Nerve Blocks: Part 2
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 comprehensive treatment strategy. Such a strategy may involve medications, physical therapy, occupational therapy, stress management, relaxation training, acupuncture, or other treatments.
Peripheral Nerve Blocks
Let's begin by taking a look at peripheral nerves, the nerves outside of the brain and spinal cord. These nerves transmit sensation and motor (movement) control. They can be damaged by trauma, surgery, scar tissue, or illness. Blocks of peripheral nerves can help provide relief. 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 damaged 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.
2. Chest injuries or surgery can injure the intercostal nerves, and trigger chronic chest wall pain. A valuable part of the treatment may be to block or even freeze these nerves.
3. The ilioinguinal nerve wraps around the rim of the pelvis and goes to the 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.
Sympathetic Nerve Blocks
Chronic pain conditions often involve malfunctions of the sympathetic nerves. These nerves regulate blood flow, sweating, and glandular function. Blocks of these sympathetic nerves can provide important diagnostic information, and can also lead to a reduction of the pain. Here are four examples of common sympathetic nerve blocks:
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 help control a variety of chronic abdominal pains, especially cancer related pains.
Many people are not aware that 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 then 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 cycle.
Recent Advances in Injection Technique
Until a few years ago, most blocks were placed "blindly," according to the doctor's "feel" of the patient's anatomy. Now, much more accurate needle placement is achieved by using fluorscopic (x-ray) guidance. In difficult cases, where the anatomy might be distorted by tumors, then CT guidance is used. The other new development is the use of curved needle techniques for deeper injections. By using curved needles and fluoroscopic guidance, the pain specialist can gently twist and turn the needle directly to the target. This avoids the use of multiple attempts to get the needle properly positioned. The result is better needle placement with less discomfort.
© 2000, Steven Richeimer, MD.
You may reach The Richeimer Pain Institute at www.helpforpain.com