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Vucic S, de Carvalho M, Bashford J, Alix JJP. Contribution of neurophysiology to the diagnosis and monitoring of ALS. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 176:87-118. [PMID: 38802184 DOI: 10.1016/bs.irn.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
This chapter describes the role of neurophysiological techniques in diagnosing and monitoring amyotrophic lateral sclerosis (ALS). Despite many advances, electromyography (EMG) remains a keystone investigation from which to build support for a diagnosis of ALS, demonstrating the pathophysiological processes of motor unit hyperexcitability, denervation and reinnervation. We consider development of the different diagnostic criteria and the role of EMG therein. While not formally recognised by established diagnostic criteria, we discuss the pioneering studies that have demonstrated the diagnostic potential of transcranial magnetic stimulation (TMS) of the motor cortex and highlight the growing evidence for TMS in the diagnostic process. Finally, accurately monitoring disease progression is crucial for the successful implementation of clinical trials. Neurophysiological measures of disease state have been incorporated into clinical trials for over 20 years and we review prominent techniques for assessing disease progression.
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Affiliation(s)
- Steve Vucic
- Brain and Nerve Research Centre, Concord Clinical School and Department of Neurology, Concord Repatriation General Hospital, The University of Sydney, Sydney, NSW, Australia
| | - Mamede de Carvalho
- Instituto de Medicina Molecular João Lobo Antunes, Centro de Estudos Egas Moniz, Faculty of Medicine, Universidade de Lisboa, Lisboa, Portugal; Department of Neurosciences, CHULN, Centro Académico de Medicina de Lisboa, Lisboa, Portugal
| | - James Bashford
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - James J P Alix
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom.
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Higashihara M, Yamazaki H, Izumi Y, Kobayashi M, Nodera H, Oishi C, Iwata A, Murayama S, Kaji R, Sonoo M. Far-field potential of the compound muscle action potential as a reliable marker in amyotrophic lateral sclerosis. Muscle Nerve 2023; 68:257-263. [PMID: 37086196 DOI: 10.1002/mus.27829] [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: 09/04/2022] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/23/2023]
Abstract
INTRODUCTION/AIMS Reliable neurophysiological markers in amyotrophic lateral sclerosis (ALS) are of great interest. The compound muscle action potential (CMAP) amplitude has been a conventional marker, although it is greatly influenced by the electrode position. We propose the far-field potential of the CMAP (FFP-CMAP) as a new neurophysiological marker in ALS. METHODS Patients with ALS and age-matched healthy controls were enrolled. We used a proximal reference (pref) in addition to the conventional distal reference (dref). Routine CMAP was recorded from the belly-dref lead and FFP-CMAP from the dref-pref lead for the ulnar and tibial nerves. Multiple point stimulation motor unit number estimation (MUNE) was also examined in the ulnar nerve. Inter-rater reproducibility was evaluated by two examiners, and some patients were followed up every 3 mo for 1 y. RESULTS We tested 17 patients with ALS and 10 controls. The amplitudes of routine CMAP and FFP-CMAP in the ulnar and tibial nerves, and hypothenar MUNE value in the ulnar nerve were significantly decreased in ALS compared to controls. Ulnar FFP-CMAP achieved the highest inter-rater intraclass correlation coefficient (ICC) value (0.942) when compared with routine CMAP (0.880) and MUNE (0.839). The tibial FFP-CMAP had a higher ICC value (0.986) than the routine CMAP (0.697). In this way, the FFP-CMAP showed high inter-rater reproducibility because its shape was not much influenced by the electrode position. During 1-y follow-up, decline of CMAP, FFP, and MUNE showed significant correlations with the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R). DISCUSSION The FFP-CMAP shows promise as a reliable marker for ALS.
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Affiliation(s)
- Mana Higashihara
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Hiroki Yamazaki
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Yuishin Izumi
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | | | - Hiroyuki Nodera
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
- Department of Neurology, Tenri Hospital, Tenri, Japan
| | - Chizuko Oishi
- Department of Neurology, Kyorin University Hospital, Mitaka, Japan
| | - Atsushi Iwata
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Shigeo Murayama
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Ryuji Kaji
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
- Department of Neurology, Utano National Hospital, Kyoto, Japan
| | - Masahiro Sonoo
- Department of Neurology, Teikyo University School of Medicine, Tokyo, Japan
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Mandeville R, Sanchez B, Johnston B, Bazarek S, Thum JA, Birmingham A, See RHB, Leochico CFD, Kumar V, Dowlatshahi AS, Brown J, Stashuk D, Rutkove SB. A scoping review of current and emerging techniques for evaluation of peripheral nerve health, degeneration, and regeneration: part 1, neurophysiology. J Neural Eng 2023; 20:041001. [PMID: 37279730 DOI: 10.1088/1741-2552/acdbeb] [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: 01/18/2023] [Accepted: 06/06/2023] [Indexed: 06/08/2023]
Abstract
Peripheral neuroregeneration research and therapeutic options are expanding exponentially. With this expansion comes an increasing need to reliably evaluate and quantify nerve health. Valid and responsive measures that can serve as biomarkers of the nerve status are essential for both clinical and research purposes for diagnosis, longitudinal follow-up, and monitoring the impact of any intervention. Furthermore, such biomarkers can elucidate regeneration mechanisms and open new avenues for research. Without these measures, clinical decision-making falls short, and research becomes more costly, time-consuming, and sometimes infeasible. As a companion to Part 2, which is focused on non-invasive imaging, Part 1 of this two-part scoping review systematically identifies and critically examines many current and emerging neurophysiological techniques that have the potential to evaluate peripheral nerve health, particularly from the perspective of regenerative therapies and research.
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Affiliation(s)
- Ross Mandeville
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
| | - Benjamin Sanchez
- Department Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, United States of America
| | - Benjamin Johnston
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA 02115, United States of America
| | - Stanley Bazarek
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA 02115, United States of America
| | - Jasmine A Thum
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Austin Birmingham
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Reiner Henson B See
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Carl Froilan D Leochico
- Department of Physical Medicine and Rehabilitation, St. Luke's Medical Center, Global City, Taguig, The Philippines
- Department of Rehabilitation Medicine, Philippine General Hospital, University of the Philippines Manila, Manila, The Philippines
| | - Viksit Kumar
- Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Arriyan S Dowlatshahi
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
| | - Justin Brown
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Daniel Stashuk
- Department of Systems Design Engineering, University of Waterloo, Ontario N2L 3G1, Canada
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
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Sørensen DM, Bostock H, Abrahao A, Alaamel A, Alaydin HC, Ballegaard M, Boran E, Cengiz B, de Carvalho M, Dunker Ø, Fuglsang-Frederiksen A, Graffe CC, Jones KE, Kallio M, Kalra S, Krarup C, Krøigård T, Liguori R, Lupescu T, Maitland S, Matamala JM, Moldovan M, Moreno-Roco J, Nilsen KB, Phung L, Santos MO, Themistocleous AC, Uysal H, Vacchiano V, Whittaker RG, Zinman L, Tankisi H. Estimating motor unit numbers from a CMAP scan: Repeatability study on three muscles at 15 centres. Clin Neurophysiol 2023; 151:92-99. [PMID: 37236129 DOI: 10.1016/j.clinph.2023.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/16/2023] [Accepted: 04/15/2023] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To assess the repeatability and suitability for multicentre studies of MScanFit motor unit number estimation (MUNE), which involves modelling compound muscle action potential (CMAP) scans. METHODS Fifteen groups in 9 countries recorded CMAP scans twice, 1-2 weeks apart in healthy subjects from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. The original MScanFit program (MScanFit-1) was compared with a revised version (MScanFit-2), designed to accommodate different muscles and recording conditions by setting the minimal motor unit size as a function of maximum CMAP. RESULTS Complete sets of 6 recordings were obtained from 148 subjects. CMAP amplitudes differed significantly between centres for all muscles, and the same was true for MScanFit-1 MUNE. With MScanFit-2, MUNE differed less between centres but remained significantly different for APB. Coefficients of variation between repeats were 18.0% for ADM, 16.8% for APB, and 12.1% for TA. CONCLUSIONS It is recommended for multicentre studies to use MScanFit-2 for analysis. TA provided the least variable MUNE values between subjects and the most repeatable within subjects. SIGNIFICANCE MScanFit was primarily devised to model the discontinuities in CMAP scans in patients and is less suitable for healthy subjects with smooth scans.
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Affiliation(s)
- D M Sørensen
- Department of Clinical Neurophysiology, Aarhus University Hospital, Denmark
| | - H Bostock
- UCL Queen Square Institute of Neurology, Queen Square, London, United Kingdom
| | - A Abrahao
- Department of Medicine, University of Toronto, Toronto, Canada
| | - A Alaamel
- Department of Neurology, Akdeniz University Hospital, Antalya, Turkey
| | - H C Alaydin
- Department of Neurology, Gazi University, Ankara, Turkey
| | - M Ballegaard
- Department of Clinical Neurology, Zealand University Hospital, Roskilde, Denmark
| | - E Boran
- Department of Neurology, Gazi University, Ankara, Turkey
| | - B Cengiz
- Department of Neurology, Gazi University, Ankara, Turkey
| | - M de Carvalho
- Faculty of Medicine, iMM, Centro de Estudos Egas Moniz, Universidade de Lisboa, Department of Neurosciences and Mental Health, CHULN, Lisbon, Portugal
| | - Ø Dunker
- Department of Neurology and Department of Research and Innovation, Division of Clinical Neuroscience, Oslo University Hospital, Norway
| | - A Fuglsang-Frederiksen
- Department of Clinical Neurophysiology, Aarhus University Hospital, Denmark; Department of Clinical Institute, Aarhus University, Aarhus, Denmark
| | - C C Graffe
- Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark
| | - K E Jones
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - M Kallio
- Department of Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - S Kalra
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - C Krarup
- Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark
| | - T Krøigård
- Department of Neurology, Odense University Hospital, Denmark
| | - R Liguori
- Dipertimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - T Lupescu
- Department of Neurology, Agrippa Ionescu Hospital, Bucharest, Romania
| | - S Maitland
- Translational and Clinical Research Institute, Newcastle University, United Kingdom
| | - J M Matamala
- Translational Neurology and Neurophysiology Lab, Department of Neurological Sciences and Biomedical Neuroscience Institute, University of Chile, Santiago, Chile
| | - M Moldovan
- Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark
| | - J Moreno-Roco
- Translational Neurology and Neurophysiology Lab, Department of Neurological Sciences and Biomedical Neuroscience Institute, University of Chile, Santiago, Chile
| | - K B Nilsen
- Department of Neurology and Department of Research and Innovation, Division of Clinical Neuroscience, Oslo University Hospital, Norway
| | - L Phung
- Department of Medicine, University of Toronto, Toronto, Canada
| | - M O Santos
- Faculty of Medicine, iMM, Centro de Estudos Egas Moniz, Universidade de Lisboa, Department of Neurosciences and Mental Health, CHULN, Lisbon, Portugal
| | - A C Themistocleous
- Nuffield Department of Clinical Neurosciences University of Oxford, Oxford, United Kingdom
| | - H Uysal
- Department of Medicine, University of Toronto, Toronto, Canada
| | - V Vacchiano
- Dipertimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - R G Whittaker
- Translational and Clinical Research Institute, Newcastle University, United Kingdom
| | - L Zinman
- UCL Queen Square Institute of Neurology, Queen Square, London, United Kingdom
| | - H Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Denmark; Department of Clinical Institute, Aarhus University, Aarhus, Denmark.
