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Spinal Cord Stimulation for the
Treatment of Chronic Pain
John Talley Parrot, MD
Disclosure Slide
 I have no financial
relationships with any
commercial interest related to
the content of this activity
 I am a faculty consultant for
Medtronics and Synthes / AO
Spine
Just So I Didn’t Forget My Questions Doctor Parrott
Chronic Pain
 Lifetime prevalence > 70%
(Damkot DK, Pope MH, Lord J, Frymoyer JW.The relationship between work history, work environment and low back pain in men. Spine 9:395,
1984.)
 US 1 year prevalence rate—5-20%
(Cunningham LS, Kelsey JL: Epidemiology of musculoskeletal impairments and associated disability. Am J Public Health. 74:574, 19848.Deyo
RA, Tsui-Wu Y-J: Descriptive Epidemiology of low back pain and its related medical care in the United States. Spine 12; 264-268, 1987.)
 Annual direct medical costs $25 billion
(Frymoyer JW, Cats-Baril WL. An overview of incidences and costs of low back pain. Orthop Clin North America 1991; 22:263-71.)
 Most common cause of disability < 45 y/o
 2.4 million disabled
 Return To Work = 0 after 2 yr absence d/t LBP
(Bigos SJ, Bettie MC: The impact of spinal disorders in industry. The Adult Spine. New York, Raven Press, 1991.)
Chronic Pain
 725k lumbar fusions/discectomies 2000
(Agency for Healthcare Research and Quality. Healthcare Cost & Utilization Project (HCUP). Accessed May 10, 2007, at
http://www.ahrq.gov/data/hcup/)
 30k-40k lumbar laminectomy patients/yr obtain
no relief or recurrence of symptoms
(Keane GP. Failed low back surgery syndrome. In: Cole AJ, ed. The low back pain handbook. Phila- delphia: Mosby; 1997:269–81. )
Long-Term Pain Affects Most of Your Patients
 3 out of 4 Americans have experienced chronic or
recurring pain or have a family member who has
experienced such pain
 Almost 62% of pain sufferers have had their pain for a
year or more
 A majority of adults (57%) have experienced chronic or
recurring pain, including 54% of adults aged 18–34
Reference: Americans Talk about Pain, conducted by Peter D. Hart Research Associates for Research!America, August 2003.
Millions of Americans Suffer With Pain…
 50 million Americans are partially or totally disabled by
chronic pain
 9 out of 10 Americans (aged 18 and older) suffer with pain
at least once a month
 77% of pain patients strongly agree that new options are
needed to treat their pain
 50% of Americans (aged 65 and older) suffer daily pain
Reference: Pain in America: A Research Report, conducted by the Gallup Organization for Merck, June 1999.
Epidemiology
 “Failed Back Surgery Syndrome”
 Heterogenous group of disorders
 Specific diagnosis neither implicit or explicit
 Multiple possible explanations
 Persistent/recurrent/new LBP or lower limb pain
 Multiple etiologies
(Slipman - Pain Med 2002, Schoferman -Pain Med 2002, Bernard - Spine 1993, Long J. - NS 1988)
Slipman CW. Etiologies of Failed Back Surgery Syndrome, Pain Medicine 2002;3(3):200-214
Nociceptive Pain
 Somatic pain arises from:
 Bone and joint
 Muscle
 Skin
 Connective tissue
 Aching or throbbing
 Localized
 Visceral pain arises from:
 Visceral organs such as GI tract and
pancreas
 Tumor involvement
 Obstructive
Neuropathic Pain
 Abnormal processing of sensory input by
the peripheral or central nervous system
 Centrally generated pain
 Peripherally generated pain
 Dorsal Root Ganglion (DRG)
 Nerve Root
Neuropathic Radicular Pain
http://www.netterimages.com/image/list.htm?page=2&s=spinal%20cord; image 1317)
Mixed Pain
 Many patients have a combination of both
nociceptive and neuropathic pain
 Disease or trauma has damaged both
nerve cells and other tissues
History of Neurostimulation
 One of the earliest uses of electricity in medicine was for
pain relief.
 Around 15 A.D., Scribonius reported that a torpedo fish
could be used to apply an electrical charge to patients to
relieve pain.
Reference: Gildenberg PL. History of electrical neuromodulation for chronic pain. Pain Medicine. 2006;7(S1):S7-S13
What is Spinal Cord Stimulation?
Therapeutic Algorithm
Third Tier
Second-Tier
Neurostimulation
Surgical Intervention
First Tier
Diagnosis
Physical Therapy
NSAIDS
Analgesics
Imaging
EMG/NCS
Diagnostic blocks
Therapuetic proc.s
Neuromodulation Devices
Allow the delivery of very small, precise doses of electricity
or drugs directly to targeted nerve sites.
Neuromodulation Devices
Electrical Stimulators
Precise delivery of small doses of electricity directly to targeted
nerve sites
Spinal Cord Stimulation (SCS)
Implanted medical device
that delivers electrical
pulses to nerves in the
dorsal aspect of the spinal
cord that can interfere with
the transmission of pain
signals to the brain and
replace them with a more
pleasant sensation called
paresthesia.
