Prevalence, Incidence, and Etiology of Epilepsies in Rural Honduras: The Salama Study

Epilepsy Care in Latin America and the Caribbean: Overcoming Challenges and Embracing Opportunities

The burden of epilepsy in the Latin America and the Caribbean (LAC) region causes a profound regional impact on the health care system and significantly contributes to the global epilepsy burden. As in many other resource-limited settings worldwide, health care professionals and patients with epilepsy in LAC countries face profound challenges due to a combination of factors, including high disease prevalence, stigmatization of epilepsy, disparities in access to care, limited resources, substantial treatment gaps, insufficient training opportunities for health care providers, and a diverse patient population with varying needs. This article presents an overview of the epidemiology of epilepsy and discusses the principal obstacles to epilepsy care and key contributors to the epilepsy diagnosis and treatment gap in the LAC region. We conclude by highlighting various initiatives across different LAC countries to improve epilepsy care in marginalized communities, listing strategies to mitigate treatment gaps and facilitate better health care access for patients with epilepsy by enhancing the epilepsy workforce.

Epilepsy and neurocysticercosis in rural areas of the Bolivian Chaco: What has changed during the last 30 years?

OBJECTIVE

Neurocysticercosis (NCC) is considered the major cause of epilepsy in endemic regions. In the rural areas of the Bolivian Chaco prevalence of NCC among people with epilepsy (PWE) was 27.4%, according to a population-based survey carried out in 1994. The aim of the study was to estimate the prevalence of Epilepsy Associated with Tonic-Clonic Seizures (EATCS) and to evaluate the prevalence of NCC among PWE in the rural communities of the Bolivian Chaco after 30 years.

METHODS

Twenty-two rural communities (total population 12 852) were involved in the study. PWE in the study area were ascertained by multiple sources and the diagnosis was confirmed by a neurologist. All PWE identified were invited to undergo brain CT scan examination and diagnosis of NCC was sought according to the revised Del Brutto criteria.

RESULTS

Seventy-eight PWE (30 men, 38.4%; mean age at onset was 12.7 ± 13.2 years) with EATCS were identified giving a crude prevalence of 6.1/1000 (95% CI: 4.7-7.3). Due to the COVID-19 lockdown, the study was interrupted in 2020 and only 36 PWE (46%) of the whole sample underwent CT scan examination. Of these, 8 (22.2%) fulfilled the criteria for NCC of whom 6 (75%) presented only single or multiple calcifications.

SIGNIFICANCE

This is the first study reassessing the prevalence of NCC among PWE after 30 years, in the same rural area and using a population-based design. T. solium is still endemic in the Bolivian Chaco where more than 20% of EATCS may be attributable to NCC. Our findings show a substantially unchanged prevalence of NCC over the past 30 years despite improved knowledge, underlining the need for active intervention programs to control T. solium transmission in this area.

PLAIN LANGUAGE SUMMARY

Neurocysticercosis is still endemic in the Bolivian Chaco. The proportion of epilepsy attributable to neurocysticercosis is about 22%. Systematic efforts towards elimination of neurocysticercosis in these areas should be implemented.

The epidemiology of epilepsy in older adults: A narrative review by the ILAE Task Force on Epilepsy in the Elderly

In an aging world, it is important to know the burden of epilepsy affecting populations of older persons. We performed a selective review of epidemiological studies that we considered to be most informative, trying to include data from all parts of the world. We emphasized primary reports rather than review articles. We reviewed studies reporting the incidence and prevalence of epilepsy that focused on an older population as well as studies that included a wider age range if older persons were tabulated as a subgroup. There is strong evidence that persons older than approximately 60 years incur an increasing risk of both acute symptomatic seizures and epilepsy. In wealthier countries, the incidence of epilepsy increases sharply after age 60 or 65 years. This phenomenon was not always observed among reports from populations with lower socioeconomic status. This discrepancy may reflect differences in etiologies, methods of ascertainment, or distribution of ages; this is an area for more research. We identified other areas for which there are inadequate data. Incidence data are scarcer than prevalence data and are missing for large areas of the world. Prevalence is lower than would be expected from cumulative incidence, possibly because of remissions, excess mortality, or misdiagnosis of acute symptomatic seizures as epilepsy. Segmentation by age, frailty, and comorbidities is desirable, because "epilepsy in the elderly" is otherwise too broad a concept. Data are needed on rates of status epilepticus and drug-resistant epilepsy using the newer definitions. Many more data are needed from low-income populations and from developing countries. Greater awareness of the high rates of seizures among older adults should lead to more focused diagnostic efforts for individuals. Accurate data on epilepsy among older adults should drive proper allocation of treatments for individuals and resources for societies.

Status of epilepsy in the tropics: An overlooked perspective

Epilepsy is one of the most common serious chronic neurological diseases affecting people of all ages globally. It is characterized by recurrent seizures. About 50 million people worldwide have epilepsy. Indubitably, people with epilepsy (PWE) may be without access to appropriate treatment. Many studies have examined the molecular mechanisms and clinical aspects of epilepsy; nonetheless, the treatment gap exists in some special areas. In the tropics, the specific geographical and ecological conditions and a lack of medical resources result in neglect or delay of diagnosis for PWE. Herein, we summarized the epidemiology of epilepsy in the tropics and discussed the disease burden and existing problems, aiming to offer a medical environment for patients in need and highlight the importance of reducing the epileptic disease burden in tropical countries.

Seizures Related to Neurocysticercosis and Cocaine Use

Neurocysticercosis (NCC) is an infection of the central nervous system with Taenia solium cysts that most commonly results in seizures. In stable patients without recent symptoms, these seizures may be provoked by seizure threshold-lowering drugs such as cocaine. This case details a 38-year-old male with a past medical history of epilepsy presenting with seizures due to comorbid NCC and cocaine use. This case was complicated by the lack of available information regarding the patient’s past medical history and medication use. We highlight the importance of obtaining a full work-up, including brain imaging, to provide optimal treatment for patients with seizures despite a history of drug use.

The worldwide epilepsy treatment gap: A systematic review and recommendations for revised definitions - A report from the ILAE Epidemiology Commission

OBJECTIVE

In order to more appropriately apply and understand the "epilepsy treatment gap" (ETG) concept in current health systems, revised conceptual and operational definitions of ETG are timely and necessary. This article therefore systematically reviews worldwide studies of the ETG, distinguishing high-, middle-, and low-income regions, and provides recommendations for an updated International League Against Epilepsy (ILAE) definition of ETG.

METHODS

A systematic review of the ETG was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. The search was conducted from January 1990 to July 2019, in the online databases of Ovid MEDLINE and Embase. Identified abstracts were reviewed in duplicate and data independently extracted using a standard proforma. Data describing treatment gap information including both diagnostic and therapeutic aspects of access to epilepsy treatment were recorded. Descriptive statistics are presented.

RESULTS

The treatment gap reported in the 45 distinctive populations represented 33 countries. Treatment gap definitions varied widely. The reported ETGs ranged broadly from 5.6% in Norway to 100% in parts of Tibet, Togo, and Uganda. The wide range of reported ETGs was multifactorial in origin including true differences in the availability and utilization of health care among study populations, variations in operational definitions of the epilepsy treatment gap, and methodological differences in sampling and identifying representative epilepsy cases in populations. Significance and recommendations For the ETG to be a useful metric to compare levels of unmet epilepsy care across different countries and regions, a standardized definition must be adapted, recognizing some of the limitations of the current definitions. Our proposed definition takes into account the lack of effective health care insurance, the diagnostic gap, the therapeutic gap, quality-of-care, and other unmet health care needs."