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Chen M, Lu Z, Zong Y, Li X, Zhou P. A Novel Analysis of Compound Muscle Action Potential Scan: Staircase Function Fitting and StairFit Motor Unit Number Estimation. IEEE J Biomed Health Inform 2023; PP:1579-1587. [PMID: 37015542 PMCID: PMC10032645 DOI: 10.1109/jbhi.2022.3229211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Compound muscle action potential (CMAP) scan provides a detailed stimulus-response curve for examination of neuromuscular disease. The objective of the study is to develop a novel CMAP scan analysis to extract motor unit number estimation (MUNE) and other physiological or diagnostic information. A staircase function was used as the basic mathematical model of the CMAP scan. An optimal staircase function fitting model was estimated for each given number of motor units, and the fitting model with the minimum number of motor units that meets a predefined error requirement was accepted. This yields MUNE as well as the spike amplitude and activation threshold of each motor unit that contributes to the CMAP scan. The significance of the staircase function fit was confirmed using simulated CMAP scans with different motor unit number (20, 50, 100 and 150) and baseline noise (1 µV, 5 µV and 10 µV) inputs, in terms of MUNE performance, repeatability, and the test-retest reliability. For experimental data, the average MUNE of the first dorsal interosseous muscle derived from the staircase function fitting was 57.5 ± 26.9 for the tested spinal cord injury subjects, which was significantly lower than 101.2 ± 16.9, derived from the control group (p < 0.001). The staircase function fitting provides an appropriate approach to CMAP scan processing, yielding MUNE and other useful parameters for examination of motor unit loss and muscle fiber reinnervation.
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Affiliation(s)
- Maoqi Chen
- School of Rehabilitation Science and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong 266072, China
| | - Zhiyuan Lu
- School of Rehabilitation Science and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong 266072, China
| | - Ya Zong
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaoyan Li
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI 53226 USA; Fischell Department of Bioengineering, University of Maryland at College Park, College Park, MD 20742 USA
| | - Ping Zhou
- School of Rehabilitation Science and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong 266072, China
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Yeoh S, Warner WS, Bromberg M, Mahan MA. Retrograde labeling correlates with motor unit number estimation in rapid-stretch nerve injury. Muscle Nerve 2023; 67:169-176. [PMID: 36420650 DOI: 10.1002/mus.27756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 11/15/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022]
Abstract
INTRODUCTION/AIMS Rapid-stretch nerve injuries represent a substantial treatment challenge. No study has examined motor neuron connection after rapid-stretch injury. Our objective in this study was to characterize the electrophysiological properties of graded rapid-stretch nerve injury and assess motor neuron health using retrograde labeling and muscle adenosine triphosphatase (ATPase) histology. METHODS Male C57BL/6 mice (n = 6 per group) were rapid-stretch injured at four levels of severity: sham injury, stretch within elastic modulus, inelastic deformation, and stretch rupture. Serial compound muscle action potential (CMAP) and motor unit number estimation (MUNE) measurements were made for 48 days, followed by retrograde labeling and muscle ATPase histology. RESULTS Elastic injuries showed no durable abnormalities. Inelastic injury demonstrated profound initial reduction in CMAP and MUNE (P < .036) on day 2, with partial recovery by day 14 after injury (CMAP: 40% baseline, P = .003; MUNE: 55% baseline, P = .033). However, at the experimental endpoint, CMAP had recovered to baseline with only limited improvement in MUNE. Inelastic injury led to reduced retrograde-labeled neurons and grouped fiber type histology. Rupture injury had severe and nonrecovering electrophysiological impairment, dramatically reducing labeled neurons (P = .005), and atrophic or type 1 muscle fibers. There was an excellent correlation between MUNE and retrograde-labeled tibial motor neurons across injury severities (R2 = 0.96). DISCUSSION There was no significant electrophysiological derangement in low-severity injuries but there was recoverable conduction block in inelastic injury with slow recovery, potentially due to collateral sprouting. Rupture injuries yielded permanent failure of injured axons to reinnervate. These results provide insight into the pathophysiology of clinical injuries and recovery.
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Affiliation(s)
- Stewart Yeoh
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah
| | - Wesley S Warner
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah
| | - Mark Bromberg
- Department of Neurology, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah
| | - Mark A Mahan
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah
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Zhou P. Appropriate index parameters may serve a useful purpose in motor unit number estimation. Clin Neurophysiol 2022; 139:117-118. [PMID: 35577679 DOI: 10.1016/j.clinph.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 05/03/2022] [Indexed: 11/03/2022]
Affiliation(s)
- Ping Zhou
- Biomedical and Rehabilitation Engineering Program, University of Health and Rehabilitation Sciences, Qingdao, Shandong, China.
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Abstract
The purpose of our review was to compare the distribution of motor unit properties across human muscles of different sizes and recruitment ranges. Although motor units can be distinguished based on several different attributes, we focused on four key parameters that have a significant influence on the force produced by muscle during voluntary contractions: the number of motor units, average innervation number, the distributions of contractile characteristics, and discharge rates within motor unit pools. Despite relatively few publications on this topic, current data indicate that the most influential factor in the distribution of these motor unit properties between muscles is innervation number. Nonetheless, despite a fivefold difference in innervation number between a hand muscle (first dorsal interosseus) and a lower leg muscle (tibialis anterior), the general organization of their motor unit pools, and the range of discharge rates appear to be relatively similar. These observations provide foundational knowledge for studies on the control of movement and the changes that occur with aging and neurological disorders.
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Affiliation(s)
- Jacques Duchateau
- Laboratory of Applied Biology and Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado
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Chan Y, Alix JJP, Neuwirth C, Barkhaus PE, Castro J, Jenkins TM, McDermott CJ, Shaw PJ, de Carvalho M, Nandedkar S, Stålberg E, Weber M. Reinnervation as measured by the motor unit size index is associated with preservation of muscle strength in amyotrophic lateral sclerosis, but not all muscles reinnervate. Muscle Nerve 2021; 65:203-210. [PMID: 34687220 DOI: 10.1002/mus.27444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 11/11/2022]
Abstract
INTRODUCTION/AIMS The motor unit size index (MUSIX) may provide insight into reinnervation patterns in diseases such as amyotrophic lateral sclerosis (ALS). However, it is not known whether MUSIX detects clinically relevant changes in reinnervation, or if all muscles manifest changes in MUSIX in response to reinnervation after motor unit loss. METHODS Fifty-seven patients with ALS were assessed at 3-month intervals for 12 months in four centers. Muscles examined were abductor pollicis brevis, abductor digiti minimi, biceps brachii, and tibialis anterior. Results were split into two groups: muscles with increases in MUSIX and those without increases. Longitudinal changes in MUSIX, motor unit number index (MUNIX), compound muscle action potential amplitude, and Medical Research Council strength score were investigated. RESULTS One hundred thirty-three muscles were examined. Fifty-nine percent of the muscles exhibited an increase in MUSIX during the study. Muscles with MUSIX increases lost more motor units (58% decline in MUNIX at 12 months, P < .001) than muscles that did not increase MUSIX (34.6% decline in MUNIX at 12 months, P < .001). However, longitudinal changes in muscle strength were similar. When motor unit loss was similar, the absence of a MUSIX increase was associated with a significantly greater loss of muscle strength (P = .002). DISCUSSION MUSIX increases are associated with greater motor unit loss but relative preservation of muscle strength. Thus, MUSIX appears to be measuring a clinically relevant response that can provide a quantitative outcome measure of reinnervation in clinical trials. Furthermore, MUSIX suggests that reinnervation may play a major role in determining the progression of weakness.
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Affiliation(s)
- Young Chan
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - James J P Alix
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Christoph Neuwirth
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital, St. Gallen, Switzerland
| | | | - José Castro
- Department of Neurosciences, Centro Hospitalar Lisboa Norte-Hospital de Santa Maria, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisboa, Portugal
| | - Thomas M Jenkins
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Mamede de Carvalho
- Department of Neurosciences, Centro Hospitalar Lisboa Norte-Hospital de Santa Maria, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisboa, Portugal
| | | | - Erik Stålberg
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden
| | - Markus Weber
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital, St. Gallen, Switzerland
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Wilcox M, Gregory H, Powell R, Quick TJ, Phillips JB. Strategies for Peripheral Nerve Repair. CURRENT TISSUE MICROENVIRONMENT REPORTS 2020; 1:49-59. [PMID: 33381765 PMCID: PMC7749870 DOI: 10.1007/s43152-020-00002-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW This review focuses on biomechanical and cellular considerations required for development of biomaterials and engineered tissues suitable for implantation following PNI, as well as translational requirements relating to outcome measurements for testing success in patients. RECENT FINDINGS Therapies that incorporate multiple aspects of the regenerative environment are likely to be key to improving therapies for nerve regeneration. This represents a complex challenge when considering the diversity of biological, chemical and mechanical factors involved. In addition, clinical outcome measures following peripheral nerve repair which are sensitive and responsive to changes in the tissue microenvironment following neural injury and regeneration are required. SUMMARY Effective new therapies for the treatment of PNI are likely to include engineered tissues and biomaterials able to evoke a tissue microenvironment that incorporates both biochemical and mechanical features supportive to regeneration. Translational development of these technologies towards clinical use in humans drives a concomitant need for improved clinical measures to quantify nerve regeneration.
