Absence Seizures

Medically Reviewed by Dr.K on 8 March 2021

What Is an Absence Seizure?

Absence seizures, previously known as “petit mal” seizures, are caused by intense abnormal electrical activity within the brain. Brain nerve cells, neurones, behave normally by firing electrical signals to each other. This pathway is defective in a person suffering with seizures. These seizures may affect only one part, or multiple parts of the brain – known as generalised seizures. Absence seizures are categorised as generalised seizures.

Absence seizures typically last from 10 to 30 seconds at a time; occurring infrequently or as common as many times per hour. It commonly affects children between 5 to 15 years olds. Typical hallmark symptoms that parents, friends or teachers often notice is that the child or teenager abruptly stops whatever it is that they were doing, like walking, talking, playing, and appears to blankly stare into space, “zoning out”. Children can occasionally harm themselves in the process, for instance by falling or collapsing. Once the episode is over, the child has no memory of the event, and will fully recover with no residual effects like confusion or memory loss.

In a developing child, these episodes can interfere with normal development and learning. 25% of patients suffering from absence seizures can proceed to develop another type of generalised seizure known as tonic-clonic seizures, previously known as “grand mal” seizures. Most children affected by absence seizures will eventually outgrow them.

The exact underlying cause for absence seizures is still unknown, however, genetics may play a contributing factor.