Frontal-onset absences in children: associated with worse outcome? A replication study.

We studied the clinical and electroencephalographic features in 30 children who were diagnosed with childhood absence epilepsy. According to their EEG pattern we divided the 30 children into two groups: group A: 11 children with classical absences whose ictal EEG showed primary generalized spikes and waves and group B: 19 children with frontal onset of the EEG epileptic abnormalities ('frontal group'). In the frontal group, more frequently complex absences were seen. Although the majority of children responded very well to valproate monotherapy, ethosuximide has to be added in 3 children of the frontal group to achieve seizure freedom. In the frontal group, also more learning and behavioural problems were encountered. This study largely confirms a previous study of Lagae et al. [Lagae L, Pauwels J, Monte B, Verhelle J, Vervisch J. Frontal absences in children. Eur J Pediatr Neurol 2001;5:243-251]. It seems that frontal onset absences constitute a specific subtype within the childhood absence epilepsies.