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Agyeman KA, Lee DJ, Russin J, Kreydin EI, Choi W, Abedi A, Lo YT, Cavaleri J, Wu K, Edgerton VR, Liu C, Christopoulos VN. Functional ultrasound imaging of the human spinal cord. Neuron 2024:S0896-6273(24)00122-3. [PMID: 38458198 DOI: 10.1016/j.neuron.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 11/03/2023] [Accepted: 02/15/2024] [Indexed: 03/10/2024]
Abstract
Utilizing the first in-human functional ultrasound imaging (fUSI) of the spinal cord, we demonstrate the integration of spinal functional responses to electrical stimulation. We record and characterize the hemodynamic responses of the spinal cord to a neuromodulatory intervention commonly used for treating pain and increasingly used for the restoration of sensorimotor and autonomic function. We found that the hemodynamic response to stimulation reflects a spatiotemporal modulation of the spinal cord circuitry not previously recognized. Our analytical capability offers a mechanism to assess blood flow changes with a new level of spatial and temporal precision in vivo and demonstrates that fUSI can decode the functional state of spinal networks in a single trial, which is of fundamental importance for developing real-time closed-loop neuromodulation systems. This work is a critical step toward developing a vital technique to study spinal cord function and effects of clinical neuromodulation.
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Affiliation(s)
- K A Agyeman
- Department of Bioengineering, University of California Riverside, Riverside, CA, USA
| | - D J Lee
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA; Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - J Russin
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA; Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - E I Kreydin
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA; Institute of Urology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - W Choi
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - A Abedi
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Y T Lo
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Department of Neurosurgery, National Neuroscience Institute, Singapore, Singapore
| | - J Cavaleri
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - K Wu
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - V R Edgerton
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA.
| | - C Liu
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA; Institute of Urology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA.
| | - V N Christopoulos
- Department of Bioengineering, University of California Riverside, Riverside, CA, USA; Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Neuroscience Graduate Program, University of California Riverside, Riverside, CA, USA.
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Chalif JI, Chavarro VS, Mensah E, Johnston B, Fields DP, Chalif EJ, Chiang M, Sutton O, Yong R, Trumbower R, Lu Y. Epidural Spinal Cord Stimulation for Spinal Cord Injury in Humans: A Systematic Review. J Clin Med 2024; 13:1090. [PMID: 38398403 PMCID: PMC10889415 DOI: 10.3390/jcm13041090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
(1) Background: Spinal cord injury (SCI) represents a major health challenge, often leading to significant and permanent sensorimotor and autonomic dysfunctions. This study reviews the evolving role of epidural spinal cord stimulation (eSCS) in treating chronic SCI, focusing on its efficacy and safety. The objective was to analyze how eSCS contributes to the recovery of neurological functions in SCI patients. (2) Methods: We utilized the PRISMA guidelines and performed a comprehensive search across MEDLINE/PubMed, Embase, Web of Science, and IEEE Xplore databases up until September 2023. We identified studies relevant to eSCS in SCI and extracted assessments of locomotor, cardiovascular, pulmonary, and genitourinary functions. (3) Results: A total of 64 studies encompassing 306 patients were identified. Studies investigated various stimulation devices, parameters, and rehabilitation methods. Results indicated significant improvements in motor function: 44% of patients achieved assisted or independent stepping or standing; 87% showed enhanced muscle activity; 65% experienced faster walking speeds; and 80% improved in overground walking. Additionally, eSCS led to better autonomic function, evidenced by improvements in bladder and sexual functions, airway pressures, and bowel movements. Notable adverse effects included device migration, infections, and post-implant autonomic dysreflexia, although these were infrequent. (4) Conclusion: Epidural spinal cord stimulation is emerging as an effective and generally safe treatment for chronic SCI, particularly when combined with intensive physical rehabilitation. Future research on standardized stimulation parameters and well-defined therapy regimens will optimize benefits for specific patient populations.
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Affiliation(s)
- J. I. Chalif
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA; (J.I.C.); (V.S.C.); (B.J.)
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
| | - V. S. Chavarro
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA; (J.I.C.); (V.S.C.); (B.J.)
