Cognitive effects of low-dose topiramate monotherapy in epilepsy patients: A 1-year follow-up.

The present study was conducted to evaluate the long-term effects of low-dose topiramate (TPM) monotherapy on the cognitive function of epilepsy patients. Forty-seven epilepsy patients received TPM, with target doses of 50, 75, and 100 mg/day. Cognitive tests were performed twice, at baseline and 1 year after starting medication. Thirty-six patients completed the follow-up neuropsychological tests. After a year of treatment, 16 patients (44%) complained of cognitive problems. Although it improved seizure frequency and EEG abnormalities, TPM had significantly negative effects on the digit span and verbal fluency tests. These cognitive effects were dose-related and significantly improved after withdrawal from TPM and substitution with older antiepileptic drugs. In conclusion, even at a low dose, TPM has long-term, negative effects on working memory and verbal fluency.