Fast Facts: Epilepsy in Adults

By P. Tittensor, S. Shepley and M.J. Brodie

Epilepsy is the most common serious neurological condition in the world; however, it is not a homogeneous disease. While some epilepsies spontaneously remit, some are lifelong and others have a variable prognosis. With a growing array of targeted therapies, specific syndromes need to be identified and characterized so appropriate treatment can be given. For others, there are surgical options, and over the last few years, significant advances have been made in neurostimulation. This resource focuses on the management of epilepsy in adults; its sister publication, Fast Facts: Epilepsy in Children and Adolescents', on the treatment of children and adolescents. The authors have provided a succinct and practical resource that will help clinicians investigate, diagnose and treat adults with a wide variety of seizure disorders; it will also help people with epilepsy better understand and manage their condition. Table of Contents: • Epidemiology and prognosis • Classification and causes of seizures, epilepsy types and syndromes • Diagnosis • Pharmacological management • Antiseizure medications • Non-pharmacological management • Status epilepticus and seizure clusters • Specific populations • Comorbidities, quality of life and education • Psychogenic non-epileptic seizures • Research directions

• Language: English
• Publisher: S. Karger
• Release date: Nov 3, 2022
• ISBN: 9783318071948

Book preview

Introduction

Epilepsy is the most common serious neurological condition in the world. However, as it is not a homogeneous disease, it is preferable to use the term ‘epilepsies’, as this better describes a grouping of conditions that share a propensity for an individual to experience sudden unprovoked seizures because of abnormal electrical activity within the brain. While some epilepsies spontaneously remit, some are lifelong and others have a variable prognosis. Complicating the picture are seizures that superficially look like epilepsy but have a psychological cause (psychogenic non-epileptic seizures).

Seizures can affect people of all ages and ethnic backgrounds. They can be dangerous, with sudden unexpected death in epilepsy (SUDEP) occurring in 1 in 1000 people with epilepsy; perhaps as many as 1 in 100 with medically intractable seizures. Psychiatric and other comorbidities are common, and seizures are much more likely to occur in people with intellectual disability, where there can be a complex interplay between epilepsy, treatment and behavior.

With a growing array of targeted therapies, specific syndromes need to be identified and characterized so that these treatments can be offered to individuals who may derive benefit from them. Despite this, the proportion of people with seizures resistant to antiseizure medication (ASM) remains stubbornly static at around 30%. It is yet to be seen whether the latest ASM can have a significant effect on this figure. Surgical options exist for some people, and there have been significant advances in neurostimulation techniques over the last few years, including novel devices and new algorithms for vagus nerve stimulation.

In this resource, we focus on the management of epilepsy in adults. Its sister publication Fast Facts: Epilepsy in Children and Adolescents is also available, together with an online learning program. We hope to have produced a book that is accessible for both healthcare professionals and people with epilepsy. The aim is to provide a succinct and practical resource that will help clinicians investigate, diagnose and treat adults with a wide variety of seizure disorders and also to help people with epilepsy better understand and manage their condition.

1Epidemiology and prognosis

Incidence and prevalence

Epilepsy is the most common serious neurological condition. It affects nearly 50 million people of all ages worldwide.¹ The pooled results of a systematic review and meta-analysis in 2020 showed the overall incidence of epilepsy worldwide to be 61.4 per 100 000 person-years. The incidence was higher in low- and middle-income countries than in high-income countries (139 versus 48.9 per 100 000 person-years, respectively), with greater exposure to perinatal risk factors and higher rates of CNS infections and traumatic brain injury thought to explain the differences.²

A correlation exists between the prevalence of epilepsy and certain measures of socioeconomic deprivation, notably income, employment, and health deprivation and disability. For example, the population prevalence of epilepsy in England ranges from around 4.3 per 1000 in certain counties of the wealthier south-east to 11.6 per 1000 in the socioeconomically deprived north-west town of Blackpool.³ In the USA, studies show racial and economic disparities exist in epilepsy diagnosis, treatment and overall care.⁴ Differences in access to healthcare are likely to be one explanation for these disparities.

