Seizures
 |
The Autistic Spectrum |
Some Facts About Epilepsy Terminology To Avoid Seizures Explained I. Partial (focal, local) seizures A. Simple partial seizures (consciousness is not impaired) 1. With motor symptoms B. Complex partial seizures (with impairment of consciousness) 1. Beginning as simple partial seizures and progressing to
impairment of consciousness 2. With impairment of consciousness at the start C. Partial seizures evolving to secondarily generalized seizures 1. Simple partial seizures evolving to generalized seizures II. Generalized seizures (convulsive or non-convulsive)
A. Absence seizures 1. Absence seizures B. Myoclonic seizures III. Unclassified epileptic seizures (1.) somato = body; sensory = relating to the senses
or the power of sensation.
|
|
 
When an individual is aware of the beginning, it may be thought
of as a warning or aura. On the other hand, an individual may not be aware of the beginning and therefore have no warning.
Sometimes, the warning or aura is not followed by any other symptoms.
It may be considered a simple partial seizure by the doctor.
The middle of the seizure may take several different forms. For
people who have warnings, the aura may simply continue or it may turn into a complex partial seizure or a convulsion. For
those who do not have a warning, the seizure may continue as a complex partial seizure or it may evolve into a convulsion.
The end to a seizure represents a transition from the seizure back
to the individual’s normal state. This period is referred to as the “post-ictal period” (an ictus is a seizure)
and signifies the recovery period for the brain. It may last from seconds to minutes to hours, depending on several factors
including which part(s) of the brain were affected by the seizure and whether the individual was on anti-seizure medication.
If a person has a complex partial seizure or a convulsion, their level of awareness gradually improves during the post-ictal
period, much like a person waking up from anesthesia after an operation. There are other symptoms that occur during the post-ictal
period and are detailed below.
Please note: Below is only a partial list, some people may experience
other symptoms not listed below. These lists are meant to help patients communicate with their physicians.
Early seizure symptoms (warnings)
Seizure symptoms
After-seizure symptoms (post-ictal)
If you or someone you know has the symptoms listed above -- you are not alone. Below are personal stories by people who have either experienced or witnessed seizure symptoms. Source: http://www.epilepsy.com/101/ep101_symptom.html ********************************************* Epilepsy - A Parents' Guide Many people with epilepsy experience their first seizure before the age of 20. So, if your child has developed epilepsy, you are not alone and, these days, there's a good chance that her/his condition can be kept well under control. Childhood epilepsy varies enormously in type, degree or severity and can be linked with other problems. Most children with straightforward epilepsy have a perfectly normal, active childhood and, with a few sensible safety precautions, are able to enjoy doing all the things their friends do, like swimming, sports and games and so on. Sometimes, however, the condition is more serious, and children need long-term treatment and support. Hopefully this guide will help you, as a parent or carer, to understand your child's condition so you can encourage her/him to grow into a happy, independent individual who is confident about the future. Epilepsy can begin at any age but it often starts early in life. Although some people believe it is linked with physical disability or mental handicap, in fact most children with epilepsy have exactly the same range of intelligence and abilities as unaffected children. Some do have physical or mental problems as well as seizures, which may be linked to brain damage or disease. It's usually these underlying problems which have caused epilepsy, however, rather than the other way round. Is it my fault? Like many parents you may wonder whether something you did or failed to do sparked off your child's epilepsy, and searching for a cause is part of your attempt to come to terms with your child's condition. However, it's highly unlikely that anything you did is responsible for your child's seizures and, in many cases, the cause of epilepsy is a mystery. Spotting epilepsy in childhood It can be very frightening to see your child having what appears to be a seizure. However, it's important to keep calm so you can describe exactly what happened to the doctor. Epilepsy is often difficult to diagnose, and it is not always clear whether a child has had a seizure. If your child collapses for any reason at all contact your doctor. Children, like adults, can have either generalized or partial seizures. Other conditions can sometimes be mistaken for epilepsy and it's important for the doctor to exclude these. They include febrile convulsions and breath-holding attacks. Febrile convulsions These convulsive seizures are caused by a rapid rise in temperature and linked to childhood illnesses such as tonsillitis and teething. Fortunately, most children grow out of them by the time they start school. Also see Febrile Seizures down below. Breath-holding attacks These are an extreme reaction to shock or frustration. Instead of screaming with fear, pain or anger, the child screams once, draws a huge breath as if to carry on and then holds it for so long she/he passes out. This causes the child to stop holding her/his breath. Although alarming to witness, your child can't do himself lasting physical harm during such an attack. Difficult to control epilepsy (epilepsy 'plus') Although the outlook is good for most children with epilepsy, some children have severe forms of the condition which are difficult to control with drugs and continue