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Affiliation(s)
- Matthew Wilcox
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX UK
- UCL Centre for Nerve Engineering, University College London, London, UK
- Peripheral Nerve Injury Research Unit, Royal National Orthopaedic Hospital, Stanmore, UK
| | - Holly Gregory
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX UK
- UCL Centre for Nerve Engineering, University College London, London, UK
| | - Rebecca Powell
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX UK
- UCL Centre for Nerve Engineering, University College London, London, UK
| | - Tom J. Quick
- Peripheral Nerve Injury Research Unit, Royal National Orthopaedic Hospital, Stanmore, UK
| | - James B. Phillips
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX UK
- UCL Centre for Nerve Engineering, University College London, London, UK
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Taylor SA, Sherlock C, Ridall G, Fearnhead P. Motor unit number estimation via sequential Monte Carlo. Comput Stat Data Anal 2020. [DOI: 10.1016/j.csda.2019.106845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Geijo-Barrientos E, Pastore-Olmedo C, De Mingo P, Blanquer M, Gómez Espuch J, Iniesta F, Iniesta NG, García-Hernández A, Martín-Estefanía C, Barrios L, Moraleda JM, Martínez S. Intramuscular Injection of Bone Marrow Stem Cells in Amyotrophic Lateral Sclerosis Patients: A Randomized Clinical Trial. Front Neurosci 2020; 14:195. [PMID: 32265627 PMCID: PMC7105864 DOI: 10.3389/fnins.2020.00195] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/24/2020] [Indexed: 12/11/2022] Open
Abstract
Background Preclinical studies suggest that stem cells may be a valuable therapeutic tool in amyotrophic lateral sclerosis (ALS). As it has been demonstrated that there are molecular changes at the end-plate during the early stages of motorneuron degeneration in animal models, we hypothesize that the local effect of this stem cell delivery method could slow the progressive loss of motor units (MUs) in ALS patients. Methods We designed a Phase I/II clinical trial to study the safety of intramuscularly implanting autologous bone marrow mononuclear cells (BMMCs), including stem cells, in ALS patients and their possible effects on the MU of the tibialis anterior (TA) muscle. Twenty-two patients participated in a randomized, double-blind, placebo-controlled trial that consisted of a baseline visit followed by one intramuscular injection of BMNCs, follow-up visits at 30, 90, 180, and 360 days, and an additional year of clinical follow-up. In each patient, one TA muscle was injected with a single dose of BMMCs while the contralateral muscle was given a placebo; the sides were selected randomly. All visits included a complete EMG study of both TA muscles. Results Our results show that (1) the intramuscular injection of BMMCs is a safe procedure; (2) ALS patients show heterogeneities in the degree of TA injury; (3) a comparison of placebo-injected muscles with BMMC-injected muscles showed significant differences in only one parameter, the D50 index used to quantify the Compound Muscle Action Potential (CMAP) scan curve. This parameter was higher in the BMMC-injected TA muscle at both 90 days (placebo side: 29.55 ± 2.89, n = 20; experimental side: 39.25 ± 3.21, n = 20; p < 0.01) and 180 days (placebo side: 29.35 ± 3.29, n = 17; experimental side: 41.24 ± 3.34, n = 17; p < 0.01). Conclusion This procedure had no effect on the TA muscle MU properties, with the exception of the D50 index. Finding differences in just this index supports the fact that it may be much more sensitive than other electrophysiological parameters when studying treatment effects. Given the low number of patients and their heterogeneity, these results justify exploring the efficacy of this procedure in further patients and other muscles, through Phase II trials. Clinical Trial Registration www.clinicaltrials.gov (identifier NCT02286011); EudraCT number 2011-004801-25.
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Affiliation(s)
| | - Carlos Pastore-Olmedo
- Institute of Neurosciences, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Clinical Neurophysiology Service, San Juan University Hospital, Alicante, Spain
| | - Pedro De Mingo
- Service of Clinical Neurophysiology, Virgen de la Arrixaca University Clinical Hospital, Murcia, Spain
| | - Miguel Blanquer
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
| | - Joaquín Gómez Espuch
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Francisca Iniesta
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
| | - Natalia García Iniesta
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
| | - Ana García-Hernández
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
| | | | - Laura Barrios
- Department of Applied Statistics, SGAI-CSIC, Madrid, Spain
| | - José M Moraleda
- Hematopoietic Stem Cell Transplant and Cell Therapy Unit, Hematology Service, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
| | - Salvador Martínez
- Institute of Neurosciences, Universidad Miguel Hernández-CSIC, Alicante, Spain.,Institute for Bio-Health Research of Murcia (IMIB-Arrixaca), Murcia, Spain
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14
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Riancho J, Gil-Bea FJ, Santurtun A, López de Munaín A. Amyotrophic lateral sclerosis: a complex syndrome that needs an integrated research approach. Neural Regen Res 2019; 14:193-196. [PMID: 30530996 PMCID: PMC6301158 DOI: 10.4103/1673-5374.244783] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis, the most common neurodegenerative disease affecting motor neurons, lacks an effective treatment. A small fraction of amyotrophic lateral sclerosis cases have a familial origin, related to mutations in causative genes, while the vast majority of amyotrophic lateral sclerosis cases are considered to be sporadic, resulting from the interaction between genes and environmental factors in predisposed individuals. During the past few years, dozens of drugs have been postulated as promising strategies for the disease after showing some beneficial effects in preclinical cellular and murine models. However, the translation into clinical practice has been largely unsuccessful and the compounds failed when were tested in clinical trials. This might be explained, at least partially, by the enormous complexity of the disease both from clinico-epidemiological and a pathogenic points of view. In this review, we will briefly comment on the complexity of the disease focusing on some recent findings, and we will suggest how amyotrophic lateral sclerosis research might be reoriented to foster the advance in the diagnostic and therapeutic questions.
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Affiliation(s)
- Javier Riancho
- Service of Neurology, Hospital Sierrallana-Idival, Torrelavega; CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), Madrid, Spain
| | - Francisco J Gil-Bea
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), Madrid; Neurosciences Area, Institute Biodonostia, San Sebastián, Spain
| | - Ana Santurtun
- Department of Physiology and Pharmacology, University of Cantabria-Idival, Santander, Spain
| | - Adolfo López de Munaín
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), Madrid; Neurosciences Area, Institute Biodonostia; Department of Neurology, University Hospital Donostia, San Sebastián, Spain; Department of Neurosciences, University of the Basque Country, Universidad País Vasco-Euskal Herria Unibertsitatea, San Sebastián, Spain
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15
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Hachisuka A, Ming Chan K. A modified multiple point stimulation method for motor unit number estimation of the hypothenar muscles. Muscle Nerve 2018; 59:337-341. [PMID: 30488459 DOI: 10.1002/mus.26391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The goal of this study is to test the hypothesis that single motor unit action potentials (SMUPs) originating from other ulnar nerve-innervated intrinsic hand muscles can inflate the motor unit number estimation (MUNE) of the hypothenar muscles. METHODS Using the multiple point stimulation method, SMUPs recorded over the hypothenar muscles from distant origins were characterized through multichannel recordings. The MUNE calculated using only the hypothenar SMUPs was compared with estimations based on the whole ensemble. RESULTS Of the 41 studies performed, distant SMUPs represented 17 ± 9.5% (mean ± SD) of the overall sample. MUNE calculated using only hypothenar SMUPs was 423 ± 204, compared with 537 ± 290 if all SMUPs were included (P < 0.05). The extent of increase in MUNE was highly correlated with the proportion of distant SMUPs found (r = 0.89, P < 0.05). DISCUSSION Erroneous inclusion of SMUPs from distant muscles can significantly distort the MUNE results. Muscle Nerve 59:337-341, 2019.
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Affiliation(s)
- Akiko Hachisuka
- Division of Physical Medicine and Rehabilitation, University of Alberta, 5005 Katz Group Centre, Edmonton, Alberta, T6G 2E1, Canada.,Department of Rehabilitation Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - K Ming Chan
- Division of Physical Medicine and Rehabilitation, University of Alberta, 5005 Katz Group Centre, Edmonton, Alberta, T6G 2E1, Canada.,Division of Plastic Surgery, University of Alberta, Edmonton, Alberta, Canada
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16
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Fatehi F, Grapperon AM, Fathi D, Delmont E, Attarian S. The utility of motor unit number index: A systematic review. Neurophysiol Clin 2018; 48:251-259. [PMID: 30287192 DOI: 10.1016/j.neucli.2018.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 09/04/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022] Open
Abstract
The need for a valid biomarker for assessing disease progression and for use in clinical trials on amyotrophic lateral sclerosis (ALS) has stimulated the study of methods that could measure the number of motor units. Motor unit number index (MUNIX) is a newly developed neurophysiological technique that was demonstrated to have a good correlation with the number of motor units in a given muscle, even though it does not necessarily accurately express the actual number of viable motor neurons. Several studies demonstrated the technique is reproducible and capable of following motor neuron loss in patients with ALS and peripheral polyneuropathies. The main goal of this review was to conduct an extensive review of the literature using MUNIX. We conducted a systematic search in English medical literature published in two databases (PubMed and SCOPUS). In this review, we aimed to answer the following queries: Comparison of MUNIX with other MUNE techniques; the reproducibility of MUNIX; the utility of MUNIX in ALS and preclinical muscles, peripheral neuropathies, and other neurological disorders.
