The presidential primary system has a rich and interesting history in American politics. From the nominations by caucus, in the days of the Founding Fathers, to the most recent contests, we have seen the electoral process go through a dramatic change.
Usually a nerve root block is only carried out when other methods of treatment have tried and failed and any nerve root that is blocked, will have been the most likely originator of pain. The procedure is not undertaken on each particular nerve.
Nerve injury after a regional block is a rare occurrence, which can occur anywhere from 1 in 4000 blocks to 1 in 200.000 blocks depending in the type of block and specific risk factors. It can be related to direct needle injury of the nerve or to secondary complications like bleeding or infection.