[Recent therapeutic strategy for multiple sclerosis]

Multiple Sclerosis (MS) is an inflammatory demyelinating disease in the central nervous system (CNS), and it is clinically characterized by multiplicity in time (relapse and remission) and space (multiple lesions in CNS). In Asian countries including Japan, it has been pointed out that the prevalence rate of MS patients is extremely low and the frequency of the optic-spinal form of MS is high, compared with Western countries. Although the etiology remains unknown, it has been postulated that the pathogenesis of MS may involve immune mechanisms, virus-like infectious agents or genetic factors. MS should be attacked on two fronts: treatment to suppress the disease itself and alter its natural history, and treatment to improve the symptoms of MS and mask the deficits it causes. Although steroid therapy probably improves MS attacks by inhibiting the immune system and reducing inflammation, they seem ineffective in changing the natural history of the disease or preventing ultimate disability. Interferon beta has been approved as an effective drug for reducing the rate of MS attacks and the volume of MRI lesions and altering its natural history, based on positive results from large controlled trials in western countries as well as in Japan. Other immunomodulating treatments, such as glatiramer acetate, intravenous immunoglobulin, and mitoxantorone have been also approved as effective drugs for MS.