My initial diagnosis of atypical Parkinsonism, multiple system atrophy, gave me on average a 5 year life expectancy. SPS, if treated appropriately can have a life expectancy of 20 or more years. Falls and respiratory complications can lead to life threatening issues, so use a cane if you need to, learn how to fall without injury from a physical therapist, and know when to adjust your medications. Make sure to manage your concomitant autoimmune disorder. IVIG or subcutaneous immunoglobulin treatments have helped in my case.