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
- Department of Physical Medicine and Rehabilitation, Spaulding Hospital Cambridge, Cambridge, MA 02115, USA
| | - E. Mensah
- Chan School of Public Health, Harvard University, Boston, MA 02115, USA;
| | - B. Johnston
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA; (J.I.C.); (V.S.C.); (B.J.)
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
| | - D. P. Fields
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15261, USA;
| | - E. J. Chalif
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA; (J.I.C.); (V.S.C.); (B.J.)
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
| | - M. Chiang
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
- Department of Physical Medicine and Rehabilitation, Spaulding Hospital Cambridge, Cambridge, MA 02115, USA
- Department of Anesthesiology Perioperative and Pain Management, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - O. Sutton
- Department of Anesthesiology Perioperative and Pain Management, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - R. Yong
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
- Department of Anesthesiology Perioperative and Pain Management, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - R. Trumbower
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
- Department of Physical Medicine and Rehabilitation, Spaulding Hospital Cambridge, Cambridge, MA 02115, USA
| | - Y. Lu
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA; (J.I.C.); (V.S.C.); (B.J.)
- Harvard Medical School, Boston, MA 02115, USA; (M.C.); (R.Y.); (R.T.)
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3
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Hackethal S, Maino P, Koetsier E, Manconi M. Spinal cord stimulation in severe pharmacoresistant restless legs syndrome-two case reports. Front Neurol 2023; 14:1219881. [PMID: 38099065 PMCID: PMC10720037 DOI: 10.3389/fneur.2023.1219881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/18/2023] [Indexed: 12/17/2023] Open
Abstract
Restless legs syndrome is a prevalent, sleep-related sensorimotor disorder with relevant impact on the patients' quality of life. For patients suffering from severe, pharmacoresistant restless legs syndrome, few therapeutic options remain to alleviate symptoms. In this case series, two patients with severe, pharmacoresistant restless legs syndrome were treated with epidural spinal cord stimulation and repeatedly assessed with polysomnography, including sleep structure and periodic limb movements as objective biomarkers not subject to placebo effects, during a 6-month follow-up period. One of the patients experienced excellent short- and long-term efficacy on subjective symptom severity (International RLS Study group rating scale 1 vs. 34 points at 3 months) and objective sleep parameters such as sleep architecture and periodic limb movements during sleep, while the second patient only reported short-term benefits from spinal cord stimulation. Ultimately, both patients opted for removal of the device for inefficacy. Based on the complex pathophysiology of restless legs syndrome and presumed mechanism of action of spinal cord stimulation in chronic pain disorders, we provide a detailed hypothesis on the possible modulating effect of spinal cord stimulation on the key symptoms of restless legs syndrome. Apart from describing a new therapeutic option for pharmacoresistant restless legs syndrome, our findings might also provide further insights into the pathophysiology of the syndrome.
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Affiliation(s)
- Sandra Hackethal
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Paolo Maino
- Pain Management Center, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
| | - Eva Koetsier
- Pain Management Center, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
| | - Mauro Manconi
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
- Department of Neurology, University Hospital, Inselspital, Bern, Switzerland
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Hoglund BK, Zurn CA, Madden LR, Hoover C, Slopsema JP, Balser D, Parr A, Samadani U, Johnson MD, Netoff TI, Darrow DP. Mapping Spinal Cord Stimulation-Evoked Muscle Responses in Patients With Chronic Spinal Cord Injury. Neuromodulation 2023; 26:1371-1380. [PMID: 36517395 DOI: 10.1016/j.neurom.2022.10.