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Mojiri Z, Akhavan A, Rouhani E, Zahabi SJ. Quantitative analysis of noninvasive deep temporal interference stimulation: A simulation and experimental study. Heliyon 2024; 10:e29482. [PMID: 38655334 PMCID: PMC11035070 DOI: 10.1016/j.heliyon.2024.e29482] [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: 09/17/2023] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024] Open
Abstract
Background Deep brain stimulation (DBS) is a method for stimulating deep regions of the brain for the treatment of various neurological and psychiatric disorders such as depression, obsessive-compulsive disorder, addiction, and Parkinson's disease. Generally, DBS can be performed using both invasive and non-invasive approaches. Invasive DBS is associated with several problems, including intracranial bleeding, infection, and changes in the position of the electrode tip. Temporal interference (TI) stimulation is a non-invasive technique used to stimulate deep regions of the brain by applying two high-frequency sinusoidal currents with slightly different frequencies. New method This paper presents insights into the response of the spiking in the Hodgkin-Huxley (HH) neuron model of the rat somatosensory cortex by changing the parameters carrier frequency, current ratio, and difference frequency of TI stimulation. Furthermore, in order to experimentally evaluate the effect of TI stimulation on the activation of the left motor cortex, an experiment was conducted to measure the motion induced by the balanced and unbalanced TI stimulation. In the experiment, a three-axis accelerometer was attached to the right hand of the animal to determine the position of the hand. Results Simulation results of the HH model showed that the frequency of the envelope of the TI stimulation is identical to the fundamental frequency of the neuron spikes. This result was obtained for difference frequencies of 6 Hz and 9 Hz in balanced and unbalanced TI stimulations. Moreover specifically, when the difference frequency is set to zero, the carrier frequency is within the range of 1300-1400 Hz, and the current range is between 140 and 250 μA/cm2, the firing rate reached to its highest value. In the experimental result, the maximum range of movement at a difference frequency of Δf = 6 Hz was approximately 1.6 mm and 5.3 mm in the z and y directions respectively. Comparison with existing method The results of the spatial spectrum of the rat hand movement were consistent with the spectrum information of the simulation results. Additionally, steering the interfering region to the left motor cortex leads to noticeable contralateral movement of the right hand while no movement was observed in the right hand during the stimulation of the right motor cortex. Conclusion This technique of stimulation for the deep regions of the brain is a promising tool to noninvasively treat various neurological and psychiatric disorders such as morphine dependence in addicted rats.
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Affiliation(s)
- Zohre Mojiri
- Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Amir Akhavan
- Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Ehsan Rouhani
- Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Sayed Jalal Zahabi
- Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
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Su TF, Hamilton JD, Guo Y, Potas JR, Shivdasani MN, Moalem-Taylor G, Fridman GY, Aplin FP. Peripheral direct current reduces naturally evoked nociceptive activity at the spinal cord in rodent models of pain. J Neural Eng 2024; 21:026044. [PMID: 38579742 DOI: 10.1088/1741-2552/ad3b6c] [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: 08/25/2023] [Accepted: 04/05/2024] [Indexed: 04/07/2024]
Abstract
Objective.Electrical neuromodulation is an established non-pharmacological treatment for chronic pain. However, existing devices using pulsatile stimulation typically inhibit pain pathways indirectly and are not suitable for all types of chronic pain. Direct current (DC) stimulation is a recently developed technology which affects small-diameter fibres more strongly than pulsatile stimulation. Since nociceptors are predominantly small-diameter Aδand C fibres, we investigated if this property could be applied to preferentially reduce nociceptive signalling.Approach.We applied a DC waveform to the sciatic nerve in rats of both sexes and recorded multi-unit spinal activity evoked at the hindpaw using various natural stimuli corresponding to different sensory modalities rather than broad-spectrum electrical stimulus. To determine if DC neuromodulation is effective across different types of chronic pain, tests were performed in models of neuropathic and inflammatory pain.Main results.We found that in both pain models tested, DC application reduced responses evoked by noxious stimuli, as well as tactile-evoked responses which we suggest may be involved in allodynia. Different spinal activity of different modalities were reduced in naïve animals compared to the pain models, indicating that physiological changes such as those mediated by disease states could play a larger role than previously thought in determining neuromodulation outcomes.Significance.Our findings support the continued development of DC neuromodulation as a method for reduction of nociceptive signalling, and suggests that it may be effective at treating a broader range of aberrant pain conditions than existing devices.
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Affiliation(s)
- Tom F Su
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jack D Hamilton
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Yiru Guo
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jason R Potas
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
- Eccles Institute, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Mohit N Shivdasani
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Gila Moalem-Taylor
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Gene Y Fridman
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Felix P Aplin
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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Sagalajev B, Zhang T, Abdollahi N, Yousefpour N, Medlock L, Al-Basha D, Ribeiro-da-Silva A, Esteller R, Ratté S, Prescott SA. Absence of paresthesia during high-rate spinal cord stimulation reveals importance of synchrony for sensations evoked by electrical stimulation. Neuron 2024; 112:404-420.e6. [PMID: 37972595 DOI: 10.1016/j.neuron.2023.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/24/2023] [Accepted: 10/18/2023] [Indexed: 11/19/2023]
Abstract
Electrically activating mechanoreceptive afferents inhibits pain. However, paresthesia evoked by spinal cord stimulation (SCS) at 40-60 Hz becomes uncomfortable at high pulse amplitudes, limiting SCS "dosage." Kilohertz-frequency SCS produces analgesia without paresthesia and is thought, therefore, not to activate afferent axons. We show that paresthesia is absent not because axons do not spike but because they spike asynchronously. In a pain patient, selectively increasing SCS frequency abolished paresthesia and epidurally recorded evoked compound action potentials (ECAPs). Dependence of ECAP amplitude on SCS frequency was reproduced in pigs, rats, and computer simulations and is explained by overdrive desynchronization: spikes desychronize when axons are stimulated faster than their refractory period. Unlike synchronous spikes, asynchronous spikes fail to produce paresthesia because their transmission to somatosensory cortex is blocked by feedforward inhibition. Our results demonstrate how stimulation frequency impacts synchrony based on axon properties and how synchrony impacts sensation based on circuit properties.
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Affiliation(s)
- Boriss Sagalajev
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Tianhe Zhang
- Boston Scientific Neuromodulation, Valencia, CA 25155, USA
| | - Nooshin Abdollahi
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Noosha Yousefpour
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Laura Medlock
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Dhekra Al-Basha
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alfredo Ribeiro-da-Silva
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | | | - Stéphanie Ratté
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Steven A Prescott
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Yeung AM, Huang J, Nguyen KT, Xu NY, Hughes LT, Agrawal BK, Ejskjaer N, Klonoff DC. Spinal Cord Stimulation for Painful Diabetic Neuropathy. J Diabetes Sci Technol 2024; 18:168-192. [PMID: 36384312 PMCID: PMC10899837 DOI: 10.1177/19322968221133795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Spinal cord stimulation (SCS) technology has been recently approved by the US Food and Drug Administration (FDA) for painful diabetic neuropathy (PDN). The treatment involves surgical implantation of electrodes and a power source that delivers electrical current to the spinal cord. This treatment decreases the perception of pain in many chronic pain conditions, such as PDN. The number of patients with PDN treated with SCS and the amount of data describing their outcomes is expected to increase given four factors: (1) the large number of patients with this diagnosis, (2) the poor results that have been obtained for pain relief with pharmacotherapy and noninvasive non-pharmacotherapy, (3) the results to date with investigational SCS technology, and (4) the recent FDA approval of systems that deliver this treatment. Whereas traditional SCS replaces pain with paresthesias, a new form of SCS, called high-frequency 10-kHz SCS, first used for pain in 2015, can relieve PDN pain without causing paresthesias, although not all patients experience pain relief by SCS. This article describes (1) an overview of SCS technology, (2) the use of SCS for diseases other than diabetes, (3) the use of SCS for PDN, (4) a comparison of high-frequency 10-kHz and traditional SCS for PDN, (5) other SCS technology for PDN, (6) deployment of SCS systems, (7) barriers to the use of SCS for PDN, (8) risks of SCS technology, (9) current recommendations for using SCS for PDN, and (10) future developments in SCS.
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Affiliation(s)
| | | | | | - Nicole Y. Xu
- Diabetes Technology Society, Burlingame, CA, USA
| | - Lorenzo T. Hughes
- Balance Health, San Francisco, CA, USA
- Mills-Peninsula Medical Center, Burlingame, CA, USA
| | | | - Niels Ejskjaer
- Steno Diabetes Center North Denmark and Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - David C. Klonoff
- Diabetes Technology Society, Burlingame, CA, USA
- Diabetes Research Institute, Mills-Peninsula Medical Center, San Mateo, CA, USA
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Caussade T, Paduro E, Courdurier M, Cerpa E, Grill WM, Medina LE. Towards a more accurate quasi-static approximation of the electric potential for neurostimulation with kilohertz-frequency sources . J Neural Eng 2023; 20:10.1088/1741-2552/ad1612. [PMID: 38100821 PMCID: PMC10822676 DOI: 10.1088/1741-2552/ad1612] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/15/2023] [Indexed: 12/17/2023]
Abstract
Objective.Our goal was to determine the conditions for which a more precise calculation of the electric potential than the quasi-static approximation may be needed in models of electrical neurostimulation, particularly for signals with kilohertz-frequency components.Approach.We conducted a comprehensive quantitative study of the differences in nerve fiber activation and conduction block when using the quasi-static and Helmholtz approximations for the electric potential in a model of electrical neurostimulation.Main results.We first show that the potentials generated by sources of unbalanced pulses exhibit different transients as compared to those of charge-balanced pulses, and this is disregarded by the quasi-static assumption. Secondly, relative errors for current-distance curves were below 3%, while for strength-duration curves these ranged between 1%-17%, but could be improved to less than 3% across the range of pulse duration by providing a corrected quasi-static conductivity. Third, we extended our analysis to trains of pulses and reported a 'congruence area' below 700 Hz, where the fidelity of fiber responses is maximal for supra-threshold stimulation. Further examination of waveforms and polarities revealed similar fidelities in the congruence area, but significant differences were observed beyond this area. However, the spike-train distance revealed differences in activation patterns when comparing the response generated by each model. Finally, in simulations of conduction-block, we found that block thresholds exhibited errors above 20% for repetition rates above 10 kHz. Yet, employing a corrected value of the conductivity improved the agreement between models, with errors no greater than 8%.Significance.Our results emphasize that the quasi-static approximation cannot be naively extended to electrical stimulation with high-frequency components, and notable differences can be observed in activation patterns. As well, we introduce a methodology to obtain more precise model responses using the quasi-static approach, retaining its simplicity, which can be a valuable resource in computational neuroengineering.
