Effects of phenytoin and valproic acid on cognitive functions of Thai epileptic patients: a pilot study

Effects of valproic acid (VPA) and phenytoin (PHT), as monotherapy, on cognitive functions and mood of Thai epileptic patients were investigated. Thai Mental Status Examination (TMSE) and Alcohol Use Disorder Identification Test (AUDIT) were used to screen for eligible subjects. Cognitive performance was assessed by neuropsychological tests including Stroop Color Word Test (SCWT), Wechsler Abbreviated Scale of Intelligence (WASI) test, Profiles of Mood States (POMS) and Adverse Event Profiles (AEP). Thirty epileptic patients, 15 taking PHT and 15 taking VPA, and 15 age and sex matched normal comparators were enrolled. In contrast to the effects of VPA, a statistically significant difference in T-score of WASl similarities and WASI-matrix reasoning subtests was observed between PHT and normal comparator group indicating poorer performance in intellectualfunctioning especially in executive function of the brain in patients taking PHT Vigor is the only mood dimension that demonstrated significant difference between epileptic patients and normal comparators. VPA appears to be more appropriate than PHT when executive brain function is mostly concerned, however, further investigation is needed to gain better insight into the effects of AEDs on cognitive domain of the Thai epileptic patients.