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Affiliation(s)
- Farzad Fatehi
- Reference Center for Neuromuscular Diseases and ALS, Timone University Hospital, 13385 Marseille, France; Department of Neurology, Iranian Center of Neurological Research, Neuroscience Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Aude-Marie Grapperon
- Reference Center for Neuromuscular Diseases and ALS, Timone University Hospital, 13385 Marseille, France
| | - Davood Fathi
- Department of Neurology, Iranian Center of Neurological Research, Neuroscience Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran; Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Emilien Delmont
- Reference Center for Neuromuscular Diseases and ALS, Timone University Hospital, 13385 Marseille, France
| | - Shahram Attarian
- Reference Center for Neuromuscular Diseases and ALS, Timone University Hospital, 13385 Marseille, France; Inserm, GMGF, Aix-Marseille University, Marseille, 13385 France.
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17
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Higashihara M, Menon P, van den Bos M, Geevasinga N, Vucic S. Reproducibility of motor unit number index and multiple point stimulation motor unit number estimation in controls. Muscle Nerve 2018; 58:660-664. [PMID: 30194855 DOI: 10.1002/mus.26339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2018] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Reproducibility of the multiple point stimulation motor unit number estimation (MPS-MUNE) technique was compared with the recently developed motor unit number index (MUNIX) technique. METHODS MPS-MUNE and MUNIX were performed on 15 healthy subjects at 3 different time-points by the same examiner. Reproducibility was analyzed using intraclass correlation coefficient (ICC) and coefficient of variation (CV). RESULTS ICC values for MUNIX and MPS-MUNE were excellent across 3 tests (0.80 and 0.77, respectively), although CV values were significantly lower for MUNIX than MPS-MUNE (P < 0.01). In addition, test-retest reproducibility was better for MUNIX, a finding largely attributable to poor reproducibility of the single motor unit action potential area. MUNIX (R = -0.48, P < 0.05) and MPS-MUNE (R = -0.53, P < 0.05) were significantly correlated with age. DISCUSSION MUNIX demonstrated better intrarater reproducibility and may be a more reliable neurophysiological biomarker than MPS-MUNE. Muscle Nerve 58: 660-664, 2018.
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Affiliation(s)
- Mana Higashihara
- Department of Neurology, Westmead Hospital, Sydney, New South Wales, Australia
| | - Parvathi Menon
- Westmead Clinical School, Cnr. Hawkesbury and Darcy Road, University of Sydney, New South Wales, 2145, Australia
| | - Mehdi van den Bos
- Westmead Clinical School, Cnr. Hawkesbury and Darcy Road, University of Sydney, New South Wales, 2145, Australia
| | - Nimeshan Geevasinga
- Westmead Clinical School, Cnr. Hawkesbury and Darcy Road, University of Sydney, New South Wales, 2145, Australia
| | - Steve Vucic
- Westmead Clinical School, Cnr. Hawkesbury and Darcy Road, University of Sydney, New South Wales, 2145, Australia
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18
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de Carvalho M, Barkhaus PE, Nandedkar SD, Swash M. Motor unit number estimation (MUNE): Where are we now? Clin Neurophysiol 2018; 129:1507-1516. [DOI: 10.1016/j.clinph.2018.04.748] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/31/2018] [Accepted: 04/29/2018] [Indexed: 12/13/2022]
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Nakano T, Kurimoto S, Kato S, Asano K, Hirata T, Kiyama H, Hirata H. Complete adult neurogenesis within a Wallerian degenerating nerve expressed as an ectopic ganglion. J Tissue Eng Regen Med 2018; 12:1469-1480. [DOI: 10.1002/term.2679] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 01/10/2018] [Accepted: 04/16/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Tomonori Nakano
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
| | - Shigeru Kurimoto
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
| | - Shuichi Kato
- Department of Orthopaedic Surgery; Konan Kosei Hospital; Konan Aichi Japan
| | - Kenichi Asano
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
| | - Takuma Hirata
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
| | - Hiroshi Kiyama
- Department of Functional Anatomy and Neuroscience; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
| | - Hitoshi Hirata
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Nagoya Aichi Japan
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20
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Togawa G, Saito M, Watanabe R. Assessment of the F wave technique for motor unit number estimation in normal dogs. Vet J 2018; 234:30-35. [PMID: 29680390 DOI: 10.1016/j.tvjl.2018.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 11/27/2022]
Abstract
Motor unit number estimation (MUNE) is an electrophysiological technique to quantify the number of motor units in a muscle. A previous study examining MUNE in dogs used an incremental method. The purpose of this study was to examine the use of the F wave method in dogs and to provide information about this technique. Seven healthy laboratory dogs were examined using the F wave method by stimulating either a single site or multiple sites. In the multiple site stimulation F wave (MSS-F) method, the nerve was stimulated at several close sites along the deep peroneal nerve innervating the extensor digitorum brevis muscle. Test-retest was performed with a 1 week interval in all dogs using both techniques. In this preliminary study, median MUNE values were 88 (range 27-187) using the single site stimulation F wave (SSS-F) method and 68.5 (range 47-106) using the MSS-F method. The intra-class correlation coefficients between the two sets of data for each method were 0.20 and 0.09 for left and right SSS-F, respectively, and 0.77 and 0.69 for left and right MSS-F, respectively. MSS-F had less intra-individual variability of MUNE values and was more reproducible. These results indicate that MSS-F can be performed in dogs. MUNE using MSS-F might help with quantitative evaluation of motor neurone dysfunction and progression of diseases affecting motor neurones.
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Affiliation(s)
- G Togawa
- Department of Surgery II, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - M Saito
- Department of Surgery II, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - R Watanabe
- Department of Surgery II, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
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21
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Piasecki M, Ireland A, Piasecki J, Stashuk DW, Swiecicka A, Rutter MK, Jones DA, McPhee JS. Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men. J Physiol 2018. [PMID: 29527694 PMCID: PMC5924831 DOI: 10.1113/jp275520] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Key points The age‐related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques. We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men. These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men.
Abstract Sarcopenia results from the progressive loss of skeletal muscle mass and reduced function in older age. It is likely to be associated with the well‐documented reduction of motor unit numbers innervating limb muscles and the increase in size of surviving motor units via reinnervation of denervated fibres. However, no evidence exists to confirm the extent of motor unit remodelling in sarcopenic individuals. The aim of the present study was to compare motor unit size and number between young (n = 48), non‐sarcopenic old (n = 13), pre‐sarcopenic (n = 53) and sarcopenic (n = 29) men. Motor unit potentials (MUPs) were isolated from intramuscular and surface EMG recordings. The motor unit numbers were reduced in all groups of old compared with young men (all P < 0.001). MUPs were higher in non‐sarcopenic and pre‐sarcopenic men compared with young men (P = 0.039 and 0.001 respectively), but not in the vastus lateralis of sarcopenic old (P = 0.485). The results suggest that extensive motor unit remodelling occurs relatively early during ageing, exceeds the loss of muscle mass and precedes sarcopenia. Reinnervation of denervated muscle fibres probably expands the motor unit size in the non‐sarcopenic and pre‐sarcopenic old, but not in the sarcopenic old. These findings suggest that a failure to expand the motor unit size distinguishes sarcopenic from pre‐sarcopenic muscles. The age‐related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques. We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men. These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men.
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Affiliation(s)
- M Piasecki
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - A Ireland
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - J Piasecki
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - D W Stashuk
- Department of Systems Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
| | - A Swiecicka
- Andrology Research Unit, Cardiovascular, Metabolic and Nutritional Sciences Domain, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - M K Rutter
- Andrology Research Unit, Cardiovascular, Metabolic and Nutritional Sciences Domain, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Manchester Diabetes Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - D A Jones
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - J S McPhee
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
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The reliability of methods to estimate the number and size of human motor units and their use with large limb muscles. Eur J Appl Physiol 2018; 118:767-775. [PMID: 29356950 PMCID: PMC5843678 DOI: 10.1007/s00421-018-3811-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/17/2018] [Indexed: 01/25/2023]
Abstract
Purpose Current methods for estimating muscle motor unit (MU) number provide values which are remarkably similar for muscles of widely differing size, probably because surface electrodes sample from similar and relatively small volumes in each muscle. We have evaluated an alternative means of estimating MU number that takes into account differences in muscle size. Methods Intramuscular motor unit potentials (MUPs) were recorded and muscle cross-sectional area (CSA) was measured using MRI to provide a motor unit number estimate (iMUNE). This was compared to the traditional MUNE method, using compound muscle action potentials (CMAP) and surface motor unit potentials (sMUPs) recorded using surface electrodes. Data were collected from proximal and distal regions of the vastus lateralis (VL) in young and old men while test–retest reliability was evaluated with VL, tibialis anterior and biceps brachii. Results MUPs, sMUPs and CMAPs were highly reliable (r = 0.84–0.91). The traditional MUNE, based on surface recordings, did not differ between proximal and distal sites of the VL despite the proximal CSA being twice the distal CSA. iMUNE, however, gave values that differed between young and old and were proportional to the muscle size. Conclusion When evaluating the contribution that MU loss makes to muscle atrophy, such as in disease or ageing, it is important to have a method such as iMUNE, which takes into account any differences in total muscle size.