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Affiliation(s)
- Thomas Caussade
- Instituto de Ingeniería Matemática y Computacional, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago Chile
| | - Esteban Paduro
- Instituto de Ingeniería Matemática y Computacional, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago Chile
| | - Matías Courdurier
- Departamento de Matemática, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Cerpa
- Instituto de Ingeniería Matemática y Computacional, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago Chile
| | - Warren M. Grill
- Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Department of Neurobiology, Department of Neurosurgery, Duke University, Durham, NC, USA
| | - Leonel E. Medina
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile
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Jin MY, D'Souza RS, Abd-Elsayed AA. Efficacy of Neuromodulation Interventions for the Treatment of Sexual Dysfunction: A Systematic Review. Neuromodulation 2023; 26:1518-1534. [PMID: 35981957 DOI: 10.1016/j.neurom.2022.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/11/2022] [Accepted: 07/12/2022] [Indexed: 12/20/2022]
Abstract
OBJECTIVES The primary aim of this review was to analyze the literature for the efficacy of neuromodulation interventions in treating both male and female sexual dysfunction. MATERIALS AND METHODS Studies were identified from PubMed, Scopus, PsychINFO, CINAHL, and Cochrane. Results were synthesized qualitatively without pooling owing to the heterogeneous nature of outcome assessments. RESULTS Overall findings from studies generally supported that neuromodulation interventions were associated with improvement in sexual function. Specific domains that improved in male patients included erectile function, desire, and satisfaction, whereas desire, arousal, orgasm, lubrication, quality of "sex life," intercourse capability, and dyspareunia improved in female patients. Male ejaculation, orgasm, and intercourse capability were the only domains that continued to decline after the use of neuromodulation interventions, although this was only reported in one study. CONCLUSION Our review suggests that there may be promise and potential utility of neuromodulation in improving sexual dysfunction; however, further research is needed.
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Affiliation(s)
- Max Y Jin
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA; Mayo Clinic, Rochester, MN, USA
| | - Ryan S D'Souza
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Alaa A Abd-Elsayed
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA; Mayo Clinic, Rochester, MN, USA.
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Rogers ER, Mirzakhalili E, Lempka SF. Model-based analysis of subthreshold mechanisms of spinal cord stimulation for pain. J Neural Eng 2023; 20:066003. [PMID: 37906966 PMCID: PMC10632558 DOI: 10.1088/1741-2552/ad0858] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/11/2023] [Accepted: 10/31/2023] [Indexed: 11/02/2023]
Abstract
Objective.Spinal cord stimulation (SCS) is a common treatment for chronic pain. For decades, SCS maximized overlap between stimulation-induced paresthesias and the patient's painful areas. Recently developed SCS paradigms relieve pain at sub-perceptible amplitudes, yet little is known about the neural response to these new waveforms or their analgesic mechanisms of action. Therefore, in this study, we investigated the neural response to multiple forms of paresthesia-free SCS.Approach.We used computational modeling to investigate the neurophysiological effects and the plausibility of commonly proposed mechanisms of three paresthesia-free SCS paradigms: burst, 1 kHz, and 10 kHz SCS. Specifically, in C- and Aβ-fibers, we investigated the effects of different SCS waveforms on spike timing and activation thresholds, as well as how stochastic ion channel gating affects the response of dorsal column axons. Finally, we characterized membrane polarization of superficial dorsal horn neurons.Main results.We found that none of the SCS waveforms activate nor modulate spike timing in C-fibers. Spike timing was modulated in Aβ-fibers only at suprathreshold amplitudes. Ion channel stochasticity had little effect on Aβ-fiber activation thresholds but produced heterogeneous spike timings at suprathreshold amplitudes. Finally, local cells were preferentially polarized in their axon terminals, and the magnitude of this polarization was dependent on cellular morphology and position relative to the stimulation electrodes.Significance.Overall, the mechanisms of action of subparesthetic SCS remain unclear. Our results suggest that no SCS waveforms directly activate C-fibers, and modulation of spike timing is unlikely at subthreshold amplitudes. We conclude that potential subthreshold neuromodulatory effects of SCS on local cells are likely to be presynaptic in nature, as axons are preferentially depolarized during SCS.
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Affiliation(s)
- Evan R Rogers
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Ehsan Mirzakhalili
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States of America
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Yang CT, Guan Y, Chen CC, Lin WT, Lu KH, Lin CR, Shyu BC, Wen YR. Novel Pulsed Ultrahigh-frequency Spinal Cord Stimulation Inhibits Mechanical Hypersensitivity and Brain Neuronal Activity in Rats after Nerve Injury. Anesthesiology 2023; 139:646-663. [PMID: 37428715 DOI: 10.1097/aln.0000000000004680] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
BACKGROUND Spinal cord stimulation (SCS) is an important pain treatment modality. This study hypothesized that a novel pulsed ultrahigh-frequency spinal cord stimulation (pUHF-SCS) could safely and effectively inhibit spared nerve injury-induced neuropathic pain in rats. METHODS Epidural pUHF-SCS (± 3V, 2-Hz pulses comprising 500-kHz biphasic sinewaves) was implanted at the thoracic vertebrae (T9 to T11). Local field brain potentials after hind paw stimulation were recorded. Analgesia was evaluated by von Frey-evoked allodynia and acetone-induced cold allodynia. RESULTS The mechanical withdrawal threshold of the injured paw was 0.91 ± 0.28 g lower than that of the sham surgery (24.9 ± 1.2 g). Applying 5-, 10-, or 20-min pUHF-SCS five times every 2 days significantly increased the paw withdrawal threshold to 13.3 ± 6.5, 18.5 ± 3.6, and 21.0 ± 2.8 g at 5 h post-SCS, respectively (P = 0.0002, < 0.0001, and < 0.0001; n = 6 per group) and to 6.1 ± 2.5, 8.2 ± 2.7, and 14.3 ± 5.9 g on the second day, respectively (P = 0.123, 0.013, and < 0.0001). Acetone-induced paw response numbers decreased from pre-SCS (41 ± 12) to 24 ± 12 and 28 ± 10 (P = 0.006 and 0.027; n = 9) at 1 and 5 h after three rounds of 20-min pUHF-SCS, respectively. The areas under the curve from the C component of the evoked potentials at the left primary somatosensory and anterior cingulate cortices were significantly decreased from pre-SCS (101.3 ± 58.3 and 86.9 ± 25.5, respectively) to 39.7 ± 40.3 and 36.3 ± 20.7 (P = 0.021, and 0.003; n = 5) at 60 min post-SCS, respectively. The intensity thresholds for pUHF-SCS to induce brain and sciatic nerve activations were much higher than the therapeutic intensities and thresholds of conventional low-frequency SCS. CONCLUSIONS Pulsed ultrahigh-frequency spinal cord stimulation inhibited neuropathic pain-related behavior and paw stimulation evoked brain activation through mechanisms distinct from low-frequency SCS. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Chin-Tsang Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; and Department of Leisure Industry and Health Promotion, National Ilan University, Yilan, Taiwan
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Department of Neurological Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan; and Taiwan Mouse Clinic, Biomedical Translational Research Center, Academia Sinica, Taipei, Taiwan
| | | | - Kuo-Hsiang Lu
- Kuo-Hsiang Lu, M.S.; Gimer Medical Co., New Taipei City, Taiwan
| | - Chung-Ren Lin
- Department of Anesthesiology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Bai-Chuang Shyu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yeong-Ray Wen
- Pain Management and Research Center, Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan; and College of Medicine, China Medical University, Taichung, Taiwan
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Dewberry LS, Porche K, Koenig T, Allen KD, Otto KJ. High frequency alternating current neurostimulation decreases nocifensive behavior in a disc herniation model of lumbar radiculopathy. Bioelectron Med 2023; 9:15. [PMID: 37434246 DOI: 10.1186/s42234-023-00119-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 06/19/2023] [Indexed: 07/13/2023] Open
Abstract
BACKGROUND The purpose of this study was to evaluate if kilohertz frequency alternating current (KHFAC) stimulation of peripheral nerve could serve as a treatment for lumbar radiculopathy. Prior work shows that KHFAC stimulation can treat sciatica resulting from chronic sciatic nerve constriction. Here, we evaluate if KHFAC stimulation is also beneficial in a more physiologic model of low back pain which mimics nucleus pulposus (NP) impingement of a lumbar dorsal root ganglion (DRG). METHODS To mimic a lumbar radiculopathy, autologous tail NP was harvested and placed upon the right L5 nerve root and DRG. During the same surgery, a cuff electrode was implanted around the sciatic nerve with wires routed to a headcap for delivery of KHFAC stimulation. Male Lewis rats (3 mo., n = 18) were separated into 3 groups: NP injury + KHFAC stimulation (n = 7), NP injury + sham cuff (n = 6), and sham injury + sham cuff (n = 5). Prior to surgery and for 2 weeks following surgery, animal tactile sensitivity, gait, and static weight bearing were evaluated. RESULTS KHFAC stimulation of the sciatic nerve decreased behavioral evidence of pain and disability. Without KHFAC stimulation, injured animals had heightened tactile sensitivity compared to baseline (p < 0.05), with tactile allodynia reversed during KHFAC stimulation (p < 0.01). Midfoot flexion during locomotion was decreased after injury but improved with KHFAC stimulation (p < 0.05). Animals also placed more weight on their injured limb when KHFAC stimulation was applied (p < 0.05). Electrophysiology measurements at end point showed decreased, but not blocked, compound nerve action potentials with KHFAC stimulation (p < 0.05). CONCLUSIONS KHFAC stimulation decreases hypersensitivity but does not cause additional gait compensations. This supports the idea that KHFAC stimulation applied to a peripheral nerve may be able to treat chronic pain resulting from sciatic nerve root inflammation.
