[Nerve block for the treatment of chronic pain].

Nerve block is useful for the treatment of acute pain and cancer pain; however the treatment's effectiveness with regard to non-cancer chronic pain is controversial. Of the non-cancer diseases, trigeminal neuralgia and spinal facet joint pain, in which long-term pain relief can be obtained by the nerve block without serious complications in most of patients, are well suited for the nerve block. Systemic reviews for the treatment of radicular pain from spine disorders with the nerve block showed contradictory long-term results. In other chronic pains, the effectiveness of nerve blocks has not been proved, although anecdotal reports suggests that a small proportion of patients respond well to the nerve block. Further study is necessary to examine what kinds of pains and patients will be relieved with the nerve block.