CNS Pain Management (Theory)
 Gate Control Theory
 Melzack and Wall, 1968
C FIBER
INHIBITORY
INTERNEURON
AaAb FIBERS
PROJECTION
NEURON
Gate Control Theory
 When sensory impulses are greater than pain impulses
 “Gate” in the spinal cord closes preventing the pain signal
from reaching the brain
Sensory
C FIBER
INHIBITORY
INTERNEURON
Pain
AaAb FIBERS
PROJECTION
NEURON
Gate Theory and SCS
SCS system implanted near dorsal column stimulates the
pain-inhibiting nerve fibers masking painful sensation with a
tingling sensation (paresthesia)
C FIBER
Sensory
SCS
INHIBITORY
INTERNEURON
Gate
Pain
AaAb FIBERS
PROJECTION
NEURON
Tenets of SCS




Comprehensive trial
Customizable system components
Optimized efficiency in programs and design
Team approach to patient care
 Anesthesia Pain Physician
 Orthopedic Spine / Neurosurgeon
 SCS Medical Device Clinical Representatives
Advantages of SCS Therapy





Safe
Testable **
Non-destructive
Mostly reversible
Long-term cost is low
Disadvantages of SCS Therapy
 Refractory on some patients
 Potential equipment failure
 Short-term costs can be high, but are reimburseable via
Medicare, workers compensation, and the private payer
community
 Long term follow-up required via anesthesia pain
management, and / or SCS medical device clinical
representation
 Steep learning curve for procedure
Overall Goals of SCS Therapy
 Position electrode in area of specific neural target
 Generate electrical field at target nerve to create paresthesia that
overlaps painful area(s)
 Program stimulation parameters for maximum effectiveness,
patient comfort, and energy efficiency
 Reduce medication, restore function and improve quality of life
 Return patient to work
Factors Influencing Therapy Success
 Clinical
 Indications
 Pain etiology
 Pain distribution
 Patient factors
 SCS Device
 Sufficient coverage
 Targeting of electrical field
 Sustainability of therapy
27
© 2010 St. Jude Medical, Inc. All rights reserved.
Clinical Factors
 Indication
 Responsive to SCS
 Disease Etiology
 Disease likely to progress should have device with “extra
capacity”
 Pain Distribution
 Multi site and broad pain patterns often require more leads and
electrodes
 Patient Factors
 Anatomy
 Physiology
 Selection
Device Factors
 Stimulation Coverage
 Paresthesia is delivered to entire painful segment(s)
 Precision of Stimulation
 Not delivered to extraneous sites but masks the pain with a
tolerable sensation
 Sustainability of Therapy
 Sustained over the painful anatomical segment
How Are Clinical
Factors Evaluated?
 Patient Selection Process
 Correctly diagnosed
 Failed lower level therapies
 Successfully passed psyche evaluation
 Patient is motivated
 Patient is educated
How Are Device Factors Evaluated?
 During a Temporary SCS Trial
 Leads are implanted
 External power source is used to evaluate





Pain relief
Paresthesia coverage
Power requirements
Programming needs
System requirements (Rechargeable Or Conventional)
SCS Phases
 Trial
 Permanent implant
Trials
 One advantage of SCS over the other pain management
or surgical therapies is that it can be tested on patients
before an SCS device is permanently implanted.
 The trial gives the implanting physician important
information for determining which of the three SCS
systems is appropriate for a specific patient.
Trials
 A spinal cord stimulation trial involves
 A short outpatient procedure during which the
implanting physician places one or more leads in the
space over the spinal cord.
 The patient is awake during the procedure so that he
or she can provide feedback to the physician
regarding exact placement.
 The lead connects to a device that can be worn on a
belt. The device may contain a variety of programs.
Trial System
Trial Lead
Trial Cable
Trial Generator/
Programmer
Length of Trials
 Trial length determined by daily verbal patient verbal
 Anesthesia pain physician staff – daily telephone calls
 SCS clinical representatives – daily telephone calls
and office visit for adjustment intra-trial if needed
 Short-term trials
 2 to 5 days
 Long-term trials
 5 to 7 days
The Patient’s Role in Trials
The patient should:
 Have a working knowledge of the SCS trial device
 Understand movement restrictions
 Reduce bending at the waist
 Reduce lifting over the head
 Understand the sensations to be expected
 Be able to document his or her responses, pain level,
and functional changes
 Be reasonably active
Patient/Device Criteria
Conventional IPG
Rechargeable IPG
Power requirements
Low to moderate
Moderate to high
Frequency
requirements
Low
Low to moderate
Pain
Stable
Likely to progress
Coverage needs
(contacts/leads)
8 contacts on
1 or 2 leads
8 or 16 contacts on
1-4 leads
Compliance
(motivation and ability)
Requires very little
interaction
High—due to
recharging protocol
Competence
(physical or mental)
Appropriate for all levels
Higher level required
Skin sensitivity
Patients with high
sensitivity
Patients with moderate
to low sensitivity
Implant size
Moderate to large sizes
Small to moderate size
Implant longevity
2-7 years
5-10 years
Patient interface
Easier to use
Requires management
Single Or Dual Trial Leads
Paddle Lead Arrays
Tripolar Paddle Array
Penta Five Column Array
SCS Studies
Reduction in pain
Author
No. Patients
Follow-Up
Results
Kumar
410
8 years
74% had ≥ 50% relief
North
19
3 years
47% had ≥ 50% relief
Barolat
41
1 year
50%-65% had good/excel.
relief
Van Buyten
123
3 years
68% had good/excel. relief
Cameron
747
up to 59 mos.
