1
|
Debenham MIB, Franz CK, Berger MJ. Neuromuscular consequences of spinal cord injury: New mechanistic insights and clinical considerations. Muscle Nerve 2024; 70:12-27. [PMID: 38477416 DOI: 10.1002/mus.28070] [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: 10/20/2023] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 03/14/2024]
Abstract
The spinal cord facilitates communication between the brain and the body, containing intrinsic systems that work with lower motor neurons (LMNs) to manage movement. Spinal cord injuries (SCIs) can lead to partial paralysis and dysfunctions in muscles below the injury. While traditionally this paralysis has been attributed to disruptions in the corticospinal tract, a growing body of work demonstrates LMN damage is a factor. Motor units, comprising the LMN and the muscle fibers with which they connect, are essential for voluntary movement. Our understanding of their changes post-SCI is still emerging, but the health of motor units is vital, especially when considering innovative SCI treatments like nerve transfer surgery. This review seeks to collate current literature on how SCI impact motor units and explore neuromuscular clinical implications and treatment avenues. SCI reduced motor unit number estimates, and surviving motor units had impaired signal transmission at the neuromuscular junction, force-generating capacity, and excitability, which have the potential to recover chronically, yet the underlaying mechanisms are unclear. Furthermore, electrodiagnostic evaluations can aid in assessing the health lower and upper motor neurons, identify suitable targets for nerve transfer surgeries, and detect patients with time sensitive injuries. Lastly, many electrodiagnostic abnormalities occur in both chronic and acute SCI, yet factors contributing to these abnormalities are unknown. Future studies are required to determine how motor units adapt following SCI and the clinical implications of these adaptations.
Collapse
Affiliation(s)
- Mathew I B Debenham
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin K Franz
- Biologics Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois, USA
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
2
|
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 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.
Collapse
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
| |
Collapse
|
3
|
Malloy DC, Côté MP. Multi-session transcutaneous spinal cord stimulation prevents chloride homeostasis imbalance and the development of hyperreflexia after spinal cord injury in rat. Exp Neurol 2024; 376:114754. [PMID: 38493983 DOI: 10.1016/j.expneurol.2024.114754] [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: 12/01/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.
Collapse
Affiliation(s)
- Dillon C Malloy
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
| |
Collapse
|
4
|
Kumru H, Ros-Alsina A, García Alén L, Vidal J, Gerasimenko Y, Hernandez A, Wrigth M. Improvement in Motor and Walking Capacity during Multisegmental Transcutaneous Spinal Stimulation in Individuals with Incomplete Spinal Cord Injury. Int J Mol Sci 2024; 25:4480. [PMID: 38674065 PMCID: PMC11050444 DOI: 10.3390/ijms25084480] [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: 03/28/2024] [Revised: 04/12/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Transcutaneous multisegmental spinal cord stimulation (tSCS) has shown superior efficacy in modulating spinal locomotor circuits compared to single-site stimulation in individuals with spinal cord injury (SCI). Building on these findings, we hypothesized that administering a single session of tSCS at multiple spinal segments may yield greater enhancements in muscle strength and gait function during stimulation compared to tSCS at only one or two segments. In our study, tSCS was applied at single segments (C5, L1, and Coc1), two segments (C5-L1, C5-Coc1, and L1-Coc1), or multisegments (C5-L1-Coc1) in a randomized order. We evaluated the 6-m walking test (6MWT) and maximum voluntary contraction (MVC) and assessed the Hmax/Mmax ratio during stimulation in ten individuals with incomplete motor SCI. Our findings indicate that multisegmental tSCS improved walking time and reduced spinal cord excitability, as measured by the Hmax/Mmax ratio, similar to some single or two-site tSCS interventions. However, only multisegmental tSCS resulted in increased tibialis anterior (TA) muscle strength. These results suggest that multisegmental tSCS holds promise for enhancing walking capacity, increasing muscle strength, and altering spinal cord excitability in individuals with incomplete SCI.
Collapse
Affiliation(s)
- Hatice Kumru
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
- Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| | - Aina Ros-Alsina
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
| | - Loreto García Alén
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
- Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| | - Joan Vidal
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
- Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| | - Yury Gerasimenko
- Pavlov Institute of Physiology, St. Petersburg 199034, Russia;
- Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40292, USA
| | - Agusti Hernandez
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
- Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| | - Mark Wrigth
- Fundación Institut Guttmann, Institut Universitari de NeurorehabilitacióAdscrit a la UAB, 08916 Badalona, Spain; (A.R.-A.); (L.G.A.); (J.V.); (A.H.); (M.W.)
- Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| |
Collapse
|
5
|
Moon Y, Yang C, Veit NC, McKenzie KA, Kim J, Aalla S, Yingling L, Buchler K, Hunt J, Jenz S, Shin SY, Kishta A, Edgerton VR, Gerasimenko YP, Roth EJ, Lieber RL, Jayaraman A. Noninvasive spinal stimulation improves walking in chronic stroke survivors: a proof-of-concept case series. Biomed Eng Online 2024; 23:38. [PMID: 38561821 PMCID: PMC10986021 DOI: 10.1186/s12938-024-01231-1] [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: 01/09/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND After stroke, restoring safe, independent, and efficient walking is a top rehabilitation priority. However, in nearly 70% of stroke survivors asymmetrical walking patterns and reduced walking speed persist. This case series study aims to investigate the effectiveness of transcutaneous spinal cord stimulation (tSCS) in enhancing walking ability of persons with chronic stroke. METHODS Eight participants with hemiparesis after a single, chronic stroke were enrolled. Each participant was assigned to either the Stim group (N = 4, gait training + tSCS) or Control group (N = 4, gait training alone). Each participant in the Stim group was matched to a participant in the Control group based on age, time since stroke, and self-selected gait speed. For the Stim group, tSCS was delivered during gait training via electrodes placed on the skin between the spinous processes of C5-C6, T11-T12, and L1-L2. Both groups received 24 sessions of gait training over 8 weeks with a physical therapist providing verbal cueing for improved gait symmetry. Gait speed (measured from 10 m walk test), endurance (measured from 6 min walk test), spatiotemporal gait symmetries (step length and swing time), as well as the neurophysiological outcomes (muscle synergy, resting motor thresholds via spinal motor evoked responses) were collected without tSCS at baseline, completion, and 3 month follow-up. RESULTS All four Stim participants sustained spatiotemporal symmetry improvements at the 3 month follow-up (step length: 17.7%, swing time: 10.1%) compared to the Control group (step length: 1.1%, swing time 3.6%). Additionally, 3 of 4 Stim participants showed increased number of muscle synergies and/or lowered resting motor thresholds compared to the Control group. CONCLUSIONS This study provides promising preliminary evidence that using tSCS as a therapeutic catalyst to gait training may increase the efficacy of gait rehabilitation in individuals with chronic stroke. Trial registration NCT03714282 (clinicaltrials.gov), registration date: 2018-10-18.
