epilepsy
Healthcare Service Improvement Team
Primary and secondary prevention of epilepsy
Author:Norma Prosser, Dr Mary Webb, Public Health Specialists
Date:3 September2010 / Version:1
Publication/ Distribution:
- Public (Internet)
Review Date: A review of this document is not planned by Public Health Wales NHS Trust
Purpose and Summary of Document:
This is an evidence-based summary of effective interventions for primary and secondary prevention of epilepsy. The document has been produced to assist local health boards to implement “Designed for People with Chronic Conditions, Service Development Directive, Epilepsy” and should be read in conjunction with that publication.
Primary prevention of epilepsy is difficult because approximately two thirds of people with epilepsy in the UK do not have an anatomically identifiable cause.Interventions are aimed at known risk factors and avoidance measures.
Work Plan reference: HS05
Date:3 Sep 2010 / Version:1 / Page: 1 of 22
Public Health Wales / Primary and secondary prevention of
epilepsy
CONTENTS
1Background
2Epilepsy
2.1Introduction
2.2Search methodology
2.3Prevalence
2.4Hospital admissions
3Primary prevention
3.1Anorexia in newborns/maternal and newborn care
3.2Central nervous system (CNS) infections
3.3Cerebrovascular disease in older adults
3.4Post traumatic brain injury
3.5Alcohol and drug abuse
3.6Depression/mental health disorders
3.7Socioeconomic deprivation
4Secondary prevention
4.1Diagnosis
4.2Management and treatment
4.3Information
4.4Mental illness
4.5Education and employment
5Further information
6References
© 2010 Public Health Wales NHS Trust.
Material contained in this document may be reproduced without prior permission provided it is done so accurately and is not used in a misleading context.
Acknowledgement to Public Health Wales NHS Trust to be stated.
1Background
This document has been produced to assist local health boards to implement the Welsh Assembly Government’s, Designed for people with chronic conditions, Service development directive, Epilepsy1, and should be read in conjunction with that publication.
A key action identified in chapter 2: Prevention – reducing the risks (p.18)of the publication is primary and secondary prevention measures1. This document provides an evidence-based summary of primary and secondary prevention measures.
To supplement the evidence–base, and provide an overview of the topic, information with regard to prevalence (where available); hospital admissions (where information is available from Patient Episode Database Wales - PEDW); and links to additional information resources have been included. The links to the additional information resources is included to indicate where further details, or management and treatment guidance can be sought.
The information contained in this document is not exhaustive.
2Epilepsy
2.1Introduction
Epilepsy is a disorder of the brain characterized by an enduring predisposition to epileptic seizures2, 3. An epileptic seizure is the transient occurrence of signs or symptoms due to abnormal electrical activity in the brain. This manifests itself as a disturbance of consciousness, behaviour, emotion, motor function, or sensation2.
Seizures can vary from the briefest lapses of attention or muscle jerks, to severe and prolonged convulsions i.e. violent and involuntary contractions, or a series of contractions, of the muscles. Seizures can also vary in frequency, from less than one per year to several per day3.
Epilepsy is one of the world's oldest recognized conditions. Fear, misunderstanding, discrimination and social stigma have surrounded epilepsy for centuries. Some of the stigma continues today in many countries and can impact on the quality of life for people with the disorder and their families3.
Epileptic seizures that are not of primary cerebral origin may occur in people who do not have epilepsy if they are exposed to a transient noxious stimulus, such as hypoxia or hypoglycaemia, caused by a disorder originating outside of the brain2.
Epilepsy is not a single condition, there are at least 30different epilepsy syndromes distinguished by their seizure types, age of onset, family history, neurological findings, brain scan results, the electroencephalogram (EEG) pattern and their cause2.
2.2Search methodology
Search terms used: primary prevention, secondary prevention, epilepsy.
Search terms were kept broad to maximise retrieval of literature and search limits set to retrieve papers published between January 2003 to January 2010.
Electronic databases: Medline; Embase; Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effects; Cochrane Central Register of Controlled Trials and British Nursing Index.
Meta search engines: Turning Research Into Practice (TRIP); Google Scholar; SUMsearch.
Websites: NHS Evidence; International Network of Agencies for Health Technology Assessment (INAHTA); National Institute for Health and Clinical Excellence (NICE); National Horizon Scanning Centre and Map of Medicine; UpToDate.
