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Levett JJ, Elkaim LM, Niazi F, Weber MH, Iorio-Morin C, Bonizzato M, Weil AG. Invasive Brain Computer Interface for Motor Restoration in Spinal Cord Injury: A Systematic Review. Neuromodulation 2024; 27:597-603. [PMID: 37943244 DOI: 10.1016/j.neurom.2023.10.006] [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: 06/12/2023] [Revised: 09/10/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023]
Abstract
STUDY DESIGN Systematic review of the literature. OBJECTIVES In recent years, brain-computer interface (BCI) has emerged as a potential treatment for patients with spinal cord injury (SCI). This is the first systematic review of the literature on invasive closed-loop BCI technologies for the treatment of SCI in humans. MATERIALS AND METHODS A comprehensive search of PubMed MEDLINE, Web of Science, and Ovid EMBASE was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS Of 8316 articles collected, 19 studies met all the inclusion criteria. Data from 21 patients were extracted from these studies. All patients sustained a cervical SCI and were treated using either a BCI with intracortical microelectrode arrays (n = 18, 85.7%) or electrocorticography (n = 3, 14.3%). To decode these neural signals, machine learning and statistical models were used: support vector machine in eight patients (38.1%), linear estimator in seven patients (33.3%), Hidden Markov Model in three patients (14.3%), and other in three patients (14.3%). As the outputs, ten patients (47.6%) underwent noninvasive functional electrical stimulation (FES) with a cuff; one (4.8%) had an invasive FES with percutaneous stimulation, and ten (47.6%) used an external device (neuroprosthesis or virtual avatar). Motor function was restored in all patients for each assigned task. Clinical outcome measures were heterogeneous across all studies. CONCLUSIONS Invasive techniques of BCI show promise for the treatment of SCI, but there is currently no technology that can restore complete functional autonomy in patients with SCI. The current techniques and outcomes of BCI vary greatly. Because invasive BCIs are still in the early stages of development, further clinical studies should be conducted to optimize the prognosis for patients with SCI.
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Affiliation(s)
- Jordan J Levett
- Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Lior M Elkaim
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Farbod Niazi
- Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Michael H Weber
- Department of Orthopaedic Surgery, McGill University, Montreal, Quebec, Canada
| | | | - Marco Bonizzato
- Department of Electrical Engineering and Institute of Biomedical Engineering, Polytechnique Montréal, Montreal, Quebec, Canada; Department of Neuroscience and Centre interdisciplinaire sur le cerveau et l'apprentissage, University of Montreal, Montreal, Quebec, Canada
| | - Alexander G Weil
- Division of Neurosurgery, St-Justine University Hospital, Montreal, Quebec, Canada.
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Spinal Cord Stimulation in Chronic Low Back Pain Syndrome: Mechanisms of Modulation, Technical Features and Clinical Application. Healthcare (Basel) 2022; 10:healthcare10101953. [PMID: 36292400 PMCID: PMC9601444 DOI: 10.3390/healthcare10101953] [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: 09/14/2022] [Revised: 09/29/2022] [Accepted: 10/04/2022] [Indexed: 11/04/2022] Open
Abstract
Chronic low-back pain (CLBP) is a common disease with several negative consequences on the quality of life, work and activity ability and increased costs to the health-care system. When pharmacological, psychological, physical and occupational therapies or surgery fail to reduce CLBP, patients may be a candidate for Spinal Cord Stimulation (SCS). SCS consists of the transcutaneous or surgical implantation of different types of electrodes in the epidural space; electrodes are then connected to an Implanted Pulse Generator (IPG) that generates stimulating currents. Through spinal and supraspinal mechanisms based on the “gate control theory for pain transmission”, SCS reduces symptoms of CLBP in the almost totality of well-selected patients and its effect lasts up to eight years in around 75% of patients. However, the evidence in favor of SCS still remains weak, mainly due to poor trial methodology and design. This narrative review is mainly addressed to those professionals that may encounter patients with CLBP failing conventional treatments. For this reason, we report the mechanisms of pain relief during SCS, the technical features and some clinical considerations about the application of SCS in patients with CLBP.
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Tapia Pérez JH. Spinal cord stimulation: Beyond pain management. Neurologia 2022; 37:586-595. [PMID: 31337556 DOI: 10.1016/j.nrl.2019.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 05/03/2019] [Accepted: 05/20/2019] [Indexed: 02/04/2023] Open
Abstract
INTRODUCTION The gate control theory of pain was the starting point of the development of spinal cord stimulation (SCS). We describe the indications for the treatment in pain management and other uses not related to pain. DEVELOPMENT There are currently several paradigms for SCS: tonic, burst, and high frequency. The main difference lies in the presence of paraesthesias. SCS is most beneficial for treating neuropathic pain. Patients with failed back surgery syndrome show the best response rates, although a considerable reduction in pain is also observed in patients with complex regional pain syndrome, diabetic neuropathy, radiculopathy, and low back pain without previous surgery. Phantom pain or pain related to cardiovascular or peripheral vascular disease may improve, although there is a lack of robust evidence supporting generalisation of its use. SCS also improves cancer-related pain, although research on this issue is scarce. Non-pain-related indications for SCS are movement disorders, spasticity, and sequelae of spinal cord injury. The main limiting factors for the use of SCS are mechanical complications and the cost of the treatment. CONCLUSION In its 50-year history, SCS has progressed enormously. The perfection of hardware and software may improve its effectiveness and reduce the rate of complications. Indications for SCS could include other diseases, and its use could be expanded, if the costs of the technology are reduced.
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Affiliation(s)
- J H Tapia Pérez
- Department of Spine Surgery, Leopoldina-Krankenhaus der Stadt Schweinfurt, Schweinfurt, Alemania.
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Kandhari S, Sharma D, Samuel S, Sharma G, Majumdar P, Edgerton VR, Gad P. Epidural spinal stimulation enables global sensorimotor and autonomic function recovery after complete paralysis: 1st study from India. IEEE Trans Neural Syst Rehabil Eng 2022; 30:2052-2059. [PMID: 35271446 DOI: 10.1109/tnsre.2022.3158393] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
While the loss of sensorimotor and autonomic function often occurs due to multiple trauma and pathologies, spinal cord injury is one of the few traumatic pathologies that severely affects multiple organ systems both upstream and downstream of the injury. Current standard of care therapies primarily maintains health and avoids secondary complications. They do not address the underlying neurological condition. Multiple modalities including spinal neuromodulation have shown promise as potential therapies. The objective of this study was to demonstrate the impact of activity-based neurorehabilitation in presence of epidural spinal stimulation to enable simultaneous global recovery of sensorimotor and autonomic functions in patients with complete motor paralysis due to spinal cord injury. These data are unique in that it quantifies simultaneously changes multiple organ systems within only 2 months of intense activity-based neurorehabilitation when also delivering epidural stimulation consisting of sub-motor threshold stimulation over a period of 12-16 hours/day to enable 'self-training' in 10 patients. Finally, these studies were done in a traditional neurorehabilitation clinical in India using off-the-shelf electrode arrays and pulse generators, thus demonstrating the feasibility of this approach in simultaneously enabling recoveries of multiple physiological organ systems after chronic paralysis and the ability to perform these procedures in a standard, well-controlled clinical environment.