Factors not considered in the study of drug-resistant epilepsy: Psychiatric comorbidities, age and gender

In basic research and clinical practice, the control of seizures has been the most important goal but it should not be the only one. There are factors that remain poorly understood in the study of refractory epilepsy such as the age and gender of patients and the presence of psychiatric comorbidities. It is known that in patients with drug-resistant epilepsy (DRE), the comorbidities contribute to the deterioration of the quality of life, increase the severity, and worsen the prognosis of epilepsy. Some studies have demonstrated that patients diagnosed with a co-occurrence of epilepsy and psychiatric disorders are more likely to present refractory seizures and the probability of seizure remission after pharmacotherapy is reduced. The evidence of this association suggests the presence of shared pathogenic mechanisms that may include endocrine disorders, neuroinflammatory processes, disturbances of neurotransmitters and mechanisms triggered by stress. Additionally, significant demographic, clinical and electrographic differences have been observed between women and men with epilepsy. Epilepsy affects the female gender in a greater proportion, although there are no studies that report whether refractoriness affects more females. The reasons behind these sex differences are unclear; however, it is likely that sex hormones and sex brain differences related to chromosomal genes play an important role. On the other hand, it has been shown in industrialized countries that prevalence of DRE is higher in the elderly when compared to youngsters. Conversely, this phenomenon is not observed in developing regions, where more cases are found in children and young adults. The correct identification and management of these factors is crucial in order to improve the quality of life of the patients.

Risk factors associated with new-onset epilepsy in young adults: Population-based study

OBJECTIVE

Risk factors for childhood and late-onset epilepsy are thoroughly described in existing literature, while they are less defined and ambiguous for young adults. We aimed to evaluate the prevalence of various risk factors associated with new-onset epilepsy in adults aged 20-49 years. We included all incident cases in North Macedonia between 2015 and 2018.

METHODS

Study participants were ascertained through the nationwide healthcare platform. We performed a retrospective analysis of their Electronic Health Records and identified associated conditions which are considered putative risk factors for epilepsy.

RESULTS

Of 1691 included patients, 694 (41%) had at least one putative risk factor. The most common were neoplasms and cerebrovascular diseases (8% of cases, respectively), followed by intellectual disability (6%), alcohol/substance abuse (5%), and traumatic brain injury (4%). Infective and inflammatory diseases were infrequent in our cohort (1%). Other very rare risk factors included degenerative and metabolic disorders and malformations of cortical development (2%). Idiopathic (genetic) generalized epilepsies accounted for 7% of incident cases. Chronic alcoholism and illicit drugs abuse (dominantly opioids) were significantly more frequent in males than in females (p < 0.00001).

CONCLUSION

Brain neoplasms and stroke were the most prevalent risk factors associated with new-onset epilepsy in young adults. Furthermore, adult-onset IGE were common in our cohort. The majority of patients did not have any of conventional risk factors and probably specific genetic causes might become increasingly recognized in adult-onset epilepsies in the future.

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.

Current Diagnostic Criteria for Neurocysticercosis

Neurocysticercosis (NCC) causes significant neurological morbidity around the world, and is the most common preventable factor for epilepsy in adults. It is endemic in most developing countries, and also diagnosed with some frequency in industrialized countries because of travel and migration. The clinical manifestations of NCC are extremely variable and may include almost any neurological symptom, depending on the number of lesions, location, size and evolutive stage of the infecting parasitic larvae and the immune response of the host. Thus, the diagnosis of NCC relies mostly on neuroimaging and immunological tests. Despite being a disease with a known etiology, the lack of specificity of clinical manifestations and auxiliary examinations makes its diagnosis difficult. In an attempt for developing a standard diagnosis approach, a chart of diagnostic criteria for NCC was initially published in 1996, and revised in 2001 and 2017. This chart of diagnostic criteria systematized the diagnosis of NCC and became widely used worldwide. This manuscript describes the structure of the chart, the principles behind the changes for each revision, as well as the context of its use and potential for improvement.

Incidence and prevalence of epilepsy in the Republic of North Macedonia: Data from nationwide integrated health care platform

PURPOSE

This study aimed to evaluate the incidence and period prevalence of epilepsy in the Republic of North Macedonia, an upper-middle-income country with universal access to healthcare, based on a nationwide healthcare platform (NHP).

METHODS

NHP contains reports from all inpatient and outpatient medical encounters and procedures, and all electronic medical records are linked together with a unique patient number. We performed the analysis of the data maintained at the Macedonian Ministry of Health, concerning the five years of the study (2014 through 2018). Population and demographic data for each year were obtained from the State Statistical Office.

RESULTS

The period prevalence was 6.67 per 1,000 inhabitants. There were 6383 (46.2%) females and 7435 (53.8%) males; the gender difference was significant: 6.17 per 1,000 females and 7.16 per 1,000 males (p = 0.0000). Between 2015 and 2018 the median annual incidence of epilepsy was 68 new epilepsy patients per 100,000, with an upward trend over time. The age-specific incidence was high in childhood and adolescence, was constant (and low) in the adult years, and gradually increased in each successive age group after the age of 50 years. The greatest incidence was found in group 70-79 years of age. The incidence in childhood and adolescence tends to gradually decrease from 2015 to 2018, while it progressively increased in population over 50 years of age, which may explain a rise in overall incidence. We found a statistically significant higher incidence in males than in females, a ratio consistently being 1.2: 1.

CONCLUSION

The data from the study provides accurate findings on the prevalence and incidence of epilepsy in the upper-middle-income Southeastern European country.

Prevalence and incidence of epilepsy in Latin America and the Caribbean: A systematic review and meta-analysis of population-based studies

OBJECTIVE

This study was undertaken to perform an updated systematic review and meta-analysis to estimate the pooled prevalence and incidence of epilepsy in Latin America and the Caribbean (LAC), describing trends over time, and exploring potential clinical and epidemiological factors explaining the heterogeneity in the region.

METHODS

Observational studies assessing the incidence or prevalence of epilepsy in LAC countries up to March 2020 were systematically reviewed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Meta-analyses and cumulative analyses were performed using random-effects models. We assessed between-study heterogeneity with sensitivity, subgroup, and meta-regression analyses. Moreover, the quality of the included studies and the certainty of evidence were evaluated using the GRADE (grading of recommendation, assessment, development, and evaluation) approach.

RESULTS

Overall, 40 studies (from 42 records) were included, 37 for prevalence analyses and six for incidence (312 387 inhabitants; 410 178 person-years). The lifetime prevalence was 14.09 per 1000 inhabitants (95% confidence interval [CI] = 11.72-16.67), for active epilepsy prevalence was 9.06 per 1000 individuals (95% CI = 6.94-11.44), and the incidence rate was 1.11 per 1000 person-years (95% CI = .65-1.70). These high estimates have been constant in the region since 1990. However, substantial statistical heterogeneity between studies and publication bias were found. The overall certainty of evidence was low. Methodological aspects (sample size) and countries' epidemiological characteristics such as access to sanitation services and child and adult mortality rates explained the high heterogeneity. Finally, the prevalence of epilepsy associated with neurocysticercosis (NCC) in the general population was high, and the proportion of NCC diagnosis among people living with epilepsy was 17.37%.

SIGNIFICANCE

The epilepsy prevalence and incidence in LAC are higher than worldwide estimates, being constant since 1990 and strongly influenced by NCC. We identified high between-study heterogeneity and significant methodological limitations (e.g., heterogeneous definitions, lack of longitudinal studies). The region needs upgraded research using standardized definitions and diagnostic methods, and urgent action against preventable causes.

Increasing Trends in the Incidence and Prevalence of Epilepsy in Korea

BACKGROUND AND PURPOSE

There have been few reports on recent trends in the occurrence of epilepsy. The aim of this study was to estimate the incidence and prevalence of epilepsy and analyze their annual trends in Korea over the period 2009-2017.

