilepsy in the Aeolian Islands

PURPOSE

To estimate the prevalence and define the clinical characteristics of epileptic disorders in the 13,431 residents of the Sicilian Aeolian archipelago, on June 1, 1999.

METHODS

All established or suspected cases were identified by the neurologists of our working group from available medical information sources. Possible epilepsy cases were then evaluated by the epileptologists by using a standardized questionnaire. The patients were further reviewed by the whole research team to confirm the clinical diagnosis. For a more detailed syndromic definition, some patients underwent EEG or neuroradiologic investigations or both.

RESULTS

The crude point prevalence rate of active epilepsy was 3.13 (95% confidence interval, 2.2-4.2). The prevalence rate age-adjusted to the 2001 Italian population was 3.01. Females had a slightly higher prevalence rate than did males. The highest age-specific prevalence was found in patients aged 5 to 14 years (5.05) and in those aged 65 to 74 years (5.41). Partial seizures with or without secondary generalization were more common (61.7%) than were generalized seizures. Eighty-three percent of cases had symptomatic or cryptogenic localization-related epilepsies, and 8.5% had idiopathic (generalized or partial) epilepsies. Epilepsy was unclassified in 8.5% of cases.

CONCLUSIONS

The prevalence of active epilepsy in the Aeolian islands is lower than that in other developed areas, including northern Italy, but is similar to that in Sicily. Partial seizures were the most common type, and localization-related symptomatic epilepsies were the largest syndromic category.

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.

Cranial computed tomography in partial motor seizures

OBJECTIVE

To identify the pattern of intracranial structural lesions in developmentally normal children with partial motor seizures by computed tomography and to monitor the behavior of single ring enhancing lesion (SREL) after a period of time with or without treatment.

METHODS

Consecutive developmentally normal children between one year and twelve years with partial motor seizures in a tertiary care referral Hospital. After clinical examination and appropriate investigation for tuberculosis and cysticercosis, CT scan was performed. In addition to anticonvulsants, children received antituberculous or anticysticercal therapy if indicated. Repeat CT was performed on children with SREL after 6 months.

RESULTS

Computed tomography was abnormal in 102 (68%) children. Majority of the children (75) had SREL. The lesions were located in decreasing order of frequency in the parietal lobe (65), frontal lobe (7), occipital lobe (1), temporal lobe (1) and cerebellum (1). Repeat CT scan was performed on 50 of the 75 children with SREL. Among these, in 41 children who were only on antiepileptic therapy, the SREL had decreased in size in thirty-two whereas in the rest (9), there was no change in the size.

CONCLUSION

Awareness of the existence of disappearing SREL lesions is essential to avoid unnecessary treatment with antituberculous or anticysticercal therapy and provides ample justification in treating with anticonvulsant drugs only.

Prevalence of epilepsy in Turkish children between the ages of 0 and 16 years

The aim of this cross-sectional study was to determine the prevalence of epilepsy in Turkey among children between the ages of 0 and 16 years. The study population consisted of 24,773,569 children living in Turkey. Because the prevalence of childhood epilepsy is reported to be 0.001 to 1% in the literature, the sample size was determined as 48,260, with 0.05 error type I and 0.10 error type 2 (power 0.90), and the effect size was 2. With the cluster sampling method, samples were selected from cities, towns, districts, and villages, and 46,813 (97%) children were reached. The study questionnaire contained sections with individual informational questions and questions for the selection of suspected epilepsy cases and physical examination results. The epilepsy classification was designed according to the classification of the International League Against Epilepsy (ILAE). The prevalence of epilepsy was determined as 0.8%; 55.2% of the subjects with epilepsy were grouped as generalized, 39% as partial, and 5.8% as unidentified. Age, place of residence, route of delivery, place of delivery, and social and economic status had no statistically significant effect on the development of epilepsy. Male gender, preterm, and post-term delivery increased the risk of developing epilepsy. Early diagnosis and treatment of epilepsy, as well as the education of health workers and families, are very important.

The prevalence of epilepsy amongst school children in Izmir, Turkey

OBJECTIVE

The aim of this study was to assess the prevalence of epilepsy among school children between the ages of 7-17 in Izmir province, in Turkey.

METHODS

A cross sectional study was conducted. Sample size is calculated as 4654, from the target population of 420054 students. A stratified random sampling technique was used to select the schools located in Izmir Metropolitan area. For the 130 (2.8%) students whose families gave a positive 'epilepsy history' a telephone interview was conducted in order to verify the diagnosis and to evaluate a etiological factors.

RESULTS

Response rate was 90.5% (4216 students). Out of the 130 students who had a positive epilepsy history, 47 (36.2%) were accepted as epilepsy 'cases'. The crude prevalence rates for females, males and the total study population were found respectively to the 11.3, 11.1 and 11.2 per thousand. Prevalence of active epilepsy rates for females, males and total study population were found respectively to be 4.5, 7.0 and 5.6 per thousand.

