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What causes seizures?WWhat causes seizures?What causes seizures?EnglishNeurologyChild (0-12 years);Teen (13-18 years)BrainNervous systemConditions and diseasesCaregivers Adult (19+) EducatorsNA2010-02-04T05:00:00ZElizabeth J. Donner, MD, FRCPC​10.000000000000052.0000000000000552.000000000000Flat ContentHealth A-Z<p>Learn about the causes and types of seizures and the concept of the seizure threshold.</p><p>Electrical activity in the brain is usually carefully balanced. Normally, neurons fire singly or in small groups to accomplish a task and then stop firing. A seizure happens if many neurons fire at once in uncontrolled bursts. This firing results from a combination of factors that interfere with how the brain normally functions.</p><h2>Key points</h2> <ul> <li>A provoked seizure has a direct cause such as a head injury, an infection or low blood sugar.</li> <li>An unprovoked seizure does not have an immediate cause. A child must have two or more unprovoked seizures before epilepsy will be considered.</li> <li>A seizure threshold is a person's likelihood to have a seizure. The higher the threshold, the less likely it is that a seizure will happen. </li> <li>Factors that raise a seizure threshold include getting enough sleep every night and taking anti-epileptic drugs according to instructions. </li></ul>
Qu’est ce qui cause les crises d’épilepsie?QQu’est ce qui cause les crises d’épilepsie?What causes seizures?FrenchNeurologyChild (0-12 years);Teen (13-18 years)BrainNervous systemConditions and diseasesCaregivers Adult (19+) EducatorsNA2010-02-04T05:00:00ZElizabeth J. Donner, MD, FRCPC​10.000000000000052.00000000000000Flat ContentHealth A-Z<p>Apprenez-en davantage sur les causes et les types de crises et sur le concept du seuil épileptogène.</p><p>L’activité électrique à l’intérieur du cerveau est, normalement, soigneusement équilibrée. Les neurones déchargent de façon individuelle ou en petits groupes pour accomplir une tâche, puis cessent de le faire. Une crise se produit si de nombreux neurones déchargent en même temps de manière incontrôlée. Ces décharges dépendent d’une combinaison de facteurs qui entravent le bon fonctionnement du cerveau.</p><ul><li>Les crises provoquées sont le résultat direct d’une blessure à la tête, d’une infection ou de l’hypoglycémie.</li> <li>Les crises non provoquées n’ont pas de cause immédiate. Si un enfant a deux crises non provoquées ou plus, ces crises sont considérées comme des crises d’épilepsie.</li> <li>Le seuil épileptogène indique la probabilité d’apparition d’une crise. Plus le seuil est élevé, moins il est probable qu’une crise se produise.</li> <li>Parmi les facteurs qui peuvent hausser le seuil épileptogène, on note le fait de dormir suffisamment chaque nuit et de prendre des médicaments antiépileptiques selon les instructions.</li></ul>

 

 

