Objectives: The aim of this study was to investigate the effects of topiramate (TPM) on cognitive function, specifically language, in patients with epilepsy, and to determine whether a specifically designed neuropsychological test battery can show such effects.

Method: Twenty patients taking TPM, 25 epilepsy controls (taking medication other than TPM) and 25 healthy controls were recruited. We used a specific neuropsychological battery, including measures of visual and verbal memory, attention, fluency and comprehension. Separate one way between group ANOVAs were performed for each neuropsychological measure.

Results: Bonferroni comparisons revealed that the TPM group performed significantly worse than epilepsy controls on digits forward (p<0.001), digits backward (p<0.05), controlled oral word association (COWA) (p<0.05) and token test (p<0.05). The TPM group also needed more multiple choice cues in the Boston naming test (p<0.05).

Conclusions: The present study indicates that 15% of the sample tested had impaired language abilities and raises interesting questions regarding the nature of this effect. Furthermore, we have identified some short neuropsychological tasks that can be performed in routine clinical situations that can reliably identify patients who have negative linguistic effects of TPM.