1
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Davids M, Vendramini L, Klein V, Ferris N, Guerin B, Wald LL. Experimental validation of a PNS-optimized whole-body gradient coil. Magn Reson Med 2024; 92:1788-1803. [PMID: 38767407 PMCID: PMC11262990 DOI: 10.1002/mrm.30157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/19/2024] [Accepted: 04/28/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE Peripheral nerve stimulation (PNS) limits the usability of state-of-the-art whole-body and head-only MRI gradient coils. We used detailed electromagnetic and neurodynamic modeling to set an explicit PNS constraint during the design of a whole-body gradient coil and constructed it to compare the predicted and experimentally measured PNS thresholds to those of a matched design without PNS constraints. METHODS We designed, constructed, and tested two actively shielded whole-body Y-axis gradient coil winding patterns: YG1 is a conventional symmetric design without PNS-optimization, whereas YG2's design used an additional constraint on the allowable PNS threshold in the head-imaging landmark, yielding an asymmetric winding pattern. We measured PNS thresholds in 18 healthy subjects at five landmark positions (head, cardiac, abdominal, pelvic, and knee). RESULTS The PNS-optimized design YG2 achieved 46% higher average experimental thresholds for a head-imaging landmark than YG1 while incurring a 15% inductance penalty. For cardiac, pelvic, and knee imaging landmarks, the PNS thresholds increased between +22% and +35%. For abdominal imaging, PNS thresholds did not change significantly between YG1 and YG2 (-3.6%). The agreement between predicted and experimental PNS thresholds was within 11.4% normalized root mean square error for both coils and all landmarks. The PNS model also produced plausible predictions of the stimulation sites when compared to the sites of perception reported by the subjects. CONCLUSION The PNS-optimization improved the PNS thresholds for the target scan landmark as well as most other studied landmarks, potentially yielding a significant improvement in image encoding performance that can be safely used in humans.
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Affiliation(s)
- Mathias Davids
- Martinos Center for Biomedical Imaging, Charlestown, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Livia Vendramini
- Martinos Center for Biomedical Imaging, Charlestown, MA, United States
| | - Valerie Klein
- Martinos Center for Biomedical Imaging, Charlestown, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Natalie Ferris
- Harvard Graduate Program in Biophysics, Harvard University, Cambridge, MA, United States
- Harvard-MIT Division of Health Sciences and Technology, Boston, MA, United States
| | - Bastien Guerin
- Martinos Center for Biomedical Imaging, Charlestown, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Lawrence L. Wald
- Martinos Center for Biomedical Imaging, Charlestown, MA, United States
- Harvard Medical School, Boston, MA, United States
- Harvard-MIT Division of Health Sciences and Technology, Boston, MA, United States
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2
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Takano K, Yamaguchi T, Kikuma K, Okuyama K, Katagiri N, Sato T, Tanabe S, Kondo K, Fujiwara T. Transcutaneous spinal cord stimulation phase-dependently modulates spinal reciprocal inhibition induced by pedaling in healthy individuals. Exp Brain Res 2024:10.1007/s00221-024-06926-4. [PMID: 39331051 DOI: 10.1007/s00221-024-06926-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Accepted: 09/09/2024] [Indexed: 09/28/2024]
Abstract
Reciprocal inhibition (RI) between leg muscles is crucial for smooth movement. Pedaling is a rhythmic movement that can increase RI in healthy individuals. Transcutaneous spinal cord stimulation (tSCS) stimulates spinal neural circuits by targeting the afferent fibers. Pedaling with simultaneous tSCS may modulate the plasticity of the spinal neural circuit and alter neural activity based on movement and muscle engagement. This study investigated the RI changes after pedaling and tSCS and determined the phase of pedaling in which tSCS should be applied for optimal RI modulation in healthy individuals. Eleven subjects underwent three interventions: pedaling combined with tSCS during the early phase of lower extension (phase 1), pedaling combined with tSCS during the late phase of lower flexion (phase 4) of the pedaling cycle, and pedaling combined with sham tSCS. The RI from the tibialis anterior to the soleus muscle was assessed before, immediately after, 15 min, and 30 min after the intervention. RI increased immediately after phase 4 and pedaling combined with sham tSCS, whereas no changes were observed after phase 1. These results demonstrate that tSCS modulates RI changes induced by pedaling in a stimulus phase-dependent manner in healthy individuals. However, the mechanism involved in this intervention needs to be explored to achieve higher efficacy.
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Affiliation(s)
- Keita Takano
- Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Tomofumi Yamaguchi
- Department of Physical Therapy, Juntendo University, Faculty of Health Science, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
- Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
| | - Kano Kikuma
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Kohei Okuyama
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Natsuki Katagiri
- Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Takatsugu Sato
- Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Shigeo Tanabe
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Aichi, Japan
| | - Kunitsugu Kondo
- Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Toshiyuki Fujiwara
- Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Department of Physical Therapy, Juntendo University, Faculty of Health Science, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
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3
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Hodgkiss DD, Williams AMM, Shackleton CS, Samejima S, Balthazaar SJT, Lam T, Krassioukov AV, Nightingale TE. Ergogenic effects of spinal cord stimulation on exercise performance following spinal cord injury. Front Neurosci 2024; 18:1435716. [PMID: 39268039 PMCID: PMC11390595 DOI: 10.3389/fnins.2024.1435716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Accepted: 08/05/2024] [Indexed: 09/15/2024] Open
Abstract
Cervical or upper-thoracic spinal cord injury (SCI, ≥T6) often leads to low resting blood pressure (BP) and impaired cardiovascular responses to acute exercise due to disrupted supraspinal sympathetic drive. Epidural spinal cord stimulation (invasive, ESCS) and transcutaneous spinal cord stimulation (non-invasive, TSCS) have previously been used to target dormant sympathetic circuits and modulate cardiovascular responses. This case series compared the effects of cardiovascular-optimised ESCS and TSCS versus sham ESCS and TSCS on modulating cardiovascular responses and improving submaximal upper-body exercise performance in individuals with SCI. Seven males with a chronic, motor-complete SCI between C6 and T4 underwent a mapping session to identify cardiovascular responses to spinal cord stimulation. Subsequently, four participants (two ESCS and two TSCS) completed submaximal exercise testing. Stimulation parameters (waveform, frequency, intensity, epidural electrode array configuration, and transcutaneous electrode locations in the lumbosacral region) were optimised to elevate cardiovascular responses (CV-SCS). A sham condition (SHAM-SCS) served as a comparison. Participants performed arm-crank exercise to exhaustion at a fixed workload corresponding to above ventilatory threshold, on separate days, with CV-SCS or SHAM-SCS. At rest, CV-SCS increased BP and predicted left ventricular cardiac contractility and total peripheral resistance. During exercise, CV-SCS increased time to exhaustion and peak oxygen pulse (a surrogate for stroke volume), relative to SHAM-SCS. Ratings of perceived exertion also tended to be lower with CV-SCS than SHAM-SCS. Comparable improvements in time to exhaustion with ESCS and TSCS suggest that both approaches could be promising ergogenic aids to support exercise performance or rehabilitation, along with reducing fatigue during activities of daily living in individuals with SCI.
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Affiliation(s)
- Daniel D Hodgkiss
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Alison M M Williams
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
| | - Claire S Shackleton
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Soshi Samejima
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, United States
| | - Shane J T Balthazaar
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Division of Cardiology, Department of Echocardiography, Vancouver General and St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Tania Lam
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
- GF Strong Rehabilitation Centre, Vancouver Coastal Health, Vancouver, BC, Canada
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
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4
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Huang Y, Yao K, Zhang Q, Huang X, Chen Z, Zhou Y, Yu X. Bioelectronics for electrical stimulation: materials, devices and biomedical applications. Chem Soc Rev 2024; 53:8632-8712. [PMID: 39132912 DOI: 10.1039/d4cs00413b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Bioelectronics is a hot research topic, yet an important tool, as it facilitates the creation of advanced medical devices that interact with biological systems to effectively diagnose, monitor and treat a broad spectrum of health conditions. Electrical stimulation (ES) is a pivotal technique in bioelectronics, offering a precise, non-pharmacological means to modulate and control biological processes across molecular, cellular, tissue, and organ levels. This method holds the potential to restore or enhance physiological functions compromised by diseases or injuries by integrating sophisticated electrical signals, device interfaces, and designs tailored to specific biological mechanisms. This review explains the mechanisms by which ES influences cellular behaviors, introduces the essential stimulation principles, discusses the performance requirements for optimal ES systems, and highlights the representative applications. From this review, we can realize the potential of ES based bioelectronics in therapy, regenerative medicine and rehabilitation engineering technologies, ranging from tissue engineering to neurological technologies, and the modulation of cardiovascular and cognitive functions. This review underscores the versatility of ES in various biomedical contexts and emphasizes the need to adapt to complex biological and clinical landscapes it addresses.
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Affiliation(s)
- Ya Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Kuanming Yao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Qiang Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Xingcan Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Zhenlin Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Yu Zhou
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Xinge Yu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
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5
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Veith DD, Gill ML, Beck LA, Whitmarsh CL, Fernandez KA, Linde MB, Asp AJ, Mills CJ, Bendel MA, Grahn PJ, Zhao KD. Functional outcomes and participants' perspectives during short-term application of spinal stimulation in individuals with spinal cord injury. J Spinal Cord Med 2024:1-12. [PMID: 39172032 DOI: 10.1080/10790268.2024.2383377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/23/2024] Open
Abstract
OBJECTIVE The primary objective of this study was to quantify changes in performance of task-specific motor activities over 12 motor rehabilitation sessions with lumbosacral spinal cord stimulation (SCS) via either transcutaneous stimulation or epidural stimulation. Both stimulation modalities have been used in recent years to restore functions lost to spinal cord injury (SCI). Secondary outcomes examine participants' perspectives captured via the User Experience Questionnaire (UEQ) upon study completion to further understand their perception of SCS. METHODS Six individuals with SCI completed 12 sessions with one modality of SCS during supine and/or side-lying, seated forward reaching, and standing activities. Changes in volitional lower extremity movement, the number of points of contact needed at hips and/or knees to facilitate standing, and changes in seated forward reaching distance were used to quantify performance. The UEQ was administered to gauge participants' perspectives following use of SCS to enable functions impaired due to SCI. RESULTS For all participants, performance of motor activities improved with SCS compared to without stimulation. Responses for the UEQ showed an overall positive perception of trialing SCS with rehabilitation to enhance motor functions impaired by SCI. CONCLUSIONS Regardless of injury severity, location of injury, time since SCI, or SCS modality, all participants experienced gains in motor function in the presence of SCS combined with a condensed rehabilitation program. However, no evidence of sustained motor functions was found in the absence of SCS. UEQ results highlight the positive perception of SCS with rehabilitation as well as the importance of consulting persons with lived experience of SCS during clinical trial design and protocol development.Trial registration: ClinicalTrials.gov identifier: NCT05095454.
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Affiliation(s)
- Daniel D Veith
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Megan L Gill
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Lisa A Beck
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Crystal L Whitmarsh
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - K A Fernandez
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester Minnesota, USA
| | - Margaux B Linde
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Anders J Asp
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Candee J Mills
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
| | - Mark A Bendel
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter J Grahn
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Kristin D Zhao
- Rehabilitation Medicine Research Center, Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester Minnesota, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
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6
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Keesey R, Hofstoetter U, Hu Z, Lombardi L, Hawthorn R, Bryson N, Rowald A, Minassian K, Seáñez I. FUNDAMENTAL LIMITATIONS OF KILOHERTZ-FREQUENCY CARRIERS IN AFFERENT FIBER RECRUITMENT WITH TRANSCUTANEOUS SPINAL CORD STIMULATION. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.26.603982. [PMID: 39211255 PMCID: PMC11361147 DOI: 10.1101/2024.07.26.603982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The use of kilohertz-frequency (KHF) waveforms has rapidly gained momentum in transcutaneous spinal cord stimulation (tSCS) to restore motor function after paralysis. However, the mechanisms by which these fast-alternating currents depolarize efferent and afferent fibers remain unknown. Our study fills this research gap by providing a hypothesis-and evidence-based investigation using peripheral nerve stimulation, lumbar tSCS, and cervical tSCS in 25 unimpaired participants together with computational modeling. Peripheral nerve stimulation experiments and computational modeling showed that KHF waveforms negatively impact the processes required to elicit action potentials, thereby increasing response thresholds and biasing the recruitment towards efferent fibers. While these results translate to tSCS, we also demonstrate that lumbar tSCS results in the preferential recruitment of afferent fibers, while cervical tSCS favors recruitment of efferent fibers. Given the assumed importance of proprioceptive afferents in motor recovery, our work suggests that the use of KHF waveforms should be reconsidered to maximize neurorehabilitation outcomes, particularly for cervical tSCS. We posit that careful analysis of the mechanisms that mediate responses elicited by novel approaches in tSCS is crucial to understanding their potential to restore motor function after paralysis.