Collapse
Affiliation(s)
- Yaejin Moon
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Department of Exercise Science, Syracuse University, Syracuse, NY, 13057, USA
| | - Chen Yang
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Nicole C Veit
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Biomedical Engineering Department, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Kelly A McKenzie
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Jay Kim
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Shreya Aalla
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Lindsey Yingling
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Kristine Buchler
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Jasmine Hunt
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - Sophia Jenz
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Sung Yul Shin
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Ameen Kishta
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
| | - V Reggie Edgerton
- Rancho Los Amigos National Rehabilitation Center, Broccoli Impossible-to-Possible Lab, Rancho Research Institute, Downy, CA, 90242, USA
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Yury P Gerasimenko
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Pavlov Institute of Physiology, St. Petersburg, Russia
| | - Elliot J Roth
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Richard L Lieber
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Hines VA Medical Center, Maywood, IL, 60141, USA
| | - Arun Jayaraman
- Shirley Ryan AbilityLab, 355 E. Erie St, Chicago, IL, 60611, USA.
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
| |
Collapse
|
6
|
Tajali S, Balbinot G, Pakosh M, Sayenko DG, Zariffa J, Masani K. Modulations in neural pathways excitability post transcutaneous spinal cord stimulation among individuals with spinal cord injury: a systematic review. Front Neurosci 2024; 18:1372222. [PMID: 38591069 PMCID: PMC11000807 DOI: 10.3389/fnins.2024.1372222] [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: 01/17/2024] [Accepted: 03/06/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction Transcutaneous spinal cord stimulation (TSCS), a non-invasive form of spinal cord stimulation, has been shown to improve motor function in individuals living with spinal cord injury (SCI). However, the effects of different types of TSCS currents including direct current (DC-TSCS), alternating current (AC-TSCS), and spinal paired stimulation on the excitability of neural pathways have not been systematically investigated. The objective of this systematic review was to determine the effects of TSCS on the excitability of neural pathways in adults with non-progressive SCI at any level. Methods The following databases were searched from their inception until June 2022: MEDLINE ALL, Embase, Web of Science, Cochrane Library, and clinical trials. A total of 4,431 abstracts were screened, and 23 articles were included. Results Nineteen studies used TSCS at the thoracolumbar enlargement for lower limb rehabilitation (gait & balance) and four studies used cervical TSCS for upper limb rehabilitation. Sixteen studies measured spinal excitability by reporting different outcomes including Hoffmann reflex (H-reflex), flexion reflex excitability, spinal motor evoked potentials (SMEPs), cervicomedullay evoked potentials (CMEPs), and cutaneous-input-evoked muscle response. Seven studies measured corticospinal excitability using motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS), and one study measured somatosensory evoked potentials (SSEPs) following TSCS. Our findings indicated a decrease in the amplitude of H-reflex and long latency flexion reflex following AC-TSCS, alongside an increase in the amplitudes of SMEPs and CMEPs. Moreover, the application of the TSCS-TMS paired associative technique resulted in spinal reflex inhibition, manifested by reduced amplitudes in both the H-reflex and flexion reflex arc. In terms of corticospinal excitability, findings from 5 studies demonstrated an increase in the amplitude of MEPs linked to lower limb muscles following DC-TSCS, in addition to paired associative stimulation involving repetitive TMS on the brain and DC-TSCS on the spine. There was an observed improvement in the latency of SSEPs in a single study. Notably, the overall quality of evidence, assessed by the modified Downs and Black Quality assessment, was deemed poor. Discussion This review unveils the systematic evidence supporting the potential of TSCS in reshaping both spinal and supraspinal neuronal circuitries post-SCI. Yet, it underscores the critical necessity for more rigorous, high-quality investigations.
Collapse
Affiliation(s)
- Shirin Tajali
- KITE Research Institute – University Health Network, Toronto, ON, Canada
| | - Gustavo Balbinot
- KITE Research Institute – University Health Network, Toronto, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Center for Advancing Neurotechnological Innovation to Application – CRANIA, University Health Network, Toronto, ON, Canada
| | - Maureen Pakosh
- Library & Information Services, University Health Network, Toronto Rehabilitation Institute, ON, Canada
| | - Dimitry G. Sayenko
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX, United States
| | - Jose Zariffa
- KITE Research Institute – University Health Network, Toronto, ON, Canada
- Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada
| | - Kei Masani
- KITE Research Institute – University Health Network, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
7
|
Malloy DC, Côté MP. Multi-session transcutaneous spinal cord stimulation prevents chloridehomeostasis imbalance and the development of spasticity after spinal cordinjury in rat. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563419. [PMID: 37961233 PMCID: PMC10634766 DOI: 10.1101/2023.10.24.563419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.
Collapse
Affiliation(s)
- Dillon C. Malloy
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| |
Collapse
|
8
|
Shackleton C, Samejima S, Williams AM, Malik RN, Balthazaar SJ, Alrashidi A, Sachdeva R, Elliott SL, Nightingale TE, Berger MJ, Lam T, Krassioukov AV. Motor and autonomic concomitant health improvements with neuromodulation and exercise (MACHINE) training: a randomised controlled trial in individuals with spinal cord injury. BMJ Open 2023; 13:e070544. [PMID: 37451734 PMCID: PMC10351300 DOI: 10.1136/bmjopen-2022-070544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 06/21/2023] [Indexed: 07/18/2023] Open
Abstract
INTRODUCTION Motor and autonomic dysfunctions are widespread among people with spinal cord injury (SCI), leading to poor health and reduced quality of life. Exercise interventions, such as locomotor training (LT), can promote sensorimotor and autonomic recovery post SCI. Recently, breakthroughs in SCI research have reported beneficial effects of electrical spinal cord stimulation (SCS) on motor and autonomic functions. Despite literature supporting the independent benefits of transcutaneous SCS (TSCS) and LT, the effect of pairing TSCS with LT is unknown. These therapies are non-invasive, customisable and have the potential to simultaneously benefit both sensorimotor and autonomic functions. The aim of this study is to assess the effects of LT paired with TSCS in people with chronic SCI on outcomes of sensorimotor and autonomic function. METHODS AND ANALYSIS Twelve eligible participants with chronic (>1 year) motor-complete SCI, at or above the sixth thoracic segment, will be enrolled in this single-blinded, randomised sham-controlled trial. Participants will undergo mapping for optimisation of stimulation parameters and baseline assessments of motor and autonomic functions. Participants will then be randomly assigned to either LT+TSCS or LT+Sham stimulation for 12 weeks, after which postintervention assessments will be performed to determine the effect of TSCS on motor and autonomic functions. The primary outcome of interest is attempted voluntary muscle activation using surface electromyography. The secondary outcomes relate to sensorimotor function, cardiovascular function, pelvic organ function and health-related quality of life. Statistical analysis will be performed using two-way repeated measures Analysis of variance (ANOVAs) or Kruskal-Wallis and Cohen's effect sizes. ETHICS AND DISSEMINATION This study has been approved after full ethical review by the University of British Columbia's Research Ethics Board. The stimulator used in this trial has received Investigation Testing Authorisation from Health Canada. Trial results will be disseminated through peer-reviewed publications, conference presentations and seminars. TRIAL REGISTRATION NUMBER NCT04726059.