CONCLUSION

The prevalence of epilepsy is higher in school-age children in Izmir province compared to that in developed countries.

Epidemiology of childhood epilepsy in a cohort of 309 Chinese children

The present study describes the characteristics of epilepsy in a cohort of Chinese epileptic children. All children with active epilepsy who were under 15 years of age and residing in the catchment area of Tuen Mun Hospital, Hong Kong were monitored. Etiology, seizure types, and epilepsy syndromes were classified according to the recent guidelines of the International League Against Epilepsy. A total of 309 children were recruited into the study. The etiology of epilepsy was idiopathic in 42% of the children, cryptogenic in 16.8%, and remote symptomatic in 40.8%. Perinatal factors were the most frequently found cause of epilepsy. Seizure types were partial in 48.5% of the children and generalized in 46.9%. Epilepsy syndromes could be classified in all but seven patients, with 48.2% localization related and 49.5% generalized. Generalized seizures were more prevalent in children less than 5 years of age. Additional neuroimpairments affected 36% of our epileptic children. Sixty-nine percent of patients were seizure free for more than 1 year. The authors conclude that the International League Against Epilepsy can be applied successfully to a population-based cohort of Chinese epileptic children. A larger, longitudinal epidemiologic study is needed to answer questions concerning the true prevalence, incidence, types, and etiologies in the Chinese population.

Prevalence, classification, and severity of epilepsy in children in western Norway

PURPOSE

To determine prevalence of active epilepsy in school children in a defined area and assess the usefulness of International League Against Epilepsy classification of seizures and epileptic syndromes, with special emphasis on frequency, additional handicaps, and therapeutic problems of severe cases.

METHODS

The latest International League Against Epilepsy International Classification of Epileptic Seizures (ICES, 1981) and Epilepsies and Epileptic Syndromes (ICE, 1989) were used for determination of prevalence rates, seizure types, epilepsies and epileptic syndromes, and additional neurological deficits in all 6-to 12-year-old children with epilepsy in a Norwegian county. Children had neuropediatric and EEG examination, intelligence evaluation, and, when necessary, additional investigations.

RESULTS

Prevalence of active epilepsy on January 1, 1995, was 5.1 per 1,000. Main seizure type and epilepsy syndrome could be classified in 98% and 90% of patients, respectively. Seizure types/epileptic syndromes were more often partial/localization related than generalized. Among generalized epilepsies, idiopathic forms were more frequent in girls, and cryptogenic and symptomatic forms more frequent in boys. Epileptogenic EEG activity was most often generalized or localized to one or two areas of the brain and was never found in 14% of patients. Symptomatic etiology was found in 46% of all children and in 81% of therapy-resistant cases, respectively. Over the years, 11% of children had never used antiepileptic drugs (AED), 62% had tried one or two AEDs, and 26% had tried from three to 15 AEDs. Twenty-five percent of children were without present AED treatment. Complementary/alternative medicine had been tried by 12% of children.

CONCLUSIONS

Although most epilepsies could be classified, the number of cases in non-specific categories was relatively high. Symptomatic etiology was frequent, especially in therapy-resistant cases. Multidisciplinary therapeutic and habilitation approaches are often needed in childhood epilepsy.

Prevalence of childhood epilepsy in Estonia

PURPOSE

To establish the prevalence rate (PR) and main characteristics of childhood epilepsy in Estonia.

METHODS

We performed a population-based case ascertainment of all the possible sources of medical care in seven counties of Estonia from January 1995 to December 1997. Only cases of patients from 1 month to 19 years of age with active epilepsy (i.e., at least one seizure during the last 5 years, regardless of treatment) were included. All patients were examined by a pediatric neurologist.

RESULTS

Five hundred sixty cases met the study criteria on the prevalence day, December 31, 1997. The total PR was 3.6 per 1,000 population (boy/girl ratio, 1.2:1.0). The PR was the highest-4.3 per 1,000-in the 5-to-9-year-old age group. The prevalence declined markedly in children age 14 years and on. The correlation between age and PR was negative (-0.542, p < 0.0001) by regression analyses. The most frequent seizure types in the total group were primarily generalized seizures-PR 2. 1/1,000 [rate ratio (RR) 1.4, 95% confidence interval (CI) 1.2, 1.6]. The predominance of generalized seizures was significant in those younger than 10 years. In 14.8% of cases, there was a history of epilepsy among first- and second-degree relatives. Benign rolandic epilepsy-PR 0.2/1,000-was the most frequent among idiopathic syndromes, and Lennox-Gastaut syndrome-PR 0.08/1,000-was the most frequent among cryptogenic ones. Perinatal factors-PR 0.8/1,000 were the most frequently found cause of epilepsy. In 304 cases (54.2%), additional medical problems existed.

CONCLUSIONS

The prevalence of childhood epilepsy was comparable with that found in developed countries. Generalized seizures predominated, and the main cause was perinatal factors.