Efficacy of Pharmacological Treatment of Working Memory Impairment After Traumatic Brain Injury: Evaluation With fMRI

This study is designed to examine the effects of a wake-promoting agent (Modafinil) on working memory (WM) in persons with moderate to severe TBI utilizing a double blinded placebo controlled methodology. Our approach is to evaluate participants with BOLD fMRI and a limited neuropsychological battery to examine WM performance before and after pharmacological intervention. Hypotheses 1. Because increased cognitive effort (as a function of decreased efficiency after TBI) is presumed to underlie fMRI activation dispersion that is seen during central executive WM tasks, we anticipate an attenuation of cerebral activation in prefrontal cortex during pharmacological intervention with Modafinil when compared to placebo administration on the mPASAT and vigilance testing. 2. There will be a correlation between the decreased dispersion of the fMRI signal on scans and improvement in neuropsychological measures when individuals are on Modafinil that is not seen when they are taking placebo.