Phenytoin as a Neuroprotective Agent Against Corticosteroid-induced Functional Imaging Changes

The purpose of this research is to determine if patients who receive phenytoin (also commonly known as Dilantin) before taking corticosteroids will show less memory impairment and hypomanic symptoms (feelings of agitation, overexcitement or hyperactivity) than those receiving placebo (an inactive substance). This research also seeks to determine if patients taking phenytoin before corticosteroids show more activity in the area of the brain involved with memory than those receiving placebo. This research is being done because increased levels of cortisol (the body's natural corticosteroid) in the body are frequently associated with forgetfulness, and interventions that may prevent or reverse this effect are of great importance.