Collapse
Affiliation(s)
- Claire Shackleton
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Soshi Samejima
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Alison Mm Williams
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Raza N Malik
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Shane Jt Balthazaar
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Division of Cardiology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Abdullah Alrashidi
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physical Therapy, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Rahul Sachdeva
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Stacy L Elliott
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- GF Strong Rehabilitation Centre, Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
- Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas E Nightingale
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- School of Sport, Exercise and Rehabilitation Sciences and Centre for Trauma Science Research, University of Birmingham, Birmingham, UK
- Centre for Trauma Science Research, University of Birmingham, Birmingham, UK
| | - Michael J Berger
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Tania Lam
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
- GF Strong Rehabilitation Centre, Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
| |
Collapse
|
9
|
Skiadopoulos A, Famodimu GO, Solomon SK, Agarwal P, Harel NY, Knikou M. Priming locomotor training with transspinal stimulation in people with spinal cord injury: study protocol of a randomized clinical trial. Trials 2023; 24:145. [PMID: 36841773 PMCID: PMC9960224 DOI: 10.1186/s13063-023-07193-4] [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: 02/01/2023] [Accepted: 02/20/2023] [Indexed: 02/27/2023] Open
Abstract
BACKGROUND The seemingly simple tasks of standing and walking require continuous integration of complex spinal reflex circuits between descending motor commands and ascending sensory inputs. Spinal cord injury greatly impairs standing and walking ability, but both improve with locomotor training. However, even after multiple locomotor training sessions, abnormal muscle activity and coordination persist. Thus, locomotor training alone cannot fully optimize the neuronal plasticity required to strengthen the synapses connecting the brain, spinal cord, and local circuits and potentiate neuronal activity based on need. Transcutaneous spinal cord (transspinal) stimulation alters motoneuron excitability over multiple segments by bringing motoneurons closer to threshold, a prerequisite for effectively promoting spinal locomotor network neuromodulation and strengthening neural connectivity of the injured human spinal cord. Importantly, whether concurrent treatment with transspinal stimulation and locomotor training maximizes motor recovery after spinal cord injury is unknown. METHODS Forty-five individuals with chronic spinal cord injury are receiving 40 sessions of robotic gait training primed with 30 Hz transspinal stimulation at the Thoracic 10 vertebral level. Participants are randomized to receive 30 min of active or sham transspinal stimulation during standing or active transspinal stimulation while supine followed by 30 min of robotic gait training. Over the course of locomotor training, the body weight support, treadmill speed, and leg guidance force are adjusted as needed for each participant based on absence of knee buckling during the stance phase and toe dragging during the swing phase. At baseline and after completion of all therapeutic sessions, neurophysiological recordings registering corticospinal and spinal neural excitability changes along with clinical assessment measures of standing and walking, and autonomic function via questionnaires regarding bowel, bladder, and sexual function are taken. DISCUSSION The results of this mechanistic randomized clinical trial will demonstrate that tonic transspinal stimulation strengthens corticomotoneuronal connectivity and dynamic neuromodulation through posture-dependent corticospinal and spinal neuroplasticity. We anticipate that this mechanistic clinical trial will greatly impact clinical practice because, in real-world clinical settings, noninvasive transspinal stimulation can be more easily and widely implemented than invasive epidural stimulation. Additionally, by applying multiple interventions to accelerate motor recovery, we are employing a treatment regimen that reflects a true clinical approach. TRIAL REGISTRATION ClinicalTrials.gov NCT04807764 . Registered on March 19, 2021.
Collapse
Affiliation(s)
- Andreas Skiadopoulos
- grid.254498.60000 0001 2198 5185Klab4Recovery Research Program, The City University of New York, College of Staten Island, Staten Island, NY USA ,grid.254498.60000 0001 2198 5185Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY USA
| | - Grace O. Famodimu
- Spinal Cord Damage Research Center, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY USA
| | - Shammah K. Solomon
- grid.254498.60000 0001 2198 5185Klab4Recovery Research Program, The City University of New York, College of Staten Island, Staten Island, NY USA ,grid.254498.60000 0001 2198 5185Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY USA
| | - Parul Agarwal
- grid.59734.3c0000 0001 0670 2351Population Health Science & Policy, Institute for Health Care Delivery Science, Icahn School of Medicine at Mount Sinai, Manhattan, NY USA
| | - Noam Y. Harel
- Spinal Cord Damage Research Center, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY USA ,grid.59734.3c0000 0001 0670 2351Population Health Science & Policy, Institute for Health Care Delivery Science, Icahn School of Medicine at Mount Sinai, Manhattan, NY USA
| | - Maria Knikou
- Klab4Recovery Research Program, The City University of New York, College of Staten Island, Staten Island, NY, USA. .,Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY, USA. .,PhD Program in Biology and Collaborative Neuroscience Program, Graduate Center of The City University of New York and College of Staten Island, Manhattan & Staten Island, NY, USA.
| |
Collapse
|
10
|
Skiadopoulos A, Famodimu GO, Solomon SK, Agrawal P, Harel NY, Knikou M. Priming locomotor training with transspinal stimulation in people with spinal cord injury: study protocol of a randomized clinical trial. RESEARCH SQUARE 2023:rs.3.rs-2527617. [PMID: 36824823 PMCID: PMC9949167 DOI: 10.21203/rs.3.rs-2527617/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Background The seemingly simple tasks of standing and walking require continuous integration of complex spinal reflex circuits between descending motor commands and ascending sensory inputs. Spinal cord injury greatly impairs standing and walking ability, but both improve with locomotor training. However, even after multiple locomotor training sessions, abnormal muscle activity and coordination persist. Thus, locomotor training alone cannot fully optimize the neuronal plasticity required to strengthen the synapses connecting the brain, spinal cord, and local circuits and potentiate neuronal activity based on need. Transcutaneous spinal cord (transspinal) stimulation alters motoneuron excitability over multiple segments by bringing motoneurons closer to threshold, a prerequisite for effectively promoting spinal locomotor network neuromodulation and strengthening neural connectivity of the injured human spinal cord. Importantly, whether concurrent treatment with transspinal stimulation and locomotor training maximizes motor recovery after spinal cord injury is unknown. Methods Forty-five individuals with chronic spinal cord injury are receiving 40 sessions of robotic gait training primed with 30 Hz transspinal stimulation at the Thoracic 10 vertebral level. Participants are randomized to receive 30-minutes of active or sham transspinal stimulation during standing or active transspinal stimulation while supine followed by 30-minutes of robotic gait training. Over the course of locomotor training, the body weight support, treadmill speed, and leg guidance force are adjusted as needed for each participant based on absence of knee buckling during the stance phase and toe dragging during the swing phase. At baseline and after completion of all therapeutic sessions, neurophysiological recordings registering corticospinal and spinal neural excitability changes along with clinical assessment measures of standing and walking, and autonomic function via questionnaires regarding bowel, bladder and sexual function are taken. Discussion The results of this mechanistic randomized clinical trial will demonstrate that tonic transspinal stimulation strengthens corticomotoneuronal connectivity and dynamic neuromodulation through posture-dependent corticospinal and spinal neuroplasticity. We anticipate that this mechanistic clinical trial will greatly impact clinical practice because in real-world clinical settings, noninvasive transspinal stimulation can be more easily and widely implemented than invasive epidural stimulation. Additionally, by applying multiple interventions to accelerate motor recovery, we are employing a treatment regimen that reflects a true clinical approach. Trial registration ClinicalTrials.gov: NCT04807764; Registered on March 19, 2021.
