The term sciatica refers to a certain type of radiculopathy that occurs in the leg. It is called sciatica because it describes the radiculopathy that occurs when one or more of the nerves that make up the large sciatic nerve are irritated or pinched. Therefore, sciatica is not any different than a pinched nerve anywhere else in your spine. It simply has its own name because it is fairly common. It also occurs in the lumbar spine, the most common site of spinal nerve irritation.
Sciatica is used to describe the pain that travels from the sciatic nerve in the lumbar region of your spine into your buttocks, the back of your thighs, and sometimes into your calf and foot.
Sciatica is typically caused by irritation of the nerve roots that join outside your spine to make up your sciatic nerve. Your sciatic nerve braches off from your spinal cord and travels through your hips, buttocks, and down the back of your legs. The most common cause of sciatica is a herniated disc. The intervertebral discs in your spine act as shock absorbers to protect your spine and keep it flexible. If the disc deteriorates due to normal wear and tear or ruptures due to an injury to your spine, some of the contents of the disc may seep out and press against the sciatic nerve root. Other conditions that can cause sciatica are:
- Spinal stenosis – narrowing of your spinal canal, which can put pressure on the nerve
- Spondylolisthesis – displaced vertebra in your spine, which can pinch the nerve
- Piriformis syndrome – tightening or spasm of the piriformis muscle in your lower spine and upper leg, which can put pressure on the sciatic nerve
- Spinal tumors – tumor on or within your spine, which can compress the spinal cord and nerve root
- Trauma – an accident, fall or blow to your spine, which can injure the nerve root
You may be at particular risk for sciatica if you are over 40 years of age, because that is when the discs in your spine start to wear out. You may also develop sciatica if your job requires a lot of twisting or lifting, or if you have to drive a lot. People who sit for long periods of time are more likely to develop sciatica, as are people with diabetes because high blood sugar can increase the risk of nerve damage.
The main symptom of sciatica is pain that travels from your lumbar spine (your low back) to your buttock, and down the back of your leg. Some patients describe the pain as a mild ache, others as a sharp burning pain, and others as a severe jolt of pain. Coughing, sneezing, and sitting for long periods of time may make the pain worse. Sciatica can also cause numbness or muscle weakness along the path of your sciatic nerve into your leg or foot, and tingling or a pins-and-needles feeling in your toes or part of your foot. In extreme cases, sciatica can cause a loss of bladder or bowel control, which requires emergency treatment.
To diagnose sciatica, your doctor will start with a complete history and physical exam. Your doctor will also perform muscle tests to check your strength and reflexes. In most cases, mild sciatica gets better on its own. Your doctor may order additional diagnostic tests if your pain is very severe, if it lasts longer than 4 weeks, or if you have other serious medical conditions that could be complicating the problem in your spine, like cancer. These tests include X-rays to check the bones in your lower spine, an MRI to check for herniated discs, a CT scan, and a myelogram to look at your spinal cord and nerves.
Sciatica usually responds well to conservative treatments including hot and cold packs, stretching, exercise, and over-the-counter pain medications. Your doctor may also recommend physical therapy if a herniated disc is causing your sciatica. Your doctor may also prescribe stronger pain medications for you to help relax your muscles and reduce your pain. More aggressive treatments are usually only recommended when conservative treatment doesn’t relieve your symptoms.
Epidural steroid injection (ESI)
An epidural steroid injection (ESI) can be used to relieve the pain of a muscle strain or sprain, as well as to decrease inflammation. Injections can also help reduce swelling. Steroid injections are a combination of cortisone (a powerful anti-inflammatory steroid) and a local anesthetic that are given through your back into the epidural space. ESI is not always successful in relieving symptoms of inflammation. They are used only when conservative treatments have failed.
Surgery for sciatica is usually performed in cases where symptoms have not resolved after 6 weeks of conservative treatment. When a herniated disc is the cause of the pain, your doctor will perform surgery to remove part of the herniated disc that is pressing on your sciatic nerve. In this way, your doctor can decompress the sciatic nerve root and reduce the risk that your disc may herniate again.
If surgery on a herniated disc requires removal of a large section of bone and disc material, the section of spine may become loose or unstable. When this happens it may be necessary to fuse the bones right above and below the unstable section. Bone graft material is used to get the unstable bones to grow together. Rods, plates, and screws are commonly used to hold the bones in place so the bone graft heals.