Spinal Cord Stimulation for Radicular Pain Following Retained Bullet in the Spinal Canal

Abstract

We are reporting on the implantation of a spinal cord stimulator to treat intractable radicular pain following a retained bullet fragment in the spinal canal. Such retained fragments are associated with risks including pain, neurological deficit, infection, toxic effects, and migration. Our patient was a young man with radicular pain and history of a gunshot entering the abdomen. Computed tomography of the spine had revealed a nearly complete bullet in the right paracentral canal at L4, partially extending into the lateral recess. He presented 17 months after his injury with gradually worsening pain and parasthesias radiating from the back to the whole right leg and foot. There was no weakness. As the patient had failed conservative therapy, procedural options were considered. In this case, the potential benefits of epidural steroid injection by any approach might not have outweighed risks of infection, related to foreign body and local steroid, or possible migration due to mechanical forces during injection. As he may well need repeated epidural steroid injections to manage his pain, this increases his risk for infection. A percutaneous trial spinal cord stimulation lead was placed, with epidural entry well away from the bullet. After good results, a permanent system was implanted. There was no evidence of infection or migration, and excellent pain relief was achieved. Bullets and other foreign bodies retained in the spinal canal can cause progressive neurologic symptoms through reactive tissue formation and compression. Spinal cord stimulation can relieve radicular pain while avoiding risks associated with altering the location of the offending foreign body. Key words: Spinal cord stimulation, radicular pain, retained bullet, gunshot wound, spinal canal, spinal injury, lumbar spine