Typically, this type of seizure lasts between 10 and 30 seconds. The person, most often a child aged 5 to 15, abruptly stops whatever he's doing (talking, walking) and appears to "stare into space." Absence seizures rarely cause a true convulsion in which the person falls down or collapses. Despite briefly losing consciousness, the person recovers fully with no lingering confusion or other ill effects. These "spells" may occur infrequently or several times per hour. In children, absence seizures may interfere with learning and are often misinterpreted as daydreaming or inattention.
Based on community-based studies6,12,32 proportions (%) of presumed identified causes of epilepsy are the following: cerebrovascular disease 11−21%, trauma 2−6%, tumours 4−7%, infection 0−3%, and idiopathic 54−65%. Epilepsy syndromes are classified according to the ILAE classification37 which is based on age, clinical semiology and electrophysiological findings. However many cases in epidemiological studies are unclassifiable according to the current classification.