1
|
Al Amin R, Ali AS, Saab IM, Abbas RL. Immediate Neurophysiological effect of electrical stimulation via dry needling on H-reflex in post stroke spasticity. Physiother Theory Pract 2024; 40:1412-1420. [PMID: 36847265 DOI: 10.1080/09593985.2023.2182655] [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: 10/26/2022] [Accepted: 02/15/2023] [Indexed: 03/01/2023]
Abstract
BACKGROUND Many non-pharmacological interventions have been proposed for spasticity modulation in spastic stroke subjects. OBJECTIVE To investigate the immediate effect of dry needling (DN), electrical stimulation (ES), and dry needling with intramuscular electrical stimulation (DN+IMES) on H-reflex in post-stroke spasticity. METHODS Spastic subjects with stroke (N = 90) (55-85 years) were evaluated after 1 month of stroke onset using Modified Ashworth Scale (MAS) score ≥1. Subjects were randomly allocated to receive one session of DN - Soleus (N = 30), ES - posterior lateral side of the leg with 100 Hz and 250 μs pulse width (N = 30), or DN+IMES - Soleus (N = 30). MAS, H-reflex, maximum latency, H-amplitude, M-amplitude and H/M ratio, were recorded before and after one session of intervention. Relationships for each variable within group or the difference among groups were calculated by effect size. RESULTS Significant decrease in H/M ratio in Gastrocnemius and Soleus at post-treatment within DN group (P = .024 and P = .029, respectively), large effect size (d = 0.07 and 0.62, respectively); and DN+IMES group (P = .042 and P = .001, respectively), large effect size (d = 0.69 and 0.71, respectively). No significant differences in all variables at pre-treatment and post-treatment was recorded among ES, DN, and DN+IMES groups. Significant decrease in MAS was recorded at post-treatment compared to pre-treatment within ES group (P = .002), DN group (P = .0001), and DN+IMES group (P = .0001), but not significant (P > .05) among three groups at pre-treatment (P = .194) and post-treatment (P = .485). CONCLUSIONS Single session of DN, ES, and the DN+IMES can significantly modulate post-stroke spasticity by possible bottom-up regulation mechanisms.
Collapse
Affiliation(s)
- Ranim Al Amin
- Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| | - Ahmed S Ali
- Department of Physical Therapy for Neurology, Faculty of Physical Therapy, Cairo University, Egypt
| | - Ibtissam M Saab
- Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| | - Rami L Abbas
- Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| |
Collapse
|
2
|
Song W, Jayaprakash N, Saleknezhad N, Puleo C, Al-Abed Y, Martin JH, Zanos S. Transspinal Focused Ultrasound Suppresses Spinal Reflexes in Healthy Rats. Neuromodulation 2024; 27:614-624. [PMID: 37530695 DOI: 10.1016/j.neurom.2023.04.476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 04/26/2023] [Accepted: 04/29/2023] [Indexed: 08/03/2023]
Abstract
OBJECTIVES Low-intensity, focused ultrasound (FUS) is an emerging noninvasive neuromodulation approach, with improved spatial and temporal resolution and penetration depth compared to other noninvasive electrical stimulation strategies. FUS has been used to modulate circuits in the brain and the peripheral nervous system, however, its potential to modulate spinal circuits is unclear. In this study, we assessed the effect of trans-spinal FUS (tsFUS) on spinal reflexes in healthy rats. MATERIALS AND METHODS tsFUS targeting different spinal segments was delivered for 1 minute, under anesthesia. Monosynaptic H-reflex of the sciatic nerve, polysynaptic flexor reflex of the sural nerve, and withdrawal reflex tested with a hot plate were measured before, during, and after tsFUS. RESULTS tsFUS reversibly suppresses the H-reflex in a spinal segment-, acoustic pressure- and pulse-repetition frequency (PRF)-dependent manner. tsFUS with high PRF augments the degree of homosynaptic depression of the H-reflex observed with paired stimuli. It suppresses the windup of components of the flexor reflex associated with slower, C-afferent, but not faster, A- afferent fibers. Finally, it increases the latency of the withdrawal reflex. tsFUS does not elicit neuronal loss in the spinal cord. CONCLUSIONS Our study provides evidence that tsFUS reversibly suppresses spinal reflexes and suggests that tsFUS could be a safe and effective strategy for spinal cord neuromodulation in disorders associated with hyperreflexia, including spasticity after spinal cord injury and painful syndromes.
Collapse
Affiliation(s)
- Weiguo Song
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Naveen Jayaprakash
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Nafiseh Saleknezhad
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Chris Puleo
- General Electric Research, Niskayuna, NY, USA
| | - Yousef Al-Abed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - John H Martin
- Department of Molecular, Cellular, and Biomedical Sciences, Center for Discovery and Innovation, City University of New York School of Medicine, New York, NY, USA
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA; Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY; Elmezzi Graduate School of Molecular Medicine, Manhasset, NY.
| |
Collapse
|
3
|
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
|
4
|
Dong S, Liu Y, Liu Z, Shen P, Sun H, Zhang P, Fong DTP, Song Q. Can Arthrogenic Muscle Inhibition Exist in Peroneal Muscles Among People with Chronic Ankle Instability? A Cross-sectional Study. SPORTS MEDICINE - OPEN 2024; 10:35. [PMID: 38598018 PMCID: PMC11006644 DOI: 10.1186/s40798-024-00710-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 03/27/2024] [Indexed: 04/11/2024]
Abstract
BACKGROUND Ankle sprains lead to an unexplained reduction of ankle eversion strength, and arthrogenic muscle inhibition (AMI) in peroneal muscles is considered one of the underlying causes. This study aimed to observe the presence of AMI in peroneal muscles among people with chronic ankle instability (CAI). METHODS Sixty-three people with CAI and another sixty-three without CAI conducted maximal voluntary isometric contraction (MVIC) and superimposed burst (SIB) tests during ankle eversion, then fifteen people with CAI and fifteen without CAI were randomly invited to repeat the same tests to calculate the test-retest reliability. Electrical stimulation was applied to the peroneal muscles while the participants were performing MVIC, and the central activation ratio (CAR) was obtained by dividing MVIC torque by the sum of MVIC and SIB torques, representing the degree of AMI. RESULTS The intra-class correlation coefficients were 0.77 (0.45-0.92) and 0.92 (0.79-0.97) for the affected and unaffected limbs among people with CAI, and 0.97 (0.91-0.99) and 0.93 (0.82-0.97) for the controlled affected and unaffected limbs among people without CAI; Significant group × limb interaction was detected in the peroneal CAR (p = 0.008). The CARs were lower among people with CAI in the affected and unaffected limbs, compared with those without CAI (affected limb = 82.54 ± 9.46%, controlled affected limb = 94.64 ± 6.37%, p < 0.001; unaffected limb = 89.21 ± 8.04%, controlled unaffected limb = 94.93 ± 6.01%, p = 0.016). The CARs in the affected limbs were lower than those in the unaffected limbs among people with CAI (p = 0.023). No differences between limbs were found for CAR in the people without CAI (p = 0.10). CONCLUSIONS Bilateral AMI of peroneal muscles is observed among people with CAI. Their affected limbs have higher levels of AMI than the unaffected limbs.
Collapse
Affiliation(s)
- Shiyu Dong
- College of Sports and Health, Shandong Sport University, Jinan, 250102, Shandong, China
| | - Yanhao Liu
- College of Sports and Health, Shandong Sport University, Jinan, 250102, Shandong, China
| | - Ziyin Liu
- College of Sports and Health, Shandong Sport University, Jinan, 250102, Shandong, China
| | - Peixin Shen
- College of Sports and Health, Shandong Sport University, Jinan, 250102, Shandong, China
| | - Hao Sun
- National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Ping Zhang
- National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Daniel T P Fong
- National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Qipeng Song
- College of Sports and Health, Shandong Sport University, Jinan, 250102, Shandong, China.
| |
Collapse
|
5
|
Crouzier M, Avrillon S, Hug F, Cattagni T. Horizontal foot orientation affects the distribution of neural drive between gastrocnemii during plantarflexion, without changing neural excitability. J Appl Physiol (1985) 2024; 136:786-798. [PMID: 38205551 DOI: 10.1152/japplphysiol.00536.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
The distribution of activation among muscles from the same anatomical group can be affected by the mechanical constraints of the task, such as limb orientation. For example, the distribution of activation between the gastrocnemius medialis (GM) and lateralis (GL) muscles during submaximal plantarflexion depends on the orientation of the foot in the horizontal plane. The neural mechanisms behind these modulations are not known. The overall aim of this study was to determine whether the excitability of the two gastrocnemius muscles is differentially affected by changes in foot orientation. Nineteen males performed isometric plantarflexions with their foot internally (toes-in) or externally (toes-out) rotated. GM and GL motor unit discharge characteristics were estimated from high-density surface electromyography to estimate neural drive. GM and GL corticospinal excitability and intracortical activity were assessed using transcranial magnetic stimulation through motor-evoked potentials. The efficacy of synaptic transmission between Ia-afferent fibers and α-motoneurons of the GM and GL was evaluated through the Hoffmann reflex. We observed a differential change in neural drive between GM (toes-out > toes-in) and GL (toes-out < toes-in). However, there was no foot orientation-related modulation in corticospinal excitability of the GM or GL, either at the cortical level or through modulation of the efficacy of Ia-α-motoneuron transmission. These results demonstrate that change in the motor pathway excitability is not the mechanism controlling the different distribution of neural drive between GM and GL with foot orientation.NEW & NOTEWORTHY Horizontal foot orientation affects the distribution of neural drive between the gastrocnemii during plantarflexion. There is no foot orientation-related modulation in the corticospinal excitability of the gastrocnemii, either at the cortical level or through modulation of the efficacy of Ia-α-motoneuron transmission. Change in motor pathway excitability is not the mechanism controlling the different distribution of neural drive between gastrocnemius medialis and lateralis with foot orientation.
Collapse
Affiliation(s)
- Marion Crouzier
- Nantes University, Movement - Interactions - Performance, MIP, UR-4334, Nantes, France
| | - Simon Avrillon
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - François Hug
- Université Côte d'Azur, LAMHESS, Nice, France
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Thomas Cattagni
- Nantes University, Movement - Interactions - Performance, MIP, UR-4334, Nantes, France
| |
Collapse
|
6
|
Castro J, Oliveira Santos M, Swash M, de Carvalho M. Segmental motor neuron dysfunction in amyotrophic lateral sclerosis: Insights from H reflex paradigms. Muscle Nerve 2024; 69:303-312. [PMID: 38220221 DOI: 10.1002/mus.28035] [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: 12/25/2023] [Accepted: 12/29/2023] [Indexed: 01/16/2024]
Abstract
INTRODUCTION/AIMS In amyotrophic lateral sclerosis (ALS), the role of spinal interneurons in ALS is underrecognized. We aimed to investigate pre- and post-synaptic modulation of spinal motor neuron excitability by studying the H reflex, to understand spinal interneuron function in ALS. METHODS We evaluated the soleus H reflex, and three different modulation paradigms, to study segmental spinal inhibitory mechanisms. Homonymous recurrent inhibition (H'RI ) was assessed using the paired H reflex technique. Presynaptic inhibition of Ia afferents (H'Pre ) was evaluated using D1 inhibition after stimulation of the common peroneal nerve. We also studied inhibition of the H reflex after cutaneous stimulation of the sural nerve (H'Pos ). RESULTS Fifteen ALS patients (median age 57.0 years), with minimal signs of lower motor neuron involvement and good functional status, and a control group of 10 healthy people (median age 57.0 years) were studied. ALS patients showed reduced inhibition, compared to controls, in all paradigms (H'RI 0.35 vs. 0.11, p = .036; H'Pre 1.0 vs. 5.0, p = .001; H'Pos 0.0 vs. 2.5, p = .031). The clinical UMN score was a significant predictor of the amount of recurrent and presynaptic inhibition. DISCUSSION Spinal inhibitory mechanisms are impaired in ALS. We argue that hyperreflexia could be associated with dysfunction of spinal inhibitory interneurons. In this case, an interneuronopathy could be deemed a major feature of ALS.
