Prevalence and pattern of epilepsy (Lath/Mirgi/Laran) in rural Kashmir, India

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.

Prevalence and pattern of epilepsy in India

PURPOSE

To estimate the prevalence of epilepsy in India by meta-analysis of previously published and unpublished studies and to determine patterns of epilepsy by using community-based studies.

METHODS

We attempted to identify as many previously published and unpublished studies as possible on the prevalence of epilepsy in India. The studies were assessed with regard to methods and definitions. The prevalence rates for rural and urban populations and for men and women were calculated with a 95% confidence interval (CI). The studies that provided details on age structure, age-specific rates, and patterns of epilepsy were chosen for meta-analysis. Both crude values and age-standardized prevalence rates were calculated after accounting for heterogeneity.

RESULTS

Twenty studies were found involving a sample population of 598,910, among whom 3,207 had epilepsy. This resulted in a crude prevalence of 5.35/1,000. After a correction for heterogeneity due to interstudy variation, the overall prevalence per 1,000 (and its 95% CI) was 5.33 (4.25-6.41); with urban areas at 5.11 (3.49-6.73); rural areas, 5.47 (4.04-6.9); men, 5.88 (3.89-7.87); and women 5.51 (3.49-7.53). After correction for the variability in estimates of heterogeneity, age-standardized rates (from five studies) revealed that the prevalence rates per 1,000 (and the 95% CI), were as follows: overall, 5.59 (4.15-7.03); men, 6.05 (3.79-8.31); women, 5.18 (3.04-7.32); urban, 6.34 (3.43-9.25); rural, 4.94 (3.12-6.76). Urban men and women had a higher prevalence of epilepsy compared with rural ones, however the difference was not statistically significant. Age-specific prevalence rates were higher in the younger age group, with the onset of epilepsy reported mostly in the first three decades of the sample population's lives. The treatment gap (i.e., the percentage of those with epilepsy who were receiving no or inadequate treatment) was more than 70% in the rural areas.

CONCLUSIONS

Based on the total projected population of India in the year 2001, the estimated number of people with epilepsy would be 5.5 million. Based on a single study on the incidence of epilepsy, the number of new cases of epilepsy each year would be close to half a million. Because rural population constitutes 74% of the Indian population, the number of people with epilepsy in rural areas will be approximately 4.1 million, three fourths of whom will not be getting any specific treatment as per the present standard.

Prevalence of epilepsy in Silivri, a rural area of Turkey

PURPOSE

To learn the prevalence of epilepsy in Silivri, a western town of Turkey, a randomized door-to-door survey was conducted using a standard questionnaire. The method of the study was adopted from the suggestions of the World Health Organization (WHO) for prevalence studies in developing countries, and the criteria were derived from Guidelines for Epidemiologic Studies on Epilepsy proposed by the Commission on Epidemiology and Prognosis, the International League Against Epilepsy (ILAE) 1993.

METHODS

From June 1 to October 1, 1994, 4,803 people out of a total population of 70,394 were surveyed. The questionnaire, which was administered by practitioners and intern doctors, consisted of 15 questions, with a sensitivity of 99.9% and a specificity of 76%. After the survey, neurologists examined all of the 415 people suspected of having epilepsy and classified the seizures of the active cases.

RESULTS

Of the 415 suspected cases, 49 people (24 women, 25 men) were determined as having epilepsy on the assessment day of October 1, 1994. The crude point prevalence of active epilepsy was 10.2 of 1,000 for the region. The prevalence of active epilepsy among women was 10.01 of 1,000 and among men was 10.39 of 1,000. Of the 49 cases, 40.8% had generalized seizures, 53.1% had partial onset seizures, and 6.1% could not be classified. Only 7.7% of the cases with partial onset seizures were defined as probable symptomatic cases.

CONCLUSIONS

Onset of the disease peaked at the first decade of life. On the assessment day, 44.9% of those with epilepsy were receiving treatment, and 65.1% had visited religious figures at the onset or during the course of the disease, a figure that reveals the high prevalence of mystical beliefs about the disease in the study area.

