Most people with epilepsy do not have intellectual disabilities, but a substantial minority of people with intellectual disabilities have epilepsy.
Victor Olotu (UK), Rohit Shankar (UK) and Jane Bernal (UK)
Epilepsy is known to be a potentially disabling, chronic and socially isolating condition. A diagnosis of Epilepsy even now still carries a stigma. The individual and their family can be affected physically, psychologically and socioeconomically. Similarly individuals with Intellectual disability, in broad terms a condition which occurs during the developmental period and leads to deficits in intelligence, overall development and adaptive functioning skills or abilities, and their families and carers, experience a range of physical, social and psychological challenges. Prasher and Kerr1 (2008) suggested that the existence of these 2 condition; epilepsy and intellectual disability, in an individual thus poses unique challenges.
Thus appropriate diagnosis of epilepsy (history, investigations, classification and aetiology) and management are essential to help in reducing the considerable social impact, potentially stigmatisation, secondary handicap and low self-esteem compounded by social exclusion experienced by people with intellectual disabilities.
Seizures occur when there is abnormal excessive electrical discharge from the brain resulting in a sudden disturbed behaviour, emotional, motor or sensory function with or without changes in consciousness. Whilst Epilepsy is the experience of recurrent unprovoked seizures. The International League Against Epilepsy2 (2014) state that Epilepsy is a disease of the brain defined by any of the following conditions:
1. At least two unprovoked (or reflex) seizures occurring greater than 24 hours apart
2. One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years
3. Diagnosis of an epilepsy syndrome
Status epilepticus is a condition where either a prolonged seizure or repeated epileptic seizures occurs lasting for over 30 minutes, without intervening recovered consciousness.
Classification of seizures
Based on a 1989 consensus report by the commission of classification and terminology of the International League Against Epilepsy3, seizures are divided into 2 main types:
1. Partial Seizure - Spontaneous electrical discharges arise from a focal point in the brain. This is divided into Simple Partial Seizures (retained consciousness) and Complex Partial Seizures (altered consciousness) e.g. Temporal Lobe Seizures, Frontal Lobe Seizures, Occipital Lob Seizures and Parietal Lobe Seizures
2. Generalised Seizures - Spontaneous electrical discharges take place on both sides of the brain in a synchronous manner. Consciousness is impaired from the beginning e.g. absence, myoclonic, tonic-clonic, tonic and atonic seizures
There is however a third recognised category
3. Secondary generalised Tonic-Clonic Seizures - These are usually preceded by a partial seizure.
Classification of epilepsy
Similar to the classification of seizures the 1989 consensus report by the Commission on Classification and Terminology of the International League Against Epilepsy3 classifies epilepsy according to the following:
1. The site of seizure onset - generalised or focal.
2. The presumed seizure aetiology -
Epilepsy is often caused by the same brain damage or maldevelopment that caused the intellectual disability. It is much more common in some conditions, particularly Tuberous Sclerosis. In people with Down's syndrome, the onset of epilepsy may form part of the onset of Alzheimer's.
In the adult general population after stroke Epilepsy is the second commonest serious chronic neurological disorder after stroke (Prasher and Kerr 2008)1.
The National Institute for Health and Care Excellence (NICE)4 in 2012 stated that an accurate estimate of incidence and prevalence was difficult because of the difficulty in identifying people who may have epilepsy. Epilepsy has been estimated to affect between 362,000 and 415,000 people in England. In addition, there will be further individuals, estimated to be 5–30%, so amounting to up to another 124,500 people, who have been diagnosed with epilepsy, but in whom the diagnosis is incorrect.
Incidence of epilepsy in developed countries is estimated to be 50 per 100,000 per year (Sander and Shorvon 1996)5 and the prevalence of active epilepsy in the UK is estimated to be 5–10 cases per 1000. Two-thirds of people with active epilepsy have their epilepsy controlled satisfactorily with anti-epileptic drugs (AEDs). Other approaches may include surgery. Optimal management improves health outcomes and can also help to minimise other, often detrimental, impacts on social, educational and employment activity.