having seizures. They can include various 'syndromes'. A syndrome is a group of symptoms. The medical specialist can identify an epilepsy syndrome by the type of seizures your child has, when she/he develops them and other identifying signs and symptoms. Children with difficult to control epilepsy may have other problems, such as delayed development and learning difficulties and for this reason doctors often use the term 'epilepsy plus'. It's always a blow to learn that your child has a condition that may not go away and it's common to go through a period of grieving as you get used to the idea. Diagnosis Your observations and knowledge of your child are vital in helping the doctor reach a diagnosis. As well as the usual diagnostic tests, such as blood tests, EEG and brain scans, your child may also be referred for development and behavioral checks to assess her/his overall progress. Talking it over You will need plenty of time to ask questions and voice any worries you may have about your child's diagnosis. Your doctor can give you information, advice and reassurance, but in a busy surgery there is not always time for long discussion. Ask whether you can arrange a special appointment or, alternatively, there may be a counselor at the surgery or a special epilepsy liaison nurse at the hospital clinic. You may be shocked to discover your child has epilepsy, but remember - eight out of ten children who have the condition lead trouble-free, enjoyable lives. Treatment and management ~ Medical treatment The aim of medical treatment is to control your child's tendency to have seizures, so she/he can get on with life with as little disruption from epilepsy as possible. Avoiding the things which may trigger seizures and taking anti-epileptic drugs are the main ways to achieve this. Your child will usually need to stay on anti-epileptic drugs until she/he has been free from seizures for at least two years, and in certain cases she/he may need to continue taking anti-epileptic drugs indefinitely. Usually your child will move from the pediatrician (children's specialist) to adult care at around 16 years of age, but this may vary. Surgery Surgery is another option which is becoming more widely available for a few children with certain types of epilepsy. Also see Surgery down below. Diet Some children with certain difficult to treat forms of epilepsy may be helped by going on a high-fat diet called a ketogenic diet. Unfortunately it's often difficult to follow and can make your child feel unwell, but it can be worth trying if your doctor recommends it. Always check with your doctor before placing your child on a special diet. See Ketogenic Diet below. When you first learn that your child has epilepsy you may be frightened and panicky. You may worry about how her/his epilepsy will effect her/his childhood and be concerned that the anti-epileptic drugs may have side effects, all of which is perfectly understandable. The problems you encounter are unique to your family, and realistically you may have to be prepared for some difficult times. However, most families cope well once they understand what epilepsy involves and learn how to manage it. Staying positive Your own common sense, experience and intuition will guide you as to how best to care for your child. Finding out as much as you can about the condition will help you build up confidence in yourself and your ability to respond to her/his needs. Try not to be overprotective or concentrate all your attention on the child with epilepsy. Other people You may fear that friends, neighbors and relatives will react badly to the news that your child has epilepsy. Negative reactions are most likely when people are afraid or don't know what epilepsy involves. Openness and honesty are the best ways to combat any stigma surrounding epilepsy and you will probably find that most people are sympathetic and supportive if they know how they can help. Epilepsy & behavior Few families - whether they have a child with epilepsy or not - escape behavioral problems at some stage. It's rare for these to be a direct result of epilepsy and it's a myth that there is an 'epileptic personality'. Some children's seizures are made worse by stress, emotional upset or boredom, and in some cases difficult behavior can sometimes be caused by certain anti-epileptic drugs. Sometime, simply missing out on information during an absence seizure or having to miss an outing because of an attack can leave the child feeling frustrated or confused, leading to behavior problems. If your child does develop a problem, try to find out what is causing it if you can. The professionals who are involved with your child can help too so don't be afraid to talk to them and ask for help. Some children with epilepsy are picked on at school. This may be because they lack confidence and don't feel able to assert themselves. Signs can include temper tantrums, violence, or sudden misbehavior like playing truant, or nervousness. Talk to your child's teacher if you are worried and make sure your child knows she/he has your support and encouragement to stand up for her/himself. Helping your child live with epilepsy Accurate information combined with a positive outlook will help you and your child to enjoy her/his childhood. Tell her/him as much as you think she/he can understand about epilepsy and start showing her/him simple ways to manage the condition. As she/he gets older you can encourage her/him to take increasing responsibility for her/him self. The following guidelines may be useful: DO -
DON'T -