Collapse
Affiliation(s)
- José Castro
- Faculdade de Medicina, Instituto de Fisiologia, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
- Department of Neurosciences and Mental Health, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| | - Miguel Oliveira Santos
- Faculdade de Medicina, Instituto de Fisiologia, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
- Department of Neurosciences and Mental Health, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| | - Michael Swash
- Faculdade de Medicina, Instituto de Fisiologia, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
- Departments of Neurology and Neuroscience, Barts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Mamede de Carvalho
- Faculdade de Medicina, Instituto de Fisiologia, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
- Department of Neurosciences and Mental Health, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| |
Collapse
|
7
|
Omofuma I, Carrera R, King-Ori J, Agrawal SK. The effect of transcutaneous spinal cord stimulation on the balance and neurophysiological characteristics of young healthy adults. WEARABLE TECHNOLOGIES 2024; 5:e3. [PMID: 38486863 PMCID: PMC10936317 DOI: 10.1017/wtc.2023.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 09/01/2023] [Accepted: 10/31/2023] [Indexed: 03/17/2024]
Abstract
Transcutaneous spinal cord stimulation (TSCS) is gaining popularity as a noninvasive alternative to epidural stimulation. However, there is still much to learn about its effects and utility in assisting recovery of motor control. In this study, we applied TSCS to healthy subjects concurrently performing a functional training task to study its effects during a training intervention. We first carried out neurophysiological tests to characterize the H-reflex, H-reflex recovery, and posterior root muscle reflex thresholds, and then conducted balance tests, first without TSCS and then with TSCS. Balance tests included trunk perturbations in forward, backward, left, and right directions, and subjects' balance was characterized by their response to force perturbations. A balance training task involved the subjects playing a catch-and-throw game in virtual reality (VR) while receiving trunk perturbations and TSCS. Balance tests with and without TSCS were conducted after the VR training to measure subjects' post-training balance characteristics and then neurophysiological tests were carried out again. Statistical comparisons using t-tests between the balance and neurophysiological data collected before and after the VR training intervention found that the immediate effect of TSCS was to increase muscle activity during forward perturbations and to reduce balance performance in that direction. Muscle activity decreased after training and even more once TSCS was turned off. We thus observed an interaction of effects where TSCS increased muscle activity while the physical training decreased it.
Collapse
Affiliation(s)
- Isirame Omofuma
- Mechanical Engineering Department, Columbia University, New York, NY, USA
| | - Robert Carrera
- Mechanical Engineering Department, Columbia University, New York, NY, USA
| | | | - Sunil K Agrawal
- Mechanical Engineering Department, Columbia University, New York, NY, USA
| |
Collapse
|
8
|
Robb KA, Green LA, Perry SD. The use of textured foot orthoses to facilitate cutaneous afferent input during walking. Neurosci Lett 2024; 818:137566. [PMID: 37996050 DOI: 10.1016/j.neulet.2023.137566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/12/2023] [Accepted: 11/20/2023] [Indexed: 11/25/2023]
Affiliation(s)
- Kelly A Robb
- Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON, CANADA N2L 3C5, Canada.
| | - Lara A Green
- Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON, CANADA N2L 3C5, Canada.
| | - Stephen D Perry
- Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON, CANADA N2L 3C5, Canada.
| |
Collapse
|
9
|
Thorstensen JR, Henderson TT, Kavanagh JJ. Serotonergic and noradrenergic contributions to motor cortical and spinal motoneuronal excitability in humans. Neuropharmacology 2024; 242:109761. [PMID: 37838337 DOI: 10.1016/j.neuropharm.2023.109761] [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: 07/04/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Animal models indicate that motor behaviour is shaped by monoamine neuromodulators released diffusely throughout the brain and spinal cord. As an alternative to conducting a single study to explore the effects of neuromodulators on the human motor system, we have identified and collated human experiments investigating motor effects of well-characterised drugs that act on serotonergic and noradrenergic networks. In doing so, we present strong neuropharmacology evidence that human motor pathways are affected by neuromodulators across both healthy and clinical populations, insight that cannot be determined from a single reductionist experiment. We have focused our review on the effects that monoaminergic drugs have on muscle responses to non-invasive stimulation of the motor cortex and peripheral nerves, and other closely related tests of motoneuron excitability, and discuss how these measurement techniques elucidate the effects of neuromodulators at motor cortical and spinal motoneuronal levels. Although there is some heterogeneity in study methods, we find drugs acting to enhance extracellular concentrations of serotonin tend to reduce the excitability of the human motor cortex, and enhanced extracellular concentrations of noradrenaline increases motor cortical excitability by enhancing intracortical facilitation and reducing inhibition. Both monoamines tend to enhance the excitability of spinal motoneurons. Overall, this review details the importance of neuromodulators for the output of human motor pathways and suggests that commonly prescribed monoaminergic drugs target the motor system in addition to their typical psychiatric/neurological indications.
Collapse
Affiliation(s)
- Jacob R Thorstensen
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.
| | - Tyler T Henderson
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| |
Collapse
|
10
|
Nakamura J, Nishimae T, Uchisawa H, Okada Y, Shiozaki T, Tanaka H, Ueta K, Fujita D, Tsujimoto N, Ikuno K, Shomoto K. Effects of postural-control training with different sensory reweightings in a patient with body lateropulsion: a single-subject design study. Physiother Theory Pract 2023:1-11. [PMID: 37916486 DOI: 10.1080/09593985.2023.2274943] [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: 04/06/2023] [Accepted: 10/18/2023] [Indexed: 11/03/2023]
Abstract
INTRODUCTION Body lateropulsion (BL) is an active lateral tilt of the body during standing or walking that is thought to be affected by a lesion of the vestibulospinal tract (VST) and the subjective visual vertical (SVV) tilt. Interventions for BL have not been established. OBJECTIVE We examined the effects of postural-control training with different sensory reweighting on standing postural control in a patient with BL. METHODS The patient had BL to the left when standing or walking due to a left-side medullary and cerebellar infarct. This study was a single-subject A-B design with follow-up: Phase A was postural-control training with visual feedback; phase B provided reweighting plantar somatosensory information. Postural control, VST excitability, and SVV were measured. RESULTS At baseline and phase A, the patient could not stand with eyes-closed on a rubber mat, but became able to stand in phase B. The mediolateral center of pressure (COP) position did not change significantly, but the COP velocity decreased significantly during phase B and the follow-up on the firm surface. VST excitability was lower on the BL versus the non-BL side, and the SVV deviated to the right throughout the study. CONCLUSION Postural-control training with reweighting somatosensory information might improve postural control in a patient with BL.
Collapse
Affiliation(s)
- Junji Nakamura
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
- Graduate School of Health Sciences, Kio University, Nara, Japan
| | - Takuma Nishimae
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Hidekazu Uchisawa
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Yohei Okada
- Graduate School of Health Sciences, Kio University, Nara, Japan
- Neurorehabilitation Research Center of Kio University, Nara, Japan
| | - Tomoyuki Shiozaki
- Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, Kashihara-City, Nara, Japan
| | - Hiroaki Tanaka
- KMU Day-care Center Hirakata, Kansai Medical University Hospital, Hirakata-City, Osaka, Japan
- Department of Physical Medicine and Rehabilitation, Kansai Medical University, Osaka, Japan
| | - Kozo Ueta
- Graduate School of Health Sciences, Kio University, Nara, Japan
- Department of Rehabilitation Medicine, Shiga Hospital, Otsu-Shi, Shiga, Japan
| | - Daiki Fujita
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Naohide Tsujimoto
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Koki Ikuno
- Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan
- Graduate School of Health Sciences, Kio University, Nara, Japan
| | - Koji Shomoto
- Graduate School of Health Sciences, Kio University, Nara, Japan
| |
Collapse
|
11
|
Li S, Triolo RJ, Charkhkar H. Neural sensory stimulation does not interfere with the H-reflex in individuals with lower limb amputation. Front Neurosci 2023; 17:1276308. [PMID: 37817801 PMCID: PMC10560717 DOI: 10.3389/fnins.2023.1276308] [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: 08/11/2023] [Accepted: 09/12/2023] [Indexed: 10/12/2023] Open
Abstract
Introduction Individuals with lower limb loss experience an increased risk of falls partly due to the lack of sensory feedback from their missing foot. It is possible to restore plantar sensation perceived as originating from the missing foot by directly interfacing with the peripheral nerves remaining in the residual limb, which in turn has shown promise in improving gait and balance. However, it is yet unclear how these electrically elicited plantar sensation are integrated into the body's natural sensorimotor control reflexes. Historically, the H-reflex has been used as a model for investigating sensorimotor control. Within the spinal cord, an array of inputs, including plantar cutaneous sensation, are integrated to produce inhibitory and excitatory effects on the H-reflex. Methods In this study, we characterized the interplay between electrically elicited plantar sensations and this intrinsic reflex mechanism. Participants adopted postures mimicking specific phases of the gait cycle. During each posture, we electrically elicited plantar sensation, and subsequently the H-reflex was evoked both in the presence and absence of these sensations. Results Our findings indicated that electrically elicited plantar sensations did not significantly alter the H-reflex excitability across any of the adopted postures. Conclusion This suggests that individuals with lower limb loss can directly benefit from electrically elicited plantar sensation during walking without disrupting the existing sensory signaling pathways that modulate reflex responses.
Collapse
Affiliation(s)
- Suzhou Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
| | - Ronald J. Triolo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
| | - Hamid Charkhkar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
| |
Collapse
|
12
|
Anvar SH, Granacher U, Konrad A, Alizadeh S, Culleton R, Edwards C, Goudini R, Behm DG. Corticospinal excitability and reflex modulation in a contralateral non-stretched muscle following unilateral stretching. Eur J Appl Physiol 2023; 123:1837-1850. [PMID: 37072505 DOI: 10.1007/s00421-023-05200-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 04/10/2023] [Indexed: 04/20/2023]
Abstract
PURPOSE Muscle stretching effect on the range of motion (ROM) and force deficit in non-stretched muscle, and the underlying mechanisms, is an ongoing issue. This study aimed to investigate crossover stretching effects and mechanisms on the plantar flexor muscles. METHODS Fourteen recreationally active females (n = 5) and males (n = 9) performed six sets of 45-s static stretching (SS) (15-s recovery) to the point of discomfort of the dominant leg (DL) plantar flexors or control (345-s rest). Participants were tested for a single 5-s pre- and post-test maximal voluntary isometric contraction (MVIC) with each plantar flexor muscle and were tested for DL and non-DL ROM. They were tested pre- and post-test (immediate, 10-s, 30-s) for the Hoffman (H)-reflex and motor-evoked potentials (MEP) from transcranial magnetic stimulation in the contralateral, non-stretched muscle. RESULTS Both the DL and non-DL-MVIC force had large magnitude, significant (↓10.87%, p = 0.027, pƞ2 = 0.4) and non-significant (↓9.53%, p = 0.15, pƞ2 = 0.19) decreases respectively with SS. The SS also significantly improved the DL (6.5%, p < 0.001) and non-DL (5.35%, p = 0.002) ROM. The non-DL MEP/MMax and HMax/MMax ratio did not change significantly. CONCLUSION Prolonged static stretching improved the stretched muscle's ROM. However, the stretched limb's force was negatively affected following the stretching protocol. The ROM improvement and large magnitude force impairment (statistically non-significant) were transferred to the contralateral muscles. The lack of significant changes in spinal and corticospinal excitability confirms that the afferent excitability of the spinal motoneurons and corticospinal excitability may not play a substantial role in non-local muscle's ROM or force output responses.
Collapse
Affiliation(s)
- Saman Hadjizadeh Anvar
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Urs Granacher
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Andreas Konrad
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
- Institute of Human Movement Science, Sport and Health, Graz University, Graz, Austria
| | - Shahab Alizadeh
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Robyn Culleton
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Chris Edwards
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Reza Goudini
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - David G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
| |
Collapse
|
13
|
McKinnon ML, Hill NJ, Carp JS, Dellenbach B, Thompson AK. Methods for automated delineation and assessment of EMG responses evoked by peripheral nerve stimulation in diagnostic and closed-loop therapeutic applications. J Neural Eng 2023; 20:10.1088/1741-2552/ace6fb. [PMID: 37437593 PMCID: PMC10445400 DOI: 10.1088/1741-2552/ace6fb] [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: 03/17/2023] [Accepted: 07/12/2023] [Indexed: 07/14/2023]
Abstract
Objective.Surface electromyography measurements of the Hoffmann (H-) reflex are essential in a wide range of neuroscientific and clinical applications. One promising emerging therapeutic application is H-reflex operant conditioning, whereby a person is trained to modulate the H-reflex, with generalized beneficial effects on sensorimotor function in chronic neuromuscular disorders. Both traditional diagnostic and novel realtime therapeutic applications rely on accurate definitions of the H-reflex and M-wave temporal bounds, which currently depend on expert case-by-case judgment. The current study automates such judgments.Approach.Our novel wavelet-based algorithm automatically determines temporal extent and amplitude of the human soleus H-reflex and M-wave. In each of 20 participants, the algorithm was trained on data from a preliminary 3 or 4 min recruitment-curve measurement. Output was evaluated on parametric fits to subsequent sessions' recruitment curves (92 curves across all participants) and on the conditioning protocol's subsequent baseline trials (∼1200 per participant) performed nearHmax. Results were compared against the original temporal bounds estimated at the time, and against retrospective estimates made by an expert 6 years later.Main results.Automatic bounds agreed well with manual estimates: 95% lay within ±2.5 ms. The resulting H-reflex magnitude estimates showed excellent agreement (97.5% average across participants) between automatic and retrospective bounds regarding which trials would be considered successful for operant conditioning. Recruitment-curve parameters also agreed well between automatic and manual methods: 95% of the automatic estimates of the current required to elicitHmaxfell within±1.4%of the retrospective estimate; for the 'threshold' current that produced an M-wave 10% of maximum, this value was±3.5%.Significance.Such dependable automation of M-wave and H-reflex definition should make both established and emerging H-reflex protocols considerably less vulnerable to inter-personnel variability and human error, increasing translational potential.