Collapse
Affiliation(s)
| | | | | | - Parul Agrawal
- Icahn School of Medicine at Mount Sinai Department of Population Health Science and Policy
| | - Noam Y Harel
- James J Peters VAMC: James J Peters VA Medical Center
| | - Maria Knikou
- College of Staten Island School of Health Sciences
| |
Collapse
|
11
|
Neuromodulation with transcutaneous spinal stimulation reveals different groups of motor profiles during robot-guided stepping in humans with incomplete spinal cord injury. Exp Brain Res 2023; 241:365-382. [PMID: 36534141 PMCID: PMC10278039 DOI: 10.1007/s00221-022-06521-5] [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: 08/16/2022] [Accepted: 12/03/2022] [Indexed: 12/23/2022]
Abstract
Neuromodulation via spinal stimulation has been investigated for improving motor function and reducing spasticity after spinal cord injury (SCI) in humans. Despite the reported heterogeneity of outcomes, few investigations have attempted to discern commonalities among individual responses to neuromodulation, especially the impact of stimulation frequencies. Here, we examined how exposure to continuous lumbosacral transcutaneous spinal stimulation (TSS) across a range of frequencies affects robotic torques and EMG patterns during stepping in a robotic gait orthosis on a motorized treadmill. We studied nine chronic motor-incomplete SCI individuals (8/1 AIS-C/D, 8 men) during robot-guided stepping with body-weight support without and with TSS applied at random frequencies between 1 and up to 100 Hz at a constant, individually selected stimulation intensity below the common motor threshold for posterior root reflexes. The hip and knee robotic torques needed to maintain the predefined stepping trajectory and EMG in eight bilateral leg muscles were recorded. We calculated the standardized mean difference between the stimulation conditions grouped into frequency bins and the no stimulation condition to determine changes in the normalized torques and the average EMG envelopes. We found heterogeneous changes in robotic torques across individuals. Agglomerative clustering of robotic torques identified four groups wherein the patterns of changes differed in magnitude and direction depending mainly on the stimulation frequency and stance/swing phase. On one end of the spectrum, the changes in robotic torques were greater with increasing stimulation frequencies (four participants), which coincided with a decrease in EMG, mainly due to the reduction of clonogenic motor output in the lower leg muscles. On the other end, we found an inverted u-shape change in torque over the mid-frequency range along with an increase in EMG, reflecting the augmentation of gait-related physiological (two participants) or pathophysiological (one participant) output. We conclude that TSS during robot-guided stepping reveals different frequency-dependent motor profiles among individuals with chronic motor incomplete SCI. This suggests the need for a better understanding and characterization of motor control profiles in SCI when applying TSS as a therapeutic intervention for improving gait.
Collapse
|
12
|
Dalrymple AN, Hooper CA, Kuriakose MG, Capogrosso M, Weber DJ. Using a high-frequency carrier does not improve comfort of transcutaneous spinal cord stimulation. J Neural Eng 2023; 20. [PMID: 36595241 DOI: 10.1088/1741-2552/acabe8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Objective.Spinal cord neuromodulation has gained much attention for demonstrating improved motor recovery in people with spinal cord injury, motivating the development of clinically applicable technologies. Among them, transcutaneous spinal cord stimulation (tSCS) is attractive because of its non-invasive profile. Many tSCS studies employ a high-frequency (10 kHz) carrier, which has been reported to reduce stimulation discomfort. However, these claims have come under scrutiny in recent years. The purpose of this study was to determine whether using a high-frequency carrier for tSCS is more comfortable at therapeutic amplitudes, which evoke posterior root-muscle (PRM) reflexes.Approach.In 16 neurologically intact participants, tSCS was delivered using a 1 ms long monophasic pulse with and without a high-frequency carrier. Stimulation amplitude and pulse duration were varied and PRM reflexes were recorded from the soleus, gastrocnemius, and tibialis anterior muscles. Participants rated their discomfort during stimulation from 0 to 10 at PRM reflex threshold.Main Results.At PRM reflex threshold, the addition of a high-frequency carrier (0.87 ± 0.2) was equally comfortable as conventional stimulation (1.03 ± 0.18) but required approximately double the charge to evoke the PRM reflex (conventional: 32.4 ± 9.2µC; high-frequency carrier: 62.5 ± 11.1µC). Strength-duration curves for tSCS with a high-frequency carrier had a rheobase that was 4.8× greater and a chronaxie that was 5.7× narrower than the conventional monophasic pulse, indicating that the addition of a high-frequency carrier makes stimulation less efficient in recruiting neural activity in spinal roots.Significance.Using a high-frequency carrier for tSCS is equally as comfortable and less efficient as conventional stimulation at amplitudes required to stimulate spinal dorsal roots.
