masoud etemadifar department of neurology, isfahan neurosciences research center, school of medicine, isfahan university of medical sciences, isfahan, iran. noushin mehrbod department of neurology, school of medicine, isfahan university of medical sciences, isfahan, iran. leila dehghani department of medical sciences, school of medicine, islamic azad university, najafabad branch, isfahan, iran. aryan golabbakhsh medical students' research center, school of medicine, isfahan university of medical sciences, isfahan, iran. mahboobeh fereidan-esfahani medical students' research center, school of medicine, isfahan university of medical sciences, isfahan, iran. mojtaba akbari department of epidemiology, school of medicine, shiraz university of medical sciences, shiraz, iran.