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Thakre PP, Sunshine MD, Fuller DD. Spinally delivered ampakine CX717 increases phrenic motor output in adult rats. Respir Physiol Neurobiol 2022; 296:103814. [PMID: 34775071 PMCID: PMC9235873 DOI: 10.1016/j.resp.2021.103814] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/01/2021] [Accepted: 11/07/2021] [Indexed: 02/03/2023]
Abstract
Ampakines are synthetic molecules that allosterically modulate AMPA-type glutamate receptors. We tested the hypothesis that delivery of ampakines to the intrathecal space could stimulate neural drive to the diaphragm. Ampakine CX717 (20 mM, dissolved in 10 % HPCD) or an HPCD vehicle solution were delivered via a catheter placed in the intrathecal space at the fourth cervical segment in urethane-anesthetized, mechanically ventilated adult male Sprague-Dawley rats. The electrical activity of the phrenic nerve was recorded for 60-minutes following drug application. Intrathecal application of CX717 produced a gradual and sustained increase in phrenic inspiratory burst amplitude (n = 10). In contrast, application of HPCD (n = 10) caused no sustained change in phrenic motor output. Phrenic burst rate, heart rate, and mean arterial pressure were similar between CX717 and HPCD treated rats. We conclude that intrathecally delivered ampakines can modulate phrenic motor output. This approach may have value for targeted induction of spinal neuroplasticity in the context of neurorehabiliation.
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Affiliation(s)
- Prajwal P. Thakre
- Department of Physical Therapy, University of Florida, Gainesville, FL,Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL,McKnight Brain Institute, University of Florida, Gainesville, FL
| | - Michael D. Sunshine
- Department of Physical Therapy, University of Florida, Gainesville, FL,Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL,McKnight Brain Institute, University of Florida, Gainesville, FL
| | - David D. Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL,Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL,McKnight Brain Institute, University of Florida, Gainesville, FL,Corresponding author: David D. Fuller, Department of Physical Therapy, University of Florida, 1149 Newell Drive, Gainesville, FL 32611
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Lubejko ST, Graham RD, Livrizzi G, Schaefer R, Banghart MR, Creed MC. The role of endogenous opioid neuropeptides in neurostimulation-driven analgesia. Front Syst Neurosci 2022; 16:1044686. [PMID: 36591324 PMCID: PMC9794630 DOI: 10.3389/fnsys.2022.1044686] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022] Open
Abstract
Due to the prevalence of chronic pain worldwide, there is an urgent need to improve pain management strategies. While opioid drugs have long been used to treat chronic pain, their use is severely limited by adverse effects and abuse liability. Neurostimulation techniques have emerged as a promising option for chronic pain that is refractory to other treatments. While different neurostimulation strategies have been applied to many neural structures implicated in pain processing, there is variability in efficacy between patients, underscoring the need to optimize neurostimulation techniques for use in pain management. This optimization requires a deeper understanding of the mechanisms underlying neurostimulation-induced pain relief. Here, we discuss the most commonly used neurostimulation techniques for treating chronic pain. We present evidence that neurostimulation-induced analgesia is in part driven by the release of endogenous opioids and that this endogenous opioid release is a common endpoint between different methods of neurostimulation. Finally, we introduce technological and clinical innovations that are being explored to optimize neurostimulation techniques for the treatment of pain, including multidisciplinary efforts between neuroscience research and clinical treatment that may refine the efficacy of neurostimulation based on its underlying mechanisms.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Robert D. Graham
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Robert Schaefer
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
- *Correspondence: Matthew R. Banghart,
| | - Meaghan C. Creed
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, United States
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO, United States
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
- Meaghan C. Creed,
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Vuka I, Marciuš T, Kovačić D, Šarolić A, Puljak L, Sapunar D. Implantable, Programmable, and Wireless Device for Electrical Stimulation of the Dorsal Root Ganglion in Freely-Moving Rats: A Proof of Concept Study. J Pain Res 2021; 14:3759-3772. [PMID: 34916842 PMCID: PMC8668248 DOI: 10.2147/jpr.s332438] [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: 08/03/2021] [Accepted: 11/23/2021] [Indexed: 11/23/2022] Open
Abstract
Objective This was a proof of concept study, based on systematic reviews of the efficacy and safety of the dorsal root ganglion (DRG) stimulation. The main objective was to develop an implantable, programmable, and wireless device for electrical stimulation of DRG and a methodology that can be used in translational research, especially to understand the mechanism of neuromodulation and to test new treatment modalities in animal models of pain. Methods We developed and tested a stimulator that uses a battery-powered microelectronic circuit, to generate constant current square biphasic or monophasic pulsed waveform of variable amplitudes and duration. It is controlled by software and an external controller that allows radio frequency communication with the stimulator. The stimulator was implanted in Sprague–Dawley (SD) rats. The lead was positioned at the L5 DRG level, while the stimulator was placed in the skin pocket at the ipsilateral side. Forty-five animals were used and divided into six groups: spinal nerve ligation (SNL), chronic compression injury of the DRG (CCD), SNL + active DRG stimulation, intact control group, group with the implanted sham stimulator, and sham lead. Behavioral testing was performed on the day preceding surgery and three times postoperatively (1st, 3rd, and 7th day). Results In animals with SNL, neurostimulation reduced pain-related behavior, tested with pinprick hyperalgesia, pinprick withdrawal test, and cold test, while the leads per se did not cause DRG compression. The rats well tolerated the stimulator. It did not hinder animal movement, and it enabled the animals to be housed under regular conditions. Conclusion A proof-of-concept experiment with our stimulator verified the usability of the device. The stimulator enables a wide range of research applications from adjusting stimulation parameters for different pain conditions, studying new stimulation methods with different frequencies and waveforms to obtain knowledge about analgesic mechanisms of DRG stimulation.
