Treatment of acute relapses in multiple sclerosis.

Multiple sclerosis (MS) is a chronic progressive inflammatory demyelinating disease affecting the central nervous system. The most common clinical type of MS tends to follow a relapsing course, affecting the vast majority of patients living with this disease. Relapses are a hallmark of MS, and are often associated with significant functional impairment and decreased quality of life. Although usually followed by a period of remission, residual symptoms after MS relapses may persist and lead to sustained disability. Adequate management of MS relapses is important, as it may help to shorten and lessen the disability associated with their course. Historically, treatment of MS relapse was the first approach (and for a period of time, the only approach) to MS treatment in general. Systemic corticosteroids and adrenocorticotropic hormone (ACTH) have broad regulatory approval and remain the most established and validated treatment options for MS relapse. Therapeutic mechanisms of ACTH were previously associated (perhaps mistakenly) with only corticotropic actions; however, recently the direct anti-inflammatory effects and immunomodulatory activity of ACTH gel acting through melanocortin pathways have been shown. Second-line treatments of steroid-unresponsive MS relapses and a possible algorithm for MS relapse management are also reviewed in this article.