Absence seizures involve brief and sudden loss of consciousness. They are more common in children than adults.
A person with an absence seizure appears to stare into space for a few seconds. Then there is a quick return to a normal level of vigilance. This type of seizure does not usually result in physical injury.
Absence seizures can usually be controlled with anti-seizure medication. Some children who have it develop other seizures too. Many children overcome absence crises in adolescence.
A sign of a simple absence seizure is a blank look, which can be mistaken for a lack of attention, which lasts about 10 seconds, although it can last up to 20 seconds without confusion, headaches, or drowsiness. Signs and symptoms of seizures when absent are:
Abrupt stop in motion without falling
A touch of lips
The eyelids float
Small movements of both hands
Many children appear to be genetically predisposed to absence seizures.
Usually, seizures are caused by abnormal electrical impulses from nerve cells (neurons) in the brain. Nerve cells in the brain usually send electrical and chemical signals through the synapses that connect them.
In people with seizures, the normal electrical activity of the brain is altered. During an absence seizure, these electrical signals repeat over and over in a three-second pattern.
People with seizures may also have altered amounts of chemical messengers that help nerve cells communicate with one another (neurotransmitters).
Some factors are common in children with absenteeism, including:
Age. Absence seizures are more common in children between the ages of 4 and 14.
Sex. Absence seizures are more common in girls.
Family members who have seizures. Almost half of children with absenteeism have a close relative who has seizures.