Collapse
Affiliation(s)
| | - N. Jeremy Hill
- National Center for Adaptive Neurotechnologies, Stratton VA Medical Center, Albany, NY, USA
- Electrical and Computer Engineering Dept., State University of New York at Albany, NY, USA
| | - Jonathan S. Carp
- National Center for Adaptive Neurotechnologies, Stratton VA Medical Center, Albany, NY, USA
- School of Public Health, State University of New York at Albany, NY, USA
| | | | | |
Collapse
|
14
|
Metz K, Matos IC, Hari K, Bseis O, Afsharipour B, Lin S, Singla R, Fenrich KK, Li Y, Bennett DJ, Gorassini MA. Post-activation depression from primary afferent depolarization (PAD) produces extensor H-reflex suppression following flexor afferent conditioning. J Physiol 2023; 601:1925-1956. [PMID: 36928599 PMCID: PMC11064783 DOI: 10.1113/jp283706] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Suppression of the extensor H-reflex by flexor afferent conditioning is thought to be produced by a long-lasting inhibition of extensor Ia afferent terminals via GABAA receptor-activated primary afferent depolarization (PAD). Given the recent finding that PAD does not produce presynaptic inhibition of Ia afferent terminals, we examined in 28 participants if H-reflex suppression is instead mediated by post-activation depression of the extensor Ia afferents triggered by PAD-evoked spikes and/or by a long-lasting inhibition of the extensor motoneurons. A brief conditioning vibration of the flexor tendon suppressed both the extensor soleus H-reflex and the tonic discharge of soleus motor units out to 150 ms following the vibration, suggesting that part of the H-reflex suppression during this period was mediated by postsynaptic inhibition of the extensor motoneurons. When activating the flexor afferents electrically to produce conditioning, the soleus H-reflex was also suppressed but only when a short-latency reflex was evoked in the soleus muscle by the conditioning input itself. In mice, a similar short-latency reflex was evoked when optogenetic or afferent activation of GABAergic (GAD2+ ) neurons produced a large enough PAD to evoke orthodromic spikes in the test Ia afferents, causing post-activation depression of subsequent monosynaptic EPSPs. The long duration of this post-activation depression and related H-reflex suppression (seconds) was similar to rate-dependent depression that is also due to post-activation depression. We conclude that extensor H-reflex inhibition by brief flexor afferent conditioning is produced by both post-activation depression of extensor Ia afferents and long-lasting inhibition of extensor motoneurons, rather than from PAD inhibiting Ia afferent terminals. KEY POINTS: Suppression of extensor H-reflexes by flexor afferent conditioning was thought to be mediated by GABAA receptor-mediated primary afferent depolarization (PAD) shunting action potentials in the Ia afferent terminal. In line with recent findings that PAD has a facilitatory role in Ia afferent conduction, we show here that when large enough, PAD can evoke orthodromic spikes that travel to the Ia afferent terminal to evoke EPSPs in the motoneuron. These PAD-evoked spikes also produce post-activation depression of Ia afferent terminals and may mediate the short- and long-lasting suppression of extensor H-reflexes in response to flexor afferent conditioning. Our findings highlight that we must re-examine how changes in the activation of GABAergic interneurons and PAD following nervous system injury or disease affects the regulation of Ia afferent transmission to spinal neurons and ultimately motor dysfunction in these disorders.
Collapse
Affiliation(s)
- Krista Metz
- Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Isabel Concha Matos
- Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Krishnapriya Hari
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Omayma Bseis
- Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Babak Afsharipour
- Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Shihao Lin
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Rahul Singla
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Keith K Fenrich
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Yaqing Li
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - David J Bennett
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Monica A Gorassini
- Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| |
Collapse
|
15
|
Melo ASC, Taylor JL, Ferreira R, Cunha B, Ascenção M, Fernandes M, Sousa V, Cruz EB, Vilas-Boas JP, Sousa ASP. Differences in Trapezius Muscle H-Reflex between Asymptomatic Subjects and Symptomatic Shoulder Pain Subjects. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094217. [PMID: 37177422 PMCID: PMC10180810 DOI: 10.3390/s23094217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/12/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023]
Abstract
In chronic shoulder pain, adaptations in the nervous system such as in motoneuron excitability, could contribute to impairments in scapular muscles, perpetuation and recurrence of pain and reduced improvements during rehabilitation. The present cross-sectional study aims to compare trapezius neural excitability between symptomatic and asymptomatic subjects. In 12 participants with chronic shoulder pain (symptomatic group) and 12 without shoulder pain (asymptomatic group), the H reflex was evoked in all trapezius muscle parts, through C3/4 nerve stimulation, and the M-wave through accessory nerve stimulation. The current intensity to evoke the maximum H reflex, the latency and the maximum peak-to-peak amplitude of both the H reflex and M-wave, as well as the ratio between these two variables, were calculated. The percentage of responses was considered. Overall, M-waves were elicited in most participants, while the H reflex was elicited only in 58-75% or in 42-58% of the asymptomatic and symptomatic participants, respectively. A comparison between groups revealed that the symptomatic group presented a smaller maximum H reflex as a percentage of M-wave from upper trapezius and longer maximal H reflex latency from the lower trapezius (p < 0.05). Subjects with chronic shoulder pain present changes in trapezius H reflex parameters, highlighting the need to consider trapezius neuromuscular control in these individuals' rehabilitation.
Collapse
Affiliation(s)
- Ana S C Melo
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Porto Biomechanics Laboratory (LABIOMEP-UP), University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Center for Interdisciplinary Applied Research in Health, School of Health, Setubal Polytechnic Institute, Campus do IPS Estefanilha, 2914-503 Setubal, Portugal
| | - Janet L Taylor
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Perth, WA 6027, Australia
- Neuroscience Research Australia, Sydney, NSW 2031, Australia
| | - Ricardo Ferreira
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Bruno Cunha
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Manuel Ascenção
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Mathieu Fernandes
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Vítor Sousa
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Eduardo B Cruz
- Department of Physiotherapy, Escola Superior de Saúde, Instituto Politécnico de Setúbal, Campus do IPS Estefanilha, 2914-503 Setúbal, Portugal
- Comprehensive Health Research Center (CHRC), Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - J Paulo Vilas-Boas
- Porto Biomechanics Laboratory (LABIOMEP-UP), University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
| | - Andreia S P Sousa
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| |
Collapse
|
16
|
Matsugi A. Cerebellar TMS Induces Motor Responses Mediating Modulation of Spinal Excitability: A Literature Review. Brain Sci 2023; 13:brainsci13040531. [PMID: 37190496 DOI: 10.3390/brainsci13040531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 05/17/2023] Open
Abstract
Since individuals with cerebellar lesions often exhibit hypotonia, the cerebellum may contribute to the regulation of muscle tone and spinal motoneuron pool excitability. Neurophysiological methods using transcranial magnetic stimulation (TMS) of the cerebellum have been recently proposed for testing the role of the cerebellum in spinal excitability. Under specific conditions, single-pulse TMS administered to the cerebellar hemisphere or vermis elicits a long-latency motor response in the upper or lower limb muscles and facilitates the H-reflex of the soleus muscle, indicating increased excitability of the spinal motoneuron pool. This literature review examined the methods and mechanisms by which cerebellar TMS modulates spinal excitability.
Collapse
Affiliation(s)
- Akiyoshi Matsugi
- Faculty of Rehabilitation, Shijonawate Gakuen University, Osaka 574-0011, Japan
| |
Collapse
|
17
|
F-waves induced by motor point stimulation are facilitated during handgrip and motor imagery tasks. Exp Brain Res 2023; 241:527-537. [PMID: 36622384 DOI: 10.1007/s00221-022-06537-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 12/21/2022] [Indexed: 01/10/2023]
Abstract
The F-wave is a motor response elicited via the antidromic firings of motor nerves by the electrical stimulation of peripheral nerves, which reflects the motoneuron pool excitability. However, the F-wave generally has low robustness i.e., low persistence and small amplitude. We recently found that motor point stimulation (MPS), which provides the muscle belly with electrical stimulation, shows different neural responses compared to nerve stimulation, e.g., MPS elicits F-waves more robustly than nerve stimulation. Here, we investigated whether F-waves induced by MPS can identify changes in motoneuron pool excitability during handgrip and motor imagery. Twelve participants participated in the present study. We applied MPS on their soleus muscle and recorded F-waves during eyes-open (EO), eyes-closed (EC), handgrip (HG), and motor imagery (MI) conditions. In the EO and EC conditions, participants relaxed with their eyes open and closed, respectively. In the HG, participants matched the handgrip force level to 30% of the maximum voluntary force with visual feedback. In the MI, they performed kinesthetic MI of plantarflexion at the maximal strength with closed eyes. In the HG and MI, the amplitudes of the F-waves induced by MPS were increased compared with those in the EO and EC, respectively. These results indicate that the motoneuron pool excitability was facilitated during the HG and MI conditions, consistent with findings in previous studies. Our findings suggest that F-waves elicited by MPS can be a good tool in human neurophysiology to assess the motoneuron pool excitability during cognitive and motor tasks.
Collapse
|
18
|
Pfenninger C, Grosboillot N, Digonet G, Lapole T. Effects of prolonged local vibration superimposed to muscle contraction on motoneuronal and cortical excitability. Front Physiol 2023; 14:1106387. [PMID: 36711014 PMCID: PMC9877338 DOI: 10.3389/fphys.2023.1106387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/03/2023] [Indexed: 01/14/2023] Open
Abstract
Introduction: Acute effects of prolonged local vibration (LV) at the central nervous system level have been well investigated demonstrating an altered motoneuronal excitability with a concomitant increase in cortical excitability. While applying LV during isometric voluntary contraction is thought to optimize the effects of LV, this has never been addressed considering the acute changes in central nervous system excitability. Materials and Methods: In the present study, nineteen healthy participants were engaged in four randomized sessions. LV was applied for 30 min to the relaxed flexor carpi radialis muscle (VIBRELAXED) or during wrist flexions (i.e. intermittent contractions at 10% of the maximal voluntary contraction: 15 s ON and 15 s OFF; VIBCONTRACT). A control condition and a condition where participants only performed repeated low-contractions at 10% maximal force (CONTRACT) were also performed. For each condition, motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials (CMEPs) elicited by corticospinal tract electrical stimulation were measured before (PRE) and immediately after prolonged LV (POST) to investigate motoneuronal and corticospinal excitability, respectively. We further calculated the MEP/CMEP ratio as a proxy of cortical excitability. Results: No changes were observed in the control nor CONTRACT condition. At POST, CMEP decreased similarly in VIBRELAXED (-32% ± 42%, p < .001) and VIBCONTRACT (-41% ± 32%, p < .001). MEP/CMEP increased by 110% ± 140% (p = .01) for VIBRELAXED and by 120% ± 208% (p = .02) for VIBCONTRACT without differences between those conditions. Discussion: Our results suggest that LV to the flexor carpi radialis muscle, either relaxed or contracted, acutely decreases motoneuronal excitability and induces some priming of cortical excitability.
