Absence Seizures

Overview

What is an absence seizure?

Absence seizures are brief seizures that cause a lapse in awareness. They typically start suddenly, without warning, and last a few seconds. They are common in children and are sometimes mistaken for daydreaming or not paying attention. Recovery is immediate.

These seizures are also known by an older term, petit mal seizures. This name is no longer encouraged by the medical community. Most childhood absence seizures can be controlled with medication.

What does an absence seizure look like?

If your child experiences an absence seizure:

  • They may look like they are staring off into space or have a blank stare. Your child has temporarily lost awareness of what’s happening around them.
  • They may suddenly stop all activity — even in the middle of an activity — and will not respond during the seizure. This is especially notable during school or when they are breathing heavily.
  • Their eyes may turn upwards or their eyelids may flutter.

How long do absence seizures last?

Most seizures last between five seconds and 30 seconds, but they can last for a few minutes, although this is less common. The longer the seizure lasts, the more likely it’ll be noticed by others.

Absence seizures may be frequent, 10 to more than 30 times a day. Some children can have hundreds of absence seizures a day.

What happens after an absence seizure ends?

Your child usually continues whatever they were doing before the seizure. They’re usually able to think clearly and are wide awake. However, if more than one seizure happens close together, your child may look or act confused and lose their place in what’s going on around them. For example, during the seizure, they may miss hearing instructions from teachers or what has been said in a conversation.

Do only children get absence seizures?

Although anyone can have absence seizures, they’re more common in children. They’re usually seen in children between 2 and 12 years of age, and most commonly occur in children of early elementary school age, between the ages of 5 and 7.

How common are absence seizures?

Absence seizures occur in about 5 people in every 100,000 of all ages, and in 6 to 8 in every 100,000 children younger than 15 years of age. About 10% of all childhood epilepsies and seizures are absence seizures.

Can you outgrow absence seizures?

There’s a high chance (up to75%) your child will grow out of absence seizures by adolescence. Children who have only absence seizures and not absence seizures combined with other seizure types have the best chance of outgrowing them.

What can trigger absence seizures?

The triggers for absence seizures are the same as for other types of epilepsy.

Triggers include:

  • Lack of sleep.
  • Not taking medications as instructed by your healthcare provider.
  • Emotional stress, worry or excitement.
  • Breathing heavily
  • Sounds, flashing lights, bright sunlight.
  • Withdrawal from benzodiazepines and other central nervous system drugs.
  • Use of medications that make seizures more likely, such as isoniazid (a drug used to treat tuberculosis) or antipsychotics (class of drugs used to treat mental health conditions).
  • Use of alcohol or other drugs.

Symptoms and Causes

What are the symptoms of an absence seizure?

Absence seizure symptoms include:

  • Brief sudden staring spell or “blank stare.”
  • Loss of awareness.
  • Complete stop in activity during the seizure.
  • Occasional eyelid fluttering or nodding of the head or other “automatic” hand or mouth movements.

What causes absence seizures?

Researchers believe genetics plays a role in all generalized epilepsy types, which includes absence seizures. Several genes are thought to be involved. Specific details about inheritance still aren’t known.

What are generalized seizures?

There are two main groups of seizures: generalized seizures and focal seizures. Absence seizures are a type of generalized seizure. These seizures begin with brief abnormal electrical activity that involves both sides of the brain at the same time.

Diagnosis and Tests

How are absence seizures diagnosed?

Your healthcare provider makes the diagnosis of absence epilepsy based on symptoms, a hyperventilation test and results of an electroencephalogram (EEG) test.

Be prepared to describe your child’s symptoms, including what happened before, during and after the event. This information may come from you or other family members or school staff.

Hyperventilating can trigger an absence seizure. To help make the diagnosis, your healthcare provider may want your child to perform this test. If so, your child will be asked to blow repeatedly for more than two minutes.

Your healthcare provider will order an electroencephalogram test. During this test, the electrical activity of their brain is monitored through sensors placed on your child’s scalp. Absence seizures are diagnosed by a particular type of brain wave pattern.

What is an atypical absence seizure?

