Updates in Neuromodulation 2020 Kenneth B. Chapman, MD Director, - - PowerPoint PPT Presentation

Updates in Neuromodulation 2020

Kenneth B. Chapman, MD

Director, Pain Medicine Staten Island University Hospital Assistant Clinical Professor, NYU Langone Medical Center Adjunct Assistant Professor, Zucker School of Medicine at Hofstra/Northwell

Disclosures:

None

The Evolution of Neurostimulation for Pain

1967-1999 1999-2007 2007-2013 2013-2015

1 Company 4 Contact lead 3 Companies 8 contact lead Improvements in: Battery Leads Programming Paresthesia free stimulation introduced

Psychological Improvements of Burst Expanded Indications with HF-10 Return to Paresthesia Based Waveform Focus moves to Therapies other than DH

The Move to Paresthesia Fr Free Sti timulati tion

~Differ erences i s in n Paresthesi sia Fr Free B ee Bur urst~

Details of Passive Recharge Burst Stimulation Pulse Train

Studied Passive Burst Stimulation Parameters

Interburst Burst Rate 40 Hz Duration 25 ms Intra-Burst Rate 500 Hz Pulse Width 1 us Burst Train 5 pulses Burst Train Duration 9 us Quiescence Period 16 us

Interburst Frequency 40Hz Intraburst Frequency 500 Hz Pulse Amplitude (<60% threshold) Burst Train 9 µS Pulse Width 1000 µS Charge Balance Interval 16 µS

Patient Specific Parameters

Interburst Burst Rate Variable Duration Variable Intra-Burst Rate Variable Pulse Width Variable Burst Train 4-9 pulses

Dirk De Ridder et al. All bursts are equal, but some are more equal (to burst firing):burstDR stimulation versus Boston burst stimulation. Expert Review of Medical Devices DOI: 10.1080/17434440.2020.1736560

 IPG systems do not allow passive

recharge

 Active charge balance by flipping

anode and cathode

Intra and Extracellular Cellular Differences with Burst Firing

Burst definition

A burst is a train of action potentials that occurs during a ‘plateau’ or ‘active phase’, followed by a period of relative quiescence called the ‘silent phase’

Crunelli 2018 Weiergraeber 2010

Clustered tonic firing Burst firing

Weiergräber M, Stephani U, Köhling R. Voltage-gated calcium channels in the etiopathogenesis and treatment of absence epilepsy. Brain Res Rev. 2010 Mar;62(2):245-71. Crunelli V, Lőrincz ML, Connelly WM, David F, Hughes SW, Lambert RC, Leresche N, Errington AC. Dual function of thalamic low-vigilance state oscillations: rhythm-regulation and plasticity. Nat Rev Neurosci. 2018 Feb;19(2):107-118.

Calcium Induced Bursting leads to non-linear responses

Non-linear post- synaptic response

Synaptic Input EPSP Response

Bursts

Linear 1:1 response Tonic

Sherman SM. Tonic and burst firing: dual modes of thalamocortical relay. Trends Neurosci. 2001 Feb;24(2):122-6 Falowski S. An Observational Case Series of Spinal Cord Stimulation Waveforms Visualized on Intraoperative Neuromonitoring. Neuromodulation. 2019. 22: 219-228

Active Recharge Burst Linear 1:1 response

Passive Recharge Burst Non-linear post-synaptic response

Burst type differences in Rodent Models

1.5 mA (±0.9) 62% 0.6 mA (±0.4) 91%

Passive Recharge Burst:

LOWER AMPLITUDES ARE BETTER

Active Recharge Burst:

