Increasing Trends in the Incidence and Prevalence of Epilepsy in Korea

Increased risk of epilepsy after transient global amnesia: A population-based study in South Korea

PURPOSE

This study aimed to investigate the risk of epilepsy after transient global amnesia (TGA).

METHODS

Study population was recruited using the International Classification of Diseases codes from the Korean National Health Insurance Service database between 2002 and 2020. The incidence of epilepsy was compared between the TGA (n=12,390) and non-TGA (n=33,868) groups, determined using 1:3 propensity score matching. Using Cox proportional hazard regression model, we obtained adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incident epilepsy in the TGA compared with non-TGA group. Logistic regression was performed to examine the independent variables determining incident epilepsy in the TGA group, and adjusted odds ratios (aORs) and 95% CIs were calculated.

RESULTS

The TGA group had a significantly higher cumulative incidence of epilepsy than controls (p <0.001, log-rank test). TGA was significantly associated with incident epilepsy in the Cox model (adjusted HR 1.46, 95% CI 1.36-1.56). The adjusted logistic regression showed that age (per 1 year, aOR 1.02, 95% CI 1.01-1.02), female sex (aOR 0.68, 95% CI 0.60-0.77), hypertension (aOR 1.14, 95% CI 1.00-1.30), diabetes (aOR 1.26, 95% CI 1.10-1.44), stroke (aOR 1.22, 95% CI 1.06-1.40), depression (aOR 1.44, 95% CI 1.22-1.69), anxiety (aOR 1.31, 95% CI 1.14-1.51), alcohol-related disease (aOR 1.96, 95% CI 1.38-2.78), low income (aOR 1.18, 95% CI 1.02-1.36) and rural residence (aOR 1.20, 95% CI 1.02-1.42) were associated with incident epilepsy.

CONCLUSIONS

Our results suggest a longitudinal association of TGA with incident epilepsy.

A Real-World Safety Profile in Neurological, Skin, and Sexual Disorders of Anti-Seizure Medications Using the Pharmacovigilance Database of the Korea Adverse Event Reporting System (KAERS)

(1) Background: The utilization of high-quality evidence regarding the safety of anti-seizure medications (ASMs) is constrained by the absence of standardized reporting. This study aims to examine the safety profile of ASMs using real-world data. (2) Methods: The data were collected from the Korea Adverse Event Reporting System Database (KAERS-DB) between 2012 and 2021. In total, 46,963 adverse drug reaction (ADR)-drug pairs were analyzed. (3) Results: At the system organ class level, the most frequently reported classes for sodium channel blockers (SCBs) were skin (37.9%), neurological (16.7%), and psychiatric disorders (9.7%). For non-SCBs, these were neurological (31.2%), gastrointestinal (22.0%), and psychiatric disorders (18.2%). The most common ADRs induced by SCBs were rash (17.8%), pruritus (8.2%), and dizziness (6.7%). Non-SCBs were associated with dizziness (23.7%), somnolence (13.0%), and nausea (6.3%). Rash, pruritus, and urticaria occurred, on average, two days later with SCBs compared to non-SCBs. Sexual/reproductive disorders were reported at a frequency of 0.23%. SCBs were reported as the cause more frequently than non-SCBs (59.8% vs. 40.2%, Fisher's exact test, p < 0.0001). (4) Conclusions: Based on real-world data, the safety profiles of ASMs were identified. The ADRs induced by SCBs exhibited different patterns when compared to those induced by non-SCBs.

Increased Risk of Dementia after Transient Global Amnesia: A Nationwide Population-Based, Longitudinal Follow-Up Study in South Korea

INTRODUCTION

The long-term cognitive outcomes after transient global amnesia (TGA) have been contradictory in the literature. Our study aimed to longitudinally investigate the association between TGA and incident dementia using long-term data from a nationwide population-based cohort in South Korea.

