The author evaluated a group of 60 children (28 boys and 32 girls) with idiopathic generalized epilepsy which started during adolescence. The group comprises children with absences, myoclonic and tonic- -clonic attacks which started between the age of 9 and 17 years, with a normal intellect, negative neurological and neuroradiological finding and generalized discharges on EEG. The group of juvenile absences comprises 8 children, mean age 13.5 years, with an incidence of epilepsy in the family in 12.5%. In addition to absences 87% children had generalized tonic-clonic seizures, in the EEG 75% children had regular discharges of the spike and slow wave 3Hz, without photosensitivity. Juvenile myoclonic epilepsy was recorded in 19 children, mean age of development of epilepsy 12.5 years, a positive family-history in 5.2 %, in addition to myoclonias 10% children had absences and 52% generalized tonic-clonic seizures. 90% children had in the EEG discharges of multiple spikes and slow wave, photosensitivity was recorded in 36%. In the group of generalized tonic-clonic seizures after awakening comprised 7 children, mean age 14.1 years, a positive case-history was recorded in 14.1%. In the EEG there was an equal number of findings with complexes of spikes and wave and multiple spikes and wave, photosensitivity was not recorded. Among these forms of epilepsy defined by the International Classification of Epilepsies and Epileptic Syndromes (1989) 34 children (56%) could be included. The group of 26 children not included are children with sporadic occurrence of generalized tonic-clonic seizures without an association with arousal. The mean age at the time of development was 11.5 years, a positive family-history was recorded in 19.2 %. EEG findings are similar as in the group of children with generalized seizures after arousal, there is however marked photosensitivity. The seizures are usually (88.6%) provoked by intermittent light or sleep deprivation. Treatment and the subsequent course were similar as in other forms of epilepsy. The group of children with generalized tonic-clonic seizures is a special form of epilepsy during adolescence which can be differentiated from other forms of idiopathic generalized epilepsies.

        Key words: generalized idiopathic epilepsy, classification, adolescence, sporadic generalized tonic-clo-