What causes seizures?2057.00000000000What causes seizures?What causes seizures?WEnglishNeurologyChild (0-12 years);Teen (13-18 years)BrainNervous systemConditions and diseasesCaregivers Adult (19+) EducatorsNA2010-02-04T05:00:00ZElizabeth J. Donner, MD, FRCPC​10.000000000000052.0000000000000552.000000000000Flat ContentHealth A-Z<p>Learn about the causes and types of seizures and the concept of the seizure threshold.</p><p>Electrical activity in the brain is usually carefully balanced. Normally, neurons fire singly or in small groups to accomplish a task and then stop firing. A seizure happens if many neurons fire at once in uncontrolled bursts. This firing results from a combination of factors that interfere with how the brain normally functions.</p><h2>Key points</h2> <ul> <li>A provoked seizure has a direct cause such as a head injury, an infection or low blood sugar.</li> <li>An unprovoked seizure does not have an immediate cause. A child must have two or more unprovoked seizures before epilepsy will be considered.</li> <li>A seizure threshold is a person's likelihood to have a seizure. The higher the threshold, the less likely it is that a seizure will happen. </li> <li>Factors that raise a seizure threshold include getting enough sleep every night and taking anti-epileptic drugs according to instructions. </li></ul><figure><span class="asset-image-title">What is a seizure?</span> <div class="asset-animation"> src="https://akhpub.aboutkidshealth.ca/Style%20Library/akh/swfanimations/swf.html?swffile=Seizure_what_is_MED_ANI_EN.swf" </div> </figure> <ul><li>Neuron excitation and inhibition become unbalanced; either there is too much excitation, or too little inhibition.</li><li>A small group of neurons begin to fire together.</li><li>Other neurons nearby or throughout the brain also start firing together because of abnormal connections between neurons or groups of neurons - this firing is called hypersynchrony.</li><li>The neurons involved in the seizure send instructions to the parts of the body that they control.</li></ul><h2>Provoked and unprovoked seizures</h2><p>Seizures may be provoked or unprovoked.</p><ul><li>Provoked seizures are the direct, immediate result of a cause such as a head injury, a high <a href="/Article?contentid=30&language=English">fever</a>, an infection, drugs, withdrawal from medication or <a href="/Article?contentid=1726&language=English">low blood sugar</a>. Anybody can have a single seizure under these conditions. Provoked seizures are less likely to happen again and are not considered to be epilepsy.</li><li>When a seizure is not provoked by an immediate, acute cause such as the ones described above, it is called an unprovoked seizure. If a child has two or more unprovoked seizures, they are considered to have epilepsy.</li></ul><h2>Seizure threshold</h2><p>The seizure threshold is not a specific measurement. It is a way of thinking about the balance between neuron excitation and inhibition in the brain. </p><p> <em>Sarah’s seizures are well controlled on anti-epileptic drugs. She has an important test tomorrow. She stays up three hours later than usual to study, and then takes her medication when she goes to bed. The next day, she has a seizure at breakfast.</em> </p><p>Under normal circumstances, Sarah would not have had a seizure, because her medication and her regular sleep schedule keep her seizure threshold high. The combination of taking her medication late and losing three hours of sleep lowered her seizure threshold just enough to trigger a seizure. </p><p>Some factors can lower the seizure threshold of a person with epilepsy, including:</p><ul><li>tiredness or excitement</li><li>illness</li><li>alcohol.</li></ul><p>While one of these things by itself might not be enough to cause a seizure, a combination of them may lower the seizure threshold enough to cause a seizure. Factors such as illness and lack of sleep are sometimes known as seizure triggers. </p><p>Factors that can raise the seizure threshold include:</p><ul><li>getting enough sleep every night</li><li>anti-epileptic drugs (in people with epilepsy).</li></ul><p>This means that a person with<a href="/epilepsy">epilepsy</a> may be able to lower their risk of seizures by getting enough sleep and taking their anti-epileptic drugs as prescribed. This is easier for adults than for children. Because children’s bodies are changing day by day, it can be difficult to find the right balance. ​​</p><h2>Do seizures damage the brain?</h2><p>A great deal of epilepsy research in humans and animals has focused on the question of whether seizures cause brain damage, existing underlying brain damage causes seizures, or a combination of both. Because there are so many different factors involved, including the specific epilepsy syndrome, other health conditions, the age of the child, the age at which epilepsy began, the treatment regimen, and the child’s particular characteristics, this is a difficult question to answer.</p><p>The discussion over whether single, brief seizures cause brain damage continues. It is not clear whether single seizures can cause cell death or if it is the cumulative effect of many seizures that cause damage.</p><p>We know that:</p><ul><li>While children who have multiple seizures over a long period of time are at risk for long-term effects, children who have only one or a few brief seizures in their lives usually do not have long-term consequences.</li><li>In animal studies, seizures lasting more than 30 minutes and frequent, recurrent seizures appear to cause some brain cell death and may affect learning and memory. We don’t yet know how these animal studies translate to the care of children.</li><li>If the child’s epilepsy is caused by underlying abnormalities of the brain, this problem or abnormality may also cause learning and behaviour problems.</li></ul><h2>Can my child die from a seizure?</h2><p>It is very rare for a child to die from a seizure. However, people with epilepsy, particularly symptomatic or cryptogenic epilepsy, do have a higher risk of death than people without epilepsy. The risks vary widely and depend on the individual child; talk to your doctor about your child’s situation. </p><p>There is a higher risk of death if:</p><ul><li>the child has a severe underlying neurological disorder </li><li>the child has prolonged status epilepticus; however, status epilepticus is less likely to cause death in children than in adults </li><li>the child is injured during a seizure, for instance through head injuries, drowning, burns, or suffocation</li></ul><p>In the absence of these factors, the risks to the child are very low. Most of the time, death is related to the underlying cause of the epilepsy. If a child is otherwise in good health, their risk of death is small. Talk to your child's doctor about their specific risks.</p><h2>SUDEP (Sudden Unexplained Death in Epilepsy)</h2><p>SUDEP is defined as death for no obvious reason in a person with epilepsy. It is rare, particularly in children, and difficult to predict. Most commonly, the person is found dead in bed in the morning.</p><p>SUDEP does not always involve a recent seizure. In some cases, there is no evidence that a recent seizure has occurred.</p><p>The risk factors for SUDEP include having frequent generalized convulsive (tonic-clonic) seizures, using multiple anticonvulsant medications, and poor compliance with the medication regime (such as skipping doses). The risk factors for SUDEP in children have not been clearly defined; however, research is ongoing in this area.</p><p>More information about SUDEP and support for families who have been affected is available at SUDEP Aware.</p><h2>Reducing the risks</h2><p>Make sure that your child takes reasonable safety precautions. Like all children, children with epilepsy should never swim or have baths alone and should wear a helmet when doing activities like bicycling, skateboarding, in-line skating, or horseback riding. Finally, make sure that babysitters, teachers, and coaches know what to do if your child has a seizure. </p><p>Most experts believe that the best way to prevent SUDEP is to work with your doctor to prevent seizures using as few medications as possible. People with epilepsy are also encouraged to take medications correctly and identify and minimize seizure triggers.</p>What causes seizures?

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