Absence epilepsy is a condition comprised of absence seizures. These are staring spells, without physical motion, that normally last less than 10 seconds. These look like a staring spell without warning then a return to consciousness. There is no aura. There is little confusion after the symptom. Often, these seizures can be provoked by rapid, deep breathing for 2-3 minutes (hyperventilation). Sometimes eyelid fluttering may be seen during a longer seizure. Absence seizures are more common in children.
The EEG shows a generalized 3 Hz frequency spike and wave complex during the seizure. A routine EEG may record a seizure, since they are common, or the EEG abnormality may be provoked by breathing deeply for a couple of minutes.
There is also subtype called “Atypical Absence” epilepsy. In this condition, seizures last longer than typical absence seizures. They may have associated with motor activity, such clonic, atonic or tonic features, and there are polyspike discharges on the EEG.