NERVE BLOCKS:  Part II

Last month, in Nerve Blocks--Part I, we reviewed spinal injections.  This time we will discuss  some of the other common nerve blocks.  Remember, blocks are not the best treatment for all pain problems.  Even when they are appropriate, they are usually more effective as a part of a more comprehensive treatment strategy.  Such a strategy may involve medications, physical therapy, stress management and relaxation training, occupational therapy, acupuncture, or other interventions.

The nerves outside of the brain and spinal cord are called peripheral nerves.  These nerves can be irritated or injured by trauma, surgery, scar tissue, or illness.  Blocks of peripheral nerves can help provide relief, especially if the underlying source of irritation can be resolved.  These nerves exist throughout the body; here are three examples of common peripheral nerve blocks.

1.      The occipital nerves travel from the cervical spine in the neck to the back of the head and scalp.  These nerves can be irritated by arthritic changes in the cervical spine, by muscle spasm, or by neck injuries.  The result can be headaches which typically start in the back of the neck and spread towards the forehead.  Occipital nerve blocks with steroids can often help with the treatment of these kinds of headaches.

2.      Chest injuries or surgery can damage the intercostal nerves, and trigger chronic chest wall pain.  Treatment may be facilitated by blocking or even freezing these nerves.

3.      The ilioinguinal nerve wraps around the rim of the pelvis and innervates part of inguinal (groin) and pubic areas.  The nerve can be damaged by surgery or by subsequent scar tissue following hernia repairs and cesarean sections.  Here too, nerve blocks may enhance the treatment.

In addition to the nerves that transmit sensation and motor (movement) control.  There are sympathetic and parasympathetic nerves that regulate blood flow, sweating, and glandular function.  Chronic pain conditions often involve malfunctions of the sympathetic nerves.  Blocks of these sympathetic nerves can provide important diagnostic information, and can also lead to a reduction of nerve sensitivity which can facilitate pain control and treatment.  These nerves run in chains along the spine and then branch out in fine nets towards the body part that they will innervate.  These blocks are typically done along various parts of the spine.

1. The sympathetic nerves of the stellate ganglion lie just in front of the spine in the lower neck.  Blocking these nerves can help with pain conditions involving the face, arms and hands. 
2. Similarly, the lumbar sympathetic nerves in front of the spine of the lower back can be blocked to help with pain conditions of the legs and feet. 
3. Pelvic pain often involves the sympathetic nerves in front of the sacrum.  These nerves can be blocked with injections just above or below the sacrum.
4. The celiac plexus (the solar plexus) is a bundle of sympathetic and sensory nerves which transmits much of the sensation from the abdominal organs.  Celiac plexus blocks can be very helpful for controlling pain from cancer that involves the abdomen.

Trigger point injections are not truly nerve blocks; rather they are muscle blocks.  Muscles that are chronically tense or in spasm become tender and painful.  The pain triggers more spasm and a vicious cycle develops.  Physical therapy and exercise are the primary treatments, but injections into the muscle can help to break the vicious cycle. 

I’ll save our discussion of implanted spinal pumps and stimulators for a later Update.

If your group would like a slide show talk, A Guided Tour of Nerve Blocks, please email me at the address below, or telephone 310-829-8080.

Until next time…Steven Richeimer, M.D.

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