Among people known to Intellectual Disability services in the UK prevalence of epilepsy is 20-30% and possibly higher in the residual populations of long-stay institutions (Bell and Sander, 2001)6. Supporting people with poorly controlled epilepsy requires high levels of competence and confidence in staff in community settings.
The prevalence rate of epilepsy amongst people with intellectual disabilities has been reported as at least twenty times higher than for the general population, with seizures commonly multiple and resistant to drug treatment (Amiet et al 20087, Branford et al 19988, Matthews et al 20089). This is especially true in severe and profound Intellectual Disability. Uncontrolled epilepsy can have serious negative consequences on both quality of life and mortality (Kerr et al 200110, 11).
The management of epilepsy is also particularly important because of the risk of sudden expected death in epilepsy (SUDEP). Nashef (1997)12 described SUDEP as being, a sudden, unexplained, witnessed or unwitnessed, non-traumatic and non-drowning death in an individual with epilepsy, with or without evidence for a seizure, and excluding documented status epilepticus, in which post-mortem examination does not reveal a toxicological or anatomic cause for death. Shankar et al (2013)13 described that the incidence of sudden death appears to be 20 times higher in patients with epilepsy compared with the general population, and SUDEP is the most important directly epilepsy-related cause of death. NICE (2012)4 recommends that patient’s, carers and families need to be counselled using information tailored to the patient’s relative risk of SUDEP. Shankar et al (2013)13 have developed an evidenced based risk factor checklist to engage patients in such a discussion.
Intellectual disabilities, especially more severe intellectual disabilities, are mainly caused by brain pathology, that is maldevelopment of or damage to the brain. Usually we assume that the brain problem gives rise to both the intellectual disabilities and the epilepsy (Bowley and Kerr 2000)14:
The diagnosis of Epilepsy is clinical, and usually established by a specialist medical practitioner with training and expertise in epilepsy. Obtaining a good history of a patient with epilepsy and ID is very important and must cover information about when the epilepsy started and it’s progress over time, detailed description of the seizures (duration, frequency, daytime/nighttime, abnormal movements, abnormalities of tone, any warning signs, events and/or behaviours leading up to the seizure (preictal) and after the seizure (postictal) etc), seizure hazards (head injuries, difficulty in breathing etc.), triggers for the seizure and any family history of neurological and psychiatric disorders.
An eyewitness account is important and this can be obtained with patient’s consent where an individual has the capacity to provide this. Also collateral information from family and carers is of critical importance. It can be difficult to get enough information about the patient with Intellectual Disability reaching back into their childhood and development and this is especially so in persons with severe Intellectual Disability.
Allied professional staff in day and residential services commonly attempt to classify seizures rather than describing them. They often use the outdated terms 'grand mal' and 'petit mal'. 'Petit mal' is technically an earlier name for 'absences' and is all too often misused to cover any seizure or event that is not a typical tonic clonic seizure. Hence it is important that a description is obtained or recorded. If possible the eye witness can mime the seizure episode.
The clinical decision or diagnosis of an epileptic seizure should be based on the combination of the description of the attack and different symptoms. Diagnosis should not be based on the presence or absence of single features. If a definite diagnosis of epilepsy not possible or cannot be clearly established, further investigations and/or referral to a tertiary epilepsy specialist should be considered. Follow-up should always be arranged (NICE 2012)4.
The diagnosis of Epilepsy can be life changing, so there is a need for optimal diagnostic accuracy.
Remember - not all that shakes is epilepsy! (Rothner 1989)15.The distinction is usually made on history (Hopkins 1995)16.
The differential diagnosis can include, Syncope (vasovagal, orthostatic, cardiac arrhythmia), Psychogenic states (panic attacks, dissociative disorders), Vascular pathology (migraine, transient ischemic attacks, transient global amnesia), Sleep disorders (parasomnias, narcolepsy), Metabolic (hypoglycaemia & insulinoma, hypocalcemia) and Toxic states (drugs, alcohol).