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7
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Cuellar C, Lehto L, Islam R, Mangia S, Michaeli S, Lavrov I. Selective Activation of the Spinal Cord with Epidural Electrical Stimulation. Brain Sci 2024; 14:650. [PMID: 39061391 PMCID: PMC11274919 DOI: 10.3390/brainsci14070650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 06/22/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024] Open
Abstract
Spinal cord epidural electrical stimulation (EES) has been successfully employed to treat chronic pain and to restore lost functions after spinal cord injury. Yet, the efficacy of this approach is largely challenged by the suboptimal spatial distribution of the electrode contacts across anatomical targets, limiting the spatial selectivity of stimulation. In this study, we exploited different ESS paradigms, designed as either Spatial-Selective Stimulation (SSES) or Orientation-Selective Epidural Stimulation (OSES), and compared them to Conventional Monopolar Epidural Stimulation (CMES). SSES, OSES, and CMES were delivered with a 3- or 4-contact electrode array. Amplitudes and latencies of the Spinally Evoked Motor Potentials (SEMPs) were evaluated with different EES modalities. The results demonstrate that the amplitudes of SEMPs in hindlimb muscles depend on the orientation of the electrical field and vary between stimulation modalities. These findings show that the electric field applied with SSES or OSES provides more selective control of amplitudes of the SEMPs as compared to CMES. We demonstrate that spinal cord epidural stimulation applied with SSES or OSES paradigms in the rodent model could be tailored to the functional spinal cord neuroanatomy and can be tuned to specific target fibers and their orientation, optimizing the effect of neuromodulation.
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Affiliation(s)
- Carlos Cuellar
- School of Sport Sciences, Universidad Anáhuac México, Huixquilucan 52786, Mexico;
| | - Lauri Lehto
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA; (L.L.); (S.M.)
| | - Riaz Islam
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA;
| | - Silvia Mangia
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA; (L.L.); (S.M.)
| | - Shalom Michaeli
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA; (L.L.); (S.M.)
| | - Igor Lavrov
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA;
- Laboratory of Neuromodulation, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008 Kazan, Russia
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
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8
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Samejima S, Shackleton C, Miller T, Moritz CT, Kessler TM, Krogh K, Sachdeva R, Krassioukov AV. Mapping the Iceberg of Autonomic Recovery: Mechanistic Underpinnings of Neuromodulation following Spinal Cord Injury. Neuroscientist 2024; 30:378-389. [PMID: 36631741 PMCID: PMC11107126 DOI: 10.1177/10738584221145570] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Spinal cord injury leads to disruption in autonomic control resulting in cardiovascular, bowel, and lower urinary tract dysfunctions, all of which significantly reduce health-related quality of life. Although spinal cord stimulation shows promise for promoting autonomic recovery, the underlying mechanisms are unclear. Based on current preclinical and clinical evidence, this narrative review provides the most plausible mechanisms underlying the effects of spinal cord stimulation for autonomic recovery, including activation of the somatoautonomic reflex and induction of neuroplastic changes in the spinal cord. Areas where evidence is limited are highlighted in an effort to guide the scientific community to further explore these mechanisms and advance the clinical translation of spinal cord stimulation for autonomic recovery.
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Affiliation(s)
- Soshi Samejima
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Claire Shackleton
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Tiev Miller
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Chet T. Moritz
- Departments of Electrical and Computer Engineering, Rehabilitation Medicine, and Physiology and Biophysics and the Center for Neurotechnology, University of Washington, Seattle, WA, USA
| | - Thomas M. Kessler
- Department of Neuro-urology, Balgrist University Hospital, University of Zürich, Zürich, Switzerland
| | - Klaus Krogh
- Department of Clinical Medicine and Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Rahul Sachdeva
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Andrei V. Krassioukov
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
- Spinal Cord Program, GF Strong Rehabilitation Centre, Vancouver Coastal Health, Vancouver, Canada
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Yildiz N, Cecen S, Sancar N, Karacan I, Knikou M, Türker KS. Postsynaptic potentials of soleus motor neurons produced by transspinal stimulation: a human single-motor unit study. J Neurophysiol 2024; 131:1101-1111. [PMID: 38656134 PMCID: PMC11381115 DOI: 10.1152/jn.00077.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 04/26/2024] Open
Abstract
Transspinal (or transcutaneous spinal cord) stimulation is a noninvasive, cost-effective, easily applied method with great potential as a therapeutic modality for recovering somatic and nonsomatic functions in upper motor neuron disorders. However, how transspinal stimulation affects motor neuron depolarization is poorly understood, limiting the development of effective transspinal stimulation protocols for rehabilitation. In this study, we characterized the responses of soleus α motor neurons to single-pulse transspinal stimulation using single-motor unit (SMU) discharges as a proxy given the 1:1 discharge activation between the motor neuron and the motor unit. Peristimulus time histogram, peristimulus frequencygram, and surface electromyography (sEMG) were used to characterize the postsynaptic potentials of soleus motor neurons. Transspinal stimulation produced short-latency excitatory postsynaptic potentials (EPSPs) followed by two distinct phases of inhibitory postsynaptic potentials (IPSPs) in most soleus motor neurons and only IPSPs in others. Transspinal stimulation generated double discharges at short interspike intervals in a few motor units. The short-latency EPSPs were likely mediated by muscle spindle group Ia and II afferents, and the IPSPs via excitation of group Ib afferents and recurrent collaterals of motor neurons leading to activation of diverse spinal inhibitory interneuronal circuits. Further studies are warranted to understand better how transspinal stimulation affects depolarization of α motor neurons over multiple spinal segments. This knowledge will be seminal for developing effective transspinal stimulation protocols in upper motor neuron lesions.NEW & NOTEWORTHY Transspinal stimulation produces distinct actions on soleus motor neurons: an early short-latency excitation followed by two inhibitions or only inhibition and doublets. These results show how transspinal stimulation affects depolarization of soleus α motor neurons in healthy humans.
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Affiliation(s)
- Nilgün Yildiz
- Faculty of Dentistry & Physiology, Istanbul Gelisim University, Istanbul, Türkiye
- Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Istanbul Gelisim University, Istanbul, Türkiye
| | - Serpil Cecen
- Department of Physiology, Hamidiye Medical School, Health Science University, Istanbul, Türkiye
| | - Nuray Sancar
- Faculty of Dentistry & Physiology, Istanbul Gelisim University, Istanbul, Türkiye
| | - Ilhan Karacan
- Hamidiye Medical School, Physical Therapy Research and Education Hospital, Health Science University, Istanbul, Türkiye
| | - Maria Knikou
- Klab4Recovery Research Program, The City University of New York, New York, New York, United States
- Department of Physical Therapy, College of Staten Island, The City University of New York, New York, New York, United States
- PhD Program in Biology and Collaborative Neuroscience Program, Graduate Center of The City University of New York and College of Staten Island, New York, New York, United States
| | - Kemal S Türker
- Faculty of Dentistry & Physiology, Istanbul Gelisim University, Istanbul, Türkiye
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10
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Gordineer EA, Stokic DS, Krenn MJ. Distinguishing reflex from non-reflex responses elicited by transcutaneous spinal stimulation targeting the lumbosacral cord in healthy individuals. Exp Brain Res 2024:10.1007/s00221-024-06790-2. [PMID: 38416179 DOI: 10.1007/s00221-024-06790-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/21/2024] [Indexed: 02/29/2024]
Abstract
Transcutaneous spinal stimulation (TSS) studies rely on the depolarization of afferent fibers to provide input to the spinal cord; however, this has not been routinely ascertained. Thus, we aimed to characterize the types of responses evoked by TSS and establish paired-pulse ratio cutoffs that distinguish posterior root reflexes, evoked by stimulation of afferent nerve fibers, from motor responses, evoked by stimulation of efferent nerve fibers. Twelve neurologically intact participants (six women) underwent unipolar TSS (cathode over T11-12 spinal processes, anode paraumbilically) while resting supine. In six participants, unipolar TSS was repeated 2-3 months later and also compared to a bipolar TSS configuration (cathode 2.5 cm below T11-12, anode 5 cm above cathode). EMG signals were recorded from 16 leg muscles. A paired-pulse paradigm was applied at interstimulus intervals (ISIs) of 25, 50, 100, 200, and 400 ms. Responses were categorized by three assessors into reflexes, motor responses, or their combination (mixed responses) based on the visual presence/absence of paired-pulse suppression across ISIs. The paired-pulse ratio that best discriminated between response types was derived for each ISI. These cutoffs were validated by repeating unipolar TSS 2-3 months later and with bipolar TSS. Unipolar TSS evoked only reflexes (90%) and mixed responses (10%), which were mainly recorded in the quadriceps muscles (25-42%). Paired-pulse ratios of 0.51 (25-ms ISI) and 0.47 (50-ms ISI) best distinguished reflexes from mixed responses (100% sensitivity, > 99.2% specificity). These cutoffs performed well in the repeated unipolar TSS session (100% sensitivity, > 89% specificity). Bipolar TSS exclusively elicited reflexes which were all correctly classified. These results can be utilized in future studies to ensure that the input to the spinal cord originates from the depolarization of large afferents. This knowledge can be applied to improve the design of future neurophysiological studies and increase the fidelity of neuromodulation interventions.
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Affiliation(s)
- Elizabeth A Gordineer
- School of Graduate Studies in the Health Sciences, Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, USA
- Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, Jackson, MS, USA
| | - Dobrivoje S Stokic
- Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, Jackson, MS, USA
| | - Matthias J Krenn
- Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, Jackson, MS, USA.
- Department of Neurosurgery, University of Mississippi Medical Center, 2500 N State St, Jackson, MS, 39216, USA.
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11
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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] [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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12
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Mickle AR, Peñaloza-Aponte JD, Coffey R, Hall NA, Baekey D, Dale EA. Closed-loop cervical epidural stimulation partially restores ipsilesional diaphragm EMG after acute C 2 hemisection. Respir Physiol Neurobiol 2024; 320:104182. [PMID: 37923238 PMCID: PMC11135909 DOI: 10.1016/j.resp.2023.104182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/22/2023] [Accepted: 10/22/2023] [Indexed: 11/07/2023]
Abstract
Cervical spinal cord injury creates lasting respiratory deficits which can require mechanical ventilation long-term. We have shown that closed-loop epidural stimulation (CL-ES) elicits respiratory plasticity in the form of increased phrenic network excitability (Malone et. al., E Neuro, Vol 9, 0426-21.2021, 2022); however, the ability of this treatment to create functional benefits for breathing function per se after injury has not been demonstrated. Here, we demonstrate in C2 hemisected anesthetized rats, a 20-minute bout of CL-ES administered at current amplitudes below the motor threshold restores paralyzed hemidiaphragm activity in-phase with breathing while potentiating contralesional activity. While this acute bout of stimulation did not elicit the increased network excitability seen in our chronic model, a subset of stimulated animals continued spontaneous ipsilesional diaphragm activity for several seconds after stopping stimulation. These results support the use of CL-ES as a therapeutic to rescue breathing after high cervical spinal cord injury, with the potential to lead to lasting recovery and device independence.
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Affiliation(s)
- Alyssa R Mickle
- Department of Neuroscience, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; Breathing Research and Therapeutics Center, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; McKnight Brain Institute, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States.
| | - Jesús D Peñaloza-Aponte
- Department of Neuroscience, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; Breathing Research and Therapeutics Center, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; McKnight Brain Institute, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States
| | - Richard Coffey
- Department of Physiology and Aging, University of Florida, 1600 SW Archer Rd M552, Gainesville, FL 32603, United States
| | - Natale A Hall
- Department of Physiology and Aging, University of Florida, 1600 SW Archer Rd M552, Gainesville, FL 32603, United States
| | - David Baekey
- Department of Neuroscience, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; Breathing Research and Therapeutics Center, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; McKnight Brain Institute, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States
| | - Erica A Dale
- Department of Neuroscience, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; Breathing Research and Therapeutics Center, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; McKnight Brain Institute, University of Florida, 1149 Newell Dr, Gainesville, FL 32610, United States; Department of Physiology and Aging, University of Florida, 1600 SW Archer Rd M552, Gainesville, FL 32603, United States
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13
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Mukhametova E, Militskova A, Biktimirov A, Kharin N, Semenova E, Sachenkov O, Baltina T, Lavrov I. Consecutive Transcutaneous and Epidural Spinal Cord Neuromodulation to Modify Clinical Complete Paralysis-the Proof of Concept. Mayo Clin Proc Innov Qual Outcomes 2024; 8:1-16. [PMID: 38186923 PMCID: PMC10770429 DOI: 10.1016/j.mayocpiqo.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024] Open
Abstract
Objective To evaluate the effect of transcutaneous (tSCS) and epidural electrical spinal cord stimulation (EES) in facilitating volitional movements, balance, and nonmotor functions, in this observational study, tSCS and EES were consecutively tested in 2 participants with motor complete spinal cord injury (SCI). Participants and Methods Two participants (a 48-year-old woman and a 28-year-old man), both classified as motor complete spinal injury, were enrolled in the study. Both participants went through a unified protocol, such as an initial electrophysiological assessment of neural connectivity, consecutive tSCS and EES combined with 8 wks of motor training with electromyography (EMG) and kinematic evaluation. The study was conducted from May 1, 2019, to December 31, 2021. Results In both participants, tSCS reported a minimal improvement in voluntary movements still essential to start tSCS-enabled rehabilitation. Compared with tSCS, following EES showed immediate improvement in voluntary movements, whereas tSCS was more effective in improving balance and posture. Continuous improvement in nonmotor functions was found during tSCS-enabled and then during EES-enabled motor training. Conclusion Results report a significant difference in the effect of tSCS and EES on the recovery of neurologic functions and support consecutive tSCS and EES applications as a potential therapy for SCI. The proposed approach may help in selecting patients with SCI responsive to neuromodulation. It would also help initiate neuromodulation and rehabilitation therapy early, particularly for motor complete SCI with minimal effect from conventional rehabilitation.