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/23/2022] [Accepted: 10/31/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVES Epidural spinal cord stimulation (eSCS) has shown promise for restoring some volitional motor control after spinal cord injury (SCI). Maximizing therapeutic response requires effective spatial stimulation generated through careful configuration of anodes and cathodes on the eSCS lead. By exploring the way the spatial distribution of low frequency stimulation affects muscle activation patterns, we investigated the spatial specificity of stimulation-evoked responses for targeted muscle groups for restoration after chronic SCI (cSCI) in participants in the Epidural Stimulation After Neurologic Damage (E-STAND) trial. MATERIALS AND METHODS Fifteen participants with Abbreviated Injury Scale A cSCI from the E-STAND study were evaluated with a wide range of bipolar spatial patterns. Surface electromyography captured stimulation-evoked responses from the rectus abdominis (RA), intercostal, paraspinal, iliopsoas, rectus femoris (RF), tibialis anterior (TA), extensor hallucis longus (EHL), and gastrocnemius muscle groups bilaterally. Peak-to-peak amplitudes were analyzed for each pulse across muscles. Stimulation patterns with dipoles parallel (vertical configurations), perpendicular (horizontal configurations), and oblique (diagonal configurations) relative to the rostral-caudal axis were evaluated. RESULTS Cathodic stimulation in the transverse plane indicated ipsilaterally biased activation in RA, intercostal, paraspinal, iliopsoas, RF, TA, EHL, and gastrocnemius muscles (p < 0.05). We found that caudal cathodic stimulation was significantly more activating only in the RF and EHL muscle groups than in the rostral (p < 0.037 and p < 0.006, respectively). Oblique stimulation was found to be more activating in the RA, intercostal, paraspinal, iliopsoas, and TA muscle groups than in the transverse (p < 0.05). CONCLUSIONS Cathodic stimulation provides uniform specificity for targeting laterality. Few muscle groups responded specifically to variation in rostral/caudal stimulation, and oblique stimulation improved stimulation responses when compared with horizontal configurations. These relations may enable tailored targeting of muscle groups, but the surprising amount of variation observed suggests that monitoring these evoked muscle responses will play a key role in this tailoring process. CLINICAL TRIAL REGISTRATION The Clinicaltrials.gov registration number for the study is NCT03026816.
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Affiliation(s)
| | - Claire A Zurn
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Lauren R Madden
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Caleb Hoover
- Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Julia P Slopsema
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - David Balser
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Ann Parr
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, USA
| | - Uzma Samadani
- Department of Surgery, Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, USA
| | - Matthew D Johnson
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Theoden I Netoff
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - David P Darrow
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, USA; Division of Neurosurgery, Department of Surgery, Hennepin County Medical Center, Minneapolis, MN, USA.
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Ramadan A, König SD, Zhang M, Ross EK, Herman A, Netoff TI, Darrow DP. Methods and system for recording human physiological signals from implantable leads during spinal cord stimulation. Front Pain Res (Lausanne) 2023; 4:1072786. [PMID: 36937564 PMCID: PMC10020336 DOI: 10.3389/fpain.2023.1072786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/23/2023] [Indexed: 03/06/2023] Open
Abstract
Objectives This article presents a method-including hardware configuration, sampling rate, filtering settings, and other data analysis techniques-to measure evoked compound action potentials (ECAPs) during spinal cord stimulation (SCS) in humans with externalized percutaneous electrodes. The goal is to provide a robust and standardized protocol for measuring ECAPs on the non-stimulation contacts and to demonstrate how measured signals depend on hardware and processing decisions. Methods Two participants were implanted with percutaneous leads for the treatment of chronic pain with externalized leads during a trial period for stimulation and recording. The leads were connected to a Neuralynx ATLAS system allowing us to simultaneously stimulate and record through selected electrodes. We examined different hardware settings, such as online filters and sampling rate, as well as processing techniques, such as stimulation artifact removal and offline filters, and measured the effects on the ECAPs metrics: the first negative peak (N1) time and peak-valley amplitude. Results For accurate measurements of ECAPs, the hardware sampling rate should be least at 8 kHz and should use a high pass filter with a low cutoff frequency, such as 0.1 Hz, to eliminate baseline drift and saturation (railing). Stimulation artifact removal can use a double exponential or a second-order polynomial. The polynomial fit is 6.4 times faster on average in computation time than the double exponential, while the resulting ECAPs' N1 time and peak-valley amplitude are similar between the two. If the baseline raw measurement drifts with stimulation, a median filter with a 100-ms window or a high pass filter with an 80-Hz cutoff frequency preserves the ECAPs. Conclusions This work is the first comprehensive analysis of hardware and processing variations on the observed ECAPs from SCS leads. It sets recommendations to properly record and process ECAPs from the non-stimulation contacts on the implantable leads.
