Abstracts

Recently proposed diagnostic criteria for Childhood Absence Epilepsy (CAE) by Loiseau and Panayiotopoulos include additional features to those specified in the current ILAE classification (www.epilepsy.org/ctf/childhood_absence.html). To assess their diagnostic utility, these criteria were analyzed in a large unselected group of children with newly diagnosed CAE. 70 consecutive untreated developmentally normal children presenting with typical absence seizures associated with generalized spike and wave on video-EEG were studied. The clinical and EEG features of all 509 seizures recorded, were analysed independently by two investigators. Using the ILAE classification, children were diagnosed with CAE if they were under 11 years of age, had frequent daily absence seizures and no other seizure type. The additional inclusion and exclusion criteria for CAE as suggested by Loiseau and Panayiotopoulos were applied to the group of children with CAE. Using the ILAE classification, 47 (67%) children had CAE. Applying the newly proposed diagnostic criteria to these 47 children, children were excluded from a diagnosis of CAE for the following criterion: photic stimulation precipitated a seizure (8); age younger than 4 years (4); a seizure lasting less than 4 seconds (15); partial awareness during a seizure (12); a seizure with more than 3 spikes per wave (3); a seizure which showed fragmentation (20); perioral myoclonia or single or arrhythmic myoclonic jerking of limb, head or trunk during a seizure (14). Thus the recently proposed diagnostic criteria eliminated 42 of 47 children with CAE, leaving only 5 (11%) children meeting the recently suggested classification criteria. In a pure unselected group of children with newly diagnosed absence seizures, the proposed diagnostic criteria allow a diagnosis of CAE to be made in only a minority of children previously regarded as having CAE. This suggests that the proposed criteria are overly stringent and fragment the clinical syndrome of CAE. Diagnostic criterion should only be adopted if there is compelling evidence that they are useful clinically or for genetic studies.