Perspective/short review: Adverse events associated with placement of spinal cord stimulators (SCS)

Background: The placement of Spinal Cord Stimulator (SCS) trial or permanent electrodes carries a 31.9-43% morbidity/adverse event (AE) rate. Most AEs are attributed to electrode migration (EM: device-related AE 26.7% older cohort vs. 9.7% newer cohort), spinal epidural hematomas (SEHs: 0.81-2.6%), infection (3.4% older vs. 1.9% recent cohort), SCI (spinal cord injury: percutaneous 0.45% vs. 0.36% paddle electrodes), dural tears (DT/ cerebrospinal fluid leaks (CSF leaks)), foreign body/fibrous reactions, or syrinx formation. Methods: SCSs are typically applied to address chronic neuropathic pain syndromes. Here, we evaluated 20 articles focusing on patients who developed postoperative myelopathy/radiculopathy, variously attributed to MR-documented AE warranting medical or surgical intervention. Results: Postoperative symptoms/signs of AE typically included the acute development of new/increased weakness, sensory loss, and/or sphincter dysfunction. Requisite STAT MR scans usually confirmed the etiology of AE including electrode migration, SEH, DT, SCI, and/or postoperative scarring/fibrosis. Most patients warranted STAT surgery, while a small subset could be managed conservatively. Conclusion: The AE rate for spinal cord stimulators ranges from 31.9 to 43%. While the majority are due to electrode migration, other etiologies include SEH, SCI, DT, and foreign body reactions. Those who become acutely myelopathic usually warrant STAT MR scans with the majority additionally necessitating STAT surgical intervention to limit short/long-term neurological morbidity.