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Picconi F, Mataluni G, Ziccardi L, Parravano M, Di Renzo A, Ylli D, Pasqualetti P, Studer V, Chioma L, Marfia GA, Frontoni S. Association between Early Neuroretinal Dysfunction and Peripheral Motor Unit Loss in Patients with Type 1 Diabetes Mellitus. J Diabetes Res 2018; 2018:9763507. [PMID: 30402503 PMCID: PMC6193343 DOI: 10.1155/2018/9763507] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/30/2018] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES It has been already confirmed that retinal neurodegeneration has a predictive value in the development of microvascular alterations in diabetic retinopathy. However, no data are available on the association between neuroretinal dysfunction and peripheral motor unit loss. Our study, therefore, was aimed at investigating the hypothesis that retinal neurodegeneration could be considered an early marker of diabetic peripheral neuropathy (DPN). METHODS 20 T1DM patients with no symptoms/signs of peripheral polyneuropathy, without DR or with very mild nonproliferative DR, and 14 healthy controls (C) age- and gender-matched were enrolled. The following electrophysiological tests were performed: standard nerve conduction studies (NCS) and incremental motor unit number estimation (MUNE) from the abductor hallux (AH) and abductor digiti minimi (ADM). Neuroretinal function was studied by multifocal electroretinogram (MfERG) recordings, measuring response amplitude density (RAD) and implicit time (IT) from rings and sectors of superior (S)/inferior (I)/temporal (T)/nasal (N) macular sectors up to 10 degrees of foveal eccentricity. RESULTS MfERG RADs from rings and sectors were significantly reduced in T1DM (p < 0.05) vs. C. ADM MUNE and AH MUNE were significantly decreased in T1DM (p = 0.039 and p < 0.0001, respectively) vs. C. A positive correlation between mean MfERG RADs from the central 5 degrees of the four (S, I, T, and N) macular sectors and lower limb motor unit number (r = 0.50, p = 0.041; r = 0.64, p = 0.005; r = 0.64, p = 0.006; and r = 0.61, p = 0.010, respectively) was observed in T1DM patients. No abnormalities of NCS were found in any subject. CONCLUSIONS The motor unit loss on the one hand and neuroretinal dysfunction on the other hand are already present in T1DM patients without DPN. The relationship between neuroretinal dysfunction and motor unit decline supports the hypothesis that neuroretina may represent a potential "window" to track the early neurogenic damage in diabetes.
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Affiliation(s)
- Fabiana Picconi
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita Fatebenefratelli Hospital, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giorgia Mataluni
- Unit of Disimmune Neuropathies, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | | | | | | | - Dorina Ylli
- Division of Endocrinology MedStar Washington Hospital Center, MedStar Health Research Institute, Washington, DC, USA
| | - Patrizio Pasqualetti
- Fatebenefratelli Foundation for Health Research and Education, AFaR Division, Rome, Italy
| | - Valeria Studer
- Unit of Disimmune Neuropathies, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
- Neuroimmunology and Neuromuscolar Diseases Unit, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Laura Chioma
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita Fatebenefratelli Hospital, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Girolama Alessandra Marfia
- Unit of Disimmune Neuropathies, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Simona Frontoni
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita Fatebenefratelli Hospital, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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Zhang C, Munoz A, Lai HH, Boone T, Zhang Y. Non-invasive electromyographic estimation of motor unit number in the external anal sphincter of the rat. Neurourol Urodyn 2017; 37:115-122. [PMID: 28884835 DOI: 10.1002/nau.23313] [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: 01/04/2017] [Accepted: 04/24/2017] [Indexed: 11/09/2022]
Abstract
AIMS The external anal sphincter (EAS) is essential for maintaining fecal continence. Neurological disorders or traumatic injuries to muscle and nervous systems could lead to EAS denervation. Currently, there are no techniques available to document global innervation changes in the EAS in vivo. The aim of this study was to develop a novel approach to non-invasively estimate the number of functioning motor units (MUs) in the EAS and validate with immunofluorescent techniques in rats. METHODS Intra-rectal surface electromyography (EMG) signals of the EAS, induced by a series of intra-vaginally delivered pudendal nerve stimulations with different intensities, were recorded. Variation in EMG responses at different intensities was used to estimate the value of a single motor unit potential (SMUP) in order to perform the proposed EAS motor unit number estimation (MUNE) approach. The EAS MUNE was tested in 12 female Sprague-Dawley rats, and validated by comparing against the EAS myofiber counting results achieved by performing immunostaining of acetylcholine receptors in 7 of the 12 rats. RESULTS The mean MU number was 35 ± 9, with an averaged SMUP size of 52.49 ± 20.39 μV. The mean number of successfully identified myofibers was 652.7 ± 130.6 myofiber/EAS. Significance of linear regression between the immunofluorescent results and the MUNE was confirmed (P < 0.01). CONCLUSIONS Our study represents the first effort to non-invasively assess the innervation of the EAS in vivo using the rat as a pre-clinical model. This approach can potentially enable future clinical applications for advanced diagnosis and treatment of neurogenic EAS disorders.
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Affiliation(s)
- Chuan Zhang
- Department of Biomedical Engineering, University of Houston, Houston, Texas.,Guangdong Provincial Work-injury Rehabilitation Hospital, Guangzhou, China.,Regenerative Medicine Program, Houston Methodist Research Institute, and Department of Urology, Houston Methodist Hospital, Houston, Texas
| | - Alvaro Munoz
- Regenerative Medicine Program, Houston Methodist Research Institute, and Department of Urology, Houston Methodist Hospital, Houston, Texas
| | - H Henry Lai
- Division of Urologic Surgery, Department of Surgery and Anesthesiology, Washington University School of Medicine, St Louis, Missouri
| | - Timothy Boone
- Regenerative Medicine Program, Houston Methodist Research Institute, and Department of Urology, Houston Methodist Hospital, Houston, Texas
| | - Yingchun Zhang
- Department of Biomedical Engineering, University of Houston, Houston, Texas.,Guangdong Provincial Work-injury Rehabilitation Hospital, Guangzhou, China.,Regenerative Medicine Program, Houston Methodist Research Institute, and Department of Urology, Houston Methodist Hospital, Houston, Texas
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Mandeville RM, Brown JM, Sheean GL. A neurophysiological approach to nerve transfer to restore upper limb function in cervical spinal cord injury. Neurosurg Focus 2017; 43:E6. [DOI: 10.3171/2017.5.focus17245] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A successful nerve transfer surgery can provide a wealth of benefits to a patient with cervical spinal cord injury. The process of surgical decision making ideally uses all pertinent information to produce the best functional outcome. Reliance on clinical examination and imaging studies alone can miss valuable information on the state of spinal cord health. In this regard, neurophysiological evaluation has the potential to effectively gauge the neurological status of even select pools of anterior horn cells and their axons to small nerve branches in question to determine the potential efficacy of their use in a transfer. If available preoperatively, knowledge gained from such an evaluation could significantly alter the reconstructive surgical plan and avoid poor results. The authors describe their institution’s approach to the assessment of patients with cervical spinal cord injury who are being considered for nerve transfer surgery in both the acute and chronic setting and broadly review the neurophysiological techniques used.
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Affiliation(s)
| | - Justin M. Brown
- 2Neurosurgery, University of California San Diego School of Medicine, La Jolla, California
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Motor unit number estimation in the quantitative assessment of severity and progression of motor unit loss in Hirayama disease. Clin Neurophysiol 2017; 128:1008-1014. [DOI: 10.1016/j.clinph.2017.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/21/2017] [Accepted: 03/05/2017] [Indexed: 12/12/2022]
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Zheng C, Zhu Y, Lu F, Ma X, Tian D, Jiang J. Trans-synaptic degeneration of motoneurons distal to chronic cervical spinal cord compression in cervical spondylotic myelopathy. Int J Neurosci 2017; 127:988-995. [PMID: 28125929 DOI: 10.1080/00207454.2017.1287701] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Chaojun Zheng
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
| | - Yu Zhu
- Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, NY, USA
| | - Feizhou Lu
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai, China
| | - Xiaosheng Ma
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
| | - Dong Tian
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
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Abstract
The motor unit comprises the anterior horn cell, its axon, and the muscle fibers that it innervates. Although the true number of motor units is unknown, the number of motor units appears to vary greatly between different muscles and between different individuals. Assessment of the number and function of motor units is needed in diseases of the anterior horn cell and other motor nerve disorders. Amyotrophic lateral sclerosis is the most important disease of anterior horn cells. The need for an effective biomarker for assessing disease progression and for use in clinical trials in amyotrophic lateral sclerosis has stimulated the study of methods to measure the number of motor units. Since 1970 a number of different methods, including the incremental, F-wave, multipoint, and statistical methods, have been developed but none has achieved widespread applicability. Two methods (MUNIX and the multipoint incremental method) are in current use across multiple centres and are discussed in detail in this review, together with other recently published methods. Imaging with magnetic resonance and ultrasound is increasingly being applied to this area. Motor unit number estimates have also been applied to other neuromuscular diseases such as spinal muscular atrophy, compression neuropathies, and prior poliomyelitis. The need for an objective measure for the assessment of motor units remains tantalizingly close but unfulfilled in 2016.
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Affiliation(s)
- Robert D Henderson
- Department of Neurology, Royal Brisbane & Women's Hospital and University of Queensland Centre for Clinical Research, Herston, Brisbane, 4006, Australia.
| | - Pamela A McCombe
- Department of Neurology, Royal Brisbane & Women's Hospital and University of Queensland Centre for Clinical Research, Herston, Brisbane, 4006, Australia
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de Carvalho M, Swash M. Lower motor neuron dysfunction in ALS. Clin Neurophysiol 2016; 127:2670-81. [DOI: 10.1016/j.clinph.2016.03.024] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/08/2016] [Accepted: 03/01/2016] [Indexed: 12/11/2022]
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Escorcio-Bezerra ML, Abrahao A, de Castro I, Chieia MAT, de Azevedo LA, Pinheiro DS, de Oliveira Braga NI, de Oliveira ASB, Manzano GM. MUNIX: Reproducibility and clinical correlations in Amyotrophic Lateral Sclerosis. Clin Neurophysiol 2016; 127:2979-2984. [PMID: 27458836 DOI: 10.1016/j.clinph.2016.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 05/05/2016] [Accepted: 06/12/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To study the reproducibility, diagnostic yield to detect denervation, and clinical correlations of the Motor Unit Number Index (MUNIX) in subjects with Amyotrophic Lateral Sclerosis (ALS). METHODS MUNIX evaluation was performed in three muscles twice on the same day to assess reproducibility. Cut-off values for the MUNIX were based on data from 51 healthy subjects (controls) to evaluate the sensitivity of the technique to detect denervation in 30 subjects with ALS. RESULTS The method had good reproducibility. The variability was greater in the ALS group. In 23 ALS subjects (77%), low MUNIX values were detected. Most of the muscles with low MUNIX had also low compound muscle action potential (CMAP) and strength, but these parameters were normal in 9% of muscles. According to ROC curve analysis, MUNIX was generally accurate (AUC=0.9504) for discriminating between healthy individuals and subjects with at least one denervated muscle. CONCLUSIONS MUNIX variability was higher in the ALS group. The method showed good diagnostic performance for the detection of denervation in a sample of patients with ALS. SIGNIFICANCE This study demonstrated that in addition to being a quantitative tool MUNIX can detect denervation in subjects with ALS.