Healthcare providers define absence seizures as typical or atypical. Atypical seizures are recognized by their own unique EEG pattern and can occur at any age. This seizure type usually starts and ends more slowly and lasts longer (20 seconds or more) than typical absence seizures. Atypical absence seizures also usually cause more muscle movement in a person, such as smacking lips or chewing movements, more eye blinking and rubbing fingers together or other hand motions. Atypical absence seizures usually occur with other seizure types and more often affect children who have a learning disability and severe epilepsy.

Management and Treatment

How are absence seizures treated?

Absence seizures are treated with antiseizure medications. Ethosuximide (Zarontin®) is the preferred medication to treat absence seizures. Other medications that your healthcare provider might try include valproate (Depakene®), lamotrigine (Lamictal®) and topiramate (Topamax®).

Certain types of antiseizure medications, such as phenytoin, carbamazepine, gabapentin, pregabalin and vigabatrin, aren’t usually used to treat absence seizures. These drugs can worsen seizures.

A ketogenic diet may be considered, but good evidence to support its use is lacking. A ketogenic diet may be considered if your child’s absence seizures don’t respond to medication.

What follow-up should be expected if my child has been diagnosed with absence seizures?

A team of healthcare specialists usually manages individuals with epilepsy. Team members may include a neurologist/child neurologist, primary care provider, pharmacist, nurse, dietitian and mental health professional.

Be sure to let your doctors or pharmacist know if your child’s symptoms aren’t controlled or if they experience any adverse reactions. A change in drug dose or type may need to be made. Your neurologist or primary care doctor will monitor blood levels and liver function (depending on the medication used) with occasional blood tests. A dietitian may be consulted if a ketogenic diet is recommended. If your child develops anxiety, depression or stress, a mental health professional may become involved.

Prevention

Can absence seizures be prevented?

Unfortunately, there isn’t a way to prevent absence seizures, since genetics are thought to play a role in their cause.

What activities should my child with absence seizure avoid?

Your child shouldn’t swim, dive or rock climb without supervision. Your child also shouldn’t drive unless seizures are controlled with medication.

Outlook / Prognosis

What can I expect if my child has absence seizure?

Most children respond to treatment with anticonvulsant medication. In most children — up to 75% — absence seizures goes away by their teen years and medications are no longer needed.

Frequently Asked Questions

If the seizures are only brief, do they really need to be treated?

Even though absence seizures occur for a very short period of time, they are not harmless. Your child is experiencing seizure episodes that alter their consciousness. Seizures can interfere with learning (for example, missing what is being taught during seizure episodes), which can impact school performance. Seizures also affect your child’s physical safety, increasing the risk of accidents.

How can I tell the difference between daydreaming and absence seizure in my child?

If your child is daydreaming, attention can be regained immediately when your child is spoken to by you, or a teacher or a friend. Daydreaming usually is brought on by boredom and comes on slowly.

If your child is having an absence seizure, the inattention comes on suddenly, can’t be interrupted and can happen anytime – including during a physical activity. It ends on its own, usually within 20 seconds.

A note from Cleveland Clinic
Absence seizures cause a short-term lapse in awareness. Because they typically last fewer than 20 seconds per episode, and because they’re more common in elementary school-aged children, they may be difficult to detect. In fact, they’re often first discovered by your child’s teachers, by not responding when called upon or by slipping academic performance. The good news is that up to 75% of children who have absence seizures alone outgrow their seizures during their teenage years and no longer require medication.

Last reviewed by a Cleveland Clinic medical professional on 12/15/2021.

References

  • Albuja AC, Murphy PB. Absence Seizure. (https://www.statpearls.com/articlelibrary/viewarticle/28842/) 2020 Nov 21. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. Accessed 12/15/2021.
  • Epilepsy Foundation. Absence Seizures. (https://www.epilepsy.com/learn/types-seizures/absence-seizures) Accessed 12/15/2021.
  • Epilepsy Foundation. 2017 Revised Classification of Seizures. (https://www.epilepsy.com/article/2016/12/2017-revised-classification-seizures) Accessed 12/15/2021.
  • Posner E. Absence seizures in children. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3867171/) BMJ Clin Evid. 2013 Dec 18;2015:0317. Accessed 12/15/2021.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy