Frequency and clinical patterns of multiple sclerosis in Arab countries: a systematic review.

The susceptibility of various populations to multiple sclerosis (MS) and the clinical patterns of the disease are thought to be different. Nineteen articles related to incidence, prevalence and clinical patterns of MS in Arab populations were identified by keyword searching of Medline and Embase, and review of references in all relevant papers. Data were only available for the Kuwaiti, Jordanian, Libyan, Saudi, Iraqi, Palestinian (including Arabs living in Israel), and Omani populations. The publications ranged from 1975 to 2007. In Israel the incidence of MS was 0.7 per 100,000 per year in Arabs born and living in Greater Jerusalem. In Kuwait, the incidence of MS was 2.08 per 100,000. Prevalence varied from 4 to 42 per 100,000 population. The clinical pattern of MS was generally similar to that in western countries. However, one study from Oman found a high rate of optic-spinal disease (affecting one third of patients) and a low rate of oligoclonal bands (OGBs) (only one third of patients); this pattern resembles that of MS described in Asian countries. In conclusion, the prevalence of MS among Arabs has a wide reported range. The clinical pattern is generally similar to "Western type" MS but apparent differences in optic-spinal disease and OGBs positivity need further evaluation. There is significant opportunity for further evaluation of MS in Arabs, especially in unstudied areas, including the populous countries of Egypt, Algeria, Syria, and Morocco. Studies of Arab-Americans and Arab immigrants in Europe could help in defining the effect of immigration on MS. Such studies are likely to enhance our knowledge of the environmental, genetic and clinical variation of MS in Arabs.