HIGHER AMPLITUDES ARE BETTER

paresthesia free Sunburst optimization Kent et al. Burst & High-Frequency Spinal Cord Stimulation Differentially Effect Spinal Neuronal Activity After Radiculopathy. Ann Biomed Eng. 2020 Jan;48(1):112-120. Epub 2019 Aug 5. PMID: 31385104. Meuwissen et al. Conventional-SCS vs. Burst-SCS and the Behavioral Effect on Mechanical Hypersensitivity in a Rat Model of Chronic Neuropathic Pain: Effect of Amplitude. Neuromodulation. 2018 Jan;21(1):19-30. doi: 10.1111/ner.12731. Epub 2017 Nov 27. PMID: 29178358. Leong et al. Potential Therapeutic Effect of Low Amplitude Burst Spinal Cord Stimulation on Pain. Neuromodulation. 2019 Dec 18. doi: 10.1111/ner.13090. Epub ahead of print. PMID: 31854070. Quindlen-Hotek JC, Kent AR, De Anda P, Kartha S, Benison AM, Winkelstein BA. Changes in Neuronal Activity in the Anterior Cingulate Cortex and Primary Somatosensory Cortex With Nonlinear Burst and Tonic Spinal Cord Stimulation. Neuromodulation. 2020 Jul;23(5):594-604. doi: 10.1111/ner

Average MTs were significant different for active recharge burst (37 ± 21 μA) compared to passive recharge burst (200 ± 61 μA).

Interm ittent Dosing with Passive Burst

Results

Patient Population and design

• Prospective, open label, multicenter, feasibility trial
• Chronic intractable back and/or leg pain patients, no prior history of SCS
• N=50 patients
• 1, 3 and 6 month follow-up
• 5 dosing protocols:
• 30 on / 360 off
• 30 on / 240 off
• 30 on / 150 off
• 30 on / 120 off
• 30 on / 90 off

45.8% of patients utilized program with lowest dose setting 100% of patients received clinically relevant pain relief with dosed settings Patients are used therapy for six hours or less per day

Deer et al. Novel Intermittent Dosing Burst Paradigm in Spinal Cord Stimulation.Neuromodulation: Technology at the Neural Interface, 2020. DOI: 10.1111/ner.13143

Summary: Not all bursts are equal

Passive recharge Burst ≠ Active recharge = Tonic stimulation

Does it matter though?

Passive Burst Stimulation Active Burst Stimulation

Descending pain inhibitory (pgACC, PHC) Descending pain inhibitory (pgACC, PHC) Lateral pain pathway (SSC) Non-linear stronger activator Lateral pain pathway (SSC) Medial pain pathway (rACC/DLPFC) Rerouting/multiplexing Medial pain pathway (rACC/DLPFC) Normalizes pain promoting/pain suppressing balance Decreases pain promoting/pain suppressing balance Dopamine? GABA Not via dorsal columns Dorsal columns

Activation map

Blood Oxygen Level-Dependent (BOLD)Functional MRI

Medial Pathway Lateral Pathway

Medial pathway activation (emotional aspects) with Active Recharge Burst Lateral pathway activation (objective aspects) with Active Recharge Burst

De Ridder et al.Burst spinal cord stimulation for limb and back pain. World Neurosurg. 2013 Nov;80(5):642-649.e1. doi: 10.1016/j.wneu.2013.01.040. Epub 2013 Jan 12. Meuwissen K et al. Active Recharge Burst and Tonic Spinal Cord Stimulation Engage Different Supraspinal Mechanisms: A Functional Magnetic Resonance Imaging Study in Peripherally Injured Chronic Neuropathic Rats. Pain Pract. 2020 Jun;20(5):510-521. Pawela CP, Kramer JM, Hogan QH. Dorsal root ganglion stimulation attenuates the BOLD signal response to noxious sensory input in specific brain regions: Insights into a possible mechanism for analgesia. Neuroimage. 2017 Feb 15;147:10-18.

Acute noxious sensory stimulation caused robust BOLD fMRI response in brain regions previously associated with sensory and pain-related response, such as the primary/secondary somatosensory cortex, retrosplenial granular cortex, thalamus, caudate putamen, nucleus accumbens, globus pallidus, and amygdala.

