I have not had experience with a cortisone shot in the back. I have taken oral steroids (prednisone) and IV steroids (Solu-Medrol) and had no symptom improvement. Since I have learned that steroids raise a person's blood sugar and then insulin as a result, I have no plans to use steroids in the future.
Long-term or high-dose use of steroids (a.k.a. glucocorticosteroids) has been linked to the development of diabetes.
My hypothesis: excess insulin (hyperinsulinemia) plays a major role in MS, as developed in my initial post: http://www.thisisms.com/forum/general-discussion-f1/topic1878.html "Insulin – Could This Be the Key?"