METHODS

This nationwide population-based study was carried out using the National Health Insurance Service of Korea database. A prevalent case was defined as one of a patient receiving a prescription of anticonvulsants under the diagnostic codes for epilepsy or seizure. An incident case was ascertained by confirming the absence of any epilepsy-related diagnostic codes and anticonvulsant prescription for 2 years or more before the operational definition for a prevalent case was met. Alternative operational definitions for epilepsy were tested. The temporal trends of the incidence and prevalence of epilepsy were analyzed using a Poisson regression model, and are expressed as average annual percentage changes (AAPCs).

RESULTS

The incidence of epilepsy increased from 28.7/100,000 persons in 2009 to 35.4/100,000 persons in 2017. The prevalence increased gradually from 3.4/1,000 persons in 2009 to 4.8/1,000 persons in 2017. These increasing trends were more evident among elderly subjects aged ≥75 years and in those who had codes for epilepsy or seizure as an additional diagnosis. Age standardization revealed a less prominent but still increasing trend in both incidence (AAPC=0.48%) and prevalence (AAPC=3.11%).

CONCLUSIONS

There have been increasing trends in both the prevalence and incidence of epilepsy in Korea between 2009 and 2017. This finding appears to be related to societal aging and the high incidence of symptomatic epilepsy in the elderly population.

Clinical characteristics of epilepsy in resource-limited communities in Punjab, Northwest India

OBJECTIVES

To describe clinical characteristics of a community-based epilepsy cohort from resource-limited communities in Punjab, Northwest India.

METHODS

The cohort was gathered following a two-stage screening survey. We cross-sectionally examined and followed up the cohort for one year. A panel of neurologists assigned seizure types, syndromes, and putative etiologies and categorized drug responsiveness.

RESULTS

The cohort of 240 included 161 (67.1%) men, 109 (45.4%) illiterates and 149 (62.1%) unemployed. Current age was >18 years in 155 (64.6%) but age at epilepsy onset was <18 years in 173 (72.1%). Epilepsies due to structural and metabolic causes were diagnosed in 99 (41.3%), but syndromic assignments were not possible in 97 (40.4%). After one year, drug-resistant epilepsy was established in 74 (30.8%). Perinatal events (n = 35; 14.6%) followed by CNS infections (n = 32; 13.3%) and traumatic brain injury (n = 12; 5.0%) were common risk factors. Most of those with CNS infections (n = 19; 63.3%), perinatal antecedents (n = 23; 76.7%), and other acquired risk factors (n = 27; 90.0%) presented with epilepsy due to structural and metabolic causes. Perinatal events were the putative etiology for nearly 40.7% of generalized epilepsies due to structural and metabolic causes and 28.2% of all epilepsies with onset <10 years.

SIGNIFICANCE

Existing classifications schemes should be better suited to field conditions in resource-limited communities in low- and middle-income countries. The finding of drug-resistant epilepsy in nearly at least a third in a community-based sample underscores an unmet need for enhancing services for this segment within healthcare systems. Perinatal events, CNS infections, and head injury account for a third of all epilepsies and hence preventative interventions focusing on these epilepsy risk factors should be stepped up.

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.

Comorbidities of epilepsy in low and middle-income countries: systematic review and meta-analysis

Epilepsy is a major public health concern in low and middle-income countries (LMICs) and comorbidities aggravate the burden associated with the disease. The epidemiology of these comorbidities has not been well described, although, identifying the main comorbidities of epilepsy, and their relative importance, is crucial for improving the quality of care. Comorbidities were defined as disorders coexisting with or preceding epilepsy, or else compounded or directly attributed to epilepsy or to its treatment. A meta-analysis of the proportion of main comorbidities by subcontinent as well as overall was also conducted. Out of the 2,300 papers identified, 109 from 39 countries were included in this systematic review. Four groups of comorbidities were identified: parasitic and infectious diseases (44% of comorbid conditions), somatic comorbidities (37%), psychosocial (11%), as well as psychiatric comorbidities (8%). Heterogeneity was statistically significant for most variables then random effect models were used. The most frequently studied comorbidities were: neurocysticercosis (comorbid proportion: 23%, 95% CI: 18-29), head trauma (comorbid proportion: 9%, 95% CI: 5-15) malnutrition (comorbid proportion: 16%, 95% CI: 28-40), stroke (comorbid proportion: 1.3%, 95% CI: 0.2-7.0), and discrimination for education (comorbid proportion: 34%, 95% CI: 28-40). Many comorbidities of epilepsy were identified in LMICs, most of them being infectious.

Systematic Review and Meta-Analysis of Management Strategies and Outcomes in Adult Spinal Neurocysticercosis

OBJECTIVE

Spinal involvement in neurocysticercosis is rare and can lead to debilitating injury if not diagnosed and treated early. We aim to provide the reader with a thorough analysis of the best available evidence regarding patient characteristics, optimal treatment modality, and outcomes in cases of spinal neurocysticercosis.

METHODS

A systematic review of the literature using PubMed, Google Scholar, and Web of Science electronic databases was made according to the PRISMA guidelines. An illustrative case of intramedullary-cervical spinal disease is also presented for illustrative purposes.

RESULTS

A total of 46 reports of 103 patients fitting the screening criteria were identified. Isolated spinal involvement was seen in 46.15% of patients. Most infections (76.92%) had an intradural extramedullary localization, with 43.27% of cases involving >1 spinal cord level. The most common presenting symptoms were motor deficits (77.88%), pain syndromes (64.42%), and sensory deficits (53.85%). Combined surgical resection and pharmacologic therapy was the most frequently used treatment modality (49.04%) and had the highest proportion of patients reporting symptomatic improvement at follow-up (78.43%). Combination therapy had a significantly higher rate of neurologic recovery compared with surgery alone (P = 0.004) or medical treatment (P = 0.035).

CONCLUSIONS

Spinal involvement in neurocysticercosis should be considered in patients from or who traveled to endemic areas presenting with ring-enhancing lesions. Combined treatment with surgery followed by cysticidal and steroid medication seems to be superior to surgery or medical treatment in isolation and seems to provide the highest chances of recovery.

Feasibility of a point-of-care test based on quantum dots with a mobile phone reader for detection of antibody responses

We developed a novel and portable fluorescent sensor that integrates a lateral flow assay with a quantum dot (Qdots) label and a mobile phone reader for detection of specific antibodies in human serum. We evaluated the utility of this assay to test for antibodies to the Taenia solium rT24H antigen. It was a retrospective study by examining 112 positive human sera from patients with neurocysticercosis (NCC) including samples from patients with single viable cyst (n = 18), two or more viable cysts (n = 71), and subarachnoid (racemose) cysts (n = 23). These samples were collected from previous study subjects in Lima, Peru under an approved study protocol in Peru. The sera were made anonymous under a protocol approved by the CDC Institutional Review Board. Definitive diagnosis of the subject was established by computed-tomography and/or magnetic resonance imaging. To test the specificity of the assay, we evaluated a panel of serum samples obtained from patients with other infections (n = 24), and serum samples from persons in the United States and Egypt who had not traveled outside their country, and therefore are presumed negative for cysticercosis (n = 128). The assay specificity in the negative panel was 99% (95–100%) while assay sensitivity was 89% (79–95%) in NCC patients with two or more viable cysts. Our assay has performance characteristics similar to those of traditional platforms for the detection of NCC and shows promise as a mobile phone reader-based point-of-care test for antibody detection.

Point-of-care (POC) assays are important tools in control and elimination of parasitic diseases such as lymphatic filariasis, malaria, and leishmaniasis. Most POC assays use immunochromatographic and lateral flow assay principles with gold nanoparticles as a reporter. Assays based on gold nanoparticles usually provide qualitative or semi-quantitative results and have relatively low sensitivity. However, other reporter alternatives are available, including quantum dots (Qdots), up-converting phosphor nanoparticles, and superparamagnetic particles. We developed a Qdots-based test in a lateral flow assay format with a mobile phone reader to detect antibody responses, using neurocysticercosis (NCC) as a disease model, and found that the performance is similar to the traditional platform for detecting antibody responses in subjects with NCC. The incorporation of the mobile phone reader offers the advantage of portability and adaptability for use in areas where laboratories are not immediately accessible. This novel POC assay with mobile phone reader is a feasible option for antibody responses detection.

