Multiple sclerosis in Iran: a demographic study of 8,000 patients and changes over time

Iran was formerly considered to be located in a low prevalence zone for multiple sclerosis (MS). During the last decade the number of patients has increased. This study was conducted to estimate the prevalence of MS in the capital city of the country.

We re-evaluated the files of all patients who had registered at the Iranian Multiple Sclerosis Society during a 10-year period.

8,146 patients (72.3% female, 27.7% male) with a female-to-male ratio of 2.60 had registered. Mean age of disease onset was 27.24 (SD: 8.32). A relapsing-remitting pattern was recognized in 84.9% of the patients. The number of new registrations tripled from 2002 to 2008 and the female-to-male ratio increased from 2 to 3.12. The prevalence of MS in Tehran is estimated to be at least 51.9 per 100,000. Visual impairment was the main presenting symptom.

It seems that the prevalence of MS has increased to a medium-to-high risk level in Iran. The mean age of onset was similar to other studies but the calculated prevalence of early onset MS was increased. The cumulative data indicates that the female-to-male ratio is increasing annually.