Epilepsy is a nervous system disorder that causes seizures. Seizures are temporary changes in brain activity. Doctors categorize and treat different types of epilepsy based on the kinds of seizures they cause.

Absence seizures, sometimes called petit mal seizures, are brief, usually lasting less than 20 seconds. They cause symptoms that may be barely noticeable. People having these seizures may appear like they’re daydreaming or zoning out.

Read on to learn more about absence seizures, including typical symptoms, causes, and treatment.

Absence seizures most commonly affect children between the ages of 4 and 12. They can also occur in adults. Absence seizures tend to cause shorter and milder symptoms than tonic-clonic seizures, also called grand mal seizures.

According to the Epilepsy Foundation, an advocacy group, absence seizures generally last less than 10 to 20 seconds. Typical symptoms include:

  • staring off into space
  • smacking the lips together
  • fluttering eyelids
  • stopping speech in the middle of a sentence
  • making sudden hand movements
  • leaning forward or backward
  • appearing suddenly motionless

Adults may mistake absence seizures in children as misbehaving or being inattentive. A child’s teacher is often the first to notice absence seizure symptoms. The child will appear temporarily absent from their body.

You can often tell if a person is experiencing an absence seizure because they become unaware of their surroundings, touch, and sound. Absence seizures typically occur suddenly and with no warning. This makes taking precautions to protect the person having a seizure important.

Your brain is a complicated organ, and your body relies on it for many things. The nerve cells in your brain send electrical and chemical signals to each other to communicate. Seizures are the result of altered electrical activity in your brain.

During an absence seizure, your brain’s electrical signals may repeat themselves. You may also have altered levels of neurotransmitters, which are the chemical messengers that help brain cells communicate.

Researchers don’t know the specific cause of absence seizures, but there’s a presumed genetic component. The genetics aren’t well understood, but a 2016 research review found that some ion channel coding gene mutations may contribute in some families.

Risk factors for developing absence seizures include:

  • Age. Absence seizures most often occur in children ages 4 to 12. Based on a 2019 study, they peak around ages 6 to 7.
  • Triggers. Hyperventilation or flashing lights may trigger an absence seizure in some people, according to a 2021 review.
  • Gender. In a 2019 study, absence seizures occurred more often in girls than in boys.
  • Family history. A family history of epilepsy has been reported in 41.8 percent of children with juvenile absence epilepsy. Juvenile absence epilepsy is an epileptic syndrome characterized by absence seizures and generalized tonic-clonic seizures.

Everybody can experience seizures differently, but some of the ways people describe experiencing absence seizures include:

  • seeing dark halos and afterimages around objects
  • experiencing a feeling of floating or brain fogginess
  • feeling your mind going blank while remaining conscious
  • being aware of what’s going on but being unable to act
  • hearing echoing voices and experiencing blurry vision
  • experiencing a period of peacefulness

A neurologist, who specializes in diagnosing nervous system disorders, evaluates:

  • symptoms
  • overall health
  • medications
  • preexisting conditions
  • imaging and brain wave scans

They will try to rule out other causes of your symptoms before diagnosing absence seizures. They may order an MRI of your brain. This scan captures detailed views of brain vessels and areas where potential tumors could be.

Another way to diagnose the condition uses bright, flickering lights or hyperventilation to trigger a seizure. During this test, an electroencephalography (EEG) machine measures brain waves to look for any changes to the brain’s functioning.

It can be difficult to tell whether someone is daydreaming or having an absence seizure. Here are some of the distinguishing features to look out for:

DaydreamingAbsence seizure
tends to happen during periods of boredomcan happen at any time, even when physically active
tends to onset more slowlyoften onsets quickly without warning
tends to stop when interrupted, such as if you call their nametypically ends within about 10 to 20 seconds, but can’t be interrupted

Focal onset seizures, or partial seizures, start on one side of your brain. The Epilepsy Foundation says that they’re the most common type of seizure in adults. These seizures are referred to as focal impaired awareness seizures when they cause changes in your level of awareness. Some focal impaired awareness seizures are misdiagnosed as absence seizures.

Some of the key features that are more typical of focal impaired awareness seizures than absence seizures include:

  • less than daily frequency
  • lasting longer than 30 to 45 seconds
  • confusion and sleepiness after seizures
  • aura or strange feeling before the seizure

Antiseizure medications can treat absence seizures. Finding the right medication involves trial and error and can take time. Your doctor may start with low doses of antiseizure medications. They may then adjust the dose based on your results.

Some examples of medications used to treat absence seizure are:

  • ethosuximide (Zarontin)
  • lamotrigine (Lamictal)
  • valproic acid (Depakene, Stavzor)

Warning

Pregnant people or people who are thinking of becoming pregnant shouldn’t take valproic acid because it increases the risk of developmental issues for the fetus.

Those who have absence seizures may wish to wear a medical identification bracelet. This helps others know what to do in case of an emergency. You may also want to educate your loved ones on what to do if a seizure occurs.

Absence seizures typically last less than 10 seconds but can last up to 20 seconds. The person returns to their usual behavior after the seizure. They usually won’t remember the past few moments or the seizure itself.

While absence seizures occur in the brain, they don’t cause brain damage. Absence seizures won’t have any effect on intelligence in most children. Some children may experience learning difficulties because of their lapses in consciousness. Others may think they’re daydreaming or not paying attention.

In most cases, the only long-term effects of an absence seizure occur if the person falls or gets injured. Falls aren’t typical during this type of seizure. A person can experience absence seizures a dozen or more times per day without any negative effects.

Other people are usually the first to notice absence seizures. This is because the person having one is unaware that they’re experiencing a seizure.

Children with absence seizures often outgrow the condition. Absence seizures can continue, however. Some people progress to longer or more intense seizures.

About 57 to 74 percent of children outgrow absence seizures by adolescence. Taking antiseizure medication can usually help to control seizures and avoid social or academic difficulties.

Absence seizures persist past childhood in about 10 to 15 percent of children. Another 10 to 15 percent have persistent absence seizures with either generalized tonic-clonic or myoclonic seizures. About 5 to 15 percent develop juvenile myoclonic epilepsy.

Some activities can be dangerous for people with absence seizures. This is because absence seizures cause a temporary loss of awareness. Driving and swimming during an absence seizure might cause an accident or drowning.

Your doctor may restrict your activity until they’re certain your seizures are under control. Some states also may have laws about how long a person must go without a seizure before getting back on the road.