Collapse
Affiliation(s)
- Clara Pfenninger
- Laboratoire Interuniversitaire de Biologie de la Motricité, Lyon 1, Université Savoie Mont-Blanc, Université Jean Monnet Saint-Etienne, Saint-Étienne, France
| | - Nathan Grosboillot
- Laboratoire Interuniversitaire de Biologie de la Motricité, Lyon 1, Université Savoie Mont-Blanc, Université Jean Monnet Saint-Etienne, Saint-Étienne, France,HAVAE EA6310, Faculty of Science and Technology, University of Limoges, Limoges, France
| | - Guillaume Digonet
- University Lyon, UCBL-Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Thomas Lapole
- Laboratoire Interuniversitaire de Biologie de la Motricité, Lyon 1, Université Savoie Mont-Blanc, Université Jean Monnet Saint-Etienne, Saint-Étienne, France,*Correspondence: Thomas Lapole,
| |
Collapse
|
19
|
Can motor imagery balance the acute fatigue induced by neuromuscular electrical stimulation? Eur J Appl Physiol 2023; 123:1003-1014. [PMID: 36622447 DOI: 10.1007/s00421-022-05129-5] [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: 07/04/2022] [Accepted: 12/26/2022] [Indexed: 01/10/2023]
Abstract
PURPOSE The combination of motor imagery (MI) and neuromuscular electrical stimulation (NMES) can increase the corticospinal excitability suggesting that such association could be efficient in motor performance improvement. However, differential effect has been reported at spinal level after MI and NMES alone. The purpose of this study was to investigate the acute effect on motor performance and spinal excitability following MI, NMES and combining MI and NMES. METHODS Ten participants were enrolled in three experimental sessions of MI, NMES and MI + NMES targeting plantar flexor muscles. Each session underwent 60 imagined, evoked (20% MVC) or imagined and evoked contractions simultaneously. Before, immediately after and 10 min after each session, maximal M-wave and H-reflex were evoked by electrical nerve stimulation applied at rest and during maximal voluntary contraction (MVC). RESULTS The MVC decreased significantly between PRE-POST (- 12.14 ± 6.12%) and PRE-POST 10 (- 8.1 ± 6.35%) for NMES session, while this decrease was significant only between PRE-POST 10 (- 7.16 ± 11.25%) for the MI + NMES session. No significant modulation of the MVC was observed after MI session. The ratio Hmax/Mmax was reduced immediately after NMES session only. CONCLUSION The combination of MI to NMES seems to delay the onset of neuromuscular fatigue compared to NMES alone. This delay onset of neuromuscular fatigue was associated with specific modulation of the spinal excitability. These results suggested that MI could compensate the neuromuscular fatigue induced acutely by NMES until 10 min after the combination of both modalities.
Collapse
|
20
|
Chen YL, Jiang LJ, Cheng YY, Chen C, Hu J, Zhang AJ, Hua Y, Bai YL. Focal vibration of the plantarflexor and dorsiflexor muscles improves poststroke spasticity: a randomized single-blind controlled trial. Ann Phys Rehabil Med 2022; 66:101670. [PMID: 35940478 DOI: 10.1016/j.rehab.2022.101670] [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: 09/24/2021] [Revised: 01/23/2022] [Accepted: 02/15/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND Post-stroke spasticity is a cause of gait dysfunction and disability. Focal vibration (FV) of agonist-antagonist upper limb muscle pairs reduces flexor spasticity; however, its effects on ankle plantarflexor spasticity are uncertain. OBJECTIVE To assess the effects of focal vibration administered by a trained operator to the ankle plantarflexor and dorsiflexor muscles on post-stroke lower limb spasticity. METHODS A randomized, single-blind controlled trial of 64 participants with stroke and plantarflexor spasticity assigned to 3 groups by centralized, computer-generated randomization (1:1:1): 1) physiotherapy alone (CON), 2) physiotherapy+gastrocnemius vibration (FV_GM) and 3) physiotherapy+tibialis anterior vibration (FV_TA). Physiotherapists and assessors were blinded to group assignment. The experimental groups underwent 15, 20-min vibration sessions at 40 Hz. We performed evaluations at baseline and after the final treatment: Modified Ashworth Scale (MAS), Clonus scale, Functional Ambulation Categories (FAC), Fugl-Meyer Assessment - Lower Extremity (FMA_LE), Modified Barthel Index (MBI), and electromyography and ultrasound elastography. Primary outcome was remission rate (number and proportion of participants) of the MAS. RESULTS MAS remission rate was higher in FV_GM and FV_TA than CON groups (CON vs. FV_GM: p=0.009, odds ratio 0.15 [95% confidence interval 0.03-0.67]; CON vs. FV_TA: p=0.002, 0.12 [0.03-0.51]). Remission rate was higher in the experimental than CON groups for the Clonus scale (CON vs. FV_GM: p<0.001, OR 0.07 [95% CI 0.01-0.31]; CON vs. FV_TA: p=0.006, 0.14 [95% CI 0.03-0.61]). FAC remission rate was higher in the FV_TA than the CON (p=0.009, 0.18 [0.05-0.68]) and FV_GM (p=0.014, 0.27 [0.07-0.99]) groups. Ultrasound variables of the paretic medial gastrocnemius decreased more in FV_GM than CON and FV_TA groups (shear modulus: p=0.006; shear wave velocity: p=0.008). CONCLUSIONS Focal vibration reduced post-stroke spasticity of the plantarflexor muscles. Vibration of the tibialis anterior improved ambulation more than vibration of the gastrocnemius or physiotherapy alone. Gastrocnemius vibration may reduce spasticity by changing muscle stiffness.
Collapse
Affiliation(s)
- Ying-Lun Chen
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, People's Republic of China; Department of Rehabilitation Medicine, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Liu-Jun Jiang
- Department of Rehabilitation Medicine, Huashan North Hospital, Fudan University, Shanghai, People's Republic of China
| | - Yang-Yang Cheng
- Department of Rehabilitation Medicine, Huashan North Hospital, Fudan University, Shanghai, People's Republic of China
| | - Chan Chen
- Department of Rehabilitation Medicine, Huashan North Hospital, Fudan University, Shanghai, People's Republic of China
| | - Jian Hu
- Department of Rehabilitation Medicine, Huashan North Hospital, Fudan University, Shanghai, People's Republic of China
| | - An-Jing Zhang
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Yan Hua
- Department of Rehabilitation Medicine, Huashan North Hospital, Fudan University, Shanghai, People's Republic of China.
| | - Yu-Long Bai
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.
| |
Collapse
|
21
|
Tahayori B, Tahayori B, Mehdizadeh A, Koceja DM. Postural displacement induced by electrical stimulation; A new approach to examine postural recovery. PLoS One 2022; 17:e0273282. [PMID: 35981077 PMCID: PMC9387811 DOI: 10.1371/journal.pone.0273282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/05/2022] [Indexed: 11/18/2022] Open
Abstract
Background Controlling upright posture entails acute adjustments by the neuromuscular system to keep the center of mass (COM) within the limits of a relatively small base of support. Sudden displacement of the COM triggers several strategies and balance recovery mechanisms to prevent excessive COM displacement. New method We have examined and quantified a new approach to induce an internal neuromuscular perturbation in standing posture on 15 healthy individuals to provide an insight into the mechanism of loss of balance (LOB). The method comprises eliciting an H-reflex protocol while subjects are standing which produces a contraction in soleus and gastrocnemius muscles. We have also defined analytical techniques to provide biomarkers of balance control during perturbation. We used M-Max unilaterally or bilaterally and induced a forward or sideway perturbation. The vector analysis and the Equilibrium Point calculations defined here can quantify the amplitude, direction, and evolution of the perturbation. Results Clear patterns of loss of balance due to stimulation was observed. Compared to quiet standing, the density of the EPs substantially increased in the perturbation phase. Leftward stimulation produced significantly higher number of EPs compared to the bilateral stimulation condition which could be due to the fact that the left leg was the nondominant side in all our subjects. Comparison and conclusion In this study we provide a proof-of-concept technique for examining recovery from perturbation. The advantage of this technique is that it provides a safe perturbation, is internally induced at the spinal cord level, and is free from other factors that might complicate the recovery analysis (e.g., locomotion and the integration of the spinal pattern generator and cutaneous pathways in mediating changes). We have shown that the perturbation induced by this method can be quantified as vectors. We have also shown that the density of instantaneous equilibrium points (EPs) could be a good biomarker for defining and examining the perturbation phase. Thus, this protocol and analysis provides a unique individual assessment of recovery which can be used to assess interventions. Finally, given that the maximal motor response is used as the perturbation (e.g., M-max) it is highly reliable and reproducible within an individual patient.
Collapse
Affiliation(s)
- Behdad Tahayori
- Department of Physical Therapy, University of Saint Augustine, Miami FL, United States of America
| | - Bahman Tahayori
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, VIC, Australia
| | - Alireza Mehdizadeh
- Department of Medical Physics, Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- * E-mail:
| | - David M. Koceja
- Department of Kinesiology and Program in Neural Sciences, Indiana University, Bloomington, IN, United States of America
| |
Collapse
|
22
|
Kaneko N, Fok KL, Nakazawa K, Masani K. Motor point stimulation induces more robust F-waves than peripheral nerve stimulation. Eur J Neurosci 2022; 55:1614-1628. [PMID: 35178805 DOI: 10.1111/ejn.15625] [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: 08/20/2021] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/27/2022]
Abstract
The F-wave is a motor response induced by electrical stimulation of peripheral nerves via the antidromic firing of motor nerves, which reflects the motoneuron excitability. To induce F-waves, transcutaneous peripheral nerve stimulation (PNS) is used, which activates nerve branches via transcutaneous electrodes over the nerve branches. An alternative method to activate peripheral nerves, i.e., motor point stimulation (MPS) which delivers electrical stimulation over the muscle belly, has not been used to induce F-waves. In our previous studies, we observed that MPS induced F-wave like responses, i.e., motor responses at the latency of F-waves at a supramaximal stimulation. Here we further investigated the F-wave like responses induced by MPS in comparison to PNS in the soleus muscle. Thirteen individuals participated in this study. We applied MPS and PNS on the participant's left soleus muscle. Using a monopolar double-pulse stimulation, the amplitude of the second H-reflex induced by PNS decreased, while the amplitude of the motor response at the F-wave latency induced by MPS did not decrease. These results suggest that the motor response at the F-wave latency induced by MPS was not an H-reflex but an F-wave. We also found that the F-wave induced by MPS had a greater amplitude, higher persistence, and caused less pain when compared to the F-waves induced using PNS. We conclude that MPS evokes antidromic firing inducing F-waves more consistently compared to PNS.
Collapse
Affiliation(s)
- Naotsugu Kaneko
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,KITE - Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Kai Lon Fok
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,KITE - Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
| | - Kimitaka Nakazawa
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Kei Masani
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,KITE - Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
| |
Collapse
|
23
|
Kudina LP, Andreeva RE. Human motoneuron firing behavior and single motor unit F-wave. J Electromyogr Kinesiol 2022; 63:102641. [DOI: 10.1016/j.jelekin.2022.102641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022] Open
|
24
|
Abstract
When animals walk overground, mechanical stimuli activate various receptors located in muscles, joints, and skin. Afferents from these mechanoreceptors project to neuronal networks controlling locomotion in the spinal cord and brain. The dynamic interactions between the control systems at different levels of the neuraxis ensure that locomotion adjusts to its environment and meets task demands. In this article, we describe and discuss the essential contribution of somatosensory feedback to locomotion. We start with a discussion of how biomechanical properties of the body affect somatosensory feedback. We follow with the different types of mechanoreceptors and somatosensory afferents and their activity during locomotion. We then describe central projections to locomotor networks and the modulation of somatosensory feedback during locomotion and its mechanisms. We then discuss experimental approaches and animal models used to investigate the control of locomotion by somatosensory feedback before providing an overview of the different functional roles of somatosensory feedback for locomotion. Lastly, we briefly describe the role of somatosensory feedback in the recovery of locomotion after neurological injury. We highlight the fact that somatosensory feedback is an essential component of a highly integrated system for locomotor control. © 2021 American Physiological Society. Compr Physiol 11:1-71, 2021.
Collapse
Affiliation(s)
- Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Quebec, Canada
| | - Turgay Akay
- Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| |
Collapse
|
25
|
Bertschinger R, Giboin LS, Gruber M. Endurance Trained Athletes Do Not per se Have Higher Hoffmann Reflexes Than Recreationally Active Controls. Front Physiol 2021; 12:736067. [PMID: 34867445 PMCID: PMC8633408 DOI: 10.3389/fphys.2021.736067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
The impact of endurance training on spinal neural circuitries remains largely unknown. Some studies have reported higher H-reflexes in endurance trained athletes and therefore, adaptations within the Ia afferent pathways after long term endurance training have been suggested. In the present study we tested the hypothesis that cyclists (n = 12) demonstrate higher Hoffmann reflexes (H-reflexes) compared to recreationally active controls (n = 10). Notwithstanding, highly significant differences in endurance performance (VO2peak: 60.6 for cyclists vs. 46.3 ml/min/kg for controls (p < 0.001) there was no difference in the size of the SOL H-reflex between cyclists and controls (Hmax/Mmax ratio 61.3 vs. 60.0%, respectively (p = 0.840). Further analyses of the H and M recruitment curves for SOL revealed a significant steeper slope of the M recruitment curve in the group of cyclists (76.2 ± 3.8° vs. 72.0 ± 4.4°, p = 0.046) without a difference in the H-recruitment curve (84.6 ± 3.0° vs. 85.0 ± 2.8°, p = 0.784) compared to the control group. Cycling is classified as an endurance sport and thus the findings of the present study do not further support the assumption that long-term aerobic training leads to a general increase of the H-reflex. Amongst methodological differences in assessing the H-reflex, the training-specific sensorimotor control of the endurance sport itself might differently affect the responsiveness of spinal motoneurons on Ia-afferent inputs.
