SUDEP and other causes of mortality in childhood-onset epilepsy

Childhood-onset epilepsy five decades later. A prospective population-based cohort study

OBJECTIVE

To study the impact of childhood-onset epilepsy on a variety of outcomes across the life span.

METHODS

A population-based cohort of 245 subjects with childhood-onset epilepsy was assessed for outcomes at 45 years. In addition, 51 of 78 surviving subjects with uncomplicated epilepsy and 52 of 99 originally matched controls participated in a detailed evaluation including electroencephalography (EEG), imaging, and laboratory studies at 50 years.

RESULTS

Of 179 surviving subjects, 61% were in terminal 10-year remission and 43% in remission off medications. At 45 years, 95% of the idiopathic group, 72% of the cryptogenic group, and 47% of the remote symptomatic group were in terminal remission (p < 0.001). Abnormal neurologic signs were significantly more common in subjects with uncomplicated epilepsy than in controls. Mortality during period 1992-2012 was higher in subjects than in controls (9% vs. 1%, p = 0.02). The rate of 3T MRI abnormalities was higher in subjects than in controls (risk ratio [RR] 2.0; 1.3-3.1) specifically including findings considered markers of cerebrovascular disease (RR 2.5; 1.04-5.9). Even subjects with idiopathic epilepsy had higher rates of imaging abnormalities than controls (73% vs. 34%, p = 0.002).

SIGNIFICANCE

Long-term seizure outcomes are excellent and a function of etiology. The presence of imaging abnormalities suggestive of vascular disease may put these subjects at higher risk for clinically evident stroke and cognitive changes as they age.

Long-term mortality in children and young adults with epilepsy--A population-based cohort study

PURPOSE

Epilepsy is associated with an increased mortality. This study estimates the effects of co-morbid disorders on short-term and long-term mortality and presents cause-specific mortality for children and young adults with epilepsy.

METHODS

We established a population-based cohort of 1,855,946 children born in Denmark from 1977 to 2006. Children were followed from the 29th day of life until death, emigration or 31 December 2006. Data was retrieved from Danish longitudinal civil service, health and cause of death registries. Overall, 25,244 persons were diagnosed with epilepsy and 10,647 persons died during 26.2 million person years of follow-up. Among those who died, 803 were diagnosed with epilepsy prior to death. Mortality rate ratio (MRR) was estimated by comparing the mortality rate among persons with epilepsy with the mortality rate in persons without epilepsy.

RESULTS

The mortality among children and young adults with epilepsy was almost 15 times increased compared with persons without epilepsy (MRR: 14.9 (95% CI: 13.9-16.1)). After excluding persons with adverse birth outcomes and persons with comorbid neurological disorders (other than epilepsy), the MRR was still more than four times increased (MRR: 4.20 (95% CI: 3.28-5.30)). Short- and long-term MRRs were particularly high for those diagnosed with epilepsy before 5 years of age (short-term mortality (<1 year); MRR: 41.5 (95% CI: 35.4-48.3), long term mortality (≥ 1 year); MRR: 21.6 (95% CI: 19.5-23.8)). The cumulative mortality 20 years after the first epilepsy diagnosis was 7.6% (95% CI: 6.8-8.4%) among males and 5.8% (95% CI: 5.1-6.5%) among females.

Refractory epilepsy in children

Refractory epilepsy, estimated to affect 10-20% children with epilepsy, can have profound effect on the education, social and cognitive functioning and recreational activities of the child. The definitions are still evolving. A detailed clinical evaluation may reveal an accurate syndromic and etiological diagnosis. The recent advances in neuroimaging and electrophysiology have revolutionized the management of children with refractory epilepsy and supplement the clinical evaluation. Genetic and metabolic evaluation may be indicated in selected cases. The rational use of anti-epileptic drugs, epilepsy surgery and dietary therapies are the mainstay in the management. Various experimental treatment options and pharmacogenetics offer hope for future.

