1
|
Dalrymple AN, Fisher LE, Weber DJ. A preliminary study exploring the effects of transcutaneous spinal cord stimulation on spinal excitability and phantom limb pain in people with a transtibial amputation. J Neural Eng 2024; 21:046058. [PMID: 39094627 DOI: 10.1088/1741-2552/ad6a8d] [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: 10/21/2023] [Accepted: 08/02/2024] [Indexed: 08/04/2024]
Abstract
Objective. Phantom limb pain (PLP) is debilitating and affects over 70% of people with lower-limb amputation. Other neuropathic pain conditions correspond with increased spinal excitability, which can be measured using reflexes andF-waves. Spinal cord neuromodulation can be used to reduce neuropathic pain in a variety of conditions and may affect spinal excitability, but has not been extensively used for treating PLP. Here, we propose using a non-invasive neuromodulation method, transcutaneous spinal cord stimulation (tSCS), to reduce PLP and modulate spinal excitability after transtibial amputation.Approach. We recruited three participants, two males (5- and 9-years post-amputation, traumatic and alcohol-induced neuropathy) and one female (3 months post-amputation, diabetic neuropathy) for this 5 d study. We measured pain using the McGill Pain Questionnaire (MPQ), visual analog scale (VAS), and pain pressure threshold (PPT) test. We measured spinal reflex and motoneuron excitability using posterior root-muscle (PRM) reflexes andF-waves, respectively. We delivered tSCS for 30 min d-1for 5 d.Main Results. After 5 d of tSCS, MPQ scores decreased by clinically-meaningful amounts for all participants from 34.0 ± 7.0-18.3 ± 6.8; however, there were no clinically-significant decreases in VAS scores. Two participants had increased PPTs across the residual limb (Day 1: 5.4 ± 1.6 lbf; Day 5: 11.4 ± 1.0 lbf).F-waves had normal latencies but small amplitudes. PRM reflexes had high thresholds (59.5 ± 6.1μC) and low amplitudes, suggesting that in PLP, the spinal cord is hypoexcitable. After 5 d of tSCS, reflex thresholds decreased significantly (38.6 ± 12.2μC;p< 0.001).Significance. These preliminary results in this non-placebo-controlled study suggest that, overall, limb amputation and PLP may be associated with reduced spinal excitability and tSCS can increase spinal excitability and reduce PLP.
Collapse
Affiliation(s)
- Ashley N Dalrymple
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
- NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
- Department of Physical Medicine & Rehabilitation, University of Utah, Salt Lake City, UT, United States of America
- NERVES Lab, University of Utah, Salt Lake City, UT, United States of America
| | - Lee E Fisher
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Douglas J Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
- NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, United States of America
| |
Collapse
|
2
|
Lewis MJ. Electrodiagnostic testing in dogs with disorders of the spinal cord or cauda equina. Vet J 2024; 304:106082. [PMID: 38360137 DOI: 10.1016/j.tvjl.2024.106082] [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: 09/12/2023] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 02/17/2024]
Abstract
Electrodiagnostic (EDX) testing is uncommonly utilized in dogs other than for investigation of disorders of the neuromuscular system. In dogs with diseases affecting the spinal cord or cauda equina, EDX testing can provide functional data complementary to imaging information that together can guide therapeutic and management approaches. Additionally, in some clinical scenarios, EDX testing prior to advanced imaging is integral to identifying if there is spinal cord or cauda equina involvement and can aid in determining the appropriate diagnostic path. This review will outline EDX testing methods that have been reported in dogs relating to the diagnosis, monitoring or prognosis of various conditions affecting the spinal cord and cauda equina. The various tests will be briefly outlined regarding how they are performed and what information is provided. The main focus will be on clinical applications including highlighting situations where EDX testing is useful for differentiating between neurologic and non-neurologic presentations. Additional ways these EDX techniques could be incorporated in the management of diseases of the spinal cord and cauda equina in dogs will be presented.
Collapse
Affiliation(s)
- M J Lewis
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr, Raleigh, NC 27607, USA.
| |
Collapse
|
3
|
McKeown DJ, Stewart GM, Kavanagh JJ. The severity of acute hypoxaemia determines distinct changes in intracortical and spinal neural circuits. Exp Physiol 2023; 108:1203-1214. [PMID: 37548581 PMCID: PMC10988465 DOI: 10.1113/ep091224] [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: 03/20/2023] [Accepted: 07/25/2023] [Indexed: 08/08/2023]
Abstract
The purpose of this study was to examine how two common methods of continuous hypoxaemia impact the activity of intracortical circuits responsible for inhibition and facilitation of motor output, and spinal excitability. Ten participants were exposed to 2 h of hypoxaemia at 0.13 fraction of inspired oxygen (F I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol) and 80% of peripheral capillary oxygen saturation (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol) using a simulating altitude device on two visits separated by a week. Using transcranial magnetic and peripheral nerve stimulation, unconditioned motor evoked potential (MEP) area, short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), and F-wave persistence and area were assessed in the first dorsal interosseous (FDI) muscle before titration, after 1 and 2 h of hypoxic exposure, and at reoxygenation. The clamping protocols resulted in differing reductions inS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ by 2 h (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol: 81.9 ± 1.3%,F I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol: 90.6 ± 2.5%). Although unconditioned MEP peak to peak amplitude and area did not differ between the protocols, SICI duringF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping was significantly lower at 2 h compared toS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping (P = 0.011) and baseline (P < 0.001), whereas ICF was higher throughout theF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping compared toS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping (P = 0.005). Furthermore, a negative correlation between SICI andS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ (rrm = -0.56, P = 0.002) and a positive correlation between ICF andS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ (rrm = 0.69, P = 0.001) were determined, where greater reductions inS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ correlated with less inhibition and less facilitation of MEP responses. Although F-wave area progressively increased similarly throughout the protocols (P = 0.037), persistence of responses was reduced at 2 h and reoxygenation (P < 0.01) during theS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol compared to theF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol. After 2 h of hypoxic exposure, there is a reduction in the activity of intracortical circuits responsible for inhibiting motor output, as well as excitability of spinal motoneurones. However, these effects can be influenced by other physiological responses to hypoxia (i.e., hyperventilation and hypocapnia). NEW FINDINGS: What is the central question of this study? How do two common methods of acute hypoxic exposure influence the excitability of intracortical networks and spinal circuits responsible for motor output? What is the main finding and its importance? The excitability of spinal circuits and intracortical networks responsible for inhibition of motor output was reduced during severe acute exposure to hypoxia at 2 h, but this was not seen during less severe exposure. This provides insight into the potential cause of variance seen in motor evoked potential responses to transcranial magnetic stimulation (corticospinal excitability measures) when exposed to hypoxia.
Collapse
Affiliation(s)
- Daniel J. McKeown
- Neural Control of Movement LaboratoryMenzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
- Department of PsychologyFaculty of Society and DesignBond UniversityGold CoastQueenslandAustralia
| | - Glenn M. Stewart
- Menzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
- Allied Health Research CollaborativeThe Prince Charles HospitalBrisbaneQueenslandAustralia
- Charles Perkins CentreThe University of SydneySydneyNew South WalesAustralia
| | - Justin J. Kavanagh
- Neural Control of Movement LaboratoryMenzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
| |
Collapse
|
4
|
Paired corticomotoneuronal stimulation of the preactivated ankle dorsiflexor: an open-label study of magnetic and electrical painless protocols. Exp Brain Res 2023; 241:629-647. [PMID: 36637488 DOI: 10.1007/s00221-022-06534-0] [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: 07/10/2022] [Accepted: 12/20/2022] [Indexed: 01/14/2023]
Abstract
Paired corticomotoneuronal stimulation (or electrical PCMS: ePCMS) is the repetitive pairing of an electrical stimulus to a nerve with a transcranial magnetic stimulation of the primary motor cortex (TMS-of-M1) to noninvasively influence spinal plasticity. We compared ePCMS with the new painless PCMS protocol pairing a magnetic stimulus to the nerve with TMS-of-M1 (mPCMS) in the preactivated tibial anterior muscle (TA). Sixteen healthy adults participated in two sessions (mPCMS, ePCMS), each with 180 pairs of [low-intensity TMS-of-M1 + nerve stimulation] at 0.2 Hz. TA motor-evoked potentials (MEP) to single-pulse TMS at pre-PCMS, immediately and 30 min after PCMS, were cluster-analyzed to discriminate responders and non-responders. Paired-pulse TMS-of-M1 and F-waves were also tested and BDNF polymorphism influence was explored. Both PCMS protocols significantly increased MEP amplitudes (n = 9 responders each), but the time-course differed with mPCMS inducing larger MEP increase over time. The number of BDNF-methionine carriers tended to be larger than Val66Val in mPCMS and the reverse in ePCMS, thus warranting further investigations. The MEP changes of the preactivated TA likely occurred at the pre-motoneuronal level and larger mPCMS after-effects over time may be related to the afferents recruited. mPCMS seems relevant to be tested in future studies as a painless noninvasive approach to induce sustained pre-motoneuronal plasticity in spinal cord injury.
