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.

Epilepsy and aging

The intersection of epilepsy and aging has broad, significant implications. Substantial increases in seizures occur both in the elderly population, who are at a higher risk of developing new-onset epilepsy, and in those with chronic epilepsy who become aged. There are notable gaps in our understanding of aging and epilepsy at the basic and practical levels, which have important consequences. We are in the early stages of understanding the complex relationships between epilepsy and other age-related brain diseases such as stroke, dementia, traumatic brain injury (TBI), and cancer. Furthermore, the clinician must recognize that the presentation and treatment of epilepsy in the elderly are different from those of younger populations. Given the developing awareness of the problem and the capabilities of contemporary, multidisciplinary approaches to advance understanding about the biology of aging and epilepsy, it is reasonable to expect that we will unravel some of the intricacies of epilepsy in the elderly; it is also reasonable to expect that these gains will lead to further improvements in our understanding and treatment of epilepsy for all age groups.

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

OBJECTIVE

Epilepsy 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.

METHODS

The 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.

RESULTS

This 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.

CONCLUSIONS

Understanding of the global epilepsy burden has evolved as more regions have been studied. This up-to-date worldwide analysis provides the first estimate of surgical epilepsy volume and an updated comprehensive overview of current epidemiological trends. The disproportionate burden of epilepsy on low- and middle-income countries will require targeted diagnostic and treatment efforts to reduce the global disparities in care and cost. Quantifying global epilepsy provides the first step toward restructuring the allocation of healthcare resources as part of global healthcare system strengthening.

Prevalence of pediatric epilepsy in low-income rural Midwestern counties

Epilepsy is one of the most common disabling neurological disorders, but significant gaps exist in our knowledge about childhood epilepsy in rural populations. The present study assessed the prevalence of pediatric epilepsy in nine low-income rural counties in the Midwestern United States overall and by gender, age, etiology, seizure type, and syndrome. Multiple sources of case identification were used, including medical records, schools, community agencies, and family interviews. The prevalence of active epilepsy was 5.0/1000. Prevalence was 5.1/1000 in males and 5.0/1000 in females. Differences by age group and gender were not statistically significant. Future research should focus on methods of increasing study participation in rural communities, particularly those in which research studies are rare.

Spatial patterns of epilepsy-related emergency department visits in california

Background

Socio-demographic factors are associated with increased emergency department (ED) use among patients with epilepsy. However, there has been limited spatial analysis of such visits.

Design and methods

California ED visit at the patient ZIP Code level were examined using Kulldorf’s spatial scan statistic to identify clusters of increased risk for epilepsy-related visits. Logistic regression was used to examine the relative importance of patient socio-demographics, Census-based and hospital measures.

Results

During 2009-2011 there were 29,715,009 ED visits at 330 hospitals, of which 139,235 (0.5%) had epilepsy (International Classification of Disease-9 345.xx) as the primary diagnosis. Three large urban clusters of high epilepsy-related ED visits were centred in the cities of Los Angeles, Oakland and Stockton and a large rural cluster centred in Kern County. No consistent pattern by age, race/ethnicity, household structure, and income was observed among all clusters. Regression found only the Los Angeles cluster significant after adjusting for other measures.

Conclusions

Geospatial analysis within a large and geographically diverse region identified a cluster within its most populous city having an increased risk of ED visits for epilepsy independent of selected socio-demographic and hospital measures. Additional research is necessary to determine whether elevated rates of ED visits represent increased prevalence of epilepsy or an inequitable system of epilepsy care.

Family history and frontal lobe seizures predict long-term remission in newly diagnosed cryptogenic focal epilepsy

PURPOSE

Cryptogenic focal epilepsy (CFE) is a heterogeneous clinical disorder including patients with severe refractory forms and patients with a fairly good prognosis. Predictors of prognosis in CFE are poorly understood. The aim of this retrospective study is to identify long-term (5-year) prognostic predictors in patients with newly diagnosed CFE.

METHODS

Subjects with cryptogenic focal epilepsy (CFE) seen from April 1987 to September 2011 in two twin Epilepsy Centres located in Reggio Calabria and Catanzaro, Calabria, Southern Italy, were screened. Patients were excluded if they had psychogenic seizures, major psychiatric disorders presence of brain lesions except for non-specific white matter T2-hyperintensities, short follow-up (less than five years) or for having received the diagnosis of CFE elsewhere. One hundred and eighty-six patients, firstly diagnosed in our Centres, constituted the study sample. Survival curves were generated according to the Kaplan-Meier method and compared with the log-rank test. The endpoint was the cumulative time-dependent chance of 5-year remission after treatment start. Independent predictors of remission were tested by multivariate analysis using Cox proportional hazards function models. The accuracy of the resulting model was tested with Receiver Operating Characteristics (ROC) curve analysis.

KEY FINDINGS

The cumulative incidence of remission was 23%. At Kaplan-Meier analysis, the only factor predicting remission was family history of epilepsy or febrile seizures (FS; p=0.02). At Cox regression, family history and frontal lobe epilepsy showed to be independent predictors of outcome (p=0.02 and 0.03, respectively). The accuracy of these predictors was good (area under ROC curve 0.648, 95% CI 0.575-0.716). Interestingly, we also found a considerable (7 years) diagnostic delay that did not result in a worse prognosis.

SIGNIFICANCE

About one quarter of subjects with newly diagnosed CFE attains 5-year seizure remission during follow-up. Family history of epilepsy or FS and frontal localization are independent prognostic predictors.