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Affiliation(s)
- Lauren Savannah Dewberry
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr. JG56, P.O. Box 116131, Gainesville, FL, 32611, USA
| | - Ken Porche
- Lillian S Wells Department of Neurosurgery at the University of Florida, College of Medicine, 1505 SW Archer Road Gainesville, FL, 32608, Gainesville, USA
| | - Travis Koenig
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr. JG56, P.O. Box 116131, Gainesville, FL, 32611, USA
| | - Kyle D Allen
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr. JG56, P.O. Box 116131, Gainesville, FL, 32611, USA
- Pain Research & Intervention Center of Excellence, University of Florida, CTSI 2004 Mowry Road, Gainesville, FL, USA
- Department of Orthopedics and Sports Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Kevin J Otto
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr. JG56, P.O. Box 116131, Gainesville, FL, 32611, USA.
- Department of Neuroscience, University of Florida, 1149 Newell Dr. L1-100, P.O. Box 100244, Gainesville, FL, USA.
- Department of Electrical and Computer Engineering, University of Florida, 968 Center Dr, Gainesville, FL, 32611, USA.
- Department of Chemical Engineering, University of Florida, 1030 Center Drive, P.O. Box 116005, Gainesville, FL, 32611, USA.
- Department of Materials Science and Engineering, University of Florida, 549 Gale Lemerand Dr, P.O. Box 116400, Gainesville, FL, 32611, USA.
- Department of Neurology, 1149 Newell Dr, P.O. Box 100236, Gainesville, FL, L3-10032610, USA.
- Nanoscience Institute for Medical and Engineering Technology (NIMET), University of Florida, 1041 Center Drive, Gainesville, FL, 32611, USA.
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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.
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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;
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11
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Kuo SW, Zhang T, Esteller R, Grill WM. In Vivo Measurements reveal that both low- and high-frequency spinal cord stimulation heterogeneously modulate superficial dorsal horn neurons. Neuroscience 2023; 520:119-131. [PMID: 37085007 DOI: 10.1016/j.neuroscience.2023.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 03/01/2023] [Accepted: 04/08/2023] [Indexed: 04/23/2023]
Abstract
Current sub-perception spinal cord stimulation (SCS) is characterized by the use of high-frequency pulses to achieve paresthesia-free analgesic effects. High-frequency SCS demonstrates distinctive properties from paresthesia-based SCS, such as a longer time course to response, implying the existence of alternative mechanism(s) of action beyond gate control theory. We quantified the responses to SCS of single neurons within the superficial dorsal horn (SDH), a structure in close proximity to SCS electrodes, to investigate the mechanisms underlying high-frequency SCS in 62 urethane-anesthetized male rats. Sciatic nerve stimulation was delivered to isolate lumbar SDH neurons with evoked C-fiber activity. The evoked C-fiber activity before and after the application of SCS was compared to quantify the effects of SCS across stimulation intensity and stimulation duration at three different stimulation frequencies. We observed heterogeneous responses of SDH neurons which depended primarily on the type of unit. Low-threshold units with spontaneous activity, putatively inhibitory interneurons, tended to be facilitated by SCS while the other unit types were suppressed. The effects of SCS were more prominent with increased stimulation duration from 30 s to 30 m across frequencies. Our results highlight the importance of inhibitory interneurons in modulating local circuits of the SDH and the importance of local circuit contributions to the analgesic mechanisms of SCS.
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Affiliation(s)
- Su-Wei Kuo
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Tianhe Zhang
- Division of Neuromodulation, Boston Scientific Corporation, CA
| | - Rosana Esteller
- Division of Neuromodulation, Boston Scientific Corporation, CA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC; Departments of Electrical and Computer Engineering, Neurobiology, and Neurosurgery, Duke University, Durham, NC.
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12
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Dalrymple AN, Hooper CA, Kuriakose MG, Capogrosso M, Weber DJ. Using a high-frequency carrier does not improve comfort of transcutaneous spinal cord stimulation. J Neural Eng 2023; 20. [PMID: 36595241 DOI: 10.1088/1741-2552/acabe8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Objective.Spinal cord neuromodulation has gained much attention for demonstrating improved motor recovery in people with spinal cord injury, motivating the development of clinically applicable technologies. Among them, transcutaneous spinal cord stimulation (tSCS) is attractive because of its non-invasive profile. Many tSCS studies employ a high-frequency (10 kHz) carrier, which has been reported to reduce stimulation discomfort. However, these claims have come under scrutiny in recent years. The purpose of this study was to determine whether using a high-frequency carrier for tSCS is more comfortable at therapeutic amplitudes, which evoke posterior root-muscle (PRM) reflexes.Approach.In 16 neurologically intact participants, tSCS was delivered using a 1 ms long monophasic pulse with and without a high-frequency carrier. Stimulation amplitude and pulse duration were varied and PRM reflexes were recorded from the soleus, gastrocnemius, and tibialis anterior muscles. Participants rated their discomfort during stimulation from 0 to 10 at PRM reflex threshold.Main Results.At PRM reflex threshold, the addition of a high-frequency carrier (0.87 ± 0.2) was equally comfortable as conventional stimulation (1.03 ± 0.18) but required approximately double the charge to evoke the PRM reflex (conventional: 32.4 ± 9.2µC; high-frequency carrier: 62.5 ± 11.1µC). Strength-duration curves for tSCS with a high-frequency carrier had a rheobase that was 4.8× greater and a chronaxie that was 5.7× narrower than the conventional monophasic pulse, indicating that the addition of a high-frequency carrier makes stimulation less efficient in recruiting neural activity in spinal roots.Significance.Using a high-frequency carrier for tSCS is equally as comfortable and less efficient as conventional stimulation at amplitudes required to stimulate spinal dorsal roots.
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Affiliation(s)
- Ashley N Dalrymple
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Charli Ann Hooper
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Minna G Kuriakose
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Marco Capogrosso
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, United States of America.,Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Douglas J Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America.,Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, United States of America
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13
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Chang YC, Ahmed U, Jayaprakash N, Mughrabi I, Lin Q, Wu YC, Gerber M, Abbas A, Daytz A, Gabalski AH, Ashville J, Dokos S, Rieth L, Datta-Chaudhuri T, Tracey KJ, Guo T, Al-Abed Y, Zanos S. kHz-frequency electrical stimulation selectively activates small, unmyelinated vagus afferents. Brain Stimul 2022; 15:1389-1404. [PMID: 36241025 PMCID: PMC10164362 DOI: 10.1016/j.brs.2022.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/02/2022] [Accepted: 09/30/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Vagal reflexes regulate homeostasis in visceral organs and systems through afferent and efferent neurons and nerve fibers. Small, unmyelinated, C-type afferents comprise over 80% of fibers in the vagus and form the sensory arc of autonomic reflexes of the gut, lungs, heart and vessels and the immune system. Selective bioelectronic activation of C-afferents could be used to mechanistically study and treat diseases of peripheral organs in which vagal reflexes are involved, but it has not been achieved. METHODS We stimulated the vagus in rats and mice using trains of kHz-frequency stimuli. Stimulation effects were assessed using neuronal c-Fos expression, physiological and nerve fiber responses, optogenetic and computational methods. RESULTS Intermittent kHz stimulation for 30 min activates specific motor and, preferentially, sensory vagus neurons in the brainstem. At sufficiently high frequencies (>5 kHz) and at intensities within a specific range (7-10 times activation threshold, T, in rats; 15-25 × T in mice), C-afferents are activated, whereas larger, A- and B-fibers, are blocked. This was determined by measuring fiber-specific acute physiological responses to kHz stimulus trains, and by assessing fiber excitability around kHz stimulus trains through compound action potentials evoked by probing pulses. Aspects of selective activation of C-afferents are explained in computational models of nerve fibers by how fiber size and myelin shape the response of sodium channels to kHz-frequency stimuli. CONCLUSION kHz stimulation is a neuromodulation strategy to robustly and selectively activate vagal C-afferents implicated in physiological homeostasis and disease, over larger vagal fibers.
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Affiliation(s)
- Yao-Chuan Chang
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Umair Ahmed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Naveen Jayaprakash
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Ibrahim Mughrabi
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Qihang Lin
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
| | - Yi-Chen Wu
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Michael Gerber
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Adam Abbas
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Anna Daytz
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Arielle H Gabalski
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Jason Ashville
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Socrates Dokos
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
| | - Loren Rieth
- Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV, 26506, United States
| | - Timir Datta-Chaudhuri
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Kevin J Tracey
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Tianruo Guo
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
| | - Yousef Al-Abed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, United States; Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States.
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14
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Bandres MF, Gomes JL, McPherson JG. Spinal stimulation for motor rehabilitation immediately modulates nociceptive transmission. J Neural Eng 2022; 19:10.1088/1741-2552/ac9a00. [PMID: 36228593 PMCID: PMC9797038 DOI: 10.1088/1741-2552/ac9a00] [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: 04/06/2022] [Accepted: 10/13/2022] [Indexed: 12/31/2022]
Abstract
Objective. Spinal cord injury (SCI) often results in debilitating movement impairments and neuropathic pain. Electrical stimulation of spinal neurons holds considerable promise both for enhancing neural transmission in weakened motor pathways and for reducing neural transmission in overactive nociceptive pathways. However, spinal stimulation paradigms currently under development for individuals living with SCI continue overwhelmingly to be developed in the context of motor rehabilitation alone. The objective of this study is to test the hypothesis that motor-targeted spinal stimulation simultaneously modulates spinal nociceptive transmission.Approach. We characterized the neuromodulatory actions of motor-targeted intraspinal microstimulation (ISMS) on the firing dynamics of large populations of discrete nociceptive specific and wide dynamic range (WDR) neurons. Neurons were accessed via dense microelectrode arrays implantedin vivointo lumbar enlargement of rats. Nociceptive and non-nociceptive cutaneous transmission was induced before, during, and after ISMS by mechanically probing the L5 dermatome.Main results. Our primary findings are that (a) sub-motor threshold ISMS delivered to spinal motor pools immediately modulates concurrent nociceptive transmission; (b) the magnitude of anti-nociceptive effects increases with longer durations of ISMS, including robust carryover effects; (c) the majority of all identified nociceptive-specific and WDR neurons exhibit firing rate reductions after only 10 min of ISMS; and (d) ISMS does not increase spinal responsiveness to non-nociceptive cutaneous transmission. These results lead to the conclusion that ISMS parameterized to enhance motor output results in an overall net decrease n spinal nociceptive transmission.Significance. These results suggest that ISMS may hold translational potential for neuropathic pain-related applications and that it may be uniquely suited to delivering multi-modal therapeutic benefits for individuals living with SCI.
