Neck and Back

Sciatica

Anatomy

The spinal column is made up of small bones (vertebrae) stacked on top of one another, creating the natural curves of the back. Between the vertebrae are flat, round, rubbery pads (intervertebral disks) that act as shock absorbers and allow the back to flex or bend. Muscles and ligaments connecting the vertebrae allow motion while providing support and stability for the spine and upper body. Each vertebra has an opening (foramen) in the center and these line up to form the spinal canal. Protected by the vertebrae, the spinal cord and other nerve roots travel through the spinal canal. Nerves branch out from the spinal column through vertebral openings, carrying messages between the brain and muscles. Facet joints align at the back of the spinal column, linking the vertebrae together and allowing for rotation and movement. Like all joints, cartilage covers the surface where facet joints meet.

The spine contains three segments: lumbar, thoracic and cervical. The lumbar spine consists of five vertebrae located in the lower back; lumbar vertebrae are larger because they carry more of the body's weight. The thoracic spine consists of 12 vertebrae and begins at the upper chest, extending to the middle back and connecting to the rib cage. The cervical spine includes the neck and consists of seven small vertebrae, beginning at the base of the skull and ending at the upper chest. Disks in the lumbar spine are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine, disks are similar but smaller in size.

Description

Most common between 30 and 50 years of age, sciatica is a pain in your lower back or hip that radiates to the back of your thigh and into your leg. Often people think that the source of the pain is the buttock, hip or thigh and seek medical care for a “hip” problem only to learn that the source of the pain is the lower back. Sciatica is commonly caused by a herniated disk, which occurs when the nucleus of a disk protrudes into or through the disk's outer lining. Approximately 1 in 50 people will experience a herniated disk at some point in their life. Of these, 10% to 25% have symptoms that last more than 6 weeks. In rare cases, the herniated disk may press against nerves and cause the patient to lose bladder or bowel control, referred to as cauda equina syndrome. This may be accompanied by numbness or tingling in the groin or genital area. This is an emergency situation that requires surgery—seek medical attention immediately.

Symptoms

Sciatica may feel like a bad leg cramp, with pain that is sharp ("knife-like"), or electrical. The cramp can last for weeks before it goes away. You may have pain, especially when you move, sneeze or cough. You may also have weakness, numbness, or a burning, tingling or "pins and needles" (paresthesia) sensation down your leg.

Causes

Sciatica is most commonly caused by a herniated disk in the lumbar spine that presses directly on roots of the sciatic nerve. Inflammation and irritation may also occur when these nerve roots are exposed to chemicals from the herniated disk's nucleus. Sciatica can also be the result of the general wear and tear of aging, plus any sudden pressure on the disks that cushion the lumbar vertebrae.

Diagnosis

After reviewing your medical history, your physician will ask you to describe how your pain started, where it occurs, and exactly how it feels. A physical examination may help pinpoint the irritated nerve root, and you may be asked to squat and rise, walk on your heels and toes, or perform straight-leg raising or other tests. X-rays and additional imaging studies, such as a magnetic resonance images (MRI), may be required to fully assess and diagnose your condition, and to confirm which nerve roots are affected.

Nonsurgical Treatment

Given sufficient time and rest, this condition usually heals by itself. Approximately 80% to 90% of patients with sciatica get better over time (typically within several weeks), without surgery. Nonsurgical treatment is focused on helping you manage pain without long-term use of medications. Applying gentle heat or cold may help to soothe painful muscles, and nonsteroidal, anti-inflammatory drugs such as ibuprofen, aspirin, or muscle relaxants may be recommended. Your physician may also inject a cortisone-like drug into the spinal area to provide short-term relief. Motion helps to reduce inflammation, and it is important that you continue to move during the healing process. Be as active as possible. Find positions that are most comfortable, and as soon as you are able, begin stretching exercises to help you resume physical activities without pain. A spine conditioning program or low back exercises may also be recommended.

Surgery

If you are still experiencing disabling leg pain after 6 or more weeks of nonsurgical treatment, surgical removal of the herniated disk may be necessary to stop it from pressing on your nerve. Surgery (laminotomy with diskectomy) may be performed under local, spinal or general anesthesia and it is usually very successful at relieving pain, particularly if most of it is located in the leg.

Complications

As with any surgery, there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. For most people, surgery can provide relief of symptoms and return to function with relatively low risk of complications. Overall, elderly patients have higher rates of complications from surgery, as do patients who are overweight, diabetics, smokers, or suffering from multiple medical problems. Among the general, potential risks associated with surgery are infection, bleeding and blood clots, and reactions to anesthesia. Be sure to discuss the potential risks and benefits with your surgeon prior to surgery.

Rehabilitation

During rehabilitation, physical therapy may be prescribed. Your physician may recommend that you take short walks and perform special exercises to strengthen your back. Although movement is very important, any bending or twisting of the spine should be limited. Routine activities such as cooking and cleaning are typically acceptable. Discuss which activities you should begin, and when, with your surgeon or physical therapist. Following treatment for sciatica, most patients are able to resume a normal lifestyle and keep pain under control. However, if the disk has not been removed, it is possible for it to rupture again.