Collapse
Affiliation(s)
- Ashley N Dalrymple
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Charli Ann Hooper
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Minna G Kuriakose
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Marco Capogrosso
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, United States of America.,Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Douglas J Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America.,NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America.,Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, United States of America
| |
Collapse
|
13
|
Chakraborty A, Sharma MC, Vishnubhatla S, Jain S. Electromagnetic field stimulation facilitates motor neuron excitability, myogenesis and muscle contractility in spinal cord transected rats. J Biosci 2022. [DOI: 10.1007/s12038-022-00318-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
14
|
Pulverenti TS, Zaaya M, Grabowski E, Grabowski M, Knikou M. Brain and spinal cord paired stimulation coupled with locomotor training facilitates motor output in human spinal cord injury. Front Neurol 2022; 13:1000940. [PMID: 36313489 PMCID: PMC9612520 DOI: 10.3389/fneur.2022.1000940] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/26/2022] [Indexed: 11/21/2022] Open
Abstract
Combined interventions for neuromodulation leading to neurorecovery have gained great attention by researchers to resemble clinical rehabilitation approaches. In this randomized clinical trial, we established changes in the net output of motoneurons innervating multiple leg muscles during stepping when transcranial magnetic stimulation (TMS) of the primary motor cortex was paired with transcutaneous spinal (transspinal) stimulation over the thoracolumbar region during locomotor training. TMS was delivered before (TMS-transspinal) or after (transspinal-TMS) transspinal stimulation during the stance phase of the less impaired leg. Ten individuals with chronic incomplete or complete SCI received at least 20 sessions of training. Each session consisted of 240 paired stimuli delivered over 10-min blocks for 1 h during robotic assisted step training on a motorized treadmill. Body weight support, leg guidance force and treadmill speed were adjusted based on each subject's ability to step without knee buckling or toe dragging. Most transspinal evoked potentials (TEPs) recorded before and after each intervention from ankle and knee muscles during assisted stepping were modulated in a phase-dependent pattern. Transspinal-TMS and locomotor training affected motor neuron output of knee and ankle muscles with ankle TEPs to be modulated in a phase-dependent manner. TMS-transspinal and locomotor training increased motor neuron output for knee but not for ankle muscles. Our results support that targeted brain and spinal cord stimulation alters responsiveness of neurons over multiple spinal segments in people with chronic SCI. Noninvasive stimulation of the brain and spinal cord along with locomotor training is a novel neuromodulation method that can become a promising modality for rehabilitation in humans after SCI.
Collapse
Affiliation(s)
- Timothy S. Pulverenti
- Klab4Recovery Research Program, The City University of New York, New York, NY, United States
| | - Morad Zaaya
- Klab4Recovery Research Program, The City University of New York, New York, NY, United States
| | - Ewelina Grabowski
- PhD Program in Biology and Collaborative Neuroscience Program, Graduate Center of the City University of New York and College of Staten Island, New York, NY, United States
| | - Monika Grabowski
- PhD Program in Biology and Collaborative Neuroscience Program, Graduate Center of the City University of New York and College of Staten Island, New York, NY, United States
| | - Maria Knikou
- Klab4Recovery Research Program, The City University of New York, New York, NY, 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, NY, United States,Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States,*Correspondence: Maria Knikou
| |
Collapse
|
15
|
Brain and spinal cord paired stimulation coupled with locomotor training affects polysynaptic flexion reflex circuits in human spinal cord injury. Exp Brain Res 2022; 240:1687-1699. [PMID: 35513720 DOI: 10.1007/s00221-022-06375-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 04/15/2022] [Indexed: 12/19/2022]
Abstract
Neurorecovery from locomotor training is well established in human spinal cord injury (SCI). However, neurorecovery resulting from combined interventions has not been widely studied. In this randomized clinical trial, we established the tibialis anterior (TA) flexion reflex modulation pattern when transcranial magnetic stimulation (TMS) of the primary motor cortex was paired with transcutaneous spinal cord (transspinal) stimulation over the thoracolumbar region during assisted step training. Single pulses of TMS were delivered either before (TMS-transspinal) or after (transspinal-TMS) transspinal stimulation during the stance phase of the less impaired leg. Eight individuals with chronic incomplete or complete SCI received at least 20 sessions of paired stimulation during assisted step training. Each session consisted of 240 paired stimuli delivered over 10-min blocks for 1 h during robotic-assisted step training with the Lokomat6 Pro®. Body weight support, leg guidance force and treadmill speed were adjusted based on each participant's ability to step without knee buckling or toe dragging. Both the early and late TA flexion reflex remained unaltered after TMS-transspinal and locomotor training. In contrast, the early and late TA flexion reflexes were significantly depressed during stepping after transspinal-TMS and locomotor training. Reflex changes occurred at similar slopes and intercepts before and after training. Our findings support that targeted brain and spinal cord stimulation coupled with locomotor training reorganizes the function of flexion reflex pathways, which are a part of locomotor networks, in humans with varying levels of sensorimotor function after SCI.Trial registration number NCT04624607; Registered on November 12, 2020.
Collapse
|
16
|
Adapting Human-Based Transcutaneous Spinal Cord Stimulation to Develop a Clinically Relevant Animal Model. J Clin Med 2022; 11:jcm11072023. [PMID: 35407636 PMCID: PMC8999945 DOI: 10.3390/jcm11072023] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/01/2023] Open
Abstract
Transcutaneous spinal cord stimulation (tSCS) as a neuromodulatory strategy has received great attention as a method to promote functional recovery after spinal cord injury (SCI). However, due to the noninvasive nature of tSCS, investigations have primarily focused on human applications. This leaves a critical need for the development of a suitable animal model to further our understanding of this therapeutic intervention in terms of functional and neuroanatomical plasticity and to optimize stimulation protocols. The objective of this study is to establish a new animal model of thoracolumbar tSCS that (1) can accurately recapitulate studies in healthy humans and (2) can receive a repeated and stable tSCS treatment after SCI with minimal restraint, while the electrode remains consistently positioned. We show that our model displays bilateral evoked potentials in multisegmental leg muscles characteristically comparable to humans. Our data also suggest that tSCS mainly activates dorsal root structures like in humans, thereby accounting for the different electrode-to-body-size ratio between the two species. Finally, a repeated tSCS treatment protocol in the awake rat after a complete spinal cord transection is feasible, tolerable, and safe, even with minimal body restraint. Additionally, repeated tSCS was capable of modulating motor output after SCI, providing an avenue to further investigate stimulation-based neuroplasticity and optimize treatment.
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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: 6] [Impact Index Per Article: 2.0] [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.
Collapse
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
| |
Collapse
|
19
|
de Freitas RM, Sasaki A, Sayenko DG, Masugi Y, Nomura T, Nakazawa K, Milosevic M. Selectivity and excitability of upper-limb muscle activation during cervical transcutaneous spinal cord stimulation in humans. J Appl Physiol (1985) 2021; 131:746-759. [PMID: 34138648 DOI: 10.1152/japplphysiol.00132.2021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cervical transcutaneous spinal cord stimulation (tSCS) efficacy for rehabilitation of upper-limb motor function was suggested to depend on recruitment of Ia afferents. However, selectivity and excitability of motor activation with different electrode configurations remain unclear. In this study, activation of upper-limb motor pools was examined with different cathode and anode configurations during cervical tSCS in 10 able-bodied individuals. Muscle responses were measured from six upper-limb muscles simultaneously. First, postactivation depression was confirmed with tSCS paired pulses (50-ms interval) for each cathode configuration (C6, C7, and T1 vertebral levels), with anode on the anterior neck. Selectivity and excitability of activation of the upper-limb motor pools were examined by comparing the recruitment curves (10-100 mA) of first evoked responses across muscles and cathode configurations. Our results showed that hand muscles were preferentially activated when the cathode was placed over T1 compared with the other vertebral levels, whereas there was no selectivity for proximal arm muscles. Furthermore, higher stimulation intensities were required to activate distal hand muscles than proximal arm muscles, suggesting different excitability thresholds between muscles. In a separate protocol, responses were compared between anode configurations (anterior neck, shoulders, iliac crests, and back), with one selected cathode configuration. The level of discomfort was also assessed. Largest muscle responses were elicited with the anode configuration over the anterior neck, whereas there were no differences in the discomfort. Our results therefore inform methodological considerations for electrode configuration to help optimize recruitment of Ia afferents during cervical tSCS.NEW & NOTEWORTHY We examined selectivity and excitability of motor activation in multiple upper-limb muscles during cervical transcutaneous spinal cord stimulation with different cathode and anode configurations. Hand muscles were more activated when the cathode was configured over the T1 vertebra compared with C6 and C7 locations. Higher stimulation intensities were required to activate distal hand muscles than proximal arm muscles. Finally, configuration of anode over anterior neck elicited larger responses compared with other configurations.
Collapse
Affiliation(s)
- Roberto M de Freitas
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| | - Atsushi Sasaki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan.,Japan Society for the Promotion of Science, Chiyoda, Japan
| | - Dimitry G Sayenko
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
| | - Yohei Masugi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan.,Institute of Sports Medicine and Science, Tokyo International University, Kawagoe, Japan
| | - Taishin Nomura
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| | - Kimitaka Nakazawa
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
| | - Matija Milosevic
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| |
Collapse
|
20
|
Mohammad Mahdi Alavi S, Goetz SM, Saif M. Input-output slope curve estimation in neural stimulation based on optimal sampling principles . J Neural Eng 2021; 18:10.1088/1741-2552/abffe5. [PMID: 33975287 PMCID: PMC8384062 DOI: 10.1088/1741-2552/abffe5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/11/2021] [Indexed: 11/11/2022]
Abstract
This paper discusses some of the practical limitations and issues, which exist for the input-output (IO) slope curve estimation (SCE) in neural, brain and spinal, stimulation techniques. The drawbacks of the SCE techniques by using existing uniform sampling and Fisher-information-based optimal IO curve estimation (FO-IOCE) methods are elaborated. A novel IO SCE technique is proposed with a modified sampling strategy and stopping rule which improve the SCE performance compared to these methods. The effectiveness of the proposed IO SCE is tested on 1000 simulation runs in transcranial magnetic stimulation (TMS), with a realistic model of motor evoked potentials. The results show that the proposed IO SCE method successfully satisfies the stopping rule, before reaching the maximum number of TMS pulses in 79.5% of runs, while the estimation based on the uniform sampling technique never converges and satisfies the stopping rule. At the time of successful termination, the proposed IO SCE method decreases the 95th percentile (mean value in the parentheses) of the absolute relative estimation errors (AREs) of the slope curve parameters up to 7.45% (2.2%), with only 18 additional pulses on average compared to that of the FO-IOCE technique. It also decreases the 95th percentile (mean value in the parentheses) of the AREs of the IO slope curve parameters up to 59.33% (16.71%), compared to that of the uniform sampling method. The proposed IO SCE also identifies the peak slope with higher accuracy, with the 95th percentile (mean value in the parentheses) of AREs reduced by up to 9.96% (2.01%) compared to that of the FO-IOCE method, and by up to 46.29% (13.13%) compared to that of the uniform sampling method.
Collapse
Affiliation(s)
- Seyed Mohammad Mahdi Alavi
- Department of Applied Computing and Engineering, School of Technologies, Cardiff Metropolitan University, Llandaff Campus, Western Avenue, Cardiff CF5 2YB, United Kingdom
| | - Stefan M Goetz
- Departments of Psychiatry and Behavioral Sciences, Electrical and Computer Engineering, and Neurosurgery as well as the Duke Brain Initiative, Duke University, Durham, NC 27708, United States of America
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
| | - Mehrdad Saif
- Department of Electrical Engineering, University of Windsor, Windsor, ON N9B 3P4, Canada
| |
Collapse
|
21
|
Pulverenti TS, Zaaya M, Grabowski M, Grabowski E, Islam MA, Li J, Murray LM, Knikou M. Neurophysiological Changes After Paired Brain and Spinal Cord Stimulation Coupled With Locomotor Training in Human Spinal Cord Injury. Front Neurol 2021; 12:627975. [PMID: 34040572 PMCID: PMC8141587 DOI: 10.3389/fneur.2021.627975] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/01/2021] [Indexed: 11/13/2022] Open
Abstract
Neurophysiological changes that involve activity-dependent neuroplasticity mechanisms via repeated stimulation and locomotor training are not commonly employed in research even though combination of interventions is a common clinical practice. In this randomized clinical trial, we established neurophysiological changes when transcranial magnetic stimulation (TMS) of the motor cortex was paired with transcutaneous thoracolumbar spinal (transspinal) stimulation in human spinal cord injury (SCI) delivered during locomotor training. We hypothesized that TMS delivered before transspinal (TMS-transspinal) stimulation promotes functional reorganization of spinal networks during stepping. In this protocol, TMS-induced corticospinal volleys arrive at the spinal cord at a sufficient time to interact with transspinal stimulation induced depolarization of alpha motoneurons over multiple spinal segments. We further hypothesized that TMS delivered after transspinal (transspinal-TMS) stimulation induces less pronounced effects. In this protocol, transspinal stimulation is delivered at time that allows transspinal stimulation induced action potentials to arrive at the motor cortex and affect descending motor volleys at the site of their origin. Fourteen individuals with motor incomplete and complete SCI participated in at least 25 sessions. Both stimulation protocols were delivered during the stance phase of the less impaired leg. Each training session consisted of 240 paired stimuli delivered over 10-min blocks. In transspinal-TMS, the left soleus H-reflex increased during the stance-phase and the right soleus H-reflex decreased at mid-swing. In TMS-transspinal no significant changes were found. When soleus H-reflexes were grouped based on the TMS-targeted limb, transspinal-TMS and locomotor training promoted H-reflex depression at swing phase, while TMS-transspinal and locomotor training resulted in facilitation of the soleus H-reflex at stance phase of the step cycle. Furthermore, both transspinal-TMS and TMS-transspinal paired-associative stimulation (PAS) and locomotor training promoted a more physiological modulation of motor activity and thus depolarization of motoneurons during assisted stepping. Our findings support that targeted non-invasive stimulation of corticospinal and spinal neuronal pathways coupled with locomotor training produce neurophysiological changes beneficial to stepping in humans with varying deficits of sensorimotor function after SCI.