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Affiliation(s)
- Maria F. Bandres
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
- Department of Biomedical Engineering; Washington University in St. Louis
| | - Jefferson L. Gomes
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
| | - Jacob G. McPherson
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
- Department of Anesthesiology, Washington University School of Medicine in St. Louis
- Washington University Pain Center, Washington University School of Medicine in St. Louis
- Program in Neuroscience; Washington University School of Medicine in St. Louis
- Department of Biomedical Engineering; Washington University in St. Louis
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15
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Managing Chronic Neuropathic Pain: Recent Advances and New Challenges. Neurol Res Int 2022; 2022:8336561. [PMID: 36277331 PMCID: PMC9581623 DOI: 10.1155/2022/8336561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/03/2022] [Accepted: 08/07/2022] [Indexed: 11/17/2022] Open
Abstract
Aim. Neuropathic pain affects 7–10% of the population, with most of the patients receiving inadequate and incomplete treatment. Owing to the high financial burden and the poor quality of life of the patients and their caretakers, there is a dire need to address the challenges in diagnosing and treating chronic neuropathic pain. Methods. This literature review was conducted to review novel treatments and related challenges through a systematic search from sources such as PubMed, Google Scholar with the combination of MESH words such as neuropathic pain, management of neuropathic pain. Articles from non-English literature, reports without human subjects, animal studies, and abstracts/posters were excluded. However, human studies and studies published in English were included. Result. This review article discusses novel treatment modalities while acknowledging the challenges medical workers face while encountering neuropathic pain. Despite the recent advances in diagnosis and treatment modalities, several challenges still exist. Hence, there is still a need to explore the various treatment modalities, emphasizing the cause and underlying pathophysiology of neuropathic pain. Conclusion. We recommend integrated multimodal treatment with the current treatment facility, including various medical disciplines. However, a personalized approach would work the best depending on the ’patient’s medical history. Therefore, this article recommends an integrated, cause-specific, cost-effective approach to address this problem of chronic neuropathic pain.
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16
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Surround Inhibition Mediates Pain Relief by Low Amplitude Spinal Cord Stimulation: Modeling and Measurement. eNeuro 2022; 9:ENEURO.0058-22.2022. [PMID: 36150892 PMCID: PMC9536854 DOI: 10.1523/eneuro.0058-22.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 08/31/2022] [Accepted: 09/17/2022] [Indexed: 12/15/2022] Open
Abstract
Low-frequency (<200 Hz), subperception spinal cord stimulation (SCS) is a novel modality demonstrating therapeutic efficacy for treating chronic neuropathic pain. When stimulation parameters were carefully titrated, patients experienced rapid onset (seconds-minutes) pain relief without paresthesia, but the mechanisms of action are unknown. Using an integrated computational model and in vivo measurements in urethane-anesthetized rats, we quantified how stimulation parameters (placement, pulse width, frequency, and amplitude) influenced dorsal column (DC) axon activation and neural responses in the dorsal horn (DH). Both modeled and recorded DC axons responded with irregular spiking patterns in response to low-amplitude SCS. Maximum inhibition of DH neurons occurred at ∼80% of the predicted sensory threshold in both modeled and recorded neurons, and responses were strongly dependent on spatially targeting of stimulation, i.e., the complement of DC axons activated, and on stimulation parameters. Intrathecal administration of bicuculline shifted neural responses to low-amplitude stimulation in both the model and experiment, suggesting that analgesia is dependent on segmental GABAergic mechanisms. Our results support the hypothesis that low-frequency subperception SCS generates rapid analgesia by activating a small number of DC axons which inhibit DH neuron activity via surround inhibition.
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17
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D’Souza RS, Her YF, Jin MY, Morsi M, Abd-Elsayed A. Neuromodulation Therapy for Chemotherapy-Induced Peripheral Neuropathy: A Systematic Review. Biomedicines 2022; 10:1909. [PMID: 36009456 PMCID: PMC9405804 DOI: 10.3390/biomedicines10081909] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/31/2022] [Accepted: 08/04/2022] [Indexed: 11/26/2022] Open
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and painful condition in patients who have received chemotherapy. The role of neuromodulation therapy in treating pain and improving neurological function in CIPN remains unclear and warrants evidence appraisal. In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a systematic review to assess change in pain intensity and neurological function after implementation of any neuromodulation intervention for CIPN. Neuromodulation interventions consisted of dorsal column spinal cord stimulation (SCS), dorsal root ganglion stimulation (DRG-S), or peripheral nerve stimulation (PNS). In total, 15 studies utilized SCS (16 participants), 7 studies utilized DRG-S (7 participants), and 1 study utilized PNS (50 participants). Per the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria, there was very low-quality GRADE evidence supporting that dorsal column SCS, DRG-S, and PNS are associated with a reduction in pain severity from CIPN. Results on changes in neurological function remained equivocal due to mixed study findings on thermal sensory thresholds and touch sensation or discrimination. Future prospective, well-powered, and comparative studies assessing neuromodulation for CIPN are warranted.
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Affiliation(s)
- Ryan S. D’Souza
- Department of Anesthesiology and Perioperative Medicine, Division of Pain Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Yeng F. Her
- Department of Anesthesiology and Perioperative Medicine, Division of Pain Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Max Y. Jin
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53706, USA
| | - Mahmoud Morsi
- Department of Anesthesiology, John H. Stroger, Jr. Hospital of Cook County, Chicago, IL 60621, USA
| | - Alaa Abd-Elsayed
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53706, USA
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18
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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: 22] [Impact Index Per Article: 7.3] [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.
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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
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19
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Chen J, Jian J, Wang J, Shen Z, Shen B, Wang W, Beckel J, de Groat WC, Chermansky C, Tai C. Low pressure voiding induced by stimulation and 1 kHz post-stimulation block of the pudendal nerves in cats. Exp Neurol 2021; 346:113860. [PMID: 34487735 DOI: 10.1016/j.expneurol.2021.113860] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/27/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022]
Abstract
The goal of this study is to induce low-pressure voiding by stimulation and bilateral 1 kHz post-stimulation block of the pudendal nerves. In anesthetized cats, wire hook electrodes were placed on the left and/or right pudendal nerves. Stimulus pulses (30 Hz, 0.2 ms) were applied to one pudendal nerve to induce a reflex bladder contraction and to produce contractions of the external urethral sphincter (EUS). High frequency (1 kHz) biphasic stimulation was applied to block axonal conduction in both pudendal nerves and block EUS activity. In 4 cats, a catheter was inserted into the distal urethra to perfuse and measure the back pressure caused by the EUS contraction. In another 5 cats, a catheter was inserted into the bladder dome and the urethra was left open to allow voiding. The 1 kHz stimulation (30-60 s, 0.5-5 mA) delivered via a wire hook electrode completely blocked pudendal nerve conduction for ≥2 min after terminating the stimulation, i.e., a post-stimulation block. The block gradually disappeared in 6-18 min. The block duration increased with increasing amplitude or duration of the 1 kHz stimulation. Without the 1 kHz block, 30 Hz stimulation alone induced high-pressure (90 cmH2O) voiding. When combined with the 1 kHz block, the 30 Hz stimulation induced low-pressure (≤50 cmH2O) voiding with a high voiding efficiency (80%). In summary, a minimally invasive surgical approach might be developed to restore voiding function after spinal cord injury by stimulation and block of the pudendal nerves using lead electrodes.
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Affiliation(s)
- Jialiang Chen
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Urology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Jianan Jian
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jicheng Wang
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zhijun Shen
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bing Shen
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
| | - William Wang
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan Beckel
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Changfeng Tai
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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20
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Tao X, Luo X, Zhang T, Hershey B, Esteller R, Ji RR. Spinal Cord Stimulation Attenuates Mechanical Allodynia and Increases Central Resolvin D1 Levels in Rats With Spared Nerve Injury. Front Physiol 2021; 12:687046. [PMID: 34248674 PMCID: PMC8267572 DOI: 10.3389/fphys.2021.687046] [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: 03/28/2021] [Accepted: 05/12/2021] [Indexed: 12/31/2022] Open
Abstract
Mounting evidence from animal models of inflammatory and neuropathic pain suggests that inflammation regulates the resolution of pain by producing specialized pro-resolving mediators (SPMs), such as resolvin D1 (RvD1). However, it remains unclear how SPMs are induced in the central nervous system and whether these mechanisms can be reconciled with outcomes of neuromodulation therapies for pain, such as spinal cord stimulation. Here, we show that in a male rat model of neuropathic pain produced by spared nerve injury (SNI), 1 kHz spinal cord stimulation (1 kHz SCS) alone was sufficient to reduce mechanical allodynia and increase RvD1 in the cerebrospinal fluid (CSF). SNI resulted in robust and persistent mechanical allodynia and cold allodynia. Spinal cord electrode implantation was conducted at the T11-T13 vertebral level 1 week after SNI. The spinal locations of the implanted electrodes were validated by X-Ray radiography. 1 kHz SCS was applied for 6 h at 0.1 ms pulse-width, and this stimulation alone was sufficient to effectively reduce nerve injury-induced mechanical allodynia during stimulation without affecting SNI-induced cold allodynia. SCS alone significantly reduced interleukin-1β levels in both serum and CSF samples. Strikingly, SCS significantly increased RvD1 levels in the CSF but not serum. Finally, intrathecal injection of RvD1 (100 and 500 ng, i.t.) 4 weeks after nerve injury reduced SNI-induced mechanical allodynia in a dose-dependent manner. Our findings suggest that 1 kHz SCS may alleviate neuropathic pain via reduction of IL-1β and via production and/or release of RvD1 to control SNI-induced neuroinflammation.
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Affiliation(s)
- Xueshu Tao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, United States.,Department of Pain Medicine, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Xin Luo
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, United States
| | - Tianhe Zhang
- Boston Scientific Neuromodulation Research and Advanced Concepts, Valencia, CA, United States
| | - Brad Hershey
- Boston Scientific Neuromodulation Research and Advanced Concepts, Valencia, CA, United States
| | - Rosana Esteller
- Boston Scientific Neuromodulation Research and Advanced Concepts, Valencia, CA, United States
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, United States.,Department of Cell Biology, Duke University Medical Center, Durham, NC, United States.,Department of Neurobiology, Duke University Medical Center, Durham, NC, United States
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21
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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: 32] [Impact Index Per Article: 10.7] [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.
