The purpose of a peripheral nerve root block is diagnostic to determine if a specific peripheral nerve root is the potential source of neck or low back pain. Besides the diagnostic benefits, some patients experience pain and symptom relief.
The procedure involves injecting a local anesthetic and corticosteroid into the nerve root sheath, a protective membrane (pia mater) covering each nerve root. A corticosteroid is a powerful, slow-releasing, and long-lasting anti-inflammatory medication effective in reducing inflammation and, in that way, reducing pain.
About Peripheral Nerve Roots
The brain and the spinal cord make up the central nervous system (CNS). The CNS extends to the peripheral nervous system (PNS). The PNS is a system of nerves that branch beyond the brain, brain stem, and spinal cord. The purpose of the peripheral nervous system is to carry information to and from the central nervous system.
Causes of Peripheral Pain and Other Symptoms
There are many types of peripheral nerve disorders. Some of these disorders are caused by other diseases such as diabetes, a virus, or infection. Complex regional pain syndrome (CRPS) is a rare but chronic problem that may affect the arms or legs. Other disorders cause nerve compression such as a herniated disc or spinal stenosis. Some patients are born (congenital) with peripheral nerve problems.
Symptoms of a peripheral pain disorder may include pain, numbness, muscle weakness, and sensations such as burning or tingling. Often, symptoms gradually worsen.
Patient Procedure Preparation
Those who decide to undergo peripheral nerve root block are usually patients with moderate to severe pain. Typically, patients who decide to have this proecure will be given instructions about their medications prior to the procedure. Certain drugs must be stopped several days before the procedure.
Possible Risks and Complications
A peripheral nerve root block, like other medical procedures, carries with it certain inherent risks. Complications include risk of infection, low blood pressure, headache, injury to nerve tissue, and allergic reaction to medication. The physician can provide complete information as to the risks and benefits of peripheral nerve root block for a specific patient.
What to Expect: The Procedure and After
During a peripheral nerve root block, the patient is awake so that he or she can communicate with the medical team and provide important feedback as to the effects of the procedure. The patient is brought into the operating room and positioned with cushions so that the doctor has good access to either the neck area (cervical region) or the lower back (lumbar region).The procedure site is cleaned with a sterile soap. A local anesthetic is injected and given time to take effect.
A fluoroscope C-arm (named for its characteristic C-shape) is positioned over the patient. The fluoroscope provides a kind of real-time X-ray projected on monitors in the operating room to help the physician and surgical team see what is happening. Using fluoroscopic guidance, the doctor places the needle tip at the target area. He then injects a small amount of contrast (dye) to ensure correct spread and confirms this by fluoroscope. Next, a low volume anesthetic / steroid solution is injected into the specific location. Rarely is pain increased during the injection. Following the injection, the injection site is bandaged. The physician may talk to the patient during the procedure and ask about symptoms and pain.
Typically, a peripheral nerve root block involves injections at two or more spinal levels (in two or more locations). This may vary by patient. Procedures take about 15 to 20 minutes. When it is concluded, the patient is brought to the recovery area, where he or she is monitored by a nurse. When the patient is ready to be discharged, he or she is given written instructions for home care. The patient should not drive home.
Results
After peripheral nerve root blocks, patients experience one of three results:
- No pain relief
- Pain is relieved for a few hours, or days, and returns
- Pain is relieved, returns for a short time period, and then improves again
The physician’s office typically maintains contact with the patient at home for 24 to 48 hours after peripheral nerve root block. Patients are asked to note their pain levels and symptoms in the days following the injection, with particular attention paid to where the pain occurred in relation to the injection site(s).
Conclusion
Peripheral nerve root block is an important treatment option that has provided considerable pain relief to certain types of patients with moderate to severe back or neck pain. Not all patients are candidates for peripheral nerve root block.