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Affiliation(s)
| | | | - Isac de Castro
- Department of Medicine, Division of Molecular Medicine, University of São Paulo School of Medicine (FMUSP), Brazil
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Acetyl-L-carnitine (ALCAR) to enhance nerve regeneration in carpal tunnel syndrome: study protocol for a randomized, placebo-controlled trial. Trials 2016; 17:200. [PMID: 27079660 PMCID: PMC4832555 DOI: 10.1186/s13063-016-1324-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 04/01/2016] [Indexed: 11/17/2022] Open
Abstract
Background Carpal tunnel syndrome (CTS) is the most common form of peripheral nerve injury, affecting approximately 3 % of the population. While surgery is effective in mild and moderate cases, nerve and functional recovery are often not complete in severe cases. Therefore, there is a need for adjuvant methods to improve nerve regeneration in those cases. Acetyl-L-carnitine (ALCAR) is involved in lipid transport, vital for mitochondrial function. Although it has been shown to be effective in various forms of neuropathies, it has not been used in traumatic or compressive peripheral nerve injury. Methods In this pilot study we will utilize a double-blind, randomized, placebo-controlled design. Inclusion criteria will include adult patients with severe CTS. This will be confirmed by nerve conduction studies and motor unit number estimation (MUNE). Only those with severe motor unit loss in the thenar muscles (2 standard deviations [SD] below the mean for the age group) will be included. Eligible patients will be randomized to receive 3,000 mg/day of ALCAR orally or placebo following carpal tunnel release surgery for 2 months. The primary outcome will be MUNE with supplementary secondary outcome measures that include: 1) two-point discrimination; 2) Semmes-Weinstein monofilaments for pressure sensitivity; 3) cold and pain threshold for small fiber function; 4) Boston self-assessment Carpal Tunnel Questionnaire and 5) Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire for symptom severity; and 6) Purdue Pegboard Test for hand functional performance. To follow post treatment recovery and monitor safety, patients will be seen at 3 months, 6 months and 1 year. The outcome measures will be analyzed using two-way ANOVA, with treatment assignment and time points being the independent factors. If significant associations are detected, a post hoc analysis will be completed. We aim to recruit ten patients into each of the two groups. Data from this pilot will provide the basis for power calculation for a full-scale trial. Discussion ALCAR is a physiologic peptide crucial for fatty acid transport. ALCAR has been shown to be effective in neuroprotection in the central nervous system and increase peripheral nerve regeneration. This has been applied clinically to various systemic peripheral neuropathies including diabetic neuropathy, antiretroviral toxic neuropathy, and chemotherapy-induced peripheral neuropathy. While animal evidence exists for the benefit of ALCAR in compression neuropathy, there have been no human studies to date. This trial will represent the first use of ALCAR in peripheral nerve injury/compression neuropathy. Trial registration NCT02141035; 20 April 2015
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Yilmaz O, Sunter G, Salcini C, Koytak PK, Tanridag T, Us O, Uluc K. Motor-Unit Number Estimation Is Sensitive in Detecting Motor Nerve Involvement in Patients with Carpal Tunnel Syndrome. J Clin Neurol 2016; 12:166-71. [PMID: 26790466 PMCID: PMC4828562 DOI: 10.3988/jcn.2016.12.2.166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE We compared the motor-unit number estimation (MUNE) findings in patients who presented with signs and/or findings associated with carpal tunnel syndrome (CTS) and healthy controls, with the aim of determining if motor-unit loss occurs during the clinically silent period and if there is a correlation between clinical and MUNE findings in CTS patients. METHODS The study investigated 60 hands of 35 patients with clinical CTS and 60 hands of 34 healthy controls. Routine median and ulnar nerve conduction studies and MUNE analysis according to the multipoint stimulation method were performed. RESULTS The most common electrophysiological abnormality was reduced conduction velocity in the median sensory nerve (100% of the hands). The MUNE value was significantly lower for the patient group than for the control group (p=0.0001). ROC analysis showed that a MUNE value of 121 was the optimal cutoff for differentiating between patients and controls, with a sensitivity of 63.3% and a specificity of 68.3%. MUNE values were lower in patients with complaints of numbness, pain, and weakness in the median nerve territory (p<0.05, for all comparisons), and lower in patients with hypoesthesia than in patients with normal neurological findings (p=0.023). CONCLUSIONS The MUNE technique is sensitive in detecting motor nerve involvement in CTS patients who present with sensorial findings, and it may be useful in detecting the loss of motor units during the early stages of CTS. Larger-scale prospective clinical trials assessing the effect of early intervention on the outcome of these patients would help in confirming the possible benefit of detecting subclinical motor-unit loss in CTS.
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Affiliation(s)
- Orhan Yilmaz
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
| | - Gulin Sunter
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
| | - Celal Salcini
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
- Department of Neurology, Uskudar University, NPIstanbul Neuropsychiatry Hospital, Istanbul, Turkey
| | - Pınar Kahraman Koytak
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
| | - Tulin Tanridag
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
| | - Onder Us
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey
| | - Kayihan Uluc
- Department of Neurology, Marmara University Pendik Education and Research Hospital, Istanbul, Turkey.
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Fathi D, Mohammadi B, Dengler R, Böselt S, Petri S, Kollewe K. Lower motor neuron involvement in ALS assessed by motor unit number index (MUNIX): Long-term changes and reproducibility. Clin Neurophysiol 2016; 127:1984-8. [PMID: 26971480 DOI: 10.1016/j.clinph.2015.12.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 12/10/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Motor unit number estimation (MUNE) techniques such as motor unit number index (MUNIX) have been used to quantify lower motor neuron loss and disease progression in amyotrophic lateral sclerosis (ALS). We investigated the consistency of reproducibility of MUNIX in 30 ALS-patients during the course of the disorder. METHODS MUNIX was recorded in abductor pollicis brevis and tibialis anterior muscles bilaterally in ALS-patients by two measurements at the first and at one follow-up visit and once in healthy controls. Intra-rater reproducibility was evaluated by three statistical methods: interclass correlation coefficient (ICC), correlation coefficient analysis (CCA), and coefficient of variation (CV). RESULTS We found significant correlation between the first and second measurement of MUNIX in all tested muscles and at the follow-up visit (r⩾0.891, p<0.01) and good statistically significant reproducibility of MUNIX in all four measured muscles at the follow-up visit (ICC⩾0.946, p<0.01). The CV of MUNIX at the follow-up visit ranged from 13.90% to 32.95%. CONCLUSIONS This study shows good consistency of reproducibility of MUNIX in the course of ALS. SIGNIFICANCE This study suggests that MUNIX can be used to track the progression of the disorder both in clinical routine and in treatment trials.
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Affiliation(s)
- Davood Fathi
- Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran; International Neuroscience Institute, Hannover, Germany
| | - Bahram Mohammadi
- International Neuroscience Institute, Hannover, Germany; Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Reinhard Dengler
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Sebastian Böselt
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Susanne Petri
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Katja Kollewe
- Department of Neurology, Hannover Medical School, Hannover, Germany.
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Benatar M, Boylan K, Jeromin A, Rutkove SB, Berry J, Atassi N, Bruijn L. ALS biomarkers for therapy development: State of the field and future directions. Muscle Nerve 2015; 53:169-82. [PMID: 26574709 DOI: 10.1002/mus.24979] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2015] [Indexed: 12/11/2022]
Abstract
Biomarkers have become the focus of intense research in the field of amyotrophic lateral sclerosis (ALS), with the hope that they might aid therapy development efforts. Notwithstanding the discovery of many candidate biomarkers, none have yet emerged as validated tools for drug development. In this review we present a nuanced view of biomarkers based on the perspective of the Food and Drug Administration; highlight the distinction between discovery and validation; describe existing and emerging resources; review leading biological fluid-based, electrophysiological, and neuroimaging candidates relevant to therapy development efforts; discuss lessons learned from biomarker initiatives in related neurodegenerative diseases; and outline specific steps that we, as a field, might take to hasten the development and validation of biomarkers that will prove useful in enhancing efforts to develop effective treatments for ALS patients. Most important among these is the proposal to establish a federated ALS Biomarker Consortium in which all interested and willing stakeholders may participate with equal opportunity to contribute to the broader mission of biomarker development and validation.
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Affiliation(s)
- Michael Benatar
- Department of Neurology, University of Miami, Miami, Florida, USA, 33136
| | - Kevin Boylan
- Department of Neurology, Mayo Clinic Jacksonville, Jacksonville, Florida, USA
| | | | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - James Berry
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Nazem Atassi
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Kauder J, Petri S, Tipold A, Stein VM. The Potential Role of Motor Unit Number Estimation as an Additional Diagnostic and Prognostic Value in Canine Neurology. Front Vet Sci 2015; 2:53. [PMID: 26664980 PMCID: PMC4672275 DOI: 10.3389/fvets.2015.00053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/27/2015] [Indexed: 11/13/2022] Open
Abstract
Motor unit number estimation (MUNE) is an electrophysiological technique to assess the number of motor units innervating a single muscle or muscle group of interest. It may quantify axonal loss in any disease involving injury or degeneration of ventral horn cells or motor axons. Since MUNE has rarely been used in veterinary medicine, our study aimed to evaluate its potential role as an additional diagnostic and prognostic parameter in canine neurology. Therefore, we examined five healthy dogs and seven dogs suffering from diseases that necessitated general anesthesia for further diagnostics and treatment and that were not expected to interfere with the results of electrodiagnostic testing. By using the incremental technique to study MUNE in the cranial tibial muscle, we determined the number of motor units, the size of the compound muscle action potential, and the mean size of individual motor unit potentials of each dog as well as the mean values for each group. Moreover, we studied the correlation between these parameters. Taking the results into consideration, we addressed the difficulties and limitations of this technique. We, furthermore, pointed out possible fields of application for MUNE in canine neurology, and emphasized several aspects that future studies should focus on when applying MUNE to canine patients.
