Epidural Steroid Injection Therapy, Complications and Experimental Approaches Simulating Accidental Intra-Arterial Injection

Epidural steroid injections (ESIs) as minimally invasive procedures have been widely used for the relief of neck, arm, back, and leg pain potentially due to spinal stenosis, spondylolysis, or disc herniation. In rare instances, ESI therapy may cause clinical complications, some of which can be catastrophic. The surgical procedure itself including needle penetration, the potential use of contrast media, the injected medications (i.e., conventional steroids), or a combination of these in association with the original cause of the targeted pain which may include local inflammation, may account for such adverse complications. Nevertheless, there is increasing evidence indicating that ischemia and/or hemorrhage (stroke) in the brain and/or spinal cord, following accidental intra arterial injection of the medication is a primary contributor to the severe neurologic events. Descriptions of experimental intra arterial injections simulating the noted catastrophic outcomes associated with ESI therapy are very limited in the literature. Identifying and describing the cause of severe ESI complications will likely rely on the establishment of new experimental models simulating intra vertebral artery or intra-radiculomedullary artery steroid injections.