Cervical Nerve Root Blocks
What is a nerve root block?
A nerve root block is a surgically invasive procedure, administered for pain relief associated to the nerve roots.
A nerve root exits the spinal cord and forms nerves that travel into the arms or legs. These nerves allow movement of the arms, chest wall and legs and may become inflamed and painful due to irritation, from causes such as a damaged disc or a bony spur.
When is a cervical nerve root block required?
Cervical (of the neck) nerve root blocks (CNRBs) play a very important role in the conservative treatment of patients with cervical radicular pain.
A cervical nerve root block is generally advised for the patients in the following circumstances:
- Therapeutic effects are required to delay or prevent surgery
- Imaging studies are normal
- Imaging studies show multiple levels of pathology
Generally, a cervical nerve root block will be performed to determine if a specific nerve root is the source of pain. Another important aim is to reduce inflammation around the nerve root, thus decreasing or relieving the pain.
A research by Strobel et al strongly suggest that patients with disk herniation, foraminal nerve root compromise and no spinal canal stenosis appear to have the greatest pain relief after this procedure.
What is the procedure?
After all the aspects of the procedure have been explained to the patient, along with its risks and side effects, a consent form is signed seeking the patient’s formal approval. Once done, the procedure will generally follow the below steps:
- An IV will be started to ensure that a relaxation medicine can be started.
- The patient is then placed on the x-ray table and positioned in a way to facilitate the best-desired view, using the x-ray guidance.
- The skin is then scrubbed using two types of sterile scrub.
- Once done, the physician will numb a small area of the skin with a numbing medicine, which might sting for a few seconds.
- After the numbing medicine has had the desired effect, the physician directs a very small needle with x-ray guidance, near the specific nerve being tested.
- To ensure proper needle position, a small amount of contract (dye) is injected, somewhat increasing the usual pain for 30 minutes.
- Finally, a small mixture of numbing medicine (anesthetic) and anti-inflammatory (cortisone/steroid) is injected.
Once the procedure is over, the arms, chest wall or legs may feel weak or numb for a few hours. This a very common after-effect of a selective nerve root block, such as the CNRB.
What are the risks involved?
A series of risks might be involved in relevance to the cervical nerve root block procedure, including:
- Allergic reaction
- Nerve damage
- Transient weakness or paralysis
- Injury to carotid or vertebral arteries
- Spinal cord stroke (rare)
- Death (rare)
Should I follow any precautions?
A patient about to undergo a cervical nerve root block is advised to observe the following precautions:
- Eat a light meal before the procedure.
- Do not change your eating pattern if you are an insulin dependent diabetic.
- Do not take any pain medications or anti-inflammatory medications on the day of the procedure.