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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.
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22
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Gmel GE, Santos Escapa R, Parker JL, Mugan D, Al-Kaisy A, Palmisani S. The Effect of Spinal Cord Stimulation Frequency on the Neural Response and Perceived Sensation in Patients With Chronic Pain. Front Neurosci 2021; 15:625835. [PMID: 33551738 PMCID: PMC7859107 DOI: 10.3389/fnins.2021.625835] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/05/2021] [Indexed: 11/30/2022] Open
Abstract
Background The effect of spinal cord stimulation (SCS) amplitude on the activation of dorsal column fibres has been widely studied through the recording of Evoked Compound Action Potentials (ECAPs), the sum of all action potentials elicited by an electrical stimulus applied to the fibres. ECAP amplitude grows linearly with stimulus current after a threshold, and a larger ECAP results in a stronger stimulus sensation for patients. This study investigates the effect of stimulus frequency on both the ECAP amplitude as well as the perceived stimulus sensation in patients undergoing SCS therapy for chronic back and/or leg pain. Methods Patients suffering with chronic neuropathic lower-back and/or lower-limb pain undergoing an epidural SCS trial were recruited. Patients were implanted according to standard practice, having two 8-contact leads (8 mm inter-electrode spacing) which overlapped 2–4 contacts around the T9/T10 interspace. Both lead together thus spanning about three vertebral levels. Neurophysiological recordings were taken during the patient’s trial phase at two routine follow-ups using a custom external stimulator capable of recording ECAPs in real-time from all non-stimulating contacts. Stimulation was performed at various vertebral levels, varying the frequency (ranging from 2 to 455 Hz) while all other stimulating variables were kept constant. During the experiments subjects were asked to rate the stimulation-induced sensation (paraesthesia) on a scale from 0 to 10. Results Frequency response curves showed an inverse relationship between stimulation sensation strength and ECAP amplitude, with higher frequencies generating smaller ECAPs but stronger stimulation-induced paraesthesia (at constant stimulation amplitude). Both relationships followed logarithmic trends against stimulus frequency meaning that the effects on ECAP amplitude and sensation are larger for smaller frequencies. Conclusion This work supports the hypothesis that SCS-induced paraesthesia is conveyed through both frequency coding and population coding, fitting known psychophysics of tactile sensory information processing. The inverse relationship between ECAP amplitude and sensation for increasing frequencies at fixed stimulus amplitude questions common assumptions of monotonic relationships between ECAP amplitude and sensation strength.
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Affiliation(s)
| | | | | | - Dave Mugan
- Saluda Medical Pty Ltd., Artarmon, NSW, Australia
| | - Adnan Al-Kaisy
- Guy's & St. Thomas' NHS Foundation Trust, London, United Kingdom
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23
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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.
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24
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Edhi MM, Heijmans L, Vanent KN, Bloye K, Baanante A, Jeong KS, Leung J, Zhu C, Esteller R, Saab CY. Time-dynamic pulse modulation of spinal cord stimulation reduces mechanical hypersensitivity and spontaneous pain in rats. Sci Rep 2020; 10:20358. [PMID: 33230202 PMCID: PMC7683561 DOI: 10.1038/s41598-020-77212-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/30/2020] [Indexed: 12/22/2022] Open
Abstract
Enhancing the efficacy of spinal cord stimulation (SCS) is needed to alleviate the burden of chronic pain and dependence on opioids. Present SCS therapies are characterized by the delivery of constant stimulation in the form of trains of tonic pulses (TPs). We tested the hypothesis that modulated SCS using novel time-dynamic pulses (TDPs) leads to improved analgesia and compared the effects of SCS using conventional TPs and a collection of TDPs in a rat model of neuropathic pain according to a longitudinal, double-blind, and crossover design. We tested the effects of the following SCS patterns on paw withdrawal threshold and resting state EEG theta power as a biomarker of spontaneous pain: Tonic (conventional), amplitude modulation, pulse width modulation, sinusoidal rate modulation, and stochastic rate modulation. Results demonstrated that under the parameter settings tested in this study, all tested patterns except pulse width modulation, significantly reversed mechanical hypersensitivity, with stochastic rate modulation achieving the highest efficacy, followed by the sinusoidal rate modulation. The anti-nociceptive effects of sinusoidal rate modulation on EEG outlasted SCS duration on the behavioral and EEG levels. These results suggest that TDP modulation may improve clinical outcomes by reducing pain intensity and possibly improving the sensory experience.
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Affiliation(s)
- Muhammad M Edhi
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA.,Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Lonne Heijmans
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA.,Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Kevin N Vanent
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA
| | - Kiernan Bloye
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA
| | - Amanda Baanante
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA
| | - Ki-Soo Jeong
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA.,Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jason Leung
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA.,Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Changfang Zhu
- Boston Scientific Neuromodulation, Valencia, CA, 91355, USA
| | | | - Carl Y Saab
- Department of Neurosurgery, Rhode Island Hospital, 593 Eddy St., Providence, RI, 02903, USA. .,Department of Neuroscience, Brown University, Providence, RI, 02903, USA. .,Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA. .,Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, 44195, USA. .,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA.
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25
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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: 51] [Impact Index Per Article: 12.8] [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.
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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
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26
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Mirzakhalili E, Barra B, Capogrosso M, Lempka SF. Biophysics of Temporal Interference Stimulation. Cell Syst 2020; 11:557-572.e5. [PMID: 33157010 DOI: 10.1016/j.cels.2020.10.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/21/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023]
Abstract
Temporal interference (TI) is a non-invasive neurostimulation technique that utilizes high-frequency external electric fields to stimulate deep neuronal structures without affecting superficial, off-target structures. TI represents a potential breakthrough for treating conditions, such as Parkinson's disease and chronic pain. However, early clinical work on TI stimulation was met with mixed outcomes challenging its fundamental mechanisms and applications. Here, we apply established physics to study the mechanisms of TI with the goal of optimizing it for clinical use. We argue that TI stimulation cannot work via passive membrane filtering, as previously hypothesized. Instead, TI stimulation requires an ion-channel mediated signal rectification process. Unfortunately, this mechanism is also responsible for high-frequency conduction block in off-target tissues, thus challenging clinical applications of TI. In consequence, we propose a set of experimental controls that should be performed in future experiments to refine our understanding and practice of TI stimulation. A record of this paper's transparent peer review process is included in the Supplemental Information.
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Affiliation(s)
- Ehsan Mirzakhalili
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Beatrice Barra
- Department of Neuroscience and Movement Science, University of Fribourg, Fribourg, Switzerland; Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Marco Capogrosso
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109, USA.
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27
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Hagedorn JM, Layno-Moses A, Sanders DT, Pak DJ, Bailey-Classen A, Sowder T. Overview of HF10 spinal cord stimulation for the treatment of chronic pain and an introduction to the Senza Omnia™ system. Pain Manag 2020; 10:367-376. [DOI: 10.2217/pmt-2020-0047] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Chronic intractable pain affects a significant percentage of the worldwide population, and it is one of the most disabling and expensive health conditions across the globe. Spinal cord stimulation (SCS) has been used to treat chronic pain for a number of years, but high-frequency SCS was not the US FDA approved until 2015. In this review, we describe the history and development of high-frequency SCS and discuss the benefits of the Omnia™ implantable pulse generator. We also provide a thorough literature review of the published work, highlighting the efficacy and safety profiles of high-frequency SCS for the treatment of multiple chronic pain conditions. Lastly, we offer our outlook on future developments with the Omnia SCS system.
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Affiliation(s)
- Jonathan M Hagedorn
- Department of Anesthesiology & Perioperative Medicine, Division of Pain Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Annie Layno-Moses
- Source Healthcare, 2801 Wilshire Blvd, Suite A, Santa Monica, CA 90403, USA
| | - Daniel T Sanders
- Spine Team Texas, 1120 Raintree Circle, Suite 110, Allen, TX 75013, USA
| | - Daniel J Pak
- Pain Medicine Division, New York-Presbyterian Hospital, Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, USA
| | | | - Timothy Sowder
- Department of Anesthesiology, Division of Pain Medicine, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, KS 66160, USA
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28
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Budde RB, Pederson DJ, Biggs EN, Jefferys JGR, Irazoqui PP. Mechanisms and prevention of acid reflux induced laryngospasm in seizing rats. Epilepsy Behav 2020; 111:107188. [PMID: 32540771 PMCID: PMC7541801 DOI: 10.1016/j.yebeh.2020.107188] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/04/2020] [Accepted: 05/23/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Recent animal work and limited clinical data have suggested that laryngospasm may be involved in the cardiorespiratory collapse seen in sudden unexpected death in epilepsy (SUDEP). In previous work, we demonstrated in an animal model of seizures that laryngospasm and sudden death were always preceded by acid reflux into the esophagus. Here, we expand on that work by testing several techniques to prevent the acid reflux or the subsequent laryngospasm. METHODS In urethane anesthetized Long Evans rats, we used systemic kainic acid to acutely induce seizure activity. We recorded pH in the esophagus, respiration, electrocorticography activity, and measured the liquid volume in the stomach postmortem. We performed the following three interventions to attempt to prevent acid reflux or laryngospasm and gain insights into mechanisms: fasting animals for 12 h, severing the gastric nerve, and electrical stimulation of either the gastric nerve or the recurrent laryngeal nerve. RESULTS Seizing animals had significantly more liquid in their stomach. Severing the gastric nerve and fasting animals significantly reduced stomach liquid volume, subsequent acid reflux, and sudden death. Laryngeal nerve stimulation can reverse laryngospasm on demand. Seizing animals are more susceptible to death from stomach acid-induced laryngospasm than nonseizing animals are to artificial acid-induced laryngospasm. SIGNIFICANCE These results provide insight into the mechanism of acid production and sudden obstructive apnea in this model. These techniques may have clinical relevance if this model is shown to be similar to human SUDEP.