METHODS

The study population was recruited between 2002 and 2020 using the International Classification of Diseases (Tenth Revision; ICD-10) codes from the Korean National Health Insurance Service database. The cumulative incidence curve was plotted to compare the incidence of dementia between the TGA (ICD-10 code G45.4; n = 10,276) and non-TGA (n = 27,389) groups, determined using 1:3 propensity score matching. Using Cox proportional hazard regression models, we obtained crude and adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the incident dementia in patients with TGA compared to non-TGA controls. To examine independent variables determining dementia in the TGA group, logistic regression analysis was performed, and adjusted odds ratios (aORs) and 95% CIs were calculated.

RESULTS

The TGA group had a significantly higher cumulative incidence of dementia than the non-TGA group (p < 0.001, log-rank test). TGA was significantly associated with incident dementia in the univariate and multivariate Cox models (HR 1.34, 95% CI 1.28-1.39 and aHR 1.40, 95% CI 1.34-1.46, respectively). The adjusted logistic regression for incident dementia in the TGA group showed that age (per 1 year, aOR 1.09, 95% CI 1.09-1.10), female sex (aOR 1.31, 95% CI 1.18-1.45), diabetes (aOR 1.21, 95% CI 1.08-1.35), stroke (aOR 1.30, 95% CI 1.16-1.46), depression (aOR 1.53, 95% CI 1.33-1.76), anxiety (aOR 1.24, 95% CI 1.01-1.39), and rural residence (aOR 1.24, 95% CI 1.10-1.41) were independently associated with incident dementia.

CONCLUSION

Our results suggest a longitudinal association of TGA with incident dementia.

Incidence trends and risk factors for hyponatremia in epilepsy patients: A large-scale real-world data study

OBJECTIVE

This study aimed to evaluate the annual incidence and risk factors of hyponatremia in pediatric, adult, and older adult patients with epilepsy.

METHODS

We enrolled 26,179 patients: 8598 pediatric patients (aged 0-15 years), 16,476 adults (aged 16-64 years), and 1105 older adults (aged ≥65 years). Patients were included if their serum sodium levels were measured between January 2006 and December 2020. Moderate-severe hyponatremia was defined as a serum sodium level of less than 130 mEq/L.

RESULTS

From 2006 to 2020, 677 patients (2.6%) developed moderate-severe hyponatremia. The incidence of hyponatremia per 1000 person-years was 3.1 in the pediatric group, 19.8 in the adult group, and 50.4 in the older adult group. The incidence increased markedly from 36.8 in 2007 to 58.5 in 2020 in the older adult group but remained unchanged in the adult group and tended to decrease in the pediatric group. In the multiple logistic regression model, use of carbamazepine, valproate, phenytoin, phenobarbital, benzodiazepines, and antipsychotics was found to be a significant risk factor for hyponatremia. In adult patients, carbamazepine, benzodiazepine, and antipsychotics induced hyponatremia in a dose-dependent manner. Concomitant use of zonisamide reduced the risk of hyponatremia.

SIGNIFICANCE

Hyponatremia will become an increasingly important concern in clinical settings because the population of epilepsy patients is aging. Serum sodium levels should be monitored carefully when patients are receiving first-generation antiseizure medications or antipsychotics or combinations of these drugs. Our findings may help to minimize the risk of hyponatremia in epilepsy patients.

Anti-seizure medication prescription in epilepsy patients in South Korea: A seven-year population-based retrospective cohort study

BACKGROUND AND OBJECTIVES

This study aimed to explore the natural history of patients with epilepsy using overall antiseizure-medication (ASM) treatment patterns on a nationwide scale in South Korea.

METHODS

We investigated a retrospective longitudinal cohort of patients with epilepsy in South Korea using nationwide data from the Korean National Health Information Database of the Health Insurance and Review Assessment Service between January 1st, 2009, and December 31st, 2018. Histories of each patient's ASM prescription were followed for up to 7 years from the index date, the first observed date of ICD-10 epilepsy diagnosis codes with at least one ASM prescription.

RESULTS

Of 82,390 incident patients analyzed, ten thousand and fifty-nine were followed up to seven years, and nearly 60% of them discontinued the ASM(s). The proportion of patients with possible drug-resistant epilepsy (DRE), who experience three or more types of ASMs, gradually increased, reaching approximately 8.8% of the total number of patients in the seventh year (6.45% for adults, 21.8% for children). The duration of progression for half of the patients with possible DRE was 1.29 years for children, 1.79 years for adults, and 1.62 years for mixed-age patients. However, even in the sixth year, 72 cases progressed to possible DRE, and 6 cases with possible DRE discontinued ASMs in the next year, showing a dynamic process.

