Childhood absence epilepsy requiring more than one medication for seizure control

Absence epilepsy is the most common primary generalized epilepsy syndrome encountered in pediatric practice. Treatment is pharmacologically specific and usually successful with a single medication. The objective of this study was to identify any clinical or electroencephalographic features at initial presentation in a consecutive cohort of children with absence epilepsy that may be associated with the need for a second medication.

A computerized pediatric neurology database (1991-2007 inclusive) was retrospectively searched for all patients with typical absence seizures, 3 Hz spike and wave on EEG and no apparent symptomatic etiology who were over the age of two years at seizure onset with at least one year of follow-up. All such children were then divided into two groups; a) those requiring a single medication for seizure control (Group 1), and b) those requiring two medications for seizure control despite optimal management with the initial medication as determined by serum drug monitoring (Group 2). Clinical and electrographic features evident at diagnosis were then contrasted between Group 1 and 2.

Seventy-five children with absence seizures were initially identified with 52 meeting the study's inclusion and none of the exclusion criteria. Of these 52 children, 43 required a single medication for seizure control (Group 1), while 9 required two or more medications for seizure control (Group 2). A significant difference (p < 0.05) was apparent between Group 1 and 2 with respect to gender (16/43 males vs 8/9 males) and mean age of diagnosis (8.19 years +/- 3.00 vs 6.06 years +/- 2.22). Age of onset of seizures, interval duration of seizures prior to treatment initiation, duration of seizures, presence of automatisms, family history, presence of co-morbid conditions and EEG findings were not found to be significantly different between the two Groups.

Male gender and an earlier age of diagnosis is associated with the need for two medications for seizure control in children with absence epilepsy. This observation may suggest the need for more intensive early programmatic follow-up for young male children with newly diagnosed absence epilepsy to effect more rapid attainment of seizure control.