There are special difficulties in diagnosing the child with epilepsy. Children, and especially adolescents, do behave strangely at times. At school, children with absence seizures may be accused of day-dreaming or lack of concentration, considered disobedient or inattentive. In adolescents especially, the irrational and sometimes truculent behaviour associated with partial complex seizures is often mistaken for a disorder of behaviour.But equally, there are serious consequences for the child if he or she is mistakenly diagnosed as having epilepsy when what they are actually suffering from is some other episode of disturbed behaviour. Breath-holding attacks and night terrors in young children, temper tantrums, fainting in school assembly and migraine are all sometimes confused with epilepsy.One of the most difficult things about epilepsy is its unpredictability and uncertainty. Even when your child has been diagnosed as having epilepsy, it may take some weeks before the pattern of their fits has been worked out, and the best medication for them has been found. You will want to know what the long-term prospects are for your child, and whether he or she will outgrow their epilepsy, and these are predictions that your doctor may be reluctant to make straight away. If there is a strong family history of epilepsy, the chances are good that your child will improve after adolescence or even that they will outgrow their epilepsy by the time they are 16.*66\193\2*
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DIAGNOSING CHILDREN WITH EPILEPSY
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Marion’s first seizure occurred when she was 14. She was at school, and had just been enjoying a quiet smoke with a few friends in a secluded corner of the playground, which was unfortunately not quite secluded enough. A sharp-eyed maths mistress with a keen sense of smell spotted a curl of smoke. As she was marching them off to see the Headmaster, Marion saved the day (or so her friends described it later) by having a seizure right there in the middle of the playground.
Marion never smoked again, because she always had a feeling that the cigarette must have somehow triggered her seizure. But she did continue to have seizures, and unfortunately they proved difficult to control. Eventually, some years later, she was referred to me. I questioned her closely about what happened when she had a seizure. When Marion thought about this she discovered that there was a pattern, though she had never realized it. She had had a seizure that morning, just after her husband had drawn her attention to the fact that he had no clean shirts. She had had a seizure a few days ago at work, soon after she had mislaid an important document. She remembered a seizure she’d had some weeks back, when she had just bought a dress which cost approximately twice what she had intended to spend. And it was then that she remembered her first seizure of all. That fitted the pattern too; it wasn’t the cigarette that had triggered the seizure, it was simply a strong feeling of guilt.
‘So now what you have to do,’ I said to her, ‘is to find some way to stop feeling guilty. Whenever you feel the guilt creeping on, why not try asking yourself “How much is this going to matter in 20 years’ time?” And if the answer’s, “Not at all,” then why feel guilty about it?’
When Marion tried this technique she found that she did indeed have fewer seizures. In fact, she described her new guilt-free attitude to life as the best anticonvulsant she had ever been prescribed!
Treatment with drugs is the best way to control seizures for nearly everyone. But it is not the only way. A new and less conventional approach to seizure control is called behavioural treatment, and it is based on the observation that by altering your behaviour you can often alter the pattern of your seizures.
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Sometimes it is important to know exactly which part of the brain is giving rise to seizures, and what type of electrical activity accompanies them. And sometimes, too, it is useful to be able to correlate what is going on in the brain with actual behaviour during a seizure. This can be helpful if it is thought that seizures may have an emotional cause and are not due to epilepsy. This kind of information can only be obtained by watching the changes in behaviour that occur during the seizure as it happens and at the same time recording the electrical activity going on in the brain.
Unfortunately, seizures cannot be created to order. It is only by doing a continuous EEG recording over a long period and videoing the person the whole time that there is a good chance of capturing one or two seizures. This process of continuous seizure monitoring is called telemetry, and is carried out in a special telemetry unit. The telemetry unit is just like an ordinary EEG department but is sited in a hospital ward.
Most units now use cable telemetry, which is felt to be more reliable than radiotelemetry. In cable telemetry the EEG electrodes are fixed to your head just as they are for an ordinary routine EEG recording. The wires from the electrodes are gathered together and lead to a little amplifier which is usually strapped to your chest. From this amplifier a cable leads to a plug in the wall and from here the signals are taken to an EEG machine and tape recorder. The lead is long enough for you to be able to get out of bed and wander around, but you are not encouraged to do too much wandering, as you always have to stay within the field of view of the video camera and it is best if you sit still in a chair as the quality of the recordings is diminished by movement.
Most units will let you unplug the cable from the wall and replug it in the ward day-room so that you can at least have a change of scenery and sit and talk to other patients, though you will still be within range of a video camera. There are also video cameras monitoring the dining area. However, you are able to unplug yourself and have a few unmonitored moments of privacy if you want to have a bath or go to the lavatory. You will usually stay in the telemetry unit for one or two weeks, being recorded 24 hours a day. Obviously, this is a very expensive procedure and so it is not carried out unless there is a very good reason for it.
Another form of telemetry, less popular but still sometimes used, is 24 hour cassette tape monitoring. Electrodes are placed on the head in exactly the same way as in cable telemetry, but the wires lead to a portable tape recorder strapped round your waist, which records your brain activity throughout the 24 hours. You can wear this anywhere, so it allows you to stay at home, or go to work or school.
The disadvantage of this system is that because you are moving around normally all the time the recording is taking place, the quality of the recording is not as good as in cable telemetry. More important, if you have a seizure it will not be captured on video. Instead, you or some observer close to you will have to make an accurate and detailed seizure and activity log — a record of your activity throughout the 24 hours. This can then be correlated with the EEG recording, which has a time clock. It is a tedious and time-consuming process and the results are sometimes difficult to interpret. Inevitably, it does not yield as much information as cable telemetry.
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Some congenital abnormalities (present at birth) are not inherited. For example, the abnormalities in the limbs of the children whose mothers had taken the drug thalidomide during pregnancy are congenital and will not be passed on to their children, as the thalidomide affected the developing cells in the limbs without, (although there continues to be some debate), causing any mutations in the baby’s own ovaries or testes. Other congenital abnormalities may have an inherited basis.
One congenital abnormality relevant to epilepsy is a maldevelopment of blood vessels known as an angioma. The abnormal vessels may be either arterial, venous, or capillary. Sometimes a clot or thrombus forms in one or more of the abnormal vessels, exacerbating the situation. One type of capillary angioma of the brain is associated with a similar malformation of blood vessels in the skin of the upper part of the face—the Sturge-Weber syndrome. Children with this particular combination of angiomatous abnormalities have a high probability of developing seizures.
More common than angiomas as a cause of epilepsy are disorders oi migration of nerve cells during fetal development, so some end up in the wrong place, the wrong layer of the brain, or with the wrong connections. They are congenital abnormalities, but unlike a harelip, for example, externally invisible. The causes of such disorders are not known, but some probably have a genetic basis. This sort of abnormal brain development may cause seizures and fits in the first few weeks or months of life, including infantile spasms (West’s syndrome).
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Tags: Epilepsy