Prevalence, clinical characteristics, and seizure outcomes of epilepsy due to calcific clinical stage of neurocysticercosis: Study in a rural community in south India

OBJECTIVE

The objective of this research was to study the prevalence, clinical characteristics, and seizure remission rates of epilepsy due to calcific stage of neurocysticercosis (cNCC) in a rural community in south India.

MATERIAL AND METHODS

Comprehensive Rural Epilepsy Study South India (CRESSI) is a prospective longitudinal study of epilepsy care in a rural community in south India. As part of this study, prevalence of epilepsy was studied in a population of 74,086 in 22 villages. The prevalence study identified 451 people with epilepsy including 62 (13.7%) with epilepsy due to cNCC. Diagnosis of cNCC was based on computed tomography (CT) findings. The clinical characteristics and seizure outcomes were studied in this cohort of 62 patients. The data collected included demographics, seizure type, antiepileptic drugs (AEDs), seizure remission rates, and predictors of long-term seizure remissions.

RESULTS

The crude prevalence of epilepsy due to cNCC in this rural community was 0.84 per 1000 (95% confidence interval [CI]: 0.65-1.07). This lesion accounted for 41% of the established etiology among 451 prevalence cases of epilepsy. Mean age at presentation was 28.87 ± 14.45 (range: 8-65 years) with equal gender distribution. The common location of the lesion was in the perirolandic region. Focal onset motor seizures were the common seizure type. Seizure remission (≥2 years) rate was 80.3%. The independent predictor of drug resistance was failure to respond to monotherapy (odds ratio: 63.9; 95% CI: 8.4-485.4; p < 0.0001). Focal impaired awareness behavioral arrest/automatisms with lesion located in the temporal lobe in all the three patients were drug-resistant.

CONCLUSIONS

In this rural community in south India, epilepsy due to cNCC was the commonest acquired epilepsy in people aged ≥20 years. Long-term seizure remission rates were high, and failure to respond to monotherapy was the predictor of drug resistance. Drug-resistant epilepsy was extremely rare with this lesion.

Convulsive status epilepticus due to different evolutionary stages of neurocysticercosis - solitary cyticercus granuloma, low cyst load, and single calcific lesion in an endemic country: Clinical profile

PURPOSE

The aims of the study were: (a) to evaluate the clinical profile of convulsive status epilepticus (CSE) due to different evolutionary stages of neurocysticercosis (NCC), solitary cysticercus granuloma, low cyst load and single calcific lesion in an endemic country; (b) to evaluate the response of CSE to antiepileptic drugs; and (c) to evaluate long-term outcomes METHODS: A retrospective review of case records of patients with CSE due to different evaluative stages of NCC seen over a period of 18 years.

RESULTS

During 18 years period, 41 (24 males, mean age 25.3 years, range 8-65 years) patients with CSE due to different evolutionary stages of NCC were admitted to our Neurological Intensive Care Unit. There were 7 patients with 3-5 degenerative cyst load, 20 with solitary cysticercus granuloma (SCG), and 14 with single calcific (cNCC) lesion. Of the 41 patients, CSE was the initial presenting feature in 38 (93%) patients. The mean duration of CSE was 5.85 h (range 0.5-48 h). The mean duration of CSE due to single cNCC was significantly shorter when compared to the duration of CSE due to degenerative stages of NCC (1.96 + 1.39 h vs. 7.87+13.18; p < 0.026). Of the 41 patients, 39 (95%) responded to first-line treatment (intravenous (IV) benzodiazepine followed by IV phenytoin/ fosphenytoin or valproate), two patients required continuous IV midazolam. Both the patients developed aspiration pneumonia. There were no deaths, and all the 41 patients had Glasgow Outcome Score of 5 at 90-day follow-up and were back to their previous occupation.

CONCLUSIONS

This study suggests that CSE due to different evolutionary stages of NCC, SCG, low lesional load, and single calcific lesion is rare even in countries endemic to NCC and is associated with an excellent outcome.

Morphological and Advanced Imaging of Epilepsy: Beyond the Basics

The etiology of epilepsy is variable and sometimes multifactorial. Clinical course and response to treatment largely depend on the precise etiology of the seizures. Along with the electroencephalogram (EEG), neuroimaging techniques, in particular, magnetic resonance imaging (MRI), are the most important tools for determining the possible etiology of epilepsy. Over the last few years, there have been many developments in data acquisition and analysis for both morphological and functional neuroimaging of people suffering from this condition. These innovations have increased the detection of underlying structural pathologies, which have till recently been classified as "cryptogenic" epilepsy. Cryptogenic epilepsy is often refractory to anti-epileptic drug treatment. In drug-resistant patients with structural or consistent functional lesions related to the epilepsy syndrome, surgery is the only treatment that can offer a seizure-free outcome. The pre-operative detection of the underlying structural condition increases the odds of successful surgical treatment of pharmacoresistant epilepsy. This article provides a comprehensive overview of neuroimaging techniques in epilepsy, highlighting recent advances and innovations and summarizes frequent etiologies of epilepsy in order to improve the diagnosis and management of patients suffering from seizures, especially young patients and children.

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.

The primary prevention of epilepsy: A report of the Prevention Task Force of the International League Against Epilepsy

Among the causes of epilepsy are several that are currently preventable. In this review, we summarize the public health burden of epilepsy arising from such causes and suggest priorities for primary epilepsy prevention. We conducted a systematic review of published epidemiologic studies of epilepsy of 4 preventable etiologic categories-perinatal insults, traumatic brain injury (TBI), central nervous system (CNS) infection, and stroke. Applying consistent criteria, we assessed the quality of each study and extracted data on measures of risk from those with adequate quality ratings, summarizing findings across studies as medians and interquartile ranges. Among higher-quality population-based studies, the median prevalence of active epilepsy across all ages was 11.1 per 1000 population in lower- and middle-income countries (LMIC) and 7.0 per 1000 in high-income countries (HIC). Perinatal brain insults were the largest attributable fraction of preventable etiologies in children, with median estimated fractions of 17% in LMIC and 15% in HIC. Stroke was the most common preventable etiology among older adults with epilepsy, both in LMIC and in HIC, accounting for half or more of all new onset cases. TBI was the attributed cause in nearly 5% of epilepsy cases in HIC and LMIC. CNS infections were a more common attributed cause in LMIC, accounting for about 5% of all epilepsy cases. Among some rural LMIC communities, the median proportion of epilepsy cases attributable to endemic neurocysticercosis was 34%. A large proportion of the overall public health burden of epilepsy is attributable to preventable causes. The attributable fraction for perinatal causes, infections, TBI, and stroke in sum reaches nearly 25% in both LMIC and HIC. Public health interventions addressing maternal and child health care, immunizations, public sanitation, brain injury prevention, and stroke prevention have the potential to significantly reduce the burden of epilepsy.

The epidemiological and clinical characteristics study on epilepsy in 8 ethnic groups of China

To survey the epidemiological characteristics and clinical features on epilepsy in eight ethnic groups in Yunnan province of China.

METHODES

The investigation was based on the WHO questionnaire and ICBERG screening questionnaire. This study was performed through random cluster sampling and door-to-door survey.