Managing a young child Young children learn by doing so it's up to you to encourage her/his natural urge to explore. Your child will benefit from going to mother and toddler group and, later, playgroup or nursery, but make sure the staff and any volunteer helpers know she she/he has epilepsy and what to do if she/he has a seizure. See Teacher's Guide and more down below. Most children and young people with epilepsy attend ordinary schools, colleges and universities. School is a central part of your child's life and fortunately she/he should be able to take part in most activities just like any other child. You will probably find that most teachers and helpers are accepting and helpful once they know what is involved in your child's condition. For example they need to know that she/he doesn't have to be sent home every time she/he has a seizure, but can return to class after a suitable rest period. Some schools have a written policy on epilepsy - the school nurse will be able to help you. Epilepsy & learning Most children with epilepsy are just as capable of learning as other children, and many do very well indeed. However, it's a sad fact that some don't achieve as much as they could at school. Your child's lack of attainment may not be directly linked to epilepsy at all, so if you suspect that she/he is not progressing as well as she/he could, have a word with the teacher and the doctor to try and pinpoint the problems. Learning difficulty Some children with epilepsy do have learning difficulty (the term used to describe a child who finds it harder to learn than most children of the same age, or who has a disability which makes it difficult to make use of the school's facilities). In this case your child will need special help to reach her/his full potential. Fortunately, most learning difficulties are mild and overcome quite quickly, but sometimes they last longer and are more serious. Your child is most likely to experience serious learning difficulty if she/he has severe, uncontrolled seizures and/or physical and mental problems as well as epilepsy, in other words 'epilepsy plus'. Special educational needs If your child is falling seriously behind other children of the same age, or if you think she/he isn't getting all the help she/he needs at school she/he may have special educational needs. This involves collecting information about your child's progress from you, your child's teacher, an educational psychologist and anyone else who can help give a picture of your child's needs. Should my child go to a special school? Most children with special educational needs can be educated in an ordinary school, perhaps with the help of outside specialists, but sometimes a child with severe learning difficulties may do better at a special school, where her/his needs can be met more easily. All adolescents need help in learning to accept and like themselves as they are. It's very common for teenagers with epilepsy to use their condition as a peg on which to hang their anxieties and discontents, for example by rebelling over taking their tablets. Worrying though this is, try not to make it into a big issue. The more your teenager understands about her/his medication the better able she/he will be to make responsible decisions. With your love and support your teenager can learn that epilepsy doesn't have to rule her/his life. Provided they are sensible there's no reason why young people with epilepsy shouldn't take part in sports, traveling, going to discos and having boyfriends or girlfriends. As a parent it can be hard to acknowledge that your children have adult desires. However, at some stage you will need to discuss sex and relationships. Boys and girls need to know that epilepsy won't stop them enjoying sex. Girls should be aware that medication can affect absorption of the contraceptive Pill and may need to talk this over with the doctor. And both sexes need to know that there's absolutely no reason why they can't have a partner or children. Above all your teenager needs your understanding. The strong need to belong, which she/he shares with all teenagers, may make it especially hard when she/he can't be like her/his friends because of problems linked to epilepsy. For instance, she/he will only be able to learn to drive if she/he has been seizure-free for a year - this can be very isolating when all your friends are learning to drive. Learning to deal with such issues - with your support - is all part of learning to be independent and manager her/his own epilepsy and to recognize that epilepsy doesn't have to rule her/his life. Preparing for adulthood Use the following checklist to make sure your teenager has all the information she/he needs:
See contraception, pregnancy and self management down below. Later on your child will need to decide whether to go on to further or higher education. It's a good idea to encourage her/him to aim as high as possible in order to compete in the job market when the time comes - an important factor for people with epilepsy. Many further and higher education institutions today make a real effort to cater for their students with special needs of any kind, giving them priority for a place in a hall of residence, for example. There's no reason why your child shouldn't enjoy every aspect of student life. She/he will need to decide who to tell about her/his epilepsy and what to tell them. Epilepsy Action believes that honesty is the best policy. Being open avoids embarrassment and enables her/him to get any help she/he needs if the occasion arises; it can also help quash some of the unhelpful myths about epilepsy. Like all students, your child will need to decide for her/himself where she/he stands on matters such as alcohol, street drugs and how she/he conducts her/his social life. In making such choices, she/he will, of course, need to take into account how these are likely to affect her/his epilepsy. If she/he encounters particular problems linked to epilepsy, she/he can discuss them with a personal tutor or student counselor. And, of course, Epilepsy Action is always on hand to provide information on all aspects of epilepsy. Febrile Seizures Febrile seizures, also known as febrile convulsions, are the immature brains response to a rapid rise in body temperature. In medical circles, the term febrile is used to define a body temperature of 38 degrees C or above. Seizures triggered by febrile illnesses are common in children between the ages of 6 months and five years. For many children the fever will be caused by a minor infection such as a sore throat or ear infection, but sometimes more serious conditions such as meningitis or encephalitis can also cause a rapid rise in temperature and trigger a febrile seizure. Generally, children under the age of 5 years. It is estimated that between 2-4 per cent of all children under the age of 5 will experience at least one febrile seizure. Children of parents with a history of febrile seizure are four times more likely than children in general to have febrile seizures themselves. Brothers and sisters of children with febrile convulsions have an 8 per cent risk of seizures when experiencing a febrile illness. While febrile convulsions are not considered to be epilepsy, children of parents with epilepsy have a 5 per cent chance of developing febrile seizures. Boys appear more vulnerable than girls. Over 75 per cent of febrile seizures are said to be simple, that is, lasting less than 15 minutes and generalized which means that a large part, or even the whole of the brain, is involved. The remaining 25 per cent are termed complex. This means they involve only a small part of the brain or they are repeated in the same period of acute illness, or prolonged, (lasting more than about 15 or 20 minutes). This type may occasionally cause some temporary paralysis, known as Todds Paresis, afterwards. How are febrile seizures managed? Witnessing any convulsion can be a frightening event. They usually happen very suddenly, often when a child has seemed only slightly under the weather. As most people do not know how to cope with the initial seizure it is not uncommon for medical advice to be sought. For the first seizure this is often from paramedics, who generally take the child to hospital for assessment. Tests will be carried out to determine the cause of the rise in temperature and treatment, if any is needed, will be started. Once serious illness has been ruled out the child may be discharged and the parents given advice on temperature reducing strategies for future illnesses. This information may also be given by the family GP or Health Visitor. As febrile convulsions are not usually considered to be epilepsy, the use of long-term anti-epileptic medication is not seen to be beneficial. However, for children who have prolonged febrile convulsions, rectal diazepam may be given. This drug is designed to terminate prolonged seizures and may be administered by parents and other care-givers. If this is the case, it is important that the prescribing doctor issues clear guidelines about how and when it should be used. General information about the administration of rectal diazepam is also available from Epilepsy Action. Do febrile convulsions cause epilepsy? While febrile convulsions are not considered to be epilepsy, they are associated with a 2-5 per cent chance of developing epilepsy at a later date. For complex febrile convulsions that figure rises to around 10 per cent . It must also be considered that some young children who already have a predisposition to epileptic seizures will have seizures when ill, even with minor colds and infections. These seizures need to be differentiated from the seizures purely triggered by a high temperature. For this reason, a careful assessment is needed, as children with epilepsy are more likely to be given anti-epileptic medication than children with febrile seizures only. Will a febrile seizure affect a childs development? The development after a febrile seizure will closely reflect what it was before the attack. This means that a child who was not developmentally delayed before a simple febrile convulsion is unlikely to develop problems after the seizure. Occasionally, a febrile seizure is the first sign of some other illness or condition. For these children the outlook will obviously depend on the nature of that illness or condition. Epilepsy Surgery Surgery for epilepsy is advancing all the time, with new techniques, new equipment and an increasing number of surgeons interested in this area of epilepsy treatment. The result has been a steadily growing number of people undergoing this surgery and many of those people going on to enjoy a much better quality of life. The success of modern surgery for epilepsy has caused a widespread interest in this type of treatment, with people seeing an operation as preferable to a lifetime on medication. However, only a small number of people with epilepsy are suitable for surgery and, even for those that are, there are no guarantees of success. This page looks briefly at some aspects of surgery as a possible treatment for epilepsy. The first thing a doctor has to establish when considering surgery as an option is to establish the patients suitability. Will surgery be possible and, if so, will it be beneficial? There are a number of different types of surgery for epilepsy but the most common is the removal of a small part of the brain which is the underlying cause of the epilepsy; the focus. During this type of surgery, the more tissue that is removed the higher the risk to the patient. Therefore, only those patients whose seizures consistently begin in one small area of the brain are suitable for surgery. Sadly, this means that for the many people with epilepsy whose condition cannot be traced to a specific area of damaged tissue, surgery is not currently an option. Another consideration is the nature of the persons epilepsy. Surgery is always a risk so the benefits have to be significant. For this reason, doctors tend to only recommend those patients whose epilepsy has a very negative impact on their lives. These tend to be people who still have regular seizures despite trying a variety of medication. The doctor will want to know that surgery will greatly improve seizure control. It is the quality of a persons life that will be a main factor in the decision. In some people, a relatively small number of seizures can have a dramatic impact on their lives while others can tolerate a much higher number of seizures without it significantly affecting their well being. This decision is only the first step in what can be a long and frustrating journey. Because the surgeon will be removing a part of the brain, it is vital that as much as possible is known about the patients brain and their epilepsy before surgery takes place. After many tests the patient needs to be aware that they could then be told that surgery is not possible - not an easy thing to accept after hoping for change. While most people with epilepsy will have had a standard EEG test, they will be asked to go into hospital for a much more detailed version. The aim is to study the person having several seizures while the EEG is connected. This usually involves coming off medication and having the EEG continually recorded, sometimes for several days. In some instances, the surgeon may have to insert special electrodes onto the surface of the brain itself, although this is only done in a small number of cases. This involves using natural holes in the skull or having to create them. Throughout this type of test the patient receives a great deal of support and help from the hospital staff. The surgeon will also want to have an up-to-date image of the patients brain and this means having an MRI scan (magnetic resonance imaging -- see below). This machine creates a picture of the brain which put together with the results from the EEG often enables the surgeon to pinpoint the exact part of the brain which is causing the epilepsy. These tests will need to show that a single area of only one side of the brain is causing seizures. Some functions of the brain are shared by both sides of the brain, so removing one part on one side does not usually lead to a loss of that function. However, other functions are controlled only by one side of the brain, and the surgeon will need to be confident that these areas are not going to be damaged during any operation. A new test, recently developed is DTI (diffusion tensor imaging - see below). This measures the actual movement of water in the brain, detecting areas where the flow of water is disrupted. DTI is in very early stages of development but offers an alternative investigatory method in cases where an MRI scan does not detect any abnormalities. Other tests include PET (positron emission tomography) and SPET (single positron emission tomography), which involve injecting tiny traces of radio active substances into the body and watching which part of the brain they reach. Other tests are undertaken, for example functions like memory are tested. This can involve the Wada Test or the Carotid Amytal Test and involves anaesthetizing half of the brain and can be quite an ordeal for the patient. All of these tests can be worrying or distressing for the patient, but the medical teams offer a great deal of help and support throughout. After the tests the doctors will know whether an operation is the right way forward, offering the patient the best option for the future. The assessment of any risks will be undertaken extremely carefully and will be discussed with the patient. The type of surgery that a patient undergoes will depend greatly on what the surgeon hopes to achieve. The following is a list of some operations:
Despite the lengthy and very difficult nature of brain surgery, most patients make a rapid recovery and are usually up and about within a couple of days. Between eight and fifteen weeks later, most people are able to return to work. Some aspects, like waiting for the nerves that supply sensation to the skull, may take some time to recover. Some people may experience seizures just after the operation due to temporary swelling. This does not mean that the operation has failed. Depending on the persons own doctor, it may be some time before the patient can start reducing their medication. However, many patients notice a dramatic reduction in the number of seizures, many finding that their seizures appear to have stopped. They can then look at reducing or stopping their medication in consultation with their doctor. One consequence of successful surgery that may surprise some people is the difficulty in coming to terms with life without seizures. Emotional reactions to this life change are common and can include quite severe temporary depression. Friends and family can also find it difficult to adjust to the persons new found independence. This type of reaction will depend on how long the person has had epilepsy prior to having surgery. As with most surgical techniques, there are no guarantees. Epilepsy surgery is no exception and a small number of people will find that surgery has not helped. Magnetic Resonance Imaging (MRI) Magnetic Resonance Imaging is a test which can be used to establish whether there is an underlying cause for a persons epilepsy. Explained briefly, the test involves the person lying within a large powerful circular magnet. Images are produced by changes in the magnetic field, which are then analyzed by computer. These very high quality computer pictures may highlight any lesions, scars, tumors or malformations which may be the underlying cause (focus) of the epilepsy. The first MRI scanner became available in the UK in the early 1980s. The machines are costly and therefore tend to be located in the larger hospitals. Some of the scanners are much more powerful than others - the more powerful the machine, the better the quality of the image. Not everyone has an underlying cause for their epilepsy, so carrying out an MRI