What is a nerve root and why is a selective nerve root block helpful?

Nerve roots exit the spinal cord and form nerves that travel into the arms or legs. These nerves allow movement of the arms, chest wall, and legs. These nerve roots may become inflamed and painful due to irritation, for example, from a damaged disc or a bony spur.

A selective nerve root block provides important information to physicians but is not a primary treatment. It serves to prove which nerve is causing pain by placing temporary numbing medicine over the nerve root of concern. If a patients usual pain improves after the injection, that nerve is most likely causing the pain. If the pain remains unchanged, that nerve is generally not the reason a patient may be experiencing pain.

By confirming or denying the exact source of pain, it provides information allowing for proper treatment, which may include additional nerve blocks and/or surgery at a specific level.

What happens during the procedure?
An IV will be started so that relaxation medication can be given. The patients is placed on the X-ray table and positioned in such a way that the physician can best visualize the bony openings in the spine where the nerve roots exit the spine using x-ray guidance. The skin on the back is scrubbed using 2 types of sterile scrub (soap). Next, the physician numbs a small area of skin with numbing medicine. This medicine stings for several seconds. After the numbing medicine has been given time to be effective, the physician directs a very small needle, using x-ray guidance near the specific nerve being tested. A small amount of contract (dye) is injected to insure proper needle position. This may increase the patients usual pain for about 30 minutes. Then a small mixture of numbing medicine (anesthetic) and anti-inflammatory (cortisone/steroid) is injected.

What happens after the procedure?
Immediately after the procedure, the patient will move around and try to imitate something that would normally bring about their usual pain. Patients are then asked to report the percentage of pain relief and record the relief experienced during the next week on a post injection evaluation sheet ("pain diary"). This will be given to the patient when they are discharged home.

The arm(s), chest wall or leg(s) may feel weak or numb for a few hours following the procedure. This is fairly common and happens following a selective nerve root block.

General Pre/Post Instructions
Patients can eat a light meal within a few hours before the procedure. If a patient is an insulin dependent diabetic, they must not change their normal eating pattern prior to the procedure. Patients may take their routine medications. (i.e. high blood pressure and diabetic medications). Patients should not take pain medications or anti-inflammatory medications the day of their procedure. Patients have to be hurting prior to this procedure. They may not take medications that may give pain relief or lessen their usual pain. These medicines can be restarted after the procedure if they are needed.