2.3Prevalence
Epilepsy is the most common serious neurological condition with a prevalence of 50-70/10,0004.Approximately 456,000people in the UK have epilepsy, this equates to around 1 in 130people, and a GP on average will care for 15people with epilepsy2.Some 27,000people in the UK are newly diagnosed with epilepsy each year, equivalent to approximately 1 in 20002.
Epilepsy most commonly starts in children, or in people older than 60years of age. The increased incidence in the elderly is caused by acquired conditions that predispose to epilepsy, such as cerebrovascular disease and degenerative conditions.Epilepsy is much more common in people with a learning disability, with prevalence in this group of 1 in 5people2.
Approximately 30% of people with epilepsy have a first-degree relative with the condition. Familial epilepsies offer an opportunity to identify genes associated with epilepsy; a case control study and meta-analysis of the association between temporal lobe epilepsy (TLE) and genetic variants of the prodynorphin promoter gene provide weak evidence of an association between familial TLE and certain allelic variants5.
It is known that people with autism have a higher risk of epilepsy and in a recent systematic review6 autism associated with intellectual disability and/or female gender is shown to carry a significantly higher risk of epilepsy than expected, especially in those with very low IQ. The association between complex autism and epilepsy may reflect common causation and/or the effect of epileptic seizures on the developing brain.
Approximately a third of people with epilepsy in the UK have an anatomically identifiable cause, this is described as symptomatic epilepsy and is the most common cause of epilepsy in older people2. The most common identifiable causes include:
- cerebrovascular disease, in 15% of people;
- cerebral tumour, in 6% of people;
- post-traumatic epilepsy, in 2% of people.
Less common identifiable causes include2:
- perinatal brain injury caused by foetal hypoxia or trauma;
- brain infections, such as meningitis;
- cortical malformation;
- vascular malformation.
The underlying cause in most patients is thought to be complex developmental abnormalities in synaptic connections and neurotransmitter distribution and release2. Epilepsy is a feature of over 200genetic disorders, accounting for approximately 2% of people with epilepsy2.
2.4Hospital admissions
Figure 1: Persons admitted to hospital in Walesin 2008 with a principal diagnosis of epilepsy (ICD-10, G40 & G41)by Unitary Authority
Source: PEDW
Figure 2: Persons admitted to hospital in Walesin 2008 with a principal diagnosis of epilepsy (ICD-10, G40 & G41) by Local Health Board
Source: PEDW
Table 1: Persons admitted to hospital in Walesin2008 with a principal diagnosis of epilepsy (ICD-10, G40 & G41)
Local Health Board / Unitary Authority / AdmissionsBetsiCadwaladrUniversity / Isle of Anglesey / 99
Gwynedd / 159
Conwy / 128
Denbighshire / 93
Flintshire / 107
Wrexham / 104
Powys / Powys / 108
Hywel Dda / Ceredigion / 42
Pembrokeshire / 89
Carmarthenshire / 219
Abertawe Bro Morgannwg / Swansea / 198
Neath Port Talbot / 165
Bridgend / 102
Cardiff and ValeUniversity / Vale of Glamorgan / 113
Cardiff / 258
Cwm Taf / Rhondda Cynon Taff / 158
Merthyr Tydfil / 79
Aneurin Bevan / Caerphilly / 176
Blaenau Gwent / 83
Torfaen / 72
Monmouthshire / 74
Newport / 135
Total / 2761
Source: PEDW
3Primary prevention
Primary prevention of epilepsy is difficult because approximately two thirds of people with epilepsy in the UK do not have an anatomically identifiable cause2.
The Welsh Assembly Governmentservice development directive for epilepsy1 concludes that prevention of underlying causes of epilepsy is most likely for:
- anorexia in newborns;
- central nervous system infections in children;
- cerebrovascular disease in older adults;
- post traumatic brain injury;
- alcohol and drug misuse.
And that there is emerging evidence for:-
- depression;
- socioeconomic disadvantage.
3.1Anorexia in newborns/maternal and newborn care
It is known that adequate nutrition for women planning pregnancy is essential and that epilepsy is associated with low birth weight. National Institute for Health and Clinical Excellence (NICE), Public Health guidance summarises interventions to improve the nutrition of mothers from low income households who are often poorly nourished7.