62% had ≥ 50% relief or
significant reduction in pain
scores
Kumar K, Hunter G Demeria D. Spinal Cord Stimulation in Treatment of Chronic Benign Pain: Challenges in Treatment Planning and Present status, a 22-Year Experience.
Neurosurgery. 2006;58:481-496.
North RB,Kidd DH, Farrokhi F,Piantadosi SA. Spinal Cord Stimulation versus Repeated Lumbosacral Spine Surgery for Chronic Pain: a Randomized Controlled Trial in Patients with
Failed Back Surgery Syndrome. Pain.2007;132:179-188.
Barolat G, Oakley JC, Law JD, North RB, Ketick B, Sharan A. Epidural Spinal Cord Stimulation with a Multiple Electrode Paddle Lead is Effective in Treating Intractable Low Back
Pain. Neuromodulation. 2001;4:59-66.
Van Buyten JP,Van Zundert J,Vueghs P, Vanduffel L. Efficacy of Spinal Cord Stimulation : 10 Years of Experience in a Pain Centre in Belgium. Eur J Pain. 2001;5:299-307.
Cameron T. Safety and Efficacy of Spinal Cord Stimulation for the Treatment of Chronic Pain: A 20-Year Literature Review. J Neurosurg Spine. 2004;100(3):254-267.
SCS Studies
Reduction in medication
Author
No. Patients
Follow-Up
Results
North
19
3 years
50% reduced their med use
Van Buyten
123
3 years
>50%reduction in med use
Cameron
766
up to 84 mos.
45% reduced their med use
Taylor
681
n/a
53% no longer needed Analgesics
North RB,Kidd DH, Farrokhi F,Piantadosi SA. Spinal Cord Stimulation versus Repeated Lumbosacral Spine Surgery for Chronic Pain: a Randomized Controlled Trial in
Patients with Failed Back Surgery Syndrome. Pain.2007;132:179-188.
Van Buyten JP,Van Zundert J,Vueghs P, Vanduffel L. Efficacy of Spinal Cord Stimulation : 10 Years of Experience in a Pain Centre in Belgium. Eur J Pain. 2001;5:299307.
Cameron T. Safety and Efficacy of Spinal Cord Stimulation for the Treatment of Chronic Pain: A 20-Year Literature Review. J Neurosurg Spine. 2004;100(3):254-267.
Taylor RS, Van Buyten JP, Buchser E. Spinal Cord Stimulation for Chronic Back and Leg Pain and Failed Back Surgery Syndrome: A Systematic Review and Analysis of
Prognostic Factors. Spine. 2005;30:152-160.
SCS Studies
Improvement in daily activities
Author
No. Patients
Follow-Up
Results
Barolat
41
1 year
As a group, significant improvements in
function and mobility
North
19
3 years
As a group, improvements in a range of
activities
Barolat G, Oakley JC, Law JD, North RB, Ketick B, Sharan A. Epidural Spinal Cord Stimulation with a Multiple Electrode Paddle Lead is Effective in Treating Intractable
Low Back Pain. Neuromodulation. 2001;4:59-66.
North RB,Kidd DH, Farrokhi F,Piantadosi SA. Spinal Cord Stimulation versus Repeated Lumbosacral Spine Surgery for Chronic Pain: a Randomized Controlled Trial in
Patients with Failed Back Surgery Syndrome. Pain.2007;132:179-188.
SCS Studies
Return to work
Author
No. Patients
Follow-Up
Results
Van Buyten
123
3 years
31% returned to work
Taylor
1,133
n/a
40% returned to work
Dario
23
3 years
35% returned to work
Van Buyten JP,Van Zundert J,Vueghs P, Vanduffel L. Efficacy of Spinal Cord Stimulation : 10 Years of Experience in a Pain Centre in Belgium. Eur J Pain. 2001;5:299-307.
Taylor RS, Van Buyten JP, Buchser E. Spinal Cord Stimulation for Chronic Back and Leg Pain and Failed Back Surgery Syndrome: A Systematic Review and Analysis of
Prognostic Factors. Spine. 2005;30:152-160.
Dario A, Fortini G, Bertollo D, Bacuzzi A, Grizzetti C, Cuffari S. Treatment of Failed Back Surgery Syndrome. Neuromodulation. 2001;4:105-110.
Questions?