multiple sclerosis: a disease on a dramatically rising trend in iran; review of possible reasons

background: there has been a global rising trend in recent years in the incidence of multiple sclerosis (ms). despite being an ms low-risk region, this disease has also been recently on the rise in the middle east. as part of the middle east, iran has not been spared either; however, the cause of this dramatic increase remains to be discovered. the present study reviews possible reasons for this increase in iran. key messages : although many factors such as the increased rate of smoking, lifestyle changes, modernization and contact with toxic solvents can be proposed as reasons for this sudden rise in the prevalence of ms in iran, these factors cannot be taken as definite causes and further studies are required to prove their impact.