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Affiliation(s)
- Elvira Mukhametova
- Department of Neurology, Department of Biomedical Engineering, Mayo Clinic, Rochester, MN
- Laboratory of Neuromodulation, Kazan Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russia
- Laboratory of Movement Physiology, Federal State Institution of Science Institute of Physiology, IP Pavlov, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Alena Militskova
- Department of Neurology, Department of Biomedical Engineering, Mayo Clinic, Rochester, MN
- Laboratory of Neuromodulation, Kazan Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russia
- Laboratory of Movement Physiology, Federal State Institution of Science Institute of Physiology, IP Pavlov, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Artur Biktimirov
- Center of Neurotechnologies, Virtual, and Augmented Reality Technologies, Department of Neurosurgery, Far Eastern Federal University, Russia
| | - Nikita Kharin
- Laboratory of Shell Mechanics, N.I. Lobachevsky Institute of Mathematics and Mechanics, Kazan Federal University, Kazan, Russia
| | - Elena Semenova
- Laboratory of Shell Mechanics, N.I. Lobachevsky Institute of Mathematics and Mechanics, Kazan Federal University, Kazan, Russia
| | - Oskar Sachenkov
- Laboratory of Shell Mechanics, N.I. Lobachevsky Institute of Mathematics and Mechanics, Kazan Federal University, Kazan, Russia
| | - Tatiana Baltina
- Laboratory of Neuromodulation, Kazan Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russia
| | - Igor Lavrov
- Department of Neurology, Department of Biomedical Engineering, Mayo Clinic, Rochester, MN
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14
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Spieker EL, Dvorani A, Salchow-Hömmen C, Otto C, Ruprecht K, Wenger N, Schauer T. Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography. SENSORS (BASEL, SWITZERLAND) 2024; 24:634. [PMID: 38276326 PMCID: PMC10818383 DOI: 10.3390/s24020634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/14/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024]
Abstract
Transcutaneous spinal cord stimulation (tSCS) provides a promising therapy option for individuals with injured spinal cords and multiple sclerosis patients with spasticity and gait deficits. Before the therapy, the examiner determines a suitable electrode position and stimulation current for a controlled application. For that, amplitude characteristics of posterior root muscle (PRM) responses in the electromyography (EMG) of the legs to double pulses are examined. This laborious procedure holds potential for simplification due to time-consuming skin preparation, sensor placement, and required expert knowledge. Here, we investigate mechanomyography (MMG) that employs accelerometers instead of EMGs to assess muscle activity. A supervised machine-learning classification approach was implemented to classify the acceleration data into no activity and muscular/reflex responses, considering the EMG responses as ground truth. The acceleration-based calibration procedure achieved a mean accuracy of up to 87% relative to the classical EMG approach as ground truth on a combined cohort of 11 healthy subjects and 11 patients. Based on this classification, the identified current amplitude for the tSCS therapy was in 85%, comparable to the EMG-based ground truth. In healthy subjects, where both therapy current and position have been identified, 91% of the outcome matched well with the EMG approach. We conclude that MMG has the potential to make the tuning of tSCS feasible in clinical practice and even in home use.
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Affiliation(s)
- Eira Lotta Spieker
- Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.L.S.); (C.S.-H.); (C.O.); (K.R.); (N.W.)
- Control Systems Group, Technische Universität Berlin, Einsteinufer 17, 10587 Berlin, Germany;
- SensorStim Neurotechnology GmbH, c/o TU Berlin, Einsteinufer 17, 10587 Berlin, Germany
| | - Ardit Dvorani
- Control Systems Group, Technische Universität Berlin, Einsteinufer 17, 10587 Berlin, Germany;
- SensorStim Neurotechnology GmbH, c/o TU Berlin, Einsteinufer 17, 10587 Berlin, Germany
| | - Christina Salchow-Hömmen
- Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.L.S.); (C.S.-H.); (C.O.); (K.R.); (N.W.)
| | - Carolin Otto
- Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.L.S.); (C.S.-H.); (C.O.); (K.R.); (N.W.)
| | - Klemens Ruprecht
- Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.L.S.); (C.S.-H.); (C.O.); (K.R.); (N.W.)
| | - Nikolaus Wenger
- Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.L.S.); (C.S.-H.); (C.O.); (K.R.); (N.W.)
| | - Thomas Schauer
- Control Systems Group, Technische Universität Berlin, Einsteinufer 17, 10587 Berlin, Germany;
- SensorStim Neurotechnology GmbH, c/o TU Berlin, Einsteinufer 17, 10587 Berlin, Germany
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15
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Mundra A, Varma Kalidindi K, Chhabra HS, Manghwani J. Spinal cord stimulation for spinal cord injury - Where do we stand? A narrative review. J Clin Orthop Trauma 2023; 43:102210. [PMID: 37663171 PMCID: PMC10470322 DOI: 10.1016/j.jcot.2023.102210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/14/2023] [Accepted: 06/29/2023] [Indexed: 09/05/2023] Open
Abstract
Recovery of function following a complete spinal cord injury (SCI) or an incomplete SCI where recovery has plateaued still eludes us despite extensive research. Epidural spinal cord stimulation (SCS) was initially used for managing neuropathic pain. It has subsequently demonstrated improvement in motor function in otherwise non-recovering chronic spinal cord injury in animal and human trials. The mechanisms of how it is precisely effective in doing so will need further research, which would help refine the technology for broader application. Transcutaneous spinal cord stimulation (TSCS) is also emerging as a modality to improve the functional outcome in SCI individuals, especially when coupled with appropriate rehabilitation. Apart from motor recovery, ESCS and TSCS have also shown improvement in autonomic, metabolic, genitourinary, and pulmonary function. Since the literature on this is still in its infancy, with no large-scale randomised trials and different studies using different protocols in a wide range of patients, a review of the present literature is imperative to better understand the latest developments in this field. This article examines the existing literature on the use of SCS for SCI individuals with the purpose of enabling functional recovery. It also examines the voids in the present research, thus providing future directions.
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Affiliation(s)
- Anuj Mundra
- Department of Spine and Rehabilitation, Sri Balaji Action Medical Institute, New Delhi, 110063, India
| | | | - Harvinder Singh Chhabra
- Department of Spine and Rehabilitation, Sri Balaji Action Medical Institute, New Delhi, 110063, India
| | - Jitesh Manghwani
- Indian Spinal Injuries Centre, Vasant Kunj, New Delhi, 110070, India
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16
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Bryson N, Lombardi L, Hawthorn R, Fei J, Keesey R, Peiffer J, Seáñez I. Enhanced selectivity of transcutaneous spinal cord stimulation by multielectrode configuration. J Neural Eng 2023; 20:10.1088/1741-2552/ace552. [PMID: 37419109 PMCID: PMC10481387 DOI: 10.1088/1741-2552/ace552] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/07/2023] [Indexed: 07/09/2023]
Abstract
Objective.Transcutaneous spinal cord stimulation (tSCS) has been gaining momentum as a non-invasive rehabilitation approach to restore movement to paralyzed muscles after spinal cord injury (SCI). However, its low selectivity limits the types of movements that can be enabled and, thus, its potential applications in rehabilitation.Approach.In this cross-over study design, we investigated whether muscle recruitment selectivity of individual muscles could be enhanced by multielectrode configurations of tSCS in 16 neurologically intact individuals. We hypothesized that due to the segmental innervation of lower limb muscles, we could identify muscle-specific optimal stimulation locations that would enable improved recruitment selectivity over conventional tSCS. We elicited leg muscle responses by delivering biphasic pulses of electrical stimulation to the lumbosacral enlargement using conventional and multielectrode tSCS.Results.Analysis of recruitment curve responses confirmed that multielectrode configurations could improve the rostrocaudal and lateral selectivity of tSCS. To investigate whether motor responses elicited by spatially selective tSCS were mediated by posterior root-muscle reflexes, each stimulation event was a paired pulse with a conditioning-test interval of 33.3 ms. Muscle responses to the second stimulation pulse were significantly suppressed, a characteristic of post-activation depression suggesting that spatially selective tSCS recruits proprioceptive fibers that reflexively activate muscle-specific motor neurons in the spinal cord. Moreover, the combination of leg muscle recruitment probability and segmental innervation maps revealed a stereotypical spinal activation map in congruence with each electrode's position.Significance. Improvements in muscle recruitment selectivity could be essential for the effective translation into stimulation protocols that selectively enhance single-joint movements in neurorehabilitation.
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Affiliation(s)
- Noah Bryson
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
| | - Lorenzo Lombardi
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
| | - Rachel Hawthorn
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
| | - Jie Fei
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
| | - Rodolfo Keesey
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
| | - J.D. Peiffer
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
- Biomedical Engineering, Northwestern University
| | - Ismael Seáñez
- Biomedical Engineering, Washington University in St. Louis
- Division of Neurotechnology, Washington University School of Medicine in St. Louis
- Neurosurgery, Washington University School of Medicine in St. Louis
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17
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Chandrasekaran S, Bhagat NA, Ramdeo R, Ebrahimi S, Sharma PD, Griffin DG, Stein A, Harkema SJ, Bouton CE. Targeted transcutaneous spinal cord stimulation promotes persistent recovery of upper limb strength and tactile sensation in spinal cord injury: a pilot study. Front Neurosci 2023; 17:1210328. [PMID: 37483349 PMCID: PMC10360050 DOI: 10.3389/fnins.2023.1210328] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 06/15/2023] [Indexed: 07/25/2023] Open
Abstract
Long-term recovery of limb function is a significant unmet need in people with paralysis. Neuromodulation of the spinal cord through epidural stimulation, when paired with intense activity-based training, has shown promising results toward restoring volitional limb control in people with spinal cord injury. Non-invasive neuromodulation of the cervical spinal cord using transcutaneous spinal cord stimulation (tSCS) has shown similar improvements in upper-limb motor control rehabilitation. However, the motor and sensory rehabilitative effects of activating specific cervical spinal segments using tSCS have largely remained unexplored. We show in two individuals with motor-complete SCI that targeted stimulation of the cervical spinal cord resulted in up to a 1,136% increase in exerted force, with weekly activity-based training. Furthermore, this is the first study to document up to a 2-point improvement in clinical assessment of tactile sensation in SCI after receiving tSCS. Lastly, participant gains persisted after a one-month period void of stimulation, suggesting that targeted tSCS may lead to persistent recovery of motor and sensory function.
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Affiliation(s)
- Santosh Chandrasekaran
- Neural Bypass and Brain Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Nikunj A. Bhagat
- Neural Bypass and Brain Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center, Houston, TX, United States
| | - Richard Ramdeo
- Neural Bypass and Brain Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Sadegh Ebrahimi
- Neural Bypass and Brain Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Pawan D. Sharma
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States
| | - Doug G. Griffin
- Northwell Health STARS Rehabilitation, East Meadow, NY, United States
| | - Adam Stein
- Department of Physical Medicine and Rehabilitation, Donald and Barbara Zucker School of Medicine at Hofstra, Northwell Health, Manhasset, NY, United States
| | - Susan J. Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States
- Department of Bioengineering, University of Louisville, Louisville, KY, United States
- Frazier Rehabilitation Institute, University of Louisville Health, Louisville, KY, United States
- Department of Neurological Surgery, University of Louisville, Louisville, KY, United States
| | - Chad E. Bouton
- Neural Bypass and Brain Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY, United States
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18
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Calvert JS, Darie R, Parker SR, Shaaya E, Syed S, McLaughlin BL, Fridley JS, Borton DA. Spatiotemporal Distribution of Electrically Evoked Spinal Compound Action Potentials During Spinal Cord Stimulation. Neuromodulation 2023; 26:961-974. [PMID: 35551869 PMCID: PMC9643656 DOI: 10.1016/j.neurom.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/07/2022] [Accepted: 03/23/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Recent studies using epidural spinal cord stimulation (SCS) have demonstrated restoration of motor function in individuals previously diagnosed with chronic spinal cord injury (SCI). In parallel, the spinal evoked compound action potentials (ECAPs) induced by SCS have been used to gain insight into the mechanisms of SCS-based chronic pain therapy and to titrate closed-loop delivery of stimulation. However, the previous characterization of ECAPs recorded during SCS was performed with one-dimensional, cylindrical electrode leads. Herein, we describe the unique spatiotemporal distribution of ECAPs induced by SCS across the medial-lateral and rostral-caudal axes of the spinal cord, and their relationship to polysynaptic lower-extremity motor activation. MATERIALS AND METHODS In each of four sheep, two 24-contact epidural SCS arrays were placed on the lumbosacral spinal cord, spanning the L3 to L6 vertebrae. Spinal ECAPs were recorded during SCS from nonstimulating contacts of the epidural arrays, which were synchronized to bilateral electromyography (EMG) recordings from six back and lower-extremity muscles. RESULTS We observed a triphasic P1, N1, P2 peak morphology and propagation in the ECAPs during midline and lateral stimulation. Distinct regions of lateral stimulation resulted in simultaneously increased ECAP and EMG responses compared with stimulation at adjacent lateral contacts. Although EMG responses decreased during repetitive stimulation bursts, spinal ECAP amplitude did not significantly change. Both spinal ECAP responses and EMG responses demonstrated preferential ipsilateral recruitment during lateral stimulation compared with midline stimulation. Furthermore, EMG responses were correlated with stimulation that resulted in increased ECAP amplitude on the ipsilateral side of the electrode array. CONCLUSIONS These results suggest that ECAPs can be used to investigate the effects of SCS on spinal sensorimotor networks and to inform stimulation strategies that optimize the clinical benefit of SCS in the context of managing chronic pain and the restoration of sensorimotor function after SCI.