Collapse
|
5
|
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
|
6
|
Elias LA, Hur P, Sieck GC. Editorial: Towards an understanding of spinal and corticospinal pathways and mechanisms. Front Hum Neurosci 2023; 17:1181647. [PMID: 37025971 PMCID: PMC10070955 DOI: 10.3389/fnhum.2023.1181647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Affiliation(s)
- Leonardo Abdala Elias
- Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas, Campinas, SP, Brazil
- Neural Engineering Research Laboratory, Center for Biomedical Engineering, University of Campinas, Campinas, SP, Brazil
- *Correspondence: Leonardo Abdala Elias
| | - Pilwon Hur
- School of Mechanical Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Gary C. Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| |
Collapse
|
7
|
Oda H, Tsujinaka R, Fukuda S, Sawaguchi Y, Hiraoka K. Tactile perception of right middle fingertip suppresses excitability of motor cortex supplying right first dorsal interosseous muscle. Neuroscience 2022; 494:82-93. [PMID: 35588919 DOI: 10.1016/j.neuroscience.2022.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Abstract
The present study examined whether tactile perception of the fingertip modulates excitability of the motor cortex supplying the intrinsic hand muscle and whether this modulation is specific to the fingertip stimulated and the muscle and hand tested. Tactile stimulation was given to one of the five fingertips in the left or right hand, and transcranial magnetic stimulation eliciting motor evoked potential in the first dorsal interosseous muscle (FDI) or abductor digiti minimi was given 200 ms after the onset of tactile stimulation. The corticospinal excitability of the FDI at rest was suppressed by the tactile stimulation of the right middle fingertip, but such suppression was absent for the other fingers stimulated and for the other muscle or hand tested. The persistence and amplitude of the F-wave was not significantly influenced by tactile stimulation of the fingertip in the right hand. These findings indicate that tactile perception of the right middle fingertip suppresses excitability of the motor cortex supplying the right FDI at rest. The suppression of corticospinal excitability was absent during tonic contraction of the right FDI, indicating that the motor execution process interrupts the tactile perception-induced suppression of motor cortical excitability supplying the right FDI. These findings are in line with a view that the tactile perception of the right middle finger induces surround inhibition of the motor cortex supplying the prime mover of the finger neighboring the stimulated finger.
Collapse
Affiliation(s)
- Hitoshi Oda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Ryo Tsujinaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Shiho Fukuda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Yasushi Sawaguchi
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University, Habikino city, Osaka, Japan.
| |
Collapse
|
8
|
Thorstensen JR, Taylor JL, Kavanagh JJ. 5-HT 2 receptor antagonism reduces human motoneuron output to antidromic activation but not to stimulation of corticospinal axons. Eur J Neurosci 2022; 56:3674-3686. [PMID: 35445439 PMCID: PMC9543143 DOI: 10.1111/ejn.15672] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/19/2022] [Accepted: 04/07/2022] [Indexed: 12/01/2022]
Abstract
The intrinsic electrical properties of motoneurons strongly affect motoneuron excitability to fast-acting excitatory ionotropic inputs. Serotonin (5-HT) is a neurochemical that alters the intrinsic properties of motoneurons, whereby animal models and in vitro experiments indicate that 5-HT increases motoneuron excitability by activating 5-HT2 receptors on the somato-dendritic compartment. In the current study, we examined how antagonism of the 5-HT2 receptor affects motoneuron excitability in humans. We hypothesised that motoneuron excitability would be reduced. The 5-HT2 antagonist cyproheptadine was administered to ten healthy participants in a double-blinded, placebo-controlled, crossover trial. Electrical cervicomedullary stimulation was used to deliver a synchronised excitatory volley to motoneurons to elicit cervicomedullary motor evoked potentials (CMEPs) in the surface electromyography (EMG) signal of the resting biceps brachii. Likewise, electrical peripheral nerve stimulation was used to generate antidromic spikes in motoneurons and cause recurrent discharges, which were recorded with surface EMG as F-waves in a resting hand muscle. Compared to placebo, we found that 5-HT2 antagonism reduced the amplitude and persistence of F-waves but did not affect CMEP amplitude. 5-HT2 antagonism also reduced maximal contraction strength. The reduced recurrent discharge of motoneurons with 5-HT2 antagonism suggests that 5-HT2 receptors modulate the electrical properties of the initial segment or soma to promote excitability. Conversely, as cyproheptadine did not affect motoneuron excitability to brief synaptic input, but affected maximal contractions requiring sustained input, it seems likely that the 5-HT2 mediated amplification of synaptic input at motoneuron dendrites is functionally significant only when excitatory input activates persistent inward currents.
Collapse
Affiliation(s)
- Jacob R Thorstensen
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Janet L Taylor
- School of Medical and Health Sciences, Edith Cowan University, Perth, Australia.,Neuroscience Research Australia, Sydney, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| |
Collapse
|
9
|
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
|
10
|
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
|
11
|
Rothwell J, Antal A, Burke D, Carlsen A, Georgiev D, Jahanshahi M, Sternad D, Valls-Solé J, Ziemann U. Central nervous system physiology. Clin Neurophysiol 2021; 132:3043-3083. [PMID: 34717225 PMCID: PMC8863401 DOI: 10.1016/j.clinph.2021.09.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022]
Abstract
This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.
Collapse
Affiliation(s)
- John Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK,Corresponding author at: Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, (J. Rothwell)
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Germany
| | - David Burke
- Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney 2050, Australia
| | - Antony Carlsen
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Dejan Georgiev
- Department of Neurology, University Medical Centre Ljubljana, Slovenia
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Dagmar Sternad
- Departments of Biology, Electrical & Computer Engineering, and Physics, Northeastern University, Boston, MA 02115, USA
| | - Josep Valls-Solé
- Institut d’Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Ulf Ziemann
- Department of Neurology and Stroke, and Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
| |
Collapse
|
12
|
Wecht JR, Savage WM, Famodimu GO, Mendez GA, Levine JM, Maher MT, Weir JP, Wecht JM, Carmel JB, Wu YK, Harel NY. Posteroanterior Cervical Transcutaneous Spinal Cord Stimulation: Interactions with Cortical and Peripheral Nerve Stimulation. J Clin Med 2021; 10:jcm10225304. [PMID: 34830584 PMCID: PMC8623612 DOI: 10.3390/jcm10225304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 12/27/2022] Open
Abstract
Transcutaneous spinal cord stimulation (TSCS) has demonstrated potential to beneficially modulate spinal cord motor and autonomic circuitry. We are interested in pairing cervical TSCS with other forms of nervous system stimulation to enhance synaptic plasticity in circuits serving hand function. We use a novel configuration for cervical TSCS in which the anode is placed anteriorly over ~C4–C5 and the cathode posteriorly over ~T2–T4. We measured the effects of single pulses of TSCS paired with single pulses of motor cortex or median nerve stimulation timed to arrive at the cervical spinal cord at varying intervals. In 13 participants with and 15 participants without chronic cervical spinal cord injury, we observed that subthreshold TSCS facilitates hand muscle responses to motor cortex stimulation, with a tendency toward greater facilitation when TSCS is timed to arrive at cervical synapses simultaneously or up to 10 milliseconds after cortical stimulus arrival. Single pulses of subthreshold TSCS had no effect on the amplitudes of median H-reflex responses or F-wave responses. These findings support a model in which TSCS paired with appropriately timed cortical stimulation has the potential to facilitate convergent transmission between descending motor circuits, segmental afferents, and spinal motor neurons serving the hand. Studies with larger numbers of participants and repetitively paired cortical and spinal stimulation are needed.
Collapse
Affiliation(s)
- Jaclyn R. Wecht
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - William M. Savage
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - Grace O. Famodimu
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - Gregory A. Mendez
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - Jonah M. Levine
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - Matthew T. Maher
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
| | - Joseph P. Weir
- Department of Health, Sport & Exercise Sciences, University of Kansas, Lawrence, KS 66045, USA;
| | - Jill M. Wecht
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
- Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jason B. Carmel
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA;
| | - Yu-Kuang Wu
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
- Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Noam Y. Harel
- James J. Peters VA Medical Center, Bronx, NY 10468, USA; (J.R.W.); (W.M.S.); (G.O.F.); (G.A.M.); (J.M.L.); (M.T.M.); (J.M.W.); (Y.-K.W.)
- Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Correspondence:
| |
Collapse
|
13
|
Miyara K, Etoh S, Kawamura K, Maruyama A, Kuronita T, Ohwatashi A, Shimodozono M. Effects of lower limb segmental muscle vibration on primary motor cortex short-latency intracortical inhibition and spinal excitability in healthy humans. Exp Brain Res 2021; 240:311-320. [PMID: 34724095 DOI: 10.1007/s00221-021-06257-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 10/23/2021] [Indexed: 12/19/2022]
Abstract
We examined the effects of lower limb segmental muscle vibration (SMV) on intracortical and spinal excitability in 13 healthy participants (mean age: 34.9 ± 7.8 years, 12 males, 1 female). SMV at 30 Hz was applied to the hamstrings, gastrocnemius, and soleus muscles for 5 min. Paired-pulse transcranial magnetic stimulation protocols were used to investigate motor-evoked potential (MEP) amplitude, short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF) from the abductor hallucis muscle (AbdH). These assessments were compared to the results of a control experiment (i.e., non-vibration) in the same participants. F-waves were evaluated from the AbdH on the right (vibration side) and left (non-vibration side) sides, and we calculated the ratio of the F-wave amplitude to the M-response amplitude (F/M ratio). These assessments were obtained before, immediately after, and 10, 20, and 30 min after SMV. For SICI, there was no change immediately after SMV, but there was a decrease over time (before vs. 30 min after, p = 0.021; immediately after vs. 30 min after, p = 0.015). There were no changes in test MEP amplitude, SICF, or the F/M ratio. SMV causes a gradual decrease in SICI over time perhaps owing to long-term potentiation. The present results may have implications for the treatment of spasticity.
