Sciatica
Sciatica is the name given to pain caused by irritation of the sciatic nerve. Anything that irritates this nerve can cause pain, ranging from mild to severe. Sciatica is usually caused by a compressed nerve in the lower spine.
Causes
Sciatica occurs when the sciatic nerve becomes pinched, usually by a herniated disk in your spine or by an overgrowth of bone (bone spur) on your vertebrae. More rarely, the nerve can be compressed by a tumor or damaged by a disease such as diabetes.
Risk factors
Risk factors for sciatica include:
- Age. Age-related changes in the spine, such as herniated disks and bone spurs, are the most common causes of sciatica.
- Obesity. By increasing the stress on your spine, excess body weight can contribute to the spinal changes that trigger sciatica.
- Occupation. A job that requires you to twist your back, carry heavy loads or drive a motor vehicle for long periods might play a role in sciatica, but there’s no conclusive evidence of this link.
- Prolonged sitting. People who sit for prolonged periods or have a sedentary lifestyle are more likely to develop sciatica than active people are.
- Diabetes. This condition, which affects the way your body uses blood sugar, increases your risk of nerve damage.
Symptoms of sciatica
The main symptom is a shooting pain anywhere along the sciatic nerve, from the lower back, through the buttock, and down the back of either leg.
Other common symptoms of sciatica include:
- numbness in the leg along the nerve
- tingling sensation (pins and needles) in the feet and toes
This pain can range in severity and may be aggravated by sitting for long periods.
Diagnosis
During the physical exam, your doctor may check your muscle strength and reflexes. For example, you may be asked to walk on your toes or heels, rise from a squatting position and, while lying on your back, lift your legs one at a time. Pain that results from sciatica will usually worsen during these activities.
Imaging tests
Many people have herniated disks or bone spurs that will show up on X-rays and other imaging tests but have no symptoms. So, doctors don’t typically order these tests unless your pain is severe, or it doesn’t improve within a few weeks.
- X-ray. An X-ray of your spine may reveal an overgrowth of bone (bone spur) that may be pressing on a nerve.
- MRI. This procedure uses a powerful magnet and radio waves to produce cross-sectional images of your back. An MRI produces detailed images of bone and soft tissues such as herniated disks. During the test, you lie on a table that moves into the MRI machine.
- CT scan. When a CT is used to image the spine, you may have a contrast dye injected into your spinal canal before the X-rays are taken — a procedure called a CT myelogram. The dye then circulates around your spinal cord and spinal nerves, which appear white on the scan.
- Electromyography (EMG). This test measures the electrical impulses produced by the nerves and the responses of your muscles. This test can confirm nerve compression caused by herniated disks or narrowing of your spinal canal (spinal stenosis).
Treatment
If your pain doesn’t improve with self-care measures, your doctor might suggest some of the following treatments.
Medications
The types of drugs that might be prescribed for sciatica pain include:
- Anti-inflammatories
- Muscle relaxants
- Narcotics
- Tricyclic antidepressants
- Anti-seizure medications
Physical therapy
Once your acute pain improves, your doctor or a physical therapist can design a rehabilitation program to help you prevent future injuries.
Steroid injections
In some cases, your doctor might recommend injection of a corticosteroid medication into the area around the involved nerve root. Corticosteroids help reduce pain by suppressing inflammation around the irritated nerve.
Surgery
This option is usually reserved for when the compressed nerve causes significant weakness, loss of bowel or bladder control, or when you have pain that progressively worsens or doesn’t improve with other therapies. Surgeons can remove the bone spur or the portion of the herniated disk that’s pressing on the pinched nerve.