scan may be irrelevant in many people with the condition and of little benefit to their ongoing treatment. Should anyone with epilepsy be concerned that there may be an underlying cause for their epilepsy and wish to have an MRI scan, they should discuss it initially with their GP. If necessary, the GP can arrange for a referral to a specialist in epilepsy for an assessment. MRI's are used to investigate many medical conditions other than epilepsy and the waiting lists can be very long. Specialists are only likely to refer those who, in their medical opinion, would benefit from an MRI scan. Further research on the causes of epilepsy is vital in order to improve the treatment and quality of life for people with epilepsy. The MRI scanner is one of the tools in research development and Epilepsy Action supports the promotion of investigatory methods for epilepsy. We continue to lobby the Department of Health to improve the medical services for people with epilepsy including increased funding of research and resources. EEG (Electroencephalogram) EEG is short for electroencephalogram, and is the name of an important investigation carried out on most patients suspected of having epilepsy. It tells us about the activity of the brain at any given time. It may show abnormal activity of the sort most commonly found in epilepsy and may show that part of the brain is working abnormally. The EEG records the ever changing but tiny electrical signals coming from the brain which are picked up by electrodes placed on the scalp. These electrodes are either small silver discs or padded silver rods, attached to the scalp using a harmless glue, sticky tape, or held in place by a rubber cap. Some people confuse ECT with EEG. ECT is a form of treatment in which an electric current is applied to the head, but in an EEG there is no current passing into the head, merely tiny electrical signals coming out of the head. ECT is a form of treatment used by psychiatrists. An EEG is a harmless investigation. How it works About 20 electrodes are placed over the scalp and connected by wires to the EEG machine. The original signals from the brain are very small (measured in millionths of a volt), and the EEG machine increases the size of these electrical signals so that they can be recorded on paper or computer, and this produces a permanent record which can be interpreted by the EEG Consultant. During the EEG recording the patient sits or lies down on a couch, and is asked to relax and keep still because movements of the muscles or eyes can cause large signals which may obscure the signals coming from the brain. During the test, which usually lasts less than an hour from start to finish, the patient will be asked to open or close their eyes and, at one point, to breathe deeply for some minutes, because this may increase or reveal abnormalities. They will also be asked to look at a flashing light, because some people's brains are sensitive to flickering light and this may be a reason for their having had a seizure (photosensitive epilepsy ). In most people it is usual for the flashing light to produce activity at the back of the brain at the same rate as the flash. If the flashing light produces an abnormal discharge in the EEG, the light is immediately switched off, so there is no risk of a seizure occurring. Some patients, especially those whose seizures have occurred during sleep or just after waking, may have a longer recording during natural sleep or during sleep induced by a sleeping tablet. The diagnosis of epilepsy is made from an account of the seizures given to the doctor by the patient and by someone who has actually seen a seizure. Sometimes there is doubt about the nature of the seizure, in which case it is possible to record the EEG over a period of one or more days, using a small portable EEG recorder which the patient wears on a waistbelt. Recording can thereby be made while the patient carries on normal daytime activities, and during sleep. When an attack occurs the EEG tape recording of the event can be viewed later on a special machine in the EEG laboratory. The patient keeps an account of daily activities, so that it is possible to time all events accurately and relate them to the EEG recording made at the time. This special investigation is called ambulatory EEG monitoring, and is useful in diagnosis, in relating EEG abnormality to the patient's daily activities and also in monitoring the effect of drugs, as well as providing a complete recording of EEG activity during sleep. Other special EEG techniques may be used in investigating patients referred for possible brain surgery in specialized units. Interpretation of the EEG The diagnosis of epilepsy is made from the history and not from the EEG. Further tests may help in confirming a diagnosis, may be a guide to treatment, and have sometimes provided information as to the possible cause of the epilepsy. The EEG gives information about the working of the brain, but not its structure. The CT and MRI scans give information about structure. A normal EEG does not exclude epilepsy, and an abnormal EEG does not necessarily indicate epilepsy. Certain patterns are commonly associated with epilepsy, especially spike and wave, but since this EEG pattern is inherited it may be found in people who do not themselves have epilepsy, if they have a near relative with epilepsy. A single EEG records brain activity for only a short period of time, and during this time there may be no abnormality. Thus, several EEGs may be needed and it may be necessary to record the EEG at times (such as before a period) when the patient is known to be liable to have seizures. Repeated EEGs may also be made to check progress in response to treatment. In patients with generalized seizures (absences, primary tonic-clonic seizures, myoclonic jerks) EEG abnormality is usually seen on both sides of the brain. In partial (focal) epilepsy, abnormality may be seen in a local area and there may also be some abnormality of the background rhythms. Interpretation of children's EEG records is more difficult than adults, because the EEG alters with age, an adult pattern being usually found by the age of 15 years. There is no need to stop medication before having an EEG, but one group of drugs, the benzodiazepines (Valium, Mogadon etc) affect the EEG and may prevent the appearance of bilateral abnormalities (they do not affect focal abnormalities). This group of drugs should therefore not be taken for two weeks before an EEG, but the decision about stopping drugs must only be made by a doctor. The Ketogenic Diet The ketogenic diet is a high fat, adequate protein, low carbohydrate diet designed to mimic many of the biochemical changes associated with prolonged starvation. First developed in the early 1900s, and successfully used for the treatment of seizures in children during the 20s and 30s, the ketogenic diet was then gradually forgotten as new anticonvulsant medications were developed. The ketogenic diet has recently been rediscovered and is achieving increasingly widespread use. Its modern day role as alternative management for children with difficult-to-control epilepsy is currently being re-defined. The ketogenic diet is not a fad or a quack diet, but rather is an alternative medical treatment for children with difficult-to-control epilepsy. The ketogenic diet should only be used under the supervision of a physician and a dietician. Fasting to achieve control of seizures was described in both the Bible and during the Middle Ages, but it was only during the early 1920s that scientific papers first appeared describing the beneficial effects of prolonged fasting for children whose epilepsy could not be controlled by the few medications then available. These papers claimed that starvation, drinking only water for 10 to 20 or more days, could result in control of seizures for prolonged periods of time. During this era, when the metabolic effects of diabetes were also being studied, it was noted that the biochemical effects of fasting could be mimicked by eating a diet high in fat, but with insufficient carbohydrate to completely burn the fats. The resulting ash from the incompletely burned fat consisted of ketones in the blood. Multiple clinical papers during the 1920s and 30s reported that approximately a third of children taking this ketogenic diet had their seizures largely controlled, a third had a substantial improvement in seizure control and a third received no substantial benefit. The mechanism(s) by which these ketone bodies, principally beta hydroxybutyric acid, decrease, or even, completely control, seizures in children remain(s) unknown even today. After the discovery of phenytoin in 1938, attention turned from the ketogenic diet to the development of new anticonvulsant drugs. As new drugs were developed, the ketogenic diet was used less frequently, and since fewer dieticians were trained in the subtleties of the diet, it was used less frequently and often less successfully. In 1994, the successful treatment of a child with difficult-to-control seizures led to widespread media attention and a re-awakening of interest in the diet in the United States. The ketogenic diet is a high fat, adequate protein, very low carbohydrate diet which is carefully and individually calculated for each child. Calories are restricted and depend on the age and activity of the child. If properly calculated, the child should neither gain nor lose significant weight, but should grow normally for his/her stature and the weight should remain close to the ideal weight for height. If the child is overweight, calories are limited until the ideal body weight is approached. Fluids are also restricted, although for reasons which are less clear. The diet provides approximately 90 per cent of the childs caloric requirement as fat (cream, butter, mayonnaise), one gram per kilogram of body weight as protein, and minimal carbohydrate intake. The diet must be supplemented with vitamins and calcium. The diet was designed to simulate many of the metabolic effects of starvation. During starvation, the body first uses its store of glucose and glycogen, then begins to burn the stored body fat. When there is not sufficient glucose available, the fats cannot be completely burned and ketone bodies (acetoacetate and beta hydroxy butyrate) are left as the residue of incompletely burned fat. The ketogenic diet provides exogenous fats (fat from outside the body) for the body to burn, but limits the available carbohydrate so that ketone bodies build up. It is the high level of these ketones which appear to suppress seizures. So what do these children eat? The children are only permitted to eat the prescribed, carefully calculated meals. While the portions are small, the ketosis suppresses appetite and thirst and after a short period of adjustment children are rarely hungry. While a common reaction to the concept of such a high fat diet both from physicians and others is "Yuck", well prepared ketogenic meals can be both tasty and appealing. A typical breakfast might include a mushroom omelet with several slices of bacon and hot chocolate made with 36 per cent cream. Lunch might include celery stalks filled with peanut butter or cream cheese, lettuce with mayonnaise and a slice of tomato, and a caffeine-free diet soda. Dinner might include a weighed portion of hot dog with ketchup or mustard, lettuce and mayonnaise, a whipped cream sundae with a strawberry and a diet soda. While the effectives of the diet has been documented in many older studies, it remains equally effective today in children with difficult-to-control seizures, despite the introduction of many new anticonvulsants. A current study from Johns Hopkins (published in Pediatrics, December 1998) evaluated the effectiveness and tolerability of the diet in 150 consecutive children. These children averaged more than 400 seizures per month before the diet and had been tried on an average of more than six different anticonvulsants. The outcomes are shown below:
It should be noted that 71 per cent of those starting the diet remained on it for more than six months and more than half remained on the diet for one year. If the diet was effective in decreasing the seizures it was, in general, well tolerated, and the most frequent reason for discontinuing the diet was that it was insufficiently effective to warrant the dietary restrictions. The diet was equally effective at different ages and in children with varying seizure types. Frequently asked questions about the diet Who should try the diet? The ketogenic diet is an alternative therapy for children who have difficult-to-control epilepsy. We have defined difficult-to-control epilepsy as having more than two seizures per week despite the appropriate use of more than two anticonvulsant medications. The diet has not been adequately studied in adults or in children under one year of age. Parents who think that the diet may be appropriate for their child should consult with their physician. The diet should never be attempted without medical supervision. Will my child be able to stop taking anticonvulsant medications? Our goal is to make all children on the diet both seizure-free and medication-free. Unfortunately this is often not possible. While some patients are able to gradually discontinue medications while on the diet, many do not become seizure-free, and many require some continued medication. Can my child have any other medications while on the diet? What about antibiotics? Many childrens medications are compounded in sugary syrups. We teach parents to be vigilant in reading labels of all medications, and to avoid all preparations which contain carbohydrates. Carbohydrates include all substances which end in -ol or -ose. The diet is often very sensitive to even small amounts of these carbohydrates. For example, we have found that suntan lotion, which contains sorbitol as its base (note the ...ol) can be absorbed through the skin and lower the ketone level resulting in seizures. What does the child do on birthdays? On holidays? For snacks at school? Parents become quite creative. Birthday cakes can be cheese cake. At Halloween one family allowed the child to trick-or-treat and then purchased the candy from the child who used the money to buy a toy. This can also work well for parties and for school. Children as young as four have been taught to say, "No thank you, Im on a magic diet". Does this high fat diet cause arteriosclerosis? (Hardening of the arteries) Studies in progress suggest that only a small percentage of children on the diet have a substantial increase in their cholesterol and triglycerides. The long term effects of the diet on heart disease and stroke are unknown, but few children remain on the diet long enough for this to become a problem. Dont children gain weight on the diet? No, they should not gain significant weight. The number of calories is carefully tailored to the needs of the child. If the child is gaining too much weight, then we decrease calories. Children appear to grow normally and should only gain weight in proportion to the increase in height. How long must children remain on the diet? Children whose seizures are completely controlled on this diet often discontinue it after being seizure-free for two years. Others continue the diet as long as they find it useful. If the diet is stopped, or the ratio decreased, and the seizures return, then the diet can either be re-instituted or the person can re-start medications. How does the diet work? It appears that the high fat intake combined with carbohydrate and caloric restriction result in ketosis. The current standard of care requires that the urine remains 4+ (160-180mml) for ketones. Recent evidence suggests that the serum ketone levels may be far more critical than those in the urine. While 4+ urine may be necessary for seizure control it may be insufficient for optimum control and calories may need to be further restricted or the ratio of fat to protein and carbohydrate may need to be increased. Studies of serum levels of ketones and their correlation with seizure control are in progress. How the ketone bodies suppress seizures is unknown, but currently an area of investigations. However, suppression of ketosis by the administration of carbohydrates may quickly result in a recurrence of seizures. The success of the diet in decreasing, and sometimes controlling, difficult-to-control seizures has re-awakened interest in how the diet works, and has started researchers looking at animal models by which it can be studied. With animal models it will be possible to study how the ketone bodies modify seizure thresholds, and the mechanisms by which the diet controls seizures. Perhaps eventually, when we understand the mechanisms, we can develop a medication which will simulate the effects of the diet. Clinical research may also alter how the diet is administered. When we are able to monitor blood levels of the ketones rather than just the urine, we may be able to better adjust the diet to achieve maximal ketosis. We may understand that higher levels of ketosis give better seizure control. We may learn how to modify the diet so that we decrease the incidence of kidney stones. We may also learn more about the effects of the diet on serum lipids, and about the long term effects of the diet. Hopefully all of these efforts over the coming years will result in better seizure control for those children with difficult-to-control epilepsy. The full results of the Johns Hopkins study can be found in the December 1998 issue of Pediatrics. No attempt should be made to change a childs diet without medical supervision.
|