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Affiliation(s)
- Ivana Vuka
- Laboratory for Pain Research, University of Split School of Medicine, Split, Croatia
| | - Tihana Marciuš
- Laboratory for Pain Research, University of Split School of Medicine, Split, Croatia
| | - Damir Kovačić
- Laboratory for Biophysics and Medical Neuroelectronics, University of Split Faculty of Science, Split, Croatia
| | - Antonio Šarolić
- Laboratory for Applied Electromagnetics (EMLab), FESB, University of Split, Split, Croatia
| | - Livia Puljak
- Centre for Evidence-Based Medicine and Health Care, Catholic University of Croatia, Zagreb, Croatia
| | - Damir Sapunar
- Laboratory for Pain Research, University of Split School of Medicine, Split, Croatia
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Cho Y, Park S, Lee J, Yu KJ. Emerging Materials and Technologies with Applications in Flexible Neural Implants: A Comprehensive Review of Current Issues with Neural Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005786. [PMID: 34050691 DOI: 10.1002/adma.202005786] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/29/2020] [Indexed: 05/27/2023]
Abstract
Neuroscience is an essential field of investigation that reveals the identity of human beings, with a comprehensive understanding of advanced mental activities, through the study of neurobiological structures and functions. Fully understanding the neurotransmission system that allows for connectivity among neuronal circuits has paved the way for the development of treatments for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and depression. The field of flexible implants has attracted increasing interest mainly to overcome the mechanical mismatch between rigid electrode materials and soft neural tissues, enabling precise measurements of neural signals from conformal contact. Here, the current issues of flexible neural implants (chronic device failure, non-bioresorbable electronics, low-density electrode arrays, among others are summarized) by presenting material candidates and designs to address each challenge. Furthermore, the latest investigations associated with the aforementioned issues are also introduced, including suggestions for ideal neural implants. In terms of the future direction of these advances, designing flexible devices would provide new opportunities for the study of brain-machine interfaces or brain-computer interfaces as part of locomotion through brain signals, and for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Younguk Cho
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Sanghoon Park
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Juyoung Lee
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Ki Jun Yu
- School of Electrical Engineering, YU-KIST Institute, Yonsei University, Seoul, 03722, Korea
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9
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Jankowska E, Hammar I. The plasticity of nerve fibers: the prolonged effects of polarization of afferent fibers. J Neurophysiol 2021; 126:1568-1591. [PMID: 34525323 DOI: 10.1152/jn.00718.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The review surveys various aspects of the plasticity of nerve fibers, in particular the prolonged increase in their excitability evoked by polarization, focusing on a long-lasting increase in the excitability of myelinated afferent fibers traversing the dorsal columns of the spinal cord. We review the evidence that increased axonal excitability 1) follows epidurally applied direct current (DC) as well as relatively short (5 or 10 ms) current pulses and synaptically evoked intrinsic field potentials; 2) critically depends on the polarization of branching regions of afferent fibers at the sites where they bifurcate and give off axon collaterals entering the spinal gray matter in conjunction with actions of extrasynaptic GABAA membrane receptors; and 3) shares the feature of being activity-independent with the short-lasting effects of polarization of peripheral nerve fibers. A comparison between the polarization evoked sustained increase in the excitability of dorsal column fibers and spinal motoneurons (plateau potentials) indicates the possibility that they are mediated by partly similar membrane channels (including noninactivating type L Cav++ 1.3 but not Na+ channels) and partly different mechanisms. We finally consider under which conditions transspinally applied DC (tsDCS) might reproduce the effects of epidural polarization on dorsal column fibers and the possible advantages of increased excitability of afferent fibers for the rehabilitation of motor and sensory functions after spinal cord injuries.NEW & NOTEWORTHY This review supplements previous reviews of properties of nerve fibers by surveying recent experimental evidence for their long-term plasticity. It also extends recent descriptions of spinal effects of DC by reviewing effects of polarization of afferent nerve fibers within the dorsal columns, the mechanisms most likely underlying the long-lasting increase in their excitability and possible clinical implications.
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Affiliation(s)
- Elzbieta Jankowska
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ingela Hammar
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Badi M, Wurth S, Scarpato I, Roussinova E, Losanno E, Bogaard A, Delacombaz M, Borgognon S, C Vanc Ara P, Fallegger F, Su DK, Schmidlin E, Courtine G, Bloch J, Lacour SP, Stieglitz T, Rouiller EM, Capogrosso M, Micera S. Intrafascicular peripheral nerve stimulation produces fine functional hand movements in primates. Sci Transl Med 2021; 13:eabg6463. [PMID: 34705521 DOI: 10.1126/scitranslmed.abg6463] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Marion Badi
- Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics, and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Sophie Wurth
- Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics, and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Ilaria Scarpato
- Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics, and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Evgenia Roussinova
- Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics, and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Elena Losanno
- Biorobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, 56025 Pisa, Italy
| | - Andrew Bogaard
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Maude Delacombaz
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Simon Borgognon
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland.,Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, EPFL, 1015 Lausanne, Switzerland
| | - Paul C Vanc Ara
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, Bernstein Center Freiburg, and BrainLinks-BrainTools Center, University of Freiburg, 79110 Freiburg, Germany
| | - Florian Fallegger
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, 1202 Geneva, Switzerland
| | - David K Su
- Neurological Surgery, Harborview Medical Center, Seattle, WA 98104, USA
| | - Eric Schmidlin
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Grégoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, EPFL, 1015 Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL, University Hospital of Lausanne (CHUV), and University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Jocelyne Bloch
- Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL, University Hospital of Lausanne (CHUV), and University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, 1202 Geneva, Switzerland
| | - Thomas Stieglitz
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, Bernstein Center Freiburg, and BrainLinks-BrainTools Center, University of Freiburg, 79110 Freiburg, Germany
| | - Eric M Rouiller
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Marco Capogrosso
- Department of Neuroscience and Movement Sciences, Platform of Translational Neurosciences, Section of Medicine, Faculty of Sciences and Medicine, University of Fribourg, 1700 Fribourg, Switzerland.,Department of Neurological Surgery, Rehabilitation and Neural Engineering Laboratories, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Silvestro Micera
- Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics, and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.,Biorobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, 56025 Pisa, Italy
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11
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Tapias Pérez J. Spinal cord stimulation: beyond pain management. NEUROLOGÍA (ENGLISH EDITION) 2021; 37:586-595. [DOI: 10.1016/j.nrleng.2019.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/20/2019] [Indexed: 12/23/2022] Open
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Carnicer-Lombarte A, Chen ST, Malliaras GG, Barone DG. Foreign Body Reaction to Implanted Biomaterials and Its Impact in Nerve Neuroprosthetics. Front Bioeng Biotechnol 2021; 9:622524. [PMID: 33937212 PMCID: PMC8081831 DOI: 10.3389/fbioe.2021.622524] [Citation(s) in RCA: 149] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/19/2021] [Indexed: 12/04/2022] Open
Abstract
The implantation of any foreign material into the body leads to the development of an inflammatory and fibrotic process-the foreign body reaction (FBR). Upon implantation into a tissue, cells of the immune system become attracted to the foreign material and attempt to degrade it. If this degradation fails, fibroblasts envelop the material and form a physical barrier to isolate it from the rest of the body. Long-term implantation of medical devices faces a great challenge presented by FBR, as the cellular response disrupts the interface between implant and its target tissue. This is particularly true for nerve neuroprosthetic implants-devices implanted into nerves to address conditions such as sensory loss, muscle paralysis, chronic pain, and epilepsy. Nerve neuroprosthetics rely on tight interfacing between nerve tissue and electrodes to detect the tiny electrical signals carried by axons, and/or electrically stimulate small subsets of axons within a nerve. Moreover, as advances in microfabrication drive the field to increasingly miniaturized nerve implants, the need for a stable, intimate implant-tissue interface is likely to quickly become a limiting factor for the development of new neuroprosthetic implant technologies. Here, we provide an overview of the material-cell interactions leading to the development of FBR. We review current nerve neuroprosthetic technologies (cuff, penetrating, and regenerative interfaces) and how long-term function of these is limited by FBR. Finally, we discuss how material properties (such as stiffness and size), pharmacological therapies, or use of biodegradable materials may be exploited to minimize FBR to nerve neuroprosthetic implants and improve their long-term stability.
