In a position statement, the North American Spine Society recommended the use of epidural steroid
injections in lumbar radicular pain caused by structural abnormalities such as disc herniation and spinal stenosis. If no improvement occurs, confirmation of the diagnosis is required. MRI is the test of choice, but it is important for the lesion, as seen on MRI, to corroborate with the location of symptoms. In borderline or ambiguous cases, electrodiagnostic testing can be helpful.