Nerve blocks and chronic pain states--an update. 2. Clinical indications.

With the unfortunate exception of the differential spinal block, diagnostic nerve blocking has become somewhat obsolete with the development of newer, more sophisticated diagnostic technology. Therapeutic nerve blocks remain useful in treating patients with various terminal cancers, some forms of back pain, tic douloreux, causalgia, reflex sympathetic dystrophy, and many trigger point syndromes. For dysfunctional and pain-disabled patients (rated as class 1 or 3 on Emory Pain Estimate Model), block therapy must be structured in comprehensive pain rehabilitation programs.