Physiologic Effects of Topiramate on Cognition

Data generated from this pilot project will be used to support a larger, NIH funded study to investigate the physiologic mechanisms associated with the cognitive side effects of a commonly prescribed antiepileptic drug (AED), topiramate (TPM). This study will provide pilot data to 1) demonstrate the viability of using quantitative electroencephalogram (EEG) to examining physiological effects of AEDs as they relate to language function, and 2) perform formal power estimate calculations in support of a longer-term connectivity study using stochastic modeling techniques including power, coherence, and Granger causality metrics to analyze AED effects on quantitative EEG. Traditionally, the cognitive side effects of AEDs have been considered a byproduct of decreased neuronal excitation associated with medical therapy, although recent data suggests that this may not be true for some newer medications, such as TPM. The proposed experiments will employ quantitative EEG to investigate the effects of topiramate on neuronal network connectivity and pharmacokinetic/pharmacogenetic relationships in order to explore individual physiological responses. Topiramate is selected because of its relatively unique effects on generative verbal fluency, but unlike older AEDs, TPM is associated with little EEG change. The investigators will compare the effects of TPM to baseline and an inactive placebo in a randomized double blind crossover design.