Electroencephalography (EEG) through the use of electrodes placed on the scalp, analyses electrical changes produced by the superficial cerebral cortex. It helps in identifying the location of any epileptic focus. A normal EEG between seizures does not rule out epilepsy. Unless an actual seizure is captured on the recording, an EEG can only support a clinical diagnosis of epilepsy and should not be used in isolation. “Epileptiform” activity on an EEG does not necessarily mean that the diagnosis is epilepsy; 0.5 - 3% of the healthy population have an abnormal EEG. (Gregory et al 1993)17. Most people with intellectual disability will be able to co-operate with an EEG. Sleep deprived EEG, repeat EEG and Long-term video or ambulatory EEG increase the EEG yield. Video telemetry which combines EEG and video recording is valuable in seeing whether an identified behaviour is epileptic or not.
Neuroimaging of the brain includes Computed Tomography (CT) scanning and Magnetic Resonance Imaging (MRI). Prasher and Kerr 20081 state that CT scanning is readily available and can provide information on brain symmetry and on large potentially epileptogenic lesions like infarction or tumours. It is particularly useful where there are calcified abnormalities and skull changes. However, CT is insufficiently sensitive to use as definitive imaging in most patients with epilepsy. MRI has essentially replaced CT as the imaging of choice for epilepsy because of its sensitivity and specificity in identifying structural lesions that could be the origin of epileptic discharges. However, MRI is not always widely available, making CT sometimes still the appropriate initial investigation especially during emergencies. Functional MRI and MR spectroscopy can add additional information, sometimes identifying potentially resectable focal abnormalities in structural MRI-negative patients. With careful preparation many people with intellectual disabilities can have an MRI scan, but some will need heavy sedation or a general anaesthetic.
Electrocardiogram (ECG) is an important investigation useful in excluding possible heart conditions that could resemble epilepsy or when an individual is reported to have experienced blackouts.
NICE (2012)4 states that in the management of epilepsy patients should have access to a specialist (epilepsy) service and have a comprehensive care plan agreed. As already mentioned above epilepsy is more common in people with Intellectual Disability but can also be more difficult to treat, so the emergency treatment of epilepsy in this group is important (Pellock & Morton, 2000)18. Also in this group they can be on other medications that lower the seizure threshold increasing their risk of seizure occurrence. There are multiple outcomes that might be the focus of treatment. The principle aims of management are for the patient to be seizure free and free from any adverse effects. However this cannot be fully realized especially given the difficulties in diagnosis and higher potential of treatment resistance. In such a situation it would be good to help the patient make informed choices on what outcomes realistically he or she would look for. Where the patient is lacking the mental capacity to make or participate in making these choices a best interest meeting as per the MCA guidance with key stakeholders would provide apt guidance and goals for seizure management. The current management can comprise of pharmacological treatment in the form of antiepileptic drug (AED), Vagus nerve stimulation (VNS), and Resective surgery.
The management approach must be centred on the needs and wishes of the person with epilepsy and take into account their experiences and social context. Education about epilepsy is important for all those with epilepsy and those that support them. Video, pictures and photographs can be used to support education, which should be directed towards families and care staff as well as the person with epilepsy. Language, sequencing and memory difficulties may contribute to poor adherence to a treatment regime. However it must be kept in mind that a ‘one size fits all’ approach even using ‘easy read’ or communication via videos etc. has their limitations and possible use of communication experts such as speech and language therapists might be useful. People with intellectual disabilities and epilepsy have typically experienced very little control of their own lives. Resentment over this may also lead to difficulties.