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Affiliation(s)
- Jonathan S Calvert
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Radu Darie
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Samuel R Parker
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Elias Shaaya
- Department of Neurosurgery, Brown University and Rhode Island Hospital, Providence, RI, USA
| | - Sohail Syed
- Department of Neurosurgery, Brown University and Rhode Island Hospital, Providence, RI, USA
| | | | - Jared S Fridley
- Department of Neurosurgery, Brown University and Rhode Island Hospital, Providence, RI, USA
| | - David A Borton
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA; Department of Veterans Affairs, Center for Neurorestoration and Neurotechnology, Providence, RI, USA; Carney Institute for Brain Science, Brown University, Providence, RI, USA.
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19
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Finn HT, Bye EA, Elphick TG, Boswell-Ruys CL, Gandevia SC, Butler JE, Héroux ME. Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity. Physiol Rep 2023; 11:e15692. [PMID: 37269156 PMCID: PMC10238786 DOI: 10.14814/phy2.15692] [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: 04/21/2023] [Accepted: 05/03/2023] [Indexed: 06/04/2023] Open
Abstract
Transcutaneous spinal cord stimulation (TSS) is purported to improve motor function in people after spinal cord injury (SCI). However, several methodology aspects are yet to be explored. We investigated whether stimulation configuration affected the intensity needed to elicit spinally evoked motor responses (sEMR) in four lower limb muscles bilaterally. Also, since stimulation intensity for therapeutic TSS (i.e., trains of stimulation, typically delivered at 15-50 Hz) is sometimes based on the single-pulse threshold intensity, we compared these two stimulation types. In non-SCI participants (n = 9) and participants with a SCI (n = 9), three different electrode configurations (cathode-anode); L1-midline (below the umbilicus), T11-midline and L1-ASIS (anterior superior iliac spine; non-SCI only) were compared for the sEMR threshold intensity using single pulses or trains of stimulation which were recorded in the vastus medialis, medial hamstring, tibialis anterior, medial gastrocnemius muscles. In non-SCI participants, the L1-midline configuration showed lower sEMR thresholds compared to T11-midline (p = 0.002) and L1-ASIS (p < 0.001). There was no difference between T11-midline and L1-midline for participants with SCI (p = 0.245). Spinally evoked motor response thresholds were ~13% lower during trains of stimulation compared to single pulses in non-SCI participants (p < 0.001), but not in participants with SCI (p = 0.101). With trains of stimulation, threshold intensities were slightly lower and the incidence of sEMR was considerably lower. Overall, stimulation threshold intensities were generally lower with the L1-midline electrode configuration and is therefore preferred. While single-pulse threshold intensities may overestimate threshold intensities for therapeutic TSS, tolerance to trains of stimulation will be the limiting factor in most cases.
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Affiliation(s)
- Harrison T Finn
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
| | - Elizabeth A Bye
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
- Prince of Wales Hospital, Randwick, New South Wales, Australia
| | - Thomas G Elphick
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
| | - Claire L Boswell-Ruys
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
- Prince of Wales Hospital, Randwick, New South Wales, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Prince of Wales Hospital, Randwick, New South Wales, Australia
- School of Clinical Medicine, University of New South Wales, New South Wales, Kensington, Australia
| | - Jane E Butler
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
| | - Martin E Héroux
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, New South Wales, Kensington, Australia
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Bryson N, Lombardi L, Hawthorn R, Fei J, Keesey R, Peiffer JD, Seáñez I. Enhanced selectivity of transcutaneous spinal cord stimulation by multielectrode configuration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.30.534835. [PMID: 37034788 PMCID: PMC10081184 DOI: 10.1101/2023.03.30.534835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Objective Transcutaneous spinal cord stimulation (tSCS) has been gaining momentum as a non-invasive rehabilitation approach to restore movement to paralyzed muscles after spinal cord injury (SCI). However, its low selectivity limits the types of movements that can be enabled and, thus, its potential applications in rehabilitation. Approach In this cross-over study design, we investigated whether muscle recruitment selectivity of individual muscles could be enhanced by multielectrode configurations of tSCS in 16 neurologically intact individuals. We hypothesized that due to the segmental innervation of lower limb muscles, we could identify muscle-specific optimal stimulation locations that would enable improved recruitment selectivity over conventional tSCS. We elicited leg muscle responses by delivering biphasic pulses of electrical stimulation to the lumbosacral enlargement using conventional and multielectrode tSCS. Results Analysis of recruitment curve responses confirmed that multielectrode configurations could improve the rostrocaudal and lateral selectivity of tSCS. To investigate whether motor responses elicited by spatially selective tSCS were mediated by posterior root-muscle reflexes, each stimulation event was a paired pulse with a conditioning-test interval of 33.3 ms. Muscle responses to the second stimulation pulse were significantly suppressed, a characteristic of post-activation depression suggesting that spatially selective tSCS recruits proprioceptive fibers that reflexively activate muscle-specific motor neurons in the spinal cord. Moreover, the combination of leg muscle recruitment probability and segmental innervation maps revealed a stereotypical spinal activation map in congruence with each electrode's position. Significance Improvements in muscle recruitment selectivity could be essential for the effective translation into stimulation protocols that selectively enhance single-joint movements in neurorehabilitation.
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21
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Skiadopoulos A, Pulverenti TS, Knikou M. Physiological effects of cathodal electrode configuration for transspinal stimulation in humans. J Neurophysiol 2022; 128:1663-1682. [PMID: 36416443 PMCID: PMC9762966 DOI: 10.1152/jn.00342.2022] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/24/2022] Open
Abstract
Transspinal stimulation modulates neuronal excitability and promotes recovery in upper motoneuron lesions. The recruitment input-output curves of transspinal evoked potentials (TEPs) recorded from knee and ankle muscles, and their susceptibility to spinal inhibition, were recorded when the position, size, and number of the cathode electrode were arranged in four settings or protocols (Ps). The four Ps were the following: 1) one rectangular electrode placed at midline (KNIKOU-LAB4Recovery or K-LAB4Recovery; P-KLAB), 2) one square electrode placed at midline (P-2), 3) two square electrodes 1 cm apart placed at midline (P-3), and 4) one square electrode placed on each paravertebral side (P-4). P-KLAB and P-3 required less current to reach TEP threshold or maximal amplitudes. A rightward shift in TEP recruitment curves was evident for P-4, whereas the slope was increased for P-2 and P-4 compared with P-KLAB and P-3. TEP depression upon single and paired transspinal stimuli was pronounced in ankle TEPs but was less prominent in knee TEPs. TEP depression induced by single transspinal stimuli at 1.0 Hz was similar for most TEPs across protocols, but TEP depression induced by paired transspinal stimuli was different between protocols and was replaced by facilitation at 100-ms interstimulus interval for P-4. Our results suggest that P-KLAB and P-3 are preferred based on excitability threshold of motoneurons. P-KLAB produced more TEP depression, thereby maximizing the engagement of spinal neuronal pathways. We recommend P-KLAB to study neurophysiological mechanisms underlying transspinal stimulation or when used as a neuromodulation method for recovery in neurological disorders.NEW & NOTEWORTHY Transspinal stimulation with a rectangular cathode electrode (P-KLAB) requires less current to produce transspinal evoked potentials and maximizes spinal inhibition. We recommend P-KLAB for neurophysiological studies or when used as a neuromodulation method to enhance motor output and normalize muscle tone in neurological disorders.
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Affiliation(s)
- Andreas Skiadopoulos
- Klab4Recovery Research Program, The City University of New York, New York, New York
| | - Timothy S Pulverenti
- Klab4Recovery Research Program, The City University of New York, New York, New York
| | - Maria Knikou
- Klab4Recovery Research Program, The City University of New York, New York, New York
- Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York
- PhD Program in Biology and Collaborative Neuroscience Program, Graduate Center of The City University of New York and College of Staten Island, Staten Island, New York
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22
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Govindarajan LN, Calvert JS, Parker SR, Jung M, Darie R, Miranda P, Shaaya E, Borton DA, Serre T. Fast inference of spinal neuromodulation for motor control using amortized neural networks. J Neural Eng 2022; 19:10.1088/1741-2552/ac9646. [PMID: 36174534 PMCID: PMC9668352 DOI: 10.1088/1741-2552/ac9646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/29/2022] [Indexed: 11/12/2022]
Abstract
Objective.Epidural electrical stimulation (EES) has emerged as an approach to restore motor function following spinal cord injury (SCI). However, identifying optimal EES parameters presents a significant challenge due to the complex and stochastic nature of muscle control and the combinatorial explosion of possible parameter configurations. Here, we describe a machine-learning approach that leverages modern deep neural networks to learn bidirectional mappings between the space of permissible EES parameters and target motor outputs.Approach.We collected data from four sheep implanted with two 24-contact EES electrode arrays on the lumbosacral spinal cord. Muscle activity was recorded from four bilateral hindlimb electromyography (EMG) sensors. We introduce a general learning framework to identify EES parameters capable of generating desired patterns of EMG activity. Specifically, we first amortize spinal sensorimotor computations in a forward neural network model that learns to predict motor outputs based on EES parameters. Then, we employ a second neural network as an inverse model, which reuses the amortized knowledge learned by the forward model to guide the selection of EES parameters.Main results.We found that neural networks can functionally approximate spinal sensorimotor computations by accurately predicting EMG outputs based on EES parameters. The generalization capability of the forward model critically benefited our inverse model. We successfully identified novel EES parameters, in under 20 min, capable of producing desired target EMG recruitment duringin vivotesting. Furthermore, we discovered potential functional redundancies within the spinal sensorimotor networks by identifying unique EES parameters that result in similar motor outcomes. Together, these results suggest that our framework is well-suited to probe spinal circuitry and control muscle recruitment in a completely data-driven manner.Significance.We successfully identify novel EES parameters within minutes, capable of producing desired EMG recruitment. Our approach is data-driven, subject-agnostic, automated, and orders of magnitude faster than manual approaches.
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Affiliation(s)
- Lakshmi Narasimhan Govindarajan
- Cognitive, Linguistic & Psychological Sciences, Brown University, Providence RI USA
- Carney Institute for Brain Science, Brown University, Providence RI USA
| | | | | | - Minju Jung
- Cognitive, Linguistic & Psychological Sciences, Brown University, Providence RI USA
- Carney Institute for Brain Science, Brown University, Providence RI USA
| | - Radu Darie
- School of Engineering, Brown University, Providence RI USA
| | | | - Elias Shaaya
- Department of Neurosurgery, Brown University and Rhode Island Hospital, Providence RI USA
| | - David A. Borton
- Carney Institute for Brain Science, Brown University, Providence RI USA
- School of Engineering, Brown University, Providence RI USA
- Center for Neurorestoration and Neurotechnology, Department of Veterans Affairs, Providence RI USA
| | - Thomas Serre
- Cognitive, Linguistic & Psychological Sciences, Brown University, Providence RI USA
- Carney Institute for Brain Science, Brown University, Providence RI USA
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23
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Pirondini E, Carranza E, Balaguer JM, Sorensen E, Weber DJ, Krakauer JW, Capogrosso M. Poststroke arm and hand paresis: should we target the cervical spinal cord? Trends Neurosci 2022; 45:568-578. [PMID: 35659414 DOI: 10.1016/j.tins.2022.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/18/2022] [Accepted: 05/09/2022] [Indexed: 10/18/2022]
Abstract
Despite advances in understanding of corticospinal motor control and stroke pathophysiology, current rehabilitation therapies for poststroke upper limb paresis have limited efficacy at the level of impairment. To address this problem, we make the conceptual case for a new treatment approach. We first summarize current understanding of motor control deficits in the arm and hand after stroke and their shared physiological mechanisms with spinal cord injury (SCI). We then review studies of spinal cord stimulation (SCS) for recovery of locomotion after SCI, which provide convincing evidence for enhancement of residual corticospinal function. By extrapolation, we argue for using cervical SCS to restore upper limb motor control after stroke.
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Affiliation(s)
- Elvira Pirondini
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Erick Carranza
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Josep-Maria Balaguer
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Erynn Sorensen
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Douglas J Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA; Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, USA
| | - John W Krakauer
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA; The Santa Fe Institute, Santa Fe, CA, USA; Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
| | - Marco Capogrosso
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
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24
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Flett S, Garcia J, Cowley KC. Spinal electrical stimulation to improve sympathetic autonomic functions needed for movement and exercise after spinal cord injury: a scoping clinical review. J Neurophysiol 2022; 128:649-670. [PMID: 35894427 DOI: 10.1152/jn.00205.2022] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Spinal cord injury (SCI) results in sensory, motor and autonomic dysfunction. Obesity, cardiovascular and metabolic diseases are highly prevalent after SCI. Although inadequate voluntary activation of skeletal muscle contributes, it is absent or inadequate activation of thoracic spinal sympathetic neural circuitry and sub-optimal activation of homeostatic (cardiovascular, temperature) and metabolic support systems that truly limits exercise capacity, particularly for those with cervical SCI. Thus, when electrical spinal cord stimulation (SCS) studies aimed at improving motor functions began mentioning effects on exercise-related autonomic functions, a potential new area of clinical application appeared. To survey this new area of potential benefit, we performed a systematic scoping review of clinical SCS studies involving these spinally mediated autonomic functions. Nineteen studies were included, 8 used transcutaneous and 11 used epidural SCS. Improvements in BP at rest or in response to orthostatic challenge were investigated most systematically, whereas reports of improved temperature regulation, whole body metabolism and peak exercise performance were mainly anecdotal. Effective stimulation locations and parameters varied between studies, suggesting multiple stimulation parameters and rostrocaudal spinal locations may influence the same sympathetic function. Brainstem and spinal neural mechanisms providing excitatory drive to sympathetic neurons that activate homeostatic and metabolic tissues that provide support for movement and exercise and their integration with locomotor neural circuitry are discussed. A unifying conceptual framework for the integrated neural control of locomotor and sympathetic function is presented which may inform future research needed to take full advantage of SCS for improving these spinally mediated autonomic functions.