Collapse
Affiliation(s)
- Kodai Miyara
- Department of Rehabilitation, Kagoshima University Hospital, 8-35-1, Sakuragaoka, Kagoshima-city, Kagoshima, 890-8520, Japan. .,Doctoral Program, Graduate School of Health Sciences, Kagoshima University, Kagoshima, Japan.
| | - Seiji Etoh
- Department of Rehabilitation and Physical Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kentaro Kawamura
- Department of Rehabilitation and Physical Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Atsuo Maruyama
- Department of Rehabilitation and Physical Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takehiro Kuronita
- Master's Program, Department of Rehabilitation and Physical Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiko Ohwatashi
- Faculty of Medicine, Course of Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, Japan
| | - Megumi Shimodozono
- Department of Rehabilitation and Physical Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| |
Collapse
|
14
|
Kumru H, Flores Á, Rodríguez-Cañón M, Edgerton VR, García L, Benito-Penalva J, Navarro X, Gerasimenko Y, García-Alías G, Vidal J. Cervical Electrical Neuromodulation Effectively Enhances Hand Motor Output in Healthy Subjects by Engaging a Use-Dependent Intervention. J Clin Med 2021; 10:E195. [PMID: 33430460 PMCID: PMC7827883 DOI: 10.3390/jcm10020195] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 12/12/2022] Open
Abstract
Electrical enabling motor control (eEmc) through transcutaneous spinal cord stimulation is a non-invasive method that can modify the functional state of the sensory-motor system. We hypothesize that eEmc delivery, together with hand training, improves hand function in healthy subjects more than either intervention alone by inducing plastic changes at spinal and cortical levels. Ten voluntary participants were included in the following three interventions: (i) hand grip training, (ii) eEmc, and (iii) eEmc with hand training. Functional evaluation included the box and blocks test (BBT) and hand grip maximum voluntary contraction (MVC), spinal and cortical motor evoked potential (sMEP and cMEP), and resting motor thresholds (RMT), short interval intracortical inhibition (SICI), and F wave in the abductor pollicis brevis muscle. eEmc combined with hand training retained MVC and increased F wave amplitude and persistency, reduced cortical RMT and facilitated cMEP amplitude. In contrast, eEmc alone only increased F wave amplitude, whereas hand training alone reduced MVC and increased cortical RMT and SICI. In conclusion, eEmc combined with hand grip training enhanced hand motor output and induced plastic changes at spinal and cortical level in healthy subjects when compared to either intervention alone. These data suggest that electrical neuromodulation changes spinal and, perhaps, supraspinal networks to a more malleable state, while a concomitant use-dependent mechanism drives these networks to a higher functional state.
Collapse
Affiliation(s)
- Hatice Kumru
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| | - África Flores
- Departament de Biologia Cel·lular, Fisiologia i Immunologia & Insititute of Neuroscience, Universitat Autònoma de Barcelona, and CIBERNED, Bellaterra, 08193 Barcelona, Spain; (Á.F.); (M.R.-C.)
| | - María Rodríguez-Cañón
- Departament de Biologia Cel·lular, Fisiologia i Immunologia & Insititute of Neuroscience, Universitat Autònoma de Barcelona, and CIBERNED, Bellaterra, 08193 Barcelona, Spain; (Á.F.); (M.R.-C.)
| | - Victor R. Edgerton
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Loreto García
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| | - Jesús Benito-Penalva
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| | - Xavier Navarro
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Departament de Biologia Cel·lular, Fisiologia i Immunologia & Insititute of Neuroscience, Universitat Autònoma de Barcelona, and CIBERNED, Bellaterra, 08193 Barcelona, Spain; (Á.F.); (M.R.-C.)
| | - Yury Gerasimenko
- Pavlov Institute of Physiology, 199034 St. Petersburg, Russia;
- Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40292, USA
| | - Guillermo García-Alías
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Departament de Biologia Cel·lular, Fisiologia i Immunologia & Insititute of Neuroscience, Universitat Autònoma de Barcelona, and CIBERNED, Bellaterra, 08193 Barcelona, Spain; (Á.F.); (M.R.-C.)
| | - Joan Vidal
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Adscrit a la Universitat Autònoma de Barcelona, 08916 Badalona, Spain; (V.R.E.); (L.G.); (J.B.-P.); (X.N.); (G.G.-A.); (J.V.)
- Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
- Fundació Institut d’Investigació en Ciències de la Salut Germans Trias i Pujol, 08916 Badalona, Spain
| |
Collapse
|
15
|
Mohammed NH, Hamdan FB, Al-Mahdawi AM. Evaluation of F wave and split hand index in patients with amyotrophic lateral sclerosis. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2020. [DOI: 10.1186/s41983-020-00191-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Amyotrophic lateral sclerosis (ALS) is characterized by gradual disturbance of both upper and lower motor neurons (LMN). In ALS, muscle wasting favors the abductor pollicis brevis (APB) and first dorsal interosseous (FDI), with relative preservation of abductor digiti minimi (ADM).
Objectives
To interpret F wave changes in the context of upper and LMN dysfunction and the differences in dysfunction between spinal motoneurons innervating the APB and ADM.
Patients and methods
Forty-four subjects were studied (22 patients with ALS and 22 controls). F wave was elicited by 50 electrical stimuli from the median and ulnar nerves, and the split hand index (SHI) was measured.
Results
F latency mean, median, and maximum and F amplitude mean, median, and maximum F/M amplitude ratio were increased in patients with versus those without pyramidal signs. Limb-onset ALS patients showed the biggest reduction in SHI. The APB muscle of patients with no detectable wasting and upper MN (UMN) signs showed reduced F wave persistence, mean F wave latency and amplitudes, increased index repeater neuron and index F repeater, and mean F/M amplitude ratio.
Conclusion
There is enhanced segmental motoneuronal excitability following UMN dysfunctions. SHI appears to be a diagnostic biomarker for ALS. Abnormal F parameters recorded from APB muscle can distinct patients with ALS from the normal controls to a greater extent than do the APB/ADM and FDI/ADM compound muscle action potential amplitude ratios.
Collapse
|
16
|
Takahara T, Yamaguchi H, Seki K, Onodera S. Sensory gating and suppression of subjective peripheral sensations during voluntary muscle contraction. BMC Neurosci 2020; 21:41. [PMID: 33003995 PMCID: PMC7528260 DOI: 10.1186/s12868-020-00592-2] [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: 05/12/2020] [Accepted: 09/23/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND During voluntary muscle contraction, sensory information induced by electrostimulation of the nerves supplying the contracting muscle is inhibited and the somatosensory evoked potentials (SEPs) amplitude decreases. This depression of sensory input during voluntary muscle contraction has been demonstrated by many studies using electrophysiological methods. However, the association between the electrophysiological response of the sensory system during sustained muscle contraction and subjective peripheral sensation (SPS) is still unclear. The aim of this study was to investigate changes in spinal excitability, SEPs, and SPS during voluntary muscle contraction. RESULTS The appearance rate of the F-wave was significantly higher during muscle contraction than rest, whereas no significant difference was observed in F-wave latency between muscle contraction and rest. Furthermore, the P25 amplitude of SEPs was significantly lower during muscle contraction than rest, whereas the N20 amplitude of SEPs exhibited no significant differences. The SPS was significantly lower during muscle contraction than rest CONCLUSIONS: We conclude that sensory gating, which is found in the P25 component of SEPs during muscle contraction, is one of the neurophysiological mechanisms underlying the suppression of SPS.
Collapse
Affiliation(s)
- Terumasa Takahara
- Department of Sport Social Management, KIBI International University, 8 Igamachi, Takahashi, Okayama, 716-8508, Japan.
| | - Hidetaka Yamaguchi
- Department of Sport Social Management, KIBI International University, 8 Igamachi, Takahashi, Okayama, 716-8508, Japan
| | - Kazutoshi Seki
- Department of Human Health and Wellbeing, University of Marketing and Distribution Science, Kobe. 3-1 Gakuen-Nishimachi, Nishi-ku, Kobe, Hyogo, 651-2188, Japan
| | - Sho Onodera
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, 288 Matsushima, Kurashiki, Okayama, 701-0193, Japan
| |
Collapse
|
17
|
Christiansen L, Larsen MN, Madsen MJ, Grey MJ, Nielsen JB, Lundbye-Jensen J. Long-term motor skill training with individually adjusted progressive difficulty enhances learning and promotes corticospinal plasticity. Sci Rep 2020; 10:15588. [PMID: 32973251 PMCID: PMC7518278 DOI: 10.1038/s41598-020-72139-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 08/21/2020] [Indexed: 12/16/2022] Open
Abstract
Motor skill acquisition depends on central nervous plasticity. However, behavioural determinants leading to long lasting corticospinal plasticity and motor expertise remain unexplored. Here we investigate behavioural and electrophysiological effects of individually tailored progressive practice during long-term motor skill training. Two groups of participants practiced a visuomotor task requiring precise control of the right digiti minimi for 6 weeks. One group trained with constant task difficulty, while the other group trained with progressively increasing task difficulty, i.e. continuously adjusted to their individual skill level. Compared to constant practice, progressive practice resulted in a two-fold greater performance at an advanced task level and associated increases in corticospinal excitability. Differences were maintained 8 days later, whereas both groups demonstrated equal retention 14 months later. We demonstrate that progressive practice enhances motor skill learning and promotes corticospinal plasticity. These findings underline the importance of continuously challenging patients and athletes to promote neural plasticity, skilled performance, and recovery.