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Affiliation(s)
- Alejandro Carnicer-Lombarte
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Shao-Tuan Chen
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - George G. Malliaras
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Damiano G. Barone
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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13
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Greiner N, Barra B, Schiavone G, Lorach H, James N, Conti S, Kaeser M, Fallegger F, Borgognon S, Lacour S, Bloch J, Courtine G, Capogrosso M. Recruitment of upper-limb motoneurons with epidural electrical stimulation of the cervical spinal cord. Nat Commun 2021; 12:435. [PMID: 33469022 PMCID: PMC7815834 DOI: 10.1038/s41467-020-20703-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 12/16/2020] [Indexed: 12/21/2022] Open
Abstract
Epidural electrical stimulation (EES) of lumbosacral sensorimotor circuits improves leg motor control in animals and humans with spinal cord injury (SCI). Upper-limb motor control involves similar circuits, located in the cervical spinal cord, suggesting that EES could also improve arm and hand movements after quadriplegia. However, the ability of cervical EES to selectively modulate specific upper-limb motor nuclei remains unclear. Here, we combined a computational model of the cervical spinal cord with experiments in macaque monkeys to explore the mechanisms of upper-limb motoneuron recruitment with EES and characterize the selectivity of cervical interfaces. We show that lateral electrodes produce a segmental recruitment of arm motoneurons mediated by the direct activation of sensory afferents, and that muscle responses to EES are modulated during movement. Intraoperative recordings suggested similar properties in humans at rest. These modelling and experimental results can be applied for the development of neurotechnologies designed for the improvement of arm and hand control in humans with quadriplegia. The efficacy of epidural electrical stimulation (EES) to engage arm muscles and improve movement after spinal cord injury is still unclear. Here, the authors investigated how EES can recruit upper-limb motor neurons by combining computational modelling with experiments in non-human primates.
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Affiliation(s)
- Nathan Greiner
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland. .,Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Beatrice Barra
- Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Giuseppe Schiavone
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Henri Lorach
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), Lausanne, Switzerland
| | - Nicholas James
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Sara Conti
- Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Melanie Kaeser
- Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Florian Fallegger
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Simon Borgognon
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland.,Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Stéphanie Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Jocelyne Bloch
- Defitech Center for Interventional Neurotherapies (NeuroRestore), Lausanne, Switzerland.,Department of Neurosurgery, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Grégoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), Lausanne, Switzerland.,Department of Neurosurgery, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Marco Capogrosso
- Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland. .,Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA. .,Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA.
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14
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Xu X, Zhang H, Yan Y, Wang J, Guo L. Effects of electrical stimulation on skin surface. ACTA MECHANICA SINICA = LI XUE XUE BAO 2021; 37:1843-1871. [PMID: 33584001 PMCID: PMC7866966 DOI: 10.1007/s10409-020-01026-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/16/2020] [Accepted: 10/02/2020] [Indexed: 05/10/2023]
Abstract
ABSTRACT Skin is the largest organ in the body, and directly contact with the external environment. Articles on the role of micro-current and skin have emerged in recent years. The function of micro-current is various, including introducing various drugs into the skin locally or throughout the body, stimulating skin wounds healing through various currents, suppressing pain caused by various diseases, and promoting blood circulation for postoperative muscle rehabilitation, etc. This article reviews these efforts. Compared with various physical and chemical medical therapies, micro-current stimulation provides a relatively safe, non-invasive therapy with few side effects, giving modern medicine a more suitable treatment option. At the same time, the cost of the electrical stimulation generating device is relatively low, which makes it have wider space to and more clinical application value. The current micro-current stimulation technology has become more and more mature, but there are still many problems in its research. The design of the experiment and the selection of the current parameters not standardized and rigorous. Now, clear regulations are needed to regulate this field. Micro-current skin therapy has become a robust, reliable, and well-structured system.
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Affiliation(s)
- Xinkai Xu
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190 China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Han Zhang
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, 100049 China
- Key Laboratory of Noise and Vibration, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190 China
- State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190 China
| | - Yan Yan
- Cosmetic Technology Center, Chinese Academy of Inspection and Quarantine, Beijing, 100176 China
| | - Jianru Wang
- Xi’an Aerospace Propulsion Institute, Xi’an, 710100 China
| | - Liang Guo
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190 China
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15
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Yao Q, Guan J, Ma L, Cheng L, Duan F, Xu F, Zhao W, Duan W, Wu H, Chen Z, Jian F. Wireless Epidural Electrical Stimulation in Combination With Serotonin Agonists Improves Intraspinal Metabolism in Spinal Cord Injury Rats. Neuromodulation 2020; 24:416-426. [PMID: 33377590 DOI: 10.1111/ner.13344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/14/2020] [Accepted: 11/30/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The combination of epidural electrical stimulation (EES) and serotonin agonists (5-HTA) effectively restores rhythmic lower-limb movements and improves intraspinal hemodynamics after spinal cord injury (SCI). Nonetheless, whether EES + 5-HTA improves intraspinal metabolism remains unclear. The present study aimed to evaluate the effects of EES + 5-HTA on intraspinal metabolism in SCI rats. MATERIALS AND METHODS Wireless EES (WEES) implantation with complete T8 transection was performed in SCI rats. Electrodes were placed at the T12 and L2 vertebral levels. After rest for a week, the SCI rats received 11 weeks of WEES + 5-HTA treatment and treadmill training. WEES was switched off after each daily training. Locomotor function was evaluated by motion capture at week 12. Positron emission tomography-computed tomography was conducted to evaluate basal metabolism when WEES was switched off and assess task metabolism when WEES was switched on. RESULTS With locomotor recovery after training for 11 weeks, WEES + 5-HTA conjointly improved basal metabolism (vs. each intervention alone; p < 0.05) and linearly modulated task metabolism in a frequency-dependent manner (R2 = 0.8901). Furthermore, 60 Hz of WEES was identified as the threshold for the extensive activation of the spinal cord's task metabolism below the transection plane (p < 0.05). CONCLUSIONS WEES + 5-HTA could conjointly restore basal metabolism to a healthy level and modulate task metabolism by adjusting the stimulation frequency.