Collapse
Affiliation(s)
- Raphael Bertschinger
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Louis-Solal Giboin
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Markus Gruber
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| |
Collapse
|
26
|
Manganotti P, Buoite Stella A, Ajcevic M, di Girolamo FG, Biolo G, Franchi MV, Monti E, Sirago G, Marusic U, Simunic B, Narici MV, Pisot R. Peripheral nerve adaptations to 10 days of horizontal bed rest in healthy young adult males. Am J Physiol Regul Integr Comp Physiol 2021; 321:R495-R503. [PMID: 34318712 DOI: 10.1152/ajpregu.00146.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Space analogs, such as bed rest, are used to reproduce microgravity-induced morphological and physiological changes and can be used as clinical models of prolonged inactivity. Nevertheless, nonuniform decreases in muscle mass and function have been frequently reported, and peripheral nerve adaptations have been poorly studied, although some of these mechanisms may be explained. Ten young healthy males (18-33 yr) underwent 10 days of horizontal bed rest. Peripheral neurophysiological assessments were performed bilaterally for the dominant (DL) and nondominant upper and lower limbs (N-DL) on the 1st and 10th day of bed rest, including ultrasound of the median, deep peroneal nerve (DPN), and common fibular nerve (CFN) , as well as a complete nerve conduction study (NCS) of the upper and lower limbs. Consistently, reduced F waves, suggesting peripheral nerve dysfunction, of both the peroneal (DL: P = 0.005, N-DL: P = 0.013) and tibial nerves (DL: P = 0.037, N-DL: P = 0.005) were found bilaterally, whereas no changes were observed in nerve ultrasound or other parameters of the NCS of both the upper and lower limbs. In these young healthy males, only the F waves, known to respond to postural changes, were significantly affected by short-term bed rest. These preliminary results suggest that during simulated microgravity, most changes occur at the muscle or central nervous system level. Since the assessment of F waves is common in clinical neurophysiological examinations, caution should be used when testing individuals after prolonged immobility.
Collapse
Affiliation(s)
- Paolo Manganotti
- Clinical Unit of Neurology, Department of Medicine, Surgery and Health Sciences, University Hospital of Trieste, University of Trieste, Trieste, Italy
| | - Alex Buoite Stella
- Clinical Unit of Neurology, Department of Medicine, Surgery and Health Sciences, University Hospital of Trieste, University of Trieste, Trieste, Italy
| | - Milos Ajcevic
- Clinical Unit of Neurology, Department of Medicine, Surgery and Health Sciences, University Hospital of Trieste, University of Trieste, Trieste, Italy.,Department of Engineering and Architecture, University of Trieste, Trieste, Italy
| | - Filippo Giorgio di Girolamo
- Clinica Medica, Azienda Sanitaria Universitaria Giuliano Isontina, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Gianni Biolo
- Clinica Medica, Azienda Sanitaria Universitaria Giuliano Isontina, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Martino V Franchi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Elena Monti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Giuseppe Sirago
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Uros Marusic
- Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia.,Department of Health Sciences, Alma Mater Europaea - European Center Maribor, Maribor, Slovenia
| | - Bostjan Simunic
- Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia
| | - Marco V Narici
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia
| | - Rado Pisot
- Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia
| |
Collapse
|
27
|
Worthington A, Kalteniece A, Ferdousi M, D’Onofrio L, Dhage S, Azmi S, Adamson C, Hamdy S, Malik RA, Calcutt NA, Marshall AG. Optimal Utility of H-Reflex RDD as a Biomarker of Spinal Disinhibition in Painful and Painless Diabetic Neuropathy. Diagnostics (Basel) 2021; 11:1247. [PMID: 34359330 PMCID: PMC8306975 DOI: 10.3390/diagnostics11071247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/27/2021] [Accepted: 07/07/2021] [Indexed: 11/20/2022] Open
Abstract
Impaired rate-dependent depression of the Hoffman reflex (HRDD) is a potential biomarker of impaired spinal inhibition in patients with painful diabetic neuropathy. However, the optimum stimulus-response parameters that identify patients with spinal disinhibition are currently unknown. We systematically compared HRDD, performed using trains of 10 stimuli at five stimulation frequencies (0.3, 0.5, 1, 2 and 3 Hz), in 42 subjects with painful and 62 subjects with painless diabetic neuropathy with comparable neuropathy severity, and 34 healthy controls. HRDD was calculated using individual and mean responses compared to the initial response. At stimulation frequencies of 1, 2 and 3 Hz, HRDD was significantly impaired in patients with painful diabetic neuropathy compared to patients with painless diabetic neuropathy for all parameters and for most parameters when compared to healthy controls. HRDD was significantly enhanced in patients with painless diabetic neuropathy compared to controls for responses towards the end of the 1 Hz stimulation train. Receiver operating characteristic curve analysis in patients with and without pain showed that the area under the curve was greatest for response averages of stimuli 2-4 and 2-5 at 1 Hz, AUC = 0.84 (95%CI 0.76-0.92). Trains of 5 stimuli delivered at 1 Hz can segregate patients with painful diabetic neuropathy and spinal disinhibition, whereas longer stimulus trains are required to segregate patients with painless diabetic neuropathy and enhanced spinal inhibition.
Collapse
Affiliation(s)
- Anne Worthington
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.W.); (S.H.)
| | - Alise Kalteniece
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.K.); (M.F.); (S.D.); (S.A.); (R.A.M.)
| | - Maryam Ferdousi
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.K.); (M.F.); (S.D.); (S.A.); (R.A.M.)
| | - Luca D’Onofrio
- Department of Experimental Medicine, Sapienza University, 00185 Rome, Italy;
| | - Shaishav Dhage
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.K.); (M.F.); (S.D.); (S.A.); (R.A.M.)
| | - Shazli Azmi
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.K.); (M.F.); (S.D.); (S.A.); (R.A.M.)
- Diabetes Centre, Manchester University NHS Foundation Trust, Manchester M13 0JE, UK;
| | - Clare Adamson
- Diabetes Centre, Manchester University NHS Foundation Trust, Manchester M13 0JE, UK;
| | - Shaheen Hamdy
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.W.); (S.H.)
| | - Rayaz A. Malik
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (A.K.); (M.F.); (S.D.); (S.A.); (R.A.M.)
- Weill Cornell Medicine-Qatar, Research Division, Qatar Foundation, Education City, Doha 24144, Qatar
| | - Nigel A. Calcutt
- Department of Pathology, University of California, San Diego, CA 92093-0612, USA;
| | - Andrew G. Marshall
- Division of Neuroscience and Experimental Psychology, Faculty of Medical and Human Sciences, University of Manchester, Manchester M13 9PL, UK
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK
| |
Collapse
|
28
|
Sanderson A, Wang SF, Elgueta-Cancino E, Martinez-Valdes E, Sanchis-Sanchez E, Liew B, Falla D. The effect of experimental and clinical musculoskeletal pain on spinal and supraspinal projections to motoneurons and motor unit properties in humans: A systematic review. Eur J Pain 2021; 25:1668-1701. [PMID: 33964047 DOI: 10.1002/ejp.1789] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/30/2020] [Accepted: 04/24/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND OBJECTIVE Numerous studies have examined the influence of pain on spinal reflex excitability, motor unit behaviour and corticospinal excitability. Nevertheless, there are inconsistencies in the conclusions made. This systematic review sought to understand the effect of pain on spinal and supraspinal projections to motoneurons and motor unit properties by examining the influence of clinical or experimental pain on the following three domains: H-reflex, corticospinal excitability and motor unit properties. DATABASES AND DATA TREATMENT MeSH terms and preselected keywords relating to the H-reflex, motor evoked potentials and motor unit decomposition in chronic and experimental pain were used to perform a systematic literature search using Cumulative Index of Nursing and Allied Health Literature (CINAHL), Excerpta Medica dataBASE (EMBASE), Web of Science, Medline, Google Scholar and Scopus databases. Two independent reviewers screened papers for inclusion and assessed the methodological quality using a modified Downs and Black risk of bias tool; a narrative synthesis and three meta-analyses were performed. RESULTS Sixty-one studies were included, and 17 different outcome variables were assessed across the three domains. Both experimental and clinical pain have no major influence on measures of the H-reflex, whereas experimental and clinical pain appeared to have differing effects on corticospinal excitability. Experimental pain consistently reduced motor unit discharge rate, a finding which was not consistent with data obtained from patients. The results indicate that when in tonic pain, induced via experimental pain models, inhibitory effects on motoneuron behaviour were evident. However, in chronic clinical pain populations, more varied responses were evident likely reflecting individual adaptations to chronic symptoms. SIGNIFICANCE This is a comprehensive systematic review and meta-analysis which synthesizes evidence on the influence of pain on spinal and supraspinal projections to motoneurons and motor unit properties considering measures of the H-reflex, corticospinal excitability and motor unit behaviour. The H-reflex is largely not influenced by the presence of either clinical or experimental pain. Whilst inhibitory effects on corticospinal excitability and motor unit behaviour were evident under experimental pain conditions, more variable responses were observed for people with painful musculoskeletal disorders.
Collapse
Affiliation(s)
- Andy Sanderson
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.,Department of Sport and Exercise Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Manchester, UK
| | - Shuwfen F Wang
- Graduate Institute and School of Physical Therapy, National Taiwan University, Taipei, Taiwan
| | - Edith Elgueta-Cancino
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Eduardo Martinez-Valdes
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Enrique Sanchis-Sanchez
- Department of Physiotherapy, Faculty of Physiotherapy, University of Valencia, Valencia, Spain
| | - Bernard Liew
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.,School of Sport, Rehabilitation and Exercise Sciences, Faculty of Physiotherapy, University of Essex, Colchester, UK
| | - Deborah Falla
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
29
|
Barss TS, Collins DF, Miller D, Pujari AN. Indirect Vibration of the Upper Limbs Alters Transmission Along Spinal but Not Corticospinal Pathways. Front Hum Neurosci 2021; 15:617669. [PMID: 34079443 PMCID: PMC8165249 DOI: 10.3389/fnhum.2021.617669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/19/2021] [Indexed: 01/15/2023] Open
Abstract
The use of upper limb vibration (ULV) during exercise and rehabilitation continues to gain popularity as a modality to improve function and performance. Currently, a lack of knowledge of the pathways being altered during ULV limits its effective implementation. Therefore, the aim of this study was to investigate whether indirect ULV modulates transmission along spinal and corticospinal pathways that control the human forearm. All measures were assessed under CONTROL (no vibration) and ULV (30 Hz; 0.4 mm displacement) conditions while participants maintained a small contraction of the right flexor carpi radialis (FCR) muscle. To assess spinal pathways, Hoffmann reflexes (H-reflexes) elicited by stimulation of the median nerve were recorded from FCR with motor response (M-wave) amplitudes matched between conditions. An H-reflex conditioning paradigm was also used to assess changes in presynaptic inhibition by stimulating the superficial radial (SR) nerve (5 pulses at 300Hz) 37 ms prior to median nerve stimulation. Cutaneous reflexes in FCR elicited by stimulation of the SR nerve at the wrist were also recorded. To assess corticospinal pathways, motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation of the contralateral motor cortex were recorded from the right FCR and biceps brachii (BB). ULV significantly reduced H-reflex amplitude by 15.7% for both conditioned and unconditioned reflexes (24.0 ± 15.7 vs. 18.4 ± 11.2% M max ; p < 0.05). Middle latency cutaneous reflexes were also significantly reduced by 20.0% from CONTROL (-1.50 ± 2.1% Mmax) to ULV (-1.73 ± 2.2% Mmax; p < 0.05). There was no significant effect of ULV on MEP amplitude (p > 0.05). Therefore, ULV inhibits cutaneous and H-reflex transmission without influencing corticospinal excitability of the forearm flexors suggesting increased presynaptic inhibition of afferent transmission as a likely mechanism. A general increase in inhibition of spinal pathways with ULV may have important implications for improving rehabilitation for individuals with spasticity (SCI, stroke, MS, etc.).
