How Nerve and Facet Joint Blocks Relieve Pain

pain-procedure2Info from the Chicago Pain Management Doctors at PPS

Nerve blocks and facet joint blocks are used to treat the pain associated with many chronic conditions. Nerve blocks are used to numb nerves. This anesthetic effect relieves pain by interrupting the pain signals sent by the nerves to the brain. When a neurolytic agent is used, the pain relief is long-term.

What is the purpose of a nerve block?

A nerve block effectively reduces or alleviates pain by interrupting how pain signals are sent to the brain. This involves injecting a neurolytic substance (phenol or absolute alcohol) onto or around a nerve. The purposes of nerve blocks include:

  • To predict how pain will be relieved by long-term treatments.
  • To identify the source of the pain.
  • To treat conditions that cause pain.
  • To offer short-term pain relief after procedures and surgeries.
  • As an anesthetic during certain procedures.

What is a test block?

A nerve block can be used for chronic pain when medications and other treatments are not effective or cause uncomfortable side effects. The pain management specialist may first perform a test block, which involves a local anesthetic. When the patient achieves adequate pain relief from the anesthetic, the doctor then will inject a neurolytic agent onto the nerve.

What are the benefits of nerve blocks?

Nerve blocks using local anesthetics effectively control acute pain, such as an injection at the dentist’s office. Injuries often make nerves more sensitive, and nerves will be provoked easily. A nerve block will offer dramatic pain relief, promoting desensitization of sensory pathways. The Chicago pain doctor may choose to inject a corticosteroid onto the affected nerve, which reduces neural inflammation and abnormal triggering of pain signals.

What is the difference between a facet joint injection and a nerve block?

The facet joints are tiny joints along the posterior region of the spine. They have apposing surfaces of cushioning tissue (cartilage) between the bones and a surrounding capsule. With cartilage degeneration and age, these joints become damaged, which produces significant pain. A facet joint injection involves injecting medication into the inflamed joint to reduce inflammation and pain.

When the pain management doctor in Chicago suspects the facet joint is the pain generator rather than a nerve, a facet joint injection is done. More than one facet joints are often injected during a procedure. With a selective nerve root block, one nerve is injected rather than a joint.

How will the doctor know the procedure has worked?

When a facet block is done, the Illinois pain Facet Joint Injection Use thisdoctor guides the needle into the facet joint capsule using fluoroscopy (real-time x-ray). This assures correct placement of the needle. The facet joint injection is used as both a diagnostic tool and a therapeutic treatment, much like a nerve block. If the patient achieves pain relief following this injection, the pain specialist knows the injection has been effective.

Are nerve blocks and facet joint injections effective?

In a randomized clinical trial used to determine the effectiveness of lumbar facet joint nerve blocks, 100% of patients reported significant relief, which lasted up to 3 months, and 82% reported effects lasting for 4-6 months. Patients also noted improvement in overall health status and return-to-work status.


Manchikanti, L., Pampati, V., Bakhit, C.E. et al. (2001). Effectiveness of lumbar facet joint nerve blocks in chronic low back pain: a randomized clinical trial. Pain Physician, 4(1), 101-117.

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