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Affiliation(s)
- Qingyu Yao
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jian Guan
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Longbing Ma
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Lei Cheng
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Feng Duan
- College of Artificial Intelligence, Nankai University, Tianjin, China
| | - Fu Xu
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Wang Zhao
- Department of Management Science, University of Strathclyde, Glasgow, UK
| | - Wanru Duan
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hao Wu
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zan Chen
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Fengzeng Jian
- Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.,Research Center of Spine and Spinal Cord, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
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16
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Pikov V, McCreery DB, Han M. Intraspinal stimulation with a silicon-based 3D chronic microelectrode array for bladder voiding in cats. J Neural Eng 2020; 17. [PMID: 33181490 PMCID: PMC8113353 DOI: 10.1088/1741-2552/abca13] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 11/12/2020] [Indexed: 12/31/2022]
Abstract
Objective. Bladder dysfunction is a significant and largely unaddressed problem for people living with spinal cord injury (SCI). Intermittent catheterization does not provide volitional control of micturition and has numerous side effects. Targeted electrical microstimulation of the spinal cord has been previously explored for restoring such volitional control in the animal model of experimental SCI. Here, we continue the development of the intraspinal microstimulation array technology to evaluate its ability to provide more focused and reliable bladder control in the feline animal model. Approach. For the first time, a mechanically robust intraspinal multisite silicon array was built using novel microfabrication processes to provide custom-designed tip geometry and 3D electrode distribution. Long-term implantation was performed in eight spinally intact animals for a period up to 6 months, targeting the dorsal gray commissure area in the S2 sacral cord that is known to be involved in the coordination between the bladder detrusor and the external urethral sphincter. Main results. About one third of the electrode sites in the that area produced micturition-related responses. The effectiveness of stimulation was further evaluated in one of eight animals after spinal cord transection (SCT). We observed increased bladder responsiveness to stimulation starting at 1 month post-transection, possibly due to supraspinal disinhibition of the spinal circuitry and/or hypertrophy and hyperexcitability of the spinal bladder afferents. Significance. 3D intraspinal microstimulation arrays can be chronically implanted and provide a beneficial effect on the bladder voiding in the intact spinal cord and after SCT. However, further studies are required to assess longer-term reliability and safety of the developed intraspinal microstimulation array prior to eventual human translation.
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Affiliation(s)
- Victor Pikov
- Medipace Inc, Pasadena, California, UNITED STATES
| | - Douglas B McCreery
- Neural Engineeiring Laboratory, Huntington Medical Research Institute, 734 Fairmount Avenue, Pasadena CA 91105, USA, Pasadena, California, 91105, UNITED STATES
| | - Martin Han
- Biomedical Engineering, University of Connecticut at Storrs , 260 Glenbrook Rd., Unit 3247, Storrs, Connecticut, 06269-3247, UNITED STATES
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17
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Agadagba SK, Li X, Chan LLH. Excitation of the Pre-frontal and Primary Visual Cortex in Response to Transcorneal Electrical Stimulation in Retinal Degeneration Mice. Front Neurosci 2020; 14:572299. [PMID: 33162879 PMCID: PMC7584448 DOI: 10.3389/fnins.2020.572299] [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] [Received: 06/13/2020] [Accepted: 09/08/2020] [Indexed: 11/13/2022] Open
Abstract
Retinal degeneration (rd) is one of the leading causes of blindness in the modern world today. Various strategies including electrical stimulation are being researched for the restoration of partial or complete vision. Previous studies have demonstrated that the effectiveness of electrical stimulation in somatosensory, frontal and visual cortices is dependent on stimulation parameters including stimulation frequency and brain states. The aim of the study is to investigate the effect of applying a prolonged electrical stimulation on the eye of rd mice with various stimulation frequencies, in awake and anesthetized brain states. We recorded spontaneous electrocorticogram (ECoG) neural activity in prefrontal cortex and primary visual cortex in a mouse model of retinitis pigmentosa (RP) after prolonged (5-day) transcorneal electrical stimulation (pTES) at various frequencies (2, 10, and 20 Hz). We evaluated the absolute power and coherence of spontaneous ECoG neural activities in contralateral primary visual cortex (contra Vcx) and contralateral pre-frontal cortex (contra PFx). Under the awake state, the absolute power of theta, alpha and beta oscillations in contra Vcx, at 10 Hz stimulation, was higher than in the sham group. Under the anesthetized state, the absolute power of medium-, high-, and ultra-high gamma oscillations in the contra PFx, at 2 Hz stimulation, was higher than in the sham group. We also observed that the ultra-high gamma band coherence in contra Vcx-contra PFx was higher than in the sham group, with both 10 and 20 Hz stimulation frequencies. Our results showed that pTES modulates rd brain oscillations in a frequency and brain state-dependent manner. These findings suggest that non-invasive electrical stimulation of retina changes patterns of neural oscillations in the brain circuitry. This also provides a starting point for investigating the sustained effect of electrical stimulation of the retina to brain activities.