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Affiliation(s)
- Sarah Flett
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Juanita Garcia
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Kristine C Cowley
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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25
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Samejima S, Henderson R, Pradarelli J, Mondello SE, Moritz CT. Activity-dependent plasticity and spinal cord stimulation for motor recovery following spinal cord injury. Exp Neurol 2022; 357:114178. [PMID: 35878817 DOI: 10.1016/j.expneurol.2022.114178] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/22/2022] [Accepted: 07/16/2022] [Indexed: 02/07/2023]
Abstract
Spinal cord injuries lead to permanent physical impairment despite most often being anatomically incomplete disruptions of the spinal cord. Remaining connections between the brain and spinal cord create the potential for inducing neural plasticity to improve sensorimotor function, even many years after injury. This narrative review provides an overview of the current evidence for spontaneous motor recovery, activity-dependent plasticity, and interventions for restoring motor control to residual brain and spinal cord networks via spinal cord stimulation. In addition to open-loop spinal cord stimulation to promote long-term neuroplasticity, we also review a more targeted approach: closed-loop stimulation. Lastly, we review mechanisms of spinal cord neuromodulation to promote sensorimotor recovery, with the goal of advancing the field of rehabilitation for physical impairments following spinal cord injury.
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Affiliation(s)
- Soshi Samejima
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Richard Henderson
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA; Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Jared Pradarelli
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Sarah E Mondello
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Chet T Moritz
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA; Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA; Center for Neurotechnology, Seattle, WA, USA; Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
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26
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Dura JL, Solanes C, De Andres J, Saiz J. Effect of Lead Position and Polarity on Paresthesia Coverage in Spinal Cord Stimulation Therapy: A Computational Study. Neuromodulation 2022; 25:680-692. [DOI: 10.1016/j.neurom.2021.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/25/2021] [Accepted: 12/16/2021] [Indexed: 10/19/2022]
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27
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Shneider M, Pekker M. Theoretical model of external spinal cord stimulation. Phys Biol 2022; 19. [PMID: 35671753 DOI: 10.1088/1478-3975/ac768e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/07/2022] [Indexed: 11/11/2022]
Abstract
In this paper, a simple theoretical model of the excitation of action potentials of multiple motor pools by stimulating current pulses over the lumbosacral regions of the spinal cord is presented. The present model is consistent with known experimental data.
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Affiliation(s)
- Mikhail Shneider
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544-5263, USA, Princeton, New Jersey, 08544, UNITED STATES
| | - Mikhail Pekker
- Retired, 310 Elm Road,, Princeton, New Jersey, 08540, UNITED STATES
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28
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de Freitas RM, Capogrosso M, Nomura T, Milosevic M. Optimizing sensory fiber activation during cervical transcutaneous spinal stimulation using different electrode configurations: A computational analysis. Artif Organs 2022; 46:2015-2026. [PMID: 35642297 DOI: 10.1111/aor.14323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/21/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Cervical transcutaneous spinal cord stimulation (tSCS) is a rehabilitation tool which has been used to promote upper-limb motor recovery after spinal cord injury. Importantly, optimizing sensory fiber activation at specific spinal segments could enable activity-dependent neuromodulation during rehabilitation. METHODS An anatomically realistic cervical tSCS computational model was used to analyze the activation of α-motor and Aα-sensory fibers at C7 and C8 spinal segments using nine cathode electrode configurations. Specifically, the cathode was simulated at three vertebral level positions: C6, C7, and T1; and in three sizes: 5.0 x 5.0, 3.5 x 3.5; and 2.5 x 2.5 cm2 , while the anode was on the anterior neck. Finite element method was used to estimate the electric potential distribution along α-motor and Aα-sensory fibers, and computational models were applied to simulate the fiber membrane dynamics during tSCS. The minimum stimulation intensity necessary to activate the fibers (activation threshold) was estimated and compared across cathode configurations in an effort to optimize sensory fiber activation. RESULTS Our results showed that nerve fibers at both C7 and C8 spinal segments were recruited at lower stimulation intensities when the cathode was positioned over the C7 or T1 vertebra compared with the C6 position. Sensory fibers were activated at lower stimulation intensities using smaller electrodes, which could also affect the degree of nerve fiber activation across different positions. Importantly, Aα-sensory fibers were consistently recruited before α-motor fibers. CONCLUSIONS These results imply that cathode positioning could help optimize preferential activation of hand muscles during cervical tSCS.
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Affiliation(s)
- Roberto M de Freitas
- Graduate School of Engineering Science, Department of Mechanical Science and Bioengineering, Osaka University, Japan
| | - Marco Capogrosso
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, USA.,Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, USA.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA
| | - Taishin Nomura
- Graduate School of Engineering Science, Department of Mechanical Science and Bioengineering, Osaka University, Japan
| | - Matija Milosevic
- Graduate School of Engineering Science, Department of Mechanical Science and Bioengineering, Osaka University, Japan
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29
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de Freitas RM, Capogrosso M, Nomura T, Milosevic M. Preferential activation of proprioceptive and cutaneous sensory fibers compared to motor fibers during cervical transcutaneous spinal cord stimulation: A computational study. J Neural Eng 2022; 19. [PMID: 35472720 DOI: 10.1088/1741-2552/ac6a7c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/25/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Cervical transcutaneous spinal cord stimulation (tSCS) is a promising technology that can support motor function recovery of upper-limbs after spinal cord injury. Its efficacy may depend on the ability to recruit sensory afferents, conveying excitatory inputs onto motoneurons. Therefore, understanding its physiological mechanisms is critical to accelerate its development towards clinical applications. In this study, we used an anatomically realistic cervical tSCS computational model to compare α-motor, Aα-sensory, and Aβ-sensory fiber activation thresholds and activation sites. APPROACH We developed a 3D geometry of the cervical body and tSCS electrodes with a cathode centred at the C7 spinous process and an anode placed over the anterior neck. The geometrical model was used to estimate the electric potential distributions along motor and sensory fiber trajectories at the C7 spinal level using a finite element method. We implemented dedicated motor and sensory fiber models to simulate the α-motor and Aα-sensory fibers using 12, 16, and 20 µm diameter fibers, and Aβ-sensory fibers using 6, 9, and 12 µm diameter fibers. We estimated nerve fiber activation thresholds and sites for a 2 ms monophasic stimulating pulse and compared them across the fiber groups. MAIN RESULTS Our results showed lower activation thresholds of Aα- and Aβ-sensory fibers compared with α-motor fibers, suggesting preferential sensory fiber activation. We also found no differences between activation thresholds of Aα-sensory and large Aβ-sensory fibers, implying their co-activation. The activation sites were located at the dorsal and ventral root levels. SIGNIFICANCE Using a realistic computational model, we demonstrated preferential activation of dorsal root Aα- and Aβ-sensory fibers compared with ventral root α-motor fibers during cervical tSCS. These findings suggest high proprioceptive and cutaneous contributions to neural activations during cervical tSCS, which inform the underlying mechanisms of upper-limb functional motor recovery.
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Affiliation(s)
- Roberto M de Freitas
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, 560-8531, JAPAN
| | - Marco Capogrosso
- University of Pittsburgh, 3520, Fifth Av., Pittsburgh, Pennsylvania, 15261, UNITED STATES
| | - Taishin Nomura
- Department of Mechanical Science and Bioengineering, Osaka University, Machikaneyama 1-3, Toyonaka City, Osaka 560- 8531, Toyonaka, 5608531, JAPAN
| | - Matija Milosevic
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, J520, Toyonaka, Osaka, 560-8531, JAPAN
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30
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A simple model considering spiking probability during extracellular axon stimulation. PLoS One 2022; 17:e0264735. [PMID: 35446861 PMCID: PMC9022861 DOI: 10.1371/journal.pone.0264735] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022] Open
Abstract
The spiking probability of an electrically stimulated axon as a function of stimulus amplitude increases in a sigmoidal dependency from 0 to 1. However, most computer simulation studies for neuroprosthetic applications calculate thresholds for neural targets with a deterministic model and by reducing the sigmoid curve to a step function, they miss an important information about the control signal, namely how the spiking efficiency increases with stimulus intensity. Here, this spiking efficiency is taken into account in a compartment model of the Hodgkin Huxley type where a noise current is added in every compartment with an active membrane. A key parameter of the model is a common factor knoise which defines the ion current fluctuations across the cell membrane for every compartment by its maximum sodium ion conductance. In the standard model Gaussian signals are changed every 2.5 μs as a compromise of accuracy and computational costs. Additionally, a formula for other noise transmission times is presented and numerically tested. Spiking probability as a function of stimulus intensity can be approximated by the cumulative distribution function of the normal distribution with RS = σ/μ. Relative spread RS, introduced by Verveen, is a measure for the spread (normalized by the threshold intensity μ), that decreases inversely with axon diameter. Dynamic range, a related measure used in neuroprosthetic studies, defines the intensity range between 10% and 90% spiking probability. We show that (i) the dynamic range normalized by threshold is 2.56 times RS, (ii) RS increases with electrode—axon distance and (iii) we present knoise values for myelinated and unmyelinated axon models in agreement with recoded RS data. The presented method is applicable for other membrane models and can be extended to whole neurons that are described by multi-compartment models.
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31
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Atkinson DA, Steele AG, Manson GA, Sheynin J, Oh J, Gerasimenko YP, Sayenko DG. Characterization of interlimb interaction via transcutaneous spinal stimulation of cervical and lumbar spinal enlargements. J Neurophysiol 2022; 127:1075-1085. [PMID: 35320019 PMCID: PMC8993515 DOI: 10.1152/jn.00456.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 11/22/2022] Open
Abstract
The use of transcutaneous electrical spinal stimulation (TSS) to modulate sensorimotor networks after neurological insult has garnered much attention from both researchers and clinicians in recent years. Although many different stimulation paradigms have been reported, the interlimb effects of these neuromodulation techniques have been little studied. The effects of multisite TSS on interlimb sensorimotor function are of particular interest in the context of neurorehabilitation, as these networks have been shown to be important for functional recovery after neurological insult. The present study utilized a condition-test paradigm to investigate the effects of interenlargement TSS on spinal motor excitability in both cervical and lumbosacral motor pools. Additionally, comparison was made between the conditioning effects of lumbosacral and cervical TSS and peripheral stimulation of the fibular nerve and ulnar nerve, respectively. In 16/16 supine, relaxed participants, facilitation of spinally evoked motor responses (sEMRs) in arm muscles was seen in response to lumbosacral TSS or fibular nerve stimulation, whereas facilitation of sEMRs in leg muscles was seen in response to cervical TSS or ulnar nerve stimulation. The decreased latency between TSS- and peripheral nerve-evoked conditioning implicates interlimb networks in the observed facilitation of motor output. The results demonstrate the ability of multisite TSS to engage interlimb networks, resulting in the bidirectional influence of cervical and lumbosacral motor output. The engagement of interlimb networks via TSS of the cervical and lumbosacral enlargements represents a feasible method for engaging spinal sensorimotor networks in clinical populations with compromised motor function.NEW & NOTEWORTHY Bidirectional interlimb modulation of spinal motor excitability can be evoked by transcutaneous spinal stimulation over the cervical and lumbosacral enlargements. Multisite transcutaneous spinal stimulation engages spinal sensorimotor networks thought to be important in the recovery of function after spinal cord injury.
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Affiliation(s)
- D. A. Atkinson
- Doctor of Physical Therapy program, University of St. Augustine for Health Sciences, Austin, Texas
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
| | - A. G. Steele
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas
| | - G. A. Manson
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
- School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario, Canada
| | - J. Sheynin
- Department of Psychiatry and Behavioral Science, Texas A&M University Health Science Center, Houston, Texas
| | - J. Oh
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
| | - Y. P. Gerasimenko
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
- Department of Physiology, University of Louisville, Louisville, Kentucky
- Pavlov Institute of Physiology, St. Petersburg, Russia
| | - D. G. Sayenko
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
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Fellner A, Heshmat A, Werginz P, Rattay F. A finite element method framework to model extracellular neural stimulation. J Neural Eng 2022; 19. [PMID: 35320783 DOI: 10.1088/1741-2552/ac6060] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/23/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Increasing complexity in extracellular stimulation experiments and neural implant design also requires realistic computer simulations capable of modeling the neural activity of nerve cells under the influence of an electrical stimulus. Classical model approaches are often based on simplifications, are not able to correctly calculate the electric field generated by complex electrode designs, and do not consider electrical effects of the cell on its surrounding. A more accurate approach is the finite element method (FEM), which provides necessary techniques to solve the Poisson equation for complex geometries under consideration of electrical tissue properties. Especially in situations where neurons experience large and non-symmetric extracellular potential gradients, a FEM solution that implements the cell membrane model can improve the computer simulation results. To investigate the response of neurons in an electric field generated by complex electrode designs, a FEM framework for extracellular stimulation was developed in COMSOL. APPROACH Methods to implement morphologically- and biophysically-detailed neurons including active Hodgkin-Huxley (HH) cell membrane dynamics as well as the stimulation setup are described in detail. Covered methods are (i) development of cell and electrode geometries including meshing strategies, (ii) assignment of physics for the conducting spaces and the realization of active electrodes, (iii) implementation of the HH model, and (iv) coupling of the physics to get a fully described model. MAIN RESULTS Several implementation examples are briefly presented: (i) a full FEM implementation of a HH model cell stimulated with a honeycomb electrode, (ii) the electric field of a cochlear electrode placed inside the cochlea, and (iii) a proof of concept implementation of a detailed double-cable cell membrane model for myelinated nerve fibers. SIGNIFICANCE The presented concepts and methods provide basic and advanced techniques to realize a full FEM framework for innovative studies of neural excitation in response to extracellular stimulation.
