PURPOSE: Juvenile myoclonic epilepsy, juvenile absence epilepsy, and epilepsy wth generalized tonic clonic seizure (GTCS) on awakening are the three syndromes of idiopathic generalized epilepsy of adolescent onset currently included in the classification of epilepsy syndromes of the International League Against Epilepsy (ILAE). Although they differ in their predominant seizure types, the syndromes share several seizure types. Also, there are no unique electrophysiologic or genetic markers. The question of phenotypic overlap and purity have arison. METHODS: We diagnosed 60 patients as idiopathic generalized epilepsy in Seoul National University Children's Hospital from August 1987 to June 1993 were analyzed in aspects of seizure types, electroencephalographic findings and follow up results. Their onset age of seizure was over 8 year old and the follow-up period was minimum 3 year. RESULTS: 1) seizure types : Four groups were defined by seizure type. The group with absence but not myoclonic (group A) were 19 cases (31.7%) and the group with myoclonic but not absence (group B), 12 cases (20.0%), the group with absence and myoclnic (Group C), 4cases (6.7%), and the group with GTCS only (Group D), 25 cases (41.6%). There was a tendency in that absence begins earlier and myoclonic seizure later in each group. 2) epilepsy syndromes : We could classify as 20 cases (33.3%) of jevenile absence epilepsy, 15 cases (15%) of jevenile myoclonic epilepsy, 5 cases (8.4%) of epilepsy with generalized tonic clonic on awakening, and 20 cases (33.3%) of isolated generalized tonic clonic seizure. 3) EEG characteristics by seizure type : 3-4Hz generalized bursts were most frequent in group A (p<0.05) and polyspike discharges were more frequent in group B than group A (p<0.05). The response to photic stimulation were more frequently observed in group B than group A. There was no significant differences in response to hyperventilation between group A and B. CONCLUSION: To define the combination of seizure types occurred in intervals make easy to approach the diagnosis and treatment of idiopathic generalized epilepsy syndromes. We found that the current classification does not include all patients such as isolated generalized tonic clonic seizure in this study. We can expect information from the fields of molecular genetics and neuroimaging to help to define the etiologic basis of many epilepsies and perhaps to refine the present system of classification, more etiologically oriented and disease-specifically.
Adolescent ; Age of Onset ; Child ; Classification ; Diagnosis ; Electroencephalography* ; Epilepsies, Myoclonic ; Epilepsy ; Epilepsy, Absence ; Epilepsy, Generalized* ; Follow-Up Studies ; Genetic Markers ; Humans ; Hyperventilation ; Molecular Biology ; Myoclonic Epilepsy, Juvenile ; Neuroimaging ; Photic Stimulation ; Seizures* ; Seoul

PURPOSE: Positive ratio of routine EEG in adult epilepsy was widely known, but small number was reported in child epilepsy. Thus, we studied the difference of positive ratios between ages. METHODS: We reviewed the clinical records of 756 patients, who visited the pediatric neurology clinic with more than 2 afebrile seizures except neonatal seizures, from March 1997 to December 2004. Excluded were children with previous history of antiepileptic medication or failure of EEG. Clinical aspects and EEG findings of left 609 patients were evaluated retrospectively. RESULTS: Median age of EEG examination was 7.0 years (range, 3 months to 19.8 years) and male was 339. Number of child under 2 years was 112, 2-4 was 96, 5-9 was 233, 10-14 was 160 and over 15 was 8. All 279 positive past history was known in 222 persons, 98 of them had previous febrile seizures, 37 had CP or MR, 11 had neonatal seizures, 11 had birth asphyxia, 28 was prematurity. Waking EEG was checked in 398, sleep EEG in 547. Abnormal findings were found in 443 (72.7%). Definite epileptiform discharges were found in 388 patients (63.7%), suspicious spike discharges in 37 (6.2%). Patients under 2 years had 50.0% positive ratio of epileptiform discharges, 2-4 had 62.5%, 5-9 had 85.8%, 10-14 had 66.3% and over 15 had 37.5%. CONCLUSIONS: High positive ratio of routine EEG was found in child epilepsy, thus routine EEG seems to be very useful for the first diagnostic examination in child epilepsy.
Adult ; Asphyxia ; Child* ; Electroencephalography* ; Epilepsy* ; Humans ; Male ; Neurology ; Parturition ; Retrospective Studies ; Seizures ; Seizures, Febrile