Collapse
Affiliation(s)
- Lasse Christiansen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark. .,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Amager and Hvidovre, Hvidovre, Denmark.
| | - Malte Nejst Larsen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Mads Just Madsen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Amager and Hvidovre, Hvidovre, Denmark
| | - Michael James Grey
- School of Health Sciences, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Jens Bo Nielsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Lundbye-Jensen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
18
|
D'Amico JM, Rouffet DM, Gandevia SC, Taylor JL. Unlike voluntary contractions, stimulated contractions of a hand muscle do not reduce voluntary activation or motoneuronal excitability. J Appl Physiol (1985) 2020; 128:1412-1422. [PMID: 32324475 DOI: 10.1152/japplphysiol.00553.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Voluntary force declines during sustained, maximal voluntary contractions (MVC) due to changes in muscle and central nervous system properties. Central fatigue, an exercise-induced reduction in voluntary activation, is influenced by multiple processes. Some may occur independently of descending voluntary drive. To differentiate the effects associated with voluntary drive from other central and peripheral influences, we measured voluntary activation and motoneuron excitability following fatiguing contractions produced voluntarily or by electrical stimulation. On two separate days, participants performed either a 2-min MVC of adductor pollicis muscle or received 2-min continuous supramaximal electrical stimulation of the ulnar nerve. In study 1 (n = 14), the superimposed twitch elicited by ulnar nerve stimulation during brief MVCs was increased, and, hence, voluntary activation was reduced, up to 240 s after the 2-min MVC [-20 ± 12% (SD), P = 0.002] but not the 2-min stimulated contraction (-4 ± 7%), despite large reductions in MVC force (voluntary, -54 ± 18%; stimulated, -46 ± 16%). In study 2 (n = 12), F-waves recorded from the adductor pollicis were reduced in area for 150 s following the 2-min MVC (-21 ± 16%, P = 0.007) but not after the stimulated contraction (5 ± 27%). Therefore, voluntary activation and motoneuron excitability decreased only when descending voluntary drive was present during the fatiguing task. The findings do not exclude a cortical or brain stem contribution to the reduced voluntary activation but suggest that neither sensory feedback from the fatigued muscle nor repetitive activation of motoneurons underlie the changes, whereas they are consistent with motoneuronal inhibition by released factors linked to voluntary drive.NEW & NOTEWORTHY We demonstrate that reductions in voluntary activation and motoneuron excitability following 2-min isometric maximal contractions in humans occur only when fatigue is produced through voluntary contractions and not through electrically stimulated contractions. This is contrary to studies that suggest that changes in the superimposed twitch and therefore voluntary activation are explained by changes in peripheral factors alone. Thus, the interpolated twitch technique remains a viable tool to assess voluntary activation and central fatigue.
Collapse
Affiliation(s)
- J M D'Amico
- Neuroscience Research Australia, Randwick, New South Wales, Australia.,Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville, Louisville, Kentucky
| | - D M Rouffet
- Kentucky Spinal Cord Injury Research Center, Department of Health and Sport Sciences, University of Louisville, Louisville, Kentucky.,Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - S C Gandevia
- Neuroscience Research Australia, Randwick, New South Wales, Australia.,University of New South Wales, Sydney, New South Wales, Australia
| | - J L Taylor
- Neuroscience Research Australia, Randwick, New South Wales, Australia.,School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia
| |
Collapse
|
19
|
Vastano R, Perez MA. Changes in motoneuron excitability during voluntary muscle activity in humans with spinal cord injury. J Neurophysiol 2020; 123:454-461. [PMID: 31461361 PMCID: PMC7052637 DOI: 10.1152/jn.00367.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/19/2019] [Accepted: 08/19/2019] [Indexed: 11/22/2022] Open
Abstract
The excitability of resting motoneurons increases following spinal cord injury (SCI). The extent to which motoneuron excitability changes during voluntary muscle activity in humans with SCI, however, remains poorly understood. To address this question, we measured F waves by using supramaximal electrical stimulation of the ulnar nerve at the wrist and cervicomedullary motor-evoked potentials (CMEPs) by using high-current electrical stimulation over the cervicomedullary junction in the first dorsal interosseous muscle at rest and during 5 and 30% of maximal voluntary contraction into index finger abduction in individuals with chronic cervical incomplete SCI and aged-matched control participants. We found higher persistence (number of F waves present in each set) and amplitude of F waves at rest in SCI compared with control participants. With increasing levels of voluntary contraction, the amplitude, but not the persistence, of F waves increased in both groups but to a lesser extent in SCI compared with control participants. Similarly, the CMEP amplitude increased in both groups but to a lesser extent in SCI compared with controls. These results were also found at matched absolutely levels of electromyographic activity, suggesting that these changes were not related to decreases in voluntary motor output after SCI. F-wave and CMEP amplitudes were positively correlated across conditions in both groups. These results support the hypothesis that the responsiveness of the motoneuron pool during voluntary activity decreases following SCI, which could alter the generation and strength of voluntary muscle contractions.NEW & NOTEWORTHY How the excitability of motoneurons changes during voluntary muscle activity in humans with spinal cord injury (SCI) remains poorly understood. We found that F-wave and cervicomedullary motor-evoked potential amplitude, outcomes reflecting motoneuronal excitability, increased during voluntary activity compared with rest in SCI participants but to a lesser extent that in controls. These results suggest that the responsiveness of motoneurons during voluntary activity decreases following SCI, which might affect functionally relevant plasticity after the injury.
Collapse
Affiliation(s)
- Roberta Vastano
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida
- Department of Neurological Surgery, University of Miami, Miami, Florida
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, Florida
| | - Monica A Perez
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida
- Department of Neurological Surgery, University of Miami, Miami, Florida
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, Florida
- Shirley Ryan Ability Laboratory, Northwestern University, Chicago, Illinois
- Hines Veterans Affairs Medical Center, Chicago, Illinois
| |
Collapse
|
20
|
Tankisi H, Burke D, Cui L, de Carvalho M, Kuwabara S, Nandedkar SD, Rutkove S, Stålberg E, van Putten MJAM, Fuglsang-Frederiksen A. Standards of instrumentation of EMG. Clin Neurophysiol 2019; 131:243-258. [PMID: 31761717 DOI: 10.1016/j.clinph.2019.07.025] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 07/12/2019] [Accepted: 07/14/2019] [Indexed: 12/14/2022]
Abstract
Standardization of Electromyography (EMG) instrumentation is of particular importance to ensure high quality recordings. This consensus report on "Standards of Instrumentation of EMG" is an update and extension of the earlier IFCN Guidelines published in 1999. First, a panel of experts in different fields from different geographical distributions was invited to submit a section on their particular interest and expertise. Then, the merged document was circulated for comments and edits until a consensus emerged. The first sections in this document cover technical aspects such as instrumentation, EMG hardware and software including amplifiers and filters, digital signal analysis and instrumentation settings. Other sections cover the topics such as temporary storage, trigger and delay line, averaging, electrode types, stimulation techniques for optimal and standardised EMG examinations, and the artefacts electromyographers may face and safety rules they should follow. Finally, storage of data and databases, report generators and external communication are summarized.
Collapse
Affiliation(s)
- Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital & Dept of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - David Burke
- Royal Prince Alfred Hospital and University of Sydney, Australia
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Mamede de Carvalho
- Faculdade de Medicina-iMM, Universidade de Lisboa, Lisbon, Portugal; Department of Neurosciences, Centro Hospitalar Universitário de Lisboa, Portugal
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Japan
| | | | | | - Erik Stålberg
- Department Clin Neurophysiology, Inst Neurosciences, Uppsala University, Sweden
| | | | - Anders Fuglsang-Frederiksen
- Department of Clinical Neurophysiology, Aarhus University Hospital & Dept of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
21
|
Wang ZL, Cui L, Liu M, Zhang K, Liu S, Ding Q. Split-Hand Syndrome in Amyotrophic Lateral Sclerosis: Differences in Dysfunction of the FDI and ADM Spinal Motoneurons. Front Neurosci 2019; 13:371. [PMID: 31133773 PMCID: PMC6517473 DOI: 10.3389/fnins.2019.00371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/01/2019] [Indexed: 12/11/2022] Open
Abstract
The F-wave test allows for the non-invasive assessment of spinal motoneuron excitability. We investigated the difference in spinal motoneuron dysfunction between the first dorsal interosseous (FDI) and abductor digit minimi (ADM) muscles by investigating F-waves and to assess the contribution of spinal mechanisms to split-hand syndrome in patients with amyotrophic lateral sclerosis (ALS). Sixty-five consecutive ALS patients and twenty age- and gender-matched healthy controls (HCs) were enrolled. Motor nerve conduction studies and F-waves were performed bilaterally on median and ulnar nerves in all subjects. HCs revealed prominently longer F-wave latencies, lower chronodispersion, mean F-wave amplitude, and mean and maximal F/M amplitude ratio (P < 0.001) in the FDI compared to the ADM. However, no significant differences in almost all F-wave parameters between the FDI and ADM were observed in ALS patients with affected hands except the minimal and mean F-wave latency. These data suggest that excitability is greatly changed in the spinal motoneurons innervating the FDI. Furthermore, the mean F-wave amplitude (r = 0.454, P = 0.002) of the FDI was significantly correlated with the FDI/ADM CMAP amplitude ratio in ALS patients with affected hands but not of the ADM. Our findings suggested that the dysfunction of spinal motoneurons between the FDI and ADM was different in ALS, and spinal motoneuron dysfunction was associated with development of the split-hand phenomenon.
Collapse
Affiliation(s)
- Zhi-Li Wang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Neurosciences Center, Chinese Academy of Medical Sciences, Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Kang Zhang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Shuangwu Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Qingyun Ding
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| |
Collapse
|
22
|
Temporal Profile and Limb-specificity of Phasic Pain-Evoked Changes in Motor Excitability. Neuroscience 2018; 386:240-255. [DOI: 10.1016/j.neuroscience.2018.06.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/20/2018] [Accepted: 06/24/2018] [Indexed: 12/17/2022]
|
23
|
Christiansen L, Perez MA. Targeted-Plasticity in the Corticospinal Tract After Human Spinal Cord Injury. Neurotherapeutics 2018; 15:618-627. [PMID: 29946981 PMCID: PMC6095776 DOI: 10.1007/s13311-018-0639-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Spinal cord injury (SCI) often results in impaired or absent sensorimotor function below the level of the lesion. Recent electrophysiological studies in humans with chronic incomplete SCI demonstrate that voluntary motor output can be to some extent potentiated by noninvasive stimulation that targets the corticospinal tract. We discuss emerging approaches that use transcranial magnetic stimulation (TMS) over the primary motor cortex and electrical stimulation over a peripheral nerve as tools to induce plasticity in residual corticospinal projections. A single TMS pulse over the primary motor cortex has been paired with peripheral nerve electrical stimulation at precise interstimulus intervals to reinforce corticospinal synaptic transmission using principles of spike-timing dependent plasticity. Pairs of TMS pulses have also been used at interstimulus intervals that mimic the periodicity of descending indirect (I) waves volleys in the corticospinal tract. This data, along with information about the extent of the injury, provides a new framework for exploring the contribution of the corticospinal tract to recovery of function following SCI.
