Radiculopathy occurs when a nerve is irritated as it leaves the spinal canal. Commonly thought of as a pinched nerve, radiculopathy is generally from a herniated disc or a bone spur that is pressing against an inflamed nerve root. Most often these are a result of degenerative changes in the spine.
Radiculopathy is caused by pressure on the nerve root, which is where the nerve leaves the spinal cord on its way to other parts of your body. There are 31 pairs of nerve roots, which exit the spine through small openings on each side of the vertebra called neural foraminae. The two nerve roots in each pair go in opposite directions when traveling through the foraminae. Nerve roots allow signals to travel to and from your brain and the rest of your body.
The most common cause of radiculopathy is a herniated disk, which causes the vertebrae above and below the disc to move closer together and "pinch" the nerve root. The disc between each vertebra responds by acting as a shock absorber. Bending the neck forward compresses the discs between the vertebrae and tends to bulge the discs backward toward the spinal canal and nerve roots.
Problems may occur when the center part of the disc, the nucleus pulposus, squeezes out of the disc and puts pressure on nerves in the neck. This condition, called a herniated disc, can happen when a tear in the outer ring of the disc (the annulus) allows the nucleus to squeeze through. The annulus can tear or rupture anywhere around the disc. If it tears next to the spinal canal, the nucleus can squeeze out and put pressure on the spinal cord or spinal nerves. Pressure against the nerve root from a herniated disc can cause numbness and weakness along the nerve. When the nerve root is inflamed, the added pressure from the disc may also cause vague, deep pain in the area of your body that the nerve serves. It can also cause sharp, shooting pain to radiate along the pathway of the nerve.
A herniated disc may occur when too much force is exerted on an otherwise healthy intervertebral disc. Heavy forces on your spine may simply be too much for even a healthy disc to absorb.
Herniated discs are more common in middle-aged adults. This is because the natural process of aging causes the discs to become weakened from degeneration. Less force is needed to cause the degenerated disc to herniate. Not everyone with a herniated disc has degenerative problems. Likewise, not everyone with degeneration will suffer a herniated disc.
In older people, degenerative disc disease can cause bone spurs to form near the nerve roots. If these bone spurs get big enough, they may begin to rub on the nerve root and irritate it. This usually occurs inside the foraminae. An irritated nerve root that is squeezed by a bone spur can cause the same symptoms as a herniated disc -- pain, numbness, and weakness in the affected part of your body.
Other common causes of radiculopathy include osteoarthritis, which usually affects the cervical spine (your neck) and lumbar spine (your low back). Radiculopathy can also be caused by certain types of tumors, diabetes, and certain infections including Herpes zoster, which is the virus that causes chickenpox and shingles.
The symptoms of radiculopathy vary depending upon which nerve roots are affected.
Cervical radiculopathy causes symptoms that radiate away from your neck. This means that although the problem is in your neck, the symptoms will be felt wherever the nerve travels - in your shoulder, arm, or hand. By locating the symptoms, your doctor can usually tell which nerve in your neck is having problems. Symptoms generally include pain, numbness, and weakness. The reflexes in your upper arm can also be affected. Neck pain and headaches near the back of your head are common with cervical radiculopathy. The back of your head is called the occiput, which is why headaches in this area are called occipital headaches.
Thoracic radiculopathy causes symptoms that feel like bands of pain around the area of your chest. Symptoms of lumbar radiculopathy include pain in your buttocks, the back of your thigh, calf and foot, and leg weakness. Radiculopathy in the sacroiliac, which is the bottom most part of your spine, can also cause pain in your buttocks and the back of yo9ur leg as well as leg weakness and loss of sensation.
Finding the cause of your radiculopathy begins with a complete history and physical exam. After the history and physical exam, your doctor may have a good idea of the cause of your pain or other symptoms. To make sure of the exact cause of your pain, your doctor may order additional diagnostic tests. These tests are used to find the cause of your pain, not to make it better.
Standard X-rays, are usually a first step in looking into any spinal problem. These include an oblique (angled) view, along with X-rays taken as you bend forward (flexion) and backward (extension). Your doctor will also determine whether other tests, such as an MRI, are needed.
If your doctor thinks that more than one pair of nerve roots are involved, a myelogram may be ordered. If the exact location of the nerve roots cannot be determined, your doctor may also order an electromyogram. If these tests do not find the cause of your radiculopathy, your doctor may order a spinal tap to check for an infection in your brain and spinal cord, and a blood glucose test to check for diabetes.
Medications are commonly used to control pain, inflammation, muscle spasm, and sleep disturbance. Your doctor may also prescribe a brace to limit movement and provide support. Your doctor may also have you work with a physical therapist. A well-rounded rehabilitation program assists in calming pain and inflammation, improving your mobility and strength, and helping you do your daily activities with greater ease and ability.
If other treatments do not relieve your pain, you may be given an epidural steroid injection (ESI), also called a nerve block. An ESI places a small amount of cortisone into the bony spinal canal. Cortisone is a strong anti-inflammatory medicine that may control the inflammation surrounding the affected nerves and may ease the pain caused by irritated nerve roots. This injection is often used when other conservative measures do not work, or in an effort to postpone surgery. This treatment is not always successful but may provide short-term help.
Radiculopathy doesn't always improve with conservative care. Surgery may be recommended when the following conditions are present: