Lumbar radiculopathy (often known as Sciatica) refers to symptoms of pain, tingling, numbness or weakness that travel down the low back and into the leg or extremity. The sciatic nerve is the largest nerve in the body and exits the spinal cord as several nerve roots which join to form the sciatic nerve. The nerve, and the accompanying pain, radiate from the low back to travel behind the thigh and often below the knee to the ankle or foot.
Sciatica is not in itself a disease. However, the result is a process like disc degeneration, herniation that directly presses on the nerve, or the content of the disc, is an irritant to the nerve. Any irritation or inflammation of a nerve resulting from disc herniation is called a radiculopathy. In addition to disc herniation, the sciatic nerve may become irritated by adjacent structures, which include bone, muscle, tumors, infections, injury and bleeding. However, the most common cause of sciatica is a disc herniation.
The discs of the spine are composed of an inner gelatin-like core and a firm outer ring. As the disc wears, it weakens, and the inner core will protrude outward through the outer ring. The resulting pressure on the nerve roots exiting the spinal column are intensified by inflammation caused by damaged tissue.
Sciatica may occur as a result of degenerative disc disease, arthritis of the lumbar spine, and through trauma or injury to the lumbar spine. It is often diagnosed by history and symptoms, which include pain, burning, tingling or numbness that radiate from the lower back and buttock around the back of the thigh to cause low back pain, buttock pain, hip pain, or, most commonly, hip pain.
Diagnosis and Treatment
Most people with radiculopathy will seek medical attention from a primary care physician first for the pain. The doctor will begin with a thorough history of the patient and physical exam. Once the doctor identifies the exact location of the symptoms, he or she can determine which nerves are responsible for the condition. Tests ordered may include:
- X-ray: an X-ray can show the presence and cause of trauma, including herniated discs, osteoarthritis, and other causes.
- Magnetic resonance imaging (MRI): An MRI uses magnetic fields and radio-frequency waves to create an image of the spine, and can reveal fine details of the spine, including tumors, nerves, and any damage to the spine. An MRI scan can show details in the spine that can’t normally be seen on an x-ray. Sometimes a contrast agent is injected into a vein in the hand or arm during the test, which highlights certain tissues and structures to make details even clearer. In cases of radiculopathy, the affected nerves will be revealed.
- Computerized tomography (CT) is a noninvasive procedure that uses x-rays to produce a three-dimensional image of the spine. A CT shows more detail than an X-ray, and is sometimes used in addition to an MRI to reveal compression to the nerves.
After the diagnosis of sciatica is made, your physician may order other diagnostic tests to determine the cause of your sciatic nerve pain.
Many cases of radiculopathy can be treated successfully with conservative measures. These include the use of over-the-counter pain relievers and anti-inflammatories such as acetaminophen, and ibuprofen, as well as steroid injections, administered in a doctor’s office. Oral cortisone when the pain is mild, or epidural injections of corticosteroids when present with severe pain, can be helpful. The epidural works to relieve inflammation and swelling of the herniated disc, thus reducing irritation of the nerve.
Through a program of exercise, anti-inflammatory and muscle relaxant medications, and time, most patients have resolution of their pain. The body can resorb the disc.
Many patients are made more uncomfortable by sitting, and achieve some relief of pain by lying down or walking/standing. Bed rest has been traditionally the recommended therapy for sciatica. However, a study reported in the New England Journal of Medicine revealed that there was no difference in effectiveness between patients with sciatica treated with bed rest or with “watchful waiting.”
In 95% of cases, these simple treatments are effective. But for the remaining 5%, the excruciating pain caused by compressed nerves and nerve damage requires more aggressive treatments.
If the symptoms of the compressed nerves have not improved with conservative measures, then surgery may be the most effective option. With surgery, the herniated disc or damaged portion of the spine is operated on to relieve the pressure on the affected nerves. (See Surgery for Radiculopathy.)