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Affiliation(s)
- Ryan B. Budde
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Daniel J. Pederson
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Ethan N. Biggs
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - John G. R. Jefferys
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA,Department of Pharmacology, Oxford University, Oxford, UK,Department of Biochemistry, Oxford University, Oxford, UK
| | - Pedro P. Irazoqui
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA,Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
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29
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Peña E, Pelot NA, Grill WM. Quantitative comparisons of block thresholds and onset responses for charge-balanced kilohertz frequency waveforms. J Neural Eng 2020; 17:046048. [PMID: 32777778 DOI: 10.1088/1741-2552/abadb5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE There is growing interest in delivering kilohertz frequency (KHF) electrical signals to block conduction in peripheral nerves for treatment of various diseases. Previous studies used different KHF waveforms to achieve block, and it remains unclear how waveform affects nerve block parameters. APPROACH We quantified the effects of waveform on KHF block of the rat tibial nerve in vivo and in computational models. We compared block thresholds and onset responses across current-controlled sinusoids and charge-balanced rectangular waveforms with different asymmetries and duty cycles. MAIN RESULTS Sine waves had higher block thresholds than square waves, but used less power at block threshold. Block threshold had an inverse relationship with duty cycle of rectangular waveforms irrespective of waveform asymmetry. Computational model results were consistent with relationships measured in vivo, although the models underestimated the effect of duty cycle on increasing thresholds. The axonal membrane substantially filtered waveforms, the filter transfer function was strikingly similar across waveforms, and filtering resulted in post-filtered rms block thresholds that were approximately constant across waveforms in silico and in vivo. Onset response was not consistently affected by waveform shape, but onset response was smaller at amplitudes well above block threshold. Therefore, waveforms with lower block thresholds (e.g. sine waves or square waves) could be more readily increased to higher amplitudes relative to block threshold to reduce onset response. We also observed a reduction in onset responses across consecutive trials after initial application of supra-block threshold amplitudes. SIGNIFICANCE Waveform had substantial effects on block thresholds, and the amplitude relative to block threshold had substantial effects on onset response. These data inform choice of waveform in subsequent studies and clinical applications, enhance effective use of block in therapeutic applications, and facilitate the design of parameters that achieve block with minimal onset responses.
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Affiliation(s)
- Edgar Peña
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
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30
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Liao WT, Tseng CC, Chia WT, Lin CR. High-frequency spinal cord stimulation treatment attenuates the increase in spinal glutamate release and spinal miniature excitatory postsynaptic currents in rats with spared nerve injury-induced neuropathic pain. Brain Res Bull 2020; 164:307-313. [PMID: 32937185 DOI: 10.1016/j.brainresbull.2020.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/29/2020] [Accepted: 09/07/2020] [Indexed: 12/27/2022]
Abstract
High-frequency spinal cord stimulation (HFSCS) at 10 kHz provides paresthesia-free treatment for chronic pain. However, the underlying mechanisms of its action have not been fully elucidated. The aim of the present study was to investigate the effect of HFSCS treatment on spinal glutamate release and uptake in spared nerve injury (SNI) rats. HFSCS was applied to the T10/T11 spinal cord 3 days after SNI. The concentration of spinal glutamate, glutamate transporter activity and miniature excitatory postsynaptic currents (mEPSCs) from neurons in lamina II were evaluated. HFSCS treatment alleviated SNI pain induced by mechanical and cold allodynia. HFSCS treatment also partially restored altered spinal glutamate uptake activity, the levels of spinal glutamate, and the frequency of mEPSCs following SNI. In conclusion, HFSCS treatment attenuated SNI-induced neuropathic pain and partially restored the altered glutamate uptake after SNI.
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Affiliation(s)
- Wen-Tzu Liao
- Department of Anesthesiology, Chia-Yi Chang Gung Memorial Hospital, Chia-Yi, Taiwan
| | - Chia-Chih Tseng
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wan-Ting Chia
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chung-Ren Lin
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Anesthesiology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
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31
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Zander HJ, Graham RD, Anaya CJ, Lempka SF. Anatomical and technical factors affecting the neural response to epidural spinal cord stimulation. J Neural Eng 2020; 17:036019. [PMID: 32365340 PMCID: PMC8351789 DOI: 10.1088/1741-2552/ab8fc4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Spinal cord stimulation (SCS) is a common neurostimulation therapy to treat chronic pain. Computational models represent a valuable tool to study the potential mechanisms of action of SCS and to optimize the design and implementation of SCS technologies. However, it is imperative that these computational models include the appropriate level of detail to accurately predict the neural response to SCS and to correlate model predictions with clinical outcomes. Therefore, the goal of this study was to investigate several anatomic and technical factors that may affect model-based predictions of neural activation during thoracic SCS. APPROACH We developed computational models that consisted of detailed finite element models of the lower thoracic spinal cord, surrounding tissues, and implanted SCS electrode arrays. We positioned multicompartment models of sensory axons within the spinal cord to calculate the activation threshold for each sensory axon. We then investigated how activation thresholds changed as a function of several anatomical variables (e.g. spine geometry, dorsal rootlet anatomy), stimulation type (i.e. voltage-controlled vs. current-controlled), electrode impedance, lead position, lead type, and electrical properties of surrounding tissues (e.g. dura conductivity, frequency-dependent conductivity). MAIN RESULTS Several anatomic and modeling factors produced significant percent differences or errors in activation thresholds. Rostrocaudal positioning of the cathode with respect to the vertebrae had a large effect (up to 32%) on activation thresholds. Variability in electrode impedance produced significant changes in activation thresholds for voltage-controlled stimulation (38% to 51%), but had little effect on activation thresholds for current-controlled stimulation (less than 13%). Changing the dura conductivity also produced significant differences in activation thresholds. SIGNIFICANCE This study demonstrates several anatomic and technical factors that can affect the neural response to SCS. These factors should be considered in clinical implementation and in future computational modeling studies of thoracic SCS.
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Affiliation(s)
- Hans J Zander
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America. Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
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32
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Jiang L, Zhang N, Zhang S, Chen JD. Sacral nerve stimulation with optimized parameters improves visceral hypersensitivity in rats mediated via the autonomic pathway. Mol Pain 2020; 15:1744806919880651. [PMID: 31530213 PMCID: PMC6775554 DOI: 10.1177/1744806919880651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The purpose of this study was to determine effects and mechanisms of sacral nerve stimulation (SNS) on visceral hypersensitivity in rodent models of colonic hypersensitivity. SNS was performed with different sets of parameters for 30 min in six regular rats. Visceral sensitivity was assessed by the measurement of electromyogram and abdominal withdrawal reflex before and after SNS. Real/sham SNS with optimized parameters was performed in 8 restraint stress-induced visceral hypersensitivity rats and 10 neonatal acetic acid-treated colonic hypersensitivity rats; acute effect of SNS was assessed by comparing electromyogram and heart rate variability. Neonatal acetic acid-treated rats were treated by SNS (n = 10) or sham-SNS (n = 10) daily for seven days for the assessment of the chronic effect of SNS. (1) When the stimulation amplitude was reduced from 90% of motor threshold to 65% or 40% motor threshold, SNS with certain parameters showed an inhibitory effect on abdominal withdrawal reflex. The best stimulation parameters for SNS were “14 Hz, 330 µs, and 40% motor threshold.” (2) SNS significantly reduced visceral hypersensitivity and improved autonomic function in restraint stress-induced rats. The inhibitory effect was blocked by naloxone. (3)Acute and chronic SNS significantly reduced visceral hypersensitivity and improved autonomic function in acetic acid-treated rats. SNS with reduced stimulation strength may be used to treat colonic hypersensitivity and the best stimulation parameters seem to be “14 Hz, 330 µs and 40% motor threshold”. SNS with optimized parameters improved visceral hypersensitivity in rodent models of colonic hypersensitivity mediated via the autonomic and opioid mechanisms.
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Affiliation(s)
- Liuqin Jiang
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Nina Zhang
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shengai Zhang
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiande Dz Chen
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Fishman MA, Antony A, Esposito M, Deer T, Levy R. The Evolution of Neuromodulation in the Treatment of Chronic Pain: Forward-Looking Perspectives. PAIN MEDICINE 2020; 20:S58-S68. [PMID: 31152176 PMCID: PMC6600066 DOI: 10.1093/pm/pnz074] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background The field of neuromodulation is continually evolving, with the past decade showing significant advancement in the therapeutic efficacy of neuromodulation procedures. The continued evolution of neuromodulation technology brings with it the promise of addressing the needs of both patients and physicians, as current technology improves and clinical applications expand. Design This review highlights the current state of the art of neuromodulation for treating chronic pain, describes key areas of development including stimulation patterns and neural targets, expanding indications and applications, feedback-controlled systems, noninvasive approaches, and biomarkers for neuromodulation and technology miniaturization. Results and Conclusions The field of neuromodulation is undergoing a renaissance of technology development with potential for profoundly improving the care of chronic pain patients. New and emerging targets like the dorsal root ganglion, as well as high-frequency and patterned stimulation methodologies such as burst stimulation, are paving the way for better clinical outcomes. As we look forward to the future, neural sensing, novel target-specific stimulation patterns, and approaches combining neuromodulation therapies are likely to significantly impact how neuromodulation is used. Moreover, select biomarkers may influence and guide the use of neuromodulation and help objectively demonstrate efficacy and outcomes.
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Affiliation(s)
| | | | | | - Timothy Deer
- The Spine and Nerve Center of the Virginias, Charleston, West Virginia
| | - Robert Levy
- Institute for Neuromodulation, Boca Raton, Florida, USA
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Pelot NA, Grill WM. In vivo quantification of excitation and kilohertz frequency block of the rat vagus nerve. J Neural Eng 2020; 17:026005. [PMID: 31945746 DOI: 10.1088/1741-2552/ab6cb6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE There is growing interest in treating diseases by electrical stimulation and block of peripheral autonomic nerves, but a paucity of studies on the excitation and block of small-diameter autonomic axons. We conducted in vivo quantification of the strength-duration properties, activity-dependent slowing (ADS), and responses to kilohertz frequency (KHF) signals for the rat vagus nerve (VN). APPROACH We conducted acute in vivo experiments in urethane-anaesthetized rats. We placed two cuff electrodes on the left cervical VN and one cuff electrode on the anterior subdiaphragmatic VN. The rostral cervical cuff was used to deliver pulses to quantify recruitment and ADS. The caudal cervical cuff was used to deliver KHF signals. The subdiaphragmatic cuff was used to record compound action potentials (CAPs). MAIN RESULTS We quantified the input-output recruitment and strength-duration curves. Fits to the data using standard strength-duration equations were qualitatively similar, but the resulting chronaxie and rheobase estimates varied substantially. We measured larger thresholds for the slowest fibres (0.5-1 m s-1), especially at shorter pulse widths. Using a novel cross-correlation CAP-based analysis, we measured ADS of ~2.3% after 3 min of 2 Hz stimulation, which is comparable to the ADS reported for sympathetic efferents in somatic nerves, but much smaller than the ADS in cutaneous nociceptors. We found greater ADS with higher stimulation frequency and non-monotonic changes in CV in select cases. We found monotonically increasing block thresholds across frequencies from 10 to 80 kHz for both fast and slow fibres. Further, following 25 s of KHF signal, neural conduction could require tens of seconds to recover. SIGNIFICANCE The quantification of mammalian autonomic nerve responses to conventional and KHF signals provides essential information for the development of peripheral nerve stimulation therapies and for understanding their mechanisms of action.