Proper antenatal and perinatal care to avoid problems during pregnancy and childbirth may lessen complications that could lead to epilepsy. Appropriate antenatal and intrapartum care guidance have been published by NICE8, 9, together with recommendations for prevention of anorexia in newborns in postnatal care10.
3.2Central nervous system (CNS) infections
Effective and timely treatment of meningitis and other CNS infections is essential to minimise the development of epilepsy11, between 5 and 30 per cent of patients with encephalitis or meningitis, and up to 50 per cent of patients with a cerebral abscess, epilepsy occurs.
Appropriate vaccination against certain diseases of childhood and adolescence or young adulthood may decrease the likelihood of infections that can involve the CNS and lead to epilepsy. Current guidelines for vaccines and immunisations are available from the Public Health Wales Health Protection Team11.
3.3Cerebrovascular disease in older adults
Cerebrovascular diseases are the main cause of epilepsy in old age and a first epileptic seizure in a patient over 60 years old is more likely to be due to cerebrovascular disease than to any other etiology.
Population-based epidemiological studies12 have shown that stroke multiplies the risk of an epileptic seizure by a factor of 23, and the risk of epilepsy in the first year after the stroke by a factor of 17, compared to the risk in the comparable general population. Epileptic seizures in the elderly are often not diagnosed and it is recommended that for improved differential diagnosis, long-term electroencephalogram (EEG) and electrocardigram(ECG) recordings should be performed more often12. The pharmacotherapy of elderly patients with antiepileptic drugs is complex, requiring special attention to age-related changes in pharmacokinetics and pharmacodynamics.
NICE and Scottish Intercollegiate Guidelines Network (SIGN)13, 14 guidelines on stroke does not specifically deal with prevention of epilepsy. A large scale study from Canada demonstrated that the presence of seizures after stroke was associated with increased resourceutilisation, length of hospital stay, whilst decreasing both 30 day and 1 year survival15.
Identifying the risk factors for a first epileptic seizure after stroke is important in prevention. A recent case control study investigated the risk factors for epilepsy after stroke, it was found that cortical involvement, the presence of prior lesions on CT-scan, and haemorrhagic lesion are the most important risk factors for a first-ever seizure after stroke16.
There is preliminary evidence that glutamate may prevent seizures in stroke patients17.
3.4Post traumatic brain injury
Traumatic brain injuries are most frequently due to road traffic accidents or falls, and the risk of epilepsy after traumatic brain injury is high. In a recent population based cohort study in Denmark it was found from the records of >1.65 million people studied that the risk of epilepsy was increased 10 years after mild brain injury, severe brain injury and skull fracture18. Relative risk increased with age for mild and severe injury and was particularly high amongst people older than 15 years with mild and severe injury. The authors suggest that the long lasting risk of epilepsy after brain injury provides a window of opportunity for prevention of post-traumatic epilepsy.
The result of a comprehensive review19that evaluated evidence of effectiveness of prophylactic anti-epileptic drugs for the prevention of seizure disorders following acquired brain injurysupport previous findings that prophylactic anti-convulsants reduce seizures in the first week post-injury in adults. However they do not reduce the occurrence of seizures after the first week19.
There are effective ways to reduce the occurrence and severity of motor vehicle and traffic injuries by consistently using seat belts and safety seats for small children, air bags, bicycle helmets and motorcycle helmets.Extensive information on traumatic brain injury and their prevention and safety measures to prevent accidents has been published by the Centers for Disease Prevention in the US20. A Cochrane review21 demonstrates that bicycle helmet legislation appears to be effective in increasing helmet use and decreasing head injury rates in the populations for which it is implemented, but there is not any high quality evidence on outcomes22.
Preventing falls in the elderly is one means of preventing the occurrence of epilepsy amongst this population. However, research into the methods to prevent falls show inconsistent results, and a recent randomised controlled trial (RCT) of amulti-faceted intervention, failed to reduce falls in the elderly23.Another recent systematic review and meta-analyses concluded that exercise interventions do reduce falls in elderly people in the community24.
3.5Alcohol and drug abuse
Seizures can be provoked by abuse from drugs such as heroin, methadone, cocaine, ecstasy, amphetamines and with alcohol abuse. The risk of recurrence of such seizures can be greatly reduced by correction or withdrawal of the substance involved.
