Comparison of the effects of vigabatrin, lamotrigine, and topiramate on quantitative EEGs in patients with epilepsy

Information on the effects of newer antiepileptic drugs (AEDs) on the elect roencephalogram (EEG) is sparse and contradictory. Quantitative EEG (qEEG) provides a method of estimating the effects of drugs on the central nervous system. Twenty-three adult patients with difficult-to-control complex part ial seizures, with or without secondary generalization, participated in an add-on study with one of three newer AEDs: vigabatrin (n = 10), lamotrigine (n = 6), and topiramate (n = 7). Frequency analysis and topographic mappin g of awake EEGs before and during treatment with the drug were compared. St atistical analysis was performed using 2-way analysis of variance (ANOVA) w ith repeated measures. Vigabatrin administration was followed by a diffuse decrease in the absolute alpha (p < 0.05) and beta (p < 0.02) activities an d a decrease in the absolute theta in the frontal and parieto-occipital reg ions (p < 0.03). Lamotrigine caused a significant diffuse increase in the f aster frequencies (relative alpha p < 0.04 and relative beta p < 0.02), and decrease in the slower activities (relative theta in the posterior head re gions p < 0.03 and relative delta diffusely p < 0.05). Topiramate increased the absolute beta (p < 0.05) and theta (p < 0.02) activities diffusely and decreased the relative alpha activity over the left hemisphere (p < 0.03). The different effect profiles of the newer AEDs on the electrical brain ac tivity may reflect their different mechanisms of action.