AEDs are the mainstay treatment for epilepsy. This should be individualised starting with a single AED (monotherapy) wherever possible (NICE 2012)4. Should this be unsuccessful, another AED (monotherapy) should be used. Usually when a monotherapy is unsuccessful or patient develops adverse effects the 2nd AED is introduced and built up to a therapeutic or tolerable dose before the first AED is slowly withdrawn. Combination therapy should only be considered if monotherapy fails. Though some AEDs work best against particular seizure types, several AEDs may need to be tried (Feely 199919, Kerr et al 200110, Livanainen et al 199820).
Patients on AEDs need to be monitored for adverse effects. All anti-epileptic drugs cross the blood brain barrier. All therefore have the potential to produce adverse effects on alertness, cognition and mental state. These effects may be particularly pronounced in people with intellectual disabilities (Espie et al 1990)21. In addition, people with intellectual disabilities may be less likely to complain of side effects, or to have their complaints recognised. Details can be obtained from the British National Formulary (BNF 2014)22.
Blood monitoring does not need to be routinely done unless clinically indicated. AEDs should be introduced and withdrawn slowly with the aim of achieving the lowest effective dose. It is dangerous to stop AEDs suddenly, because this may precipitate status epilepticus. People with intellectual disabilities and their carers may not understand the importance of adhering to a treatment regime. A simple regime, the use of pictures and close liaison with the pharmacist all help. Click here to see related articles on Clinical Communication(Thacker 2002)23 or the use of pictures to communicate with people with intellectual disabilities(Hollins 2003)24. So health care professionals have a role in educating patient, carers and family in understanding epilepsy, the rationale for treatment, reducing stigma attached and developing positive relationships (NICE 2012)4.
If a patient is seizure free for a period of 2 years whilst on AED then withdrawal of AED maybe considered. This should however be discussed with patient, their carers and/or family where possible. Withdrawal of the AED should be monitored and under the guidance of a specialist (NICE)4. Withdrawal of AEDs, even when optimally undertaken, can be associated with re-emergence of seizures.
Individuals with Intellectual Disability are more likely to have status epilepticus (Pellock et al 2000)25. The mortality risk is also increased this patient group. The treatment of status epilepticus is considered a medical emergency. NICE (2012)4 states that treatment should be given if the individual has a prolonged (convulsive) seizure that lasts for 5 minutes or more or if seizure occurs 3 or more times in an hour. Treatment option available in the community include buccal midazolam (first-line treatment) and rectal diazepam (if midazolam is not available). The administration of rectal Diazepam in the community raises dignity issues. Other medications can be prescribed within the hospital setting. Depending on the individuals personalised care plan and their response to this treatment an ambulance needs to be called if seizure carries on after the administration of treatment and/or if there are concerns about their breathing, airway or other vital signs.
Carers and family need to be appropriately trained in the administration of these rescue medications. Standards of training however vary across the UK with potential consequences that could be serious for the individual patient given the risk of brain damage and mortality. An online training can be accessed by families and carers. It is principally for families and carers of patients living in Cornwall; however ‘throwaway’ account and a guest log in have been created for sampling portions of the training. Username: EpilepsyTest, Password: epilepsy Website: http://www.skillboostersonline.com/cornwall/ (Shankar 2014)26. This has been developed as a standardized test which checks on basic learned competencies as recommended by the Joint Epilepsy Council (JEC 2014)27.
Vagus nerve stimulation (VNS)
Although AEDs remain the main treatment for intractable epilepsy, a significant proportion of persons with ID will have intractable epilepsy. Espie et al (1990)21 and Singh et al (1993)28 state that AEDs remain the principal form of management for intractable epilepsy with up to 40% of individuals on polytherapy but poor seizure control is still evident, which means that alternatives need to be considered. Prasher et al (2008)29 states that Vagus nerve stimulation (VNS) therapy can be an alternative to AEDs for individuals with Intellectual Disability who suffer from intractable epilepsy. NICE (2012)4 also states that VNS is indicated for use as an adjunctive therapy in reducing the frequency of seizures in adults who are refractory to AED and are not suitable for resective surgery. VNS although relatively safe for patients with ID where there are communication and capacity issues prior a surgery is undertaken. It is important that various side effects including a rare long term side effect of VNS on the heart (Shankar et al 2013)30 be kept in mind while working with people with VNS.
