How To Treat Muscle Degenerative Disease That Has Attacked Arms And Stomach?

hi, i have a sister who is suffering with a muscle degenerative disease that has attacked her right and left arm. Over the years it has progressed slowly but seems to have spread into her stomach causing a lot of pain. She has consulted several doctors who have been unable to pin point the cause. I am looking for a top neurologist that she may go to.She is 39 years old had it since age 21 living in South Africa, Johannesburg.