Delayed development of spinal stenosis at the spinal cord stimulator percutaneous lead entry point: case report and literature review.

Background: Spinal cord stimulation (SCS) is an efficacious treatment for various refractory chronic pain syndromes. Serious complications including spinal cord compression (SCC) are rare with 19 previous reports which are mainly attributed to fibrotic scar tissue formation at the distal end of the leads at the location of the contacts. We report a case of SCC following SCS implantation at the lead entry location secondary to a delayed progression of spinal canal stenosis.

Case presentation: A patient in her early 70s underwent SCS implantation with adequate therapeutic benefit for approximately 2 years before citing complaints of increasing lower back pain and lower extremity radicular pain. Lumbar spine X-rays excluded lead migration as a causative factor. An MRI of the lumbar spine obtained 30 months following SCS implantation demonstrated a marked interval progression of central canal stenosis secondary to facet and ligamentous hypertrophy manifesting in compression of the spinal cord at the lead entry location. An L1-L2 decompressive laminectomy with hardware removal resulted in the resolution of her symptoms. A literature search conducted with the PubMed database identified previously published cases of SCC following SCS implantation which highlighted the rarity of this complication.

Conclusion: Our case report urges physicians of SCS patients, noting a loss of therapeutic benefit with their device, to investigate new pathologies including SCC. Furthermore, our case highlights clinical symptoms and surgical treatments of SCC. Paddle leads are more commonly implicated in published cases of SCC than percutaneous leads. Lastly, MRI conditionality is critical to identifying cases of SCC.