Incidence varies greatly with age, with high rates in early childhood, low levels in early adult life and a second peak in people aged over 65 years (Figure 1.1).⁵ In recent years, there has been a fall in the number of children affected as well as a sharp rise in epilepsy in the elderly. Indeed, old age has now become the most common time in life to develop the condition.

Prognosis

The epilepsies are a heterogeneous group of conditions. Prognosis depends on the underlying cause and syndromic diagnosis, but most people will have a good prognosis. In many people – particularly children – the condition will remit, although a substantial proportion will have epilepsy all their lives.

Overall, 60–70% of people with epilepsy become seizure free after treatment with antiseizure medication (ASM),⁶ and some individuals can remain in remission after subsequent drug withdrawal, implying that the epileptogenic causes have truly remitted. The other 30–40% continue to have seizures with varying degrees of frequency and severity.

Figure 1.1 Incidence of single unprovoked seizures, epilepsy and all unprovoked seizures in Iceland between December 1995 and February 1999. Age-specific incidence of all unprovoked seizures was highest in the first year of life (130 per 100 000 person-years) and in those over 65 years old (110.5 per 100 000 person-years). Reproduced from Olafsson et al. 2005, with permission from Elsevier.⁵

Some people become – and remain – seizure free on initiation of the first ASM, while in others the disorder may follow a more ‘remitting–relapsing’ course, fluctuating between periods of seizure freedom and recurrence. A good example of this is temporal lobe epilepsy due to mesial temporal sclerosis, where patients often achieve seizure freedom following initiation of ASM, but relapse months to years later, with a poor response to additional medication.⁷

Factors that indicate a poor prognosis for seizure control include:

•poor response to the initial ASM

•symptomatic causes

•high seizure frequency before ASM

•generalized tonic–clonic seizures (GTCS)

•generalized epileptiform activity on the electroencephalogram (EEG)

•family history of epilepsy

•comorbid psychiatric history.

Mortality

Sudden unexpected death in epilepsy. As long ago as 1854, Delasiauve recognized that people with epilepsy could die suddenly. However, the first definition of sudden unexpected death in epilepsy (SUDEP) was not made until 1997. This was further refined in 2011, incorporating a classification system to establish the likelihood of a fatality being due to SUDEP (Table 1.1).⁸ A large Swedish population-based study used these criteria to establish that the incidence of definite/probable SUDEP was 1.2 per 1000 person-years.⁹

TABLE 1.1

Unified SUDEP definition and classification

Table 1.2 shows the main risk factors for SUDEP. GTCS, with or without focal onset, is the biggest single risk factor. The presence of multiple risks increases mortality exponentially. For example, having at least one GTCS in the previous year and not sharing a bedroom with someone confers a 67-fold increased risk of SUDEP compared with not having a GTCS and sharing a bedroom.¹⁰ Less relevant risks include generalized epilepsies (no significant difference compared with focal epilepsies when GTCS are removed), educational level and mental health disorders.

Women with epilepsy who are pregnant (or have recently given birth) are also vulnerable to SUDEP, with the UK’s MBRRACE national enquiry flagging a doubling of SUDEP deaths among this group in 2016–2018.¹¹

Other causes of death in people with epilepsy. People with epilepsy have a much higher risk of accidents, drowning, burns, aspiration, pneumonia, status epilepticus (SE) and suicide than the general population. Many risk factors associated with epilepsy mortality are known to be modifiable,¹² and communicating these risks to people with epilepsy has been shown to help with risk reduction.¹³,¹⁴ Previous research suggested 42% of epilepsy deaths could be potentially avoidable¹⁵ while more recent studies suggest this figure could be significantly higher (up to 80% preventable).¹⁶ Not taking steps to address epilepsy mortality risks can lead to premature deaths in people who are often young and otherwise healthy.

