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. About a quarter of people who have absence seizures will develop another type of generalized seizure called tonic-clonic seizures (formerly called ''grand mal'' seizures). The vast majority of children, however, will outgrow them.
Approximately 60% of all epilepsies are idiopathic or cryptogenic. Almost any type of brain pathology can cause seizures/epilepsy. Cerebrovascular disease is the most commonly identified cause among adults, while perinatal insults seem to be most common among children. The etiology of seizures is multifactorial in any given individual and is best thought of as an interaction between genetically determined seizure thresholds, underlying predisposing pathologies or metabolic derangements and acute precipitating factors.