Collapse
Affiliation(s)
- Trevor S. Barss
- Human Neurophysiology Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - David F. Collins
- Human Neurophysiology Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Dylan Miller
- Human Neurophysiology Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Amit N. Pujari
- School of Engineering and Computer Science, University of Hertfordshire, Hatfield, United Kingdom
- Biomedical Engineering Laboratory, School of Engineering, University of Aberdeen, Aberdeen, United Kingdom
| |
Collapse
|
30
|
Does partial activation of the neuromuscular system induce cross-education training effect? Case of a pilot study on motor imagery and neuromuscular electrical stimulation. Eur J Appl Physiol 2021; 121:2337-2348. [PMID: 33997913 DOI: 10.1007/s00421-021-04710-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/05/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Cross education defines the gains observed in the contralateral limb following unilateral strength training of the other limb. The present study questioned the neural mechanisms associated with cross education following training by motor imagery (MI) or submaximal neuromuscular electrical stimulation (NMES), both representing a partial activation of the motor system as compared to conventional strength training. METHODS Twenty-seven participants were distributed in three groups: MI, NMES and control. Training groups underwent a training program of ten sessions in two weeks targeting plantar flexor muscles of one limb. In both legs, neuromuscular plasticity was assessed through maximal voluntary isometric contraction (MViC) and triceps surae electrophysiological responses evoked by electrical nerve stimulation (H-reflexes and V-waves). RESULTS NMES and MI training improved MViC torque of the trained limb by 11.3% (P < 0.001) and 13.8% (P < 0.001), respectively. MViC of the untrained limb increased by 10.3% (P < 0.003) in the MI group only, accompanied with increases in V-waves on both sides. In the NMES group, V-waves only increased in the trained limb. In the MI group, rest H-reflexes increased in both the trained and the untrained triceps suraes. CONCLUSION MI seems to be effective to induce cross education, probably because of the activation of cortical motor regions that impact the corticospinal neural drive of both trained and untrained sides. Conversely, submaximal NMES did not lead to cross education. The present results emphasize that cross education does not necessarily require muscle activity of the trained limb.
Collapse
|
31
|
Fadeev FO, Bashirov FV, Markosyan VA, Izmailov AA, Povysheva TV, Sokolov ME, Kuznetsov MS, Eremeev AA, Salafutdinov II, Rizvanov AA, Lee HJ, Islamov RR. Combination of epidural electrical stimulation with ex vivo triple gene therapy for spinal cord injury: a proof of principle study. Neural Regen Res 2021; 16:550-560. [PMID: 32985487 PMCID: PMC7996027 DOI: 10.4103/1673-5374.293150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/03/2019] [Accepted: 04/29/2020] [Indexed: 02/07/2023] Open
Abstract
Despite emerging contemporary biotechnological methods such as gene- and stem cell-based therapy, there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury. Our previous studies have demonstrated that transplantation of genetically engineered human umbilical cord blood mononuclear cells producing three recombinant therapeutic molecules, including vascular endothelial growth factor (VEGF), glial cell-line derived neurotrophic factor (GDNF), and neural cell adhesion molecule (NCAM) can improve morpho-functional recovery of injured spinal cord in rats and mini-pigs. To investigate the efficacy of human umbilical cord blood mononuclear cells-mediated triple-gene therapy combined with epidural electrical stimulation in the treatment of spinal cord injury, in this study, rats with moderate spinal cord contusion injury were intrathecally infused with human umbilical cord blood mononuclear cells expressing recombinant genes VEGF165, GDNF, NCAM1 at 4 hours after spinal cord injury. Three days after injury, epidural stimulations were given simultaneously above the lesion site at C5 (to stimulate the cervical network related to forelimb functions) and below the lesion site at L2 (to activate the central pattern generators) every other day for 4 weeks. Rats subjected to the combined treatment showed a limited functional improvement of the knee joint, high preservation of muscle fiber area in tibialis anterior muscle and increased H/M ratio in gastrocnemius muscle 30 days after spinal cord injury. However, beneficial cellular outcomes such as reduced apoptosis and increased sparing of the gray and white matters, and enhanced expression of heat shock and synaptic proteins were found in rats with spinal cord injury subjected to the combined epidural electrical stimulation with gene therapy. This study presents the first proof of principle study of combination of the multisite epidural electrical stimulation with ex vivo triple gene therapy (VEGF, GDNF and NCAM) for treatment of spinal cord injury in rat models. The animal protocols were approved by the Kazan State Medical University Animal Care and Use Committee (approval No. 2.20.02.18) on February 20, 2018.
Collapse
Affiliation(s)
- Filip Olegovich Fadeev
- Department of Medical Biology and Genetics, Kazan State Medical University, Kazan, Russia
| | | | | | | | | | | | | | | | | | | | - Hyun Joon Lee
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS, USA
- Research Service, G.V. (Sonny) Montgomery VA Medical Center, Jackson, MS, USA
| | | |
Collapse
|
32
|
Insights into the combination of neuromuscular electrical stimulation and motor imagery in a training-based approach. Eur J Appl Physiol 2021; 121:941-955. [PMID: 33417035 PMCID: PMC7892697 DOI: 10.1007/s00421-020-04582-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/10/2020] [Indexed: 11/29/2022]
Abstract
Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.
Collapse
|
33
|
Andrews JC, Sankar T, Stein RB, Roy FD. Characterizing the effect of low intensity transcranial magnetic stimulation on the soleus H-reflex at rest. Exp Brain Res 2020; 238:2725-2731. [PMID: 32955615 DOI: 10.1007/s00221-020-05879-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/08/2020] [Indexed: 11/30/2022]
Abstract
Modulation of a Hoffmann (H)-reflex following transcranial magnetic stimulation (TMS) has been used to assess the nature of signals transmitted from cortical centers to lower motor neurons. Further characterizing the recruitment and time-course of the TMS-induced effect onto the soleus H-reflex adds to the discussion of these pathways and may improve its utility in clinical studies. In 10 healthy controls, TMS was used to condition the soleus H-reflex using TMS intensities from 65 to 110% of the resting motor threshold (RMT). Early facilitation [- 5 to - 3 ms condition-test (C-T) interval] was evident when TMS was 110% of RMT (P < 0.05). By comparison, late facilitation (+ 10 to + 20 ms C-T interval) was several times larger and observed over a wider range of TMS intensities, including 65-110% of RMT. The early inhibition (- 3 to - 1 ms C-T interval) had a low TMS threshold and was elicited over a wide range of intensity from 65% to 95% of RMT (all P < 0.05). A second inhibitory phase was seen ~ 4 ms later (+ 1 to + 4 ms C-T intervals) and was only observed for a TMS intensity of 95% of RMT (P < 0.05). The present findings reaffirm that subthreshold TMS strongly modulates soleus motor neurons and demonstrates that distinct pathways can be selectively probed at discrete C-T intervals when using specific TMS intensities.
Collapse
Affiliation(s)
- Jennifer C Andrews
- Department of Surgery, University of Alberta Hospital, WMC 1C3.13, Edmonton, AB, T6G 2E1, Canada
| | - Tejas Sankar
- Division of Neurosurgery, University of Alberta, Edmonton, Canada
| | - Richard B Stein
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - François D Roy
- Department of Surgery, University of Alberta Hospital, WMC 1C3.13, Edmonton, AB, T6G 2E1, Canada.
| |
Collapse
|
34
|
Akbas T, Kim K, Doyle K, Manella K, Lee R, Spicer P, Knikou M, Sulzer J. Rectus femoris hyperreflexia contributes to Stiff-Knee gait after stroke. J Neuroeng Rehabil 2020; 17:117. [PMID: 32843057 PMCID: PMC7448457 DOI: 10.1186/s12984-020-00724-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 07/06/2020] [Indexed: 11/17/2022] Open
Abstract
Background Stiff-Knee gait (SKG) after stroke is often accompanied by decreased knee flexion angle during the swing phase. The decreased knee flexion has been hypothesized to originate from excessive quadriceps activation. However, it is unclear whether hyperreflexia plays a role in this activation. The goal of this study was to establish the relationship between quadriceps hyperreflexia and knee flexion angle during walking in post-stroke SKG. Methods The rectus femoris (RF) H-reflex was recorded in 10 participants with post-stroke SKG and 10 healthy controls during standing and walking at the pre-swing phase. In order to attribute the pathological neuromodulation to quadriceps muscle hyperreflexia and activation, healthy individuals voluntarily increased quadriceps activity using electromyographic (EMG) feedback during standing and pre-swing upon RF H-reflex elicitation. Results We observed a negative correlation (R = − 0.92, p = 0.001) between knee flexion angle and RF H-reflex amplitude in post-stroke SKG. In contrast, H-reflex amplitude in healthy individuals in presence (R = 0.47, p = 0.23) or absence (R = − 0.17, p = 0.46) of increased RF muscle activity was not correlated with knee flexion angle. We observed a body position-dependent RF H-reflex modulation between standing and walking in healthy individuals with voluntarily increased RF activity (d = 2.86, p = 0.007), but such modulation was absent post-stroke (d = 0.73, p = 0.296). Conclusions RF reflex modulation is impaired in post-stroke SKG. The strong correlation between RF hyperreflexia and knee flexion angle indicates a possible regulatory role of spinal reflex excitability in post-stroke SKG. Interventions targeting quadriceps hyperreflexia could help elucidate the causal role of hyperreflexia on knee joint function in post-stroke SKG.
Collapse
Affiliation(s)
- Tunc Akbas
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Kyoungsoon Kim
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Kathleen Doyle
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Kathleen Manella
- University of St. Augustine for Health Sciences, Austin, TX, USA
| | - Robert Lee
- St. David's Medical Center, Austin, TX, USA
| | - Patrick Spicer
- Seton Brain and Spine Institute, Ascension Texas, University of Texas at Austin, Austin, TX, USA
| | - Maria Knikou
- Graduate Center of the City University of New York and Physical Therapy Department, College of Staten Island, New York, NY, USA
| | - James Sulzer
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
| |
Collapse
|
35
|
Yurttutmuş Z, Ekici Zincirci D, Bardak AN, Topkara B, Aydın T, Karacan I, Türker KS. A stimulus rate that is not influenced by homosynaptic post-activation depression in chronic stroke. Somatosens Mot Res 2020; 37:271-276. [PMID: 32811248 DOI: 10.1080/08990220.2020.1807925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine a stimulus rate that is not influenced by homosynaptic post-activation depression for H-reflex studies in patients with chronic spasticity. MATERIALS AND METHODS A cohort of 15 chronic stroke patients with soleus spasticity who received inpatient treatment at our rehabilitation centre participated in this study. The effect of stimulus frequency related depression on H-reflex size was tested using four different stimulus rates (0.1, 0.2, 0.3 and 1 Hz). The affected sides stibial nerve was stimulated by a bipolar electrode. The H-reflex was recorded from the affected sideed sidee sidehe affected smine stimulus frequency related depression of H-reflex size, amplitude of the first H-reflex response (H1) was used as control and amplitude of the second H-reflex response (H2) as test. RESULTS H2 amplitude for frequency of 1 Hz, 0.3 Hz, 0.2 Hz and 0.1 Hz were 74.3, 84.1, 85.5 and 92.7% of H1, respectively. Depression of H2 amplitude was statistically significant for 1 Hz, 0.3 Hz and 0.2 Hz (p < 0.001, p = 0.002, p = 0.024, respectively). CONCLUSIONS Higher frequency stimulation of Ia afferents than 0.1 Hz induced a stimulus frequency-related depression of H-reflex size in patients with chronic spasticity. The optimal stimulus rate for H-reflex was found to be 0.1 Hz.
Collapse
Affiliation(s)
- Zeynep Yurttutmuş
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Dilara Ekici Zincirci
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Ayse Nur Bardak
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Betilay Topkara
- Physiology Department, Koç University School of Medicine, Istanbul, Turkey
| | - Tugba Aydın
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Ilhan Karacan
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Kemal S Türker
- Physiology Department, Koç University School of Medicine, Istanbul, Turkey
| |
Collapse
|
36
|
Pearcey GEP, Zehr EP. Repeated and patterned stimulation of cutaneous reflex pathways amplifies spinal cord excitability. J Neurophysiol 2020; 124:342-351. [PMID: 32579412 DOI: 10.1152/jn.00072.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Priming with patterned stimulation of antagonist muscle afferents induces modulation of spinal cord excitability as evidenced by changes in group Ia reciprocal inhibition. When assessed transiently with a condition-test pulse paradigm, stimulating cutaneous afferents innervating the foot reduces Ia presynaptic inhibition and facilitates soleus Hoffmann (H)-reflex amplitudes. Modulatory effects (i.e., priming) of longer lasting sensory stimulation of cutaneous afferents innervating the foot have yet to be examined. As a first step, we examined how priming with 20 min of patterned and alternating stimulation between the left and right foot affects spinal cord excitability. During priming, stimulus trains (550 ms; consisting of twenty-eight 1-ms pulses at 51 Hz, 1.2 times the radiating threshold) were applied simultaneously to the sural and plantar nerves of the ankle. Stimulation to the left and right ankle was out of phase by 500 ms. We evoked soleus H-reflexes and muscle compound action potentials (M waves) before and following priming stimulation to provide a proxy measure of spinal cord excitability. H-reflex and M-wave recruitment curves were recorded at rest, during brief (<2 min) arm cycling, and with sural conditioning [train of five 1-ms pulses at 2 times the radiating threshold (RT) with a condition-test interval (C-T) = 80 ms]. Data indicate an increase in H-reflex excitability following priming via patterned sensory stimulation. Transient sural conditioning was less effective following priming, indicating that the increased excitability of the H-reflex is partially attributable to reductions in group Ia presynaptic inhibition. Sensory stimulation to cutaneous afferents, which enhances spinal cord excitability, may prove useful in both rehabilitation and performance settings.NEW & NOTEWORTHY Priming via patterned stimulation of the nervous system induces neuroplasticity. Yet, accessing previously known cutaneous reflex pathways to alter muscle reflex excitability has not yet been examined. Here, we show that sensory stimulation of the cutaneous afferents that innervate the foot sole can amplify spinal cord excitability, which, in this case, is attributed to reductions in presynaptic inhibition.