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Affiliation(s)
- Andreas Fellner
- Institute of Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstraße 8-10, Vienna, Vienna, 1040, AUSTRIA
| | - Amirreza Heshmat
- Department of Otorhinolaryngology, Innsbruck Medical University, Anichstrasse 35, Innsbruck, 6020, AUSTRIA
| | - Paul Werginz
- Institute of Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstraße 8-10, Vienna, Vienna, 1040, AUSTRIA
| | - Frank Rattay
- Institute of Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstraße 8-10, Vienna, Vienna, 1040, AUSTRIA
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Effects of paired stimulation with specific waveforms on cortical and spinal plasticity in subjects with a chronic spinal cord injury. J Formos Med Assoc 2022; 121:2044-2056. [DOI: 10.1016/j.jfma.2022.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 12/13/2021] [Accepted: 02/17/2022] [Indexed: 12/16/2022] Open
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Laskin JJ, Waheed Z, Thorogood NP, Nightingale TE, Noonan VK. Spinal cord stimulation research in the restoration of motor, sensory and autonomic function for individuals living with spinal cord injuries: A scoping review. Arch Phys Med Rehabil 2022; 103:1387-1397. [PMID: 35202581 DOI: 10.1016/j.apmr.2022.01.161] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To describe the status of spinal cord stimulation (SCS) research for the improvement of motor, sensory and autonomic function for individuals living with a spinal cord injury (SCI). DATA SOURCES This scoping review identified original research published prior to March 31, 2021, via literature searches using Medline, EMBASE, PubMed, Science Direct, CINAHL, Sport Discus, Web of Science, as well as a targeted search for well-known principal investigators. Search terms included permutations of "spinal cord stimulation", "epidural spinal cord stimulation", "transcutaneous spinal cord stimulation", "magnetic spinal cord stimulation" and "neuromodulation". STUDY SELECTION Studies were included if they: 1) were in English, 2) presented original research on humans living with a SCI, and 3) investigated at least one of the three forms of SCS. DATA EXTRACTION Extracted data included: authors, publication year, participant characteristics, purpose, study design, stimulation (device, location, parameters,) primary outcomes, and adverse events. DATA SYNTHESIS As a scoping review the extracted data was tabulated and presented descriptively. Themes and gaps in the literature were identified and reported. Of the 5,754 articles screened, 103 articles were included (55 epidural, 36 transcutaneous and 12 magnetic). The primary research design was a case study or series with only a single randomized clinical trial. Motor recovery was the most common primary outcome for epidural and transcutaneous SCS studies whereas bowel and bladder outcomes were most common for magnetic. Seventy percent of the studies included 10 or fewer participants, and 18 articles documented at least one adverse event. Incomplete stimulation parameter descriptions were noted across many studies. No articles mentioned direct engagement of consumers or advocacy groups. CONCLUSION This review identified a need for more robust study designs, larger sample sizes, comparative studies, improved reporting of stimulation parameters, adverse event data, and alignment of outcomes with the priorities of the SCI community.
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Affiliation(s)
- James J Laskin
- Praxis Spinal Cord Institute, Vancouver, British Columbia, Canada; School of Physical Therapy and Rehabilitation Science, University of Montana, Missoula, Montana.
| | - Zeina Waheed
- Praxis Spinal Cord Institute, Vancouver, British Columbia, Canada
| | | | - Tom E Nightingale
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom; Centre for Trauma Sciences Research, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Vanessa K Noonan
- Praxis Spinal Cord Institute, Vancouver, British Columbia, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
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Grau-Ruiz D, Rigla JP, Pallás E, Algarín JM, Borreguero J, Bosch R, López-Comazzi G, Galve F, Díaz-Caballero E, Gramage C, González JM, Pellicer R, Ríos A, Benlloch JM, Alonso J. Magneto-stimulation limits in medical imaging applications with rapid field dynamics. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac515c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/02/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The goal of this work is to extend previous peripheral nerve stimulation (PNS) studies to scenarios relevant to magnetic particle imaging (MPI) and low-field magnetic resonance imaging (MRI), where field dynamics can evolve at kilo-hertz frequencies. Approach. We have constructed an apparatus for PNS threshold determination on a subject’s limb, capable of narrow and broad-band magnetic stimulation with pulse characteristic times down to 40 μs. Main result. From a first set of measurements on 51 volunteers, we conclude that the PNS dependence on pulse frequency/rise-time is compatible with traditional stimulation models where nervous responses are characterized by a rheobase and a chronaxie. Additionally, we have extended pulse length studies to these fast timescales and confirm thresholds increase significantly as trains transition from tens to a few pulses. We also look at the influence of field spatial distribution on PNS effects, and find that thresholds are higher in an approximately linearly inhomogeneous field (relevant to MRI) than in a rather homogeneous distribution (as in MPI). Significance. PNS constrains the clinical performance of MRI and MPI systems. Extensive magneto-stimulation studies have been carried out recently in the field of MPI, where typical operation frequencies range from single to tens of kilo-hertz. However, PNS literature is scarce for MRI in this fast regime, relevant to small (low inductance) dedicated MRI setups, and where the resonant character of MPI coils prevents studies of broad-band stimulation pulses. This work advances in this direction.
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Barss TS, Parhizi B, Porter J, Mushahwar VK. Neural Substrates of Transcutaneous Spinal Cord Stimulation: Neuromodulation across Multiple Segments of the Spinal Cord. J Clin Med 2022; 11:639. [PMID: 35160091 PMCID: PMC8836636 DOI: 10.3390/jcm11030639] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
Transcutaneous spinal cord stimulation (tSCS) has the potential to promote improved sensorimotor rehabilitation by modulating the circuitry of the spinal cord non-invasively. Little is currently known about how cervical or lumbar tSCS influences the excitability of spinal and corticospinal networks, or whether the synergistic effects of multi-segmental tSCS occur between remote segments of the spinal cord. The aim of this review is to describe the emergence and development of tSCS as a novel method to modulate the spinal cord, while highlighting the effectiveness of tSCS in improving sensorimotor recovery after spinal cord injury. This review underscores the ability of single-site tSCS to alter excitability across multiple segments of the spinal cord, while multiple sites of tSCS converge to facilitate spinal reflex and corticospinal networks. Finally, the potential and current limitations for engaging cervical and lumbar spinal cord networks through tSCS to enhance the effectiveness of rehabilitation interventions are discussed. Further mechanistic work is needed in order to optimize targeted rehabilitation strategies and improve clinical outcomes.
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Affiliation(s)
- Trevor S. Barss
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada; (T.S.B.); (B.P.)
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Behdad Parhizi
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada; (T.S.B.); (B.P.)
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Jane Porter
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Vivian K. Mushahwar
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada; (T.S.B.); (B.P.)
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB T6G 2R3, Canada
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Davids M, Guerin B, Wald LL. A Huygens' surface approach to rapid characterization of peripheral nerve stimulation. Magn Reson Med 2022; 87:377-393. [PMID: 34427346 PMCID: PMC8689355 DOI: 10.1002/mrm.28966] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/18/2021] [Accepted: 07/22/2021] [Indexed: 11/06/2022]
Abstract
PURPOSE Peripheral nerve stimulation (PNS) modeling has a potential role in designing and operating MRI gradient coils but requires computationally demanding simulations of electromagnetic fields and neural responses. We demonstrate compression of an electromagnetic and neurodynamic model into a single versatile PNS matrix (P-matrix) defined on an intermediary Huygens' surface to allow fast PNS characterization of arbitrary coil geometries and body positions. METHODS The Huygens' surface approach divides PNS prediction into an extensive pre-computation phase of the electromagnetic and neurodynamic responses, which is independent of coil geometry and patient position, and a fast coil-specific linear projection step connecting this information to a specific coil geometry. We validate the Huygens' approach by performing PNS characterizations for 21 body and head gradients and comparing them with full electromagnetic-neurodynamic modeling. We demonstrate the value of Huygens' surface-based PNS modeling by characterizing PNS-optimized coil windings for a wide range of patient positions and poses in two body models. RESULTS The PNS prediction using the Huygens' P-matrix takes less than a minute (instead of hours to days) without compromising numerical accuracy (error ≤ 0.1%) compared to the full simulation. Using this tool, we demonstrate that coils optimized for PNS at the brain landmark using a male model can also improve PNS for other imaging applications (cardiac, abdominal, pelvic, and knee imaging) in both male and female models. CONCLUSION Representing PNS information on a Huygens' surface extended the approach's ability to assess PNS across body positions and models and test the robustness of PNS optimization in gradient design.
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Affiliation(s)
- Mathias Davids
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Bastien Guerin
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Lawrence L. Wald
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
- Harvard-MIT Division of Health Sciences Technology, Cambridge, Massachusetts, USA
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Steele AG, Atkinson DA, Varghese B, Oh J, Markley RL, Sayenko DG. Characterization of Spinal Sensorimotor Network Using Transcutaneous Spinal Stimulation during Voluntary Movement Preparation and Performance. J Clin Med 2021; 10:jcm10245958. [PMID: 34945253 PMCID: PMC8709482 DOI: 10.3390/jcm10245958] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 12/12/2022] Open
Abstract
Transcutaneous electrical spinal stimulation (TSS) can be used to selectively activate motor pools based on their anatomical arrangements in the lumbosacral enlargement. These spatial patterns of spinal motor activation may have important clinical implications, especially when there is a need to target specific muscle groups. However, our understanding of the net effects and interplay between the motor pools projecting to agonist and antagonist muscles during the preparation and performance of voluntary movements is still limited. The present study was designed to systematically investigate and differentiate the multi-segmental convergence of supraspinal inputs on the lumbosacral neural network before and during the execution of voluntary leg movements in neurologically intact participants. During the experiments, participants (N = 13) performed isometric (1) knee flexion and (2) extension, as well as (3) plantarflexion and (4) dorsiflexion. TSS consisting of a pair pulse with 50 ms interstimulus interval was delivered over the T12-L1 vertebrae during the muscle contractions, as well as within 50 to 250 ms following the auditory or tactile stimuli, to characterize the temporal profiles of net spinal motor output during movement preparation. Facilitation of evoked motor potentials in the ipsilateral agonists and contralateral antagonists emerged as early as 50 ms following the cue and increased prior to movement onset. These results suggest that the descending drive modulates the activity of the inter-neuronal circuitry within spinal sensorimotor networks in specific, functionally relevant spatiotemporal patterns, which has a direct implication for the characterization of the state of those networks in individuals with neurological conditions.
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Affiliation(s)
- Alexander G. Steele
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
- Department of Electrical and Computer Engineering, University of Houston, E413 Engineering Bldg 2, 4726 Calhoun Road, Houston, TX 77204, USA
| | - Darryn A. Atkinson
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
- College of Rehabilitative Sciences, University of St. Augustine for Health Sciences, 5401 La Crosse Avenue, Austin, TX 78739, USA
| | - Blesson Varghese
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
| | - Jeonghoon Oh
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
| | - Rachel L. Markley
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
| | - Dimitry G. Sayenko
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, 6550 Fannin Street, Houston, TX 77030, USA; (A.G.S.); (D.A.A.); (B.V.); (J.O.); (R.L.M.)
- Correspondence: ; Tel.: +1-713-363-9910
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Alashram AR, Padua E, Raju M, Romagnoli C, Annino G. Transcutaneous spinal cord stimulation effects on spasticity in patients with spinal cord injury: A systematic review. J Spinal Cord Med 2021:1-8. [PMID: 34855565 DOI: 10.1080/10790268.2021.2000200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CONTEXT Spasticity is one of the most prevalent impairments following spinal cord injury (SCI). It can lead to a decrease in the patient's functional level. Transcutaneous spinal cord stimulation (tSCS) has demonstrated motor function improvements following SCI. No systematic reviews were published examining the influences of tSCS on spasticity post-SCI. OBJECTIVES This review aimed to investigate the effects of tSCS on spasticity in patients with SCI. METHODS PubMed, SCOPUS, PEDro, CINAHL, MEDLINE, REHABDATA, AMED, and Web of Science databases were searched until June 2021. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the selected studies. RESULTS Six studies met the inclusion criteria. Five studies were pilot studies, and one was a case series. The scores on the PEDro scale ranged from two to four, with a median score of four. The results showed heterogenous evidence for the effects of tSCS on spasticity reduction post-SCI. CONCLUSIONS TSCS appears safe and well-tolerated intervention in patients with SCI. The evidence for the effectiveness of tSCS on spasticity in chronic SCI patients is limited. Further randomized controlled studies are strongly needed to study the effects of tSCS on patients with SCI.