RESULTS

A total of 76,302 individuals from eight ethnic groups were surveyed. The crude prevalence of epilepsy ranged from 1.2/1000 to 6.5/1000 in the eight ethnic groups, and the age-adjusted prevalence of epilepsy was from 2.1/1000 to 7.3/1000. The prevalence of active epilepsy varied from 1.0/1000 to 5.2/1000 in the eight ethnic groups, and the age-adjusted prevalence of active epilepsy was from 1.8/1000 to 6.7/1000. The age peak for seizures was below twenty, the patients of 61.1%-95.0% suffered from generalized seizures and 5%-21.2% had partial seizures. More than 60% of the cases in five ethnic groups, and the frequency of seizures were more than 10 events per year. More than 50% in other three ethnic groups, and the seizures had occurred less than 10 events per year. The treatment gap for active epilepsy ranged from 43.7% to 100.0% among the eight ethnic groups, while the natural remission rate varied from 5.6% to 21.0%.

CONCLUSION

There were both disparity and similarity in the epidemiological and clinical features of epilepsy in different ethnic group communities.

Clinical presentation of neurocysticercosis-related epilepsy

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system and a major risk factor for seizures and epilepsy. Seizure types in NCC vary largely across studies and seizure semiology is poorly understood. We discuss here the studies regarding seizure types and seizure semiology in NCC, and examine the clinical presentation in patients with NCC and drug-resistant epilepsy. We also provide evidence of the role of MRI and EEG in the diagnosis of NCC-related epilepsy. Focal seizures are reported in 60-90% of patients with NCC-related epilepsy, and around 90% of all seizures registered prospectively are focal not evolving to bilateral tonic-clonic seizures. A great number of cases suggest that seizure semiology is topographically related to NCC lesions. Patients with hippocampal sclerosis and NCC have different clinical and neurophysiological characteristics than those with hippocampal sclerosis alone. Different MRI protocols have allowed to better differentiate NCC from other etiologies. Lesions' stages might account on the chances of finding an interictal epileptiform discharge. Studies pursuing the seizure onset in patients with NCC are lacking and they are specially needed to determine both whether the reported events of individual cases are seizures, and whether they are related to the NCC lesion or lesions. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".

Mapping occurrence of Taenia solium taeniosis/cysticercosis and areas at risk of porcine cysticercosis in Central America and the Caribbean basin

Background

This study aimed to map the occurrence of Taenia solium taeniosis/cysticercosis at national level within Central America and the Caribbean basin, and to map the distribution of porcine cysticercosis at first-level administrative subdivision level (department level) and the porcine population at risk. This zoonotic parasite is believed to be widely endemic across most of Latin America. However, there is little information readily available for Central America and the Caribbean basin. Taenia solium has been ranked the most important foodborne parasitic hazard globally and within endemic areas is a common cause of preventable epilepsy.

Methods

We conducted a structured literature search in PubMed, supplemented and crossed-referenced with relevant academic databases, grey literature, and active searches in identified literature, to identify all records of T. solium presence in Central America and the Caribbean basin between 1986 and April 2017. To retrieve grey literature, government entities, researchers and relevant institutions across the region were contacted in an attempt to cover all countries and territories. Identified records containing data on porcine cysticercosis were geo-referenced to identify department level distribution and compared to modelled distributions of pigs reared under extensive production systems.

Results

We identified 51 records of T. solium at the national level, covering 13 countries and an additional three countries were included based on World Organisation for Animal Health (OIE) reports, giving a total of 16 countries out of 41 with evidence of the parasite’s presence. Screening records for porcine cysticercosis data at the departmental level confirmed porcine cysticercosis presence in 11 departments across six countries (Colombia, Guatemala, Honduras, Mexico, Nicaragua and Venezuela).

Conclusions

When comparing these results to areas where pigs were kept in extensive production systems and areas where no information on porcine cysticercosis exists, it is apparent that porcine cysticercosis is likely to be underreported, and that a substantial part of the regional pig population could be at risk of contracting porcine cysticercosis. More detailed information on the distribution of T. solium and accurate burden estimations are urgently needed to grasp the true extent of this zoonotic parasite and the public health and agricultural problems it potentially poses.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2362-7) contains supplementary material, which is available to authorized users.

On the relationship between calcified neurocysticercosis and epilepsy in an endemic village: A large-scale, computed tomography-based population study in rural Ecuador

OBJECTIVE

Using a large-scale population-based study, we aimed to assess prevalence and patterns of presentation of neurocysticercosis (NCC) and its relationship with epilepsy in community-dwellers aged ≥20 years living in Atahualpa (rural Ecuador).

METHODS

In a three-phase epidemiological study, individuals with suspected seizures were identified during a door-to-door survey and an interview (phase I). Then, neurologists evaluated suspected cases and randomly selected negative persons to estimate epilepsy prevalence (phase II). In phase III, all participants were offered noncontrast computed tomography (CT) for identifying NCC cases. The independent association between NCC (exposure) and epilepsy (outcome) was assessed by the use of multivariate logistic regression models adjusted for age, sex, level of education, and alcohol intake. CT findings were subsequently compared to archived brain magnetic resonance imaging in a sizable subgroup of participants.

RESULTS

Of 1,604 villagers aged ≥20 years, 1,462 (91%) were enrolled. Forty-one persons with epilepsy (PWE) were identified, for a crude prevalence of epilepsy of 28 per 1,000 population (95% confidence interval [CI] = 20.7-38.2). A head CT was performed in 1,228 (84%) of 1,462 participants, including 39 of 41 PWE. CT showed lesions consistent with calcified parenchymal brain cysticerci in 118 (9.6%) cases (95% CI = 8.1-11.4%). No patient had other forms of NCC. Nine of 39 PWE, as opposed to 109 of 1,189 participants without epilepsy, had NCC (23.1% vs. 9.2%, p = 0.004). This difference persisted in the adjusted logistic regression model (odds ratio = 3.04, 95% CI = 1.35-6.81, p = 0.007).

SIGNIFICANCE

This large CT-based study demonstrates that PWE had three times the odds of having NCC than those without epilepsy, providing robust epidemiological evidence favoring the relationship between NCC and epilepsy.

Needs of exploring the burden of recent onset seizures due to neurocysticercosis and challenges in southeast Asia focusing on scenario in Malaysia

Seizures due to neurocysticercosis (NCC) is a neglected human-to-human transmitted disorder and an emerging problem worldwide. A substantial portion of recent onset seizures is known to be attributed to NCC in Taenia solium (T. solium) endemic areas where populations which neither raise pigs nor eat pig meat are also at risk. High prevalence of NCC causing epilepsy has been reported in the underdeveloped areas of Southeast Asia (SEA) however, only fragmentary information on its incidence is available in countries like Malaysia. In Malaysia T. solium infection was previously thought to be infrequent due to Muslim population majority and the religious prohibition of consuming pork, but it is not totally absent. There is an evident lack of knowledge and awareness of the actual burden, routes of transmission, and the impact of NCC in this region. The problem is assumed to be more prevalent particularly in cities because of the frequent inflow of possibly T. solium infected individuals or carriers among those who migrate from neighboring endemic countries to Malaysia. The issue of imported cases that are likely to be emerging in Malaysia is highlighted here. An accurate quantification of regional burdens of epilepsy due to NCC in Malaysia is warranted considering the disease emergence in its neighboring countries. It is suggested that the importance of NCC be recognized through quantification of its burden, and also to collect epidemiological data for its subsequent elimination in line of World Health Organization's mission for control of cysticercosis as a neglected tropical disease. In this review the need as well as a strategy for neuro-care center screening of epilepsy cases, and various issues with possible explanations are discussed. It is also proposed that NCC be declared as a reportable disease which is one of the eradicable public health problems in SEA.

Report of three imported cases of neurocysticercosis in Guadeloupe

BACKGROUND

Neurocysticercosis is endemic in most countries of Central and South America but has rarely been described in the French West Indies. We aimed to better understand the clinical and radiological presentation of our cases.

CASE PRESENTATION

We report three cases of neurocysticercosis in patients living in Guadeloupe, with different clinical and radiological presentations.

CONCLUSION

Given the eventuality of autochtonous transmission, the diagnosis should be considered in all patients living in Guadeloupe presenting with seizures.

Prevalence and incidence of epilepsy: A systematic review and meta-analysis of international studies

OBJECTIVE

To review population-based studies of the prevalence and incidence of epilepsy worldwide and use meta-analytic techniques to explore factors that may explain heterogeneity between estimates.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched MEDLINE and EMBASE for articles published on the prevalence or incidence of epilepsy since 1985. Abstract, full-text review, and data abstraction were conducted in duplicate. Meta-analyses and meta-regressions were used to explore the association between prevalence or incidence, age group, sex, country level income, and study quality.

RESULTS

A total of 222 studies were included (197 on prevalence, 48 on incidence). The point prevalence of active epilepsy was 6.38 per 1,000 persons (95% confidence interval [95% CI] 5.57-7.30), while the lifetime prevalence was 7.60 per 1,000 persons (95% CI 6.17-9.38). The annual cumulative incidence of epilepsy was 67.77 per 100,000 persons (95% CI 56.69-81.03) while the incidence rate was 61.44 per 100,000 person-years (95% CI 50.75-74.38). The prevalence of epilepsy did not differ by age group, sex, or study quality. The active annual period prevalence, lifetime prevalence, and incidence rate of epilepsy were higher in low to middle income countries. Epilepsies of unknown etiology and those with generalized seizures had the highest prevalence.

CONCLUSIONS

This study provides a comprehensive synthesis of the prevalence and incidence of epilepsy from published international studies and offers insight into factors that contribute to heterogeneity between estimates. Significant gaps (e.g., lack of incidence studies, stratification by age groups) were identified. Standardized reporting of future epidemiologic studies of epilepsy is needed.

Pathogenesis of Taenia solium taeniasis and cysticercosis

Taenia solium infections (taeniasis/cysticercosis) are a major scourge to most developing countries. Neurocysticercosis, the infection of the human nervous system by the cystic larvae of this parasite, has a protean array of clinical manifestations varying from entirely asymptomatic infections to aggressive, lethal courses. The diversity of clinical manifestations reflects a series of contributing factors which include the number, size and location of the invading parasites, and particularly the inflammatory response of the host. This manuscript reviews the different presentations of T. solium infections in the human host with a focus on the mechanisms or processes responsible for their clinical expression.

Disease Centered Around Calcified Taenia solium Granuloma

Taenia solium (the pork tapeworm) is present in most developing countries, where it is a frequent cause of seizures and other neurological disease. Parasitic larvae invade the human brain, establish, and eventually resolve, leaving a calcified scar. While these lesions are common in endemic regions, and most of these are clinically silent, a proportion of individuals with calcified cysticerci develop seizures from these lesions, and 30-65% of these cases are associated with perilesional edema (PE), likely due to host inflammation. This manuscript summarizes the importance, characteristics, natural history, and potential prevention and treatments of symptomatic calcified neurocysticercosis (NCC).

Epilepsy in Qatar: Causes, treatment, and outcome

OBJECTIVE

Qatar is a small country on the Eastern coast of the Arabian Peninsula. Its population is a unique mixture of native citizens and immigrants. We aimed to describe the features of epilepsy in Qatar as such information is virtually lacking from the current literature.

METHODS

We summarized information retrospectively collected from 468 patients with epilepsy seen through the national health system adult neurology clinic.

RESULTS

Epilepsy was classified as focal in 65.5% of the cases and generalized in 23%. Common causes of epilepsy were as follows: stroke (9%), hippocampal sclerosis (7%), infections (6%), and trauma (6%). Sixty-six percent of patients were receiving a single antiepileptic drug, with levetiracetam being the most frequently prescribed drug (41% of subjects). When the patients were divided by geographical background, remote infections caused the epilepsy in 15% of Asian patients (with neurocysticercosis accounting for 10%) but only in 1% of Qatari and 3% of Middle East/North African subjects (with no reported neurocysticercosis) (p<0.001). Cerebrovascular and neurodegenerative etiologies were the most prominent in Qataris, accounting for 14% (p=0.005) and 4% (p=0.03) of cases, respectively. The choice of antiepileptic drugs varied also according to the regional background, but the seizure freedom rate did not, averaging at 54% on the last clinic visit.

SIGNIFICANCE

To our knowledge, this is the first detailed information about epilepsy in Qatar. The geographical origin of patients adds to the heterogeneity of this disorder. Neurocysticercosis should be in the etiological differential diagnosis of epilepsy in patients coming from Southeast Asian countries, despite the fact that it is not endemic to Qatar. The choice of antiepileptic drugs is influenced by the availability of individual agents in the patients' native countries but had no bearing on the final seizure outcome.

Antiepileptic drug therapy and recommendations for withdrawal in patients with seizures and epilepsy due to neurocysticercosis

INTRODUCTION

Neurocysticercosis (NCC) is a leading causes of secondary epilepsy worldwide. There is increasing evidence on the epileptogenic role of NCC, and the presence of edema, calcified scars, gliosis and hippocampal sclerosis support this phenomenon.

AREAS COVERED

We summarized principles of antiepileptic drug (AED) therapy as well as risk factors associated with seizure recurrence after AED withdrawal in patients with NCC. Expert commentary: First-line AED monotherapy is effective as a standard approach to control seizures in most NCC patients. Risks and benefits of AED withdrawal have not been systematically studied, and this decision must be individualized. However, a seizure-free period of at least two years seem prudent before attempting withdrawal. Risk factors for seizure recurrence after AED withdrawal include a history of status epilepticus, poor seizure control during treatment, neuroimaging evidence of perilesional gliosis, hippocampal sclerosis and calcified lesions, as well as persistence of paroxysmal activity in the EEG.

Chromosome loci vary by juvenile myoclonic epilepsy subsyndromes: linkage and haplotype analysis applied to epilepsy and EEG 3.5-6.0 Hz polyspike waves

Juvenile myoclonic epilepsy (JME), the most common genetic epilepsy, remains enigmatic because it is considered one disease instead of several diseases. We ascertained three large multigenerational/multiplex JME pedigrees from Honduras with differing JME subsyndromes, including Childhood Absence Epilepsy evolving to JME (CAE/JME; pedigree 1), JME with adolescent onset pyknoleptic absence (JME/pA; pedigree 2), and classic JME (cJME; pedigree 3). All phenotypes were validated, including symptomatic persons with various epilepsies, asymptomatic persons with EEG 3.5-6.0 Hz polyspike waves, and asymptomatic persons with normal EEGs. Two-point parametric linkage analyses were performed with 5185 single-nucleotide polymorphisms on individual pedigrees and pooled pedigrees using four diagnostic models based on epilepsy/EEG diagnoses. Haplotype analyses of the entire genome were also performed for each individual. In pedigree 1, haplotyping identified a 34 cM region in 2q21.2-q31.1 cosegregating with all affected members, an area close to 2q14.3 identified by linkage (Z max = 1.77; pedigree 1). In pedigree 2, linkage and haplotyping identified a 44 cM cosegregating region in 13q13.3-q31.2 (Z max = 3.50 at 13q31.1; pooled pedigrees). In pedigree 3, haplotyping identified a 6 cM cosegregating region in 17q12. Possible cosegregation was also identified in 13q14.2 and 1q32 in pedigree 3, although this could not be definitively confirmed due to the presence of uninformative markers in key individuals. Differing chromosome regions identified in specific JME subsyndromes may contain separate JME disease-causing genes, favoring the concept of JME as several distinct diseases. Whole-exome sequencing will likely identify a CAE/JME gene in 2q21.2-2q31.1, a JME/pA gene in 13q13.3-q31.2, and a cJME gene in 17q12.