Collapse
Affiliation(s)
- Gregory E P Pearcey
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, British Columbia, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, British Columbia, Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, British Columbia, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, British Columbia, Canada.,Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| |
Collapse
|
37
|
D Gonçalves A, Teodosio C, Pezarat-Correia P, Vila-Chã C, V Mendonca G. Effects of acute sleep deprivation on H reflex and V wave. J Sleep Res 2020; 30:e13118. [PMID: 32567138 DOI: 10.1111/jsr.13118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/01/2022]
Abstract
The impact of sleep deprivation on muscular strength and power remains poorly understood. We aimed to determine the acute effects of 24 hr of sleep deprivation on H-reflex and V-wave excitability. Fourteen healthy young adults (eight men, six women) were included. Participants visited the laboratory on two different occasions, without and with 24 hr of sleep deprivation. In each session, participants were tested for maximal voluntary contraction (MVC) of the plantar flexors and dorsiflexors, soleus H- and M-recruitment curves, and evoked V wave, as well as tibialis anterior/soleus electromyographic co-activation. Twenty-four hours of sleep deprivation did not affect either plantarflexion MVC or soleus electromyographic normalized amplitude (p > .05). Moreover, H-reflex and V-wave peak-to-peak normalized amplitude did not change with sleep deprivation (p > .05). Conversely, we obtained a significant increase in antagonist/agonist level of co-activation during MVC post-sleep deprivation (6.2 ± 5.2%, p < .01). In conclusion, we found that H-reflex and V-wave responses are well preserved after 24 hr of sleep deprivation, revealing that descending neural drive and/or modulation in Ia afferent input remains largely unaffected under these circumstances. Yet, sleep deprivation affects motor control by exacerbating the magnitude of antagonist/agonist co-activation during forceful muscle contractions and this is novel.
Collapse
Affiliation(s)
- André D Gonçalves
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Carolina Teodosio
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Carolina Vila-Chã
- Polytechnic Institute of Guarda, Guarda, Portugal.,Research Center in Sports Sciences, Health and Human Development (CIDESD), Vila-Real, Portugal
| | - Goncalo V Mendonca
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| |
Collapse
|
38
|
Ni Z, Vial F, Avram AV, Leodori G, Pajevic S, Basser PJ, Hallett M. Measuring conduction velocity distributions in peripheral nerves using neurophysiological techniques. Clin Neurophysiol 2020; 131:1581-1588. [PMID: 32417700 DOI: 10.1016/j.clinph.2020.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine how long it takes for neural impulses to travel along peripheral nerve fibers in living humans. METHODS A collision test was performed to measure the conduction velocity distribution of the ulnar nerve. Two stimuli at the distal and proximal sites were used to produce the collision. Compound muscle or nerve action potentials were recorded to perform the measurements on the motor or mixed nerve, respectively. Interstimulus interval was set at 1-5 ms. A quadri-pulse technique was used to measure the refractory period and calibrate the conduction time. RESULTS Compound muscle action potential produced by the proximal stimulation started to emerge at the interstimulus interval of about 1.5 ms and increased with the increment in interstimulus interval. Two groups of motor nerve fibers with different conduction velocities were identified. The mixed nerve showed a wider conduction velocity distribution with identification of more subgroups of nerve fibers than the motor nerve. CONCLUSIONS The conduction velocity distributions in high resolution on a peripheral motor and mixed nerve are different and this can be measured with the collision test. SIGNIFICANCE We provided ground truth data to verify the neuroimaging pipelines for the measurements of latency connectome in the peripheral nervous system.
Collapse
Affiliation(s)
- Zhen Ni
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States
| | - Felipe Vial
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States; Facultad de Medicina Clinica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Alexandru V Avram
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, United States
| | | | - Sinisa Pajevic
- Mathematical and Statistical Computing Laboratory, Center for Information Technology, National Institutes of Health, United States
| | - Peter J Basser
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States.
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States.
| |
Collapse
|
39
|
Pulverenti TS, Trajano GS, Walsh A, Kirk BJC, Blazevich AJ. Lack of cortical or Ia-afferent spinal pathway involvement in muscle force loss after passive static stretching. J Neurophysiol 2020; 123:1896-1906. [PMID: 32267196 DOI: 10.1152/jn.00578.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated whether modulation of corticospinal-motoneuronal excitability and/or synaptic transmission of the Ia afferent spinal reflex contributes to decreases in voluntary activation and muscular force after an acute bout of prolonged static muscle stretching. Fifteen men performed five 60-s constant-torque stretches (15-s rest intervals; total duration 5 min) of the plantar flexors on an isokinetic dynamometer and a nonstretching control condition in random order on 2 separate days. Maximum isometric plantar flexor torque and triceps surae muscle electromyographic activity (normalized to M wave; EMG/M) were simultaneously recorded immediately before and after each condition. Motor-evoked potentials (using transcranial magnetic stimulation) and H-reflexes were recorded from soleus during EMG-controlled submaximal contractions (23.4 ± 6.9% EMG maximum). No changes were detected in the control condition. After stretching, however, peak torque (mean ± SD; -14.3 ± 7.0%) and soleus EMG/M (-17.8 ± 6.2%) decreased, and these changes were highly correlated (r = 0.83). No changes were observed after stretching in soleus MEP or H-reflex amplitudes measured during submaximal contractions, and interindividual variability of changes was not correlated with changes in EMG activity or maximum torque. During EMG-controlled submaximal contractions, torque production was significantly decreased after stretching (-22.7 ± 15.0%), indicating a compromised muscular output. These data provide support that changes in the excitability of the corticospinal-motoneuronal and Ia afferent spinal reflex pathways do not contribute to poststretch neural impairment.NEW & NOTEWORTHY This study is the first to specifically examine potential sites underlying the decreases in neural activation of muscle and force production after a bout of muscle stretching. However, no changes were found in either the H-reflex or motor-evoked potential amplitude during submaximal contractions.
Collapse
Affiliation(s)
- Timothy S Pulverenti
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.,Department of Physical Therapy, College of Staten Island, The City University of New York, Staten Island, New York
| | - Gabriel S Trajano
- School of Exercise and Nutrition Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Andrew Walsh
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Benjamin J C Kirk
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| |
Collapse
|
40
|
Novel human models for elucidating mechanisms of rate-sensitive H-reflex depression. Biomed J 2020; 43:44-52. [PMID: 32200955 PMCID: PMC7090317 DOI: 10.1016/j.bj.2019.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 01/24/2019] [Accepted: 07/10/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND This study used novel human neurophysiologic models to investigate whether the mechanism of rate-sensitive H-reflex depression lies in the pre-synaptic or post-synaptic locus in humans. We hypothesized that pre-synaptic inhibition would suppress Ia afferents and H-reflexes without suppressing alpha motor neurons or motor evoked potentials (MEPs). In contrast, post-synaptic inhibition would suppress alpha motor neurons, thereby reducing H-reflexes and MEPs. METHODS We recruited 23 healthy adults with typical rate-sensitive H-reflex depression, 2 participants with acute sensory-impaired spinal cord injury (SCI) (to rule out influence of sensory stimulation on supra-spinal excitability), and an atypical cohort of 5 healthy adults without rate-sensitive depression. After a single electrical stimulation to the tibial nerve, we administered either a testing H-reflex or a testing MEP at 50-5000 ms intervals. RESULTS Testing MEPs were not diminished in healthy subjects with or without typical rate-sensitive H-reflex depression, or in subjects with sensory-impaired SCI. MEP responses were similar in healthy subjects with versus without rate-sensitive H-reflex depression. CONCLUSIONS Results from these novel in vivo human models support a pre-synaptic locus of rate-sensitive H-reflex depression for the first time in humans. Spinal reflex excitability can be modulated separately from descending corticospinal influence. Each represents a potential target for neuromodulatory intervention.
Collapse
|
41
|
Therapeutic Elastic Tapes Applied in Different Directions Over the Triceps Surae Do Not Modulate Reflex Excitability of the Soleus Muscle. J Sport Rehabil 2020; 30:22-29. [PMID: 32087597 DOI: 10.1123/jsr.2018-0435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 11/06/2019] [Accepted: 01/02/2020] [Indexed: 11/18/2022]
Abstract
CONTEXT Elastic taping has been widely used for either to facilitate or to inhibit muscle contraction. The efficacy of elastic taping is allegedly ascribed to physiological mechanisms related to subcutaneous tissue and muscle stimulation as a result of tape tension and direction. However, the underlying mechanisms that support the use of elastic taping are still unclear. OBJECTIVE To investigate changes in electrophysiological responses after 48 hours of tape application in different directions on the calf muscles of healthy individuals. DESIGN Within-subjects design. SETTING Research laboratory. PARTICIPANTS Twenty-seven physically active males (age 18.0 [4.2] y, height 1.65 [0.07] m, body mass 62.3 [10.3] kg) participated. INTERVENTIONS Soleus H-reflex responses were evoked through stimulation of the tibial posterior nerve with 2- to 4-second interval between stimuli (32 sweeps) for each condition (baseline: without tape; facilitation: tape applied from muscle origin to insertion; inhibition: tape applied from muscle insertion to origin). MAIN OUTCOME MEASURES The H-reflex amplitude values were normalized by the maximal direct response (Mmax). Parameters were estimated from a sigmoidal fit of the H-reflex recruitment curve (ascending limb). RESULTS No significant differences were found for the parameters derived from the recruitment curve of the H-reflex among the conditions (P > .05). CONCLUSIONS The authors' findings showed that, irrespective of the direction of tape application, the elastic tape applied over the triceps surae does not generate any significant alteration on the excitability of the reflex pathway for different subpopulations of motor units. The authors therefore suggest a re-examination of the current recommendations on taping direction in clinical and sports activities.
Collapse
|
42
|
Develle Y, Leblond H. Biphasic Effect of Buspirone on the H-Reflex in Acute Spinal Decerebrated Mice. Front Cell Neurosci 2020; 13:573. [PMID: 32009904 PMCID: PMC6974439 DOI: 10.3389/fncel.2019.00573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/12/2019] [Indexed: 11/13/2022] Open
Abstract
Pharmacological treatment facilitating locomotor expression will also have some effects on reflex expression through the modulation of spinal circuitry. Buspirone, a partial serotonin receptor agonist (5-HT1 A), was recently shown to facilitate and even trigger locomotor movements in mice after complete spinal lesion (Tx). Here, we studied its effect on the H-reflex after acute Tx in adult mice. To avoid possible impacts of anesthetics on H-reflex depression, experiments were performed after decerebration in un-anesthetized mice (N = 20). The H-reflex in plantar muscles of the hind paw was recorded after tibial nerve stimulation 2 h after Tx at the 8th thoracic vertebrae and was compared before and every 10 min after buspirone (8 mg/kg, i.p.) for 60 min (N = 8). Frequency-dependent depression (FDD) of the H-reflex was assessed before and 60 min after buspirone. Before buspirone, a stable H-reflex could be elicited in acute spinal mice and FDD of the H-reflex was observed at 5 and 10 Hz relative to 0.2 Hz, FDD was still present 60 min after buspirone. Early after buspirone, the H-reflex was significantly decreased to 69% of pre-treatment, it then increased significantly 30-60 min after treatment, reaching 170% 60 min after injection. This effect was not observed in a control group (saline, N = 5) and was blocked when a 5-HT1 A antagonist (NAD-299) was administered with buspirone (N = 7). Altogether results suggest that the reported pro-locomotor effect of buspirone occurs at a time where there is a 5-HT1 A receptors mediated reflex depression followed by a second phase marked by enhancement of reflex excitability.