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Affiliation(s)
- Julia Kauder
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover , Hannover , Germany
| | - Susanne Petri
- Department of Neurology, Hannover Medical School , Hannover , Germany
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover , Hannover , Germany
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover , Hannover , Germany
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Piasecki M, Ireland A, Jones DA, McPhee JS. Age-dependent motor unit remodelling in human limb muscles. Biogerontology 2015; 17:485-96. [PMID: 26667009 PMCID: PMC4889636 DOI: 10.1007/s10522-015-9627-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/26/2015] [Indexed: 12/14/2022]
Abstract
Voluntary control of skeletal muscle enables humans to interact with and manipulate the environment. Lower muscle mass, weakness and poor coordination are common complaints in older age and reduce physical capabilities. Attention has focused on ways of maintaining muscle size and strength by exercise, diet or hormone replacement. Without appropriate neural innervation, however, muscle cannot function. Emerging evidence points to a neural basis of muscle loss. Motor unit number estimates indicate that by age around 71 years, healthy older people have around 40 % fewer motor units. The surviving low- and moderate-threshold motor units recruited for moderate intensity contractions are enlarged by around 50 % and show increased fibre density, presumably due to collateral reinnervation of denervated fibres. Motor unit potentials show increased complexity and the stability of neuromuscular junction transmissions is decreased. The available evidence is limited by a lack of longitudinal studies, relatively small sample sizes, a tendency to examine the small peripheral muscles and relatively few investigations into the consequences of motor unit remodelling for muscle size and control of movements in older age. Loss of motor neurons and remodelling of surviving motor units constitutes the major change in ageing muscles and probably contributes to muscle loss and functional impairments. The deterioration and remodelling of motor units likely imposes constraints on the way in which the central nervous system controls movements.
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Affiliation(s)
- Mathew Piasecki
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - Alex Ireland
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - David A Jones
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK
| | - Jamie S McPhee
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15GD, UK.
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Li X, Nandedkar SD, Zhou P. Modified motor unit number index: A simulation study of the first dorsal interosseous muscle. Med Eng Phys 2015; 38:115-20. [PMID: 26639774 DOI: 10.1016/j.medengphy.2015.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 10/23/2015] [Accepted: 11/06/2015] [Indexed: 12/14/2022]
Abstract
The motor unit number index (MUNIX) technique has provided a quick and convenient approach to estimating motor unit population changes in a muscle. Reduction in motor unit action potential (MUAP) amplitude can lead to underestimation of motor unit numbers using the standard MUNIX technique. This study aims to overcome this limitation by developing a modified MUNIX (mMUNIX) technique. The mMUNIX uses a variable that is associated with the area of compound muscle action potential (CMAP) rather than an arbitrary fixed value (20 mV ms) as used in the standard MUNIX to define the output. The performance of the mMUNIX was evaluated using motoneuron pool and surface electromyography (EMG) models. With a fixed motor unit number, the mMUNIX output remained relatively constant with varying degrees of MUAP amplitude changes, while the standard MUNIX substantially underestimated the motor unit number in such cases. However, when MUAP amplitude remained unchanged, the mMUNIX showed less sensitivity than the standard MUNIX in tracking motor unit loss. The current simulation study demonstrated both the advantages and limitations of the standard and modified MUNIX techniques, which can help guide appropriate application and interpretation of MUNIX measurements.
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Affiliation(s)
- Xiaoyan Li
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, 1333B Moursund St., Houston, TX, USA; TIRR Memorial Hermann Research Center, Houston, TX, USA.
| | | | - Ping Zhou
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, 1333B Moursund St., Houston, TX, USA; TIRR Memorial Hermann Research Center, Houston, TX, USA; Guangdong Work Injury Rehabilitation Center, Guangzhou, China
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Li X, He W, Li C, Wang YC, Slavens BA, Zhou P. Motor unit number index examination in dominant and non-dominant hand muscles. Laterality 2015; 20:699-710. [PMID: 26227495 DOI: 10.1080/1357650x.2015.1041971] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study investigated the effect of handedness on motor unit number index (MUNIX). Maximal hand strength, compound muscle action potential (CMAP) and voluntary surface electromyography (EMG) signals were measured bilaterally for the first dorsal interosseous (FDI) and thenar muscles in 24 right-handed and 2 left-handed healthy subjects. Mean (±standard error) grip and pinch forces in the dominant hand were 43.99 ± 2.36 kg and 9.36 ± 0.52 kg respectively, significantly larger than those in the non-dominant hand (grip: 41.37 ± 2.29 kg, p < .001; pinch: 8.79 ± 0.46 kg, p < .01). Examination of myoelectric parameters did not show a significant difference among the CMAP area, the MUNIX or motor unit size index (MUSIX) between the two sides in the FDI and thenar muscles. In addition, there was a lack of correlation between the strength and myoelectric parameters in regression analysis. However, strong correlations were observed between dominant and non-dominant hand muscles in both strength and myoelectric measures. Our results indicate that the population of motor units or spinal motor neurons as estimated from MUNIX may not be associated with handedness. Such findings help understand and interpret the MUNIX during its application for clinical or laboratory investigations.
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Affiliation(s)
- Xiaoyan Li
- a Department of Physical Medicine and Rehabilitation , University of Texas Health Science Center at Houston, and TIRR Memorial Hermann Research Center , Houston , TX , USA
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McKinnon NB, Montero-Odasso M, Doherty TJ. Motor unit loss is accompanied by decreased peak muscle power in the lower limb of older adults. Exp Gerontol 2015; 70:111-8. [PMID: 26190479 DOI: 10.1016/j.exger.2015.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 12/14/2022]
Abstract
This study investigated the relationship between motor unit (MU) properties and the isometric strength and power of two lower limb muscles in healthy young and older adults. Twelve older adults (6 men, mean age, 77 ± 5 years) and twelve young adults (6 men, mean age, 24 ± 3 years) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined electrophysiologically using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNEs) of the TA were significantly reduced (p<0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected motor unit potentials (S-MUPs) in older adults (63 ± 29 μV) compared to young adults (27 ± 14 μV). Although VM S-MUP values were larger in older adults (60 ± 31 μV) compared to young (48 ± 42 μV), the difference was not significant. Maximal isometric strength was significantly larger in both the TA and knee extensors of young adults (TA: 0.56 Nm/kg, KE: 2.2 Nm/kg) compared to old (TA: 0.4 Nm/kg, KE: 1.3 Nm/kg). Similar reductions in peak muscle power were observed between young (TA: 33 W, KE: 35 7 W) and old adults (TA: 26 W, KE: 224 W). The greatest deficit between young and old subjects in peak power output occurred at 20% MVC for the TA and 40% MVC for the knee extensors. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the more distal TA muscle. Further, this study demonstrates that muscle power may be a sensitive marker of changes in neuromuscular function with aging.
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Affiliation(s)
- Neal B McKinnon
- School of Health and Rehabilitation Sciences, Faculty of Health Sciences, Western University, London, Ontario, Canada
| | - Manuel Montero-Odasso
- Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute, Canada; Division of Geriatric Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Timothy J Doherty
- School of Health and Rehabilitation Sciences, Faculty of Health Sciences, Western University, London, Ontario, Canada; Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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Abstract
Progressive weakness remains the clinical hallmark of amyotrophic lateral sclerosis (ALS). Accordingly, a variety of tools has been developed to capture this disease feature, including questionnaires, such as the ALS-functional rating scale, strength testing, pulmonary function tests, electrophysiologic measures, including motor unit number estimation, and imaging techniques. Despite this plethora of approaches, there is little agreement as to what measures to use in a given clinical trial or in the clinic during routine patient care. Part of the reason for this uncertainty is that ALS is a remarkably protean disease. Some individuals progress rapidly, others slowly; some patients have considerable upper motor neuron dysfunction, whereas others have little; and there is considerable variation in the sequence of body regions affected, in some the disease beginning in the bulbar musculature and in others in one arm or one leg. Here, I present a variety of basic and more complex clinical measures for potential use in therapeutic trials with the aim of offering a balanced and practical set of recommendations, as well as considerations for future studies.
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Affiliation(s)
- Seward B Rutkove
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA,
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Motor unit number index (MUNIX) in the orbicularis oculi muscle of healthy subjects. Muscle Nerve 2014; 51:197-200. [DOI: 10.1002/mus.24292] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/13/2014] [Accepted: 05/16/2014] [Indexed: 11/07/2022]
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Kouzi I, Trachani E, Anagnostou E, Rapidi CA, Ellul J, Sakellaropoulos GC, Chroni E. Motor unit number estimation and quantitative needle electromyography in stroke patients. J Electromyogr Kinesiol 2014; 24:910-6. [PMID: 25304197 DOI: 10.1016/j.jelekin.2014.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 09/06/2014] [Accepted: 09/08/2014] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To evaluate the effect of upper motor neuron damage upon motor units' function by means of two separate and supplementary electrophysiological methods. METHODS The abductor digiti minimi muscle of the non-paretic and the paretic side was studied in forty-six stroke patients with (a) motor unit number estimation (MUNE) - adapted multiple point stimulation method and (b) computerized quantitative needle electromyography (EMG) assessing the configuration of voluntary recruited motor unit potentials. Main outcome comparisons were focused on differences between non-paretic and paretic side. RESULTS On the affected hands mean MUNE value was significantly lower and mean area of the surface recorded single motor unit potentials was significantly larger than the corresponding ones on the non-paretic hands. EMG findings did not reveal remarkable differences between the two sides. Neither severity nor chronicity of stroke was related to MUNE or EMG parameters. DISCUSSION MUNE results, which suggested reduced motor unit numbers in stroke patients, in conjunction with the normal EMG features in these same muscles has given rise to different interpretations. In a clinical setting, reinnervation type changes in the EMG similar to that occurring in neuronopathies or axonal neuropathies should not be expected in muscles with central neurogenic lesion.