Epilepsy in people with Intellectual Disability can be refractory to AEDs and so can be potentially suitable for respective surgery. The main role of epilepsy surgery is to achieve seizure freedom, or a significant reduction in seizure frequency, without producing adverse cognitive or psychological effects (Nicolson 2008)31. The risks to the patient of ongoing refractory epilepsy should be considered when contemplating the possibility of epilepsy surgery.
Cognitive activity is affected by the underlying brain pathology, by the effects of repeated interruptions in consciousness and by anti-epileptic drugs. All tend to reduce cognitive function. This may lead to sedation and poor motivation, or it may be expressed as irritability, impulsiveness and disinhibition (Espie et al 1989)32.
Repeated disruption of consciousness interrupts memory and learning. This is a particular problem in 'absence' seizures, where the seizures are brief and may be unrecognised, but are often frequent, especially in children. A person with undiagnosed partial status epilepticus may resemble someone with severe intellectual disabilities or autism. When their epilepsy is treated, their whole demeanour may change dramatically.
Children with epilepsy are often seen as very precious and vulnerable by their families. This may lead to few demands being placed on them, or infantilisation. Epilepsy can have a negative effect on self-esteem. It is a hidden disability, but one that can be internally stigmatising (Scambler 1998)33.
Some AEDs, particularly but not exclusively Vigabatrin can produce behaviour problems and even psychosis.
Psychological disturbance may occur before, during or after a seizure. Pre-ictal - People with complex partial seizures commonly experience a warning or aura which may take the form of a particular emotional state or a hallucinatory experience; Peri-ictal - Some seizures, particularly complex partial seizures affecting the temporal or frontal lobes, result in the person behaving in a bizarre and stereotyped way, though they are partly conscious; Post-ictal - After a seizure many people sleep, some have headaches and many are irritable or confused. (Fenwick 1995)34.
Watching your own child have a convulsive seizure is terrifying. People unfamiliar with epilepsy usually think the child is dying. For some parents, and some people with epilepsy, this fear persists. There are also real risks of serious injury, for example by falling under a bus, or into deep water. Services are afraid of litigation. It is not surprising that people with epilepsy and intellectual disabilities are sometimes offered more protection than they need.
People with epilepsy can usually only drive if they have been free of seizures for a year (Shorvon 1995)35 . However it is important that if this is an issue the latest advice is taken from the GP and/or the DVLA. Most people with intellectual disabilities do not drive. However, transport can still be a problem – practical issues need to be considered for example there may be problems to use public transport or taxis without an escort, and sometimes no escort is available.
Seizures further limit access to employment, leisure and sporting activities (Scambler et al 1990)36. They therefore contribute to poverty and social isolation. This in turn contributes to a sense of powerlessness and low self-esteem. In some cultures, epileptic seizures are seen as evidence of demonic possession or of infection. This can mean that people are reluctant to touch or share cutlery with anyone who has seizures.
Rescue medication, in the form of rectal diazepam can pose particular difficulties. It is useful in the prevention of status epilepticus in vulnerable individuals and can be given by specially trained, but otherwise unqualified people. It can enable people with intellectual disabilities to avoid frequent in-patient admissions. However staff may be reluctant to use it. They may fear injuring the personal that there could be accusations of sexual abuse.
An individually based assessment of the real risks of particular activities and treatments will often allow the person to lead a much fuller life. An epilepsy care plan, centred on the person with epilepsy and involving everyone with a responsibility to care for them, is helpful. Such a plan should form part of the Health Action Plan recommended by the UK White paper, Valuing People (2001)37.
This will usually involves assessing the patient’s level of risk and depends on the individual, their environment, frequency and severity of epilepsy (IASSID 2001)38. NICE (2012)4 suggests that professional be aware of the higher risk of in individuals with Intellectual Disabilities and epilepsy and that these be discussed with the individual, their families and/or carers. NICE (2012)4 also recommended that a risk assessment takes place and includes, bathing and showering, preparing food, using electrical equipment, managing prolonged or serial seizures, the impact of epilepsy in social settings, SUDEP and the suitability of independent living.
