Introduction to Seizures :: Nationwide Children's Hospital

Seizures and Epilepsy

Introduction to Seizures and Epilepsy

Has your child had a seizure or been diagnosed with epilepsy? This information will give you a basic understanding of your child’s condition. If you still have questions, be sure to ask your doctor or nurse practitioner at your next appointment.

What is a seizure?

A seizure occurs when the nerve cells in the brain send out sudden, excessive, uncontrolled electrical signals. Everyone’s brain has continuous electrical activity. When something goes wrong with this activity, your child may have a seizure. Seizures can produce a variety of symptoms depending on what part of the brain is involved. Seizures can range from something as simple as a strange feeling in your stomach to uncontrolled rhythmic movements of your entire body, called a convulsion.

About ten percent (10%) of people will have a seizure at some time in their life. Some of those people will develop epilepsy.

What is epilepsy?

Epilepsy is characterized by two (2) or more unprovoked seizures. Once a person has had two (2) seizures which were not provoked by something such as fever, illness, or withdrawal from drugs or alcohol he will be diagnosed with epilepsy. Epilepsy is common. You may not know someone has epilepsy unless you see them have a seizure. Seizures occur in 1.5% of people. More people are living with epilepsy than cerebral palsy, multiple sclerosis, and Parkinson’s disease combined. Each year in the U.S., 45,000 children under the age of 15 will develop epilepsy. Epilepsy is more common in children under the age of five (5) and adults over the age of 65, but can occur in anyone at any time in their life.

Once someone has one seizure, there is about a 50% chance that they will go on to have another seizure. Fifty percent (50%) of those people will have their second seizure within six (6) months and 80% within two (2) years. After having two (2) seizures, most children (80%) will have another seizure within four (4) years. If a child has an abnormal Electroencephalogram (E-LEK-tro-en-SEF-ah-lo-gram), 2 neurological exam, delayed development, or a structural problem with their brain, they are more likely to have further seizures after their first seizure.

How do we know if it was a seizure?

When a child has an unusual event or episode, a seizure may be suspected. A detailed description of what the event looked like is the most important information to help the healthcare team decide if your child had a seizure. Your medical team will probably not see your child have a seizure. However, they usually know what happens in the beginning, middle and end of a seizure. Your description will help your doctor or nurse practitioner determine if the episode is a seizure, and if so, what kind of seizure it is. We understand that seeing your child have a seizure is very scary and you may not remember many details. Write down the details of the seizure as soon as possible after it occurs. It is also important to keep a seizure calendar or record of all of your child’s seizures. Always bring this information with you to your child’s neurology appointments.

The most useful medical test used to diagnose seizures is an Electroencephalogram (E-LEK-tro-en-SEF-ah-lo-gram) or EEG. An EEG records the electrical activity in the brain. An EEG cannot tell us for sure if your child has had a seizure unless he/she has an actual seizure during the test. This rarely occurs. However, if your child has abnormalities in electrical activity even when he is not having a seizure, this tells us that your child may be at increased risk for seizures. This information, along with how you describe the event, can usually help us to determine if your child had a seizure.

If a child has an abnormal EEG it does not indicate they had a seizure or ever will have a seizure. Likewise, if a child has a normal EEG, it does not mean they will never have a seizure. An EEG is just a snapshot of the electrical activity in the brain at that moment in time. Abnormal electrical activity may not show up when the EEG is performed.

What do seizures look like?

There are many different types of seizures. Not everyone falls and shakes when they have a seizure. But not everyone who does fall on the ground and starts shaking is having a seizure. There are many other kinds of problems that can look like seizures. Some things that can be confused for seizures in children include syncope (fainting), breath holding, reflux (spitting up) in babies, and anxiety attacks.

There are two main types of seizures: generalized and partial. One type is not better to have than the other; they are just different. It is helpful to figure out what type of seizure your child has in order to choose the most effective medication.

If your child’s EEG is abnormal it may be able to tell us if the seizures are partial or generalized. Sometimes we can tell what type of seizure your child is having by how you describe the event. Generalized seizures are those that start from both sides of the brain. Partial seizures start in just one part of the brain but may spread to involve the whole brain. This can happen so fast that it is hard to tell they are coming from just one area. Simple partial seizures involve such a small area of the brain that the child may be aware they are having a seizure and can respond and possibly even talk during the seizure. A complex partial seizure involves a larger area of the brain and the child cannot respond and is not aware they are having a seizure. Please refer to the Helping HandTM: Seizure Care and Helping HandTM: Seizures (Partial) for more information.

What causes seizures and epilepsy?

Seizures that are provoked (such as the case with seizures caused by fever) are not considered epilepsy. Brains of children between six (6) months and five (5) years of age are sensitive to illness and fever. When a young child has a fever, he may have a seizure. It is not usually epilepsy if it is just fever related.

When seizures are not brought on by fever or another event, it is an epileptic seizure. In most (about 70%) children who have epilepsy, the cause for the epilepsy is either unknown or genetic. We do not know very much about the genetics of epilepsy but we are learning more about it every day. There are a few genetic tests that can be done for epilepsy but a specific genetic cause cannot be found for most children. The genetics of epilepsy are very complex and there may not be anyone else in the family who has ever had epilepsy.

One of the most common causes of epilepsy in children is a developmental disorder or birth defect. This is the case in about 20% of children with epilepsy. Other causes for epilepsy include head injuries (5%); infection of the brain such as meningitis or encephalitis (4%); stroke (1.5%), and brain tumors (1.5%). Many children get minor bumps to the head and these minor injuries rarely result in epilepsy. Most children who have epilepsy due to a brain injury have had a major head injury and have been in the hospital. Many parents worry when their child has a seizure that he may have a brain tumor. Brain tumors are rarely a cause for seizures in children. They are a much more common cause of seizures in adults.

How do you determine what is causing the epilepsy?

Sometimes an EEG will show us a specific pattern of electrical activity in the brain that can give us clues as to what is causing the epilepsy. We know that some patterns are always associated with genetic causes and occur in children who are otherwise healthy and have no other neurological problems. In those children we often do not need to do any other testing because we know the epilepsy is genetic. There is no blood test for most genetic forms of epilepsy. Other times the EEG may show unusual activity in one area of the brain. If so, we will likely do an MRI (Magnetic Resonance Imaging) of the brain to see if there is any structural problem in that area of the brain. The most common type of structural problem is cortical dysplasia. This is an area in the brain that did not develop correctly and now may be causing seizures. This problem may not cause any other problems until a child has a seizure. These abnormalities do not grow like brain tumors. They have been there since birth and do not change over time. If we are worried that your child has other neurological problems in addition to seizures or has developmental problems for an unknown reason we may order other blood and urine tests.

What is an epilepsy syndrome?

Some children have a very specific pattern on their EEG and a specific type of seizure which may tell us that the child has an epilepsy syndrome. If your child has an epilepsy syndrome this means that we know more about what to expect in relation to your child’s epilepsy. We may be able to tell you what type of seizures we expect your child will have, the age at which seizures usually start, when they might outgrow their seizures, and what medications work the best. Two common epilepsy syndromes in children are Benign Rolandic Epilepsy and Childhood Absence Epilepsy.

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