Collapse
Affiliation(s)
- Timothy S Pulverenti
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Morad Zaaya
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Monika Grabowski
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Ewelina Grabowski
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Md Anamul Islam
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Jeffrey Li
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Lynda M Murray
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States
| | - Maria Knikou
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, New York, NY, United States.,Ph.D. Program in Biology and Collaborative Neuroscience Program, Graduate Center of the City University of New York and College of Staten Island, New York, NY, United States
| |
Collapse
|
22
|
Characterization of Motor-Evoked Responses Obtained with Transcutaneous Electrical Spinal Stimulation from the Lower-Limb Muscles after Stroke. Brain Sci 2021; 11:brainsci11030289. [PMID: 33652677 PMCID: PMC7996860 DOI: 10.3390/brainsci11030289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/06/2021] [Accepted: 02/22/2021] [Indexed: 11/17/2022] Open
Abstract
An increasing number of studies suggests that a novel neuromodulation technique targeting the spinal circuitry enhances gait rehabilitation, but research on its application to stroke survivors is limited. Therefore, we investigated the characteristics of spinal motor-evoked responses (sMERs) from lower-limb muscles obtained by transcutaneous spinal cord stimulation (tSCS) after stroke compared to age-matched and younger controls without stroke. Thirty participants (ten stroke survivors, ten age-matched controls, and ten younger controls) completed the study. By using tSCS applied between the L1 and L2 vertebral levels, we compared sMER characteristics (resting motor threshold (RMT), slope of the recruitment curve, and latency) of the tibialis anterior (TA) and medial gastrocnemius (MG) muscles among groups. A single pulse of stimulation was delivered in 5 mA increments, increasing from 5 mA to 250 mA or until the subjects reached their maximum tolerance. The stroke group had an increased RMT (27–51%) compared to both age-matched (TA: p = 0.032; MG: p = 0.005) and younger controls (TA: p < 0.001; MG: p < 0.001). For the TA muscle, the paretic side demonstrated a 13% increased latency compared to the non-paretic side in the stroke group (p = 0.010). Age-matched controls also exhibited an increased RMT compared to younger controls (TA: p = 0.002; MG: p = 0.007), suggesting that altered sMER characteristics present in stroke survivors may result from both stroke and normal aging. This observation may provide implications for altered spinal motor output after stroke and demonstrates the feasibility of using sMER characteristics as an assessment after stroke.
Collapse
|
23
|
Islam MA, Pulverenti TS, Knikou M. Neuronal Actions of Transspinal Stimulation on Locomotor Networks and Reflex Excitability During Walking in Humans With and Without Spinal Cord Injury. Front Hum Neurosci 2021; 15:620414. [PMID: 33679347 PMCID: PMC7930001 DOI: 10.3389/fnhum.2021.620414] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/25/2021] [Indexed: 12/03/2022] Open
Abstract
This study investigated the neuromodulatory effects of transspinal stimulation on soleus H-reflex excitability and electromyographic (EMG) activity during stepping in humans with and without spinal cord injury (SCI). Thirteen able-bodied adults and 5 individuals with SCI participated in the study. EMG activity from both legs was determined for steps without, during, and after a single-pulse or pulse train transspinal stimulation delivered during stepping randomly at different phases of the step cycle. The soleus H-reflex was recorded in both subject groups under control conditions and following single-pulse transspinal stimulation at an individualized exactly similar positive and negative conditioning-test interval. The EMG activity was decreased in both subject groups at the steps during transspinal stimulation, while intralimb and interlimb coordination were altered only in SCI subjects. At the steps immediately after transspinal stimulation, the physiological phase-dependent EMG modulation pattern remained unaffected in able-bodied subjects. The conditioned soleus H-reflex was depressed throughout the step cycle in both subject groups. Transspinal stimulation modulated depolarization of motoneurons over multiple segments, limb coordination, and soleus H-reflex excitability during assisted stepping. The soleus H-reflex depression may be the result of complex spinal inhibitory interneuronal circuits activated by transspinal stimulation and collision between orthodromic and antidromic volleys in the peripheral mixed nerve. The soleus H-reflex depression by transspinal stimulation suggests a potential application for normalization of spinal reflex excitability after SCI.
Collapse
Affiliation(s)
- Md. Anamul Islam
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY, United States
| | - Timothy S. Pulverenti
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY, United States
| | - Maria Knikou
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, NY, 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, NY, United States
| |
Collapse
|
24
|
McHugh LV, Miller AA, Leech KA, Salorio C, Martin RH. Feasibility and utility of transcutaneous spinal cord stimulation combined with walking-based therapy for people with motor incomplete spinal cord injury. Spinal Cord Ser Cases 2020; 6:104. [PMID: 33239606 PMCID: PMC7688947 DOI: 10.1038/s41394-020-00359-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/03/2022] Open
Abstract
STUDY DESIGN Prospective case series. OBJECTIVES To evaluate the feasibility and preliminary efficacy of combining transcutaneous spinal cord stimulation (TSCS) with walking-based physical therapy. SETTING Hospital-based outpatient center in Maryland, United States. METHODS Ten individuals with chronic (>1 year) motor incomplete spinal cord injury (iSCI) completed 23 sessions of 2-h therapy over 8 weeks. TSCS was delivered for the first 30 min of each session using a clinically available device with adjustable current. To assess feasibility of the intervention, we tracked pain, adverse events, and participant retention. Preliminary efficacy was assessed by evaluating changes in walking speed, endurance, and quality following the intervention with select functional outcome measures (10-m walk test (10MWT), 6-min walk test (6MWT), timed up and go, and walking index for spinal cord injury II). RESULTS We found that the combined intervention was feasible in an outpatient clinical setting. Participants tolerated the TSCS well, with no reports of significant adverse events or other issues (e.g., skin irritation or pain that disrupted training). None of the participants elected to discontinue the study. Participants also showed significant improvements in each measure of walking function following the intervention. Changes in walking speed, as measured by the 10MWT (0.56 ± 0.29 m/s to 0.72 ± 0.36 m/s), exceeded the minimal clinically important difference for individuals with iSCI. Changes in walking quality and endurance, as measured by the 6MWT (149.88 ± 99.87 m to 194.53 ± 106.56 m), exceeded the minimal detectable change for individuals with iSCI. CONCLUSIONS These results indicate that TSCS is clinically feasible and may be useful as an adjunct to walking-based therapy for adults with iSCI.
Collapse
Affiliation(s)
- Liza V McHugh
- International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, MD, 21205, USA
| | - Ashley A Miller
- International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, MD, 21205, USA
| | - Kristan A Leech
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, 90007, USA
| | - Cynthia Salorio
- International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, MD, 21205, USA
- Department of Physical Medicine and Rehabilitation, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Rebecca H Martin
- International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, MD, 21205, USA.
