Spinal Cord Stimulation: Indications and Patient Selection

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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
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Disclosures

• Consultant
• Boston Scientific Neuromodulation
• Medtronic Navigation

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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

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Indications for Surgery

• Compressive lesion
• Associated radiculopathy
• Demonstrable neurologic deficit
• Clear instability / deformity

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CRPS Diagnostic Criteria

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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.
20061-11.
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Surgical Contraindications

• Thecal sac compression by tumor
• Significant spinal deformity
• Severe emaciation
• Significantly low WBC, plt
• Coagulopathy
• Ongoing infection
• Unsuccessful trial

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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

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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

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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

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Other Treatments

• Should proceed in parallel
• Psychological counseling
• Behavioral treatments
• Physical therapy and conditioning
• Vocational counseling and rehab
• Implantables cant fix everything!

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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

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Pain Psychology

• Spine surgery success in the presence of
• Childhood physical or sexual abuse,
• Emotional neglect/abuse
• Abandonment
• Chemically dependent parents
• Factors Surgical Success
• 1 95
• 1-2 73
• 3 or more 15

(Shofferman et al., 1992)
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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.

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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

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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.

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Preop imaging is essential

• You would never do any other spine case without
  adequate preop imaging DONT START NOW
• Preop imaging makes sure something asymptomatic
  doesnt become symptomatic
• Aids in counseling patient preop if procedure
  needs to be altered to deal with anatomic issue

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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

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Thank you for coming!
E-mail jrosenow_at_nmff.org
Phone [phone]