Collapse
Affiliation(s)
- Lasse Christiansen
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami, Miami, FL, 33136, USA
- Bruce W. Carter Department of Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA
| | - Monica A Perez
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami, Miami, FL, 33136, USA.
- Bruce W. Carter Department of Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA.
| |
Collapse
|
24
|
Christiansen L, Urbin MA, Mitchell GS, Perez MA. Acute intermittent hypoxia enhances corticospinal synaptic plasticity in humans. eLife 2018; 7:e34304. [PMID: 29688171 PMCID: PMC5915172 DOI: 10.7554/elife.34304] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/12/2018] [Indexed: 01/02/2023] Open
Abstract
Acute intermittent hypoxia (AIH) enhances voluntary motor output in humans with central nervous system damage. The neural mechanisms contributing to these beneficial effects are unknown. We examined corticospinal function by evaluating motor evoked potentials (MEPs) elicited by cortical and subcortical stimulation of corticospinal axons and the activity in intracortical circuits in a finger muscle before and after 30 min of AIH or sham AIH. We found that the amplitude of cortically and subcortically elicited MEPs increased for 75 min after AIH but not sham AIH while intracortical activity remained unchanged. To examine further these subcortical effects, we assessed spike-timing dependent plasticity (STDP) targeting spinal synapses and the excitability of spinal motoneurons. Notably, AIH increased STDP outcomes while spinal motoneuron excitability remained unchanged. Our results provide the first evidence that AIH changes corticospinal function in humans, likely by altering corticospinal-motoneuronal synaptic transmission. AIH may represent a novel noninvasive approach for inducing spinal plasticity in humans.
Collapse
Affiliation(s)
- Lasse Christiansen
- Department of Neurological Surgery, The Miami Project to Cure ParalysisUniversity of MiamiMiamiUnited States
| | - MA Urbin
- Department of Neurological Surgery, The Miami Project to Cure ParalysisUniversity of MiamiMiamiUnited States
| | - Gordon S Mitchell
- Center for Respiratory Research and RehabilitationUniversity of FloridaGainesvilleUnited States
- Department of Physical TherapyUniversity of FloridaGainesvilleUnited States
- McKnight Brain InstituteUniversity of FloridaGainesvilleUnited States
| | - Monica A Perez
- Department of Neurological Surgery, The Miami Project to Cure ParalysisUniversity of MiamiMiamiUnited States
| |
Collapse
|
25
|
Kothari M, Stubbs PW, Pedersen AR, Jensen J, Nielsen JF. Reliability of surface electromyography measurements from the suprahyoid muscle complex. J Oral Rehabil 2017. [PMID: 28644567 DOI: 10.1111/joor.12537] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Assessment of swallowing musculature using motor evoked potentials (MEPs) can be used to evaluate neural pathways. However, recording of the swallowing musculature is often invasive, uncomfortable and unrealistic in normal clinical practice. To investigate the possibility of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Seventeen healthy participants were recruited. Measurements were performed twice with one week between sessions. Single-pulse (at 120% and 140% of the resting motor threshold (rMT)) and paired-pulse (2 ms and 15 ms paired pulse) transcranial magnetic stimulation (TMS) were used to elicit MEPs in the SMC which were recorded using sEMG. ≈50% of participants (range: 42-58%; depending on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single-pulse and paired-pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. The assessment of the SMC using sEMG following TMS was poorly reliable for ≈50% of participants. Although using sEMG to assess swallowing musculature function is easier to perform clinically and more comfortable to patients than invasive measures, as the measurement of muscle activity using TMS is unreliable, the use of sEMG for this muscle group is not recommended and requires further research and development.
Collapse
Affiliation(s)
- M Kothari
- Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Hammel, Denmark
| | - P W Stubbs
- Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Hammel, Denmark
| | - A R Pedersen
- Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Hammel, Denmark
| | - J Jensen
- Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Hammel, Denmark
| | - J F Nielsen
- Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Hammel, Denmark
| |
Collapse
|
26
|
Lewis MJ, Howard JF, Olby NJ. The Relationship between Trans-Lesional Conduction, Motor Neuron Pool Excitability, and Motor Function in Dogs with Incomplete Recovery from Severe Spinal Cord Injury. J Neurotrauma 2017; 34:2994-3002. [PMID: 28462632 DOI: 10.1089/neu.2017.5012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Spontaneous, acute, complete thoracolumbar spinal cord injury (TL-SCI) in dogs frequently results in permanent deficits modeling chronic paralysis in people. Recovery of walking without recovery of sensation has been interpreted in dogs as reflexive spinal walking. To evaluate this assumption, this study characterized the electrophysiological status of motor and sensory long tracts and local reflex circuitry in dogs with absent recovery of sensation after acute TL-SCI and correlated findings to gait scores. Twenty dogs with permanent deficits after acute, clinically complete TL-SCI and 6 normal dogs were prospectively enrolled. Transcranial magnetic motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), H-reflex, and F-waves were evaluated. Gait was quantified using an ordinal, open field scale (OFS) and treadmill-based stepping and coordination scores (SS, RI). MEP latency and H-reflex variables were compared between cases and controls. Associations between presence of MEPs, SSEPs, F-waves or H-reflex variables, and gait scores were determined. Pelvic limb MEPs were detected in 4 cases; no case had trans-lesional sensory conduction. Latency was longer and conduction velocity slower in cases than controls (pa = 0.0064, 0.0023, respectively). Three of 4 cases with pelvic limb MEPs were ambulatory, and gait scores (OFS, SS, RI) were each associated with presence of trans-lesional conduction (pa = 0.006, 0.006, 0.003, respectively). H threshold in cases (mean, 3.2mA ±2.5) was lower than controls (mean, 7.9mA ±3.1; pa = 0.011) and was inversely associated with treadmill-based scores, SS, and RI (pa = 0.042, 0.043, respectively). The association between pelvic limb MEPs and gait scores supports the importance of descending influence on regaining walking after severe TL-SCI in dogs rather than just activation of spinal walking. The inverse association between H-reflex threshold and gait scores implies that increases in motor neuron pool excitability might also contribute to motor recovery.
Collapse
Affiliation(s)
- Melissa J Lewis
- 1 Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.,2 Comparative Medicine Institute, North Carolina State University , Raleigh, North Carolina
| | - James F Howard
- 3 Department of Neurology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
| | - Natasha J Olby
- 1 Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.,2 Comparative Medicine Institute, North Carolina State University , Raleigh, North Carolina
| |
Collapse
|
27
|
Carroll TJ, Taylor JL, Gandevia SC. Recovery of central and peripheral neuromuscular fatigue after exercise. J Appl Physiol (1985) 2017; 122:1068-1076. [DOI: 10.1152/japplphysiol.00775.2016] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 12/29/2022] Open
Abstract
Sustained physical exercise leads to a reduced capacity to produce voluntary force that typically outlasts the exercise bout. This “fatigue” can be due both to impaired muscle function, termed “peripheral fatigue,” and a reduction in the capacity of the central nervous system to activate muscles, termed “central fatigue.” In this review we consider the factors that determine the recovery of voluntary force generating capacity after various types of exercise. After brief, high-intensity exercise there is typically a rapid restitution of force that is due to recovery of central fatigue (typically within 2 min) and aspects of peripheral fatigue associated with excitation-contraction coupling and reperfusion of muscles (typically within 3–5 min). Complete recovery of muscle function may be incomplete for some hours, however, due to prolonged impairment in intracellular Ca2+ release or sensitivity. After low-intensity exercise of long duration, voluntary force typically shows rapid, partial, recovery within the first few minutes, due largely to recovery of the central, neural component. However, the ability to voluntarily activate muscles may not recover completely within 30 min after exercise. Recovery of peripheral fatigue contributes comparatively little to the fast initial force restitution and is typically incomplete for at least 20–30 min. Work remains to identify what factors underlie the prolonged central fatigue that usually accompanies long-duration single joint and locomotor exercise and to document how the time course of neuromuscular recovery is affected by exercise intensity and duration in locomotor exercise. Such information could be useful to enhance rehabilitation and sports performance.
Collapse
Affiliation(s)
- T. J. Carroll
- Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, University of Queensland; and
| | - J. L. Taylor
- Neuroscience Research Australia and University of New South Wales
| | - S. C. Gandevia
- Neuroscience Research Australia and University of New South Wales
| |
Collapse
|
28
|
Pelletier R, Higgins J, Bourbonnais D. The relationship of corticospinal excitability with pain, motor performance and disability in subjects with chronic wrist/hand pain. J Electromyogr Kinesiol 2017; 34:65-71. [PMID: 28411487 DOI: 10.1016/j.jelekin.2017.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 03/25/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022] Open
Abstract
There is a growing body of evidence of changes in corticospinal excitability associated with musculoskeletal disorders, however there is a lack of knowledge of how these changes relate to measures of pain, motor performance and disability. An exploratory study was performed utilizing Transcranial Magnetic Stimulation to investigate differences in corticospinal excitability in the Abductor Pollicis Brevis (APB) between 15 pain-free subjects and 15 subjects with chronic wrist/hand pain and to determine how corticospinal excitability was associated with measures of pain (visual analog scale, AUSCAN™), hand motor performance (isometric and key pinch strength, Purdue Pegboard Test), disability (AUSCAN™), and spinal motoneuronal excitability. Input-output curves demonstrated increased corticospinal excitability of the APB in the affected hand of subjects with chronic pain (p<0.01). Changes in corticospinal excitability were significantly correlated with pain intensity (r=0.77), disability (r=0.58), and negatively correlated with motoneuronal excitability (r=-0.57). Corticospinal excitability in subjects with heterogeneous injuries of the wrist/hand was associated with disability and pain.
