Injections

Nerve blocks are often used when simpler treatments such as medicines and therapy fail to produce lasting relief of CRPS symptoms. Only very qualified specialists should give them (almost always anesthesiologists with special training in pain management). Nerve blocks are done to stop the abnormal amount of pain that you may feel. A nerve block may be done by an injection (shot) of local anesthetics or other medicines into a group of nerves or a vein. Nerves may also be blocked with radiofrequency (heat) waves or with surgery. The long-term value of these procedures is unknown. There are considerable differences in availability depending on where you live and in types of procedures used.

You may need an injection (shot) of a nerve-blocking medicine because regular medicine does not decrease your pain enough. You may need a nerve block to control your pain enough to do physical therapy. You may receive an injection as part of the following nerve blocks:
 

Sympathetic Blockade

This nerve block may help patients with sympathetically maintained pain (SMP). During a nerve block, medicine is injected into a group of nerves, such as in the base of your neck or lower back. If a block works, it may provide weeks or months of relief from CRPS pain and discomfort. Once the nerve block stops working and your pain returns, you may have another block. Although nerve blocks can help relieve pain in the early stages of CRPS, they may stop helping after a while. If this happens, you may need to find other treatments to control your pain.

Nerve blocks may be done using radiofrequency (RF) probes. Depending on where you live, certain nerve blocks may not be available in your area. This fact has created difficulty in gathering enough research information about sympathetic blockades. It is one of the reasons why health care providers and insurance companies are confused about how to use sympathetic blockades for diagnosing and treating CRPS.
 

Somatosensory Blocks

Your health care provider will choose which type of nerve block to give you based on your signs and symptoms. You may have SMP, sympathetically independent pain (SIP), or both. If your signs and symptoms appear to be caused by SIP, you may get a somatosensory block. Like the sympathetic nerve block, this nerve block can be used for both diagnosing and treating CRPS. If this nerve block works, it may decrease or stop your pain and help your health care provider plan the right treatment for you.
 

Regional Anesthesia Blockade

This nerve block is given to relieve pain in an entire body part such as an arm or leg. During the procedure, you may wear an inflatable band such as a blood pressure cuff. It will be wrapped around the upper area of your CRPS-involved limb (near the armpit or upper leg). You will be given a local anesthetic through an IV to decrease or stop the pain in your arm or leg.

There are a number of other blockade techniques where doctors inject medicines into your spinal column. Spinal drug delivery techniques can be done with only one injection. They may also be done as a continuous infusion with an implantable pump that runs for several hours, days or months. These options require a specialist such as an anesthesiologist and may only be available in a limited number of medical centers.
 

Neurolytic (Neuroablative) Blocks

Unlike the other blocks discussed, a neurolytic block is a more permanent block. Medicine given during this block actually kills the nerves in which it is given. Neurolytic blocks may be done to different parts of the nervous system such as the somatosensory or sympathetic nervous system. Blocking sympathetic nerves by doing surgery (also called a sympathectomy) was once very popular but is not now. However, it still continues to be a method of treatment in many parts of the world for several reasons. This may be because of the sense of desperation that people with CRPS may bring to their physicians. It may also be due to the lack of knowledge about poor long-term outcomes with these procedures.

Many people who have had these procedures get temporary relief of pain, only to have the pain return months later. The pain that returns may be as bad or worse than the original pain. For this reason, it often does not make sense to have a neurolytic block to treat CRPS.