Abstract
Despite the fact that adrenocorticosteroid hormones have been used in the treatment of multiple sclerosis for over 50 years, the extent to which they affect clinical disease activity remains unclear. Their administration results in the modification of a host of immune functions, including the downregulation of inflammatory cytokines and adhesion molecules involved in the trafficking of lymphocytes and macrophages across the blood–brain barrier. This leads to a rapid suppression of inflammation in multiple sclerosis lesions and to the restoration of the integrity of the blood–brain barrier. Clinical studies of adrenocorticosteroids in the treatment of multiple sclerosis have demonstrated a more rapid resolution of relapse, but have not uniformly demonstrated an improvement in the extent of recovery. More recent studies suggest that adrenocorticosteroid hormones may bring about a dose-dependent decrease in MRI measures of disease activity lasting 6 months, delay the time to second relapse and delay the time to sustained progression in relapsing–remitting and secondary–progressive multiple sclerosis. Though it is clear that adrenocorticosteroid hormones may have greater effects than previously realized, their role in the treatment of multiple sclerosis remains controversial because significant methodological differences between studies have often led to conflicting results.