Could Joint Pain In Shoulder, Ankles And Knees Be Related To Multiple Sclerosis?

i have joint pain in shoulders, ankles and severe pain in knees. i have excruciating pain in wrists and hands. i ve seen 3 Dr s and have had tests for arthritis and Lyme disease and other inflammatory problems. everything has come back negative. i m getting worse. last night i had the worst leg cramp ever and my legs fell weak today. could these be symptoms of MS?