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Affiliation(s)
- Ahmed Ramadan
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Seth D. König
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, United States
| | - Mingming Zhang
- Clinical and Applied Research, Abbott Neuromodulation, Plano, TX, United States
- Correspondence: David P. Darrow Mingming Zhang
| | - Erika K. Ross
- Clinical and Applied Research, Abbott Neuromodulation, Plano, TX, United States
| | - Alexander Herman
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, United States
| | - Theoden I. Netoff
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - David P. Darrow
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States
- Correspondence: David P. Darrow Mingming Zhang
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Millar Vernetti P. Epidural Spinal Cord Stimulation to Treat Neurogenic Orthostatic Hypotension in Multiple System Atrophy: A New Hope? Mov Disord Clin Pract 2022; 9:1025-1026. [PMID: 36339315 PMCID: PMC9631845 DOI: 10.1002/mdc3.13583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/23/2022] [Indexed: 07/25/2023] Open
Affiliation(s)
- Patricio Millar Vernetti
- Department of Neurology, Dysautonomia CenterNew York University School of MedicineNew YorkNew YorkUSA
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Mao GW, Zhang JJ, Su H, Zhou ZJ, Zhu LS, Lü XY, Wang ZG. A flexible electrode array for determining regions of motor function activated by epidural spinal cord stimulation in rats with spinal cord injury. Neural Regen Res 2022; 17:601-607. [PMID: 34380900 PMCID: PMC8504402 DOI: 10.4103/1673-5374.320987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury. The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation. To activate lower-limb muscles precisely by epidural spinal cord stimulation, we proposed a high-density, flexible electrode array. We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord, which was established by a transection method. For evaluating the effect of stimulation, the evoked potentials were recorded from bilateral lower-limb muscles, including the vastus lateralis, semitendinosus, tibialis anterior, and medial gastrocnemius. To determine the appropriate stimulation sites and parameters of the lower muscles, the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation. In the vastus lateralis and medial gastrocnemius, these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment, respectively. The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles. The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius. Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array. They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury. This study was approved by the Animal Research Committee of Southeast University, China (approval No. 20190720001) on July 20, 2019.
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Affiliation(s)
- Guang-Wei Mao
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu Province, China
| | - Jian-Jun Zhang
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu Province, China
| | - Hao Su
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu Province, China
| | - Zhi-Jun Zhou
- Institute of RF- & OE-ICs, Southeast University, Nanjing, Jiangsu Province, China
| | - Lin-Sen Zhu
- Institute of RF- & OE-ICs, Southeast University, Nanjing, Jiangsu Province, China
| | - Xiao-Ying Lü
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zhi-Gong Wang
- Institute of RF- & OE-ICs, Southeast University, Nanjing; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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Gerasimenko Y, Preston C, Zhong H, Roy RR, Edgerton VR, Shah PK. Rostral lumbar segments are the key controllers of hindlimb locomotor rhythmicity in the adult spinal rat. J Neurophysiol 2019; 122:585-600. [PMID: 30943092 DOI: 10.1152/jn.00810.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The precise location and functional organization of the spinal neuronal locomotor-related networks in adult mammals remain unclear. Our recent neurophysiological findings provided empirical evidence that the rostral lumbar spinal cord segments play a critical role in the initiation and generation of the rhythmic activation patterns necessary for hindlimb locomotion in adult spinal rats. Since added epidural stimulation at the S1 segments significantly enhanced the motor output generated by L2 stimulation, these data also suggested that the sacral spinal cord provides a strong facilitory influence in rhythm initiation and generation. However, whether L2 will initiate hindlimb locomotion in the absence of S1 segments, and whether S1 segments can facilitate locomotion in the absence of L2 segments remain unknown. Herein, adult rats received complete spinal cord transections at T8 and then at either L2 or S1. Rats with spinal cord transections at T8 and S1 remained capable of generating coordinated hindlimb locomotion when receiving epidural stimulation at L2 and when ensembles of locomotor related loadbearing input were present. In contrast, minimal locomotion was observed when S1 stimulation was delivered after spinal cord transections at T8 and L2. Results were similar when the nonspecific serotonergic agonists were administered. These results demonstrate in adult rats that rostral lumbar segments are essential for the regulation of hindlimb locomotor rhythmicity. In addition, the more caudal spinal networks alone cannot control locomotion in the absence of the rostral segments around L2 even when loadbearing rhythmic proprioceptive afferent input is imposed.NEW & NOTEWORTHY The exact location of the spinal neuronal locomotor-related networks in adult mammals remains unknown. The present data demonstrate that when the rostral lumbar spinal segments (~L2) are completely eliminated in thoracic spinal adult rats, hindlimb stepping is not possible with neurochemical modulation of the lumbosacral cord. In contrast, eliminating the sacral cord retains stepping ability. These observations highlight the importance of rostral lumbar segments in generating effective mammalian locomotion.