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Affiliation(s)
- Ioanna Kouzi
- Departments of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Eftichia Trachani
- Departments of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Evangelos Anagnostou
- Departments of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Christina-Anastasia Rapidi
- Departments of Spinal Cord Lesions Rehabilitation, School of Medicine, University of Patras, Patras, Greece
| | - John Ellul
- Departments of Neurology, School of Medicine, University of Patras, Patras, Greece
| | | | - Elisabeth Chroni
- Departments of Neurology, School of Medicine, University of Patras, Patras, Greece.
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Zhou P, Nandedkar SD, Barkhaus PE. Voluntary Contraction Direction Dependence of Motor Unit Number Index in Patients with Amyotrophic Lateral Sclerosis. IEEE Trans Neural Syst Rehabil Eng 2014; 22:992-6. [DOI: 10.1109/tnsre.2014.2314391] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Li X, Liu J, Li S, Wang YC, Zhou P. Examination of hand muscle activation and motor unit indices derived from surface EMG in chronic stroke. IEEE Trans Biomed Eng 2014; 61:2891-8. [PMID: 24967982 DOI: 10.1109/tbme.2014.2333034] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this study, we used muscle and motor unit indices, derived from convenient surface electromyography (EMG) measurements, for examination of paretic muscle changes post stroke. For 12 stroke subjects, compound muscle action potential and voluntary surface EMG signals were recorded from paretic and contralateral first dorsal interosseous, abductor pollicis brevis, and abductor digiti minimi muscles. Muscle activation index (AI), motor unit number index (MUNIX), and motor unit size index (MUSIX) were then calculated for each muscle. There was a significant AI reduction for all the three muscles in paretic side compared with contralateral side, providing an evidence of muscle activation deficiency after stroke. The hand MUNIX (defined by summing the values from the three muscles) was significantly reduced in paretic side compared with contralateral side, whereas the hand MUSIX was not significantly different. Furthermore, diverse changes in MUNIX and MUSIX were observed from the three muscles. A major feature of the present examinations is the primary reliance on surface EMG, which offers practical benefits because it is noninvasive, induces minimal discomfort and can be performed quickly.
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Unlusoy Acar Z, Yalinay Dikmen P, Yayla V, Başaran K, Emekli U, Öge AE. Decline of compound muscle action potentials and statistical MUNEs during Wallerian degeneration. Neurophysiol Clin 2014; 44:257-65. [PMID: 25240559 DOI: 10.1016/j.neucli.2014.04.003] [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] [Received: 10/08/2012] [Revised: 01/21/2014] [Accepted: 04/12/2014] [Indexed: 12/12/2022] Open
Abstract
AIM OF THE STUDY In two previous studies, we found that the compound muscle action potential (CMAP) amplitude loss was significantly higher than the loss of estimated motor unit numbers in the course of Wallerian degeneration (WD). In order to overcome some drawbacks of the method previously used, we performed a similar CMAP vs MUNE comparison by using the statistical motor unit number estimation (MUNE) method. PATIENTS AND METHODS Initial electrophysiological studies on 6 patients were performed between 22 and 98 hours after the injuries; it was possible to make repeated examinations, four times in 1 nerve, twice in 1 nerve and three times in 4 nerves, before the eventual complete disappearance of the CMAPs. RESULTS The transected/intact (T/I) side CMAP ratios declined steeply as WD evolved. They were significantly lower than the relatively stable MUNE ratios 48 hours after the injury. CONCLUSION This study, performed with the use of statistical MUNE, strengthens our previous observation by the incremental method that might have some relevance to the pathophysiology of early WD. CMAP amplitude loss that is more than expected from the amount of axonal degeneration may indicate a considerable amount of inactive muscle fibers in the motor units innervated by the nerve fibers, which are undergoing degeneration but still retain their excitability. Although technical sources of error cannot be totally excluded, our findings could more likely be explained by the failing of neuromuscular synapses in an asynchronous order before complete unresponsiveness of the motor unit ensues.
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Affiliation(s)
- Z Unlusoy Acar
- Department of Neurology, TDV 29 May Hospital, 34091 Istanbul, Turkey
| | - P Yalinay Dikmen
- Department of Neurology, Acıbadem University School of Medicine, 34140 Istanbul, Turkey.
| | - V Yayla
- Department of Neurology, Dr. Sadi Konuk Bakırköy Education and Research Hospital, 34147 Istanbul, Turkey
| | - K Başaran
- Department of Plastic and Reconstructive Surgery, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
| | - U Emekli
- Department of Plastic and Reconstructive Surgery, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
| | - A E Öge
- Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
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Stevens DES, Harwood B, Power GA, Doherty TJ, Rice CL. Anconeus motor unit number estimates using decomposition-based quantitative electromyography. Muscle Nerve 2014; 50:52-9. [PMID: 24123180 DOI: 10.1002/mus.24092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/02/2013] [Accepted: 10/04/2013] [Indexed: 11/06/2022]
Abstract
INTRODUCTION Motor unit number estimates (MUNEs) provide important information in health, aging, and disease, and can be determined using decomposition-enhanced spike-triggered averaging (DE-STA). Discrimination of surface-detected motor unit potentials (S-MUPs) has been limited to contractile forces of ∽30% maximum voluntary contraction (MVC), which is insufficient to recruit a representative sample of the entire MU pool in most muscles. Unique features of the anconeus may permit MUNEs at high muscle activation levels. METHODS In 10 men (25 ± 3 years), anconeus MUNEs were performed using DE-STA at 10%, 30%, and 50% root-mean-square of MVC (RMS(MVC)). RESULTS The mean compound muscle action potential of the anconeus was ∽6 mV, and average S-MUP amplitudes were ∽100 μV, 145 μV, and 235 μV at 10%, 30%, and 50% RMS(MVC), resulting in low average MUNEs of 58, 38, and 25, respectively. CONCLUSIONS Elbow extensor force-EMG relationships suggest full recruitment of the anconeus MU pool at 50% RMS(MVC), thus providing a representative sample for MUNE.
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Affiliation(s)
- Daniel E S Stevens
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, Ontario, Canada
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Drovandi CC, Pettitt AN, Henderson RD, McCombe PA. Marginal reversible jump Markov chain Monte Carlo with application to motor unit number estimation. Comput Stat Data Anal 2014. [DOI: 10.1016/j.csda.2013.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Arezzo JC, Seto S, Schaumburg HH. Sensory-motor assessment in clinical research trials. HANDBOOK OF CLINICAL NEUROLOGY 2014; 115:265-78. [PMID: 23931786 DOI: 10.1016/b978-0-444-52902-2.00016-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
The assessment of changes in sensory-motor function in clinical research presents a unique set of difficulties. Clinimetrics is the science of measurement as related to the identification of a clinical disorder, the tracing of the progression of the condition under study, and calculation of its impact. The selection of appropriate measures for clinical studies of sensory-motor function must consider validity, sensitivity, specificity, responsiveness, reliability, and feasibility. Reasonable measures of motor function in clinical research include manual examination of muscle strength, electrophysiology, functional scales, patient-reported outcomes (e.g., quality of life), and for severe conditions such as ALS, survival. The assessment of sensory function includes targeted electrophysiology and QOL, as well as more focused measures such as quantitative sensory testing and the scoring of positive symptoms. Each individual measure and each combination of endpoints has its strengths and limitations.
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Affiliation(s)
- Joseph C Arezzo
- Department of Neuroscience, Albert Einstein College of Medicine, New York, USA; Department of Neurology, Albert Einstein College of Medicine, New York, USA.
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Power GA, Dalton BH, Rice CL. Human neuromuscular structure and function in old age: A brief review. JOURNAL OF SPORT AND HEALTH SCIENCE 2013; 2:215-226. [PMID: 27011872 PMCID: PMC4801513 DOI: 10.1016/j.jshs.2013.07.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Natural adult aging is associated with many functional impairments of the human neuromuscular system. One of the more observable alterations is the loss of contractile muscle mass, termed sarcopenia. The loss of muscle mass occurs primarily due to a progressive loss of viable motor units, and accompanying atrophy of remaining muscle fibers. Not only does the loss of muscle mass contribute to impaired function in old age, but alterations in fiber type and myosin heavy chain isoform expression also contribute to weaker, slower, and less powerful contracting muscles. This review will focus on motor unit loss associated with natural adult aging, age-related fatigability, and the age-related differences in strength across contractile muscle actions.
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Affiliation(s)
- Geoffrey A. Power
- Human Performance Laboratory, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Brian H. Dalton
- School of Kinesiology, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Charles L. Rice
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario N6A 5B1, Canada
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario N6A 5C1, Canada
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Kurimoto S, Kato S, Nakano T, Yamamoto M, Takanobu N, Hirata H. Transplantation of embryonic motor neurons into peripheral nerve combined with functional electrical stimulation restores functional muscle activity in the rat sciatic nerve transection model. J Tissue Eng Regen Med 2013; 10:E477-E484. [DOI: 10.1002/term.1844] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 09/14/2013] [Accepted: 09/17/2013] [Indexed: 01/25/2023]
Affiliation(s)
- Shigeru Kurimoto
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
| | - Shuichi Kato
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
| | - Tomonori Nakano
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
| | - Michiro Yamamoto
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
| | - Nishizuka Takanobu
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
| | - Hitoshi Hirata
- Department of Hand Surgery; Nagoya University Graduate School of Medicine; Japan
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