Imaging and Serological-Evidence of Neurocysticercosis Among Patients with Seizures in Odisha, an Unexplored Eastern Coastal Province in India

INTRODUCTION

Neurocysticercosis being a potential to human transmitted disease, is the major cause of seizures and a public health problem in tropical countries. Though India is known to be highly endemic, there are many provinces where reports are still unavailable thereby underestimating its actual burden.

MATERIALS AND METHODS

Anti-Cysticercus IgG antibodies in sera from cases presenting with seizures were screened by ELISA in a preliminary study in Odisha state which is a province in Eastern coastal India that was never explored before. Patients presenting with recent onset of seizures within age group 5 to 50 years, either local residents of Odisha or inhabitants from other parts of the country living for at least one year period in the study area were included.

RESULTS

The present study showed 43.75% cases with seizures to be confirmed neurocysticercosis (NCC) based on serology and brain imaging. However, statistically no association was established between anti-Cysticercus antibody detection and radio imaging characteristics (location, number of lesions, and stage).

CONCLUSION

This is the first study in Odisha presenting a series of cases with serological evidence of exposure to the parasite along with imaging characteristics which was consistent with NCC. It is recommended that NCC must be considered for a differential diagnosis in each active epilepsy case irrespective of prior prevalence information in all unexplored provinces in India and other endemic regions; also a compulsory reporting is warranted in order to aid in quantifying its actual burden.

Neurocysticercosis: an update

Neurocysticercosis (NCC) is the most common helminthic disease of the nervous system in humans and a major cause of acquired epilepsy worldwide. The presentation of the disease is dependent on both the immunological response of the host against the parasite as well as the location of the encysted organisms within the central nervous system (CNS). The principles of management utilized for intraparenchymal disease cannot be applied to extraparenchymal NCC. An advance in management of intraparenchymal NCC, the most common form encountered by physicians, is the use of both albendazole and praziquantel as a treatment strategy. Patients with subarachnoid NCC (SANCC) require months of treatment with both an antiparasitic agent and steroids to avoid complications such as hydrocephalus and vascular events during treatment. The determinants of successful treatment in SANCC have not been established, but response to therapy can be determined by evaluating several endpoints related to disease evolution including radiographic changes, serum antigen, and CSF antigen. Intraventricular NCC is primarily a surgical disease and data supports minimally invasive endoscopic removal of cysts in many of these patients. NCC is increasingly recognized in non-endemic countries due to increased immigration making it important for physicians to become familiar with the management of this disease.

Neurocysticercosis

Neurocysticercosis, the most common helminthic infection of the nervous system, is a major cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of the tapeworm Taenia solium after ingesting its eggs by contagion from an asymptomatic Taenia carrier. Within the nervous system, parasites may locate in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing several pathological changes that are responsible for the clinical pleomorphism of the disease. Seizures are the most common clinical manifestation, but a sizable proportion of patients develop focal deficits, intracranial hypertension, or cognitive decline. Preoperative diagnosis of neurocysticercosis is possible after proper integration of data from neuroimaging studies and immunological tests. Cysticidal drugs (albendazole and praziquantel) have changed the prognosis of most patients with neurocysticercosis. The use of these drugs has shown to reduce the parasite load within the central nervous system and to improve the clinical prognosis of the disease in many cases. Future studies should focus on disease eradication through the implementation of control programs against all the interrelated steps in the life cycle of T solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Anticonvulsant profiles of certain new 6-aryl-9-substituted-6,9-diazaspiro-[4.5]decane-8,10-diones and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones

Synthesis and anticonvulsant potential of certain new 6-aryl-9-substituted-6,9-diazaspiro[4.5]decane-8,10-diones (6a–l) and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones (6m–x) are reported. The intermediates 1-[(aryl)(cyanomethyl)amino]cycloalkanecarboxamides (3a–f) were prepared via adopting Strecker synthesis on the proper cycloalkanone followed by partial hydrolysis of the obtained nitrile functionality and subsequent N-cyanomethylation. Compounds 3a–f were subjected to complete nitrile hydrolysis to give the respective carboxylic acid derivatives 4a–f which were cyclized under mild conditions to give the spiro compounds 5a–f. Ultimately, compounds 5a–f were alkylated or aralkylated to give the target compounds 6a–i and 6m–u. On the other hand, compounds 6j–l and 6v–x were synthesized from the intermediates 5a–f through alkylation, dehydration and finally tetrazole ring formation. Anticonvulsant screening of the target compounds 6a–x revealed that compound 6g showed an ED₅₀ of 0.0043 mmol/kg in the scPTZ screen, being about 14 and 214 fold more potent than the reference drugs, Phenobarbital (ED₅₀ = 0.06 mmol/kg) and Ethosuximide (ED₅₀ = 0.92 mmol/kg), respectively. Compound 6e exhibited an ED₅₀ of 0.019 mmol/kg, being about 1.8 fold more potent than that of the reference drug, Diphenylhydantoin (ED₅₀ = 0.034 mmol/kg) in the MES screen. Interestingly, all the test compounds 6a–x did not show any minimal motor impairment at the maximum administered dose in the neurotoxicity screen.

Gender-related protection from or vulnerability to severe CNS diseases: gonado-structural and/or gonado-activational? A meta-analysis of relevant epidemiological studies

BACKGROUND

A vast scientific literature has dealt with gender-specific risk for brain disorder. That field is evolving toward a consensus to the effect that the estrogen hormone family is outstandingly and uniquely neuroprotective. However, the epidemiology relevant to this general outlook remains piecemeal.

METHOD

The present investigation strategically formats the relevant epidemiological findings around the world in order to quantitatively meta-analyze gender ratio of risk for a variety of relevant severe central nervous system (CNS) diseases at all three gonadal stages of the life cycle, pre pubertal, post adolescent/pre menopausal, and post menopausal.

RESULTS

The data quantitatively establish that (1) no single epidemiological study should be cited as evidence of gender-specific neuroprotection against the most common severe CNS diseases because the gender-specific risk ratios are contradictory from one study to the other; (2) risk for severe CNS disease is indeed significantly gender-specific, but either gender can be protected: it depends on the disease, not at all on the age bracket.

CONCLUSION

Our assay of gender-specific risk for severe brain disease around the world has not been able to support the idea according to which any one gender-prevalent gonadal steroid hormone dominates as a neuroprotective agent at natural concentrations.

Prevalence and risk factors of epilepsy among school children in Kayseri City Center, an urban area in Central Anatolia, Turkey

PURPOSE

To investigate the prevalence of epilepsy in schoolchildren aged 7-17 in the province of Kayseri together with the accompanying risk factors.

METHODS

Ten thousand individuals selected using the "stratified cluster sampling method" from a total population of 259,428 students within the borders of Kayseri city center constituted the study sample. A questionnaire was prepared in line with the epidemiological studies protocol recommended by the International Epilepsy Union Epidemiology and Prognosis Committee in 1993. Data were analyzed on IBM SPSS Statistics 20. Significance was set at p<0.05.

RESULTS

Of the 15,000 questionnaires distributed, 72% (n=10,742) were returned fully completed. Eighty-three students had been or were still being monitored with a diagnosis of epilepsy. The raw prevalence of epilepsy was 6/1000 in females, 9/1000 in males and 8/1000 in both groups together. Prevalence of active epilepsy was 4/1000 in females, 7/1000 in males and 6/1000 in both groups together. Premature birth increased the risk of epilepsy 2.6 times, and average and poor family income levels increased the risk of epilepsy 3.3 and 1.6 times, respectively. A history of febrile convulsion increased the risk of epilepsy 15.1 times.

CONCLUSION

The prevalence of epilepsy in the 7-17 age group in Kayseri is closer to that in developed rather than developing countries. We conclude that the risk factors for epilepsy, and particularly febrile convulsion, and the true prevalence rates need to be determined through studies involving wide socioeconomic strata.