A case control study and one year follow-up of registered epilepsy cases in a resettlement colony of North India, a developing tropical country

A population-based case control study and monthly follow-up of 121 registered epilepsy cases was conducted during 1995-1997 in a resettlement colony of Chandigarh, India. History of various tentative risk factors, e.g. trauma, febrile seizures, family history of seizures, alcohol intake and other possible causes was elicited. An age- and sex-matched control was selected from the neighbouring families for each case. A discordant pair analysis was done for matched case/controls. History of head injury, febrile seizures and developmental delay was observed exclusively in cases (none present in controls). Odds for epilepsy were higher among people who had positive family history (O.R.= 2.1, chi2 = 5.5, C.I. = 1.1-4.3). All cases were followed up and interviewed for history of seizures and drug intake. Fourteen cases could not be followed up completely. Ninety-four (88%) of the remaining 107 cases did not have any seizures during the follow-up. Of them, 70 (75%) patients were not on medication, 13 patients were on phenytoin and 11 patients received phenobarbitone. Thirteen cases reported seizures during the follow-up. Four patients out of the latter had mental retardation and were not on medication. Cumulative incidence of epilepsy was estimated to be 0.6/1000 person-year exposure.

The Yelandur study: a community-based approach to epilepsy in rural South India--epidemiological aspects

Data on the epidemiology of epilepsy in a rural community in a developing country would be of value in planning a decentralized management of this malady in its early stages commensurate with available local resources. A detailed screening instrument covering various seizure types was used by trained paramedical workers in a door-to-door survey of a population of 64,963 in rural South India. The prevalence period was from 1 April 1990 to 31 March 1991. The crude prevalence rate per 1000 for active epilepsy was 4.38 for males, 3.40 for females and 3.91 for both. The minimum and maximum prevalence rates, the latter computed from a validation sample, were 3.91 and 4.63 for active epilepsy; 0.28 and 0.77 for inactive epilepsy and 4.19 and 5.41 for life-time prevalence. In addition, corresponding figures for hot-water epilepsy, a type of reflex epilepsy peculiar to this area, were 2.49 and 2.99 for active phase; 0.35 and 0.85 for inactive phase and 2.85 and 3.83 for life-time prevalence. The incidence rate for epilepsy was 49.3 per 100,000, the same as in developed countries. These data do not support the concept that the prevalence of epilepsy in developing countries is twice that in the developed world. However, the role of local/regional variations should be borne in mind before extrapolating the figures to an entire country.

Etiological spectrum of symptomatic localization related epilepsies: a study from South India

Putative etiology was studied in 991 patients with symptomatic localization-related epilepsies seen in a university hospital in South India. They formed 39% of patients with various types of epilepsies and epileptic syndromes seen during the study period. Seizure occurred in close temporal association with an acute central nervous system (CNS) insult in 53% of patients. Infections of CNS including single CT enhancing lesion (SCTEL) accounted for 77% of patients with acute symptomatic epilepsy. Cerebrovascular diseases were the risk factors in 48% of patients with remote symptomatic epilepsy. Neurocysticercosis, SCTEL and small single cerebral calcific CT lesion (SSCCCTL) together accounted for 40% of etiological factors and neurotuberculosis for 10%. Infections of the central nervous system and SCTEL together were the putative risk factors in 52% of patients aged < or =40 years. Cerebrovascular diseases were the etiological factors in 64% of patients aged >40 years. Neurological handicaps from birth manifested by mental retardation and/or cerebral palsy was the feature in 21% of children. The type of seizure was either simple partial or complex partial with or without secondary generalization in 76% of patients. The remaining patients presented with either generalized tonic clonic seizures or unlocalized seizures. Localization to a single site of seizure origin proposed by the International League Against Epilepsy (ILAE) was possible in only 67.5% of patients. The most readily identifiable was motor cortex. In patients with unlocalized or generalized seizures the type of pathology was diffuse in 17% of patients and in 48.5% of patients, the lesion was located in the frontal brontoparietal lobe.

The prevalence and associated factors of epilepsy in children in Calicut District, Kerala, India

To determine the prevalence of epilepsy and its association with indices of malnutrition, infection and perinatal complications in children in Calicut District, Kerala, India, a door-to-door two-stage survey was conducted in two local government districts. Among the random sample of 1172 children aged 8-12 y, 26 conformed to the definition of epilepsy giving a 5-y period prevalence of 22.2/1000. A history of perinatal complications, low BMI and recent physical symptoms were independently associated with active epilepsy. The results suggest epilepsy is highly prevalent in this population of children and that further research is needed into its cause.

