What is an atypical absence seizure?

These seizures are a type of absence seizure that is atypical (a-TIP-i-kul). This means it’s different, unusual, or not typical compared to typical absence seizures, which were previously called petit mal seizures. They are a type of generalized onset seizure, which means they start in both sides of the brain.

The person will stare (just like in absence seizure) but they may be able to respond a bit.

Eye blinking, chewing movements, lip smacking, or slight jerking movements of the lips may occur.

There may be rubbing of the fingers or hands or other small hand movements.

Symptoms of absence seizures can be difficult to pick up in a person with other cognitive or behavioral problems. It may be hard to tell what is due to a seizure or from other behaviors.

These seizures may begin and end gradually. This is different from the sudden start and stop of a typical absence seizure.

Falling during the seizure is also more common than it is during typical absence seizures.

Atypical absence seizures usually last 5 to 30 seconds, most often more than 10 seconds.

Who is at risk for atypical absence seizures?

These seizures generally begin before age 6. Most of the children with this type of seizure have cognitive and developmental problems. They may also have other types of seizures that are hard to control. Many have Lennox-Gastaut syndrome.

What’s it like to have an atypical absence seizure?

When people have atypical absence seizures, you may notice

The person is not fully aware of what is going on around them. For example, they will not notice if someone is talking to them.

If they are talking to someone, they may stop talking in the middle of the sentence.

Atypical absence seizures most often affect school age children. A teacher may want to talk to the parent, because the child is having problems at school.

Atypical absence seizures usually continue into adulthood.

What happens after an atypical absence seizure?

When a single atypical absence seizure ends, the person usually is awake and continues doing whatever they were doing before the seizure.

No first aid is needed during a single seizure.

Sometimes a person may have more than one atypical absence at a time or have groups of seizures. When this happens, the person may be confused or tired afterwards.

Stay with the person after the seizures until they are back to their usual self and safe to be alone.

If a different type of generalized seizure (like an atonic or tonic-clonic seizure) happens after the atypical absence, follow first aid steps for these seizures.

If someone has atypical absence seizures, how often will they happen?

It depends. People who have atypical absence seizures may have just one seizure or they can have several in a row. The seizures could also be spaced out throughout the day.

How are atypical absence seizures diagnosed?

The diagnosis can be difficult if the behavior during seizures is similar to the child's usual behavior.

Descriptions of the events from observers are very important. Take written descriptions to the doctor’s visit. Or try videotaping an event and share that with the doctor.

An EEG (electroencephalogram), which records brain waves, will be done. Many children with these seizures have changes in the EEG when they're not having a seizure that are similar to the seizure pattern. This may make it hard to tell which behaviors are due to seizures and what may be due to other problems.

How are atypical absence seizures treated?

Seizure medicines are used to help prevent atypical absence seizures.

If medicines don’t work satisfactorily, an epilepsy specialist may consider other treatments along with medicines, such as the ketogenic diet.

What should I do if I think my child may have atypical absence seizures?

If you think your child may be having absence seizures, talk to your child’s doctor about your concerns right away. Atypical absence seizures may cause your child to have

Trouble learning at school

Social problems

Problems with behavior

Sudden periods of not responding or paying attention

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