A numbing agent that is either applied to or injected into a small area of the body. It results in decreased pain sensation at the site of injection. Typical uses include numbing our mouth before dental work or numbing the site of a skin abscess before making the incision.
In the case of spinal pain, local anesthetics are often used as a diagnostic tool to help doctors determine the exact place in your spine from which the pain originates. Diagnostic injections are done to identify the place to treat. If a local anesthetic injected into a specific area that is suspect relieves your pain, your doctor knows where to treat you. To complete the diagnosis, the doctor will correlate that information with the findings from your MRI, CT scan or other diagnostic imaging test.
Lidocane is the most common local anesthetic used. Local anesthetics generally last no more than two hours. Should your doctor determine that a nerve block will likely help relieve your back or neck pain for a longer duration, the medication used for that treatment may contain a local anesthetic. In that case, the local anesthetic might be the only substance in the medication, or it may be mixed with other substances, including steroids.