Epilepsy in developing countries

On June 6th and 7th, 1996, an international workshop on specific aspects of epilepsy in the developing world was organized in Geneva by the chairman of the ILAE Commission of Epilepsy in Developing Countries, P. Jallon, involving members of the ILAE, the World Health Organization (WHO), and a network of people who work with epilepsy patients in developing countries. Those taking part included all the members of the ILAE Commission on Epilepsy in Developing Countries, the chairmen of the ILAE Commissions on Tropical Diseases, Epidemiology, Education, Economics, and Drugs, as well as the president, treasurer, and past president of the ILAE; and the president of the IBE, Hanneke de Boer. There were representatives from Eastern European countries (Russia, Slovenia, Turkey), South America (Brazil, Colombia, Uruguay, Ecuador, Venezuela), Africa (Ethiopia, Senegal, South Africa, Togo, Tunisia), and Asia (India, Indonesia, Pakistan, Sri Lanka, The Philippines and China). Representatives from WHO joined the meeting on the last day (Drs. L. Prilipko, A. Janca, and C. L. Bolis). Three major topics were considered--epidemiology, medical assessment, and therapeutic aspects as well as some economic and social aspects of the disease. A second mission of this meeting was to work with WHO representatives to develop a program for action to care for people with epilepsy in these countries.

Prevalence of childhood epilepsy in Kaunas, Lithuania

The prevalence of epilepsy in children aged 0-15 years of Kaunas city, Lithuania, was evaluated on 1 January 1995. Multiple sources for case identification were used, i.e. medical records at the university hospital, regional outpatient clinics and consultation centres, institutions, schools and kindergartens for the handicapped. Active epilepsy was defined as two or more unprovoked epileptic seizures with at least one seizure occurring within the previous 5 years, regardless of the antiepileptic drug treatment. Prevalence was found to be 4.25 (3.42, if age-standardized) in 1000. The highest rate was found in the 10-14 years age group. The male/female ratio was 1.29. No possible causes could be determined in 60.3% of cases. Congenital causes were diagnosed in 18.8% of cases, perinatal causes in 15.3%, traumatic causes in 2.6% and neuroinfectious causes in 2.4%. Classification of epilepsies and epileptic syndromes [Commission on Classification and Prognosis of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30:389-399] revealed that 50% of cases were localization-related epilepsies, 29.9% were generalized epilepsies, 15.9% were undetermined whether partial or generalized and 4.2% were unclassifiable. Rates for idiopathic, symptomatic and cryptogenic cases are presented.

Comparative epidemiology of epilepsy in Pakistan and Turkey: population-based studies using identical protocols

PURPOSE

To determine comparative prevalence rates, demographics, phenomenology, seizure classification, presumptive etiology, treatment status, and selected socioanthropological aspects of epilepsy in Pakistan and Turkey.

METHODS

A population-based, cross-cultural comparative study of epilepsy was designed with identical protocols to be performed simultaneously in Pakistan and Turkey. The essential feature of the design was an unselected population, with reference to their previous medical contact, and use of standardized International Community-Based Epilepsy Research Group (ICBERG) protocols to assess cross-cultural differences.

RESULTS

In all, 24,130 persons in Pakistan and 11,497 persons in Turkey (both urban and rural, of all ages and both sexes) were studied. The crude prevalence rate of epilepsy was 9.98 in 1,000 in Pakistan and 7.0 in 1,000 in Turkey (14.8 in 1,000 in rural and 7.4 in 1,000 in urban areas of Pakistan; 8.8 in 1,000 in rural and 4.5 in 1,000 in urban areas of Turkey). In both countries, epilepsy was twice as prevalent in rural areas than in urban areas. Mean age of onset of epilepsy was 13.3 years in Pakistan and 12.9 years in Turkey. Overall frequency of seizure types was similar in both countries, with no urban/rural differences. The frequency distribution in Pakistan and Turkey, respectively, was as follows; generalized tonic-clonic, 80.5 and 65.4%; simple partial, 5 and 7.4%; complex partial, 5 and 12.3%; generalized absence, 0.8 and 4.9%; tonic and atonic, 5.8 and 3.7% each; and myoclonic, 5.8 and 1.2%. A putative cause for the epilepsy could be attributed in 38.4% of cases in Pakistan and 35.7% of cases in Turkey. Only 3% of patients in Pakistan, but 71% of patients in Turkey, believed that their illness was due to supernatural causes. The treatment status was very poor. In Pakistan, 27.5% of people with epilepsy in urban areas and 1.9% of people with epilepsy in rural areas were receiving antiepileptic drugs (AEDs) at the time of the survey. In, Turkey 30% of patients were receiving AEDs (marginally higher in rural areas).

CONCLUSIONS

The prevalence of epilepsy is slightly higher in Pakistan than in Turkey; some marginal differences in age and sex distribution, are not statistically significant. The results are comparable to those in Ecuador, where the same epidemiologic protocol was used.

Epilepsy and teachers: a survey

Teachers in five primary schools were surveyed for their knowledge and attitudes about epilepsy. An analysis of 113 teacher responses revealed knowledge deficits, especially regarding the prevalence of epilepsy, the future of children with the disorder and E.E.G. as an aid to diagnosis. Misconceptions regarding first aid were also common. More than two-thirds of the teachers believed that children with epilepsy have academic problems more often, although about half of the respondents were in favour of normal schools for such children. Most respondents recommended a teacher's career for these children in future but considered that of a bus driver, as unsuitable. Few teachers had attended any educational programme on epilepsy. Only about one-fifth of the teachers were confident in dealing with an epiletic child. Communication about epilepsy among the teachers, parents and doctors was virtually non-existent.

Management and referral patterns of epilepsy in india

Evaluation of management and referral pattern is very important in the organization of medical services for epilepsy. In order to study the management and referral pattern of epilepsy, a structured questionnaire was administered to 100 epilepsy patients attending a referral hospital in Kerala State, India. Of these, 61.4% of them were living in villages; 65% had a monthly income less than Rs. 1000. Seventy-five percent of the patients had generalized seizures. The mean delay in diagnosis was more for those from villages (13.5 months) as compared to those from urban areas (6.4 months) and for women (11.7 months) as compared to men (7.8 months). Previous consultation before referral to this Institute included general practitioners (61%), specialists (50%) and neurologist or neurosurgeon (27%). Eighty-eight patients have had EEG and 51 patients have had CT Scans. Thirty-nine per cent of patients required hospitalization for control of seizures that was significantly (P = 0.036) higher among those living in an urban area. Seventy-five per cent of patients were collecting drugs from private pharmacies. No patient was collecting antiepileptic drugs from government institutions even though such a facility was available within 5 km of their residence. This study has revealed that the organization and delivery of neurological services for epilepsy leaves much to be desired.

Evaluation of epilepsy management in a developing country: a prospective study of 407 patients

407 patients (248 men, 159 women) of epilepsy attending the neurology clinic were evaluated to find out the profile of epilepsy, cost-effectiveness of various investigations, therapeutic regimens and efficacy of referring physicians in a developing country. At the time of onset of seizures 67.2% of patients were in the second and third decade. Generalised tonic clonic seizures were the commonest seizure type seen. Specific aetiology was established in 20.8% cases only. Neurocysticercosis was the commonest cause observed. The main source of referral (50.1%) was general practitioners. Referral diagnosis was incomplete in 52.8% of the cases. Investigations did not alter the diagnosis in 62.5% cases. The EEG was useful in the management of 15.1% cases of epilepsy. The skull x-ray and chest x-ray were abnormal in 1.7% and 2% cases respectively. CT scan revealed abnormality in 39.4% cases. Most of the patients were treated with monotherapy. Phenytoin, phenobarbitone and carbamazepine were the common drug used. Out of 246 cases who were started on anticonvulsant therapy prior to referral, the choice of drug was wrong in 78 (31.7%) cases and dose was inappropriate in 121 (49.2%) cases. It was concluded that most important factor for cost effective management of epilepsy is proper clinical evaluation and education of general physicians in this direction.

Prevalence of epilepsy in a rural community of Guatemala

We conducted a cross-sectional epidemiological study to assess the prevalence and patterns of epilepsy in a small rural village of Guatemala (population 2,111); 1,882 subjects (97.3%) were surveyed. By adminIstering the World Health Organization (WHO) standard questionnaire and performing neurological examinations, we detected 16 cases of epilepsy. The crude prevalence rate for this community was 8.5 in 1,000 general population for this form. The most common type of seizure was generalized tonic-clonic seizures (GTCS, 50%), followed by complex partial seizures (CPS, 37.5%), simple partial seizures (SPS, 6.2%) and generalized atonic seizures (6.2%). The age-specific prevalence ratio was highest among the group aged 20-29 years, although the difference between that group and the other age groups was not statistically signifICant (z<2, P>0.05). Fourteen persons (87.5%) had sought medical care for their seizures at least once in their lifetime, 5 (31.25%) were receiving an antiepileptic drug (AED), and 9 (56.25%) had previously received treatment and 2 (12.5%) had never been treated for their illness. Phenobarbital was the most common AED prescribed; 7 persons had positive family history of epilepsy, 5 reported a history of significant head trauma, 4 had history of central nervous system disease, and 1 had a history of chronic alcohol intake.