Collapse
Affiliation(s)
- René Pelletier
- Sciences de la réadaptation, École de réadaptation, Faculté de Médecine, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
| | - Johanne Higgins
- École de réadaptation, Faculté de médecine, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal (CRIR), Canada.
| | - Daniel Bourbonnais
- École de réadaptation, Faculté de médecine, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal (CRIR), Canada.
| |
Collapse
|
29
|
Ginanneschi F, Mondelli M, Aretini A, Rossi A. Reappraisal of the F/M amplitude ratio in carpal tunnel syndrome. FUNCTIONAL NEUROLOGY 2017; 32:23-27. [PMID: 28380320 DOI: 10.11138/fneur/2017.32.1.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The F-wave/M-wave amplitude (F/M-amp) ratio has been shown to be increased in peripheral neuropathies, provided the maximum M-wave is relatively preserved. Reduced M-wave amplitudes and central facilitation of antidromically-induced reactivation of the anterior horn cells' axon hillocks (F-wave) are believed to contribute to higher F/M-amp ratios. The present study was undertaken to re-evaluate mechanisms responsible for higher F/M-amp ratios in carpal tunnel syndrome (CTS). We enrolled 232 cases affected by CTS and 108 controls. Fand M-wave amplitudes and F-wave chronodispersion were analyzed for the median and ulnar nerves. The F/M-amp ratio of the median nerve in CTS subjects with moderate-severe nerve damage was significantly higher than that of mild CTS subjects and controls. Chronodispersion of the median nerve F-wave increased with increasing CTS severity. We conclude that the relative preservation of the median nerve F-wave is due to damage to the large diameter muscle afferent fibers responsible for the monosynaptic response. Absence of the monosynaptic response makes the small motoneurons, usually inaccessible to the antidromic volley because of its collision with the orthodromic reflex volley, able to fire in the F-wave.
Collapse
|
30
|
Mayo M, DeForest BA, Castellanos M, Thomas CK. Characterization of Involuntary Contractions after Spinal Cord Injury Reveals Associations between Physiological and Self-Reported Measures of Spasticity. Front Integr Neurosci 2017; 11:2. [PMID: 28232792 PMCID: PMC5299008 DOI: 10.3389/fnint.2017.00002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/16/2017] [Indexed: 12/02/2022] Open
Abstract
Correlations between physiological, clinical and self-reported assessments of spasticity are often weak. Our aims were to quantify functional, self-reported and physiological indices of spasticity in individuals with thoracic spinal cord injury (SCI; 3 women, 9 men; 19–52 years), and to compare the strength and direction of associations between these measures. The functional measure we introduced involved recording involuntary electromyographic activity during a transfer from wheelchair to bed which is a daily task necessary for function. High soleus (SL) and tibialis anterior (TA) F-wave/M-wave area ratios were the only physiological measures that distinguished injured participants from the uninjured (6 women, 13 men, 19–67 years). Hyporeflexia (decreased SL H/M ratio) was unexpectedly present in older participants after injury. During transfers, the duration and intensity of involuntary electromyographic activity varied across muscles and participants, but coactivity was common. Wide inter-participant variability was seen for self-reported spasm frequency, severity, pain and interference with function, as well as tone (resistance to imposed joint movement). Our recordings of involuntary electromyographic activity during transfers provided evidence of significant associations between physiological and self-reported measures of spasticity. Reduced low frequency H-reflex depression in SL and high F-wave/M-wave area ratios in TA, physiological indicators of reduced inhibition and greater motoneuron excitability, respectively, were associated with long duration SL and biceps femoris (BF) electromyographic activity during transfers. In turn, participants reported high spasm frequency when transfers involved short duration TA EMG, decreased co-activation between SL and TA, as well as between rectus femoris (RF) vs. BF. Thus, the duration of muscle activity and/or the time of agonist-antagonist muscle coactivity may be used by injured individuals to count spasms. Intense electromyographic activity and high tone related closely (possibly from joint stabilization), while intense electromyographic activity in one muscle of an agonist-antagonist pair (especially in TA vs. SL, and RF vs. BF) likely induced joint movement and was associated with severe spasms. These data support the idea that individuals with SCI describe their spasticity by both the duration and intensity of involuntary agonist-antagonist muscle coactivity during everyday tasks.
Collapse
Affiliation(s)
- Meagan Mayo
- The Miami Project to Cure Paralysis, University of Miami Miami, FL, USA
| | | | | | - Christine K Thomas
- The Miami Project to Cure Paralysis, University of MiamiMiami, FL, USA; Department of Neurological Surgery, University of MiamiMiami, FL, USA; Department of Physiology and Biophysics, University of MiamiMiami, FL, USA
| |
Collapse
|
31
|
Thomas CK, Häger CK, Klein CS. Increases in human motoneuron excitability after cervical spinal cord injury depend on the level of injury. J Neurophysiol 2016; 117:684-691. [PMID: 27852734 DOI: 10.1152/jn.00676.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/11/2016] [Indexed: 11/22/2022] Open
Abstract
After human spinal cord injury (SCI), motoneuron recruitment and firing rate during voluntary and involuntary contractions may be altered by changes in motoneuron excitability. Our aim was to compare F waves in single thenar motor units paralyzed by cervical SCI to those in uninjured controls because at the single-unit level F waves primarily reflect the intrinsic properties of the motoneuron and its initial segment. With intraneural motor axon stimulation, F waves were evident in all 4 participants with C4-level SCI, absent in 8 with C5 or C6 injury, and present in 6 of 12 Uninjured participants (P < 0.001). The percentage of units that generated F waves differed across groups (C4: 30%, C5 or C6: 0%, Uninjured: 16%; P < 0.001). Mean (±SD) proximal axon conduction velocity was slower after C4 SCI [64 ± 4 m/s (n = 6 units), Uninjured: 73 ± 8 m/s (n = 7 units); P = 0.037]. Mean distal axon conduction velocity differed by group [C4: 40 ± 8 m/s (n = 20 units), C5 or C6: 49 ± 9 m/s (n = 28), Uninjured: 60 ± 7 m/s (n = 45); P < 0.001]. Motor unit properties (EMG amplitude, twitch force) only differed after SCI (P ≤ 0.004), not by injury level. Motor units with F waves had distal conduction velocities, M-wave amplitudes, and twitch forces that spanned the respective group range, indicating that units with heterogeneous properties produced F waves. Recording unitary F waves has shown that thenar motoneurons closer to the SCI (C5 or C6) have reduced excitability whereas those further away (C4) have increased excitability, which may exacerbate muscle spasms. This difference in motoneuron excitability may be related to the extent of membrane depolarization following SCI. NEW & NOTEWORTHY Unitary F waves were common in paralyzed thenar muscles of people who had a chronic spinal cord injury (SCI) at the C4 level compared with uninjured people, but F waves did not occur in people that had SCI at the C5 or C6 level. These results highlight that intrinsic motoneuron excitability depends, in part, on how close the motoneurons are to the site of the spinal injury, which could alter the generation and strength of voluntary and involuntary muscle contractions.
Collapse
Affiliation(s)
- Christine K Thomas
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida;
| | - Charlotte K Häger
- Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden; and
| | - Cliff S Klein
- Guangdong Work Injury Rehabilitation Center, Guangzhou, People's Republic of China
| |
Collapse
|
32
|
Gandevia SC, Khan SL, Taylor JL. Reply from S. C. Gandevia, S. L. Khan and J. L. Taylor. J Physiol 2016; 594:3847-8. [PMID: 27365162 DOI: 10.1113/jp272663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- S C Gandevia
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, 2031, Australia.
| | - S L Khan
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, 2031, Australia
| | - J L Taylor
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, 2031, Australia
| |
Collapse
|
33
|
Balbi P. Limitations of the F-wave test in monitoring spinal motoneurone excitability. J Physiol 2016; 594:3845. [PMID: 27365161 DOI: 10.1113/jp272442] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 03/17/2016] [Indexed: 11/08/2022] Open
Affiliation(s)
- Pietro Balbi
- Department of Neurorehabilitation, 'Salvatore Maugeri' Foundation, Scientific Institute of Pavia, IRCCS, via Boezio 28, Pavia, Italy.
| |
Collapse
|
34
|
Khan SI, Taylor JL, Gandevia SC. Unexpected factors affecting the excitability of human motoneurones in voluntary and stimulated contractions. J Physiol 2016; 594:2707-17. [PMID: 26940402 DOI: 10.1113/jp272164] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/25/2016] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS The output of human motoneurone pools decreases with fatiguing exercise, but the mechanisms involved are uncertain. We explored depression of recurrent motoneurone discharges (F-waves) after sustained maximal voluntary contractions (MVCs). MVC depressed the size and frequency of F-waves in a hand muscle but a submaximal contraction (at 50% MVC) did not. Surprisingly, activation of the motoneurones antidromically by stimulation of the ulnar nerve (at 20 or 40 Hz) did not depress F-wave area or persistence. Furthermore, a sustained (3 min) MVC of a hand muscle depressed F-waves in its antagonist but not in a remote hand muscle. Our findings suggest that depression of F-waves after voluntary contractions is not simply due to repetitive activation of the motoneurones but requires descending voluntary drive. Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools. ABSTRACT There are major spinal changes induced by repetitive activity and fatigue that could contribute to 'central' fatigue but the mechanisms involved are poorly understood in humans. Here we confirmed that the recurrent motoneuronal discharge (F-wave) is reduced during relaxation immediately after a sustained maximal voluntary contraction (MVC) of an intrinsic hand muscle (abductor digiti minimi, ADM) and explored the relationship between motoneurone firing and the depression of F-waves in three ways. First, the depression (in both F-wave area and F-wave persistence) was present after a 10 s MVC (initial decrease 36.4 ± 19.1%; mean ± SD) but not after a submaximal voluntary contraction at 50% maximum. Second, to evoke motoneurone discharge without volitional effort, 10 s tetanic contractions were produced by supramaximal ulnar nerve stimulation at the elbow at physiological frequencies of 25 and 40 Hz. Surprisingly, neither produced depression of F-waves in ADM to test supramaximal stimulation of the ulnar nerve at the wrist. Finally, a sustained MVC (3 min) of the antagonist to ADM (4th palmar interosseous) depressed F-waves in the anatomically close ADM (20 ± 18.2%) but not in the more remote first dorsal interosseous on the radial side of the hand. We argue that depression of F-waves after voluntary contractions may not be due to repetitive activation of the motoneurones but requires descending voluntary drive. Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools and it reveals potentially novel mechanisms controlling the output of human motoneurones.