The British Epilepsy Association issue excellent leaflets on Epilepsy and Sport, Leisure, Employment and Computers for example. The emphasis should be on having strategies in place to prevent injury from occurring if the person has a seizure, rather than restricting their activities. For example, 'swim only when there is a life guard. It is safer if you also swim alongside a friend.' 'Stand well back from the platform until the train has stopped’. (Forjuoh 200139, Besag 200140).
1. Prasher, VP, Kerr MP. (2008). Epilepsy and Intellectual Disabilities. Springer
2. Fisher SF, Acevedo C, Arzimanoglou A, Bogacz A, Cross JH, Elger CE, Engel Jr J, Forsgren L, French JA, Glynn M, Hesdorffer DC, Lee BI, Mathern GW, Moshe SL, Perucca E, Scheffer IE, Tomson TC, Watanabe M, and Wiebe S. (2014). A practical clinical definition of epilepsy. Epilepsia, 55(4):475–482.
3. Commission on Classification and Terminology of the International League Against Epilepsy. (1989). Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 30: 389 – 399.
4. The National Institute for Health and Care Excellence (NICE). (2012). The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care. NICE clinical guideline 137 guidance.nice.org.uk/cg137
5. Sander JW, Shorvon SD. (1996). Epidemiology of the epilepsies. J Neurol Neurosurg Psychiatry 61: 433- 443.
6. Bell GS, Sander JW. (2001). The epidemiology of epilepsy: the size of the problem. Seizure 10(4):306-314.
7. Amiet C, Gourfinkel-An I, Bouzamondo A, Tordjman S, Baulac M, Lechat P, et al. (2008). Epilepsy in autism is associated with intellectual disability and gender: evidence from a meta-analysis. Biological Psychiatry 64:577-82.
8. Branford D, Bhaumik S, Duncan F. (1998). Epilepsy in adults with learning disabilities. Seizure7:473-77.
9. Matthews T, Weston N, Baxter H, Felce D, Kerr M. (2008). A general practice-based prevalence study of epilepsy among adults with intellectual disabilities and of its association with psychiatric disorder, behaviour disturbance and carer stress. Journal of Intellectual Disability Research 52:163-73.
10. Kerr M, Bowley C. (2001). Evidence-based prescribing in adults with learning disability and epilepsy. Epilepsia 42(Suppl. 1):44-45.
11. Kerr M, Bowley C. (2001). Multidisciplinary and multiagency contributions to care for those with learning disability who have epilepsy. Epilepsia 42(Suppl. 1):55-56.
12. Nashef L (1997) Sudden unexpected death in epilepsy: terminology and definitions. Epilepsia 38: S20–2.
13. Shankar R, Cox D, Jalihal V, Brown S, Hanna J, McLean B (2013) Sudden unexpected death in epilepsy (SUDEP): Development of a safety checklist. Seizure 22:812–817.
14. Bowley C, Kerr M. (2000). Epilepsy and intellectual disability. J Intellect Disabil Res 44(Pt 5):529-543.
15. Rothner AD. (1989). ’Not everything that shakes is epilepsy'. The differential diagnosis of paroxysmal nonepileptiform disorders. [Review]. Cleveland Clinic Journal of Medicine, 56 Suppl Pt 2:S206-S213.
16. Hopkins A, Shorvon S, Cascino G. (1995). Epilepsy. 2 ed. London: Chapman & Hall.
17. Gregory RP, Oates T, Merry RTG. (1993). EEG epileptiform abnormalities in candidates for aircrew training. Electroenceph Clin Neurophysiol 86: 75 – 77.