The prevalence of neurological disorders among children in Gemlik (Turkey)

With a descriptive survey, the authors tried to ascertain the prevalence of certain neurological disorders among children aged up to five years. Questionnaires were administered to mothers and their children were divided into two groups (559 children): neurologically healthy and suspect. Suspect children were examined by a paediatrician, who assigned a diagnosis where appropriate (361 children). A control group was selected from the healthy children (420 children), and they were neurologically examined with the suspect children. Cases and controls were compared for family history, and pregnancy and delivery risks. The most frequent condition found was febrile convulsions (0.45 per cent), followed by epilepsy (0.9 per cent) and cerebral palsy (0.5 per cent).

Epilepsy in Pakistan: a population-based epidemiologic study

A house-to-house, cross-sectional, population study of epilepsy on 24,130 individuals of all ages from southern Pakistan indicates an age-specific prevalence rate of 9.99 in 1,000 (14.8 in 1,000 in rural and 7.4 in 1,000 in urban areas) for recurrent, nonfebrile "active" epilepsy in Pakistan. Mean onset of epilepsy was 13.3 years, and 74.3% epileptic persons were aged < 19 years at onset of the disorder. The most common seizure type was tonicclonic in 77% [primary generalized tonic-clonic (GTC) in 59% and secondarily generalized in 18%], simple partial (SPS) in 5%, complex partial (CPS) in 6%, generalized absence in 1%, tonic in 3%, and myoclonic in 3% cases. Multiple seizures types in the same person were evident in 9.6% of only the generalized group. A putative cause could be suggested in 38.4% of cases: 32% had a positive family history of epilepsy, most common among siblings. Common perceived precipitants included fever in 29.2% and emotional disturbances in 16.6%. Only 3% of epileptic persons believed that their illness was due to super-natural causes. Treatment status was very poor, with only 2% rural and 27% urban epileptic persons receiving antiepileptic drugs (AEDs) at the time of the survey. We discuss the logistic and management problems of population-based epidemiologic studies in developing countries.

The prevalence and incidence of convulsive disorders in children

Each year, about 150,000 children and adolescents in the United States will come to medical attention for evaluation of a newly occurring seizure disorder of some type. Between 2% and 4% of all children in Europe and the United States experience at least one convulsion associated with a febrile illness before the age of 5 years. The cumulative incidence of febrile convulsions among children ranges from about 1% in China to more than 8% in Japan and 14% in Guam. The peak incidence of a first febrile convulsion occurs in the second year of life. Between 0.5% and 1% of children and adolescents experience a seizure associated with other acute metabolic or neurologic insults; most of these occur in the neonatal period. The incidence of epilepsy (recurrent unprovoked seizures) in children and adolescents seems relatively consistent across all populations studied, ranging from 50 to 100/100,000. The highest incidence of epilepsy is in the first year of life. West syndrome accounts for about 2% of all childhood epilepsy. Lennox-Gastaut syndrome for 1-2%, childhood absence epilepsy (pyknolepsy) for 10-15%, juvenile myoclonic epilepsy for 5%, and idiopathic localization-related epilepsy for 10%. Between 0.5 and 1% of children experience a nonrecurrent, single, unprovoked convulsive episode. Following are the estimated numbers of children and adolescents with newly diagnosed convulsive disorders in the United States for the year 1990: febrile seizures, 100,000; neonatal seizures, 4,000; other provoked seizures, 6,000; single unprovoked seizures, 10,000; and epilepsy, 30,000.

