Principles & Practice of Pain Medicine > Part II. Pain: General Principles and Evaluation > Chapter 11. Diagnostic Injections for Spine Pain Conor W. O'Neill, Richard Derby, and Laura R. Kenderes

Spinal Pain

"There are two types of spinal pain: radicular pain and axial pain.⁶ Radicular pain results from mechanical compression or chemical irritation of a nerve root, or both. Establishing an anatomic diagnosis for patients with radicular pain is important, as surgical treatments have excellent outcomes in well-selected patients. The source of radicular pain, typically either a herniated nucleus pulposus or spinal stenosis, can be definitively diagnosed at surgery; therefore, there is a gold standard that can be used to assess the validity of diagnostic studies. Consequently, the ability of both clinical findings and imaging studies to diagnose the site of pathology is well defined. A diagnostic injection may be indicated when imaging studies suggest that more than one nerve root may be responsible for a patient's symptoms. In that circumstance, a selective epidural injection may be useful...."