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

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

Mitochondrial disease: an uncommon but important cause of diabetes mellitus

Mitochondrial diseases are rare, heterogeneous conditions affecting organs dependent on high aerobic metabolism. Presenting symptoms and signs vary depending on the mutation and mutant protein load. Diabetes mellitus is the most common endocrinopathy, and recognition of these patients is important due to its impact on management and screening of family members. In particular, glycemic management differs in these patients: the use of metformin is avoided because of the risk of lactic acidosis. We describe a patient who presented with gradual weight loss and an acute presentation of hyperglycemia complicated by the superior mesenteric artery syndrome. His maternal history of diabetes and deafness and a personal history of hearing impairment led to the diagnosis of a mitochondrial disorder. Learning points: •• The constellation of diabetes, multi-organ involvement and maternal inheritance should prompt consideration of a mitochondrial disorder. •• Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS) and maternally inherited diabetes and deafness (MIDD) are the most common mitochondrial diabetes disorders caused by a mutation in m.3243A>G in 80% of cases. •• Metformin should be avoided due to the risk of lactic acidosis. •• There is more rapid progression to insulin therapy and higher prevalence of diabetic complications compared to type 2 diabetes. •• Diagnosis of a mitochondrial disorder leads to family screening, education and surveillance for future complications. •• Superior mesenteric artery syndrome, an uncommon but important cause of intestinal pseudo-obstruction in cases of significant weight loss, has been reported in MELAS patients.