Epidemiologic aspects: lost in transition

Population-based studies focusing on the long-term prognosis of childhood-onset epilepsy show that despite seizure remission in 70-80% of cases, cognitive, behavioral and psychosocial complications are common and will require management and monitoring in adulthood. This type of study design also demonstrates that death is rare in children who are intellectually and neurologically normal and followed for many years, which is the same for the general population. Only those children with neurologic problems sufficiently severe to interfere with activities of daily living have an increased risk of death in childhood. Investigation of potentially remediable complications is paramount, and the use of antiepileptic medications with potential adverse cognitive and behavioral effects should be identified and eliminated or reduced. In addition, education of the family should be improved. As well, identification and control of social and psychiatric complications is necessary and implies a comprehensive management of the patient before and after the transition from childhood into adulthood.

The consequences of refractory epilepsy and its treatment

Seizures in some 30% to 40% of patients with epilepsy fail to respond to antiepileptic drugs or other treatments. While much has been made of the risks of new drug therapies, not enough attention has been given to the risks of uncontrolled and progressive epilepsy. This critical review summarizes known risks associated with refractory epilepsy, provides practical clinical recommendations, and indicates areas for future research. Eight international epilepsy experts from Europe, the United States, and South America met on May 4, 2013, to present, review, and discuss relevant concepts, data, and literature on the consequences of refractory epilepsy. While patients with refractory epilepsy represent the minority of the population with epilepsy, they require the overwhelming majority of time, effort, and focus from treating physicians. They also represent the greatest economic and psychosocial burdens. Diagnostic procedures and medical/surgical treatments are not without risks. Overlooked, however, is that these risks are usually smaller than the risks of long-term, uncontrolled seizures. Refractory epilepsy may be progressive, carrying risks of structural damage to the brain and nervous system, comorbidities (osteoporosis, fractures), and increased mortality (from suicide, accidents, sudden unexpected death in epilepsy, pneumonia, vascular disease), as well as psychological (depression, anxiety), educational, social (stigma, driving), and vocational consequences. Adding to this burden is neuropsychiatric impairment caused by underlying epileptogenic processes ("essential comorbidities"), which appears to be independent of the effects of ongoing seizures themselves. Tolerating persistent seizures or chronic medicinal adverse effects has risks and consequences that often outweigh risks of seemingly "more aggressive" treatments. Future research should focus not only on controlling seizures but also on preventing these consequences.

Burden of epilepsy in rural Kenya measured in disability-adjusted life years

OBJECTIVES

The burden of epilepsy, in terms of both morbidity and mortality, is likely to vary depending on the etiology (primary [genetic/unknown] vs. secondary [structural/metabolic]) and with the use of antiepileptic drugs (AEDs). We estimated the disability-adjusted life years (DALYs) and modeled the remission rates of active convulsive epilepsy (ACE) using epidemiologic data collected over the last decade in rural Kilifi, Kenya.

METHODS

We used measures of prevalence, incidence, and mortality to model the remission of epilepsy using disease-modeling software (DisMod II). DALYs were calculated as the sum of Years Lost to Disability (YLD) and Years of Life Lost (YLL) due to premature death using the prevalence approach, with disability weights (DWs) from the 2010 Global Burden of Disease (GBD) study. DALYs were calculated with R statistical software with the associated uncertainty intervals (UIs) computed by bootstrapping.

RESULTS

A total of 1,005 (95% UI 797-1,213) DALYs were lost to ACE, which is 433 (95% UI 393-469) DALYs lost per 100,000 people. Twenty-six percent (113/100,000/year, 95% UI 106-117) of the DALYs were due to YLD and 74% (320/100,000/year, 95% UI 248-416) to YLL. Primary epilepsy accounted for fewer DALYs than secondary epilepsy (98 vs. 334 DALYs per 100,000 people). Those taking AEDs contributed fewer DALYs than those not taking AEDs (167 vs. 266 DALYs per 100,000 people). The proportion of people with ACE in remission per year was estimated at 11.0% in males and 12.0% in females, with highest rates in the 0-5 year age group.

SIGNIFICANCE

The DALYs for ACE are high in rural Kenya, but less than the estimates of 2010 GBD study. Three-fourths of DALYs resulted from secondary epilepsy. Use of AEDs was associated with 40% reduction of DALYs. Improving adherence to AEDs may reduce the burden of epilepsy in this area.