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Affiliation(s)
- Yury Gerasimenko
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia.,Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Chet Preston
- Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, New York
| | - Hui Zhong
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Roland R Roy
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California.,Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, California.,Department of Neurosurgery, David Geffen School of Medicine at University of California, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, California.,Institute Guttmann. Hospital de Neurorehabilitació, Institut Universitari Adscrit a la Universitat Autònoma de Barcelona, Badalona, Spain.,Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.,Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Prithvi K Shah
- Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, New York.,Department of Neurobiology, Stony Brook University, Stony Brook, New York
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Walter M, Lee AHX, Kavanagh A, Phillips AA, Krassioukov AV. Epidural Spinal Cord Stimulation Acutely Modulates Lower Urinary Tract and Bowel Function Following Spinal Cord Injury: A Case Report. Front Physiol 2018; 9:1816. [PMID: 30618826 PMCID: PMC6305431 DOI: 10.3389/fphys.2018.01816] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/05/2018] [Indexed: 12/11/2022] Open
Abstract
Regaining control of autonomic functions such as those of the cardiovascular system, lower urinary tract and bowel, rank among the most important health priorities for individuals living with spinal cord injury (SCI). Recently our research provided evidence that epidural spinal cord stimulation (ESCS) could acutely modulate autonomic circuits responsible for cardiovascular function after SCI. This finding raised the question of whether ESCS can be used to modulate autonomic circuits involved in lower urinary tract and bowel control after SCI. We present the case of a 32-year-old man with a chronic motor-complete SCI (American Spinal injury Association Impairment Scale B) at the 5th cervical spinal segment. He sustained his injury during a diving accident in 2012. He was suffering from neurogenic lower urinary tract and bowel dysfunction. Epidural stimulation of the lumbosacral spinal cord immediately modulated both functions without negatively affecting the cardiovascular system. Specifically, the individual's bowel function was assessed using different pre-set configurations and stimulation parameters in a randomized order. Compared to the individual's conventional bowel management approach, ESCS significantly reduced the time needed for bowel management (p = 0.039). Furthermore, depending on electrode configuration and stimulation parameters (i.e., amplitude, frequency, and pulse width), ESCS modulated detrusor pressure and external anal sphincter/pelvic floor muscle tone to various degrees during urodynamic investigation. Although, ESCS is currently being explored primarily for restoring ambulation, our data suggest that application of this neuroprosthetic intervention may provide benefit to lower urinary tract and bowel function in individuals with SCI. To fully capitalize on the potential of improving lower urinary tract and bowel function, further research is needed to better understand the neuronal pathways and identify optimal stimulation configurations and parameters.
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Affiliation(s)
- Matthias Walter
- International Collaboration on Repair Discoveries, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Amanda H X Lee
- International Collaboration on Repair Discoveries, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Alex Kavanagh
- Department of Urologic Sciences, The University of British Columbia, Vancouver, BC, Canada
| | - Aaron A Phillips
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.,Division of Physical Medicine and Rehabilitation, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.,G.F. Strong Rehabilitation Centre, Vancouver, BC, Canada
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Hachmann JT, Calvert JS, Grahn PJ, Drubach DI, Lee KH, Lavrov IA. Review of Epidural Spinal Cord Stimulation for Augmenting Cough after Spinal Cord Injury. Front Hum Neurosci 2017; 11:144. [PMID: 28400726 PMCID: PMC5368218 DOI: 10.3389/fnhum.2017.00144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/13/2017] [Indexed: 12/13/2022] Open
Abstract
Spinal cord injury (SCI) remains a debilitating condition for which there is no cure. In addition to loss of somatic sensorimotor functions, SCI is also commonly associated with impairment of autonomic function. Importantly, cough dysfunction due to paralysis of expiratory muscles in combination with respiratory insufficiency can render affected individuals vulnerable to respiratory morbidity. Failure to clear sputum can aggravate both risk for and severity of respiratory infections, accounting for frequent hospitalizations and even mortality. Recently, epidural stimulation of the lower thoracic spinal cord has been investigated as novel means for restoring cough by evoking expiratory muscle contraction to generate large positive airway pressures and expulsive air flow. This review article discusses available preclinical and clinical evidence, current challenges and clinical potential of lower thoracic spinal cord stimulation (SCS) for restoring cough in individuals with SCI.