- Department of Physical Medicine and Rehabilitation, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| |
Collapse
|
25
|
Wu YK, Levine JM, Wecht JR, Maher MT, LiMonta JM, Saeed S, Santiago TM, Bailey E, Kastuar S, Guber KS, Yung L, Weir JP, Carmel JB, Harel NY. Posteroanterior cervical transcutaneous spinal stimulation targets ventral and dorsal nerve roots. Clin Neurophysiol 2019; 131:451-460. [PMID: 31887616 DOI: 10.1016/j.clinph.2019.11.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/24/2019] [Accepted: 11/17/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVE We aim to non-invasively facilitate activation of spared neural circuits after cervical spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). We developed and tested a novel configuration for cervical transcutaneous spinal stimulation (cTSS). METHODS cTSS was delivered via electrodes placed over the midline at ~T2-T4 levels posteriorly and ~C4-C5 levels anteriorly. Electromyographic responses were measured in arm and hand muscles across a range of stimulus intensities. Double-pulse experiments were performed to assess homosynaptic post-activation depression (PAD). Safety was closely monitored. RESULTS More than 170 cTSS sessions were conducted without major safety or tolerability issues. A cathode-posterior, 2 ms biphasic waveform provided optimal stimulation characteristics. Bilateral upper extremity muscle responses were easily obtained in subjects with SCI and ALS. Resting motor threshold at the abductor pollicis brevis muscle ranged from 5.5 to 51.0 mA. As stimulus intensity increased, response latencies to all muscles decreased. PAD was incomplete at lower stimulus intensities, and decreased at higher stimulus intensities. CONCLUSIONS Posteroanterior cTSS has the capability to target motor neurons both trans-synaptically via large-diameter afferents and non-synaptically via efferent motor axons. SIGNIFICANCE Posteroanterior cTSS is well tolerated and easily activates upper extremity muscles in individuals with SCI and ALS.
Collapse
Affiliation(s)
- Yu-Kuang Wu
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA; Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Jonah M Levine
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Jaclyn R Wecht
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Matthew T Maher
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - James M LiMonta
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Sana Saeed
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Tiffany M Santiago
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Eric Bailey
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Shivani Kastuar
- Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Kenneth S Guber
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Lok Yung
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
| | - Joseph P Weir
- University of Kansas, 1301 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Jason B Carmel
- Columbia University, 650 West 168th Street, New York, NY 10032, USA
| | - Noam Y Harel
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA; Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
| |
Collapse
|
26
|
Pulverenti TS, Islam MA, Alsalman O, Murray LM, Harel NY, Knikou M. Transspinal stimulation decreases corticospinal excitability and alters the function of spinal locomotor networks. J Neurophysiol 2019; 122:2331-2343. [PMID: 31577515 DOI: 10.1152/jn.00554.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Locomotion requires the continuous integration of descending motor commands and sensory inputs from the legs by spinal central pattern generator circuits. Modulation of spinal neural circuits by transspinal stimulation is well documented, but how transspinal stimulation affects corticospinal excitability during walking in humans remains elusive. We measured the motor evoked potentials (MEPs) at multiple phases of the step cycle conditioned with transspinal stimulation delivered at sub- and suprathreshold intensities of the spinally mediated transspinal evoked potential (TEP). Transspinal stimulation was delivered before or after transcranial magnetic stimulation during which summation between MEP and TEP responses in the surface EMG was absent or present. Relationships between MEP amplitude and background EMG activity, silent period duration, and phase-dependent EMG amplitude modulation during and after stimulation were also determined. Ankle flexor and extensor MEPs were depressed by suprathreshold transspinal stimulation when descending volleys were timed to interact with transspinal stimulation-induced motoneuron depolarization at the spinal cord. MEP depression coincided with decreased MEP gain, unaltered MEP threshold, and unaltered silent period duration. Locomotor EMG activity of bilateral knee and ankle muscles was significantly depressed during the step at which transspinal stimulation was delivered but fully recovered at the subsequent step. The results support a model in which MEP depression by transspinal stimulation occurs via subcortical or spinal mechanisms. Transspinal stimulation disrupts the locomotor output of flexor and extensor motoneurons initially, but the intact nervous system has the ability to rapidly overcome this pronounced locomotor adaptation. In conclusion, transspinal stimulation directly affects spinal locomotor centers in healthy humans.NEW & NOTEWORTHY Lumbar transspinal stimulation decreases ankle flexor and extensor motor evoked potentials (MEPs) during walking. The MEP depression coincides with decreased MEP gain, unaltered MEP threshold changes, and unaltered silent period duration. These findings indicate that MEP depression is subcortical or spinal in origin. Healthy subjects could rapidly overcome the pronounced depression of muscle activity during the step at which transspinal stimulation was delivered. Thus, transspinal stimulation directly affects the function of spinal locomotor networks in healthy humans.
Collapse
Affiliation(s)
- Timothy S Pulverenti
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York
| | - Md Anamul Islam
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York
| | - Ola Alsalman
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York.,Bronx Veterans Medical Research Foundation at the James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York
| | - Lynda M Murray
- Klab4Recovery Research Laboratory, Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York
| | - Noam Y Harel
- Bronx Veterans Medical Research Foundation at the James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York.,Departments of Neurology and Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Maria Knikou
- Klab4Recovery Research Laboratory, 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, New York, New York
| |
Collapse
|
27
|
Repeated transspinal stimulation decreases soleus H-reflex excitability and restores spinal inhibition in human spinal cord injury. PLoS One 2019; 14:e0223135. [PMID: 31557238 PMCID: PMC6762874 DOI: 10.1371/journal.pone.0223135] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/14/2019] [Indexed: 12/12/2022] Open
Abstract
Transcutaneous spinal cord or transspinal stimulation over the thoracolumbar enlargement, the spinal location of motoneurons innervating leg muscles, modulates neural circuits engaged in the control of movement. The extent to which daily sessions (e.g. repeated) of transspinal stimulation affects soleus H-reflex excitability in individuals with chronic spinal cord injury (SCI) remains largely unknown. In this study, we established the effects of repeated cathodal transspinal stimulation on soleus H-reflex excitability and spinal inhibition in individuals with and without chronic SCI. Ten SCI and 10 healthy control subjects received monophasic transspinal stimuli of 1-ms duration at 0.2 Hz at subthreshold and suprathreshold intensities of the right soleus transspinal evoked potential (TEP). SCI subjects received an average of 16 stimulation sessions, while healthy control subjects received an average of 10 stimulation sessions. Before and one or two days post intervention, we used the soleus H reflex to assess changes in motoneuron recruitment, homosynaptic depression following single tibial nerve stimuli delivered at 0.1, 0.125, 0.2, 0.33 and 1.0 Hz, and postactivation depression following paired tibial nerve stimuli at the interstimulus intervals of 60, 100, 300, and 500 ms. Soleus H-reflex excitability was decreased in both legs in motor incomplete and complete SCI but not in healthy control subjects. Soleus H-reflex homosynaptic and postactivation depression was present in motor incomplete and complete SCI but was of lesser strength to that observed in healthy control subjects. Repeated transspinal stimulation increased homosynaptic depression in all SCI subjects and remained unaltered in healthy controls. Postactivation depression remained unaltered in all subject groups. Lastly, transspinal stimulation decreased the severity of spasms and ankle clonus. The results indicate decreased reflex hyperexcitability and recovery of spinal inhibitory control in the injured human spinal cord with repeated transspinal stimulation. Transspinal stimulation is a noninvasive neuromodulation method for restoring spinally-mediated afferent reflex actions after SCI in humans.
Collapse
|