This procedure is performed to further evaluate and treat ongoing arm pain or leg pain.
Patients usually have had a MRI scan or CT scans which determined the anatomic cause of their pain. The procedure is used to confirm the presumed source of the pain to pinpoint it and confirm it. This makes the diagnosis more accurate and increases the success rate of spine surgery if it is indicated.
Local anesthetic and steroids are injected together along the nerve root sheath that contains the nerve root. The nerve root is identified either via temporary pain reproduction as the needle tip hits the nerve or by radiographic dye injection along the nerve root sheath. The nerve root is "numbed up" on temporary basis for a few hours and it is critical during this time for the patient to document whether their arm or leg pain is greatly relieved. If there is excellent temporary relief of the pain during the 1st few hours after the injection it indicates that pinching of that particular nerve is cause of their arm or leg pain. It is not as important how they feel after the anesthetic wears off. The steroids that are injected can at times give a prolonged pain relief sometimes making need for surgery unnecessary. Therefore the injection has both diagnostic and therapeutic value.
Patients need to bring along a driver as they are not allowed to drive home. They can return to preinjection activities of daily living the next day. Risks of the procedure include infection, nerve injury, and aggravation of their original pain but these are quite rare.
In the upper lumbar spine and lower thoracic spine rarely complete paraplegia or paralysis can occur there is embolization of steroid particles into the main feed artery that supplies blood to the spinal cord. Similar situation in the cervical nerve root injection can result in permanent stroke or quadriplegia in very rare cases. These are very rare complications but they can be devastating.