Collapse
Affiliation(s)
- Yann Develle
- Department of Anatomy, CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hugues Leblond
- Department of Anatomy, CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| |
Collapse
|
43
|
Häfner SJ. Tumour travel tours - Why circulating cancer cells value company. Biomed J 2020; 43:1-7. [PMID: 32200951 PMCID: PMC7090313 DOI: 10.1016/j.bj.2020.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 02/03/2020] [Indexed: 12/17/2022] Open
Abstract
Welcome to the New Year and a new issue of the Biomedical Journal, where we learn that travelling with company boosts the metastatic potential of circulating tumour cells, as well as that a worm could be an excellent model to study antidiabetic drugs. In addition, we discover another pair of molecular scissors for genetic engineering, how exactly Leptospira wreaks havoc on its run through the host organism, and that hyperparathyroidism brings its own risks, but does not worsen the outcome of papillary thyroid carcinoma. Furthermore, the importance of taking into account differing beauty ideals for aesthetic surgery surveys is discussed, alongside the question how bad isolated local recurrence is in the case of HR + breast cancer. Finally, we find out that virtual colonoscopy deserves more credit, that the first medical experiment in space was all about the H-reflex, and that it is possible to survive advanced necrotising fasciitis of the face and neck.
Collapse
Affiliation(s)
- Sophia Julia Häfner
- University of Copenhagen, BRIC Biotech Research & Innovation Centre, Anders Lund Group, Copenhagen, Denmark.
| |
Collapse
|
44
|
Barss TS, Parhizi B, Mushahwar VK. Transcutaneous spinal cord stimulation of the cervical cord modulates lumbar networks. J Neurophysiol 2020; 123:158-166. [DOI: 10.1152/jn.00433.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been established that coordinated arm and leg (A&L) cycling facilitates corticospinal drive and modulation of cervico-lumbar connectivity and ultimately improves overground walking in people with incomplete spinal cord injury or stroke. This study examined the effect of noninvasive transcutaneous spinal cord stimulation (tSCS) on the modulation of cervico-lumbar connectivity. Thirteen neurologically intact adults participated in the study. The excitability of the Hoffmann (H) reflex elicited in the soleus muscle was examined under multiple conditions involving either the arms held in a static position or rhythmic arm cycling while tSCS was applied to either the cervical or lumbar cord. As expected, soleus H-reflex amplitude was significantly suppressed by 19.2% during arm cycling (without tSCS) relative to arms static (without tSCS). Interestingly, tSCS of the cervical cord with arms static significantly suppressed the soleus H-reflex (−22.9%), whereas tSCS over the lumbar cord did not suppress the soleus H-reflex (−3.8%). The combination of arm cycling with cervical or lumbar tSCS did not yield additional suppression of the soleus H-reflex beyond that obtained with arm cycling alone or cervical tSCS alone. The results demonstrate that activation of the cervical spinal cord through both rhythmic arm cycling and tonic tSCS significantly modulates the activity of lumbar networks. This highlights the potential for engaging cervical spinal cord networks through tSCS during rehabilitation interventions to enhance cervico-lumbar connectivity. This connectivity is influential in facilitating improvements in walking function after neurological impairment. NEW & NOTEWORTHY This is the first study to investigate the modulatory effects of transcutaneous spinal cord stimulation (tSCS) on cervico-lumbar connectivity. We report that both rhythmic activation of the cervical spinal cord through arm cycling and tonic activation of the cervical cord through tSCS significantly modulate the activity of lumbar networks. This suggests that engaging cervical spinal cord networks through tSCS during locomotor retraining interventions may not only enhance cervico-lumbar connectivity but also further improve walking capacity.
Collapse
Affiliation(s)
- Trevor S. Barss
- Neuroscience and Mental Health Institute, University of Alberta, AB, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB, Canada
| | - Behdad Parhizi
- Neuroscience and Mental Health Institute, University of Alberta, AB, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB, Canada
| | - Vivian K. Mushahwar
- Neuroscience and Mental Health Institute, University of Alberta, AB, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
45
|
Rao N, Parikh PJ. Fluctuations in Human Corticospinal Activity Prior to Grasp. Front Syst Neurosci 2019; 13:77. [PMID: 31920572 PMCID: PMC6933951 DOI: 10.3389/fnsys.2019.00077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/29/2019] [Indexed: 12/31/2022] Open
Abstract
Neuronal firing rate variability prior to movement onset contributes to trial-to-trial variability in primate behavior. However, in humans, whether similar mechanisms contribute to trial-to-trial behavioral variability remains unknown. We investigated the time-course of trial-to-trial variability in corticospinal excitability (CSE) using transcranial magnetic stimulation (TMS) during a self-paced reach-to-grasp task. We hypothesized that CSE variability will be modulated prior to the initiation of reach and that such a modulation would explain trial-to-trial behavioral variability. Able-bodied individuals were visually cued to plan their grip force before exertion of either 30% or 5% of their maximum pinch force capacity on an object. TMS was delivered at six time points (0.5, 0.75, 1, 1.1, 1.2, and 1.3 s) following a visual cue that instructed the force level. We first modeled the relation between CSE magnitude and its variability at rest (n = 12) to study the component of CSE variability pertaining to the task but not related to changes in CSE magnitude (n = 12). We found an increase in CSE variability from 1.2 to 1.3 s following the visual cue at 30% but not at 5% of force. This effect was temporally dissociated from the decrease in CSE magnitude that was observed from 0.5 to 0.75 s following the cue. Importantly, the increase in CSE variability explained at least ∼40% of inter-individual differences in trial-to-trial variability in time to peak force rate. These results were found to be repeatable across studies and robust to different analysis methods. Our findings suggest that the neural mechanisms underlying modulation in CSE variability and CSE magnitude are distinct. Notably, the extent of modulation in variability in corticospinal system prior to grasp within individuals may explain their trial-to-trial behavioral variability.
Collapse
Affiliation(s)
| | - Pranav J. Parikh
- Center for Neuromotor and Biomechanics Research, Department of Health and Human Performance, University of Houston, Houston, TX, United States
| |
Collapse
|
46
|
Effects of military basic training on VO2max, body composition, muscle strength and neural responses in conscripts of different aerobic condition. BIOMEDICAL HUMAN KINETICS 2019. [DOI: 10.2478/bhk-2019-0023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Summary
Study aim: The purpose of this study was to evaluate neuromuscular adaptations in conscripts with different fitness levels (VO2max) during 8 weeks of military basic training (BT).
Material and methods: Twenty-four male conscripts (18–21 years) were divided into two groups (Good Fitness [GF] and Low fitness [LF]) based on their VO2max at the beginning of BT. Body mass (BM), fat free mass (FFM) and Fat% were measured after 2, 4, and 7 weeks of training. VO2max, maximal isometric leg press force (MVC), H-reflex (Hmax/Mmax) at rest and V-wave (V/Mmax) during maximal isometric plantarflexion were measured from the soleus muscle at the beginning, after 5, and after 8 weeks of training.
Results: FFM decreased significantly in LF after 7 weeks of training (–3.0 ± 1.7%, p < 0.001), which was not observed in GF. Both GF (6.9 ± 4.6%, p < 0.01) and LF (5.7 ± 4.6%, p < 0.01) showed improved VO2max after 5 weeks, with no changes during the last 3 weeks. A main effect of training was observed in decreased leg press MVC (–7.3 ± 9.3%, F = 4.899, p < 0.05), with no between-group differences. V-wave was significantly lower in LF during 5 (–37.9%, p < 0.05) and 8 (–44.9%, p < 0.05) weeks.
Conclusion: Poor development of the neuromuscular system during BT suggests that explosive and/or maximal strength training should be added to the BT protocol for all conscripts regardless of fitness level. In addition, individualized training periodization should be considered to optimize the training load.
Collapse
|
47
|
Nguyen GL, Putnam S, Haile M, Raza Z, Bremer M, Wilkinson KA. Diet-induced obesity decreases rate-dependent depression in the Hoffmann's reflex in adult mice. Physiol Rep 2019; 7:e14271. [PMID: 31660698 PMCID: PMC6818099 DOI: 10.14814/phy2.14271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/01/2019] [Accepted: 10/02/2019] [Indexed: 12/23/2022] Open
Abstract
Obesity is associated with balance and motor control deficits. We have recently shown that Group Ia muscle spindle afferents, the sensory arm of the muscle stretch reflex, are less responsive in mice fed a high-fat diet. Here we test the hypothesis that reflex excitability to sensory information from Group Ia muscle spindle afferents is altered in a mouse model of diet-induced obesity. We measured the anesthetized Hoffmann's or H-reflex, the electrical analog of the muscle stretch reflex. Adult mice of both sexes were fed a control diet (CD; 10% kcal from fat) or a high-fat diet (HFD; 60% kcal from fat) for 5, 10, or 15 weeks. We used three quantitative measures of H-reflex excitability: (1) H-reflex latency; (2) the percentage of motor neurons recruited from electrical stimulation of Group Ia muscle spindle afferents (Hmax /Mmax ); and (3) rate-dependent depression (RDD), the decrease in H-reflex amplitude to high frequency stimulation (20 stimuli at 5 Hz). A HFD did not significantly alter H latency (P = 0.16) or Hmax /Mmax ratios (P = 0.06), but RDD was significantly lower in HFD compared to CD groups (P < 0.001). Interestingly, HFD males exhibited decreased RDD compared to controls only after 5 and 10 weeks of feeding, but females showed progressive decreases in RDD that were only significant at 10 and 15 weeks on the HFD. These results suggest that high-fat feeding increases H-reflex excitability. Future studies are needed to determine whether these changes alter muscle stretch reflex strength and/or balance and to determine the underlying mechanism(s).
Collapse
Affiliation(s)
- Gerard L. Nguyen
- Department of Biological SciencesSan José State UniversitySan JoseCalifornia
| | - Shea Putnam
- Department of Biological SciencesSan José State UniversitySan JoseCalifornia
| | - Mulatwa Haile
- Department of Biological SciencesSan José State UniversitySan JoseCalifornia
| | - Zahra Raza
- Department of Biological SciencesSan José State UniversitySan JoseCalifornia
| | - Martina Bremer
- Department of Mathematics and StatisticsSan José State UniversitySan JoseCalifornia
| | | |
Collapse
|
48
|
Miljković N. Optimal stimulation site selection for H‐reflex measurement: Comments on previously published paper. Muscle Nerve 2019; 60:E22. [DOI: 10.1002/mus.26615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Nadica Miljković
- Signals & Systems DepartmentUniversity of Belgrade – School of Electrical Engineering Belgrade Serbia
| |
Collapse
|
49
|
Grosprêtre S, Gimenez P, Mourot L, Coratella G. Elastic band exercise induces greater neuromuscular fatigue than phasic isometric contractions. J Electromyogr Kinesiol 2019; 47:113-120. [DOI: 10.1016/j.jelekin.2018.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 11/01/2018] [Accepted: 12/10/2018] [Indexed: 10/27/2022] Open
|
50
|
Modulation of soleus stretch reflexes during walking in people with chronic incomplete spinal cord injury. Exp Brain Res 2019; 237:2461-2479. [PMID: 31309252 PMCID: PMC6751142 DOI: 10.1007/s00221-019-05603-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/08/2019] [Indexed: 12/28/2022]
Abstract
In people with spasticity due to chronic incomplete spinal cord injury (SCI), it has been presumed that the abnormal stretch reflex activity impairs gait. However, locomotor stretch reflexes across all phases of walking have not been investigated in people with SCI. Thus, to understand modulation of stretch reflex excitability during spastic gait, we investigated soleus stretch reflexes across the entire gait cycle in nine neurologically normal participants and nine participants with spasticity due to chronic incomplete SCI (2.5–11 year post-injury). While the participant walked on the treadmill at his/her preferred speed, unexpected ankle dorsiflexion perturbations (6° at 250°/s) were imposed every 4–6 steps. The soleus H-reflex was also examined. In participants without SCI, spinal short-latency “M1”, spinal medium latency “M2”, and long-latency “M3” were clearly modulated throughout the step cycle; the responses were largest in the mid-stance and almost completely suppressed during the stance-swing transition and swing phases. In participants with SCI, M1 and M2 were abnormally large in the mid–late-swing phase, while M3 modulation was similar to that in participants without SCI. The H-reflex was also large in the mid–late-swing phase. Elicitation of H-reflex and stretch reflexes in the late swing often triggered clonus and affected the soleus activity in the following stance. In individuals without SCI, moderate positive correlation was found between H-reflex and stretch reflex sizes across the step cycle, whereas in participants with SCI, such correlation was weak to non-existing, suggesting that H-reflex investigation would not substitute for stretch reflex investigation in individuals after SCI.
Collapse
|