Absence seizures (AS) are episodes of temporary loss of consciousness tat may be accompanied by automatism, changes in postural tone mild clonic components or autonomic phenomena. AS are part of several epileptic syndromes.Our study was done on a series of 25 patients with typical AS diagnosed as having CAB or JAB, divided into two groups:controlled and symptomatic. We carried out detailed clinical histoiy, IQ and video EEG monitoring, during which the patients was asked to perform hyperventilation wit breath counting and 14 slept so we could also study the sleep BEG record.The video-BEG revealed the exact clinical and BEG characteristics in each patient and permitted us to compare both groups. We found that AS detection and description obtained by video-BEG monitoring systems was superior than tat obtained from the clinical history alone. Wit this method we found clinical and electrophysiological differences between the patients of both groups and also between those with CAB and JAB.