The characteristics of epilepsy in a largely untreated population in rural Ecuador

A house-to-house survey of epileptic seizures covering a population of 72,121 persons was carried out in a rural area of northern Ecuador. A cascade system of diagnosis was used to identify all cases of epileptic seizures in this population. 1029 cases were found, of whom 881 were considered to be definite cases and 148 were possible cases. Of the 1029 cases, 56% had active epilepsy. The lifetime prevalence rate was found to lie between 12.2 and 19.5/1000 and the prevalence of active cases between 6.7 and 8.0/1000. An annual incidence rate of between 122/100,000 and 190/100,000 was estimated. Seizure type was classified without EEG data and almost half of the cases had partial seizures. In 27% of cases an aetiology was proposed on clinical grounds. This is one of few reported studies of a population that has been largely unexposed to antiepileptic drugs, providing an opportunity to study the natural history of the untreated condition. It has been suggested that treatment in newly developing epilepsy will prevent its development to a chronic condition. Only 37% of the 1029 cases had ever received antiepileptic drugs, and only 12% of the cases were taking them at the time of the survey. Despite this, a high rate of inactivity was observed, with 44% of all cases free of seizures. Nearly two thirds of the inactive cases identified had never received treatment with antiepileptic drugs. In a subgroup of untreated cases with an active condition, treatment with antiepileptic drugs was initiated and was highly effective even in cases with a long previous history. Thus the findings from this study suggest that the development of epilepsy resistant to therapy is not always associated with a long duration of untreated epilepsy.

Prevalence of epilepsy in Kelibia, Tunisia

A door-to-door survey was made in Kelibia, Tunisia to determine the prevalence of major neurologic disorders, including epilepsy. The survey was made according to a World Health Organization (WHO) protocol (1981). All individuals responding positively to the screening tool were examined by a neurologic team using well-defined diagnostic criteria. One hundred forty-one individuals, alive on prevalence day (July 1, 1985), were identified as having active epilepsy, giving a crude prevalence ratio of 4.04 per 1,000 and an age-adjusted (on WHO population) prevalence ratio of 3.64 per 1,000. Prevalence ratios increase with age (in children and young adults with the highest prevalence ratio at approximately 20 years) and decrease after 40 years. The most frequently identified type was generalized convulsive seizures (93%). The most frequently associated conditions were cerebral palsy and mental retardation.

Some aspects of prognosis in the epilepsies: a review

The traditional view that epilepsy is usually a chronic condition in which the prognosis is consistently poor has been challenged in the last 2 decades. Evidence from population-based studies and from intervention studies in newly diagnosed patients has produced a wealth of information of a much better prognosis. It is now generally accepted that as many as 70-80% of people developing seizures for the first time will eventually achieve terminal remission, whereas the remaining 20-30% will continue to have recurrent seizures despite all treatment. Despite the high recurrence rate after a first epileptic seizure, remission usually occurs early and for most persons, epilepsy is a short-lived condition. The exact role of antiepileptic drugs (AEDs) in this good outcome, however, remains open to debate, because the natural history of the untreated condition is largely unknown. In this article, factors that may influence the prognosis of the epilepsies, including the problems of diagnosis, are reviewed. Special emphasis is given to the issue of spontaneous remission and the question of prognosis of different epileptic syndromes.

Classification of epileptic seizures: a hospital-based study of 1,250 patients in a developing country

The 1981 International Classification of Epileptic Seizures (ICES) was used to study the distribution of seizure types in 1,250 patients attending an Epilepsy Clinic in Sri Lanka. Based on seizure symptomatology 94.6% of the cases could be classified, and by adding the routine interictal EEG findings the percentage of classifiable seizures increased to 97%. Partial seizures (73.8% cases) were three times as common as generalized seizures (23.3% cases). Of the partial seizures, simple partial seizures (SPS) accounted for only 0.4% cases, and complex partial seizures (CPS) for 8.8%, whereas partial seizures secondarily generalized (PSGS) accounted for 64.6%. PSGS had simple onset in 12.5% and complex onset in 34.8% of cases. Myoclonic seizures were the commonest of the generalized seizures, accounting for 14.6% of all cases. Tonic-clonic seizures accounted for 7.4% of cases; absence seizures accounted for only 1.3%. The study showed the 1981 ICES to be relevant and applicable in a clinical setting with limited investigatory facilities. Difficulties encountered with regard to certain subcategories could be overcome with minor modifications which made the classification operative. Routine EEG confirmed the diagnosis in a significant number of cases but changed the diagnosis in only a few, confirming that a good standardized questionnaire is the key instrument for classifying epileptic seizures.

