A nerve block is a procedure intended to reduce or eliminate pain that originates from a specific nerve or nerves. It typically involves the injection of an anesthetic or anti-inflammatory medication near the targeted nerves to disrupt the pain signal. In some cases, the nerve block may be done by severing or burning the targeted nerve.
Sometimes referred to as a neural blockade, a nerve block is often used to manage nerve-related pain that doesn’t respond to medications or other treatments, or it may be performed as a diagnostic tool to help a physician pinpoint the origin of undiagnosed pain and determine the best treatment plan. A nerve block may also be used to minimize irritation to damaged nerves so they can heal more quickly.
Nerve blocks fall into two main categories: surgical and nonsurgical nerve blocks.
Surgical Nerve Blocks
During a surgical nerve block, targeted nerves are cut using a surgical tool, burned using chemicals or an electrical current or otherwise destroyed so they can’t send out impulses to the central nervous system (CNS), causing pain. Surgical nerve blocks are considered minimally invasive and are often used to treat debilitating chronic nerve pain conditions such as chronic regional pain syndrome. The effects of a surgical nerve block may last for several years and may even be permanent.
The following procedures fall under the category of surgical nerve blocks:
- Neurectomy: During this type of nerve block, damaged peripheral nerves are deliberately destroyed to reduce or prevent pain.
- Rhizotomy: During a rhizotomy, nerves that cause pain are burned or severed to disrupt the pain signal.
- Sympathetic blockade: In a sympathetic blockade, the patient receives a drug that disrupts the pain reaction of the sympathetic nervous system in a specific area of the body.
Nonsurgical Nerve Blocks
During a nonsurgical nerve block, medication is injected around a specific nerve or nerves, temporarily disrupting pain signaling to the CNS. The effects of a nonsurgical nerve block typically last for up to one to two weeks, and a series of treatments may be required to create long-term results.
The following procedures are considered nonsurgical nerve blocks:
- Peripheral nerve blockade: This common type of nerve block involves the injection of medication around a target nerve to disrupt the pain signal.
- Epidural analgesia/anesthesia: During an epidural, medication is injected outside the spinal cord. This technique is often used to manage pain associated with labor and delivery.
- Spinal analgesia/anesthesia: In this procedure, medication is typically injected directly into the fluid around the spinal cord.
Depending on the type of nerve block treatment, the procedure may be performed by a radiologist, a neurologist, an anesthesiologist or another pain management physician on an outpatient basis. Imaging guidance using CT, fluoroscopy or ultrasound is often used to accurately guide the needle to the targeted nerves.
How Does a Nerve Block Work?
During a nerve block procedure, the patient is positioned on a CT or fluoroscopic table in a way that gives the physician unencumbered access to the targeted injection site. Although certain surgical nerve blocks may involve general anesthesia, most nerve blocks are done using a local anesthetic.
To perform most common nerve blocks, the physician inserts a small needle through the skin. The medication, which may be an anti-inflammatory or an anesthetic, is administered with a syringe similar to those used for vaccinations. Treatments that involve larger body areas may require multiple injections.
To confirm the accuracy of the needle placement and ensure maximum benefit to the patient, a practitioner may use imaging guidance along with a small amount of contrast material. Low-level electrical stimulation may also be used to locate the nerves causing the pain.
The effects of a nerve block are often immediate and usually diminish in one to two weeks as the body absorbs the medication. Patients may require several rounds of treatment before experiencing extended relief. Because some surgical nerve blocks involve cutting or burning a nerve to destroy it completely, patients undergoing these procedures may experience long-term or permanent relief from pain.