SEIZURE OVERVIEW

The brain contains billions of neurons (nerve cells) that create and receive electrical impulses. Electrical impulses allow neurons to communicate with one another. When there is abnormal and excessive electrical activity in the brain, a seizure occurs. This causes changes in awareness, behavior, and/or abnormal movement. Fortunately, this activity usually lasts only a few seconds to minutes.

Seizures are frightening to watch, but children rarely suffer long-term harm as a result of a seizure. Seizure in children change frequently. Since seizures arise in the brain, and a child's brain is growing and changing, the seizures can change in frequency, intensity, duration, and type. Fortunately, most seizures can be controlled with medication, and the risk of seizures often declines as a child grows older.

This article will discuss the most common types of seizures and tests used in children who have seizures. Articles about seizure treatment and febrile seizures are available separately. (See "Patient information: Treatment of seizures in children" and "Patient information: Febrile seizures".)

SEIZURES VERSUS EPILESPY

Epilepsy is not a specific disease, but rather a tendency to have recurrent seizures over a period of time. Seizures that occur when a child has a fever, head injury, or after taking drugs often do not recur and are not considered epilepsy. In addition, what appears to be a seizure may actually be something else (eg, breath holding spell). Having one seizure does not mean that a child has epilepsy. Many clinicians require a child to have more than one seizure before diagnosing epilepsy.

TYPES OF SEIZURE

Seizures have many forms and symptoms can be mild or severe. Seizures are classified according to the child's appearance or behavior during the seizure, and the pattern of electrical activity in the brain, as measured by a test called an electroencephalogram (EEG). (See 'Electroencephalogram' below.)

One of the most common seizure types is a convulsion. This may be called a "tonic clonic" or "grand mal" seizure. In this type of seizure, the child loses consciousness and may stiffen and have jerking muscle movements. During the muscle-stiffening, the child may bite their tongue, causing bleeding or frothing at the mouth.

Other seizure types are less dramatic. Shaking movements may be isolated to one arm or part of the face. Alternatively, the child may suddenly stop responding and stare for a few seconds, sometimes with chewing motions or smacking the lips. These may be called simple partial or complex partial seizures depending on whether the child remains aware.

Seizures may also cause "sensations" that only the child feels. As an example, one type of seizure can cause stomach discomfort, fear, or an unpleasant smell. These feelings are simple partial seizures, commonly referred to as auras. A child usually experiences the same symptoms with each seizure aura. Sometimes, a seizure aura can occur before a convulsive seizure. (See "Overview of the classification, etiology, and clinical features of pediatric seizures and epilepsy".)

After a seizure (postictal state) — With some types of seizures, the child may appear to be awake during the seizure, but is actually unaware and will have no memory of the event.

The period following a seizure is called the postictal state. During this time, the child may be confused and tired, and may develop a throbbing headache. This period usually lasts a few minutes, although it can last for several hours or even days.

In some children, the postictal period comes with certain limitations. For example, the child may experience mild to severe weakness in a hand, arm, or leg. This is referred to as Todd's paralysis, and it usually resolves over several minutes.

Other people have difficulty speaking or experience temporary (partial) vision loss or other types of sensory loss. These can be important clues about the type of seizure and the part of the brain that was affected during the seizure.

SEIZURE TESTING

Determining the type of seizure helps determine what testing is needed and which treatments are most likely to be effective. (See "Clinical and laboratory diagnosis of seizures in infants and children".)

Medical and seizure history — Parents can keep a log book of what they observe during a child's seizures, which can be shared with the child's healthcare provider. Questions to consider after a child's seizure are listed in the table (table 1).

Physical examination — A complete physical examination is important in the process of evaluating a child with seizures. This can be performed by the child's usual healthcare provider (eg, general pediatrician or family practitioner). A neurologist (physician specializing in the brain) may be consulted.

Electroencephalogram — An electroencephalogram (EEG) is a test that measures the electrical activity in the brain. It is performed to search for abnormal electrical activity that is commonly associated with seizures and epilepsy and allows for a clearer understanding of where and why seizures occur. Even if a child does not have a seizure during EEG monitoring, important information can be gained.

EEGs are not painful, and there is no risk of being shocked or harmed by the test. Most children will require EEG monitoring while sleeping and while awake. Parents may be asked to keep their child awake for some part of the night (eg, put the child to bed late, awaken early, prevent sleeping during drive to test). The child should not drink or eat anything with caffeine before the EEG (eg, soda, coffee, tea), and the child's hair should be washed the night before the test.

Before the test, the EEG technologist will measure the child's head and make small marks on the skin with a pen. Approximately twenty wires will be attached to the child's head and face with glue or paste (this will wash out after testing, (figure 1). The child will be asked to lie still and try to sleep, and the technologist and parent can remain in the room with the child during testing. During the EEG testing, the child may be asked to breathe quickly (hyperventilate) or to watch a strobe light. This can provide important additional information for the physician. A typical EEG takes approximately one hour. If the child is unable to sleep, a mild sedative may be given.

After the test is completed, the wires will be removed. A neurologist will interpret the results of the EEG and communicate these results with the child's healthcare provider. A repeat EEG or more prolonged EEG with video recording may be needed.

Other tests — Some children will need to have further testing. These tests may include computed tomography (CT) scans or magnetic resonance imaging (MRI), which provide pictures of of the brain. These tests are not painful, but MRI requires that the child lie very still for up to one hour; most children who are less than five years old are sedated for an MRI because any movement can blur the pictures.

Blood tests may also be recommended. These provide information about the child's chromosomes and the level of chemicals and substances normally found in blood. A lumbar puncture (also known as a spinal tap) may be recommended for some children who have a seizure during a high fever or who may have a metabolic disorder. The test involves inserting a needle into the low back to remove a small amount of fluid (cerebrospinal fluid or CSF) from around the spinal cord. (See "Patient information: Febrile seizures".)

PROGNOSIS

The long-term impact of seizures is small for most children, especially if there are no underlying abnormalities in the child's brain. Many children with epilepsy have normal development and a good chance for a normal life. Some children with seizures will have difficulties with growth or development. This risk depends on the underlying type of epilepsy or cause of seizures.

SEIZURE TREATMENT

The treatment options for children with seizures is discussed separately. (See "Patient information: Treatment of seizures in children".)

WHERE TO GET MORE INFORMATION

Your child's healthcare provider is the best source of information for questions and concerns related to your child's medical problem.

This article will be updated as needed every four months on our web site (www.uptodate.com/patients).

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information

Patient information: Treatment of seizures in children
Patient information: Febrile seizures

Professional level information

Clinical and laboratory diagnosis of seizures in infants and children
Clinical features and complications of status epilepticus in children
Clinical features and diagnosis of infantile spasms
Clinical features and electrodiagnosis of neonatal seizures
Epilepsy syndromes in children
Etiology and prognosis of neonatal seizures
Febrile seizures
Management and prognosis of infantile spasms
Management of status epilepticus in children
Neonatal epileptic syndromes
Overview of the classification, etiology, and clinical features of pediatric seizures and epilepsy
Pharmacology of antiepileptic drugs
Treatment of neonatal seizures
Treatment of seizures and epileptic syndromes in children

The following organizations also provide reliable health information.

• The Epilepsy Foundation

      (www.epilepsyfoundation.org/)

• National Institute of Neurological Disorders and Stroke

      (www.ninds.nih.gov/disorders/epilepsy/detail_epilepsy.htm)

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/epilepsy.html)

• Epilepsy Therapy Development Project

      (www.epilepsy.com)

• International League Against Epilepsy and the International Bureau for Epilepsy

      (www.epilepsy.org)

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