Absence Seizure

Symptoms

Absence seizures cause brief and sudden lapses in awareness that usually last only a few seconds. These seizures are more common in children and often go unnoticed because they are short and do not involve dramatic movements.

A typical absence seizure may cause a child to suddenly stop what they are doing and stare blankly into space. The episode usually lasts about 10 seconds but can extend up to 30 seconds. After the seizure ends, the person quickly returns to normal alertness without confusion, headache, or drowsiness.

Symptoms of absence seizures may include:

• Sudden pause in activity without falling

• Blank or vacant stare

• Lip smacking

• Rapid eyelid fluttering

• Chewing motions

• Rubbing fingers together

• Small, repetitive movements of both hands

After the seizure, there is usually no memory of what happened. If the seizure lasts longer, the person may notice that time has passed. Some children experience multiple absence seizures each day, which can interfere with learning, school performance, and daily activities.

Because these seizures are brief, adults may not notice them right away. A decline in school performance or difficulty paying attention may be the first sign. Teachers may report that the child appears distracted, unfocused, or frequently daydreaming.

Causes

Absence seizures are most often linked to genetic factors. In many cases, children with absence seizures have a family history of seizures or epilepsy.

Seizures occur due to abnormal electrical activity in the brain. Normally, nerve cells called neurons communicate through controlled electrical and chemical signals. During an absence seizure, there is a sudden burst of abnormal electrical impulses that repeat in a regular pattern, typically about three times per second.

This repetitive electrical activity disrupts normal brain function for a short period, leading to the brief loss of awareness seen in absence seizures.

In addition to electrical changes, people with seizures may have altered levels of chemical messengers in the brain called neurotransmitters. These chemicals help nerve cells communicate with each other. When their balance is disrupted, it can increase the likelihood of seizures.

Although absence seizures usually begin in childhood, their exact trigger is not always clear. Many children eventually outgrow them during their teenage years, though some may go on to develop other types of seizures later in life.