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Affiliation(s)
- N A Pelot
- Department of Biomedical Engineering, Duke University, Room 1427, Fitzpatrick CIEMAS, 101 Science Drive, Campus Box 90281, Durham, NC 27708, United States of America
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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.
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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
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Lee KY, Bae C, Lee D, Kagan Z, Bradley K, Chung JM, La JH. Low-intensity, Kilohertz Frequency Spinal Cord Stimulation Differently Affects Excitatory and Inhibitory Neurons in the Rodent Superficial Dorsal Horn. Neuroscience 2020; 428:132-139. [PMID: 31917342 DOI: 10.1016/j.neuroscience.2019.12.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/26/2019] [Accepted: 12/18/2019] [Indexed: 12/31/2022]
Abstract
Since 1967, spinal cord stimulation (SCS) has been used to manage chronic intractable pain of the trunk and limbs. Compared to traditional high-intensity, low-frequency (<100 Hz) SCS that is thought to produce paresthesia and pain relief by stimulating large myelinated fibers in the dorsal column (DC), low-intensity, high-frequency (10 kHz) SCS has demonstrated long-term pain relief without generation of paresthesia. To understand this paresthesia-free analgesic mechanism of 10 kHz SCS, we examined whether 10 kHz SCS at intensities below sensory thresholds would modulate spinal dorsal horn (DH) neuronal function in a neuron type-dependent manner. By using in vivo and ex vivo electrophysiological approaches, we found that low-intensity (sub-sensory threshold) 10 kHz SCS, but not 1 kHz or 5 kHz SCS, selectively activates inhibitory interneurons in the spinal DH. This study suggests that low-intensity 10 kHz SCS may inhibit pain sensory processing in the spinal DH by activating inhibitory interneurons without activating DC fibers, resulting in paresthesia-free pain relief.
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Affiliation(s)
| | - Chilman Bae
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | | | | | | | - Jin Mo Chung
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Jun-Ho La
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, USA.
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Arle JE, Mei L, Carlson KW. Fiber Threshold Accommodation as a Mechanism of Burst and High-Frequency Spinal Cord Stimulation. Neuromodulation 2019; 23:582-593. [PMID: 31774232 DOI: 10.1111/ner.13076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/06/2019] [Accepted: 10/17/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Burst and high-frequency spinal cord stimulation (SCS), in contrast to low-frequency stimulation (LFS, < 200 Hz), reduce neuropathic pain without the side effect of paresthesia, yet it is unknown whether these methods' mechanisms of action (MoA) overlap. We used empirically based computational models of fiber threshold accommodation to examine the three MoA. MATERIALS AND METHODS Waveforms used in SCS are composed of cathodic, anodic, and rest phases. Empirical studies of human peripheral sensory nerve fibers show different accommodation effects occurring in each phase. Notably, larger diameter fibers accommodate more than smaller fibers. We augmented our computational axon model to replicate fiber threshold accommodation behavior for diameters from 5 to 15 μm in each phase. We used the model to predict threshold change in variations of burst, high frequency, and LFS. RESULTS The accommodation model showed that 1) inversion of larger and smaller diameter fiber thresholds produce a therapeutic window in which smaller fibers fire while larger ones do not and 2) the anodic pulses increase accommodation and perpetuate threshold inversion from burst to burst and between cathodic pulses in burst, high frequency, and variations, resulting in an amplitude "window" in which larger fibers are inactivated while smaller fibers fire. No threshold inversion was found for traditional LFS. CONCLUSIONS The model, based on empirical data, predicts that, at clinical amplitudes, burst and high-frequency SCS do not activate large-diameter fibers that produce paresthesia while driving medium-diameter fibers, likely different from LFS, which produce analgesia via different populations of dorsal horn neural circuits.
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Affiliation(s)
- Jeffrey E Arle
- Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Department of Neurosurgery, Harvard Medical School, Boston, MA, USA.,Department of Neurosurgery, Mount Auburn Hospital, Cambridge, MA, USA
| | - Longzhi Mei
- Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Kristen W Carlson
- Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
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38
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Ratnayake CB, Bunn A, Pandanaboyana S, Windsor JA. Spinal Cord Stimulation for Management of Pain in Chronic Pancreatitis: A Systematic Review of Efficacy and Complications. Neuromodulation 2019; 23:19-25. [DOI: 10.1111/ner.13051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/11/2019] [Accepted: 08/20/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Chathura Bathiya Ratnayake
- Department of Surgery, School of Medicine, Faculty of Medical and Health SciencesUniversity of Auckland Auckland New Zealand
- HPB/Upper GI Unit, Department of General SurgeryAuckland City Hospital Auckland New Zealand
| | - Amanda Bunn
- Department of Surgery, School of Medicine, Faculty of Medical and Health SciencesUniversity of Auckland Auckland New Zealand
- HPB/Upper GI Unit, Department of General SurgeryAuckland City Hospital Auckland New Zealand
| | | | - John Albert Windsor
- Department of Surgery, School of Medicine, Faculty of Medical and Health SciencesUniversity of Auckland Auckland New Zealand
- HPB/Upper GI Unit, Department of General SurgeryAuckland City Hospital Auckland New Zealand
- Surgical and Translational Research Centre, Faculty of Medical and Health SciencesUniversity of Auckland Auckland New Zealand
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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: 13] [Impact Index Per Article: 2.6] [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.
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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.
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40
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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: 105] [Impact Index Per Article: 21.0] [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.
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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
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De Groote S, Goudman L, Peeters R, Linderoth B, Vanschuerbeek P, Sunaert S, De Jaeger M, De Smedt A, Moens M. Magnetic Resonance Imaging Exploration of the Human Brain During 10 kHz Spinal Cord Stimulation for Failed Back Surgery Syndrome: A Resting State Functional Magnetic Resonance Imaging Study. Neuromodulation 2019; 23:46-55. [PMID: 30974016 DOI: 10.1111/ner.12954] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/08/2019] [Accepted: 02/27/2019] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Apart from the clinical efficacy of high frequency spinal cord stimulation at 10 kHz, the underlying mechanism of action remains unclear. In parallel with spinal or segmental theories, supraspinal hypotheses have been recently proposed. In order to unveil hidden altered brain connectome patterns, a resting state functional magnetic resonance imaging (rsfMRI) protocol was performed in subjects routinely treated for back and/or leg pain with high-frequency spinal cord stimulation (HF-SCS) HF-SCS at 10 kHz. METHODS RsfMRI imaging was obtained from ten patients with failed back surgery syndrome who were eligible for HF-SCS at 10 kHz. Specifically-chosen regions of interest with different connectivity networks have been investigated over time. Baseline measurements were compared with measurements after 1 month and 3 months of HF-SCS at 10 kHz. Additionally, clinical parameters on pain intensity, central sensitization, pain catastrophizing, and sleep quality were correlated with the functional connectivity strengths. RESULTS The study results demonstrate an increased connectivity over time between the anterior insula (affective salience network) and regions of the frontoparietal network and the central executive network. After 3 months of HF-SCS, the increased strength in functional connectivity between the left dorsolateral prefrontal cortex and the right anterior insula was significantly correlated with the minimum clinically important difference (MCID) value of the Pittsburgh sleep quality index. CONCLUSION These findings support the hypothesis that HF-SCS at 10 kHz might influence the salience network and therefore also the emotional awareness of pain.
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Affiliation(s)
- Sander De Groote
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Lisa Goudman
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Brussels, Belgium.,Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussel, Belgium
| | - Ronald Peeters
- Department of Radiology, Universitair Ziekenhuis Leuven, UZ, Leuven, Belgium
| | - Bengt Linderoth
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | - Stefan Sunaert
- Department of Radiology, Universitair Ziekenhuis Leuven, UZ, Leuven, Belgium
| | - Mats De Jaeger
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Ann De Smedt
- Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Maarten Moens
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Brussels, Belgium.,Department of Radiology, Universitair Ziekenhuis Brussel, Brussels, Belgium.,Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
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Sivanesan E, Maher D, Raja SN, Linderoth B, Guan Y. Supraspinal Mechanisms of Spinal Cord Stimulation for Modulation of Pain: Five Decades of Research and Prospects for the Future. Anesthesiology 2019; 130:651-665. [PMID: 30556812 PMCID: PMC6338535 DOI: 10.1097/aln.0000000000002353] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The field of spinal cord stimulation is expanding rapidly, with new waveform paradigms asserting supraspinal sites of action. The scope of treatment applications is also broadening from chronic pain to include cerebral ischemia, dystonia, tremor, multiple sclerosis, Parkinson disease, neuropsychiatric disorders, memory, addiction, cognitive function, and other neurologic diseases. The role of neurostimulation as an alternative strategy to opioids for chronic pain treatment is under robust discussion in both scientific and public forums. An understanding of the supraspinal mechanisms underlying the beneficial effects of spinal cord stimulation will aid in the appropriate application and development of optimal stimulation strategies for modulating pain signaling pathways. In this review, the authors focus on clinical and preclinical studies that indicate the role of supraspinal mechanisms in spinal cord stimulation-induced pain inhibition, and explore directions for future investigations.
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Affiliation(s)
- Eellan Sivanesan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Dermot Maher
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Srinivasa N. Raja
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Bengt Linderoth
- Department of Clinical Neuroscience, Karolinska Institutet, Tomtebodavägen 18A:05, SE 171 77 Stockholm, Sweden
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
- Department of Neurological Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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43
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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.
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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
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Roldan LM, Eggers TE, Kilgore KL, Bhadra N, Vrabec T, Bhadra N. Measurement of block thresholds in kiloHertz frequency alternating current peripheral nerve block. J Neurosci Methods 2019; 315:48-54. [PMID: 30641091 PMCID: PMC6380354 DOI: 10.1016/j.jneumeth.2019.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/21/2018] [Accepted: 01/10/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUND Kilohertz frequency alternating currents (KHFAC) produce rapid nerve conduction block of mammalian peripheral nerve and have potential clinical applications in reducing peripheral nerve hyperactivity. The experimental investigation of KHFAC nerve block requires a robust output measure and this has proven to be the block threshold (BT), the lowest current or voltage at which the axons of interest are completely blocked. All significant literature in KHFAC nerve block, both simulations and experimental, were reviewed to determine the block threshold method that was used. The two common methods used are the High-Low method experimentally and the Binary search method for simulations. NEW METHOD Four methods to measure the block threshold (High-Low, High-Low-High, Binary and Random) at three frequencies (10, 20 and 30 kHz) were compared through randomized repeated experiments in the in-vivo rodent sciatic nerve-gastrocnemius model. RESULTS The literature review showed that more than 50% of publications did not measure the block threshold. The experimental results showed no statistical difference in the BT value between the four methods. COMPARISON WITH EXISTING METHOD(S) However, there were differences in the number of significant onset responses, depending on the method. The run time for the BT determination was the shortest for the High-Low method. CONCLUSIONS It is recommended that all research in electrical nerve block, including KHFAC, should include measurement of the BT. The High-Low method is recommended for most experimental situations but the Binary method could also be a viable option, especially where onset responses are minimal.
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Affiliation(s)
- Leah Marie Roldan
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Thomas E Eggers
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Kevin L Kilgore
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA; MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, 44109, USA; Louis Stokes VA Medical Center, 10701 East Boulevard, Cleveland, OH, 44106, USA
| | - Narendra Bhadra
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Tina Vrabec
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Niloy Bhadra
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA; MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, 44109, USA.
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Spinal Cord Stimulation for Pain Treatment After Spinal Cord Injury. Neurosci Bull 2018; 35:527-539. [PMID: 30560438 DOI: 10.1007/s12264-018-0320-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/11/2018] [Indexed: 12/30/2022] Open
Abstract
In addition to restoration of bladder, bowel, and motor functions, alleviating the accompanying debilitating pain is equally important for improving the quality of life of patients with spinal cord injury (SCI). Currently, however, the treatment of chronic pain after SCI remains a largely unmet need. Electrical spinal cord stimulation (SCS) has been used to manage a variety of chronic pain conditions that are refractory to pharmacotherapy. Yet, its efficacy, benefit profiles, and mechanisms of action in SCI pain remain elusive, due to limited research, methodological weaknesses in previous clinical studies, and a lack of mechanistic exploration of SCS for SCI pain control. We aim to review recent studies and outline the therapeutic potential of different SCS paradigms for traumatic SCI pain. We begin with an overview of its manifestations, classification, potential underlying etiology, and current challenges for its treatment. The clinical evidence for using SCS in SCI pain is then reviewed. Finally, future perspectives of pre-clinical research and clinical study of SCS for SCI pain treatment are discussed.
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Duse G, Reverberi C, Dario A. Effects of Multiple Waveforms on Patient Preferences and Clinical Outcomes in Patients Treated With Spinal Cord Stimulation for Leg and/or Back Pain. Neuromodulation 2018; 22:200-207. [PMID: 30548106 DOI: 10.1111/ner.12899] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/07/2018] [Accepted: 10/23/2018] [Indexed: 01/19/2023]
Abstract
OBJECTIVES We present the results of a prospective, randomized, crossover, single-blind, study in which each patient is in control of himself. The aim was to evaluate subperception-based (SP-SCS) waveforms in previously implanted spinal cord stimulation (SCS) patients with leg and/or back pain due to failed back surgery syndrome, who experienced only paresthesia-based stimulation (PB-SCS). Patients with PB-SCS experience in SCS was 4.7 years (SD 2.9). MATERIALS AND METHODS We enrolled 28 consecutive patients. Treatment consisted of seven days of PB-SCS, followed by a randomized, crossover phase to test SP-SCS waveforms (burst or 1 kHz frequency, seven days each). A maximum of three-day washout period separated each stimulation program. RESULTS Statistically significant pain relief was maintained using both SP-SCS waveforms, as indicated by the differences between the pre-PB-SCS numeric pain rating score (mean 9) and the pain score after using the burst program (pain relief 52%) or the 1 kHz program (pain relief 51%). There was no statistically significant superiority among PB-SCS, burst, and 1 kHz stimulation. Overall, 50% of patients preferred PB-SCS, 42% chose to move to SP-SCS stimulation, one patient was unable to give feedback, and one patient was unsuccessful with any type of stimulation. Overall, SCS has shown to be successful in pain relief and the patients switched to a SP-SCS waveform only for having higher pain relief. CONCLUSIONS There was a high heterogeneity regarding waveform preference, with patients who preferred to feel the tingling sensation and those who chose a SP-SCS option, mainly for greater pain relief. In general, SCS is successful, resulting in high pain relief, improvements in quality of life, and little depression. Overall, 42% patients benefited from the novel SP-SCS stimulation waveforms.
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Affiliation(s)
- Genni Duse
- Pain Unit, Padova Regional Hospital, Padova, Italy
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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.
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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
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Loeb GE. Neural Prosthetics:A Review of Empirical vs. Systems Engineering Strategies. Appl Bionics Biomech 2018; 2018:1435030. [PMID: 30532801 PMCID: PMC6247642 DOI: 10.1155/2018/1435030] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/28/2018] [Accepted: 08/05/2018] [Indexed: 12/21/2022] Open
Abstract
Implantable electrical interfaces with the nervous system were first enabled by cardiac pacemaker technology over 50 years ago and have since diverged into almost all of the physiological functions controlled by the nervous system. There have been a few major clinical and commercial successes, many contentious claims, and some outright failures. These tend to be reviewed within each clinical subspecialty, obscuring the many commonalities of neural control, biophysics, interface materials, electronic technologies, and medical device regulation that they share. This review cites a selection of foundational and recent journal articles and reviews for all major applications of neural prosthetic interfaces in clinical use, trials, or development. The hard-won knowledge and experience across all of these fields can now be amalgamated and distilled into more systematic processes for development of clinical products instead of the often empirical (trial and error) approaches to date. These include a frank assessment of a specific clinical problem, the state of its underlying science, the identification of feasible targets, the availability of suitable technologies, and the path to regulatory and reimbursement approval. Increasing commercial interest and investment facilitates this systematic approach, but it also motivates projects and products whose claims are dubious.
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Affiliation(s)
- Gerald E. Loeb
- Professor of Biomedical Engineering, University of Southern California, 1042 Downey Way (DRB-B11) Los Angeles, CA 90089, USA
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Zannou AL, Khadka N, Truong DQ, Zhang T, Esteller R, Hershey B, Bikson M. Temperature increases by kilohertz frequency spinal cord stimulation. Brain Stimul 2018; 12:62-72. [PMID: 30482674 DOI: 10.1016/j.brs.2018.10.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Kilohertz frequency spinal cord stimulation (kHz-SCS) deposits significantly more power in tissue compared to SCS at conventional frequencies, reflecting increased duty cycle (pulse compression). We hypothesize kHz-SCS increases local tissue temperature by joule heat, which may influence the clinical outcomes. METHODS To establish the role of tissue heating in KHZ-SCS, a decisive first step is to characterize the range of temperature changes expected during conventional and KHZ-SCS protocols. Fiber optic probes quantified temperature increases around an experimental SCS lead in a bath phantom. These data were used to verify a SCS lead heat-transfer model based on joule heat. Temperature increases were then predicted in a seven-compartment (soft tissue, vertebral bone, fat, intervertebral disc, meninges, spinal cord with nerve roots) geometric human spinal cord model under varied parameterization. RESULTS The experimentally constrained bio-heat model shows SCS waveform power (waveform RMS) determines tissue heating at the spinal cord and surrounding tissues. For example, we predict temperature increased at dorsal spinal cord of 0.18-1.72 °C during 3.5 mA peak 10 KHz stimulation with a 40-10-40 μs biphasic pulse pattern, 0.09-0.22 °C during 3.5 mA 1 KHz 100-100-100 μs stimulation, and less than 0.05 °C during 3.5 mA 50 Hz 200-100-200 μs stimulation. Notably, peak heating of the spinal cord and other tissues increases superlinearly with stimulation power and so are especially sensitive to incremental changes in SCS pulse amplitude or frequency (with associated pulse compression). Further supporting distinct SCS intervention strategies based on heating; the spatial profile of temperature changes is more uniform compared to electric fields, which suggests less sensitivity to lead position. CONCLUSIONS Tissue heating may impact short and long-term outcomes of KHZ-SCS, and even as an adjunct mechanism, suggests distinct strategies for lead position and programming optimization.
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Affiliation(s)
- Adantchede L Zannou
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA
| | - Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA
| | - Dennis Q Truong
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA
| | - Tianhe Zhang
- Boston Scientific Inc., Neuromodulation Research and Advanced Concepts, Valencia, CA, USA
| | - Rosana Esteller
- Boston Scientific Inc., Neuromodulation Research and Advanced Concepts, Valencia, CA, USA
| | - Brad Hershey
- Boston Scientific Inc., Neuromodulation Research and Advanced Concepts, Valencia, CA, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, 10031, USA.
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Grill WM. Temporal Pattern of Electrical Stimulation is a New Dimension of Therapeutic Innovation. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2018; 8:1-6. [PMID: 30906909 DOI: 10.1016/j.cobme.2018.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Artificial activation of the nervous system requires selection of appropriate stimulation parameters including stimulation amplitude, stimulation pulse duration, and stimulation pulse repetition rate. The temporal pattern of stimulation, i.e., the timing between stimulation pulses, is a novel dimension of stimulation parameter tuning. The effects evoked by artificial activation of the nervous system are dependent on the pattern of stimulation, and different patterns of stimulation, even when delivered at the same average rate, evoke different functional effects, different changes in synaptic plasticity, and even different patterns of gene expression. Non-regular temporal patterns of stimulation offer the opportunity to improve the efficacy and efficiency of therapeutic stimulation as well as to manipulate other processes in the nervous system. The potential design space for sequences of varying interpulse intervals is exceedingly large and sound approaches to design stimulation patterns are required as an empirical approach is not practical.
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Affiliation(s)
- Warren M Grill
- Departments of Biomedical Engineering, Electrical and Computer Engineering, Neurobiology, and Neurosurgery, Duke University, Durham NC
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