Fantastic Four: Age, Spinal Cord Stimulator Waveform, Pain Localization and History of Spine Surgery Influence the Odds of Successful Spinal Cord Stimulator Trial

摘要

Background: There is a dearth in our understanding of the factors that are predictive of successfulspinal cord stimulator (SCS) trials and eventual conversion to permanent implants. Knowledge ofthese factors is important for appropriate patient selection and treatment optimization.Objectives: Although previous studies have explored factors predictive of trial success, few haveexamined the role of waveform in trial outcomes. This study sought to establish the relationship ofneuraxial waveform and related measures to trial outcomes.Study Design: This study used a retrospective chart review design.Methods: Data were retrospectively collected on 174 patients undergoing SCS trials uponinstitutional review board approval of the study protocol. Indications for SCS were: complex regionalpain syndrome, failed back surgery syndrome with radicular symptoms, peripheral neuropathy, andaxial low back pain. Descriptive statistics and logistic regression analyses were used to assess theassociation of demographic and clinical variables with SCS trial outcomes.Results: The study population comprised 56% women, had a median age of 55 (interquartilerange [IQR], 44-64), and 32 of 174 (18%) patients failed SCS trials. Individuals with successfultrials (≥ 50% pain relief) were significantly younger and had a median age of 54 years (IQR, 42-60)compared to those who failed SCS trials (median age 66 years; IQR, 50-76; P = .005). Adjustingfor age, gender, number of leads, pain category, and diagnoses: surgical history (odds ratio [OR] =4.4; 95% confidence interval [CI], 1.3-15.8) and paresthesia-based tonic-stimulation (OR = 10.3;95% CI, 1.7-62.0), but not burst or high frequency, were significantly associated with successfultrials. Of note, the number of leads (whether dual or single), pain duration, characteristics, andcategory (nociceptive vs neuropathic) were not significant factors. An interaction between surgicalspine history and lower extremity pain was significantly associated with a positive trial (P = .005).Limitations: This study was limited by its retrospective nature and focus on a patient populationat a single major academic medical center.Conclusions: Paresthesia-based tonic stimulation, age, and surgical history have significanteffects on SCS trials. Prospective and randomized controlled studies may provide deeper insightsregarding impact on costs and overall outcomes.