Determining the source of spine pain is very difficult because of the number of structures in the spine that can contribute to the pain. Spinal injections can be used to diagnose the source of pain or they can be used as a treatment to relieve pain.
To diagnose the source of pain the medication is placed in or near the suspected area that is causing pain. If the patient reports their specific pain is relieved the injection can help the doctor understand the source of the pain.
Epidural Steroid Injections
Arm or leg pain often occurs when a nerve is irritated due to compression ("pinched nerve") near the spine. Epidural injections are used to treat pain that starts in the spine and radiates to an arm or leg.
A diagnostic injection involves injecting medicine at a very specific, isolated nerve to determine if that particular nerve is the source of pain. The response to the injection is closely monitored and if the pain is completely or nearly completely relieved, then that specific nerve is the primary cause of the pain symptoms. If there is little pain relief, then the cause of pain is from another area.