Spinal Cord Stimulator Trial in a Patient on Chronic Opioids with Psychological Comorbidities
A 52-year-old man with failed back surgery syndrome after L4-L5 fusion has persistent radicular leg pain (7/10) despite physical therapy, gabapentin 600 mg three times daily, and oxycodone 20 mg four times daily. He has depression (PHQ-9 = 16), catastrophizing, and is on disability. He requests a spinal cord stimulator (SCS) trial. His MRI shows no recurrent disc herniation or hardware failure. He has completed a psychological evaluation that noted "high distress, but engaged and willing to participate in CBT."
1. Assess his candidacy for an SCS trial and identify factors that must be addressed before proceeding.
Read the worked answer
- Favorable: Neuropathic leg-predominant pain, failed conservative therapy, no surgical target, and willingness to engage in behavioral treatment.
- Concerning: High depression/catastrophizing, high opioid dose, and disability status - these predict poorer outcomes and require optimization, not automatic exclusion.
- Plan: Initiate CBT and consider psychiatric treatment; optimize opioids where possible; set realistic goals (functional improvement, not complete pain elimination).
Judgment call: Proceed only with a multidisciplinary plan and clear expectations; document shared decision-making.
2. Define success criteria for the trial and how you would handle a partial response.
Read the worked answer
- Success criteria: Typically ≥50% pain reduction in the target area plus functional improvement, assessed with a pain diary and validated measures.
- Partial response: Optimize programming, reassess lead placement, and consider extending the trial if safe. Avoid converting to permanent implant based solely on a marginal response.
Judgment call: A partial response with good function may justify implantation in selected patients, but the decision should be individualized and documented.