EEG changes and seizure exacerbation in young children treated with carbamazepine.

Carbamazepine (CBZ) has been reported to exacerbate some seizure types in children. We studied the correlation between CBZ-associated EEG changes and seizure exacerbation in 59 children aged < 6 years treated with CBZ. All patients had EEGs before and after initiation of treatment; initial EEGs were not significantly different among the patients. In 33 children (56%), the subsequent EEGs were either unchanged or improved or demonstrated minor changes (Group I), and excellent to complete seizure control was achieved in 67% of patients. In 26 children (44%), the EEG became significantly more abnormal and was characterized predominantly by new appearance of generalized spike/polyspike-and-wave discharges (group II). The majority of these patients (65%) experienced seizure exacerbation (p < 0.001). For group I, symptomatic partial epilepsy, idiopathic focal epilepsy, and complex febrile seizures were significantly more common; in group II, cryptogenic seizure disorders were more common (p < 0.005). Children in group I were more likely to remain on CBZ or to be weaned from medication after successful treatment, whereas children in group II required additional medication(s) or complete discontinuation of CBZ. Our results suggest that new appearance of generalized paroxysmal discharges after treatment is highly correlated with seizure exacerbation or suboptimal control as well as with adverse outcome. Conversely, absence of significant EEG deterioration on CBZ is usually associated with good seizure control.