Longterm follow-up of childhood epilepsy with absences. I. Epilepsy with absences at onset.

The purpose of the follow-up study was to determine whether modern therapy with ethosuximide and/or valproate with/without phenobarbitone and its derivatives improves the longterm prognosis of absence epilepsy as compared to formerly used treatments. The patient population consisted of 194 cases (88 boys, 106 girls) with spike wave epilepsy starting with absences. In each case the diagnosis was confirmed by clinical observation and the typical EEG pattern. Only those patients were included who could be followed beyond the eighteenth year of life (up to age 45). The sample includes also older patients diagnosed during the fifties, before the present standard therapy was available. Because of the heterogeneity of the material and its selection, the data obtained are not suited to make a general statement about the ultimate prognosis of absences. The results demonstrate the effectiveness of regularly applied modern treatment. 72 out of 194 patients (37%) manifested generalized tonic clonic seizures (gtcs) during the course: 20 of these patients showed only incidental generalized tonic clonic seizures, which were not dependent on therapy. In 52 cases gtcs appeared without relation to precipitating factors. None of these patients received regular standard therapy before onset of gtcs. In 31 cases absence statuses were observed. These patients did not have an unfavourable outcome provided the standard therapy was instituted early and consequently. A change from absence epilepsy into an epilepsy with complex partial seizures sensu strictiori could not be observed. At final investigation 42 of 194 patients still had seizures: 7 with absences, 35 with grand mal with or without absences.(ABSTRACT TRUNCATED AT 250 WORDS)