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Affiliation(s)
- Jan T Hachmann
- Department of Neurologic Surgery, Mayo Clinic Rochester, MN, USA
| | | | - Peter J Grahn
- Department of Neurologic Surgery, Mayo Clinic Rochester, MN, USA
| | - Dina I Drubach
- Department of Neurologic Surgery, Mayo Clinic Rochester, MN, USA
| | - Kendall H Lee
- Department of Neurologic Surgery, Mayo ClinicRochester, MN, USA; Department of Physiology and Biomedical Engineering, Mayo ClinicRochester, MN, USA; Department of Physical Medicine and Rehabilitation, Mayo ClinicRochester, MN, USA
| | - Igor A Lavrov
- Department of Neurologic Surgery, Mayo Clinic Rochester, MN, USA
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Pettigrew RI, Heetderks WJ, Kelley CA, Peng GC, Member IEEE, Krosnick SH, Jakeman LB, Egan KD, Marge M. Epidural Spinal Stimulation to Improve Bladder, Bowel, and Sexual Function in Individuals With Spinal Cord Injuries: A Framework for Clinical Research. IEEE Trans Biomed Eng 2017; 64:253-262. [PMID: 28113186 PMCID: PMC5513553 DOI: 10.1109/tbme.2016.2637301] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
While some recent studies that apply epidural spinal cord stimulation (SCS) have demonstrated a breakthrough in improvement of the health and quality of the life of persons with spinal cord injury (SCI), the numbers of people who have received SCS are small. This is in sharp contrast to the thousands of persons worldwide living with SCI who have no practical recourse or hope of recovery of lost functions. Thus, the vision is to understand the full potential of this new intervention and to determine if it is safe and effective in a larger cohort, and if it is scalable so that it can be made available to all those who might benefit. To achieve this vision, the National Institute of Biomedical Imaging and Bioengineering called for and organized a consortium of multiple stakeholder groups: foundations addressing paralysis, federal and public agencies, industrial partners, academicians, and researchers, all interested in the same goal. Based on input from consortium participants, we have reasoned that a first step is to define a scalable SCS approach that is effective in restoring lost autonomic physiology, specifically bladder, bowel, and sexual function. These functions are most critical for improving the quality of life of persons living with SCI. This report outlines a framework for conducting the research needed to define such an effective SCS procedure that might seek Food and Drug Administration approval and be implemented at the population level.
