Making sense of sciatica

by Rick Alan

Who would think that one nerve could cause such severe pain? Pressure on the sciatic nerve can force even the most hardy person to seek treatment.

Sciatica. Just pronouncing it can be painful (sigh-AT-ik-ah). Sciatica gets its name from the longest and largest nerve in the body, the sciatic nerve. It is comprised of five small nerves that join together in the pelvis, after they exit the lower spine. The sciatic nerve then branches into two trunks that travel down the entire length of each leg, dividing again into smaller nerves as they reach the knees and the lower legs. Sciatica is defined as pain anywhere along the course of the sciatic nerve.

Pain that radiates

Although it can come on gradually or virtually overnight, the main symptom of sciatica is pain or discomfort that usually centers in the lower back and radiates down one leg. The pain can vary greatly in intensity and location. In some cases it is minimal and feels like a slight ache, a pins and needles feeling, or a slight numbness. In other cases, the pain can be extreme, making virtually any physical movement excruciatingly painful. And as noted, it can be felt anywhere along the length of the sciatic nerve from the lower back, hips or buttocks, all the way down the length of the legs and into the feet and toes.

Though it can affect anyone at any age, sciatica tends to be more common in men over age 40. Depending on the cause and the success of the subsequent treatment, sciatica can last for days, weeks, months or even years.

Causes can vary

Sciatica can result from a number of causes. Most commonly, it is caused by some portion of the spine rubbing against or putting pressure on the sciatic nerve. Most often, this rubbing or pressure results when one of the discs (cushions) that sits between the vertebrae of the spine becomes inflamed, ruptures or herniates (protrudes). What might cause these disc problems?

Injury to the disc itself, or to the ligaments around it
Arthritis in the lower back area
Constant pressure on the spine and lower back due to pregnancy, excess weight, or certain repetitive physical activities
Having one leg shorter than the other

Although less common, sciatica can also result when a blood clot, abscess, or some type of growth or tumor puts pressure on the sciatic nerve. As odd as it may seem, some men may be more susceptible to sciatica because they carry their wallets in their back pockets, at the exact spot where the sciatic nerve travels through the buttocks. When sitting, the weight of the wallet puts pressure on and, over time, can aggravate the sciatic nerve.

Treatment is conservative at first

In as many as 50% of all cases, sciatic pain will greatly diminish or disappear within a month with minimal (or even no) treatment. Therefore, the initial treatment is generally conservative, including:

Avoidance of all strenuous physical activity
Application of ice packs for 10-15 minutes, sometimes alternating with heat every twenty minutes, two or three times a day (NOTE: never apply ice directly to the skin.)
Adequate amounts of sleep
Anti-inflammatory drugs and pain relievers, such as aspirin, naprosyn or ibuprofen
Cox-2 inhibitors, such as Celebra and Vioxx, which are aspirin-like and can be used in high doses without gastrointestinal side effects
Corticosteriods may be injected into the spinal column for temporary reduction of inflammation

Kathy Shillue, a physical therapist at Boston's Beth Israel Deaconess Medical Center, stresses that, "Initially, you should get two to four days of bed rest, but no more than that, followed by as much activity as can be tolerated within the limits of the pain." Shillue also stresses that during the bed rest, you should lie on a firm mattress, keeping your unaffected leg slightly bent, with your affected leg straight and elevated by a pillow.

Looking for the source of pain

In cases where the pain remains severe or causes numbness, strange sensations or difficulty in walking for six weeks or more, your doctor or physical therapist may order tests to locate the cause of the sciatica. Such testing usually starts with an x-ray of the spine called a myelogram.This involves an injection into the spine. Imaging techniques such as CT scans and magnetic resonance imaging (MRI) have been used a great deal, but are now used less due to high cost and inaccuracy in their results. If the information obtained from a myelogram is inconclusive, an imaging scan will be performed.

Treatment will depend on what the tests find and on the duration and intensity of the pain.

Growth, tumor or blood clot

Surgery to remove it or drugs to clear or shrink it are usually prescribed.

Shorter leg

Orthopedic inserts or other adjustments to your footwear will often solve the problem.

Disc problem

Surgery, physical therapy, chiropractic or osteopathic treatment, or injections to reduce the inflammation are all options.

Dealing with disc problems

Because of the risks associated with surgery, particularly around the spine, many people will first opt for physical therapy, chiropractic and/or osteopathic treatment to try to ease or remove the pressure the disc places on the sciatic nerve.

If therapy doesn't work, you can have corticosteroid injections to reduce the inflammation. Though generally less risky than surgery, the injections do entail some risk, including the risk (though relatively low) of nerve damage. These procedures have produced mixed degrees of success in people with unrelenting sciatica, and recent studies have questioned the effectiveness of corticosteroid injections. Electro-thermal surgery is an experimental procedure that offers an alternative to receiving injections, using electricity to heat and shrink the swollen tissue. Some patients choose less conventional, although increasingly more accepted, procedures such as acupuncture or biofeedback.

Surgery may be necessary

If none of these treatments adequately control your sciatica, your doctor may suggest surgery. Surgery is usually a last resort though, and the desired results are not always obtained. The most common type of surgery for sciatica is a discectomy, whereby all or part of the disc that is pressing on the sciatic nerve is removed. Since the advent of laser surgery, some patients and their surgeons now opt for laser discectomy, a somewhat less invasive procedure whereby a laser is used to remove the portion of the disc that is pressing on the sciatic nerve. Removing part of the vertebra that presses on the sciatic nerve is a procedure called laminotomy.

Though both types of surgery are relatively safe and can reduce or eliminate the sciatic pain, both are considered major surgery of the spinal area and only have moderate success rates. Surgery to this area always carries some degree of risk, including the risk (though relatively small) of nerve damage.

Prevention: taking care of your back

As with most conditions, prevention is your best medicine. To avoid developing sciatica, take the following precautions:

Keep physically fit, exercise, and strengthen your abdominal and back muscles.
Try to retain good posture, both when sitting and standing, and avoid sitting for extended periods of time.
Avoid carrying your wallet in your back pocket, or keep its contents to a minimum.
Never bend over to lift something. When lifting an object, keep your back straight, bend your knees, and extend your arms to grab the object. Keep it close to your body and raise it by straightening your legs.

Finally, Shillue stresses that "While it may or may not be connected to a problem with your sciatic nerve, anytime you have a loss of muscle control in the leg (or loss of bowel or bladder control), it is imperative to seek medical attention immediately."

For more detailed information about tests and therapies, as well as experimental procedures see "Low Back Pain and Sciatica."