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Affiliation(s)
- Stephen K Agadagba
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong
| | - Xin Li
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong
| | - Leanne Lai Hang Chan
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong
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18
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Shkorbatova P, Lyakhovetskii V, Pavlova N, Popov A, Bazhenova E, Kalinina D, Gorskii O, Musienko P. Mapping of the Spinal Sensorimotor Network by Transvertebral and Transcutaneous Spinal Cord Stimulation. Front Syst Neurosci 2020; 14:555593. [PMID: 33162882 PMCID: PMC7581734 DOI: 10.3389/fnsys.2020.555593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 09/15/2020] [Indexed: 11/13/2022] Open
Abstract
Transcutaneous stimulation is a neuromodulation method that is efficiently used for recovery after spinal cord injury and other disorders that are accompanied by motor and sensory deficits. Multiple aspects of transcutaneous stimulation optimization still require testing in animal experiments including the use of pharmacological agents, spinal lesions, cell recording, etc. This need initially motivated us to develop a new approach of transvertebral spinal cord stimulation (SCS) and to test its feasibility in acute and chronic experiments on rats. The aims of the current work were to study the selectivity of muscle activation over the lower thoracic and lumbosacral spinal cord when the stimulating electrode was located intravertebrally and to compare its effectiveness to that of the clinically used transcutaneous stimulation. In decerebrated rats, electromyographic activity was recorded in the muscles of the back (m. longissimus dorsi), tail (m. abductor caudae dorsalis), and hindlimb (mm. iliacus, adductor magnus, vastus lateralis, semitendinosus, tibialis anterior, gastrocnemius medialis, soleus, and flexor hallucis longus) during SCS with an electrode placed alternately in one of the spinous processes of the VT12-VS1 vertebrae. The recruitment curves for motor and sensory components of the evoked potentials (separated from each other by means of double-pulse stimulation) were plotted for each muscle; their slopes characterized the effectiveness of the muscle activation. The electrophysiological mapping demonstrated that transvertebral SCS has specific effects to the rostrocaudally distributed sensorimotor network of the lower thoracic and lumbosacral cord, mainly by stimulation of the roots that carry the sensory and motor spinal pathways. These effects were compared in the same animals when mapping was performed by transcutaneous stimulation, and similar distribution of muscle activity and underlying neuroanatomical mechanisms were found. The experiments on chronic rats validated the feasibility of the proposed stimulation approach of transvertebral SCS for further studies.
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Affiliation(s)
- Polina Shkorbatova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vsevolod Lyakhovetskii
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
- Russian Research Center of Radiology and Surgical Technologies, Ministry of Health of the Russian Federation, Saint Petersburg, Russia
| | - Natalia Pavlova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Alexander Popov
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Elena Bazhenova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Daria Kalinina
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Oleg Gorskii
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
- Russian Research Center of Radiology and Surgical Technologies, Ministry of Health of the Russian Federation, Saint Petersburg, Russia
| | - Pavel Musienko
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
- Russian Research Center of Radiology and Surgical Technologies, Ministry of Health of the Russian Federation, Saint Petersburg, Russia
- Children’s Surgery and Orthopedic Clinic, Department of Non-pulmonary Tuberculosis, Institute of Phthysiopulmonology, Saint Petersburg, Russia
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19
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Woodroffe RW, Pearson AC, Pearlman AM, Howard MA, Nauta HJW, Nagel SJ, Hori YS, Machado AG, Almeida Frizon L, Helland L, Holland MT, Gillies GT, Wilson S. Spinal Cord Stimulation for Visceral Pain: Present Approaches and Future Strategies. PAIN MEDICINE 2020; 21:2298-2309. [PMID: 32719876 DOI: 10.1093/pm/pnaa108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The introduction of successful neuromodulation strategies for managing chronic visceral pain lag behind what is now treatment of choice in refractory chronic back and extremity pain for many providers in the United States and Europe. Changes in public policy and monetary support to identify nonopioid treatments for chronic pain have sparked interest in alternative options. In this review, we discuss the scope of spinal cord stimulation (SCS) for visceral pain, its limitations, and the potential role for new intradural devices of the type that we are developing in our laboratories, which may be able to overcome existing challenges. METHODS A review of the available literature relevant to this topic was performed, with particular focus on the pertinent neuroanatomy and uses of spinal cord stimulation systems in the treatment of malignant and nonmalignant gastrointestinal, genitourinary, and chronic pelvic pain. RESULTS To date, there have been multiple off-label reports testing SCS for refractory gastrointestinal and genitourinary conditions. Though some findings have been favorable for these organs and systems, there is insufficient evidence to make this practice routine. The unique configuration and layout of the pelvic pain pathways may not be ideally treated using traditional SCS implantation techniques, and intradural stimulation may be a viable alternative. CONCLUSIONS Despite the prevalence of visceral pain, the application of neuromodulation therapies, a standard approach for other painful conditions, has received far too little attention, despite promising outcomes from uncontrolled trials. Detailed descriptions of visceral pain pathways may offer several clues that could be used to implement devices tailored to this unique anatomy.
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Affiliation(s)
- Royce W Woodroffe
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Amy C Pearson
- Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Amy M Pearlman
- Department of Urology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Matthew A Howard
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Haring J W Nauta
- Department of Neurosurgery, University of Louisville, Louisville, Kentucky
| | - S J Nagel
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, Ohio, USA
| | - Y S Hori
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, Ohio, USA
| | - Andre G Machado
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Logan Helland
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Marshall T Holland
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - George T Gillies
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Saul Wilson
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
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20
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Keogh C. Optimizing the neuron-electrode interface for chronic bioelectronic interfacing. Neurosurg Focus 2020; 49:E7. [PMID: 32610294 DOI: 10.3171/2020.4.focus20178] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 04/08/2020] [Indexed: 11/06/2022]
Abstract
Engineering approaches have vast potential to improve the treatment of disease. Brain-machine interfaces have become a well-established means of treating some otherwise medically refractory neurological diseases, and they have shown promise in many more areas. More widespread use of implanted stimulating and recording electrodes for long-term intervention is, however, limited by the difficulty in maintaining a stable interface between implanted electrodes and the local tissue for reliable recording and stimulation.This loss of performance at the neuron-electrode interface is due to a combination of inflammation and glial scar formation in response to the implanted material, as well as electrical factors contributing to a reduction in function over time. An increasing understanding of the factors at play at the neural interface has led to greater focus on the optimization of this neuron-electrode interface in order to maintain long-term implant viability.A wide variety of approaches to improving device interfacing have emerged, targeting the mechanical, electrical, and biological interactions between implanted electrodes and the neural tissue. These approaches are aimed at reducing the initial trauma and long-term tissue reaction through device coatings, optimization of mechanical characteristics for maximal biocompatibility, and implantation techniques. Improved electrode features, optimized stimulation parameters, and novel electrode materials further aim to stabilize the electrical interface, while the integration of biological interventions to reduce inflammation and improve tissue integration has also shown promise.Optimization of the neuron-electrode interface allows the use of long-term, high-resolution stimulation and recording, opening the door to responsive closed-loop systems with highly selective modulation. These new approaches and technologies offer a broad range of options for neural interfacing, representing the possibility of developing specific implant technologies tailor-made to a given task, allowing truly personalized, optimized implant technology for chronic neural interfacing.