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Affiliation(s)
| | - Elvira Padua
- Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, Rome, Italy
| | - Manikandan Raju
- Clinical/Experimental Neuroscience and Psychology, Department of Neuroscience Umane, University of Sapienza, Rome, Italy
| | - Cristian Romagnoli
- PhD School in Science and Culture of Well-being and Lifestyle, Alma Mater University, Bologna, Italy
| | - Giuseppe Annino
- Department of Medicine Systems, University of Rome "Tor Vergata", Rome, Italy
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Hachmann JT, Yousak A, Wallner JJ, Gad PN, Edgerton VR, Gorgey AS. Epidural spinal cord stimulation as an intervention for motor recovery after motor complete spinal cord injury. J Neurophysiol 2021; 126:1843-1859. [PMID: 34669485 DOI: 10.1152/jn.00020.2021] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 10/12/2021] [Indexed: 12/19/2022] Open
Abstract
Spinal cord injury (SCI) commonly results in permanent loss of motor, sensory, and autonomic function. Recent clinical studies have shown that epidural spinal cord stimulation may provide a beneficial adjunct for restoring lower extremity and other neurological functions. Herein, we review the recent clinical advances of lumbosacral epidural stimulation for restoration of sensorimotor function in individuals with motor complete SCI and we discuss the putative neural pathways involved in this promising neurorehabilitative approach. We focus on three main sections: review recent clinical results for locomotor restoration in complete SCI; discuss the contemporary understanding of electrical neuromodulation and signal transduction pathways involved in spinal locomotor networks; and review current challenges of motor system modulation and future directions toward integrative neurorestoration. The current understanding is that initial depolarization occurs at the level of large diameter dorsal root proprioceptive afferents that when integrated with interneuronal and latent residual supraspinal translesional connections can recruit locomotor centers and augment downstream motor units. Spinal epidural stimulation can initiate excitability changes in spinal networks and supraspinal networks. Different stimulation parameters can facilitate standing or stepping, and it may also have potential for augmenting myriad other sensorimotor and autonomic functions. More comprehensive investigation of the mechanisms that mediate the transformation of dysfunctional spinal networks to higher functional states with a greater focus on integrated systems-based control system may reveal the key mechanisms underlying neurological augmentation and motor restoration after severe paralysis.
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Affiliation(s)
- Jan T Hachmann
- Department of Neurological Surgery, Virginia Commonwealth University, Richmond, Virginia
| | - Andrew Yousak
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
| | - Josephine J Wallner
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
| | - Parag N Gad
- Department of Neurobiology, University of California, Los Angeles, California
| | - V Reggie Edgerton
- Department of Neurobiology, University of California, Los Angeles, California
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Badalona, Barcelona, Spain
| | - Ashraf S Gorgey
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
- Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, Virginia
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Influence of Spine Curvature on the Efficacy of Transcutaneous Lumbar Spinal Cord Stimulation. J Clin Med 2021; 10:jcm10235543. [PMID: 34884249 PMCID: PMC8658162 DOI: 10.3390/jcm10235543] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/15/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022] Open
Abstract
Transcutaneous spinal cord stimulation is a non-invasive method for neuromodulation of sensorimotor function. Its main mechanism of action results from the activation of afferent fibers in the posterior roots-the same structures as targeted by epidural stimulation. Here, we investigated the influence of sagittal spine alignment on the capacity of the surface-electrode-based stimulation to activate these neural structures. We evaluated electromyographic responses evoked in the lower limbs of ten healthy individuals during extension, flexion, and neutral alignment of the thoracolumbar spine. To control for position-specific effects, stimulation in these spine alignment conditions was performed in four different body positions. In comparison to neutral and extended spine alignment, flexion of the spine resulted in a strong reduction of the response amplitudes. There was no such effect on tibial-nerve evoked H reflexes. Further, there was a reduction of post-activation depression of the responses to transcutaneous spinal cord stimulation evoked in spinal flexion. Thus, afferent fibers were reliably activated with neutral and extended spine alignment. Spinal flexion, however, reduced the capacity of the stimulation to activate afferent fibers and led to the co-activation of motor fibers in the anterior roots. This change of action was due to biophysical rather than neurophysiological influences. We recommend applying transcutaneous spinal cord stimulation in body positions that allow individuals to maintain a neutral or extended spine.
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Salchow-Hömmen C, Schauer T, Müller P, Kühn AA, Hofstoetter US, Wenger N. Algorithms for Automated Calibration of Transcutaneous Spinal Cord Stimulation to Facilitate Clinical Applications. J Clin Med 2021; 10:jcm10225464. [PMID: 34830746 PMCID: PMC8623351 DOI: 10.3390/jcm10225464] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/06/2021] [Accepted: 11/13/2021] [Indexed: 12/15/2022] Open
Abstract
Transcutaneous spinal cord stimulation (tSCS) is a promising intervention that can benefit spasticity control and augment voluntary movement in spinal cord injury (SCI) and multiple sclerosis. Current applications require expert knowledge and rely on the thorough visual analysis of electromyographic (EMG) responses from lower-limb muscles to optimize attainable treatment effects. Here, we devised an automated tSCS setup by combining an electrode array placed over low-thoracic to mid-lumbar vertebrae, synchronized EMG recordings, and a self-operating stimulation protocol to systematically test various stimulation sites and amplitudes. A built-in calibration procedure classifies the evoked responses as reflexes or direct motor responses and identifies stimulation thresholds as recommendations for tSCS therapy. We tested our setup in 15 individuals (five neurologically intact, five SCI, and five Parkinson’s disease) and validated the results against blinded ratings from two clinical experts. Congruent results were obtained in 13 cases for electrode positions and in eight for tSCS amplitudes, with deviations of a maximum of one position and 5 to 10 mA in amplitude in the remaining cases. Despite these minor deviations, the calibration found clinically suitable tSCS settings in 13 individuals. In the remaining two cases, the automatic setup and both experts agreed that no reflex responses could be detected. The presented technological developments may facilitate the dissemination of tSCS into non-academic environments and broaden its use for diagnostic and therapeutic purposes.
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Affiliation(s)
- Christina Salchow-Hömmen
- Department of Neurology, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany; (C.S.-H.); (A.A.K.); (N.W.)
| | - Thomas Schauer
- Control Systems Group, Technische Universität Berlin, 10587 Berlin, Germany;
- Correspondence: ; Tel.: +49-(0)30-314-24404
| | - Philipp Müller
- Control Systems Group, Technische Universität Berlin, 10587 Berlin, Germany;
| | - Andrea A. Kühn
- Department of Neurology, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany; (C.S.-H.); (A.A.K.); (N.W.)
| | - Ursula S. Hofstoetter
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria;
| | - Nikolaus Wenger
- Department of Neurology, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany; (C.S.-H.); (A.A.K.); (N.W.)
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Taylor C, McHugh C, Mockler D, Minogue C, Reilly RB, Fleming N. Transcutaneous spinal cord stimulation and motor responses in individuals with spinal cord injury: A methodological review. PLoS One 2021; 16:e0260166. [PMID: 34793572 PMCID: PMC8601579 DOI: 10.1371/journal.pone.0260166] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/03/2021] [Indexed: 11/18/2022] Open
Abstract
Background Transcutaneous spinal cord stimulation (tSCS) is a non-invasive modality in which electrodes can stimulate spinal circuitries and facilitate a motor response. This review aimed to evaluate the methodology of studies using tSCS to generate motor activity in persons with spinal cord injury (SCI) and to appraise the quality of included trials. Methods A systematic search for studies published until May 2021 was made of the following databases: EMBASE, Medline (Ovid) and Web of Science. Two reviewers independently screened the studies, extracted the data, and evaluated the quality of included trials. The electrical characteristics of stimulation were summarised to allow for comparison across studies. In addition, the surface electromyography (EMG) recording methods were evaluated. Results A total of 3753 articles were initially screened, of which 25 met the criteria for inclusion. Studies were divided into those using tSCS for neurophysiological investigations of reflex responses (n = 9) and therapeutic investigations of motor recovery (n = 16). The overall quality of evidence was deemed to be poor-to-fair (10.5 ± 4.9) based on the Downs and Black Quality Checklist criteria. The electrical characteristics were collated to establish the dosage range across stimulation trials. The methods employed by included studies relating to stimulation parameters and outcome measurement varied extensively, although some trends are beginning to appear in relation to electrode configuration and EMG outcomes. Conclusion This review outlines the parameters currently employed for tSCS of the cervicothoracic and thoracolumbar regions to produce motor responses. However, to establish standardised procedures for neurophysiological assessments and therapeutic investigations of tSCS, further high-quality investigations are required, ideally utilizing consistent electrophysiological recording methods, and reporting common characteristics of the electrical stimulation administered.
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Affiliation(s)
- Clare Taylor
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
- * E-mail:
| | - Conor McHugh
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - David Mockler
- John Stearne Medical Library, Trinity Centre for Health Sciences, School of Medicine, St. James’s Hospital, Dublin, Ireland
| | - Conor Minogue
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - Richard B. Reilly
- Trinity Centre for Biomedical Engineering, Trinity College, The University of Dublin, Dublin, Ireland
- School of Engineering, Trinity College, The University of Dublin, Dublin, Ireland
- School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - Neil Fleming
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
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Kaneko N, Sasaki A, Masugi Y, Nakazawa K. The Effects of Paired Associative Stimulation with Transcutaneous Spinal Cord Stimulation on Corticospinal Excitability in Multiple Lower-limb Muscles. Neuroscience 2021; 476:45-59. [PMID: 34500017 DOI: 10.1016/j.neuroscience.2021.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022]
Abstract
Paired associative stimulation (PAS) is a non-invasive method to modulate the excitability of the primary motor cortex (M1). PAS involves the combination of peripheral nerve stimulation and transcranial magnetic stimulation (TMS) over the primary motor cortex. However, for lower-limb muscles, PAS has only been applied to the few muscles innervated by peripheral nerves that can easily be stimulated. This study used transcutaneous spinal cord stimulation (tSCS) to the posterior root, stimulating the sensory nerves of multiple lower-limb muscles, and aimed to investigate the effect of PAS consisting of tSCS and TMS on corticospinal excitability. Twelve non-disabled men received 120 paired stimuli on two separate days in (1) an individual-ISI condition, using inter-stimulus intervals (ISIs) of paired stimuli individually calculated to send two signals to M1 with individually-adjusted ISI, and (2) a constant-ISI condition, using a constant ISI of 100 ms. Before and after PAS, corticospinal excitability was assessed in the lower-limb muscles. Facilitation of corticospinal excitability in the lower-leg and hamstring muscles was observed up to 30 min after PAS only in the individual-ISI condition (p < 0.05), although there was no significant difference between the individual-ISI and constant-ISI conditions. Additionally, our results revealed a difference in PAS-induced facilitation among lower-limb muscles, suggesting a spatial gradient of PAS-induced facilitation of corticospinal excitability, such that knee flexor muscles have a higher potential for plastic change than knee extensor muscles. These findings will foster a better understanding of the neural mechanisms underlying PAS-induced neuroplasticity, leading to better neurorehabilitation and motor learning strategies.
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Affiliation(s)
- Naotsugu Kaneko
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; Japan Society for the Promotion of Science, Tokyo, Japan; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; KITE, Toronto Rehabilitation Institute - University Health Network, Toronto, ON, Canada
| | - Atsushi Sasaki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yohei Masugi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; School of Health Sciences, Tokyo International University, Saitama, Japan
| | - Kimitaka Nakazawa
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
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Seáñez I, Capogrosso M. Motor improvements enabled by spinal cord stimulation combined with physical training after spinal cord injury: review of experimental evidence in animals and humans. Bioelectron Med 2021; 7:16. [PMID: 34706778 PMCID: PMC8555080 DOI: 10.1186/s42234-021-00077-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/30/2021] [Indexed: 12/20/2022] Open
Abstract
Electrical spinal cord stimulation (SCS) has been gaining momentum as a potential therapy for motor paralysis in consequence of spinal cord injury (SCI). Specifically, recent studies combining SCS with activity-based training have reported unprecedented improvements in motor function in people with chronic SCI that persist even without stimulation. In this work, we first provide an overview of the critical scientific advancements that have led to the current uses of SCS in neurorehabilitation: e.g. the understanding that SCS activates dormant spinal circuits below the lesion by recruiting large-to-medium diameter sensory afferents within the posterior roots. We discuss how this led to the standardization of implant position which resulted in consistent observations by independent clinical studies that SCS in combination with physical training promotes improvements in motor performance and neurorecovery. While all reported participants were able to move previously paralyzed limbs from day 1, recovery of more complex motor functions was gradual, and the timeframe for first observations was proportional to the task complexity. Interestingly, individuals with SCI classified as AIS B and C regained motor function in paralyzed joints even without stimulation, but not individuals with motor and sensory complete SCI (AIS A). Experiments in animal models of SCI investigating the potential mechanisms underpinning this neurorecovery suggest a synaptic reorganization of cortico-reticulo-spinal circuits that correlate with improvements in voluntary motor control. Future experiments in humans and animal models of paralysis will be critical to understand the potential and limits for functional improvements in people with different types, levels, timeframes, and severities of SCI.