DISCUSSION

Our population-based study showed the dynamic changes of anti-seizure medication prescription in epilepsy patients with real-world data, which slowly stabilizes over years after the first diagnosis of epilepsy.

Premature Mortality and Causes of Death Among People With Epilepsy: A Nationwide Population-Based Incident Cohort Study

BACKGROUND AND OBJECTIVES

People with epilepsy (PWE) are at risk of premature death with considerable variability according to the study population. We aimed to estimate the risk and causes of death in PWE according to age, disease severity, disease course, comorbidities, and socioeconomic status in Korea.

METHODS

We conducted a nationwide population-based retrospective cohort study using the National Health Insurance database linked with the national death register. Newly treated PWE from 2008 to 2016 who were identified by antiseizure medication (ASM) prescriptions and diagnostic codes for epilepsy/seizure were included and observed until 2017. We assessed all-cause and cause-specific crude mortality rates and standardized mortality ratios (SMRs).

RESULTS

Among 138,998 PWE, 20,095 deaths were identified, and the mean follow-up period was 4.79 years. The SMR was 2.25 in the overall group of PWE, with a higher value in the younger age group at diagnosis and a shorter time interval after diagnosis. The SMR in the monotherapy group was 1.56, while that in the group with 4 or more ASMs was 4.93. PWE without any comorbidities had an SMR of 1.61. PWE who were rural residents had a higher SMR than those who were urban residents (2.47 vs 2.03, respectively). The causes of death among PWE were cerebrovascular disease (18.9%, SMR 4.50), malignant neoplasms outside the CNS (15.7%, SMR 1.37), malignant neoplasms of the CNS (6.7%, SMR 46.95), pneumonia (6.0%, SMR 2.08), and external causes (7.2%, SMR 2.17), including suicide (2.6%, SMR 2.07). Epilepsy itself and status epilepticus accounted for 1.9% of the overall death. The excess mortality associated with pneumonia and external causes was persistently high, whereas the excess mortality associated with malignancy and cerebrovascular diseases tended to decrease with increasing time since diagnosis.

DISCUSSION

This study showed excess mortality in PWE, even in those without comorbidities and those receiving monotherapy. Regional disparities and sustained risks of deaths from external causes over 10 years imply potential points of intervention. In addition to active control of seizures, education about injury prevention, monitoring for suicidal ideation, and efforts to improve accessibility to epilepsy care are all required to reduce mortality.

Trends of Epilepsy-Related Mortality in South Korea

BACKGROUND AND PURPOSE

Epilepsy increases the risk of death in affected individuals of any age. We aimed to determine the mortality caused by epilepsy and its time trends in Korea.

METHODS

We obtained population and cause of death data between 1993 and 2019 from Statistics Korea. We identified death caused by epilepsy or status epilepticus. We calculated the crude mortality rate (CMR), age-specific mortality rate, age-standardized mortality rate (ASMR, corresponding to epilepsy-related deaths per 100,000 persons in the general population), and the proportional mortality (PM, corresponding to the proportion of epilepsy-related deaths among all-cause deaths).

RESULTS

In 2019, 471 deaths were caused by epilepsy (CMR=0.92), accounting for 0.16% of all deaths in that year. The age-specific mortality rate increased with age, up to 7.01% among individuals aged 80 years and older, while the PM was the highest (3.80%) among individuals aged 5-14 years, which decreased with age. Between 1993 and 2019, the CMR, ASMR, and PM peaked in 2002, and the CMR then rebounded after the trough in this trend in 2011 while the ASMR continued to decrease, and the PM became relatively stable from 2011. Starting in 2005, the age-specific mortality rate for epilepsy had an increasing tendency over time among those aged 75 years or older, and a decreasing tendency in the younger age groups.

CONCLUSIONS

A declining tendency of mortality from epilepsy was found in the overall population of Korea over recent decades. However, epilepsy is a notable cause of death in children, and epilepsy-related mortality is increasing in the elderly population.

