Introduction: Neuromuscular autoimmune diseases, above all multiple sclerosis, have an increasing prevalence today. They develop with nonspecific symptoms, progress, have consequences on the functioning of the whole organism and are a major cause of disability. Case Report:A70-year old woman with difficulty in walking, cramps and numbness of the limbs seek medical help. The MRI of the brain and the cervical segment shows demyelination changes, typical of the multiple sclerosis, but due to the nonspecific clinical picture and age, the tests are directed to infectious agents, vasculitis. Later, because of swelling of extremities diagnosed the autoimmune polymyositis, but for the treatment is poorly reacted. Conclusion: Due to contradictory findings and a limited number of diagnostic procedures, multiple sclerosis are difficult to diagnose, remains undetectable, progresses and is often fatal, especially in the elderly.