Neurocysticercosis as a cause of epilepsy and seizures in two community-based studies in a cysticercosis-endemic region in Peru

Background

The prevalence of epilepsy added to inadequate treatment results in chronic morbidity and considerable mortality in poor populations. Neurocysticercosis (NCC), a helminthic disease of the central nervous system, is a leading cause of seizures and epilepsy in most of the world.

Methods

Taking advantage of a cysticercosis elimination program, we performed two community-based cross-sectional studies between 2006 and 2007 in 58 rural communities (population 20,610) to assess the prevalence and characteristics of epilepsy and epileptic seizures in this endemic region. Serological and computed tomography (CT) data in individuals with epilepsy were compared to previous surveys in general population from the same region.

Principal findings

In two surveys, 17,450 individuals were evaluated. Lifetime prevalence of epilepsy was 17.25/1000, and prevalence of active epilepsy was 10.8/1000 inhabitants. The prevalence of epilepsy increased after age 25 years and dropped after age 45. Only 24% (45/188) of patients with active epilepsy were taking antiepileptic drugs, all at sub-therapeutic doses. Antibodies to cysticercosis were found in approximately 40% of individuals with epilepsy in both studies. In one survey only individuals presenting strong antibody reactions were significantly associated with having epilepsy (OR 5.74; p<0.001). In the second, the seroprevalence as well as the proportion presenting strong antibody reactions were both significantly higher in individuals with epilepsy (OR 2.2 and 4.33, respectively). Brain CT showed NCC-compatible images in 109/282 individuals with epilepsy (39%). All individuals with viable parasites on CT were seropositive.

Conclusion

The prevalence of epilepsy in this cysticercosis endemic region is high and NCC is an important contributor to it.

Epilepsy is a chronic disease affecting more than 50 million people around the world. In many countries neurocysticercosis (NCC), a parasitic disease of the central nervous system, is a frequent cause of seizures and epilepsy. After a human ingests poorly cooked pork with cysts of the tapeworm Taenia solium, the larvae develops in the small intestine as an adult tapeworm. The tapeworm carrier becomes a source of infective eggs which are released with the stools and can infect humans or pigs with the larval stage, causing cysticercosis. There are many forms of clinical manifestations of NCC; epilepsy is one of them and the most frequent. Scarce population based-studies to identify individuals with epilepsy in rural communities exist, including only a few from Latin America. Our community-based study used a validated survey applied by trained non-medical professionals (nurse, nurse technicians, mid-wife, etc.) and found 301 individuals with epilepsy (17.25/1000), 70% of them without antiepileptic medication and 39% of them with images suggestive of NCC. The prevalence of epilepsy is high in this region and cysticercosis is a frequent finding in individuals with epilepsy.

Adenosine receptors and epilepsy: current evidence and future potential

Adenosine receptors are a powerful therapeutic target for regulating epileptic seizures. As a homeostatic bioenergetic network regulator, adenosine is perfectly suited to establish or restore an ongoing balance between excitation and inhibition, and its anticonvulsant efficacy is well established. There is evidence for the involvement of multiple adenosine receptor subtypes in epilepsy, but in particular the adenosine A1 receptor subtype can powerfully and bidirectionally regulate seizure activity. Mechanisms that regulate adenosine itself are increasingly appreciated as targets to thus influence receptor activity and seizure propensity. Taken together, established evidence for the powerful potential of adenosine-based epilepsy therapies and new strategies to influence receptor activity can combine to capitalize on this endogenous homeostatic neuromodulator.

Neurocysticercosis

Known as a disease of swine in ancient civilizations, cysticercosis is currently considered the most common helminthic infection of the nervous system, and a leading cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of the tapeworm Taenia solium by ingesting its eggs from contaminated food or, most often, directly from a Taenia carrier by the fecal-oral route. Once in the human intestine, Taenia eggs evolve to oncospheres that, in turn, cross the intestinal wall and lodge in human tissues - especially the nervous system - where cysticerci develop. The brain is a hostile environment in which parasites attempt to escape the immune surveillance while the host is trying to drive out the infection. In some cases, cysticerci are destroyed by this immunological attack, while in others, parasites may live unchanged for years. Cysticerci may be located in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing a myriad of pathologic changes that are the main changes responsible for the clinical pleomorphism of neurocysticercosis. Seizures are the most common clinical manifestation of the disease, but some patients present with focal deficits, intracranial hypertension, or cognitive decline. With the exception of cystic lesions showing the scolex as an eccentric nodule, neuroimaging findings of neurocysticercosis are nonspecific and may be seen in other diseases of the nervous system. Likewise, immune diagnostic tests have been faced with problems related to poor sensitivity or specificity. Accurate diagnosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunologic tests, in a proper epidemiologic scenario. The introduction of cysticidal drugs has changed the prognosis of neurocysticercosis. Praziquantel and albendazole have been shown to reduce the burden of infection in the brain (as seen on neuroimaging studies) and to improve the clinical course of the disease in most patients. Further efforts should be directed towards eradicating this disease through the implementation of control programs for all the interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Epilepsy and neurocysticercosis in Latin America: a systematic review and meta-analysis

Background

The difference in epilepsy burden existing among populations in tropical regions has been attributed to many factors, including the distribution of infectious diseases with neurologic sequels. To define the burden of epilepsy in Latin American Countries (LAC) and to investigate the strength of association with neurocysticercosis (NCC), considered one of the leading causes of epilepsy, we performed a systematic review and meta-analysis of the literature.

Methodology

Studies published until 2012 were selected applying predefined inclusion criteria. Lifetime epilepsy (LTE) prevalence, active epilepsy (AE) prevalence, incidence, mortality, treatment gap (TG) and NCC proportion among people with epilepsy (PWE) were extracted. Median values were obtained for each estimate using random effects meta-analysis. The impact of NCC prevalence on epilepsy estimates was determined using meta-regression models. To assess the association between NCC and epilepsy, a further meta-analysis was performed on case-control studies.

Principal findings

The median LTE prevalence was 15.8/1,000 (95% CI 13.5–18.3), the median AE prevalence was 10.7/1,000 (95% CI 8.4–13.2), the median incidence was 138.2/100,000 (95% CI 83.6–206.4), the overall standardized mortality ratio was 1.4 (95% CI 0.01–6.1) and the overall estimated TG was 60.6% (95% CI 45.3–74.9). The median NCC proportion among PWE was 32.3% (95% CI 26.0–39.0). Higher TG and NCC estimates were associated with higher epilepsy prevalence. The association between NCC and epilepsy was significant (p<0.001) with a common odds ratio of 2.8 (95% CI 1.9–4.0).

Significance

A high burden of epilepsy and of NCC in LAC and a consistent association between these two diseases were pointed out. Furthermore, NCC prevalence and TG were identified as important factors influencing epilepsy prevalence to be considered in prevention and intervention strategies.

Epilepsy affects approximately 70 million people worldwide and at least five million people in Latin America. Many researchers have pointed out a different distribution of epilepsy in Latin American countries, with some regions presenting higher frequencies and others presenting lower frequencies. This difference in epilepsy distribution has been attributed to many factors, mainly related to the allocation of health resources and to the presence of environmental and infectious risk factors. Among the latter stands neurocysticercosis, a parasitic disease that has been recognized as the leading cause of acquired epilepsy in the developing world, with a particularly elevated distribution in rural settings. In this study, we performed a statistical analysis to investigate whether neurocysticercosis distribution affects epilepsy distribution among Latin American countries and the relationship between these two conditions. The combined results of the studies included indicated that neurocysticercosis influences epilepsy frequency in Latin America, as countries with higher epilepsy distribution presented also higher neurocysticercosis frequency. Moreover, another analysis pointed out an association between the two diseases. These results appear very important considering that parasitic infections are modifiable factors and that their reduction may contribute to decrease epilepsy burden worldwide.