TABLE 1.2

Risk factors for SUDEP

It is particularly noteworthy that in the UK between 2018 and 2020, the Learning Disabilities Mortality Review (LeDeR) Programme reported epilepsy as one of the most frequently recorded avoidable medical causes of deaths among adults with intellectual disability (ID).¹⁷

Socioeconomic costs

Epilepsy carries a significant socioeconomic burden. In a large cohort study in Denmark, 10 000 of 40 000 people with diagnosed epilepsy were compared with 23 000 controls.¹⁸ People with epilepsy tended to have a lower level of education, be less likely to be married (and have a higher incidence of divorce) and consequently be more likely to live alone. This is significant when considering the risk factors discussed above. In addition, people with epilepsy were more likely to be unemployed, receive disability benefits and, even if in employment, have a lower income than controls.

Epilepsy also confers a significant cost to healthcare systems. A European study published in 2014 estimated that the direct mean annual epilepsy-related costs of a patient with drug-resistant epilepsy was €4485, compared with €1926 for patients with drug-responsive epilepsy.¹⁹ The additional costs were divided between ASM, additional tests and, most significantly, increased hospitalization. The overall direct cost of focal epilepsy in adults was estimated at €3850 per patient per year.

Key points – epidemiology and prognosis

•A systematic review and meta-analysis found an overall global incidence of epilepsy of 61.4 per 100 000 person-years, with higher incidence in low- and middle-income countries.

•The incidence of epilepsy peaks in early childhood and again in people aged over 65 years; older age is now the most common time of life to develop the condition.

•Most people with epilepsy will have a good prognosis.

•GTCS, with or without focal onset, is the biggest single risk factor for SUDEP.

•The socioeconomic cost of epilepsy is significant, affecting both individuals with epilepsy and healthcare systems.

References

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2.Beghi E. The epidemiology of epilepsy. Neuroepidemiology 2020;54:185–91.

3.Steer S, Pickrell, WO, Kerr MP, Thomas RH. Epilepsy prevalence and socioeconomic deprivation in England. Epilepsia 2014;55:1634–41.

4.Blank LJ. Socioeconomic disparities in epilepsy care. Curr Opin Neurol 2022;35:169–74.

5.Olafsson E, Ludvigsson P, Hesdorffer D et al. Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study. Lancet Neurol 2005;4:627–34.

6.Kwan P, Brodie MJ. Early identification of refractory epilepsy. N Engl J Med 2000;342:314–19.

7.Berg AT. The natural history of mesial temporal lobe epilepsy. Curr Opin Neurol 2008;21:173–8.

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9.Sveinsson O, Andersson T, Carlasson S, Tomson T. The incidence of SUDEP. A nationwide population-based cohort study. Neurology 2017;89:170–7.

10.Sveinsson O, Andersson T, Mattsson P et al. Clinical risk factors in SUDEP. A nationwide population-based case-control study. Neurology 2020;94:e419–29.

11.Knight M, Bunch K, Tuffnell D et al., on behalf of MBRRACE-UK. Saving Lives, Improving Mothers’ Care. Lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2016–18. Healthcare Quality Improvement Partnership and National Perinatal Epidemiology Unit, University of Oxford, 2020. www.npeu.ox.ac.uk/assets/downloads/mbrrace-uk/reports/maternal-report-2020/MBRRACE-UK_Maternal_Report_Dec_2020_v10_ONLINE_VERSION_1404.pdf, last accessed 20 April 2022.

12.McCabe J, McLean B, Henley W et al. Sudden unexpected death in epilepsy (SUDEP) and seizure safety: modifiable and non-modifiable risk factors differences between primary and secondary care. Epilepsy Behav 2021;115:107637.

13.Smart C, Page G, Shankar R, Newman C. Keep safe: the when, why and how of epilepsy risk communication. Seizure 2020;78:136–49.

14.Shankar R, Henley W, Boland C et al. Decreasing the risk of sudden unexpected death in epilepsy: structured communication of risk factors for premature mortality in people with epilepsy. Eur J Neurol 2018;25:1121–7.

15.Hanna NJ, Black M, Sander JW et al. National Sentinel Clinical Audit of Epilepsy-Related Death. Report 2002. Epilepsy Bereaved, 2002. www.sudep.org/sites/default/files/nationalsentinelreport1.pdf, last accessed 20 April 2022.

16.Mbizvo GK Schnier C, Simpson CR, Chin RFM. A national study of epilepsy-related deaths in Scotland: trends,