Sciatica: What is it?
“Sciatica” is an old world term that refers to leg pain felt down the back of the thigh into the calf and foot. What about thigh pain? What about buttock pain? Unfortunately, “sciatica” has been wrongly applied to all types and locations of leg pain. In 1948, the use of the word “sciatica” was declared “unhelpful” by a leading orthopedic specialist because it is limited to a certain location and really does not address the origin of the pain. Over the years, many older medical terms like sciatica have become archaic as the newer research technologies give doctors clearer definitions and a better understanding of the human body. Leg pain that comes from the low back is most accurately categorized as referred pain or neurogenic pain. These terms apply to all locations and address the origin of the pain. With these newer terms, the antiquated word, “sciatica”, has no place in the modern world.
Sally has been waking up with right leg pain lately. This started when she strained her back while moving to her new apartment. Sometimes, she will feel a little tingling sensation in her little toe. Her mother told her not to worry because the pain is just sciatica. Sally doesn’t care what it is called because she just wants it to go away. The nights are utterly miserable when it feels like a hot poker is stabbing her leg.
Sally may not care what the leg pain is called. But, categorizing leg pain as either referred or neurogenic pain is a very important step towards finding a cure. If the leg pain is referred from the spine, then the pain would actually be coming from the spine structures like the ligaments, joints, or discs. Referred pain is a pain felt at a site distant to the origin of the pain. For example, in the event of a heart attack, sometimes the person will experience left arm pain. Nothing is wrong with the arm. But, the brain is just confused about where the pain is actually coming from; so, the arm hurts. The same thing can happen in the low back. A painful lumbar facet joint can refer pain into the groin, buttocks, or thigh. Referred lumbar pain should not be called sciatica because this type of pain can be in all areas of the leg. By calling the pain “referred pain”, healthcare practitioners will know the general cause of the pain which is very useful information for determining treatment (See Referred Pain: Can it be treated?).
On the other hand, if the leg pain is coming from the lumbar nerves, then it should be called neurogenic pain. When a damaged nerve becomes irritated enough to send pain signals down the nerve into the limb, this type of searing pain is considered “neurogenic”–from the nerve. Sometimes doctors will call it “radicular pain” if the nerve pain starts at the root of the nerve in the spine. The two most common situations that will lead to radicular pain are: disc herniations and spinal stenosis. Both of these problems can lead to a pinched, compressed, or angry nerve. In the case of lumbar radicular pain, the nerve pain does travel down the sciatic nerve which is why the pain is felt in the back of the thigh into the calf and foot. However, do not call this sciatica because the sciatic nerve is just the pathway for the pain, not the cause of this leg pain. Neurogenic pain is a more accurate, descriptive diagnosis for all types of nerve generated pain in multiple locations: head, arms, legs, feet, hands, etc. With this accurate diagnosis, treatment is more likely to be successful (See Neurogenic Pain: Can it be treated?).
Sally’s doctor does a thorough evaluation and determines that she does indeed have neurogenic pain in her leg that is probably caused by a herniated lumbar disc pressing on her lumber nerve root. She is told to use anti-inflammatory medications and avoid any bending, lifting or twisting for a while.
How can a doctor differentiate between referred pain and neurogenic pain if they can both involve the same limb? Sometimes just the quality of the pain can be the determining factor. Sally’s pain has the typical nerve pain symptoms of burning and tingling. Furthermore, referred pain is typically a dull, deep ache that is not as severe or sharp as “hot poker” nerve pain. When pain does not fit into this neat pattern, then a careful examination is required to check for the location of the damage. By determining the source of the pain, the accurate diagnosis is revealed and real solutions can be discussed.
Because referred pain and neurogenic pain respond to different treatments, neither should be lumped into the one category of “sciatic pain”. Sciatica is not an accurate diagnosis because it only leads to confusion about the location and origin of the pain. Referred pain and neurogenic pain are much more useful and modern terms which apply to all areas of the body and give information about the cause of the pain. This modernization of the medical language is important especially when dealing with antiquated words like “sciatica” that have been proven unhelpful.
Christina Lasich, M.D., wrote about chronic pain and osteoarthritis for HealthCentral. She is physiatrist in Grass Valley, California. She specializes in pain management and spine rehabilitation.