Mayo Clinic Health Library

Absence seizure (petit mal seizure)

Updated: 06-23-2011

Definition

Absence seizure — also known as petit mal — involves a brief, sudden lapse of consciousness. Absence seizures are more common in children than adults. Someone having an absence seizure may look like he or she is staring into space for a few seconds.

Compared with other types of epileptic seizures, absence seizures appear mild. But they can be dangerous. Children with a history of absence seizure must be supervised carefully while swimming or bathing because of the danger of drowning. Teens and adults may be restricted from driving and other potentially hazardous activities.

Absence seizures usually can be controlled with anti-seizure medications. Some children who have absence seizures also have grand mal seizures. Many children outgrow absence seizures in their teen years.

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Symptoms

Signs of absence seizures include:

  • Vacant stare
  • Absence of motion without falling
  • Lip smacking
  • Eyelid flutters
  • Chewing motions
  • Hand movements
  • Small movements of both arms

Absence seizures last only a few seconds. Full recovery is almost instantaneous. Afterward, there's no confusion, but also no memory of the incident. Some people experience dozens of these episodes each day, which interferes with their performance at school or work.

Children who are walking or doing other complex tasks during a seizure probably won't fall, though they'll be unaware.

Absence seizures in a child may occur for some time before an adult notices them, because they're so brief. A noticeable decline in a child's learning ability may be the first sign of this disorder. Teachers may comment about a child's inability to pay attention.

When to see a doctor
Contact your doctor:

  • The first time you notice a seizure
  • If you have a new type of seizure

Seek immediate medical attention:

  • If you observe prolonged automatic behaviors — activities such as eating or moving without awareness — or prolonged confusion, possible symptoms of a condition called absence status epilepticus
  • After any seizure lasting more than five minutes
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Causes

Often, no underlying cause can be found for absence seizures. Many children appear to have a genetic predisposition to them. Sometimes hyperventilation can trigger an absence seizure.

In general, seizures are caused by abnormal nerve cell (neuron) activity in the brain. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells. In people who have seizures, the brain's usual electrical activity is altered. During an absence seizure, these electrical signals repeat themselves over and over in a three-second pattern.

People who have seizures may also have altered levels of neurotransmitters, which are the chemical messengers that help the nerve cells communicate with one another.

This type of seizure may be more prevalent in children. Many children gradually outgrow absence seizures over months to years.

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Complications

While most children outgrow absence seizures, some people may find that they are:

  • Experiencing these types of seizures throughout life
  • Eventually experiencing full convulsions (grand mal or generalized tonic-clonic seizures)

Other complications can include:

  • Learning difficulties
  • Absence status epilepticus, a condition in which seizure behavior lasts longer than a few minutes
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Preparing for your appointment

You're likely to start by seeing your family doctor or a general practitioner. However, you or your child will probably be referred to a doctor who specializes in nervous system disorders (neurologist).

It's good to prepare for your appointment. Here's some information to help you get ready for your appointment, and to know what to expect from your doctor.

What you can do

  • Write down any symptoms you or your child is experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Make a list of all medications, vitamins or supplements you or your child takes.
  • Write down questions to ask the doctor.

Preparing a list of questions will help you make the most of your time with your doctor. For absence seizure, some basic questions to ask your doctor include:

  • What's the most likely cause of these symptoms?
  • Are there other possible causes?
  • What kinds of tests are needed? Do these tests require special preparation?
  • Is this condition temporary or long lasting?
  • What treatments are available and which do you recommend?
  • What types of side effects can I expect from treatment?
  • Are there any alternatives to the primary approach you're suggesting?
  • Are there any activity restrictions?
  • Is there a generic alternative to the medicine you're prescribing?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend?
  • Can my child also develop the grand mal type of seizure?
  • How long will my child need to take medication?
  • Can my child participate in physical activities, such as soccer, football and swimming?

Don't hesitate to ask any other questions that occur to you.

What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:

  • When did you or your child begin experiencing symptoms?
  • How often have the symptoms occurred?
  • Can you describe a typical seizure?
  • How long do the seizures last?
  • Are you or your child aware of what happened?
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Tests and diagnosis

Some children experience episodes that resemble absence seizures, but aren't seizures. Such episodes usually can be interrupted by calling the child's name or by touching his or her shoulder. True absence seizures, on the other hand, can't be interrupted by voice or touch. Absence seizures may occur in the middle of a child's conversation or physical activity.

Your doctor will ask for a detailed description of the seizures. Blood tests can help rule out other potential causes of seizures, such as a chemical imbalance or the presence of toxic substances. Other tests may include:

  • Electroencephalography (EEG). This painless procedure measures waves of electrical activity in the brain. Brain waves are transmitted to the EEG machine via small electrodes attached to the scalp with paste or an elastic cap. Your child may be asked to hyperventilate or look at flickering lights, an attempt to provoke a seizure. During a seizure, the pattern on the EEG is different from the normal pattern.
  • Brain scans. Tests such as magnetic resonance imaging (MRI) can produce detailed images of the brain, which can help rule out other types of problems, such as a stroke or a brain tumor. This test is not painful, but your child will need to hold still for long periods of time. Talk with your doctor about the possible use of sedation, especially for young children.
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Treatments and drugs

Many medications can effectively eliminate absence seizures or reduce the number. Finding the right medication and dosage can be challenging, requiring a period of trial and error. Taking the medications on a regular schedule is crucial to maintaining proper drug levels in the blood.

Often, the first drug prescribed for absence seizures is ethosuximide (Zarontin). However, other medications, such as valproic acid (Depakene, Stavzor) and lamotrigine (Lamictal), also are effective at controlling seizures. Your doctor likely will start at the lowest dose possible and increase the dosage as needed to control the seizures. Most children can discontinue anti-seizure medications, under a doctor's supervision, after they've been seizure-free for two years.

The drug Lamictal has been linked to an increased risk of aseptic meningitis, an inflammation of the protective membranes that cover the brain and spinal cord that's similar to bacterial meningitis.

Women who need treatment for absence seizures are advised against using valproic acid while trying to conceive or during pregnancy, because the drug has been associated with higher risk of birth defects in babies. Women who can't achieve seizure control on any other medication need to discuss potential risks with their doctors.

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Lifestyle and home remedies

A person with absence seizures may elect to wear a medical bracelet for identification for emergency medical reasons. The bracelet should state whom to contact in an emergency and what medications you use. It's also a good idea to let teachers, coaches and child care workers know about the seizures and tell them what to do in an emergency.

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Coping and support

Even after they've been controlled with medication, seizures may affect areas of your child's life, such as attention span and learning. Your child will require close supervision for activities such as swimming. He or she will have to be seizure-free for reasonable lengths of time (intervals vary from state to state) before being able to drive.

You may find it helpful to talk with other people who are in the same situation you are. Besides offering support, they also may have advice or tips for coping that you haven't considered. The Epilepsy Foundation has a network of support groups, as well as online forums for teens and adults who have seizures and parents of children who have seizures. You can call The Epilepsy Foundation at 800-332-1000 or visit its website. Also, your doctor may know of support groups in your area.

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