1
|
Sivanesan E, North RB, Russo MA, Levy RM, Linderoth B, Hayek SM, Eldabe S, Lempka SF. A Definition of Neuromodulation and Classification of Implantable Electrical Modulation for Chronic Pain. Neuromodulation 2024; 27:1-12. [PMID: 37952135 DOI: 10.1016/j.neurom.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/24/2023] [Accepted: 10/09/2023] [Indexed: 11/14/2023]
Abstract
OBJECTIVES Neuromodulation therapies use a variety of treatment modalities (eg, electrical stimulation) to treat chronic pain. These therapies have experienced rapid growth that has coincided with escalating confusion regarding the nomenclature surrounding these neuromodulation technologies. Furthermore, studies are often published without a complete description of the effective stimulation dose, making it impossible to replicate the findings. To improve clinical care and facilitate dissemination among the public, payors, research groups, and regulatory bodies, there is a clear need for a standardization of terms. APPROACH We formed an international group of authors comprising basic scientists, anesthesiologists, neurosurgeons, and engineers with expertise in neuromodulation. Because the field of neuromodulation is extensive, we chose to focus on creating a taxonomy and standardized definitions for implantable electrical modulation of chronic pain. RESULTS We first present a consensus definition of neuromodulation. We then describe a classification scheme based on the 1) intended use (the site of modulation and its indications) and 2) physical properties (waveforms and dose) of a neuromodulation therapy. CONCLUSIONS This framework will help guide future high-quality studies of implantable neuromodulatory treatments and improve reporting of their findings. Standardization with this classification scheme and clear definitions will help physicians, researchers, payors, and patients better understand the applications of implantable electrical modulation for pain and guide informed treatment decisions.
Collapse
Affiliation(s)
- Eellan Sivanesan
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Richard B North
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Marc A Russo
- Hunter Pain Specialists, Broadmeadow, New South Wales, Australia
| | - Robert M Levy
- Neurosurgical Services, Clinical Research, Anesthesia Pain Care Consultants, Tamarac, FL, USA
| | - Bengt Linderoth
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Salim M Hayek
- Division of Pain Medicine, University Hospitals, Cleveland Medical Center, Cleveland, OH, USA
| | - Sam Eldabe
- Department of Pain Medicine, The James Cook University Hospital, Middlesbrough, UK
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
2
|
Zhuo J, Weidrick CE, Liu Y, Moffitt MA, Jansen ED, Chiel HJ, Jenkins MW. Selective Infrared Neural Inhibition Can Be Reproduced by Resistive Heating. Neuromodulation 2023; 26:1757-1771. [PMID: 36707292 PMCID: PMC10366334 DOI: 10.1016/j.neurom.2022.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/22/2022] [Accepted: 12/06/2022] [Indexed: 01/26/2023]
Abstract
OBJECTIVES Small-diameter afferent axons carry various sensory signals that are critical for vital physiological conditions but sometimes contribute to pathologies. Infrared (IR) neural inhibition (INI) can induce selective heat block of small-diameter axons, which holds potential for translational applications such as pain management. Previous research suggested that IR-heating-induced acceleration of voltage-gated potassium channel kinetics is the mechanism for INI. Therefore, we hypothesized that other heating methods, such as resistive heating (RH) in a cuff, could reproduce the selective inhibition observed in INI. MATERIALS AND METHODS We conducted ex vivo nerve-heating experiments on pleural-abdominal connective nerves of Aplysia californica using both IR and RH. We fabricated a transparent silicone nerve cuff for simultaneous IR heating, RH, and temperature measurements. Temperature elevations (ΔT) on the nerve surface were recorded for both heating modalities, which were tested over a range of power levels that cover a similar ΔT range. We recorded electrically evoked compound action potentials (CAPs) and segmented them into fast and slow subcomponents on the basis of conduction velocity differences between the large and small-diameter axonal subpopulations. We calculated the normalized inhibition strength and inhibition selectivity index on the basis of the rectified area under the curve of each subpopulation. RESULTS INI and RH showed a similar selective inhibition effect on CAP subcomponents for slow-conducting axons, confirmed by the inhibition probability vs ΔT dose-response curve based on approximately 2000 CAP measurements. The inhibition selectivity indexes of the two heating modalities were similar across six nerves. RH only required half the total electrical power required by INI to achieve a similar ΔT. SIGNIFICANCE We show that selective INI can be reproduced by other heating modalities such as RH. RH, because of its high energy efficiency and simple design, can be a good candidate for future implantable neural interface designs.
Collapse
Affiliation(s)
- Junqi Zhuo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Chloe E Weidrick
- Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - Yehe Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Michael A Moffitt
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Biophotonics Center, Vanderbilt University, Nashville, TN, USA; Department of Neurological Surgery, Vanderbilt University, Nashville, TN, USA
| | - Hillel J Chiel
- Department of Biology, Case Western Reserve University, Cleveland OH, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Michael W Jenkins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA; Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
3
|
Zannou AL, Khadka N, Bikson M. Bioheat Model of Spinal Column Heating During High-Density Spinal Cord Stimulation. Neuromodulation 2023; 26:1362-1370. [PMID: 36030146 PMCID: PMC9950282 DOI: 10.1016/j.neurom.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 07/01/2022] [Accepted: 07/09/2022] [Indexed: 11/28/2022]
Abstract
INTRODUCTION High-density (HD) spinal cord stimulation (SCS) delivers higher charge per time by increasing frequency and/or pulse duration, thus increasing stimulation energy. Previously, through phantom studies and computational modeling, we demonstrated that stimulation energy drives spinal tissue heating during kHz SCS. In this study, we predicted temperature increases in the spinal cord by HD SCS, the first step in considering the potential impact of heating on clinical outcomes. MATERIALS AND METHODS We adapted a high-resolution computer-aided design-derived spinal cord model, both with and without a lead encapsulation layer, and applied bioheat transfer finite element method multiphysics to predict temperature increases during SCS. We simulated HD SCS using a commercial SCS lead (eight contacts) with clinically relevant intensities (voltage-controlled: 0.5-7 Vrms) and electrode configuration (proximal bipolar, distal bipolar, guarded tripolar [+-+], and guarded quadripolar [+--+]). Results were compared with the conventional and 10-kHz SCS (current-controlled). RESULTS HD SCS waveform energy (reflecting charge per second) governs joule heating in the spinal tissues, increasing temperature supralinearly with stimulation root mean square. Electrode configuration and tissue properties (an encapsulation layer) influence peak tissue temperature increase-but in a manner distinct for voltage-controlled (HD SCS) compared with current-controlled (conventional/10-kHz SCS) stimulation. Therefore, depending on conditions, HD SCS could produce heating greater than that of 10-kHz SCS. For example, with an encapsulation layer, using guarded tripolar configuration (500-Hz, 250-μs pulse width, 5-Vpeak HD SCS), the peak temperature increases were 0.36 °C at the spinal cord and 1.78 °C in the epidural space. CONCLUSIONS As a direct consequence of the higher charge, HD SCS increases tissue heating; voltage-controlled stimulation introduces special dependencies on electrode configuration and lead encapsulation (reflected in impedance). If validated with an in vivo measurement as a possible mechanism of action of SCS, bioheat models of HD SCS serve as tools for programming optimization.
Collapse
Affiliation(s)
- Adantchede L Zannou
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
| | - Niranjan Khadka
- Department of Psychiatry, Division of Neuropsychiatry and Neuromodulation, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| |
Collapse
|
4
|
Liang L, Damiani A, Del Brocco M, Rogers ER, Jantz MK, Fisher LE, Gaunt RA, Capogrosso M, Lempka SF, Pirondini E. A systematic review of computational models for the design of spinal cord stimulation therapies: from neural circuits to patient-specific simulations. J Physiol 2023; 601:3103-3121. [PMID: 36409303 PMCID: PMC10259770 DOI: 10.1113/jp282884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 11/08/2022] [Indexed: 08/02/2023] Open
Abstract
Seventy years ago, Hodgkin and Huxley published the first mathematical model to describe action potential generation, laying the foundation for modern computational neuroscience. Since then, the field has evolved enormously, with studies spanning from basic neuroscience to clinical applications for neuromodulation. Computer models of neuromodulation have evolved in complexity and personalization, advancing clinical practice and novel neurostimulation therapies, such as spinal cord stimulation. Spinal cord stimulation is a therapy widely used to treat chronic pain, with rapidly expanding indications, such as restoring motor function. In general, simulations contributed dramatically to improve lead designs, stimulation configurations, waveform parameters and programming procedures and provided insight into potential mechanisms of action of electrical stimulation. Although the implementation of neural models are relentlessly increasing in number and complexity, it is reasonable to ask whether this observed increase in complexity is necessary for improved accuracy and, ultimately, for clinical efficacy. With this aim, we performed a systematic literature review and a qualitative meta-synthesis of the evolution of computational models, with a focus on complexity, personalization and the use of medical imaging to capture realistic anatomy. Our review showed that increased model complexity and personalization improved both mechanistic and translational studies. More specifically, the use of medical imaging enabled the development of patient-specific models that can help to transform clinical practice in spinal cord stimulation. Finally, we combined our results to provide clear guidelines for standardization and expansion of computational models for spinal cord stimulation.
Collapse
Affiliation(s)
- Lucy Liang
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Arianna Damiani
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matteo Del Brocco
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Evan R Rogers
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Maria K Jantz
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Lee E Fisher
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert A Gaunt
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marco Capogrosso
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Elvira Pirondini
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
5
|
Fisher LE, Lempka SF. Neurotechnology for Pain. Annu Rev Biomed Eng 2023; 25:387-412. [PMID: 37068766 DOI: 10.1146/annurev-bioeng-111022-121637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Neurotechnologies for treating pain rely on electrical stimulation of the central or peripheral nervous system to disrupt or block pain signaling and have been commercialized to treat a variety of pain conditions. While their adoption is accelerating, neurotechnologies are still frequently viewed as a last resort, after many other treatment options have been explored. We review the pain conditions commonly treated with electrical stimulation, as well as the specific neurotechnologies used for treating those conditions. We identify barriers to adoption, including a limited understanding of mechanisms of action, inconsistent efficacy across patients, and challenges related to selectivity of stimulation and off-target side effects. We describe design improvements that have recently been implemented, as well as some cutting-edge technologies that may address the limitations of existing neurotechnologies. Addressing these challenges will accelerate adoption and change neurotechnologies from last-line to first-line treatments for people living with chronic pain.
Collapse
Affiliation(s)
- Lee E Fisher
- Rehab Neural Engineering Labs, Department of Physical Medicine and Rehabilitation, and Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Scott F Lempka
- Department of Biomedical Engineering, Biointerfaces Institute, and Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan, USA;
| |
Collapse
|
6
|
Álvarez DMC, Serrano-Muñoz D, Fernández-Pérez JJ, Gómez-Soriano J, Avendaño-Coy J. Effect of percutaneous electrical stimulation with high-frequency alternating currents at 30 kHz on the sensory-motor system. Front Neurosci 2023; 17:1048986. [PMID: 36845426 PMCID: PMC9947497 DOI: 10.3389/fnins.2023.1048986] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023] Open
Abstract
Background Unmodulated high-frequency alternating currents (HFAC) are employed for producing peripheral nerves block. HFAC have been applied in humans with frequencies up to 20 kHz, whether transcutaneously, percutaneously, or via surgically-implanted electrodes. The aim of this study was to assess the effect of percutaneous HFAC, applied with ultrasound-guided needles at 30 kHz, on the sensory-motor nerve conduction of healthy volunteers. Methods A parallel, double-blind, randomized clinical trial with a placebo control was conducted. Percutaneous HFAC at 30 kHz or sham stimulation was applied via ultrasound-guided needles in 48 healthy volunteers (n = 24 in each group) for 20 min. The assessed outcome variables were pressure pain threshold (PPT), mechanical detection threshold (MDT), maximal finger flexion strength (MFFS), antidromic sensory nerve action potential (SNAP), hand temperature, and subjective sensations by the participants. The measurements were recorded pre-intervention, during the stimulation (at 15 min), immediately post-intervention (at 20 min), and 15 min after the end of treatment. Results The PPT increased in the active group compared with sham stimulation, both during the intervention [14.7%; 95% confidence interval (CI): 4.4-25.0], immediately post-intervention (16.9%; 95% CI: -7.2-26.5), and 15 min after the end of the stimulation (14.3%; 95% CI: 4.4-24.3) (p < 0.01). The proportion of participants who reported feelings of numbness and heaviness was significantly higher in the active group (46 and 50%, respectively) than in the sham group (8 and 18%, respectively) (p < 0.05). No intergroup differences were observed in the remaining outcome variables. No unexpected adverse effects derived from the electrical stimulation were reported. Conclusion Percutaneous stimulation with HFAC at 30 kHz applied to the median nerve increased the PPT and subjective perception of numbness and heaviness. Future research should evaluate its potential therapeutic effect in people with pain. Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT04884932, identifier NCT04884932.
Collapse
Affiliation(s)
- David Martín-Caro Álvarez
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | | | - Juan José Fernández-Pérez
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Julio Gómez-Soriano
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Juan Avendaño-Coy
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| |
Collapse
|
7
|
Khadka N, Bikson M. Neurocapillary-Modulation. Neuromodulation 2022; 25:1299-1311. [PMID: 33340187 PMCID: PMC8213863 DOI: 10.1111/ner.13338] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/05/2020] [Accepted: 11/23/2020] [Indexed: 02/06/2023]
Abstract
OBJECTIVES We consider two consequences of brain capillary ultrastructure in neuromodulation. First, blood-brain barrier (BBB) polarization as a consequence of current crossing between interstitial space and the blood. Second, interstitial current flow distortion around capillaries impacting neuronal stimulation. MATERIALS AND METHODS We developed computational models of BBB ultrastructure morphologies to first assess electric field amplification at the BBB (principle 1) and neuron polarization amplification by the presence of capillaries (principle 2). We adapt neuron cable theory to develop an analytical solution for maximum BBB polarization sensitivity. RESULTS Electrical current crosses between the brain parenchyma (interstitial space) and capillaries, producing BBB electric fields (EBBB) that are >400x of the average parenchyma electric field (ĒBRAIN), which in turn modulates transport across the BBB. Specifically, for a BBB space constant (λBBB) and wall thickness (dth-BBB), the analytical solution for maximal BBB electric field (EABBB) is given as: (ĒBRAIN × λBBB)/dth-BBB. Electrical current in the brain parenchyma is distorted around brain capillaries, amplifying neuronal polarization. Specifically, capillary ultrastructure produces ∼50% modulation of the ĒBRAIN over the ∼40 μm inter-capillary distance. The divergence of EBRAIN (Activating function) is thus ∼100 kV/m2 per unit ĒBRAIN. CONCLUSIONS BBB stimulation by principle 1 suggests novel therapeutic strategies such as boosting metabolic capacity or interstitial fluid clearance. Whereas the spatial profile of EBRAIN is traditionally assumed to depend only on macroscopic anatomy, principle 2 suggests a central role for local capillary ultrastructure-which impact forms of neuromodulation including deep brain stimulation (DBS), spinal cord stimulation (SCS), transcranial magnetic stimulation (TMS), electroconvulsive therapy (ECT), and transcranial electrical stimulation (tES)/transcranial direct current stimulation (tDCS).
Collapse
Affiliation(s)
- Niranjan Khadka
- Department of Psychiatry, Laboratory for Neuropsychiatry and Neuromodulation, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA.
| |
Collapse
|
8
|
Kim T, Kadji H, Whalen AJ, Ashourvan A, Freeman E, Fried SI, Tadigadapa S, Schiff SJ. Thermal effects on neurons during stimulation of the brain. J Neural Eng 2022; 19:056029. [PMID: 36126646 PMCID: PMC9855718 DOI: 10.1088/1741-2552/ac9339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 01/25/2023]
Abstract
All electric and magnetic stimulation of the brain deposits thermal energy in the brain. This occurs through either Joule heating of the conductors carrying current through electrodes and magnetic coils, or through dissipation of energy in the conductive brain.Objective.Although electrical interaction with brain tissue is inseparable from thermal effects when electrodes are used, magnetic induction enables us to separate Joule heating from induction effects by contrasting AC and DC driving of magnetic coils using the same energy deposition within the conductors. Since mammalian cortical neurons have no known sensitivity to static magnetic fields, and if there is no evidence of effect on spike timing to oscillating magnetic fields, we can presume that the induced electrical currents within the brain are below the molecular shot noise where any interaction with tissue is purely thermal.Approach.In this study, we examined a range of frequencies produced from micromagnetic coils operating below the molecular shot noise threshold for electrical interaction with single neurons.Main results.We found that small temperature increases and decreases of 1∘C caused consistent transient suppression and excitation of neurons during temperature change. Numerical modeling of the biophysics demonstrated that the Na-K pump, and to a lesser extent the Nernst potential, could account for these transient effects. Such effects are dependent upon compartmental ion fluxes and the rate of temperature change.Significance.A new bifurcation is described in the model dynamics that accounts for the transient suppression and excitation; in addition, we note the remarkable similarity of this bifurcation's rate dependency with other thermal rate-dependent tipping points in planetary warming dynamics. These experimental and theoretical findings demonstrate that stimulation of the brain must take into account small thermal effects that are ubiquitously present in electrical and magnetic stimulation. More sophisticated models of electrical current interaction with neurons combined with thermal effects will lead to more accurate modulation of neuronal activity.
Collapse
Affiliation(s)
- TaeKen Kim
- Department of Physics, The Pennsylvania State University, University Park, PA, United States of America
| | - Herve Kadji
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
- Department of Radiation Oncology, Hackensack Meridian Health Mountainside Medical Center, Montclair, NJ, United States of America
| | - Andrew J Whalen
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Department of Neurosurgery, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States of America
| | - Arian Ashourvan
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
| | - Eugene Freeman
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Honeywell International Aerospace Advanced Technology, Plymouth, MN, United States of America
| | - Shelley I Fried
- Department of Neurosurgery, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States of America
- Boston VA Healthcare System, Boston 02130, United States of America
| | - Srinivas Tadigadapa
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, United States of America
| | - Steven J Schiff
- Department of Physics, The Pennsylvania State University, University Park, PA, United States of America
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
- Department of Neurosurgery, Penn State College of Medicine, Hershey, PA 17033, United States of America
- Department of Neurosurgery, Yale University, 333 Cedar Street, TMP 410, New Haven, CT 06510, United States of America
| |
Collapse
|
9
|
Baker TS, Zannou AL, Cruz D, Khadka N, Kellner C, Tyc R, Bikson M, Costa A. Development and Clinical Validation of a Finite Element Method Model Mapping Focal Intracranial Cooling. IEEE Trans Neural Syst Rehabil Eng 2022; 30:2168-2174. [PMID: 35316187 PMCID: PMC9533256 DOI: 10.1109/tnsre.2022.3161085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Therapeutic hypothermia (TH) is a common and effective technique to reduce inflammation and induce neuroprotection across a variety of diseases. Focal TH of the brain can avoid the side effects of systemic cooling. The degree and extent of focal TH are a function of cooling probe design and local brain thermoregulation processes. To refine focal TH probe design, with application-specific optimization, we develop precise computational models of brain thermodynamics under intense local cooling. Here, we present a novel multiphysics in silico model that can accurately predict brain response to focal cooling. The model was parameterized from previously described values of metabolic activity, thermal conductivity, and temperature-dependent cerebral perfusion. The model was validated experimentally using data from clinical cases where local cooling was induced intracranially and brain temperatures monitored in real-time with MR thermometry. The validated model was then used to identify optimal design probe parameters to maximize volumetric TH, including considering three stratifications of cooling (mild, moderate, and profound) to produce Volume of Tissue Cooled (VOTC) maps. We report cooling radius increases in a nearly linear fashion with probe length and decreasing probe surface temperature.
Collapse
|
10
|
Dmochowski JP, Khadka N, Cardoso L, Meneses E, Lee K, Kim S, Jin Y, Bikson M. Computational Modeling of Deep Tissue Heating by an Automatic Thermal Massage Bed: Predicting the Effects on Circulation. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:925554. [PMID: 35774152 PMCID: PMC9238293 DOI: 10.3389/fmedt.2022.925554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022] Open
Abstract
Automatic thermal and mechanical massage beds support self-managed treatment, including reduction of pain and stress, enhanced circulation, and improved mobility. As the devices become more sophisticated (increasing the degrees of freedom), it is essential to identify the settings that best target the desired tissue. To that end, we developed an MRI-derived model of the lower back and simulated the physiological effects of a commercial thermal-mechanical massage bed. Here we specifically estimated the tissue temperature and increased circulation under steady-state conditions for typical thermal actuator settings (i.e., 45–65°C). Energy transfer across nine tissues was simulated with finite element modeling (FEM) and the resulting heating was coupled to blood flow with an empirically-guided model of temperature-dependent circulation. Our findings indicate that thermal massage increases tissue temperature by 3–8°C and 1–3°C at depths of 2 and 3 cm, respectively. Importantly, due to the rapid (non-linear) increase of circulation with local temperature, this is expected to increase blood flow four-fold (4x) at depths occupied by deep tissue and muscle. These predictions are consistent with prior clinical observations of therapeutic benefits derived from spinal thermal massage.
Collapse
Affiliation(s)
- Jacek P. Dmochowski
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
- *Correspondence: Jacek P. Dmochowski
| | - Niranjan Khadka
- Division of Neuropsychiatry and Neuromodulation, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Luis Cardoso
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
| | - Edson Meneses
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
| | - Kiwon Lee
- Clinical Research Institute, Ceragem Clinical Inc., Seoul, South Korea
| | - Sungjin Kim
- Clinical Research Institute, Ceragem Clinical Inc., Seoul, South Korea
| | - Youngsoo Jin
- Clinical Research Institute, Ceragem Clinical Inc., Seoul, South Korea
- Asan Medical Center, Seoul, South Korea
| | - Marom Bikson
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
| |
Collapse
|
11
|
|
12
|
Álvarez DMC, Serrano-Muñoz D, Fernández-Pérez JJ, Gómez-Soriano J, Avendaño-Coy J. Effect of Percutaneous Electric Stimulation with High-Frequency Alternating Currents on the Sensory-Motor System of Healthy Volunteers: A Double-Blind Randomized Controlled Study. J Clin Med 2022; 11:jcm11071832. [PMID: 35407438 PMCID: PMC8999650 DOI: 10.3390/jcm11071832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/17/2022] [Accepted: 03/24/2022] [Indexed: 02/05/2023] Open
Abstract
Former studies investigated the application of high-frequency alternating currents (HFAC) in humans for blocking the peripheral nervous system. The present trial aims to assess the effect of HFAC on the motor response, somatosensory thresholds, and peripheral nerve conduction when applied percutaneously using frequencies of 10 kHz and 20 kHz in healthy volunteers. A parallel, placebo-controlled, double-blind, randomized clinical trial was conducted. Ultrasound-guided HFAC at 10 kHz and 20 kHz and sham stimulation were delivered to the median nerve of 60 healthy volunteers for 20 min. The main assessed variables were the maximum isometric flexion strength (MFFS) of the index finger, myotonometry, pressure pain threshold (PPT), mechanical detection threshold (MDT), and sensory nerve action potential (SNAP). A decrease in the MFFS is observed immediately postintervention compared to baseline, both in the 10 kHz group (−8.5%; 95% CI −14.9 to −2.1) and the 20 kHz group (−12.0%; 95% CI −18.3 to −5.6). The between-group comparison of changes in MFFS show a greater reduction of −10.8% (95% CI −19.8 to −1.8) immediately postintervention in the 20 kHz compared to the sham stimulation group. The percutaneous stimulation applying 20 kHz HFAC to the median nerve produces a reversible postintervention reduction in strength with no adverse effects.
Collapse
|
13
|
Rigoard P, Roulaud M, Goudman L, Adjali N, Ounajim A, Voirin J, Perruchoud C, Bouche B, Page P, Guillevin R, Naudin M, Simoneau M, Lorgeoux B, Baron S, Nivole K, Many M, Maitre I, Rigoard R, David R, Moens M, Billot M. Comparison of Spinal Cord Stimulation vs. Dorsal Root Ganglion Stimulation vs. Association of Both in Patients with Refractory Chronic Back and/or Lower Limb Neuropathic Pain: An International, Prospective, Randomized, Double-Blinded, Crossover Trial (BOOST-DRG Study). MEDICINA (KAUNAS, LITHUANIA) 2021; 58:7. [PMID: 35056316 PMCID: PMC8780129 DOI: 10.3390/medicina58010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/01/2021] [Accepted: 12/15/2021] [Indexed: 12/25/2022]
Abstract
While spinal cord stimulation (SCS) is a well-established therapy to address refractory persistent spinal pain syndrome after spinal surgery (PSPS-T2), its lack of spatial selectivity and reported discomfort due to positional effects can be considered as significant limitations. As alternatives, new waveforms, such as burst stimulation and different spatial neural targets, such as dorsal root ganglion stimulation (DRGS), have shown promising results. Comparisons between DRGS and standard SCS, or their combination, have never been studied on the same patients. "BOOST DRG" is the first prospective, randomized, double-blinded, crossover study to compare SCS vs. DRGS vs. SCS+DRGS. Sixty-six PSPS-T2 patients will be recruited internationally in three centers. Before crossing over, patients will receive each stimulation modality for 1 month, using tonic conventional stimulation. After 3 months, stimulation will consist in switching to burst for 1 month, and patients will choose which modality/waveform they receive and will then be reassessed at 6 and 12 months. In addition to our primary outcome based on pain rating, this study is designed to assess quality of life, functional disability, psychological distress, pain surface coverage, global impression of change, medication quantification, adverse events, brain functional imaging and electroencephalography, with the objective being to provide a multidimensional insight based on composite pain assessment.
Collapse
Affiliation(s)
- Philippe Rigoard
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
- Pprime Institute UPR 3346, CNRS, ISAE-ENSMA, University of Poitiers, 86360 Chasseneuil-du-Poitou, France
| | - Manuel Roulaud
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Lisa Goudman
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium; (L.G.); (M.M.)
- STUMULUS Research Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Nihel Adjali
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Amine Ounajim
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Jimmy Voirin
- Department of Neurosurgery, Hopitaux Civils de Colmar, 68000 Colmar, France;
| | - Christophe Perruchoud
- Service of Anesthesiology and Pain Centre, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland;
| | - Bénédicte Bouche
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
| | - Philippe Page
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
| | - Rémy Guillevin
- Department of Radiology, Poitiers University Hospital, 86021 Poitiers, France; (R.G.); (M.N.)
- UMR CNRS 7348, DACTIM-MIS/LMA Laboratory, University of Poitiers, 86000 Poitiers, France
| | - Mathieu Naudin
- Department of Radiology, Poitiers University Hospital, 86021 Poitiers, France; (R.G.); (M.N.)
- UMR CNRS 7348, DACTIM-MIS/LMA Laboratory, University of Poitiers, 86000 Poitiers, France
| | - Martin Simoneau
- Department of Kinesiology, Faculty of Medicine, Laval University, Quebec, QC G1V 0A6, Canada;
- Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), Quebec, QC G1M 2S8, Canada
| | - Bertille Lorgeoux
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Sandrine Baron
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Kevin Nivole
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Mathilde Many
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Iona Maitre
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Raphaël Rigoard
- CEA Cadarache, Département de Support Technique et Gestion, Service des Technologies de l’Information et de la Communication, 13108 Saint-Paul-Lez-Durance, France;
| | - Romain David
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Physical and Rehabilitation Medicine, Poitiers University Hospital, University of Poitiers, 86021 Poitiers, France
| | - Maarten Moens
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium; (L.G.); (M.M.)
- STUMULUS Research Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Maxime Billot
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| |
Collapse
|
14
|
Malinowski MN, Chopra PR, Tieppo Francio V, Budwany R, Deer TR. A narrative review and future considerations of spinal cord stimulation, dorsal root ganglion stimulation and peripheral nerve stimulation. Curr Opin Anaesthesiol 2021; 34:774-780. [PMID: 34608057 DOI: 10.1097/aco.0000000000001072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW In recent years, neuromodulation has experienced a renaissance. Novel waveforms and anatomic targets show potential improvements in therapy that may signify substantial benefits. New innovations in peripheral nerve stimulation and dorsal root ganglion stimulation have shown prospective evidence and sustainability of results. Sub-perception physiologic bursting, high-frequency stimulation and feedback loop mechanisms provide significant benefits over traditional tonic spinal cords stimulation (SCS) in peer reviewed investigations. We reviewed the themes associated with novel technology in the context of historical stalwart publications. RECENT FINDINGS New innovations have led to better nerve targeting, improvements in disease-based treatment, and opioid alternatives for those in chronic pain. In addition, new neural targets from both structural and cellular perspectives have changed the field of Neurostimulation. SUMMARY For many years, tonic SCS was representative of neuromodulation, but as this review examines, the progression of the field in the past decade has reshaped patient options.
Collapse
Affiliation(s)
- Mark N Malinowski
- OhioHealth Grant Medical Center, Ohio University Heritage COM, Columbus, Ohio
| | | | - Vinicius Tieppo Francio
- The University of Kansas Medical Center, Department of Rehabilitative Medicine, Kansas City, Kansas
| | - Ryan Budwany
- Center for Integrative Pain Management, West Virginia University School of Medicine, Morgantown
| | - Timothy Ray Deer
- The Spine and Nerve Center of The Virginias
- Anesthesiology and Pain Medicine, WVU School of Medicine
- American Society of Pain and Neuroscience, Charleston, West Virginia, USA
| |
Collapse
|
15
|
Zannou AL, Khadka N, FallahRad M, Truong DQ, Kopell BH, Bikson M. Tissue Temperature Increases by a 10 kHz Spinal Cord Stimulation System: Phantom and Bioheat Model. Neuromodulation 2021; 24:1327-1335. [PMID: 31225695 PMCID: PMC6925358 DOI: 10.1111/ner.12980] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 05/10/2019] [Accepted: 05/11/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVE A recently introduced Spinal Cord Stimulation (SCS) system operates at 10 kHz, faster than conventional SCS systems, resulting in significantly more power delivered to tissues. Using a SCS heat phantom and bioheat multi-physics model, we characterized tissue temperature increases by this 10 kHz system. We also evaluated its Implanted Pulse Generator (IPG) output compliance and the role of impedance in temperature increases. MATERIALS AND METHODS The 10 kHz SCS system output was characterized under resistive loads (1-10 KΩ). Separately, fiber optic temperature probes quantified temperature increases (ΔTs) around the SCS lead in specially developed heat phantoms. The role of stimulation Level (1-7; ideal pulse peak-to-peak of 1-7mA) was considered, specifically in the context of stimulation current Root Mean Square (RMS). Data from the heat phantom were verified with the SCS heat-transfer models. A custom high-bandwidth stimulator provided 10 kHz pulses and sinusoidal stimulation for control experiments. RESULTS The 10 kHz SCS system delivers 10 kHz biphasic pulses (30-20-30 μs). Voltage compliance was 15.6V. Even below voltage compliance, IPG bandwidth attenuated pulse waveform, limiting applied RMS. Temperature increased supralinearly with stimulation Level in a manner predicted by applied RMS. ΔT increases with Level and impedance until stimulator compliance was reached. Therefore, IPG bandwidth and compliance dampen peak heating. Nonetheless, temperature increases predicted by bioheat multi-physic models (ΔT = 0.64°C and 1.42°C respectively at Level 4 and 7 at the cervical segment; ΔT = 0.68°C and 1.72°C respectively at Level 4 and 7 at the thoracic spinal cord)-within ranges previously reported to effect neurophysiology. CONCLUSIONS Heating of spinal tissues by this 10 kHz SCS system theoretically increases quickly with stimulation level and load impedance, while dampened by IPG pulse bandwidth and voltage compliance limitations. If validated in vivo as a mechanism of kHz SCS, bioheat models informed by IPG limitations allow prediction and optimization of temperature changes.
Collapse
Affiliation(s)
- Adantchede L Zannou
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| | - Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| | - Mohamad FallahRad
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| | - Dennis Q. Truong
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| | - Brian H. Kopell
- Department of Neurosurgery, Neurology, Psychiatry and Neuroscience, The Icahn School of Medicine, Mount Sinai, New York, NY
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| |
Collapse
|
16
|
Chakravarthy K, Reddy R, Al-Kaisy A, Yearwood T, Grider J. A Call to Action Toward Optimizing the Electrical Dose Received by Neural Targets in Spinal Cord Stimulation Therapy for Neuropathic Pain. J Pain Res 2021; 14:2767-2776. [PMID: 34522135 PMCID: PMC8434932 DOI: 10.2147/jpr.s323372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/16/2021] [Indexed: 12/20/2022] Open
Abstract
Spinal cord stimulation has seen unprecedented growth in new technology in the 50 years since the first subdural implant. As we continue to grow our understanding of spinal cord stimulation and relevant mechanisms of action, novel questions arise as to electrical dosing optimization. Programming adjustment — dose titration — is often a process of trial and error that can be time-consuming and frustrating for both patient and clinician. In this report, we review the current preclinical and clinical knowledge base in order to provide insights that may be helpful in developing more rational approaches to spinal cord stimulation dosing. We also provide key conclusions that may help in directing future research into electrical dosing, given the advent of newer waveforms outside traditional programming parameters.
Collapse
Affiliation(s)
- Krishnan Chakravarthy
- Department of Anesthesiology and Pain Medicine, University of California San Diego Health Sciences, San Diego, CA, USA.,VA San Diego Healthcare System, San Diego, Ca, USA
| | - Rajiv Reddy
- Department of Anesthesiology and Pain Medicine, University of California San Diego Health Sciences, San Diego, CA, USA
| | - Adnan Al-Kaisy
- Pain Management and Neuromodulation Centre at Guy's and St. Thomas' NHS Trust, London, UK
| | - Thomas Yearwood
- Pain Management and Neuromodulation Centre at Guy's and St. Thomas' NHS Trust, London, UK
| | - Jay Grider
- Division of Pain Medicine, Department of Anesthesiology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| |
Collapse
|
17
|
Electrochemical Skin Conductance Alterations during Spinal Cord Stimulation: An Experimental Study. J Clin Med 2021; 10:jcm10163565. [PMID: 34441864 PMCID: PMC8397194 DOI: 10.3390/jcm10163565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 11/17/2022] Open
Abstract
Despite the well-known clinical effects of spinal cord stimulation (SCS), the mechanisms of action have not yet been fully unraveled. The primary aim of this study was to measure whether electrochemical skin conductance, as a measure of peripheral sympathetic autonomic function, is altered by SCS. A second aim was to compare skin conductance levels of patients with failed back surgery syndrome (FBSS) with age- and sex-matched healthy controls. Twenty-three patients with FBSS treated with SCS participated in this study. Sudomotor function was measured with the SudoscanTM instrument on the hands and feet during SCS on and off states. Difference scores in skin conductance between patients and age- and sex-matched healthy controls were calculated. Normal sudomotor function at the painful lower limb was revealed for 61% of the patients when SCS was activated. Skin conductance levels were not altered between on and off states of SCS. Differences in scores between patients and healthy controls were significantly different from zero. This study showed that SCS does not influencing the sympathetic nervous system in patients with FBSS, as measured by skin conductance levels. Moreover, it suggested that there is no normalization of the functioning of the sympathetic nervous system, despite the effectiveness of SCS to reduce pain intensity.
Collapse
|
18
|
Tieppo Francio V, Polston KF, Murphy MT, Hagedorn JM, Sayed D. Management of Chronic and Neuropathic Pain with 10 kHz Spinal Cord Stimulation Technology: Summary of Findings from Preclinical and Clinical Studies. Biomedicines 2021; 9:biomedicines9060644. [PMID: 34200097 PMCID: PMC8229652 DOI: 10.3390/biomedicines9060644] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/12/2021] [Accepted: 06/01/2021] [Indexed: 12/12/2022] Open
Abstract
Since the inception of spinal cord stimulation (SCS) in 1967, the technology has evolved dramatically with important advancements in waveforms and frequencies. One such advancement is Nevro’s Senza® SCS System for HF10, which received Food and Drug and Administration (FDA) approval in 2015. Low-frequency SCS works by activating large-diameter Aβ fibers in the lateral discriminatory pathway (pain location, intensity, quality) at the dorsal column (DC), creating paresthesia-based stimulation at lower-frequencies (30–120 Hz), high-amplitude (3.5–8.5 mA), and longer-duration/pulse-width (100–500 μs). In contrast, high-frequency 10 kHz SCS works with a proposed different mechanism of action that is paresthesia-free with programming at a frequency of 10,000 Hz, low amplitude (1–5 mA), and short-duration/pulse-width (30 μS). This stimulation pattern selectively activates inhibitory interneurons in the dorsal horn (DH) at low stimulation intensities, which do not activate the dorsal column fibers. This ostensibly leads to suppression of hyperexcitable wide dynamic range neurons (WDR), which are sensitized and hyperactive in chronic pain states. It has also been reported to act on the medial pathway (drives attention and pain perception), in addition to the lateral pathways. Other theories include a reversible depolarization blockade, desynchronization of neural signals, membrane integration, glial–neuronal interaction, and induced temporal summation. The body of clinical evidence regarding 10 kHz SCS treatment for chronic back pain and neuropathic pain continues to grow. There is high-quality evidence supporting its use in patients with persistent back and radicular pain, particularly after spinal surgery. High-frequency 10 kHz SCS studies have demonstrated robust statistically and clinically significant superiority in pain control, compared to paresthesia-based SCS, supported by level I clinical evidence. Yet, as the field continues to grow with the technological advancements of multiple waveforms and programming stimulation algorithms, we encourage further research to focus on the ability to modulate pain with precision and efficacy, as the field of neuromodulation continues to adapt to the modern healthcare era.
Collapse
Affiliation(s)
- Vinicius Tieppo Francio
- Department of Rehabilitation Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Keith F Polston
- Department of Rehabilitation Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Micheal T Murphy
- Department of Rehabilitation Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jonathan M Hagedorn
- Department of Anesthesiology and Perioperative Medicine, Division of Pain Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Dawood Sayed
- Department of Anesthesiology, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| |
Collapse
|
19
|
Neudorfer C, Chow CT, Boutet A, Loh A, Germann J, Elias GJ, Hutchison WD, Lozano AM. Kilohertz-frequency stimulation of the nervous system: A review of underlying mechanisms. Brain Stimul 2021; 14:513-530. [PMID: 33757930 DOI: 10.1016/j.brs.2021.03.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Electrical stimulation in the kilohertz-frequency range has gained interest in the field of neuroscience. The mechanisms underlying stimulation in this frequency range, however, are poorly characterized to date. OBJECTIVE/HYPOTHESIS To summarize the manifold biological effects elicited by kilohertz-frequency stimulation in the context of the currently existing literature and provide a mechanistic framework for the neural responses observed in this frequency range. METHODS A comprehensive search of the peer-reviewed literature was conducted across electronic databases. Relevant computational, clinical, and mechanistic studies were selected for review. RESULTS The effects of kilohertz-frequency stimulation on neural tissue are diverse and yield effects that are distinct from conventional stimulation. Broadly, these can be divided into 1) subthreshold, 2) suprathreshold, 3) synaptic and 4) thermal effects. While facilitation is the dominating mechanism at the subthreshold level, desynchronization, spike-rate adaptation, conduction block, and non-monotonic activation can be observed during suprathreshold kilohertz-frequency stimulation. At the synaptic level, kilohertz-frequency stimulation has been associated with the transient depletion of the available neurotransmitter pool - also known as synaptic fatigue. Finally, thermal effects associated with extrinsic (environmental) and intrinsic (associated with kilohertz-frequency stimulation) temperature changes have been suggested to alter the neural response to stimulation paradigms. CONCLUSION The diverse spectrum of neural responses to stimulation in the kilohertz-frequency range is distinct from that associated with conventional stimulation. This offers the potential for new therapeutic avenues across stimulation modalities. However, stimulation in the kilohertz-frequency range is associated with distinct challenges and caveats that need to be considered in experimental paradigms.
Collapse
Affiliation(s)
- Clemens Neudorfer
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - Clement T Chow
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - Alexandre Boutet
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - Aaron Loh
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - Jürgen Germann
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - Gavin Jb Elias
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada
| | - William D Hutchison
- Krembil Research Institute, University of Toronto, Ontario, Canada; Department of Physiology, Toronto Western Hospital and University of Toronto, Ontario, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada; Krembil Research Institute, University of Toronto, Ontario, Canada.
| |
Collapse
|
20
|
Limited Sensitivity of Hippocampal Synaptic Function or Network Oscillations to Unmodulated Kilohertz Electric Fields. eNeuro 2020; 7:ENEURO.0368-20.2020. [PMID: 33328248 PMCID: PMC7773889 DOI: 10.1523/eneuro.0368-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 11/21/2022] Open
Abstract
Understanding the cellular mechanisms of kilohertz (kHz) electrical stimulation is of broad interest in neuromodulation including forms of transcranial electrical stimulation, interferential stimulation, and high-rate spinal cord stimulation (SCS). Yet, the well-established low-pass filtering by neuronal membranes suggests minimal neuronal polarization in respond to charge-balanced kHz stimulation. The hippocampal brain slice model is among the most studied systems in neuroscience and exhaustively characterized in screening the effects of electrical stimulation. High-frequency electric fields of varied amplitudes (1–150 V/m), waveforms (sinusoidal, symmetrical pule, asymmetrical pulse) and frequencies (1 and10 kHz) were tested. Changes in single or paired-pulse field EPSPs (fEPSP) in CA1 were measured in response to radial-directed and tangential-directed electric fields, with brief (30 s) or long (30 min) application times. The effects of kHz stimulation on ongoing endogenous network activity were tested in carbachol-induced γ oscillation of CA3a and CA3c. Across 23 conditions evaluated, no significant changes in fEPSP were resolved, while responses were detected for within-slice control direct current (DC) fields; 1-kHz sinusoidal and pulse stimulation (≥60 V/m), but not 10 kHz, induced changes in oscillating neuronal network. We thus report no responses to low-amplitude 1-kHz or any 10-kHz fields, suggesting that any brain sensitivity to these fields is via yet to be-determined mechanism(s) of action which were not identified in our experimental preparation.
Collapse
|
21
|
Jotwani R, Abd-Elsayed A, Villegas K, Shakil A, Gulati A, Sayed D, Lam C, Mehta N. Failure of SCS MR-Conditional Modes Due to High Impedance: A Review of Literature and Case Series. Pain Ther 2020; 10:729-737. [PMID: 33219927 PMCID: PMC8119585 DOI: 10.1007/s40122-020-00219-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/13/2020] [Indexed: 12/31/2022] Open
Abstract
Introduction Magnetic resonance imaging (MRI) conditional modes are a novel feature for certain Food and Drug Administration (FDA)-approved spinal cord stimulation (SCS) devices. However, there is a paucity of literature around the limitation of MRI-conditional modes (“MRI safe”), specifically in clinical scenarios where urgent MRIs may be needed. One such limitation is load impedance, referring to the circuit’s resistance to the current being generated by the system. High impedance can limit the MRI-conditional mode capability, presenting potential harm to a patient undergoing an MRI or make an MRI unable to be completed. Methods Three cases were identified, and informed consent was obtained. All information was obtained via retrospective chart review. Results In this case series of three patients where MRI-conditional SCS systems were unable to be placed in “MRI safe” settings, preventing timely MRI study completion in the setting of high impedance, all three were required to undergo alternative imaging including CT scans, and two patients ultimately had the system explanted and one chose to be re-implanted after completion of scans. Conclusion This case series highlights the need for further investigation of impedance in SCS systems and potential limitations for future MRI usage. The review of literature of impedance in SCS shows both device- and physiologic-related etiologies for changes in impedance that warrant consideration by the implanting physician.
Collapse
Affiliation(s)
- Rohan Jotwani
- Anesthesiology, NewYork-Presbyterian/Weill Cornell Medical Center, New York, NY, USA
| | - Alaa Abd-Elsayed
- Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Kristine Villegas
- Anesthesiology, NewYork-Presbyterian/Weill Cornell Medical Center, New York, NY, USA
| | - Ahmed Shakil
- Anesthesiology, NewYork-Presbyterian/Weill Cornell Medical Center, New York, NY, USA
| | - Amitabh Gulati
- Anesthesia and Critical Care, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Dawood Sayed
- Anesthesiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Christopher Lam
- Anesthesiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Neel Mehta
- Anesthesiology, NewYork-Presbyterian/Weill Cornell Medical Center, New York, NY, USA
| |
Collapse
|
22
|
Esmaeilpour Z, Kronberg G, Reato D, Parra LC, Bikson M. Temporal interference stimulation targets deep brain regions by modulating neural oscillations. Brain Stimul 2020; 14:55-65. [PMID: 33186778 PMCID: PMC9382891 DOI: 10.1016/j.brs.2020.11.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 11/06/2020] [Accepted: 11/07/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Temporal interference (TI) stimulation of the brain generates amplitude-modulated electric fields oscillating in the kHz range with the goal of non-invasive targeted deep brain stimulation. Yet, the current intensities required in human (sensitivity) to modulate deep brain activity and if superficial brain region are spared (selectivity) at these intensities remains unclear. OBJECTIVE We developed an experimentally constrained theory for TI sensitivity to kHz electric field given the attenuation by membrane low-pass filtering property, and for TI selectivity to deep structures given the distribution of modulated and unmodulated electric fields in brain. METHODS The electric field threshold to modulate carbachol-induced gamma oscillations in rat hippocampal slices was determined for unmodulated 0.05-2 kHz sine waveforms, and 5 Hz amplitude-modulated waveforms with 0.1-2 kHz carrier frequencies. The neuronal effects are replicated with a computational network model to explore the underlying mechanisms, and then coupled to a validated current-flow model of the human head. RESULTS Amplitude-modulated electric fields are stronger in deep brain regions, while unmodulated electric fields are maximal at the cortical regions. Both experiment and model confirmed the hypothesis that spatial selectivity of temporal interference stimulation depends on the phasic modulation of neural oscillations only in deep brain regions. Adaptation mechanism (e.g. GABAb) enhanced sensitivity to amplitude modulated waveform in contrast to unmodulated kHz and produced selectivity in modulating gamma oscillation (i.e. Higher gamma modulation in amplitude modulated vs unmodulated kHz stimulation). Selection of carrier frequency strongly affected sensitivity to amplitude modulation stimulation. Amplitude modulated stimulation with 100 Hz carrier frequency required ∼5 V/m (corresponding to ∼13 mA at the scalp surface), whereas, 1 kHz carrier frequency ∼60 V/m (∼160 mA) and 2 kHz carrier frequency ∼80 V/m (∼220 mA) to significantly modulate gamma oscillation. Sensitivity is increased (scalp current required decreased) for theoretical neuronal membranes with faster time constants. CONCLUSION The TI sensitivity (current required at the scalp) depends on the neuronal membrane time-constant (e.g. axons) approaching the kHz carrier frequency. TI selectivity is governed by network adaption (e.g. GABAb) that is faster than the amplitude-modulation frequency. Thus, we show neuronal and network oscillations time-constants determine the scalp current required and the selectivity achievable with TI in humans.
Collapse
Affiliation(s)
- Zeinab Esmaeilpour
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA.
| | - Greg Kronberg
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA
| | - Davide Reato
- Champalimaud Centre for the Unknown, Neuroscience Program, Lisbon, Portugal
| | - Lucas C Parra
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA
| |
Collapse
|
23
|
Malinowski MN, Jain S, Jassal N, Deer T. Spinal cord stimulation for the treatment of neuropathic pain: expert opinion and 5-year outlook. Expert Rev Med Devices 2020; 17:1293-1302. [PMID: 32715786 DOI: 10.1080/17434440.2020.1801411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Spinal cord stimulation (SCS) is an effective treatment for chronic, intractable neuropathic pain. There have been relatively few high-level studies that suggest its unequivocal use. The decay of stimulation efficacy over time have opened opportunity for the entrance of new pulse trains and waveforms. AREAS COVERED In this state-of-the-art review, we focused on many of the major studies published in the last 10 years that were considered level one evidence. A retrospective narrative approach was taken to conceptualize foundation studies as they pertain to current evidence. A special focus was taken on reported safety outcomes in comparison to foundation studies especially as they pertain to our 5-year outlook on the use of spinal cord stimulation. EXPERT OPINION We find there are still significant limitations in the body of reviewed evidence and suggest that long-term data beyond 24 months are lacking in the literature. In addition, adverse event rates, device explantation rates and the sham effect looms as important concepts to address in the future in spite of the existing novel stimulation paradigms.
Collapse
Affiliation(s)
| | - Sameer Jain
- Pain Treatment Centers of America , Little Rock, AR, USA
| | - Navdeep Jassal
- School of Medicine - Neurology & Pain, University of South Florida , Wesley Chapel, FL, USA
| | - Timothy Deer
- Spine and Nerve Center of the Virginias , Charleston, WV, USA
| |
Collapse
|
24
|
Khadka N, Liu X, Zander H, Swami J, Rogers E, Lempka SF, Bikson M. Realistic anatomically detailed open-source spinal cord stimulation (RADO-SCS) model. J Neural Eng 2020; 17:026033. [DOI: 10.1088/1741-2552/ab8344] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
25
|
Khadka N, Harmsen IE, Lozano AM, Bikson M. Bio-Heat Model of Kilohertz-Frequency Deep Brain Stimulation Increases Brain Tissue Temperature. Neuromodulation 2020; 23:489-495. [PMID: 32058634 DOI: 10.1111/ner.13120] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/18/2019] [Accepted: 01/14/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Early clinical trials suggest that deep brain stimulation at kilohertz frequencies (10 kHz-DBS) may be effective in improving motor symptoms in patients with movement disorders. The 10 kHz-DBS can deliver significantly more power in tissue compared to conventional frequency DBS, reflecting increased pulse compression (duty cycle). We hypothesize that 10 kHz-DBS modulates neuronal function through moderate local tissue heating, analogous to kilohertz spinal cord stimulation (10 kHz-SCS). To establish the role of tissue heating in 10 kHz-DBS (30 μs, 10 kHz, at intensities of 3-7 mApeak ), a decisive first step is to characterize the range of temperature changes during clinical kHz-DBS protocols. MATERIALS AND METHODS We developed a high-resolution magnetic resonance imaging-derived DBS model incorporating joule-heat coupled bio-heat multi-physics to establish the role of tissue heating. Volume of tissue activated (VTA) under assumptions of activating function (for 130 Hz) or heating (for 10 kHz) based neuromodulation are contrasted. RESULTS DBS waveform power (waveform RMS) determined joule heating at the deep brain tissues. Peak heating was supralinearly dependent on stimulation RMS. The 10 kHz-DBS stimulation with 2.3 to 5.4 mARMS (corresponding to 3 to 7 mApeak ) produced 0.10 to 1.38°C heating at the subthalamic nucleus (STN) target under standard tissue parameters. Maximum temperature increases were predicted inside the electrode encapsulation layer (enCAP) with 2.3 to 5.4 mARMS producing 0.13 to 1.87°C under standard tissue parameters. Tissue parameter analysis predicted STN heating was especially sensitive (ranging from 0.44 to 1.35°C at 3.8 mARMS ) to decreasing enCAP electrical conductivity and decreasing STN thermal conductivity. CONCLUSIONS Subject to validation with in vivo measurements, neuromodulation through a heating mechanism of action by 10 kHz-DBS can indicate novel therapeutic pathways and strategies for dose optimization.
Collapse
Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Irene E Harmsen
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| |
Collapse
|
26
|
Khadka N, Bikson M. Response to the Letter to the Editor by Caraway et al. on "Tissue Temperature Increases by a 10 kHz Spinal Cord Stimulation System: Phantom and Bioheat Model". Neuromodulation 2020; 22:988. [PMID: 31846544 DOI: 10.1111/ner.13079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA
| |
Collapse
|
27
|
Caraway DL, Bradley K. Response to: "Tissue Temperature Increases by a 10 kHz Spinal Cord Stimulation System: Phantom and Bioheat Model". Neuromodulation 2020; 22:986-987. [PMID: 31846545 DOI: 10.1111/ner.13078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
28
|
Horváth ÁC, Borbély S, Boros ÖC, Komáromi L, Koppa P, Barthó P, Fekete Z. Infrared neural stimulation and inhibition using an implantable silicon photonic microdevice. MICROSYSTEMS & NANOENGINEERING 2020; 6:44. [PMID: 34567656 PMCID: PMC8433474 DOI: 10.1038/s41378-020-0153-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 12/19/2019] [Accepted: 02/24/2020] [Indexed: 05/07/2023]
Abstract
Brain is one of the most temperature sensitive organs. Besides the fundamental role of temperature in cellular metabolism, thermal response of neuronal populations is also significant during the evolution of various neurodegenerative diseases. For such critical environmental factor, thorough mapping of cellular response to variations in temperature is desired in the living brain. So far, limited efforts have been made to create complex devices that are able to modulate temperature, and concurrently record multiple features of the stimulated region. In our work, the in vivo application of a multimodal photonic neural probe is demonstrated. Optical, thermal, and electrophysiological functions are monolithically integrated in a single device. The system facilitates spatial and temporal control of temperature distribution at high precision in the deep brain tissue through an embedded infrared waveguide, while it provides recording of the artefact-free electrical response of individual cells at multiple locations along the probe shaft. Spatial distribution of the optically induced temperature changes is evaluated through in vitro measurements and a validated multi-physical model. The operation of the multimodal microdevice is demonstrated in the rat neocortex and in the hippocampus to increase or suppress firing rate of stimulated neurons in a reversible manner using continuous wave infrared light (λ = 1550 nm). Our approach is envisioned to be a promising candidate as an advanced experimental toolset to reveal thermally evoked responses in the deep neural tissue.
Collapse
Affiliation(s)
- Ágoston Csaba Horváth
- Research Group for Implantable Microsystems, Faculty of Information Technology & Bionics, Pázmány Péter Catholic University, Budapest, Hungary
- Microsystems Laboratory, Institute for Technical Physics & Material Science, Centre for Energy Research, Budapest, Hungary
- Óbuda University Doctoral School on Materials Sciences and Technologies, Budapest, Hungary
| | - Sándor Borbély
- MTA TTK NAP Sleep Oscillations Research Group, Budapest, Hungary
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Örs Csanád Boros
- Department of Atomic Physics, Budapest University of Technology & Economics, Budapest, Hungary
| | - Lili Komáromi
- Department of Atomic Physics, Budapest University of Technology & Economics, Budapest, Hungary
| | - Pál Koppa
- Department of Atomic Physics, Budapest University of Technology & Economics, Budapest, Hungary
| | - Péter Barthó
- MTA TTK NAP Sleep Oscillations Research Group, Budapest, Hungary
| | - Zoltán Fekete
- Research Group for Implantable Microsystems, Faculty of Information Technology & Bionics, Pázmány Péter Catholic University, Budapest, Hungary
- Microsystems Laboratory, Institute for Technical Physics & Material Science, Centre for Energy Research, Budapest, Hungary
| |
Collapse
|
29
|
Khadka N, Truong DQ, Williams P, Martin JH, Bikson M. The Quasi-uniform assumption for Spinal Cord Stimulation translational research. J Neurosci Methods 2019; 328:108446. [PMID: 31589892 DOI: 10.1016/j.jneumeth.2019.108446] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Quasi-uniform assumption is a general theory that postulates local electric field predicts neuronal activation. Computational current flow model of spinal cord stimulation (SCS) of humans and animal models inform how the quasi-uniform assumption can support scaling neuromodulation dose between humans and translational animal. NEW METHOD Here we developed finite element models of cat and rat SCS, and brain slice, alongside SCS models. Boundary conditions related to species specific electrode dimensions applied, and electric fields per unit current (mA) predicted. RESULTS Clinically and across animal, electric fields change abruptly over small distance compared to the neuronal morphology, such that each neuron is exposed to multiple electric fields. Per unit current, electric fields generally decrease with body mass, but not necessarily and proportionally across tissues. Peak electric field in dorsal column rat and cat were ∼17x and ∼1x of clinical values, for scaled electrodes and equal current. Within the spinal cord, the electric field for rat, cat, and human decreased to 50% of peak value caudo-rostrally (C5-C6) at 0.48 mm, 3.2 mm, and 8 mm, and mediolaterally at 0.14 mm, 2.3 mm, and 3.1 mm. Because these space constants are different, electric field across species cannot be matched without selecting a region of interest (ROI). COMPARISON WITH EXISTING METHOD This is the first computational model to support scaling neuromodulation dose between humans and translational animal. CONCLUSIONS Inter-species reproduction of the electric field profile across the entire surface of neuron populations is intractable. Approximating quasi-uniform electric field in a ROI is a rational step to translational scaling.
Collapse
Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
| | - Dennis Q Truong
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Preston Williams
- Department of Molecular, Cellular, and Biomedical Sciences, City University of NY School of Medicine, New York, NY, 10031, USA
| | - John H Martin
- CUNY Graduate Center, New York, NY, 10031, USA; Department of Molecular, Cellular, and Biomedical Sciences, City University of NY School of Medicine, New York, NY, 10031, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
| |
Collapse
|
30
|
Caylor J, Reddy R, Yin S, Cui C, Huang M, Huang C, Rao R, Baker DG, Simmons A, Souza D, Narouze S, Vallejo R, Lerman I. Spinal cord stimulation in chronic pain: evidence and theory for mechanisms of action. Bioelectron Med 2019; 5:12. [PMID: 31435499 PMCID: PMC6703564 DOI: 10.1186/s42234-019-0023-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/30/2019] [Indexed: 12/30/2022] Open
Abstract
Well-established in the field of bioelectronic medicine, Spinal Cord Stimulation (SCS) offers an implantable, non-pharmacologic treatment for patients with intractable chronic pain conditions. Chronic pain is a widely heterogenous syndrome with regard to both pathophysiology and the resultant phenotype. Despite advances in our understanding of SCS-mediated antinociception, there still exists limited evidence clarifying the pathways recruited when patterned electric pulses are applied to the epidural space. The rapid clinical implementation of novel SCS methods including burst, high frequency and dorsal root ganglion SCS has provided the clinician with multiple options to treat refractory chronic pain. While compelling evidence for safety and efficacy exists in support of these novel paradigms, our understanding of their mechanisms of action (MOA) dramatically lags behind clinical data. In this review, we reconstruct the available basic science and clinical literature that offers support for mechanisms of both paresthesia spinal cord stimulation (P-SCS) and paresthesia-free spinal cord stimulation (PF-SCS). While P-SCS has been heavily examined since its inception, PF-SCS paradigms have recently been clinically approved with the support of limited preclinical research. Thus, wide knowledge gaps exist between their clinical efficacy and MOA. To close this gap, many rich investigative avenues for both P-SCS and PF-SCS are underway, which will further open the door for paradigm optimization, adjunctive therapies and new indications for SCS. As our understanding of these mechanisms evolves, clinicians will be empowered with the possibility of improving patient care using SCS to selectively target specific pathophysiological processes in chronic pain.
Collapse
Affiliation(s)
- Jacob Caylor
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Rajiv Reddy
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Sopyda Yin
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Christina Cui
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Mingxiong Huang
- Department of Radiology, University of California San Diego School of Medicine, La Jolla, CA USA
- Department of Radiology, VA San Diego Healthcare System, La Jolla, CA USA
| | - Charles Huang
- Department of Radiology, VA San Diego Healthcare System, La Jolla, CA USA
- Department of Bioengineering, Stanford University, Palo Alto, CA USA
| | - Ramesh Rao
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA USA
| | - Dewleen G. Baker
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA USA
- Department of Psychiatry, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Alan Simmons
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA USA
- Department of Psychiatry, University of California San Diego School of Medicine, La Jolla, CA USA
| | - Dmitri Souza
- Center for Pain Medicine, Western Reserve Hospital. Department of Surgery, Northeast Ohio Medical School (NEOMED), Athens, OH USA
| | - Samer Narouze
- Center for Pain Medicine, Western Reserve Hospital. Department of Surgery, Northeast Ohio Medical School (NEOMED), Athens, OH USA
| | - Ricardo Vallejo
- Basic Science Research, Millennium Pain Center, Bloomington, IL USA
- School of Biological Sciences, Illinois State University, Normal, IL USA
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL USA
| | - Imanuel Lerman
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA USA
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA USA
- Department of Radiology, VA San Diego Healthcare System, La Jolla, CA USA
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA USA
- Present Address: VA San Diego, 3350 La Jolla Village Dr, (MC116A), San Diego, CA 92161 USA
| |
Collapse
|
31
|
FallahRad M, Zannou AL, Khadka N, Prescott SA, Ratté S, Zhang T, Esteller R, Hershey B, Bikson M. Electrophysiology equipment for reliable study of kHz electrical stimulation. J Physiol 2019; 597:2131-2137. [PMID: 30816558 DOI: 10.1113/jp277654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 02/19/2019] [Indexed: 12/27/2022] Open
Abstract
Characterizing the cellular targets of kHz (1-10 kHz) electrical stimulation remains a pressing topic in neuromodulation because expanding interest in clinical application of kHz stimulation has surpassed mechanistic understanding. The presumed cellular targets of brain stimulation do not respond to kHz frequencies according to conventional electrophysiology theory. Specifically, the low-pass characteristics of cell membranes are predicted to render kHz stimulation inert, especially given the use of limited-duty-cycle biphasic pulses. Precisely because kHz frequencies are considered supra-physiological, conventional instruments designed for neurophysiological studies such as stimulators, amplifiers and recording microelectrodes do not operate reliably at these high rates. Moreover, for pulsed waveforms, the signal frequency content is well above the pulse repetition rate. Thus, the very tools used to characterize the effects of kHz electrical stimulation may themselves be confounding factors. We illustrate custom equipment design that supports reliable electrophysiological recording during kHz-rate stimulation. Given the increased importance of kHz stimulation in clinical domains and compelling possibilities that mechanisms of actions may reflect yet undiscovered neurophysiological phenomena, attention to suitable performance of electrophysiological equipment is pivotal.
Collapse
Affiliation(s)
- Mohamad FallahRad
- Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY, USA
| | - Adantchede Louis Zannou
- Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY, USA
| | - Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY, USA
| | - Steven A Prescott
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Physiology and Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, Canada
| | - Stéphanie Ratté
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Physiology and Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, Canada
| | - Tianhe Zhang
- Boston Scientific Neuromodulation, Valencia, CA, USA
| | | | - Brad Hershey
- Boston Scientific Neuromodulation, Valencia, CA, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY, USA
| |
Collapse
|
32
|
Abstract
Spinal cord stimulation (SCS) is a neuromodulation therapy used to treat medically refractory chronic pain. In SCS, an implanted pulse generator produces electrical signals that are conveyed through electrode arrays located in the region of the spinal cord. The goal of SCS is to modulate neural signaling through spinal and supraspinal mechanisms to reduce pain. Although available for decades, SCS still enjoys only limited clinical success, limited quality-of-life improvement, and limited long-term efficacy. To improve SCS outcomes, advances in lead design, stimulator features, and waveform paradigms have been recently introduced. While it is an exciting time for the neuromodulation field, empirical SCS advances have surpassed scientific understanding of SCS mechanisms of action. We still do not know why SCS works in some patients but not in others. We also lack information-rich biomarkers of pain and pain relief through which to optimize SCS programming. To optimize both system designs and clinical implementations of SCS, it is critical that we address these scientific and mechanistic knowledge gaps.
Collapse
Affiliation(s)
- Scott F. Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Parag G. Patil
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|