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21
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Li Y, Hari K, Lucas-Osma AM, Fenrich KK, Bennett DJ, Hammar I, Jankowska E. Branching points of primary afferent fibers are vital for the modulation of fiber excitability by epidural DC polarization and by GABA in the rat spinal cord. J Neurophysiol 2020; 124:49-62. [PMID: 32459560 DOI: 10.1152/jn.00161.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The aim of the study was to examine whether the sustained increases in the excitability of afferent fibers traversing the dorsal columns evoked by their polarization depend on the branching points of these fibers. To this end, the effects of epidural polarization were compared in four spinal regions in deeply anesthetized rats; two with the densest collateralization of muscle afferent fibers (above motor nuclei and Clarke's column) and two where the collateralization is more sparse (rostral and caudal to motor nuclei, respectively. The degree of collateralization in different segments was reconstructed in retrogradely labeled afferent fibers in the rat. Nerve volleys evoked in peripheral nerves by electrical stimulation of the dorsal columns within these regions were used as a measure of the excitability of the stimulated fibers. Potent increases in the excitability were evoked by polarization above motor nuclei and Clarke's column, both during constant direct current (DC) polarization (1 µA for 1 min) and for at least 30 min following DC polarization. Smaller excitability increases occurred during the polarization within other regions and were thereafter either absent or rapidly declined after its termination. The postpolarization increases in excitability were counteracted by the GABAA receptor antagonist bicuculline and the α5GABAA extrasynaptic receptor antagonist L655708 and enhanced by the GABAA receptor agonist muscimol and by ionophoretically applied GABA. As extrasynaptic α5GABAA receptors have been found close to Na channels within branching points, these results are consistent with the involvement of branching points in the induction of the sustained postpolarization increases in fiber excitability.NEW & NOTEWORTHY Polarization of sensory fibers traversing dorsal columns of the spinal cord may considerably increase the excitability of these fibers. We show that this involves the effects of current at branching points of afferent fibers and depends on extrasynaptic effects of GABA. These results contribute to our understanding of the mechanism underlying plasticity of activation of nerve fibers and may be used to increase the effectiveness of epidural stimulation in humans and recovery of spinal functions.
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Affiliation(s)
- Yaqing Li
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Krishnapriya Hari
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Neuroscience and Mental Health Institute and Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Ana M Lucas-Osma
- Neuroscience and Mental Health Institute and Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Keith K Fenrich
- Neuroscience and Mental Health Institute and Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - David J Bennett
- Neuroscience and Mental Health Institute and Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Ingela Hammar
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Elzbieta Jankowska
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
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22
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Capogrosso M, Lempka SF. A computational outlook on neurostimulation. Bioelectron Med 2020; 6:10. [PMID: 32490037 PMCID: PMC7247210 DOI: 10.1186/s42234-020-00047-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/08/2020] [Indexed: 12/16/2022] Open
Abstract
Efficient identification of effective neurostimulation strategies is critical due to the growing number of clinical applications and the increasing complexity of the corresponding technology. In consequence, investigators are encouraged to accelerate translational research of neurostimulation technologies and move quickly to clinical applications. However, this process is hampered by rigorous, but necessary, regulations and lack of a mechanistic understanding of the interactions between electric fields and neural circuits. Here we discuss how computational models have influenced the field of neurostimulation for pain and movement recovery, deep brain stimulation, and even device regulations. Finally, we propose our vision on how computational models will be key to accelerate clinical developments through mechanistic understanding.
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Affiliation(s)
- Marco Capogrosso
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA USA.,Rehabilitation Neural Engineering Laboratories, University of Pittsburgh, Pittsburgh, PA USA
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI USA.,Department of Anesthesiology, University of Michigan, Ann Arbor, MI USA
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23
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Schiavone G, Fallegger F, Kang X, Barra B, Vachicouras N, Roussinova E, Furfaro I, Jiguet S, Seáñez I, Borgognon S, Rowald A, Li Q, Qin C, Bézard E, Bloch J, Courtine G, Capogrosso M, Lacour SP. Soft, Implantable Bioelectronic Interfaces for Translational Research. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1906512. [PMID: 32173913 DOI: 10.1002/adma.201906512] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/19/2019] [Indexed: 06/10/2023]
Abstract
The convergence of materials science, electronics, and biology, namely bioelectronic interfaces, leads novel and precise communication with biological tissue, particularly with the nervous system. However, the translation of lab-based innovation toward clinical use calls for further advances in materials, manufacturing and characterization paradigms, and design rules. Herein, a translational framework engineered to accelerate the deployment of microfabricated interfaces for translational research is proposed and applied to the soft neurotechnology called electronic dura mater, e-dura. Anatomy, implant function, and surgical procedure guide the system design. A high-yield, silicone-on-silicon wafer process is developed to ensure reproducible characteristics of the electrodes. A biomimetic multimodal platform that replicates surgical insertion in an anatomy-based model applies physiological movement, emulates therapeutic use of the electrodes, and enables advanced validation and rapid optimization in vitro of the implants. Functionality of scaled e-dura is confirmed in nonhuman primates, where epidural neuromodulation of the spinal cord activates selective groups of muscles in the upper limbs with unmet precision. Performance stability is controlled over 6 weeks in vivo. The synergistic steps of design, fabrication, and biomimetic in vitro validation and in vivo evaluation in translational animal models are of general applicability and answer needs in multiple bioelectronic designs and medical technologies.
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Affiliation(s)
- Giuseppe Schiavone
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Florian Fallegger
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Xiaoyang Kang
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Beatrice Barra
- Department of Neuroscience and Movement Science, University of Fribourg, Fribourg, 1700, Switzerland
| | - Nicolas Vachicouras
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Evgenia Roussinova
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Ivan Furfaro
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Sébastien Jiguet
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
| | - Ismael Seáñez
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Simon Borgognon
- Department of Neuroscience and Movement Science, University of Fribourg, Fribourg, 1700, Switzerland
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Andreas Rowald
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Qin Li
- Institute of Lab Animal Sciences, China Academy of Medical Sciences, Beijing, 100021, China
- Motac Neuroscience Ltd, Manchester, SK10 4TF, UK
| | - Chuan Qin
- Institute of Lab Animal Sciences, China Academy of Medical Sciences, Beijing, 100021, China
| | - Erwan Bézard
- Institute of Lab Animal Sciences, China Academy of Medical Sciences, Beijing, 100021, China
- Motac Neuroscience Ltd, Manchester, SK10 4TF, UK
- Institut des Maladies Neurodégénératives, University of Bordeaux, Bordeaux, UMR 5293, France
- CNRS, Institut des Maladies Neurodégénératives, Bordeaux, UMR 5293, France
| | - Jocelyne Bloch
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore), Department of Neurosurgery, University Hospital of Lausanne (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Grégoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore), Department of Neurosurgery, University Hospital of Lausanne (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Marco Capogrosso
- Department of Neuroscience and Movement Science, University of Fribourg, Fribourg, 1700, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland
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24
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Nagel SJ, Frizon L, Maiti T, Machado AG, Gillies GT, Helland L, Woodroffe RW, Howard MA, Wilson S. Contemporary Approaches to Preventing and Treating Infections of Novel Intrathecal Neurostimulation Devices. World Neurosurg 2019; 128:e397-e408. [DOI: 10.1016/j.wneu.2019.04.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/18/2019] [Accepted: 04/19/2019] [Indexed: 02/04/2023]
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25
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Configuration of electrical spinal cord stimulation through real-time processing of gait kinematics. Nat Protoc 2019; 13:2031-2061. [PMID: 30190556 DOI: 10.1038/s41596-018-0030-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Epidural electrical stimulation (EES) of the spinal cord and real-time processing of gait kinematics are powerful methods for the study of locomotion and the improvement of motor control after injury or in neurological disorders. Here, we describe equipment and surgical procedures that can be used to acquire chronic electromyographic (EMG) recordings from leg muscles and to implant targeted spinal cord stimulation systems that remain stable up to several months after implantation in rats and nonhuman primates. We also detail how to exploit these implants to configure electrical spinal cord stimulation policies that allow control over the degree of extension and flexion of each leg during locomotion. This protocol uses real-time processing of gait kinematics and locomotor performance, and can be configured within a few days. Once configured, stimulation bursts are delivered over specific spinal cord locations with precise timing that reproduces the natural spatiotemporal activation of motoneurons during locomotion. These protocols can also be easily adapted for the safe implantation of systems in the vicinity of the spinal cord and to conduct experiments involving real-time movement feedback and closed-loop controllers.
