Methylphenidate, cognition, and epilepsy: A 1-month open-label trial.

Abstract

Cognitive difficulties are common in epilepsy. Beyond reducing seizures and adjusting antiepileptic medications, no well-validated treatment exists in adults. Methylphenidate is used effectively in children with epilepsy and attention-deficit/hyperactivity disorder, but its effects in adults have not been systematically evaluated. We hypothesized that methylphenidate can safely improve cognition in adults with epilepsy. We detail here the open-label follow-up to a double-blind, placebo-controlled, single-dose study. Thirty epilepsy patients entered a 1-month open-label methylphenidate trial after a double-blind phase. Doses were titrated according to clinical practice and patient tolerance, ranging 20-40mg/day. Primary measures included: Conners' Continuous Performance Test (CPT), Symbol-Digit Modalities Test (SDMT), and Medical College of Georgia Memory Test (MCG). Secondary measures were: Beck Depression Inventory, 2nd Edition (BDI-II), Beck Anxiety Inventory, Apathy Evaluation Scale (AES), Stimulant Side-Effect Checklist, Adverse Events Profile, Quality of Life in Epilepsy-89 (QOLIE-89), and seizure frequency. Fourteen healthy, nonmedicated controls were tested concurrently. Twenty-eight participants with epilepsy (13 men/15 women) completed the trial. Withdrawals occurred due to anxiety (n=1) and fatigue (n=1). Mean age was 36.4 years (range=20-60). Epilepsy types were: focal (n=21), generalized (n=6), or unclassified (n=1). Mean epilepsy durationwas12.3years. Mean baseline seizure frequencywas2.8/month. There were significant improvements on methylphenidate for SDMT, MCG, CPT (the ability to discriminate between targets and nontargets [d'] hits, hit reaction time standard deviation, omissions, and commissions), and QOLIE subscales (energy/fatigue, attention/concentration, memory, and language; paired t tests; p≤0.002). BDI-II and additional subscales also improved, at a lower level of statistical significance. Effect sizes were moderate to large. Comparisons with untreated controls (n=14) revealed greater improvement for epilepsy patients on omissions and commissions, with improvement trends on d' and hits. Seizure frequency did not increase with methylphenidate treatment (2.8/month vs. 2.4/month). Methylphenidate may be an effective and safe option for improving cognition and quality of life in epilepsy. Larger and longer double-blind, placebo-controlled clinical trials are needed.