Patient Preference in Active Recharge Burst Stimulation

Patient preference (proportion of patients) based on free use of different programs. (N= 250)

Proportion

• f patients

Proportion

• f waveforms

0% 20% 40% 60% 80% 100% Tonic Burst no pref Preference (%) Tonic Burst no pref

• 1. Berg AP, Mekel-Bobrov N, Goldberg E, Huynh D, Jain R. Utilization of multiple spinal cord stimulation (SCS) waveforms in chronic pain patients. Expert Rev Med Devices. 2017 Aug;14(8):663-668.
• 2. Deer et al. Success Using Neuromodulation With BURST 2.(SUNBURST) Study: Results From a Prospective, Randomized Controlled Trial Using a Novel Burst Waveform. Neuromodulation. 2018 Jan;21(1):56-66.
• 3. Schu et al. A prospective, randomized, double-blind, placebo-controlled study to examine the effectiveness of burst spinal cord stimulation patterns for the treatment of failed back surgery syndrome.
• Neuromodulation. 2014;17:443–450.

0% 20% 40% 60% 80% 100% Tonic Burst no pref Preference (%) Tonic Burst no pref 2

3

1

Multifidus Stimulation for Low Back Pain

Multifidus

Muscle Control Impairment and Low Back Pain

Freeman et al. The role of the lumbar multifidus in chronic low back pain: a review. PM R. 2010 Feb;2(2):142-6 Panjabi M. Clinical spinal instability and low back pain. J Electromyogr Kinesiol. 2003 Aug;13(4):371-9. Kader et al. Correlation between the MRI changes in the lumbar multifidus muscles and leg pain Clin Radiol, 55 (2000), pp. 145-149

• Pain from muscle strain and injury can lead to muscle control disruption and weakening.
• Atrophied multifidus is seen in 80% of CLBP patients.
• Unstable joints can move outside their ‘pain-free range’ resulting in more pain and reinjury leading to

a continued cycle of chronic pain.

Severe multifidus atrophy (more than 50% of CSA of muscle replaced with fat) Moderate multifidus muscle atrophy (>10% but <50% of CSA of muscle replaced with fat). Mild multifidus muscle atrophy, (less than 10% of CSA of muscle replaced with fat).

ReActiv8 Device

Multifidus

ReActv8-A Baseline Characteristics

• Younger patients
• Pain >10 years
• Mod/severe pain
• Low end severe disability
• 72% on opioids

Deckers et al.New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial.

• Neuromodulation. 2018 Jan;21(1):48-55.

Mean Clinically Important Difference (MCID)

“…. The smallest difference in score in the domain of interest which patients perceive as beneficial and which would mandate, in the absence of troublesome side effects and excessive cost, a change in the patient’s management.”

• This definition involved two constructs

1) Minimal amount of patients reported change 2) Something significant enough to change patient management.

LBP VAS

1. Dworkin et al. Interpreting the clinical importance of treatment outcomes in chronic pain clinical trials: IMMPACT recommendations. The Journal of Pain. 2008. 9(2), 105-21. 2. Ostelo et al. Interpreting change scores for pain and functional status in low back pain towards international consensus regarding minimal important change. Spine. 2008. 33(1), 90-4 3. Soer et al. Clinimetric properties of EuroQol-5D in patients with chronic low back pain. Spine Journal. 2012. 12(11), 1035-1039

EQ-5 ODI

% reached VAS MCID (Δ2) % reached ODI MCID (Δ10) % reached EQ-5 MCID (Δ0.03)

Outcomes

Adverse Events at 1 year

• 47 implants using 94 leads used
• high impedance was observed on at least one conductor in 44 leads in 28 subjects.
• Of the total of 28 implants (53% total) with high impedance observations:
• 7 were reprogrammed using electrode configuration successfully.
• 21/47 (40%) of the 28 subjects could not be salvaged
• 13 (24.5%) had surgical revision to implant new leads.
• 3 subjects elected to continue therapy with unilateral stimulation.
• 3 had the system turned off.
• 2 had the system explanted.

The most frequent AEs (57%) were 1) loss of stimulation (23 AEs in 17 subjects- 33%) 1 migration that led to loss of stimulation 2) pocket discomfort (13 AEs in 12 subjects) 3) Undesired sensations in the target area (seven AEs in six subjects). The remaining 33 related AEs occurred at rates of 1–5%.

Closed Loop Feedback*

*A paresthesia based therapy

Closed Loop Concept

Malagu, N. Introductory Chapter: Linkages between Pharmacokinetics and Adverse Effects of Drugs. Published: May 23rd 2018. DOI: 10.5772/intechopen.76511 Miller et al., 2016; Schade et al., 2010 Bradley, Kerry. The Technology: The Anatomy of a Spinal Cord and Nerve Root Stimulator: The Lead and the Power Source. PAIN MEDICINE Volume 7, Number S1. 2006

Voltage-controlled (VC) systems:

• Voltage (V) is fixed; variations in

impedance (R) cause a change in current. Current-controlled (CC) systems:

• the current (I) is set; variations

in impedance(R) cause a change in voltage.

Ohm’s Law

Posture changes in Fixed Output (Open-loop)

Closed Loop SCS Avalon Study 12 Month Data

Russo et al. Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study. Neuromodulation. 2018 Jan;21(1):38-47. doi: 10.1111/ner.12684. Epub 2017 Sep 18. PMID: 28922517.

• 134 pts. trunk and limb pain
• ECAP-controlled closed-loop vs.

conventional SCS

• 1 YearPrimary objective:
• noninferiority closed-loop stimulation

determined by proportion of subjects with ≥50% reduction in overall trunk and limb pain and no increase in pain medications at 3-month visit

• If noninferiority met, superiority

tested

• IMMPACT measurements

Mekhail et al. Evoke Study Group. Long-term safety and efficacy of closed-loop spinal cord stimulation to treat chronic back and leg pain (Evoke): a double-blind, randomised, controlled trial. Lancet Neurol. 2020 Feb;19(2):123-134.

Closed Loop Evoke RCT

Supplement to: Mekhail N, Levy RM, Deer TR, et al. Long-term safety and efficacy of closed-loop spinal cord stimulation to treat chronic back and leg pain (Evoke): a double-blind, randomised, controlled

• trial. Lancet Neurol 2019; published online Dec 20. http://dx.doi.org/10.1016/S1474-4422(19)30414-4.

Closed Loop Avalon 1 yr Closed Loop Evoke RCT

Diff fferential Target Mult ltip iplexed SCS SCS

Glial Cell Stimulation

Astrocytes are the most abundant and diverse glial cells present in

the CNS. They are known for the maintenance of the blood–brain

• barrier. Yet, more importantly, they maintain the working

environment/ extracellular environment of neurons. They do this by controlling the levels of neurotransmitter around synapses (GABA/inhibitory and Glutamate/excitatory).

Oligodendrocytes produce the fatty substance called myelin, which

is wrapped around axons as a layer of insulation. Similar in function to insulation layers around power cables, the myelin sheath allows electrical messages to travel faster. Research has shown that when

• ligodendrocytes are depolarized (by direct electrical manipulation),

the latency of impulse conduction through the axons it ensheathes rapidly decreases (Glutamatergic axons and GABAergic axons).

Microglia are the brain’s immune cells, serving to protect it against

injury and disease. Microglia identify when something has gone wrong and initiate a response that removes the toxic agent and/or clears away the dead cells. Microglia have distinct phenotypes.

Dormant Microglia: M2 State

Phase 1 (resting) Phase 2 (activated) Quite specific:

modulation of 1 specific state

• f 1 specific glial cell.

DTM Feasibility Study: 25 patients open label

5 10 Baseline Conv SCS DTM-SCS

2.4 4.1 7.2

Back Pain Reduction

P-value < 0.0001 1.7 points in additional back pain relief

0% 50% 100% Conv SCS DTM-SCS

80% 50%

Back Pain Responder(>50%)

Fishman et al. Prospective, Multicenter Feasibility Study to Evaluate Differential Target Multiplexed Spinal Cord Stimulation Programming in Subjects With Chronic Intractable Back Pain With or Without Leg Pain. Pain Pract. 2020 Sep;20(7):761-768. doi: 10.1111/papr.12908. Epub 2020 Jun 2. PMID: 32462791.

N=25 N=24 N=20 N=20 N=20

25 patients 1 week trial 4 days of each

DT DTMTM

TM SCS C

Clin linic ical E l Evid idence: Ran andomized Con

• ntroll

lled T Tria ial l (Jun une 2 e 201 018 to Da Date) e)

Objective:

Long-term evaluation of effectiveness of DTM SCS programming approach in patients with chronic intractable low back pain with or without leg pain in comparison to standard SCS programming

Design:

Multicenter (12 sites across the U.S.), prospective, post-market, open-label, randomized, controlled: 1:1 Randomization – Test Arm: DTM-SCS; Control Arm: Standard SCS 3-months primary endpoint, 12-months follow up Primary outcome: Responder rate (subjects with ≥50% back pain relief) Device: IntellisTM system (Medtronic) Programming: For Conventional SCS: Medtronic representatives For DTM SCS: Stimgenics representatives (study sponsor)

80% 51%

0% 20% 40% 60% 80% 100% DTM_SCS Conv-SCS

BACK PAIN – RESPONDER RATE

Superior P = 0.0010 (ITT)

N=43 N=47 N=55

Fishman M, Cordner H, et al. DTM™ SCS RCT 12-month Data Results. Presented at a Medtronic webinar, jointly supported by the North American Neuromodulation Society (NANS), World Institute of Pain(WIP), and the American Society for Pain and Neuroscience (ASPN). October 19, 2020. Webinar available on society websites.

Dorsal Root G t Ganglion S Sti timulati tion Mec echanis isms s of

• f Action

Increase Filtering at the T-Junction of Primary Sensory Neurons

• The T-junction acts as a low-pass filter such that stimulation can inhibit the propagation of action potentials

Gemes et al. Failure of action potential propagation in sensory neurons: mechanisms and loss of afferent filtering in C-type units after painful nerve injury. J Physiol. 2013 Feb 15;591(4):1111-31 Chao D, Zhang Z, Mecca CM, Hogan QH, Pan B. Analgesic dorsal root ganglionic field stimulation blocks conduction of afferent impulse trains selectively in nociceptive sensory afferents. Pain. 2020 Jul 8.

Neuronal Soma

Alternative Mechanisms in DH?

• Less likely GABA
• Subthreshold
• 1 Hz longer wash out
• Can be effective across frequencies
• Potential for less habuation6

DRG-S

1. Stiller et al.Release of gamma-aminobutyric acid in the dorsal horn and suppression of tactile allodynia by spinal cord stimulation in mononeuropathic rats. Neurosurgery. 1996;39(2):367- 375. 2. Pluijms et al. The effect of spinal cord stimulation frequency in experimental painful diabetic

• polyneuropathy. Eur J Pain. 2013;17(9):1338-1346. doi:10.1002/j.1532-2149.2013.00318.x

3. Koetsier et al. Effectiveness of dorsal root ganglion stimulation and dorsal column spinal cord stimulation in a model of experimental painful diabetic polyneuropathy. CNS Neurosci Ther. 2019;25(3):367-374. doi:10.1111/cns.13065 4. Koetsier et al. Dorsal Root Ganglion Stimulation in Experimental Painful Diabetic Polyneuropathy: Delayed Wash-Out of Pain Relief After Low-Frequency (1Hz) Stimulation.

• Neuromodulation. 2020;23(2):177-184. doi:10.1111/ner.13048

5. Koetsier et al. Mechanism of dorsal root ganglion stimulation for pain relief in painful diabetic polyneuropathy is not dependent on GABA release in the dorsal horn of the spinal cord. CNS Neurosci Ther. 2020;26(1):136-143. doi:10.1111/cns.13192 6. Levy et al. Therapy Habituation at 12 Months: Spinal Cord Stimulation Versus Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome Type I and II [published online ahead of print, 2019 Sep 5]. J Pain. 2019;S1526-5900(18)30681-3

Low back pain

New York & New Jersey Pain Medicine Symposium 2019

Evolving Advanced Pain Therapies

Study # of pts Follow up Outcome Measures Results: Efficacy for Pain Intensity Results: Adverse Events

Chapman (2020)

17 1, 3, 6, 12 months (8.3m avg) VAS,ODI, EQ-5, SF- 36 VAS 9 -> 2 EQ-5 0.3 -> 0.84, ODI 68 -> 14, impressive SF 36 improvements 3 lead migration. 1 genertpr site pain

Kallewaard (2019)

Discogenic LBP

14 1, 3, 6, 12 months VAS, ODI, EQ-5, 1 year: VAS 68% reduction 7.2 to 2.3. ODI 42.1 to 16.6 EQ-5 o.61 to 0.84 4 Lead migrartion, 3 lead fractures, 3 pain at generator site

Kallewaard (2019)

Post Discectomy LBP

11 1,3,6,12 months VAS, BIT VAS 8.64 -> 2.4 BPI 7.16 -> 2.78 EQ5 0.34 ->0.82 ODI 46.1 -> 19.2 2 exit secondary to poor relief

Huygen (2019)

12 1 week, 1, 3, 6, and 12 months VAS, BPI, POMS, EQ-5, AEs Baseline LBP VAS: 74 VAS at 12 months: 40, reduction by 45.5%, 4 SAE (33%) temporary loss of strength, PDH, bladder infection,

• depression. 2 AEs (16.7%): IPG

discomfort, infection, 4 revisions (25.0%)

Weiner (2016)

11 2,4,6 weeks VAS, stimulation amplitude, Aes 50% reduction in VAS: in 7/11 (63%) Average VAS overall decrease 59.9%, regardless placement No SAEs

World Institute of Pain Miami Annual Conference & Cadaver Workshop

February 14-16, 2020 Miami Florida

Chapman et al. T12 Dorsal Root Ganglion Stimulation to Treat Chronic Low Back Pain: A Case Series. Neuromodulation. 2020 Feb;23(2):203-212 Kallewaard et al. A Prospective Study of Dorsal Root Ganglion Stimulation for Non-Operated Discogenic Low Back Pain. Neuromodulation Jan 9 2019 Kallewaard et al. Prospective Cohort Analysis of DRG Stimulation for Failed Back Surgery Syndrome Pain Following Lumbar Discectomy. Pain Pract. 2019 Feb;19(2):204-210. Huygen et al. Stimulation of the L2-L3 Dorsal Root Ganglia Induces Effective Pain Relief in the Low Back. Pain Pract. 2018 Feb;18(2):205-213.

The P he Pathways a s and nd P Processe esses s Und Underlying S Spi pinal T Transm smissi sion o

• f Low Back Pain:

Obs bservations ns f from Dorsal R Root Gang nglion S n Stimul ulation n Trea eatmen ent

1.A 1.B 3.B 2.A 2.B 6. 5. 4. 7. 3.A

Chapman et al. The Pathways and Processes Underlying Spinal Transmission of Low Back Pain: Observations From Dorsal Root Ganglion Stimulation Treatment. Neuromodulation. 2020 Apr 23.

Kenneth B. Chapman, MD, Tariq Yousef, MD, Kris C. Vissers, MD PhD, Noud van Helmond, MD, Michael Stanton-Hicks, MD. Very Low Frequencies Maintain Pain Relief from Dorsal Root Ganglion Stimulation: An Evaluation

• f DRG-S Frequency Tapering. Neuromodulation. Accepted. Pending publication.

(Hz) (µs) (mA) Charge/s (µC/s) (Hz * µs * mA) DRG-S pre-taper 16 260 0.40 1.6 DRG-S post-taper 4 260 0.54 0.56 Tonic SCS* 50 400 3.5 7 HF10* 10,000 30 2.5 75

Frequency

The Effects of Duty Cycling with DRG-S

• Randomized double blinded crossover study using stimulation ‘on’ and ‘off’ paradigms. 15 patients.
• Three programs- 2 weeks baseline optimized. All programs same other than the cycling of energy

delivery:

• Continuous delivery
• 1:1 – cycle of one minute on, on minute off
• 1:2 – cycle of one minute on, two minutes off
• Results: No change in VAS, ODI. And EQ-5
• Patient preference: 2:1 6 patients, continuous 6 patients, 1:1 3 patients

Very Low Frequencies Maintain Pain Relief from Dorsal Root Ganglion Stimulation: An Evaluation of DRG-S Frequency Tapering

Kenneth B. Chapman, MD, Tariq Yousef, MD, Kris C. Vissers, MD PhD, Noud van Helmond, MD, Michael Stanton-Hicks, MD. Very Low Frequencies Maintain Pain Relief from Dorsal Root Ganglion Stimulation: An Evaluation of DRG-S Frequency

• Tapering. Acceoted. Neuromodulation

Frequency Pulse width (µS) Intraburst Frequency Amplitude Intraburst Pulse width Recharge Total Charge/S (µC/s) Tonic SCS 50 Hz 400 µS

• 3.5 mA
• Active

10 µC/s Active Recharge Burst 40 Hz  450 Hz 6 pulses 1 Ma 250 µS Active 30 µC/s Passive Recharge Burst 40 Hz  500 Hz 5 pulses 60% threshold 1000 µS Passive 100 µC/s HF 10K Hz 30 µs

• 0.25 mA
• Active

75 µC/s

DRG 4 260 µS

• 0.6 mA
• Active

1.6 µC/s

Very Low Frequencies Maintain Pain Relief from Dorsal Root Ganglion Stimulation: An Evaluation of DRG-S Frequency Tapering

Kenneth B. Chapman, MD, Tariq Yousef, MD, Kris C. Vissers, MD PhD, Noud van Helmond, MD, Michael Stanton-Hicks, MD. Submitted Neuromodulation

Lead M Migration a and Fract cture R Rate in Dorsal Root G Ganglion Stimulation Using A Anch choring and N Non-Anchoring T Techniques: A A Multicenter Pooled Data A Analysis

Kenneth B. Chapman, MD1,2,3, Alon Y. Mogilner MD PhD4, Ajax Yang MD1,3, Abhishek Yadav MD5, Timothy Lubenow MD 6, Noud van Helmond MD1,7, Timothy Deer MD8, Jan Willem Kallewaard MD, PhD9

1The Spine & Pain Institute of New York, NY, NY, USA. 2Department of Anesthesiology, NYU Langone Medical Center, NY, NY, USA. 3Northwell Health, New

York City, NY, USA. 4 Department of Neurosurgery, NYU Langone Medical Center, NY, NY, USA. 5 Department of Anesthesiology and Perioperative Medicine, Brown University, Providence RI. 6Department of Anesthesiology, Rush University Medical Center, Chicago IL. 7 The Spine and Nerve Center of the Virginias, Charleston WV, 8 Cooper Medical School of Rowan University, Cooper University Hospital, Camden, NJ, USA. 9Rijnstate Ziekenhuis, Velp, The Netherlands.

Results

Breakdown

Study Lead locations Total leads Total Implants Migrations Lead fracture Kallewaard et al.

L2 36 18 4 3

Chapman et al.

T12-S2 52 17 3 1

Chapman unanchored (unpublished)

T11-S3 23 7 4 2

Implanter 2

T12-S1 22 10 6

Kretzschmar et al.

C4-L5 46 21 5 (24%) 2 (9%)

TOTAL

179 73 22 (30%) 8 (11%)

Kenneth Chapman, MD Chapmanken@SpinePainNY.com