Abstracts

RATIONALE: To determine spontaneous fluctuations of subclinical epileptiform discharges (SED) and to evaluate the effect of lamotrigine on SED in children with well-controlled epilepsy.
METHODS: Sixty-one patients (aged 7-17 years) were included in a double blind, placebo-controlled, cross-over study with lamotrigine or placebo added on to the current AED regime for 12 weeks respectively, 48 patients completed the study. Prolonged ambulatory EEG recordings were taken during baseline, placebo and drug phases. The amount of SED was compared between baseline and placebo to estimate spontaneous fluctuations and between placebo and lamotrigine to estimate the effect of the drug.
RESULTS: We detected SED in 42 out of 61 (69%) children with well-controlled epilepsy. There were considerable inter- and intraindividual fluctuations of discharges in long-time ambulatory recordings with more and longer discharges during baseline compared to placebo (n.s.). Lamotrigine reduced the duration of SEDs per hour (p[lt]0.05), but not the total number of SEDs per hour. Twenty-three out of 36 (64%) patients with SED showed a reduction in the duration of discharges during the lamotrigine phase compared to placebo by a mean of 69% (range: 13-100%).
CONCLUSIONS: In children with well-controlled epilepsy lamotrigine may not be as effective in reducing SEDs as in patients with drug resistant epilepsy. Inter- and intra-individual variations of SED make it difficult to evaluate the effect of antiepileptic drugs on discharges even if prolonged EEG recordings are used.
Support: This study was supported by the Fund for Epilepsy and Glaxo-Wellcome.
Disclosure: Grant - Double-blind, placebo controlled cross over study of the effect of lamotrigine, supported by Glaxo-Wellcome.