The central nervous system is composed of the brain and spinal cord. The spinal cord serves as headquarters for nerves that are routed to and from other parts of the body. The nerves that branch out to other body parts are referred to as peripheral nerves. The spinal cord and its peripheral nerve roots are housed within a stack of bones, known as the vertebral column. A cushion-like disc (with a gelatinous center) sits between the vertebrae.
Thirty-one pairs of nerves exit the spinal cord through openings between the vertebrae and then branch out to other parts of the body. The point of exit for a nerve is called a nerve root. Peripheral nerves consist of sensory nerves and motor nerves. Sensory nerves are associated with how something feels (e.g., hot, cold, painful). Motor nerves (which lead to muscles) are associated with movement.
To break this down even further, individual nerve cells consist of an axon (the inner pathway whereby information is transmitted) and a myelin sheath (a fatty outer covering that protects the nerve cell and helps transmit information). An injury or irritation to any part of nerve structure can cause nerve pain.
Categories of Nerve Pain
There are actually two categories of nerve pain -- nociceptive pain and neuropathic pain (i.e., neuropathy). With nociceptive pain, nerves transmit impulses to signal that a part of the body has been injured or damaged. With neuropathic pain, the nerve itself is what is injured causing an abnormal transmission of impulses.
Symptoms of Nerve Pain
Nerve pain can express itself in a few different ways, depending on the location and cause of the nerve injury or damage.
- There may be increased sensitivity at the skin level, in the area served by the damaged nerve. When this is the case, gentle touching in this area is felt as pain -- sometimes severe pain.
- There may be numbness along the path of the damaged nerve. Generally, when this is the case, the numbness always occurs in the same location (e.g., the foot associated with the damaged nerve). It may be constant or intermittent. It may occur with a stabbing sensation or a burning sensation. It may grow worse with movement.
- Muscles supplied by the damaged nerve may become weak, or in some cases, paralyzed.
Causes of Nerve Pain
Nerve pain may be linked to various medical conditions or exposure to certain chemicals, as well as traumatic injury. Possible causes include:
- Multiple sclerosis
- Complex regional pain syndrome
- Lead ingestion
- Vitamin deficiencies
- Herniated disc
- Inflammation of the nerve
- Compression of the nerve or pinched nerve
- Certain medications
There is some evidence that abnormalities in both the central and peripheral nervous systems play important roles in fibromyalgia, although the cause of fibromyalgia remains unknown. Drugs effective in treating fibromyalgia are also effective at treating nerve pain.
Diagnosing and Treating Nerve Pain
To diagnose nerve pain, typically, patients have a comprehensive neurological exam, an MRI to evaluate the structure of the nerves, and an EMG (electromyelography) to evaluate nerve conduction. If necessary, a spinal tap may provide more information.
There are several options for treating nerve pain. Depending on the location and type of nerve pain, and the cause if it is known, medications, injections, epidurals, alternative treatments, spinal cord stimulation, nerve ablation, and sometimes surgery may provide relief from nerve pain.
The Bottom Line
On a personal note, I just went through an experience with nerve pain in December 2012 and January 2013. MRI revealed a herniated disc along with facet arthropathy. I would say, it was the most severe, debilitating pain I ever experienced, above and beyond my usual rheumatoid arthritis pain. I would recommend that people with nerve pain learn what's causing their pain and learn about treatment options. Understand your options. I had a series of three nerve blocks and was able to obtain 85% relief. Be sure you have a well-respected neurologist and a pain management doctor on your team, too.
Anatomy of Nerve Pain. spine-health. Accessed 07/18/13.
Nerve Pain. University of Michigan Neurosciences. Accessed 07/18/13.