Burden of epilepsy in China and its provinces, 1990 to 2019: findings from the Global Burden of Disease Study 2019

BACKGROUND

Epilepsy accounts for a significant portion of the global disease burden. However, little is known about the disease burden of epilepsy in China and its provinces.

METHODS

We assessed the burden of epilepsy in China and its provinces, municipalities, and autonomous regions from 1990 to 2019. Burden was measured as incidence, prevalence, deaths, years lived with disability, years of life lost, and disability-adjusted life years (DALYs), by age, sex, year, and province. We used the Socio-Demographic Index (SDI) to determine the association between the provincial development level and age-standardized DALY rates of epilepsy from 1990 to 2019.

RESULTS

In 2019, epilepsy caused 1367.51 thousand (95% uncertainty interval [UI]: 979.92-1837.61 thousand) DALYs, and the age-standardized DALY rate was 99.77 (95% UI: 71.33-133.52)/100,000. The age-standardized incidence and prevalence rates for epilepsy in China were 24.65/100,000 and 219.69/100,000, increased by 45.00% (95% UI: 8.03-98.74%) and 35.72% (95% UI: 0.47-86.19%) compared with that in 1990, respectively. From 1990 to 2019, the proportion of DALY caused by epilepsy in the age group under 25 years steadily decreased. The proportion of DALYs caused by epilepsy in people aged 50 years and over increased from 9.45% and 10.22% in 1990 to 29.01% and 32.72% for male and female individuals in 2019, respectively. The highest age-standardized mortality rates were seen in Tibet (4.26 [95% UI: 1.43-5.66]/100,000), Qinghai (1.80 [95% UI: 1.15-2.36]/100,000), and Yunnan (1.30 [95% UI: 0.88-1.62]/100,000), and the lowest mortality rates were in Guangdong (0.48 [95% UI: 0.39-0.64]/100,000), Zhejiang (0.56 [95% UI: 0.44-0.70]/100,000), and Shanghai (0.57 [95% UI: 0.41-0.73]/100,000). The age-standardized DALY rates across the country and in provinces, municipalities, and autonomous regions generally decreased as their SDI increased.

CONCLUSIONS

The disease burden of epilepsy is still heavy in China, especially in the western provinces. The incidence and prevalence of epilepsy increased between 1990 and 2019, and the burden of epilepsy in the elderly increases gradually. This study provides evidence on epilepsy prevention and care of different regions in China.

Trends in Prescribing of Antiseizure Medications in South Korea: Real-World Evidence for Treated Patients With Epilepsy

Background and Purpose

We investigated the trends in the prescribing of antiseizure medication (ASM) over a 9-year period, and provide real-world data regarding ASM prescriptions of patients with epilepsy in South Korea.

Methods

This study used data in the Korean National Health Information Database for the period from 2009 to 2017. We included 18 oral ASMs, which were classified into older and newer ASMs based on them first becoming available on the market before or after 1991, respectively. The annual trends in ASM prescriptions were plotted over the 9-year study period, and changes in these trends were evaluated as average annual percentage changes (AAPCs) using Poisson regression. Age- and sex-stratified analyses were also conducted.

Results

Overall, the proportion of prescriptions involving polytherapy with three or more ASMs increased from 10.08% in 2009 to 10.99% in 2017 (AAPC=0.9%, p<0.001) over the 9-year study period. Among monotherapies, although valproate (VPA) was the most frequently prescribed ASM, the prescription rate of levetiracetam (LEV) steadily increased regardless of age and sex over the study period. The monotherapy prescription trends differed depending on age and sex. In the five most frequently used ASM combination regimens, the prescription rates of VPA/LEV, LEV/oxcarbazepine, and LEV/lamotrigine regimens showed increasing tendencies. In contrast, prescription rates for all combined regimens of older ASMs declined over time in all age groups.

Conclusions

This is the first epidemiological study of the changes in prescription trends for ASM in South Korea based on nationwide data from 2009 to 2017. We found progressive increases in the use of newer ASMs for both monotherapy and duotherapy, and for polytherapy with three or more ASMs over the 9-year study period.