Seizure disorders: the changes with age

Age has a profound influence on our approach to the convulsive disorders. Age is a variable which is an important determinant for risk factors for epilepsy. Age, as a surrogate of brain maturation, is a determinant of the specific characteristics of the seizure disorder in those with epilepsy, and age-related changes in these manifestations can be identified. Age is a determinant for the occurrence of acute symptomatic seizures in several types of metabolic or central nervous system insults. Age is a determinant for prognosis, whether one considers remission, medication withdrawal in those entering remission, relapse following prolonged remission, or mortality. Last, age per se seems to be a risk factor for epilepsy independent of other factors. This seems particularly true for partial seizures.

Prevalence of epilepsy in adults in northern Sweden

A multisource medical register review identified persons with active epilepsy in northern Sweden. Seven hundred thirteen persons aged greater than or equal to 17 years with epilepsy were determined on the prevalence day, December 31, 1985. The overall prevalence was 553 in 100,000 (566 in 100,000 if adjusted to the 1980 U.S. population). The ratio of males to females was 1.1, with a male prevalence of 575 and a female prevalence of 530 in 100,000. Age-specific prevalences varied between 530-644 in 100,000 except in persons aged greater than or equal to 70 years, for whom the prevalence was 321 in 100,000. Partial seizures were most common, 333 in 100,000, of whom the majority (250 in 100,000) had seizures that occasionally were secondarily generalized. Mental retardation was the foremost coexistent disorder, noted in 23%. The mean yearly seizure frequency was higher in persons with mental retardation than in nonretarded persons. Seventeen percent had seizures during the last week, 57% during the last year, whereas 16% had greater than or equal to 5 years' freedom from seizures. Most had onset of epilepsy before age 20 years. A presumed etiology was noted in 35%, more often in men than in women. Cerebrovascular disease was the most commonly identified presumed cause. Other nonepileptic diseases/disabilities were noted in 47%.

Estimates of the prevalence of childhood seizure disorders in communities where professional resources are scarce: results from Bangladesh, Jamaica and Pakistan

Although numerous estimates of the prevalence of seizure disorders in populations in the less developed world have now been published, these estimates are difficult to interpret due to lack of comparability of study methods and criteria for case definition. The results reported in this paper are from a large, collaborative study of disabilities in 2- to 9-year-old children in which standard research procedures and case definitions were used in three diverse populations (located in Bangladesh, Jamaica and Pakistan). A two-phase study design (screening followed by professional evaluations) was used in this study allowing for the professional evaluation to serve as the criterion in the estimation of prevalence, even for rare disorders. As a result, the prevalence estimates reported here have a high degree of comparability across populations and exhibit unusually strong validity for population surveys. Febrile seizures were the most common type of seizure history in all three populations, with point estimates of lifetime prevalence ranging from 10.9 to 62.8 per 1000. The lifetime prevalence rates of epilepsy (recurrent unprovoked seizures) ranged from 5.8 to 15.5 per 1000. Lifetime prevalence rates of neonatal, all provoked and all unprovoked seizures, as well as estimates of the prevalence of active epilepsy, are also reported.

A descriptive study of epilepsy in the district of El Salvador, Chile, 1984-1988

To describe the epidemiological characteristics of epilepsy in a northern area of Chile, an investigation was conducted in four localities in the province of Copiapó (population of 17,694). Based on 314 cases of active epilepsy, the prevalence per 1000 at June 30, 1988 was 17.7. The average annual incidence for the period 1984-1988 was 113 per 100,000. Partial seizures were the most frequent type of seizure diagnosed (54.1%). Antecedents considered as possible etiological factors were found in 29.9% of cases. According to age of onset, 64.6% had their first attack before 15 years. Middle and low socioeconomic classes had higher prevalence rates of epilepsy. We compare our results with previous Latin-American studies.

Study of the prevalence of epilepsy among schoolchildren in Valladolid, Spain

A population study was performed to estimate the prevalence of epilepsy in the juvenile population of Valladolid, Spain. Using a mixed questionnaire (postal-domiciliary), we studied a sample of 5,100 primary school pupils (aged between 6 and 14 years) and 48 pupils receiving state-run special education. We also identified all the students receiving private special education and from specific special education centers belonging to the same age group (90 and 145, respectively). The prevalence of epilepsy in the school age population on December 1, 1987 was estimated at 5.72/1,000 inhabitants. Our results are comparable to those of other studies in Western countries.