Study designs of evaluations included in the review
Randomised controlled trials (RCTs) investigating the cognitive effects of AEDs using neuropsychological tests or behaviour assessments. Trials were excluded if they were AED-discontinuation studies.
Specific interventions included in the review
Anti-epileptic drugs in various dosages and combinations (carbamazepine (CBZ), phenytoin (PHT), phenobarbitone (PB), vigabatrin (VGB), valproate (VPA), zonisamide (ZNS), oxcarbazepine (OCBZ), ethosuximide (ESM), lamotrigine (LTG)). Comparator interventions included placebo, folic acid, piracetum, flunarizine, methylphenidate, oxiracetam, chlorazepate, sulthiame and tiagabine.
Participants included in the review
Included participants were child and adult patients who had seizures. Patients ages ranged from 4 to 88 years of age. Trials were excluded if they used only healthy volunteers. Patients after head injuries were excluded.
Outcomes assessed in the review
Changes in cognitive function using neuropsychological tests such as the Stroop Test, Finger Tapping Test, Digit Span, Weschler Adult Intelligence Test, Trail Making Test, Digit Symbol Modalities, LaFayette/Perdue Peg Board, Raven's Standard Progressive Matricies, Seashore Rhythm Test, Rey Complex Figure, Continuous Performance Reaction Task, Choice Reaction Time and Letter Cancellation Test. There were 70 other tests used less frequently in the included trials.
How were decisions on the relevance of primary studies made?
Two authors applied the inclusion and exclusion criteria when selecting the articles for the review.