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Affiliation(s)
- Ismael Seáñez
- Biomedical Engineering, Washington University in St. Louis, St. Louis, USA. .,Neurosurgery, Washington University School of Medicine in St. Louis, St. Louis, USA.
| | - Marco Capogrosso
- Neurological Surgery, University of Pittsburgh, Pittsburgh, USA.,Department of Physical Medicine and Rehabilitation, Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, USA.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA
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Calvert JS, Gill ML, Linde MB, Veith DD, Thoreson AR, Lopez C, Lee KH, Gerasimenko YP, Edgerton VR, Lavrov IA, Zhao KD, Grahn PJ, Sayenko DG. Voluntary Modulation of Evoked Responses Generated by Epidural and Transcutaneous Spinal Stimulation in Humans with Spinal Cord Injury. J Clin Med 2021; 10:jcm10214898. [PMID: 34768418 PMCID: PMC8584516 DOI: 10.3390/jcm10214898] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 12/29/2022] Open
Abstract
Transcutaneous (TSS) and epidural spinal stimulation (ESS) are electrophysiological techniques that have been used to investigate the interactions between exogenous electrical stimuli and spinal sensorimotor networks that integrate descending motor signals with afferent inputs from the periphery during motor tasks such as standing and stepping. Recently, pilot-phase clinical trials using ESS and TSS have demonstrated restoration of motor functions that were previously lost due to spinal cord injury (SCI). However, the spinal network interactions that occur in response to TSS or ESS pulses with spared descending connections across the site of SCI have yet to be characterized. Therefore, we examined the effects of delivering TSS or ESS pulses to the lumbosacral spinal cord in nine individuals with chronic SCI. During low-frequency stimulation, participants were instructed to relax or attempt maximum voluntary contraction to perform full leg flexion while supine. We observed similar lower-extremity neuromusculature activation during TSS and ESS when performed in the same participants while instructed to relax. Interestingly, when participants were instructed to attempt lower-extremity muscle contractions, both TSS- and ESS-evoked motor responses were significantly inhibited across all muscles. Participants with clinically complete SCI tested with ESS and participants with clinically incomplete SCI tested with TSS demonstrated greater ability to modulate evoked responses than participants with motor complete SCI tested with TSS, although this was not statistically significant due to a low number of subjects in each subgroup. These results suggest that descending commands combined with spinal stimulation may increase activity of inhibitory interneuronal circuitry within spinal sensorimotor networks in individuals with SCI, which may be relevant in the context of regaining functional motor outcomes.
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Affiliation(s)
- Jonathan S. Calvert
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, USA;
| | - Megan L. Gill
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
| | - Margaux B. Linde
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
| | - Daniel D. Veith
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
| | - Andrew R. Thoreson
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
| | - Cesar Lopez
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
| | - Kendall H. Lee
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA;
- Department of Physiology and Biomedical Engineering, Rochester, MN 55905, USA
| | - Yury P. Gerasimenko
- Pavlov Institute of Physiology of Russian Academy of Sciences, 199034 St. Petersburg, Russia;
- Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40292, USA
| | - Victor R. Edgerton
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA;
- Department of Neurobiology, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA 90095, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
- Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo 2007, Australia
| | - Igor A. Lavrov
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA;
| | - Kristin D. Zhao
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
- Department of Physiology and Biomedical Engineering, Rochester, MN 55905, USA
| | - Peter J. Grahn
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; (M.L.G.); (M.B.L.); (D.D.V.); (A.R.T.); (C.L.); (K.H.L.); (K.D.Z.); (P.J.G.)
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA;
| | - Dimitry G. Sayenko
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-363-7949
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Martins Â, Gouveia D, Cardoso A, Carvalho C, Coelho T, Silva C, Viegas I, Gamboa Ó, Ferreira A. A Controlled Clinical Study of Intensive Neurorehabilitation in Post-Surgical Dogs with Severe Acute Intervertebral Disc Extrusion. Animals (Basel) 2021; 11:ani11113034. [PMID: 34827767 PMCID: PMC8614363 DOI: 10.3390/ani11113034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/16/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Simple Summary This study explores the potential intensive neurorehabilitation plasticity effects in post-surgical paraplegic dogs with severe acute intervertebral disc extrusion aiming to achieve ambulatory status. The intensive neurorehabilitation protocol translated in 99.4% (167/168) of recovery in deep pain perception-positive dogs and 58.5% (55/94) in deep pain perception-negative dogs. There was 37.3% (22/59) spinal reflex locomotion, obtained within a maximum period of 3 months. Thus, intensive neurorehabilitation may be a useful approach for this population of dogs, avoiding future euthanasia and promoting an estimated time window of 3 months to recover. Abstract This retrospective controlled clinical study aimed to verify if intensive neurorehabilitation (INR) could improve ambulation faster than spontaneous recovery or conventional physiotherapy and provide a possible therapeutic approach in post-surgical paraplegic deep pain perception-positive (DPP+) (with absent/decreased flexor reflex) and DPP-negative (DDP−) dogs, with acute intervertebral disc extrusion. A large cohort of T10-L3 Spinal Cord Injury (SCI) dogs (n = 367) were divided into a study group (SG) (n = 262) and a control group (CG) (n = 105). The SG was based on prospective clinical cases, and the CG was created by retrospective medical records. All SG dogs performed an INR protocol by the hospitalization regime based on locomotor training, electrical stimulation, and, for DPP−, a combination with pharmacological management. All were monitored throughout the process, and measuring the outcome for DPP+ was performed by OFS and, for the DPP−, by the new Functional Neurorehabilitation Scale (FNRS-DPP−). In the SG, DPP+ dogs had an ambulation rate of 99.4% (n = 167) and, in DPP−, of 58.5% (n = 55). Moreover, in DPP+, there was a strong statistically significant difference between groups regarding ambulation (p < 0.001). The same significant difference was verified in the DPP– dogs (p = 0.007). Furthermore, a tendency toward a significant statistical difference (p = 0.058) regarding DPP recovery was demonstrated between groups. Of the 59 dogs that did not recover DPP, 22 dogs achieved spinal reflex locomotion (SRL), 37.2% within a maximum of 3 months. The progressive myelomalacia cases were 14.9% (14/94). Therefore, although it is difficult to assess the contribution of INR for recovery, the results suggested that ambulation success may be improved, mainly regarding time.
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Affiliation(s)
- Ângela Martins
- Faculty of Veterinary Medicine, Lusófona University, Campo Grande, 1300-477 Lisboa, Portugal
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
- Correspondence:
| | - Débora Gouveia
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
| | - Ana Cardoso
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
| | - Carla Carvalho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
| | - Tiago Coelho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
| | - Cátia Silva
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
| | - Inês Viegas
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (T.C.); (C.S.); (I.V.)
| | - Óscar Gamboa
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
| | - António Ferreira
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
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Therkildsen ER, Nielsen JB, Beck MM, Yamaguchi T, Lorentzen J. The effect of cathodal transspinal direct current stimulation on tibialis anterior stretch reflex components in humans. Exp Brain Res 2021; 240:159-171. [PMID: 34686909 DOI: 10.1007/s00221-021-06243-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 10/08/2021] [Indexed: 01/04/2023]
Abstract
Spinal DC stimulation (tsDCS) shows promise as a technique for the facilitation of functional recovery of motor function following central nervous system (CNS) lesion. However, the network mechanisms that are responsible for the effects of tsDCS are still uncertain. Here, in a series of experiments, we tested the hypothesis that tsDCS increases the excitability of the long-latency stretch reflex, leading to increased excitability of corticospinal neurons in the primary motor cortex. Experiments were performed in 33 adult human subjects (mean age 28 ± 7 years/14 females). Subjects were seated in a reclining armchair with the right leg attached to a footplate, which could be quickly plantarflexed (100 deg/s; 6 deg amplitude) to induce stretch reflexes in the tibialis anterior (TA) muscle at short (45 ms) and longer latencies (90-95 ms). This setup also enabled measuring motor evoked potentials (MEPs) and cervicomedullary evoked potentials (cMEPs) from TA evoked by transcranial magnetic stimulation (TMS) and electrical stimulation at the cervical junction, respectively. Cathodal tsDCS at 2.5 and 4 mA was found to increase the long-latency reflex without any significant effect on the short-latency reflex. Furthermore, TA MEPs, but not cMEPs, were increased following tsDCS. We conclude that cathodal tsDCS over lumbar segments may facilitate proprioceptive transcortical reflexes in the TA muscle, and we suggest that the most likely explanation of this facilitation is an effect on ascending fibers in the dorsal columns.
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Affiliation(s)
- Eva Rudjord Therkildsen
- Department of Neuroscience, Panum Institute 33.3, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
| | - Jens Bo Nielsen
- Department of Neuroscience, Panum Institute 33.3, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.,Elsass Foundation, Holmegaardsvej 28, 2920, Charlottenlund, Denmark
| | - Mikkel Malling Beck
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Nørre Allé 51, 2200, Copenhagen, Denmark
| | - Tomofumi Yamaguchi
- Department of Neuroscience, Panum Institute 33.3, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.,Department of Physical Therapy, Faculty of Health Science, Juntendo University, 2-1-1Bunkyo-ku, HongoTokyo, Japan
| | - Jakob Lorentzen
- Department of Neuroscience, Panum Institute 33.3, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
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Megía-García Á, Serrano-Muñoz D, Comino-Suárez N, Del-Ama AJ, Moreno JC, Gil-Agudo A, Taylor J, Gómez-Soriano J. Effect of posture and body weight loading on spinal posterior root reflex responses. Eur J Neurosci 2021; 54:6575-6586. [PMID: 34494329 DOI: 10.1111/ejn.15448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 11/30/2022]
Abstract
The posterior root muscle response (PRM) is a monosynaptic reflex that is evoked by single pulse transcutaneous spinal cord stimulation (tSCS). The main aim of this work was to analyse how body weight loading influences PRM reflex threshold measured from several lower limb muscles in healthy participants. PRM reflex responses were evoked with 1-ms rectangular monophasic pulses applied at an interval of 6 s via a self-adhesive electrode (9 × 5 cm) at the T11-T12 vertebral level. Surface electromyographic activity of lower limb muscles was recorded during four different conditions, one in decubitus supine (DS) and the other three involving standing at 100%, 50%, and 0% body weight loading (BW). PRM threshold intensity, peak-to-peak amplitude, and latency for each muscle were analysed in different conditions study. PRM reflex threshold increased with body weight unloading compared with DS, and the largest change was observed between DS and 0% BW for the proximal muscles and between DS and 50% BW for distal muscles. Peak-to-peak amplitude analysis showed only a significant mean decrease of 34.6% (SD 10.4, p = 0.028) in TA and 53.6% (SD 15.1, p = 0.019) in GM muscles between DS and 50% BW. No significant differences were observed for PRM latency. This study has shown that sensorimotor networks can be activated with tSCS in various conditions of body weight unloading. Higher stimulus intensities are necessary to evoke reflex response during standing at 50% body weight loading. These results have practical implications for gait rehabilitation training programmes that include body weight support.
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Affiliation(s)
- Álvaro Megía-García
- Biomechanical and Technical Aids Unit, National Hospital for Paraplegia, SESCAM, Toledo, Spain.,Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing, Castilla La Mancha University, Toledo, Spain
| | - Diego Serrano-Muñoz
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing, Castilla La Mancha University, Toledo, Spain
| | - Natalia Comino-Suárez
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
| | - Antonio J Del-Ama
- Biomechanical and Technical Aids Unit, National Hospital for Paraplegia, SESCAM, Toledo, Spain.,Rey Juan Carlos University, Madrid, Spain
| | - Juan C Moreno
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
| | - Angel Gil-Agudo
- Biomechanical and Technical Aids Unit, National Hospital for Paraplegia, SESCAM, Toledo, Spain
| | - Julian Taylor
- Sensorimotor Function Group, National Hospital for Paraplegia, SESCAM, Toledo, Spain.,Harris Manchester College, University of Oxford, Oxford, UK
| | - Julio Gómez-Soriano
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing, Castilla La Mancha University, Toledo, Spain
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Martins Â, Gouveia D, Cardoso A, Carvalho C, Silva C, Coelho T, Gamboa Ó, Ferreira A. Functional Neurorehabilitation in Dogs with an Incomplete Recovery 3 Months following Intervertebral Disc Surgery: A Case Series. Animals (Basel) 2021; 11:ani11082442. [PMID: 34438900 PMCID: PMC8388785 DOI: 10.3390/ani11082442] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 12/27/2022] Open
Abstract
Simple Summary A non-invasive neurorehabilitation multimodal protocol (NRMP) may be applicable to chronic T3-L3 dogs 3 months after undergoing surgery for acute Intervertebral Disc Disease (IVDD) Hansen type I; this protocol has been shown to be safe, feasible, and potentially effective at improving ambulation in both open field score (OFS) 0 and OFS 1 dogs. The specific sample population criteria limit the number of dogs included, mainly due to owners withdrawing over time. Thus, the present case series study aimed to demonstrate that an NRMP could contribute to a functional treatment possibly based on synaptic and anatomic reorganization of the spinal cord. Abstract This case series study aimed to evaluate the safety, feasibility, and positive outcome of the neurorehabilitation multimodal protocol (NRMP) in 16 chronic post-surgical IVDD Hansen type I dogs, with OFS 0/DPP− (n = 9) and OFS 1/DPP+ (n = 7). All were enrolled in the NRMP for a maximum of 90 days and were clinically discharged after achieving ambulation. The NRMP was based on locomotor training, functional electrical stimulation, transcutaneous electrical spinal cord stimulation, and 4-aminopyridine (4-AP) pharmacological management. In the Deep Pain Perception (DPP)+ dogs, 100% recovered ambulation within a mean period of 47 days, reaching OFS ≥11, which suggests that a longer period of time is needed for recovery. At follow-up, all dogs presented a positive evolution with voluntary micturition. Of the DPP− dogs admitted, all achieved a flexion/extension locomotor pattern within 30 days, and after starting the 4-AP, two dogs were discharged at outcome day 45, with 78% obtaining Spinal Reflex Locomotion (SRL) and automatic micturition within a mean period of 62 days. At follow-up, all dogs maintained their neurological status. After the NRMP, ambulatory status was achieved in 88% (14/16) of dogs, without concurrent events. Thus, an NRMP may be an important therapeutic option to reduce the need for euthanasia in the clinical setting.
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Affiliation(s)
- Ângela Martins
- Faculty of Veterinary Medicine, Lusófona University, Campo Grande, 1300-477 Lisboa, Portugal
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
- Correspondence:
| | - Débora Gouveia
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
| | - Ana Cardoso
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Carla Carvalho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Cátia Silva
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Tiago Coelho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Óscar Gamboa
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
| | - António Ferreira
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
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