Neurostimulation for Pain:
Neurosurgical Considerations
Joshua M. Rosenow, MD, FACS
Director, Functional Neurosurgery
Associate Professor, Department of Neurosurgery
Northwestern Memorial Hospital
Northwestern University Department of Neurosurgery
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
*North, et al. Stereotact Funct Neurosurg 1994;62:267-272.
Northwestern University Department of Neurosurgery
Patient Factors
Set appropriate expectations!!!!
 Takes time, but will be worth the investment
Prepare patients for the procedure
Involve them in the process
 i.e. IPG placement
Northwestern University Department of Neurosurgery
Surgical Contraindications
 Thecal sac compression/significant spinal stenosis
 Significant spinal deformity
 Severe emaciation
 Significantly low WBC, plt
 Coagulopathy
 Ongoing infection
 Inability to assess patient response to trial
 Psychological contraindications
 Patient compliance issues
 Medication abuse issues
 Unsuccessful trial
Northwestern University Department of Neurosurgery
General Principles
 Adequate length of trial
 Choose appropriate hardware
 Simulate everyday life during trial, within limits
 Confirm location and ensure stability of electrode
 Prevent infection
 Prepare for permanent implant
 Permanent system should be stable, flexible and
convenient
 Prepare for revisions
Northwestern University Department of Neurosurgery
MAC vs. GETA
 Airway/body habitus
 Comorbidities
 Procedure to be performed/region of operation
 Anticipated intraoperative difficulties
 Need for intraoperative verification of coverage
 Patient preference
 Patient ability/willingness to cooperate
 If GETA - consider neuromonitoring for protection and confirmation
Northwestern University Department of Neurosurgery
Why use paddles?
 Previous difficulties with perc leads
 Preference of implanter
 ?lower current requirement
 ?less interference by epidural fat
Northwestern University Department of Neurosurgery
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.
Northwestern University Department of Neurosurgery
Paddle Leads
Northwestern University Department of Neurosurgery
Laminotomy Lead Placement
 Plan incision centered 1 disc space below
desired entry point
 Incision centered on T10-11 will lead to entry at T9-10
and paddle will cover T8-9 bodies
 Rongeur both upper and lower spinous processes to
flatten angle
 Small central lamintomy through ligamentum flavum
 Carefully dissect epidural space and insert electrode
 Avoid pressure on spinal cord
 Securely anchor to deep tissues
Northwestern University Department of Neurosurgery
Paddle issues
 Where does the paddle go?
 Assessing canal adequacy for paddle
 Clearing the epidural space
 The paddle won’t go straight
Northwestern University Department of Neurosurgery
Guess the level!
Northwestern University Department of Neurosurgery
Communication is key
T9
T10
Northwestern University Department of Neurosurgery
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
Northwestern University Department of Neurosurgery
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
Northwestern University Department of Neurosurgery
Paddle issues in the OR
Dissecting epidural space
 Careful
 You’re a surgeon – use surgical tools
No – paddle lead, passing device
Yes – dural separator, narrow tip malleable brain ribbon
Anywhere but straight
 Straight paddle in curved space
 Epidural adhesion
 Unilateral extension vs. “reach around” laminotomy
Northwestern University Department of Neurosurgery
Epidural fibrosis
 Careful dissection
 Use appropriate instruments
 Don’t over-reach
 Decompress if you need to do so
 Suture paddle to dura if possible
 Fibrin glue
 Postop abdominal pain
Northwestern University Department of Neurosurgery
Complication avoidance
 Don’t be overzealous
 Don’t push a bad situation
 If it won’t go, it won’t go…
 Caution when dissecting laterally – epidural veins
 Poor coverage despite radiographic adequacy
 check trial fluoros
 make sure c-arm aligned in both planes
Northwestern University Department of Neurosurgery
Don’t be THAT surgeon
 Paddle placed under GETA
 Awoke with right thoracic radicular pain
 Never had good coverage with stim
 Surgeon told him to “wait a year and see
if the coverage and pain improve”
Northwestern University Department of Neurosurgery
Don’t make more cases!
Northwestern University Department of Neurosurgery
To Extend or Not to Extend
 PRO
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Adds slack to system
May make revision less invasive
May be needed to adapt electrodes to IPG
Needed for “permanent trial”
 CON
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Another electrical connection
Another wire that may break
Connector adds bulk and may not be suitable for some locations
Direct connection to IPG may reduce slack in system and add tension to
electrode
 In either case, there should be a relaxing loop of electrode
in the electrode incision site
Northwestern University Department of Neurosurgery
IPG Considerations
 Location location location
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Patient comfort
Cosmesis
Ease of remote interface
Ease of recharger interface (if rechargeable)
Ease of implant
Ease of revision
 Rechargeable vs. Primary cell
Northwestern University Department of Neurosurgery
Possible IPG Locations
 Buttock
 Infraclavicular
 Cervical or lumbar SCS
 ONS
 Peripheral LE stimulation
 Axillary
 ONS
 Cervical SCS
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Trigeminal
ONS
DBS/MCS
Cervical SCS
UE peripheral stimulation
 SQ lower extremity
 Abdomen
 DBS/MCS
 ONS
 SCS
Northwestern University Department of Neurosurgery
Conclusions
 Rational treatment plan improves outcomes
 Good patient selection important
 Technique is key, as always
 Goal: not “do implants” but TREAT PAIN
Northwestern University Department of Neurosurgery
Thank you for coming!
E-mail: jrosenow@nmff.org
Phone: 312-695-0495
Northwestern University Department of Neurosurgery
Northwestern University Department of Neurosurgery