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26
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Calvert JS, Grahn PJ, Zhao KD, Lee KH. Emergence of Epidural Electrical Stimulation to Facilitate Sensorimotor Network Functionality After Spinal Cord Injury. Neuromodulation 2019; 22:244-252. [PMID: 30840354 DOI: 10.1111/ner.12938] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 01/15/2019] [Accepted: 01/19/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Traumatic spinal cord injury (SCI) disrupts signaling pathways between the brain and spinal networks below the level of injury. In cases of severe SCI, permanent loss of sensorimotor and autonomic function can occur. The standard of care for severe SCI uses compensation strategies to maximize independence during activities of daily living while living with chronic SCI-related dysfunctions. Over the past several years, the research field of spinal neuromodulation has generated promising results that hold potential to enable recovery of functions via epidural electrical stimulation (EES). METHODS This review provides a historical account of the translational research efforts that led to the emergence of EES of the spinal cord to enable intentional control of motor functions that were lost after SCI. We also highlight the major limitations associated with EES after SCI and propose future directions of spinal neuromodulation research. RESULTS Multiple, independent studies have demonstrated return of motor function via EES in individuals with chronic SCI. These enabled motor functions include intentional, controlled movement of previously paralyzed extremities, independent standing and stepping, and increased grip strength. In addition, improvements in cardiovascular health, respiratory function, body composition, and urologic function have been reported. CONCLUSIONS EES holds promise to enable functions thought to be permanently lost due to SCI. However, EES is currently restricted to scientific investigation in humans with SCI and requires further validation of factors such as safety and efficacy before clinical translation.
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Affiliation(s)
| | - Peter J Grahn
- Department of Neurologic Surgery, Rochester, MN, USA.,Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA
| | - Kristin D Zhao
- Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Kendall H Lee
- Department of Neurologic Surgery, Rochester, MN, USA.,Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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27
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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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28
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Taylor MJ, Fornusek C, Ruys AJ. The duty cycle in Functional Electrical Stimulation research. Part II: Duty cycle multiplicity and domain reporting. Eur J Transl Myol 2018; 28:7733. [PMID: 30662696 PMCID: PMC6317134 DOI: 10.4081/ejtm.2018.7733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/21/2018] [Indexed: 12/17/2022] Open
Abstract
In part I of this review, we introduced the duty cycle as a fundamental parameter in controlling the effect of electrical stimulation pulse trains on muscle structural and functional properties with special emphasis on fatigue. Following on from a survey of the literature, we discuss here the relative ability of intermittent and continuous stimulation to fatigue muscle. In addition, pertinent literature is explored on a more deeper level, highlighting contentions regarding the duty cycle across studies. In response to literature inconsistencies, we propose frameworks upon which the duty cycle parameter may be specified. We present the idea of domain reporting for the duty cycle, and illustrate with practical examples. In addition we dig further into the literature and present a set of notations that have been used by different researchers to report the duty cycle. We also propose the idea of the duty cycle multiple, which together with domain reporting, will help researchers understand more precisely duty cycles of electrical stimulation. As a case study, we also show how the duty cycle has been looked at by researchers in the context of pressure sore attenuation in patients. Together with part I, it is hoped that the frameworks suggested provide a complete picture of how duty cycle has been discussed across the literature, and gives researchers a more trans-theoretical basis upon which they may report the duty cycle in their studies. This may also lead to a more precise specification of electrical stimulation protocols used in patients.
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Affiliation(s)
- Matthew J. Taylor
- Faculty of Engineering and IT, University of Sydney, Camperdown, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, Australia
| | - Ché Fornusek
- Faculty of Medicine and Health, University of Sydney, Lidcombe, Australia
| | - Andrew J. Ruys
- Faculty of Engineering and IT, University of Sydney, Camperdown, Australia
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29
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Taylor MJ, Fornusek C, Ruys AJ. Reporting for Duty: The duty cycle in Functional Electrical Stimulation research. Part I: Critical commentaries of the literature. Eur J Transl Myol 2018; 28:7732. [PMID: 30662695 PMCID: PMC6317136 DOI: 10.4081/ejtm.2018.7732] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/21/2018] [Indexed: 02/07/2023] Open
Abstract
There are several parameters that can be modulated during electrical stimulation-induced muscle contraction to obtain external work, i.e., Functional Electrical Stimulation (FES). The literature has several reports of the relationships of parameters such as frequency, pulse width, amplitude and physiological or biomechanical outcomes (i.e., torque) when these parameters are changed. While these relationships are well-described, lesser known across the literature is how changing the duty cycle (time ON and time OFF) of stimulation affects the outcomes. This review provides an analysis of the literature pertaining to the duty cycle in electrical stimulation experiments. There are two distinct sections of this review - an introduction to the duty cycle and definitions from literature (part I); and contentions from the literature and proposed frameworks upon which duty cycle can be interpreted (part II). It is envisaged that the two reviews will highlight the importance of modulating the duty cycle in terms of muscle fatigue in mimicking physiological activities. The frameworks provided will ideally assist in unifying how researchers consider the duty cycle in electrical stimulation (ES) of muscles.
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Affiliation(s)
- Matthew J. Taylor
- Faculty of Engineering and IT, University of Sydney, Camperdown, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, Australia
| | - Ché Fornusek
- Faculty of Medicine and Health, University of Sydney, Lidcombe, Australia
| | - Andrew J. Ruys
- Faculty of Engineering and IT, University of Sydney, Camperdown, Australia
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