Although research indicates that hightened glucocorticoid levels impair long-term memory functions and may inhibit traumatic memory retrieval in humans, the impact of acutely elevated glucocorticoid levels on learning and attentional functions is still unclear. Furthermore, the effect of glucocorticoids on executive functions as well as the recovery from long-term memory deficits is insufficiently studied. The present study examined memory functions in patients with acute exacerbation of neurological diseases (multiple sclerosis, acute optic neuritis), who were treated with a high dose of glucocorticoids. All patients demonstrated a reversible impairment of long-term memory functions, whereas measures of short-term memory, attentional functions, and alertness remained unaffected. These findings indicate a selective cognitive disturbance, providing further evidence that the memory deficits reflect a receptor-mediated effect of glucocorticoids on hippocampal function thereby supporting a potential association of stress-induced elevated cortisol levels and memory disturbances in trauma-related psychiatric disorders (psychogenic amnesia, PTSD).