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Spinal Cord Stimulation: Indications and Patient Selection. Joshua M. Rosenow, MD, FACS Associate Professor of Neurosurgery Director , Functional Neurosurgery Northwestern Memorial Hospital. Disclosures. Consultant: Boston Scientific Neuromodulation Medtronic Navigation.
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Spinal Cord Stimulation: Indications and Patient Selection Joshua M. Rosenow, MD, FACS Associate Professor of Neurosurgery Director, Functional Neurosurgery Northwestern Memorial Hospital
Disclosures • Consultant: • Boston Scientific Neuromodulation • Medtronic Navigation
FBSS Etiologies • Poor patient selection • Abnormal psychometrics • Chronic pain behavior • Unreachable expectations • Incorrect diagnosis • Wrong procedure • Wrong level or site • Poor technique • Nerve root injury • Iatrogenic instability or flat back syndrome • Pseudarthrosis • Incomplete decompression or incomplete correction of deformity • Progressive disease • Recurrent disk herniation or spinal stenosis • Transition syndrome
Indications for Surgery • Compressive lesion • Associated radiculopathy • Demonstrable neurologic deficit • Clear instability / deformity
Revised Diagnostic Criteria • Pain and sensory changes disproportionate to the injury in magnitude or duration • At least 1 symptom in 3 or more categories and 1 sign in 2 or more categories • Sensory • Vasomotor • Sudomotor/edema • Motor/trophic Harden RN and Bruehl SP. Introduction and diagnostic considerations. Complex Regional Pain Syndrome: Treatment Guidelines. RSDSA press. 2006:1-11.
Surgical Contraindications • Thecal sac compression by tumor • Significant spinal deformity • Severe emaciation • Significantly low WBC, plt • Coagulopathy • Ongoing infection • Unsuccessful trial
SCS: Patient Selection • Pain syndrome amenable to stimulation • Radicular preferable to axial • Neuropathic preferable to nociceptive • Failed reasonable medical management • Several pharmacologic classes • Dose titration until adverse side effects or lack of response noted • Surgical disease ruled out • Reoperation vs. stim? • Not surgical candidate? • Pain psychological evaluation
Patient Factors • Set appropriate expectations!!!! • Takes time, but will be worth the investment • They need to understand this is not a cure! • Seeing the patient multiple times before moving to a trial helps gauge their goals of therapy and probable compliance level
Patient Factors • Can they be a reliable partner with a subjective therapy? • Can they give appropriate feedback in the OR? • Can they manage the device? • Rechargeable vs primary cell IPG
Other Treatments • Should proceed in parallel • Psychological counseling • Behavioral treatments • Physical therapy and conditioning • Vocational counseling and rehab • Implantables can’t fix everything!
Psychosocial Factors • Present in ALL chronic pain patients • Can include: • Depression • Personality disorders • Drug and alcohol problems • Return to work issues • Social and family discord • Many others
Pain Psychology • Spine surgery success in the presence of: • Childhood physical or sexual abuse, • Emotional neglect/abuse • Abandonment • Chemically dependent parents: # FactorsSurgical Success 1 95% 1-2 73% 3 or more 15% (Shofferman et al., 1992)
Predictive value of psychological testing • Many studies have examined the value of psychological testing in predicting success with SCS • Daniel et al calculated an 80% accuracy rate using the MMPI and BDI for predicting success. • Burchiel et al. found that the BDI score and mania scale on the MMPI emerged as predictors. Less helpful in a subsequent study. • Long et al reported a 33% success rate in unscreened patients compared with 70% in screened patients.
Trial Techniques Trial implant Easiest Fastest Remove electrode in office Low prob candidates If multiple choices or procedures debated If location not suitable for trial extension Requires reimplant of electrode at permanent implant “Permanent Trial” • Permanent implant easier • Remove electrode in OR • If finding therapeutic location 2nd time will be difficult • If implant technique difficult or invasive • If general anes needed for permanent system
Paddle Trials • Lumbar fusion or laminectomy precluding percutaneous insertion • Inability to access the epidural space percutaneously • Bony anatomy • Obesity • Prior procedure in the region of the implant • Tumor resection, etc.
Preop imaging is essential • You would never do any other spine case without adequate preop imaging – DON’T START NOW • Preop imaging makes sure something asymptomatic doesn’t become symptomatic • Aids in counseling patient preop if procedure needs to be altered to deal with anatomic issue
Preop imaging is essential • Where is the cord??? • The cord may not respect the spinal column midline • Paddle may look great on fluoro and not provide adequate coverage
Thank you for coming! E-mail: jrosenow@nmff.org Phone: 312-695-0495