Search

Introduction: Prior to the permanent implant of a spinal cord stimulator, patients typically undergo a screening trial using a percutaneously placed lead to ensure adequate response. However, due to several factors, patients may not be candidates for this screening trial and therefore instead undergo a "permanent trial" where either a percutaneous lead or paddle lead is placed using a tunneled extension for the trial, with the intent of conversion to a permanent system. If these patients proceed with an implant, the epidural space is not re-accessed and only an impulse generator (IPG) is needed. Although this technique is commonly employed, there is a paucity of literature describing outcomes with the "permanent trial" methodology. We present here our clinical experience with this technique., Methods: Participants who underwent permanent trials at a single institution between 2014 and 2020 were identified. Charts were reviewed to collect demographic information, numerical rating score (NRS) data, length of follow-up, revisions, complications, and removals., Results: A total of 27 patients who underwent permanent trial placement were identified from a database of 762 patients who underwent SCS placement (3.54%). The permanent placement group included 7 paddle trials, 14 percutaneous trials, and 6 dorsal root ganglion (DRG) trials. The reasons for pursuing a permanent trial included previously aborted percutaneous trial (n = 8), inability to hold anticoagulation for a prolonged period (n = 4), previous thoracic spine surgery or presence of thoracic stenosis on MRI (n = 4), and significant medical comorbidities precluding typical percutaneous trial lead placement at a surgery center (n = 3). 24/27 (88.8%) proceeded to permanent implant, and 16/24 (66.7%) were considered responders (greater than 50% reduction in pain) after 3 months. Over an average follow-up of 28.7 months, complications included 1 peri-operative intracranial hemorrhage delaying IPG placement, 2 lead fractures, 1 lead migration, and 1 CSF leak. Three patients required revision surgery for lead migration, lead fracture, and CSF leak, respectively. One patient had his system explanted 25.9 months after initial placement due to increased pain from stimulation., Conclusion: This study aims to characterize our experience with permanent trials for SCS. Here we demonstrate a higher rate of trial-to-implant conversion than previously documented for traditional percutaneous trials. We show similar rates of revisions and complications, elucidating the important role of permanent SCS trials in high-risk patients., (© 2025 World Institute of Pain.)

Objective: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known to reduce motor symptoms of Parkinson's disease (PD). The effects of DBS on various nonmotor symptoms often differ from patient to patient. The factors that determine whether or not a patient will respond to treatment have not been elucidated. Here, the authors evaluated sex differences in pain relief after DBS for PD., Methods: The authors prospectively evaluated 20 patients preoperatively and postoperatively after bilateral STN DBS with the validated numeric rating scale (NRS), Revised Oswestry Disability Index for low-back pain (RODI), and King's Parkinson's Disease Pain Scale (KPDPS) and assessed the impact of sex as a biological variable., Results: The cohort consisted of 6 female and 14 male patients with a mean duration of 11.8 ± 2.0 months since DBS surgery. Females were significantly older (p = 0.02). Covariate analysis, however, showed no effect of age, stimulation settings, or other confounding variables. KPDPS total scores statistically significantly improved only among males (p < 0.001). Males improved more than females in musculoskeletal and chronic subsets of the KPDPS (p = 0.03 and p = 0.01, respectively). RODI scores significantly improved in males but not in females (p = 0.03 and p = 0.30, respectively). Regarding the NRS score, the improvements seen in both sexes in NRS were not significant., Conclusions: Although it is well recognized that pain complaints in PD are different between men and women, this study is unique in that it examines the sex-specific DBS effects on this symptom. Considering sex as a biological variable may have important implications for DBS pain outcome studies moving forward.