Surgery is often considered the court of last resort for pain: When all else fails, cut the nerve endings. Surgery can bring about instant, almost magical release from pain. But surgery may also destroy other sensations as well, or, inadvertently, become the source of new pain. Further, relief is not necessarily permanent. After 6 months or a year, pain may return.
For all those reasons, the decision for surgery must always involve a careful weighing of the patient's condition and the outlook for the future. If surgery can mean the difference between a pain-wracked existence ending in death, versus a pain-free time in which to compose one's life and see friends and family, then surgery is clearly a humane and compassionate choice.
There are a variety of operations to relieve pain. The most common is cordotomy: severing the nerve fibers on one or both sides of the spinal cord that travel the express routes to the brain. Cordotomy affects the sense of temperature as well as pain, since the fibers travel together in the express route.
Besides cordotomy, surgery within the brain or spinal cord to relieve pain includes severing connections at major junctions in pain pathways, such as at the places where pain fibers cross from one side of the cord to the other, or destroying parts of important relay stations in the brain like the thalamus, an egg-shaped cluster of nerve cells near the center of the brain.
In addition, surgeons sometimes can relieve pain by destroying nerve fibers or their parent cell bodies outside the brain or spinal cord. A case in point is the destruction of sympathetic nerves (a part of the autonomic nervous system) to relieve the severe pain that sometimes follows a penetrating wound from a sharp instrument or bullet.
When pain affects the upper extremities, or is widespread, the surgeon has fewer options and surgery may not be as effective. Still, skilled neurosurgeons have achieved excellent results with upper spinal cord or brain surgery to treat severe intractable pain. These procedures may employ chemicals or use heat or freezing treatments to destroy tissue, as well as the more traditional use of the scalpel.
Recently, Harvard Medical School surgeons reported success with a new brain operation called cingulotomy to relieve intractable pain in patients with severe psychiatric problems. The nerve fibers destroyed are part of a pathway important in emotions and motivation. The surgery appears to eliminate the discomfort and suffering the patient feels, but does not interfere with other mental faculties such as thinking and memory.
Prior to operating, physicians can often test the effectiveness of surgery by using anesthetic drugs to block nerves temporarily. In some chronic pain conditions -- like the pain from a penetrating wound -- these temporary blocks can in themselves be beneficial, promoting repair of nerve damage.
How do these current treatments apply to the more common chronic pain conditions? What follows is a brief survey of major pain disorders and the treatments most in use today.