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Affiliation(s)
| | - William J. Heetderks
- Formerly with the National Institute of Biomedical Imaging and Bioengineering and is now employed by the Food and Drug Administration
| | - Christine A. Kelley
- Employees of the National Institute of Biomedical Imaging and Bioengineering
| | - Grace C.Y. Peng
- Employees of the National Institute of Biomedical Imaging and Bioengineering
| | - IEEE Member
- Employees of the National Institute of Biomedical Imaging and Bioengineering
| | - Steven H. Krosnick
- Employees of the National Institute of Biomedical Imaging and Bioengineering
| | - Lyn B. Jakeman
- Employee of the National Institute of Neurological Diseases and Stroke
| | - Katharine D. Egan
- Employees of the National Institute of Biomedical Imaging and Bioengineering
| | - Michael Marge
- Employees of the National Institute of Biomedical Imaging and Bioengineering
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12
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Danner SM, Hofstoetter US, Freundl B, Binder H, Mayr W, Rattay F, Minassian K. Human spinal locomotor control is based on flexibly organized burst generators. Brain 2015; 138:577-88. [PMID: 25582580 PMCID: PMC4408427 DOI: 10.1093/brain/awu372] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/01/2014] [Accepted: 11/05/2014] [Indexed: 12/27/2022] Open
Abstract
Constant drive provided to the human lumbar spinal cord by epidural electrical stimulation can cause local neural circuits to generate rhythmic motor outputs to lower limb muscles in people paralysed by spinal cord injury. Epidural spinal cord stimulation thus allows the study of spinal rhythm and pattern generating circuits without their configuration by volitional motor tasks or task-specific peripheral feedback. To reveal spinal locomotor control principles, we studied the repertoire of rhythmic patterns that can be generated by the functionally isolated human lumbar spinal cord, detected as electromyographic activity from the legs, and investigated basic temporal components shared across these patterns. Ten subjects with chronic, motor-complete spinal cord injury were studied. Surface electromyographic responses to lumbar spinal cord stimulation were collected from quadriceps, hamstrings, tibialis anterior, and triceps surae in the supine position. From these data, 10-s segments of rhythmic activity present in the four muscle groups of one limb were extracted. Such samples were found in seven subjects. Physiologically adequate cycle durations and relative extension- and flexion-phase durations similar to those needed for locomotion were generated. The multi-muscle activation patterns exhibited a variety of coactivation, mixed-synergy and locomotor-like configurations. Statistical decomposition of the electromyographic data across subjects, muscles and samples of rhythmic patterns identified three common temporal components, i.e. basic or shared activation patterns. Two of these basic patterns controlled muscles to contract either synchronously or alternatingly during extension- and flexion-like phases. The third basic pattern contributed to the observed muscle activities independently from these extensor- and flexor-related basic patterns. Each bifunctional muscle group was able to express both extensor- and flexor-patterns, with variable ratios across the samples of rhythmic patterns. The basic activation patterns can be interpreted as central drives implemented by spinal burst generators that impose specific spatiotemporally organized activation on the lumbosacral motor neuron pools. Our data thus imply that the human lumbar spinal cord circuits can form burst-generating elements that flexibly combine to obtain a wide range of locomotor outputs from a constant, repetitive input. It may be possible to use this flexibility to incorporate specific adaptations to gait and stance to improve locomotor control, even after severe central nervous system damage.
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Affiliation(s)
- Simon M Danner
- 1 Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria 2 Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ursula S Hofstoetter
- 2 Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Heinrich Binder
- 3 Neurological Centre, Otto Wagner Hospital, Vienna, Austria
| | - Winfried Mayr
- 2 Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Frank Rattay
- 1 Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Karen Minassian
- 2 Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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Golestanirad L, Elahi B, Molina A, Mosig JR, Pollo C, Chen R, Graham SJ. Analysis of fractal electrodes for efficient neural stimulation. Front Neuroeng 2013; 6:3. [PMID: 23874290 PMCID: PMC3709379 DOI: 10.3389/fneng.2013.00003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 06/06/2013] [Indexed: 11/17/2022]
Abstract
Planar electrodes are increasingly used in therapeutic neural stimulation techniques such as functional electrical stimulation, epidural spinal cord stimulation (ESCS), and cortical stimulation. Recently, optimized electrode geometries have been shown to increase the efficiency of neural stimulation by increasing the variation of current density on the electrode surface. In the present work, a new family of modified fractal electrode geometries is developed to enhance the efficiency of neural stimulation. It is shown that a promising approach in increasing the neural activation function is to increase the “edginess” of the electrode surface, a concept that is explained and quantified by fractal mathematics. Rigorous finite element simulations were performed to compute electric potential produced by proposed modified fractal geometries. The activation of 256 model axons positioned around the electrodes was then quantified, showing that modified fractal geometries required a 22% less input power while maintaining the same level of neural activation. Preliminary in vivo experiments investigating muscle evoked potentials due to median nerve stimulation showed encouraging results, supporting the feasibility of increasing neural stimulation efficiency using modified fractal geometries.
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Affiliation(s)
- Laleh Golestanirad
- Department of Physical Sciences, Sunnybrook Research Institute Toronto, Canada ; Department of Medical Biophysics, University of Toronto Toronto, Canada ; Laboratory of Electromagnetics and Acoustics, Electrical Engineering, Ecole Polytechnique Fédérale de Lausanne Lausanne, Switzerland
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