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 blocks are used to treat chronic pain when drugs or other treatments do not control pain or cause bad side effects. A test block is usually performed with local anesthetic. If you achieve good pain relief from the local anesthetic, your doctor may inject a nerve block, such as alcohol or phenol.