Life-time prevalence of epileptic seizures was assessed in 626 consecutive patients treated for substance abuse in which seizures were reported in 8.63% (9.2% in alcohol abusers, 12.5% in opioid abusers) patients25. A total of 64.8% of the seizures were associated with substance use, these occurred during withdrawal in the alcohol cohort and during intoxication with dextropropoxyphene and withdrawal from heroin or poppy husk in the opioid cohort. Results indicate that seizures may be more common in older patients with longer duration of dependence among those abusing alcohol25.
Data from the Nurses Health Study II26 demonstrate that compared with never smoking, current smoking was associated with an increased risk of seizure after adjustment for stroke and other potential confounding factors. Past smoking was not associated with risk of seizure but was associated with modestly increased risk of epilepsy. Long term caffeine and moderate alcohol intake were not associated with seizure or epilepsy.
A meta-analysis of the data on the association between alcohol consumption and epilepsy indicated that there is a strong and consistent association. Most of the relevant studies found that a high percentage of alcohol users with epilepsy would qualify for the criteria of alcohol dependence27.
The National Treatment Agency for Substance Misuse28 has published guidance for the pharmacological management of substance misuse among young people. There is a Welsh Assembly Government strategy to reduce harm from substance misuse29, and further guidance is being considered30.
3.6Depression/mental health disorders
There is a possible association between depression and epilepsy. Research into medical conditions and treatment amongst people with mental health conditions has found that people with schizophrenia or bipolar disease have a higher risk of epilepsy. In a study commissioned by the Disability Rights Commission31it was found that patients are not receiving appropriate screening or treatments for illnesses such as epilepsy. The results of the study suggest that epilepsy is more than twice as frequent amongst people with schizophrenia or bipolar disorder31.
In arecent study32, pre-morbid psychiatric conditions occurred at higher rates in the epilepsy versus non-epilepsy groups:
- depression (17% vs 12%);
- anxiety (12% vs 8%);
- psychosis (12% vs 5%); and
- substance abuse (8% vs 4%).
However, only psychosis (OR=1.4, CI 1.2-1.6) was significantly associated with epilepsy when controlling for neurological disorders and psychiatric conditions (e.g. stroke, dementia, brain tumour, head injury)32.
Patients with dementia are at an increased risk of epilepsy. In a retrospective study of the records of patients identified as having dementia and epilepsy; the results indicated that most patients with the co-morbidity of epilepsy and dementia have complex partial seizures that can be adequately controlled by anti-epileptic drugs33. The long term effect of seizure activity on dementia is unknown.
3.7Socioeconomic deprivation
There is a growing body of evidence linking socioeconomic status as a risk factor for epilepsy in adults. A recent population based study from Swedensuggests that socioeconomic status and occupation sometimes carry significantly increased risks of hospital admission for epilepsy34. A total of 22,638 men and 16,871 women >30 years were hospitalised for epilepsy during the study period. Low education and low income (both men and women) and being an unskilled/skilled worker (only men) was associated with slightly but significantly increased risks. Among men, increased risk was noted for waiters, launderers and dry cleaners, clerical workers, other construction workers, sales agents and drivers. Among women, increased risk was observed among cooks, stewards, administrators and managers34.
A UK based analysis of the causes of social inequality in epilepsy and how to develop a rehabilitation strategy has been published35. The authors report that there is a need for education and support for self management following diagnosis. Missing this opportunity will result in disadvantage to those whose educational level and knowledge of epilepsy are low. Despite the existence of centres of excellence for the diagnosis and management of epilepsy, areas of deprivation have higher than national levels of patients reporting a seizure in the prior year and higher emergency hospital admissions. The authors conclude that specialists working in partnership with general practitioners (GPs) forming primary-secondary networks are likely to be effective in improving the epilepsy outcomes for areas of social deprivation.
4Secondary prevention
Secondary prevention of epilepsy requires:
- timely and accurate diagnosis following suspected epileptic seizures;
- appropriate evidence-based management and treatment;
- provision of high quality information for patients, healthcare professionals and the general public;
- counselling and detection of mental illness;
- sensitive education and employment services.
4.1Diagnosis
Current national guidelines recommend that diagnosis should be made by a neurologist or epilepsy specialist36 or a specialist medical practitioner with training and expertise in epilepsy37. The diagnosis of epilepsy in children should be established by a specialist paediatrician with training and expertise in epilepsy37.
Presentations of suspected epileptic seizure and the assessment requirements when an epileptic seizure is assumed, is outlined in the NHS Clinical Knowledge Summaries2.