18. Pellock JM, Morton LD. (2000). Treatment of epilepsy in the multiply handicapped. Ment Retard Dev D R 6: 309 - 323.
19. Feely, M. (1999). Drug treatment of epilepsy. BMJ 318 (9 January):106-109.
20. Livanainen M, Alvarez N. (1998). Drug treatment of epilepsy in people with intellectual disability. JIDR 42 Suppl 1:iv.
21. Espie CA, Gillies JB, Montgomery J M. (1990). Antiepileptic polypharmacy, psychosocial behaviour and locus of control orientation among mentally handicapped adults living in the community. J Ment Defic Res. 34: 351 – 360
22. Joint Formulary Committee. (2014). British National Formulary. 67th ed. London: BMJ Group and Pharmaceutical Press
23. Thacker, A. (2002). Clinical Communication. Available: http://www.intellectualdisability.info/how-to../clinical-communication. Last accessed 20th July 2014.
24. Hollins, S. (2003). Books Beyond Words: Telling the Whole Story in Pictures. Available: http://www.intellectualdisability.info/how-to../books-beyond-words-telling-the-whole-story-in-pictures. Last accessed 20th July 2014.
25. Pellock JM, Morton LD. (2000) Treatment of epilepsy in the multiply handicapped. Ment Retard Dev D R 6: 309 - 323.
26. Rohit Shankar Testing Competency in Delivering Epilepsy Protocol Medication Advances in clinical neuroscience & rehabilitation: ACNR 06/2014; 14(2):31
27. Joint Epilepsy Committee. (2014). Buccal Midazolam Guidelines. Available: http://www.jointepilepsycouncil.org.uk/resources/buccal_midazolam.html. Last accessed 29th Jul 2014.
28. Singh BK, Towle P O. (1993) Antiepileptic drug status in adult outpatients with mental retardation. Am J Ment Retard 98: 41 – 46.
29. Prasher, VP. Furlong, E. and Weerasena, L. (2008). Vagus Nerve Stimulation Therapy: An Intellectual Disabilities Perspective. In: Prasher, VP and Kerr, MP. Epilepsy and Intellectual Disabilities. London: Springer. p109-128.
30. Shankar R, Olotu V, Cole N, Sullivan H, Jory C. (2013) Case report: Vagal nerve stimulation and late onset asystole. Seizure. 22 (4):312–314.
31. Nicolson, A. (2008). Resective Surgery for Patients with Epilepsy and Intellectual Disabilities. In: Prasher, V. and Kerr, M. Epilepsy and Intellectual Disabilities. London: Springer. p129-151.
32. Espie CA, Pashley AS, Bonham KG, Sourindhrin I, O'Donovan M. (1989). The mentally handicapped person with epilepsy: a comparative study investigating psychosocial functioning. Journal of Mental Deficiency Research 33:123-135.
33. Scambler G. (1998). Stigma and disease: changing paradigms. Lancet 352(9133):1054-1055.
34. Fenwick P. (1995). Psychiatric Disorder and Epilepsy. In: Hopkins A, Shorvon SD, Cascino G, editors. Epilepsy. London: Chapman Hall, p453-502.
35. Shorvon SD. (1995) Epilepsy and driving. BMJ 310:885-886.
36. Scambler G, Hopkins A. (1990). Generating a model of epileptic stigma: the role of qualitative analysis. Soc Sci Med 30(11):1187-1194.
37. Department of Health (2001) Valuing People: A New Strategy for Learning Disability for the 21st Century: Implementation. Department of Health, London.
38. International Association of the Scientific Study of Intellectual Disabilities (IASSID). (2001) Clinical guidelines for the management of epilepsy in adults with an intellectual disability. Seizure 10: 401 – 409.
39. Forjuoh SN, Guyer B. (2001). Injury prevention in people with disabilities. BMJ; 322:940-941.
40. Besag F. (2001). Lesson of the week: Tonic seizures are a particular risk factor for drowning in people with epilepsy. BMJ; 322:975-976.
This article was first published on the site in 2003. It was revised and updated in 2015.