Collapse
Affiliation(s)
- Serajul I Khan
- Neuroscience Research Australia and University of New South Wales, Randwick, NSW, Australia
| | - Janet L Taylor
- Neuroscience Research Australia and University of New South Wales, Randwick, NSW, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia and University of New South Wales, Randwick, NSW, Australia
| |
Collapse
|
35
|
Burke D. Clinical uses of H reflexes of upper and lower limb muscles. Clin Neurophysiol Pract 2016; 1:9-17. [PMID: 30214954 PMCID: PMC6123946 DOI: 10.1016/j.cnp.2016.02.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/10/2016] [Indexed: 10/25/2022] Open
Abstract
H reflexes can be recorded from virtually all muscles that have muscle spindles, but reflex reinforcement may be required for the reflex response to be demonstrable. This can allow conduction across proximal nerve segments and most nerve root segments commonly involved by pathology. Stimulus rate is critical in subjects who are at rest. However the reflex attenuation with higher rates is greatly reduced during a background contraction of the test muscle, with only minor changes in latency if any. In addition the contraction ensures that the reflex response occurs in the desired muscle. Reflex latencies should be corrected for height (or limb length) and age. Because the reflex discharge requires a synchronised volley in group Ia afferents, large increases in reflex latency occur rarely with purely sensory lesions. If the H reflex of soleus, quadriceps femoris or flexor carpi radialis is absent at rest but appears during a voluntary contraction at near-normal latency, there is either low central excitability or a predominantly sensory abnormality. With the former H reflexes will be difficult to elicit throughout the body. If H reflexes can be recorded at rest from muscles for which no reflex can normally be demonstrated, there is good evidence for hyperreflexia. In the context of possible ALS, this is an important finding when there is EMG evidence of chronic partial denervation in that muscle.
Collapse
|
36
|
Semerdjieva N, Atanasova D, Hranov G, Milanov I. F-Wave in the Upper Extremities of Patients with Primary Torsion Dystonia. NEUROPHYSIOLOGY+ 2015. [DOI: 10.1007/s11062-015-9528-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
37
|
Jerath NU, Aul E, Reddy CG, Azadeh H, Swenson A, Kimura J. Prolongation of F-wave minimal latency: a sensitive predictor of polyneuropathy. Int J Neurosci 2015; 126:520-525. [PMID: 26000925 DOI: 10.3109/00207454.2015.1040492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION To evaluate the sensitivity of F-wave minimal latencies, we compared F-waves with motor and sensory nerve conduction studies (MNCS and SNCS) in patients with peripheral neuropathy. METHODS A retrospective chart review conducted in 484 patients confirmed the clinical evidence of a polyneuropathy, and studies of F-wave minimal latencies as well as MNCS and SNCS in each patient. RESULTS Overall rate of abnormality reached 469/484 (96.9%) for F-wave minimal latencies as compared to 374/484 (77%) for nerve conduction studies ( p < 0.0001). Nerve-specific abnormalities of F-waves showed 290/354 (82%), 140/171 (82%), 367/398 (92%) and 357/376 (95%) for median, ulnar, peroneal and tibial nerves, respectively. Corresponding values for MNCS consisted of 108/354 (31%), 29/171 (17%), 258/398 (65%) and 189/376 (50%) (all p < 0.0001). In contrast, SNCS revealed abnormalities in 120/333 (36%), 60/159 (38%) and 266/474 (56%) of median, ulnar and sural nerves. CONCLUSION F-wave minimal latencies serve as the best predictor of polyneuropathy followed by SNCS and then MNCS.
Collapse
Affiliation(s)
- Nivedita Uberoi Jerath
- a Department of Neurology , Carver College of Medicine, The University of Iowa , Iowa City , IA , USA.,b Iowa City Veterans Affair Medical Center , Iowa City , IA , USA
| | - Edward Aul
- a Department of Neurology , Carver College of Medicine, The University of Iowa , Iowa City , IA , USA.,b Iowa City Veterans Affair Medical Center , Iowa City , IA , USA
| | - Chandan G Reddy
- c Department of Neurosurgery , The University of Iowa , Iowa City , IA , USA
| | - Hamid Azadeh
- d Department of Physiotherapy, School of Rehabilitation Sciences , Isfahan University of Medical Sciences , Isfahan , Iran
| | - Andrea Swenson
- a Department of Neurology , Carver College of Medicine, The University of Iowa , Iowa City , IA , USA.,b Iowa City Veterans Affair Medical Center , Iowa City , IA , USA
| | - Jun Kimura
- a Department of Neurology , Carver College of Medicine, The University of Iowa , Iowa City , IA , USA
| |
Collapse
|
38
|
Takemi M, Masakado Y, Liu M, Ushiba J. Is event-related desynchronization a biomarker representing corticospinal excitability? ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:281-4. [PMID: 24109679 DOI: 10.1109/embc.2013.6609492] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Brain computer interfaces (BCIs) using event-related desynchronization (ERD) of the electroencephalogram (EEG), which is believed to represent increased activation of the sensorimotor cortex, have attracted attention as tools for rehabilitation of upper limb motor functions in hemiplegic stroke patients. However, it remains unclear whether the corticospinal excitability is actually correlated with ERD. The purpose of this study was to assess the association between the ERD magnitude and the excitability of primary motor cortex (M1) and spinal motoneurons. M1 excitability was tested by motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) using transcranial magnetic stimulation, and spinal motoneuronal excitability was tested by F-waves using peripheral nerve stimulation. Results showed that large ERD during motor imagery was associated with significantly increased F-wave persistence and reduced SICI, but no significant changes in ICF and the response average of F-wave amplitudes. Our findings suggest that ERD magnitude during motor imagery represents the instantaneous excitability of both M1 and spinal motoneurons. This study provides electrophysiological evidence that ERD-based BCI with motor imagery task increases corticospinal excitability as changes accompanying actual movements.
Collapse
|
39
|
Fang J, Cui LY, Liu MS, Guan YZ, Li XG, Cui B, Ding QY. F Wave Study in Amyotrophic Lateral Sclerosis: Assessment of Segmental Motoneuronal Dysfunction. Chin Med J (Engl) 2015; 128:1738-42. [PMID: 26112713 PMCID: PMC4733717 DOI: 10.4103/0366-6999.159346] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: Dysfunctional spinal circuit may play a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). The purpose of this study was to use F waves for assessment of segmental motoneuronal excitability following upper motor neuron (UMN) dysfunctions in ALS. Methods: We studied the F waves of 152 ulnar nerves recorded from abductor digiti minimi in 82 patients with ALS. Two groups of hands were defined based on the presence or absence of pyramidal signs in the same upper limb. The group with pyramidal signs in the upper limbs was designated as the P group, and the group without pyramidal signs in the upper limbs was designated as the NP group. Results: The mean (P < 0.001), median (P < 0.001) and maximum (P = 0.035) F wave amplitudes, mean (P < 0.001), median (P < 0.001) and maximum (P = 0.003) F/M amplitude ratio, index repeating neuron (P < 0.001) and index repeater F waves (P < 0.001) of the P group were significantly increased compared with the NP group. No significant differences were identified for F wave chronodispersion (P = 0.628), mean F wave latency (P = 0.151), minimum F wave latency (P = 0.211), maximum F wave latency (P = 0.199), F wave persistence (P = 0.738), F wave duration (P = 0.152), F wave conduction velocity (P = 0.813) and number of giant F waves (P = 0.072) between the two groups. Conclusions: In this study, increased F wave amplitude, F/M amplitude ratio and number of repeater F waves reflected enhanced segmental motoneuronal excitability following UMN dysfunctions in ALS.
Collapse
Affiliation(s)
| | - Li-Ying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
We recently showed that subcortical circuits contribute to control the gain of motor cortical inputs to spinal motoneurons during precision grip of a small object. Here, we examine whether the involvement of the motor cortex could be revealed by grasping with different hand postures. Using noninvasive cortical, cervicomedullary, and peripheral nerve stimulation we examined in humans motor-evoked potentials (MEPs) and the activity in intracortical circuits (suppression of voluntary electromyography) and spinal motoneurons (F-waves) in intrinsic hand muscles when grasping a 6 mm cylinder with the index finger and thumb while the hand was held in the neutral position or during full pronation and supination. We demonstrate that the size of cortically evoked MEPs in the first dorsal interosseous, but not in the abductor pollicis brevis and abductor digit minimi muscles, was reduced to a similar extent during grasping with the hand pronated or supinated compared with the neutral position. Notably, the suppression of MEPs was present from the MEP onset, suggesting that indirect corticospinal pathways were less likely to be involved than direct connections. There was less intracortical inhibition targeting the first dorsal interosseous during hand pronation and supination compared with neutral and this negatively correlated with changes in MEP size. In contrast, cervicomedullary MEPs and F-waves remained unchanged across conditions, as did MEPs evoked during unopposed weak flexion of the index finger. Our findings reveal a distinct influence of the posture of the hand on the activity of cortical pathways controlling different hand muscles during grasping.
Collapse
|
41
|
Sensorimotor event-related desynchronization represents the excitability of human spinal motoneurons. Neuroscience 2015; 297:58-67. [PMID: 25839147 DOI: 10.1016/j.neuroscience.2015.03.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/06/2015] [Accepted: 03/19/2015] [Indexed: 11/22/2022]
Abstract
Amplitudes of mu and beta (7-26Hz) oscillations measured by electroencephalography over the sensorimotor areas are suppressed during motor imagery as well as during voluntary movements. This phenomenon is referred to as event-related desynchronization (ERD) and is known to reflect motor cortical excitability. The increased motor cortical excitability associated with ERD during hand motor imagery would induce a descending cortical volley to spinal motoneurons, resulting in facilitation of spinal motoneuronal excitability. Therefore, in the present study, we tested the association of ERD during motor imagery with the excitability of spinal motoneurons in 15 healthy participants. Spinal excitability was tested using the F-wave recorded from the right abductor pollicis brevis muscle. The F-wave results from antidromic activation of spinal motoneurons and is induced by peripheral nerve stimulation. Participants performed 5s of motor imagery of right thumb abduction following 7s of rest. The right median nerve was stimulated at wrist level when the ERD magnitude of the contralateral hand sensorimotor area exceeded predetermined thresholds during motor imagery. The results showed ERD magnitude during hand motor imagery was associated with an increase in F-wave persistence, but not with the response average of F-wave amplitude or F-wave latency. These findings suggest that the ERD magnitude may be a biomarker representing increases in the excitability of both cortical and spinal levels.
Collapse
|
42
|
Kirimoto H, Tamaki H, Suzuki M, Matsumoto T, Sugawara K, Kojima S, Onishi H. Sensorimotor modulation differs with load type during constant finger force or position. PLoS One 2014; 9:e108058. [PMID: 25233353 PMCID: PMC4169486 DOI: 10.1371/journal.pone.0108058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/23/2014] [Indexed: 11/19/2022] Open
Abstract
During submaximal isometric contraction, there are two different load types: production of a constant force against a rigid restraint (force task), and maintenance of position against a constant load (position task). Previous studies reported that the time to task failure during a fatigue task was twice as long in the force task compared with the position task. Sensory feedback processing may contribute to these differences. The purpose of the current study was to determine the influence of load types during static muscle contraction tasks on the gating effect, i.e., attenuation of somatosensory-evoked potentials (SEPs) and the cortical silent period (cSP). Ten healthy subjects contracted their right first dorsal interosseus muscle by abducting their index finger for 90 s, to produce a constant force against a rigid restraint that was 20% of the maximum voluntary contraction (force task), or to maintain a constant position with 10° abduction of the metacarpophalangeal joint against the same load (position task). Somatosensory evoked potentials (SEPs) were recorded from C3' by stimulating either the right ulnar or median nerve at the wrist while maintaining contraction. The cortical silent period (cSP) was also elicited by transcranial magnetic stimulation. Reduction of the amplitude of the P45 component of SEPs was significantly larger during the position task than during the force task and under control rest conditions when the ulnar nerve, but not the median nerve, was stimulated. The position task had a significantly shorter cSP duration than the force task. These results suggest the need for more proprioceptive information during the position task than the force task. The shorter duration of the cSP during the position task may be attributable to larger amplitude of heteronymous short latency reflexes. Sensorimotor modulations may differ with load type during constant finger force or position tasks.
Collapse
Affiliation(s)
- Hikari Kirimoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hiroyuki Tamaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Makoto Suzuki
- School of Allied Health Sciences, Kitasato University, Kanagawa, Japan
| | - Takuya Matsumoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
- Graduate School of Health and Welfare, Niigata University of Health and Welfare, Niigata, Japan
| | - Kazuhiro Sugawara
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Syo Kojima
- Graduate School of Health and Welfare, Niigata University of Health and Welfare, Niigata, Japan
- Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| |
Collapse
|
43
|
Fisher MA. F-waves in diabetes mellitus: Answers and questions. Muscle Nerve 2014; 49:783-5. [DOI: 10.1002/mus.24101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 10/13/2013] [Accepted: 10/15/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Morris A. Fisher
- Department of Neurology (127); Hines VAH, Hines, Illinois and Loyola University Chicago Stritch School of Medicine; Maywood Illinois USA
| |
Collapse
|
44
|
Pan H, Jian F, Lin J, Chen N, Zhang C, Zhang Z, Ding Z, Wang Y, Cui L, Kimura J. F-wave latencies in patients with diabetes mellitus. Muscle Nerve 2014; 49:804-8. [PMID: 24259350 DOI: 10.1002/mus.24127] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 11/04/2013] [Accepted: 11/14/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Hua Pan
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Fan Jian
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Jinxi Lin
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Na Chen
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Chunfang Zhang
- Department of Endocrinology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Zaiqiang Zhang
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Zeyu Ding
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Yongjun Wang
- Department of Neurology; Beijing Tiantan Hospital, Capital Medical University; Beijing 100050 China
| | - Liying Cui
- Department of Neurology; Peking Union Medical College Hospital, Chinese Academy of Medical Science; Beijing 100730 China
| | - Jun Kimura
- Division of Clinical Electrophysiology; Department of Neurology; College of Medicine, University of Iowa; Iowa City IA, USA
| |
Collapse
|
45
|
Burke D. Inability of F waves to control for changes in the excitability of the motoneurone pool in motor control studies. Clin Neurophysiol 2013; 125:221-2. [PMID: 24144781 DOI: 10.1016/j.clinph.2013.09.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 09/27/2013] [Indexed: 10/26/2022]
Affiliation(s)
- David Burke
- Department of Neurology, Royal Prince Alfred Hospital, The University of Sydney, Sydney, NSW 2006, Australia.
| |
Collapse
|
46
|
Modelling recurrent discharge in the spinal α-motoneuron: reappraisal of the F wave. Clin Neurophysiol 2013; 125:427-9. [PMID: 24269615 DOI: 10.1016/j.clinph.2013.09.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 08/28/2013] [Accepted: 09/22/2013] [Indexed: 11/20/2022]
|
47
|
Derosiere G, Billot M, Ward ET, Perrey S. Adaptations of Motor Neural Structures' Activity to Lapses in Attention. Cereb Cortex 2013; 25:66-74. [DOI: 10.1093/cercor/bht206] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
48
|
McNeil CJ, Butler JE, Taylor JL, Gandevia SC. Testing the excitability of human motoneurons. Front Hum Neurosci 2013; 7:152. [PMID: 23630483 PMCID: PMC3633937 DOI: 10.3389/fnhum.2013.00152] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 04/06/2013] [Indexed: 12/03/2022] Open
Abstract
The responsiveness of the human central nervous system can change profoundly with exercise, injury, disuse, or disease. Changes occur at both cortical and spinal levels but in most cases excitability of the motoneuron pool must be assessed to localize accurately the site of adaptation. Hence, it is critical to understand, and employ correctly, the methods to test motoneuron excitability in humans. Several techniques exist and each has its advantages and disadvantages. This review examines the most common techniques that use evoked compound muscle action potentials to test the excitability of the motoneuron pool and describes the merits and limitations of each. The techniques discussed are the H-reflex, F-wave, tendon jerk, V-wave, cervicomedullary motor evoked potential (CMEP), and motor evoked potential (MEP). A number of limitations with these techniques are presented.
Collapse
Affiliation(s)
- Chris J McNeil
- Neuroscience Research Australia Randwick, NSW, Australia ; School of Health and Exercise Sciences, University of British Columbia Kelowna, BC, Canada
| | | | | | | |
Collapse
|
49
|
Magalhães FH, de Toledo DR, Kohn AF. Plantar flexion force induced by amplitude-modulated tendon vibration and associated soleus V/F-waves as an evidence of a centrally-mediated mechanism contributing to extra torque generation in humans. J Neuroeng Rehabil 2013; 10:32. [PMID: 23531240 PMCID: PMC3621298 DOI: 10.1186/1743-0003-10-32] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 02/28/2013] [Indexed: 11/23/2022] Open
Abstract
Background High-frequency trains of electrical stimulation applied over the human muscles can generate forces higher than would be expected by direct activation of motor axons, as evidenced by an unexpected relation between the stimuli and the evoked contractions, originating what has been called “extra forces”. This phenomenon has been thought to reflect nonlinear input/output neural properties such as plateau potential activation in motoneurons. However, more recent evidence has indicated that extra forces generated during electrical stimulation are mediated primarily, if not exclusively, by an intrinsic muscle property, and not from a central mechanism as previously thought. Given the inherent differences between electrical and vibratory stimuli, this study aimed to investigate: (a) whether the generation of vibration-induced muscle forces results in an unexpected relation between the stimuli and the evoked contractions (i.e. extra forces generation) and (b) whether these extra forces are accompanied by signs of a centrally-mediated mechanism or whether intrinsic muscle properties are the predominant mechanisms. Methods Six subjects had their Achilles tendon stimulated by 100 Hz vibratory stimuli that linearly increased in amplitude (with a peak-to-peak displacement varying from 0 to 5 mm) for 10 seconds and then linearly decreased to zero for the next 10 seconds. As a measure of motoneuron excitability taken at different times during the vibratory stimulation, short-latency compound muscle action potentials (V/F-waves) were recorded in the soleus muscle in response to supramaximal nerve stimulation. Results Plantar flexion torque and soleus V/F-wave amplitudes were increased in the second half of the stimulation in comparison with the first half. Conclusion The present findings provide evidence that vibratory stimuli may trigger a centrally-mediated mechanism that contributes to the generation of extra torques. The vibration-induced increased motoneuron excitability (leading to increased torque generation) presumably activates spinal motoneurons following the size principle, which is a desirable feature for stimulation paradigms involved in rehabilitation programs and exercise training.
Collapse
Affiliation(s)
- Fernando Henrique Magalhães
- Neuroscience Program and Biomedical Engineering Laboratory, Universidade de São Paulo, EPUSP, Avenida Professor Luciano Gualberto, Travessa 3, n,158, São Paulo, SP, Brazil.
| | | | | |
Collapse
|
50
|
Gruet M, Temesi J, Rupp T, Levy P, Millet G, Verges S. Stimulation of the motor cortex and corticospinal tract to assess human muscle fatigue. Neuroscience 2013; 231:384-99. [DOI: 10.1016/j.neuroscience.2012.10.058] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/10/2012] [Accepted: 10/29/2012] [Indexed: 10/27/2022]
|