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Barkhaus PE, Nandedkar SD, de Carvalho M, Swash M, Stålberg EV. Revisiting the compound muscle action potential (CMAP). Clin Neurophysiol Pract 2024; 9:176-200. [PMID: 38807704 PMCID: PMC11131082 DOI: 10.1016/j.cnp.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/15/2024] [Accepted: 04/21/2024] [Indexed: 05/30/2024] Open
Abstract
The compound muscle action potential (CMAP) is among the first recorded waveforms in clinical neurography and one of the most common in clinical use. It is derived from the summated muscle fiber action potentials recorded from a surface electrode overlying the studied muscle following stimulation of the relevant motor nerve fibres innervating the muscle. Surface recorded motor unit potentials (SMUPs) are the fundamental units comprising the CMAP. Because it is considered a basic, if not banal signal, what it represents is often underappreciated. In this review we discuss current concepts in the anatomy and physiology of the CMAP. These have evolved with advances in instrumentation and digitization of signals, affecting its quantitation and measurement. It is important to understand the basic technical and biological factors influencing the CMAP. If these influences are not recognized, then a suboptimal recording may result. The object is to obtain a high quality CMAP recording that is reproducible, whether the study is done for clinical or research purposes. The initial sections cover the relevant CMAP anatomy and physiology, followed by how these principles are applied to CMAP changes in neuromuscular disorders. The concluding section is a brief overview of CMAP research where advances in recording systems and computer-based analysis programs have opened new research applications. One such example is motor unit number estimation (MUNE) that is now being used as a surrogate marker in monitoring chronic neurogenic processes such as motor neuron diseases.
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Affiliation(s)
- Paul E. Barkhaus
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI USA
| | - Sanjeev D. Nandedkar
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI USA
- Natus Medical Inc., Hopewell Junction, NY, USA
| | - Mamede de Carvalho
- Instituto de Medicina Molecular and Institute of Physiology, Centro de Estudos Egas Moniz, Faculty of Medicine, University of Lisbon, Portugal
- Department of Neurosciences and Mental Health, CHULN-Hospital de Santa Maria, Lisbon, Portugal
| | - Michael Swash
- Barts and the London School of Medicine, Queen Mary University of London, London UK
| | - Erik V. Stålberg
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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Klein CS, Liu H, Xiong Y. Estimation of the number of motor units in the human extensor digitorum brevis using MScanFit. PLoS One 2024; 19:e0302214. [PMID: 38669263 PMCID: PMC11051589 DOI: 10.1371/journal.pone.0302214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/30/2024] [Indexed: 04/28/2024] Open
Abstract
OBJECTIVE Our aim was to determine the number and size parameters of EDB motor units in healthy young adults using MScanFit, a novel approach to motor unit number estimation (MUNE). Since variability in MUNE is related to compound muscle action potential (CMAP) size, we employed a procedure to document the optimal EDB electromyographic (EMG) electrode position prior to recording MUNE, a neglected practice in MUNE. METHODS Subjects were 21 adults 21-44 y. Maximum CMAPs were recorded from 9 sites in a 4 cm2 region centered over the EDB and the site with the largest amplitude was used in the MUNE experiment. For MUNE, the peroneal nerve was stimulated at the fibular head to produce a detailed EDB stimulus-response curve or "MScan". Motor unit number and size parameters underlying the MScan were simulated using the MScanFit mathematical model. RESULTS In 19 persons, the optimal recording site was superior, superior and proximal, or superior and distal to the EDB mid-belly, whereas in 3 persons it was proximal to the mid-belly. Ranges of key MScanFit parameters were as follows: maximum CMAP amplitude (3.1-8.5 mV), mean SMUP amplitude (34.4-106.7 μV), mean normalized SMUP amplitude (%CMAP max, 0.95-2.3%), largest SMUP amplitude (82.7-348 μV), and MUNE (43-103). MUNE was not related to maximum CMAP amplitude (R2 = 0.09), but was related to mean SMUP amplitude (R2 = -0.19, P = 0.05). CONCLUSION The EDB CMAP was highly sensitive to electrode position, and the optimal position differed between subjects. Individual differences in EDB MUNE were not related to CMAP amplitude. Inter-subject variability of EDB MUNE (coefficient of variation) was much less than previously reported, possibly explained by better optimization of the EMG electrode and the unique approach of MScanFit MUNE.
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Affiliation(s)
- Cliff S. Klein
- Guangdong Work Injury Rehabilitation Center, Guangzhou, Guangdong, China
| | - Hui Liu
- Guangdong Work Injury Rehabilitation Center, Guangzhou, Guangdong, China
| | - Yuan Xiong
- Guangdong Work Injury Rehabilitation Center, Guangzhou, Guangdong, China
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Rodriguez‐Falces J, Etxaleku S, Trajano GS, Setuain I. The contribution of the tendon electrode to M-wave characteristics in the biceps brachii, vastus lateralis and tibialis anterior. Exp Physiol 2023; 108:1548-1559. [PMID: 37988249 PMCID: PMC10988423 DOI: 10.1113/ep091472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/30/2023] [Indexed: 11/23/2023]
Abstract
In some compound muscle action potentials (M waves) recorded using the belly-tendon configuration, the tendon electrode makes a noticeable contribution to the M wave. However, this finding has only been demonstrated in some hand and foot muscles. Here, we assessed the contribution of the tendon potential to the amplitude of the vastus lateralis, biceps brachii and tibialis anterior M waves, and we also examined the role of this tendon potential in the shoulder-like feature appearing in most M waves. M waves were recorded separately at the belly and tendon locations of the vastus lateralis, biceps brachii and tibialis anterior from 38 participants by placing the reference electrode at a distant (contralateral) site. The amplitude of the M waves and the latency of their peaks and shoulders were measured. In the vastus lateralis, the tendon potential was markedly smaller in amplitude (∼75%) compared to the belly M wave (P = 0.001), whereas for the biceps brachii and tibialis anterior, the tendon and belly potentials had comparable amplitudes. In the vastus lateralis, the tendon potential showed a small positive peak coinciding in latency with the shoulder of the belly-tendon M wave, whilst in the biceps brachii and tibialis anterior, the tendon potential showed a clear negative peak which coincided in latency with the shoulder. The tendon potential makes a significant contribution to the belly-tendon M waves of the biceps brachii and tibialis anterior muscles, but little contribution to the vastus lateralis M waves. The shoulder observed in the belly-tendon M wave of the vastus lateralis is caused by the belly potential, the shoulder in the biceps brachii M wave is generated by the tendon potential, whereas the shoulder in the tibialis anterior M wave is caused by both the tendon and belly potentials. NEW FINDINGS: What is the central question of this study? Does a tendon electrode make a noticeable contribution to the belly-tendon M wave in the vastus lateralis, biceps brachii and tibialis anterior muscles? What is the main finding and its importance? Because the patellar tendon potential is small in amplitude, it hardly influences the amplitude and shape of the belly-tendon M wave of the vastus lateralis. However, for the biceps brachii and tibialis anterior muscles, the potentials at the tendon sites show a large amplitude, and thus have a great impact on the corresponding belly-tendon M waves.
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Affiliation(s)
- Javier Rodriguez‐Falces
- Department of Electrical and Electronical EngineeringPublic University of NavarraPamplonaSpain
| | - Saioa Etxaleku
- Clinical Research DepartmentTDN, Orthopedic Surgery and Advanced Rehabilitation CenterMutilvaSpain
| | - Gabriel S. Trajano
- Faculty of Health, School of Exercise and Nutrition SciencesQueensland University of Technology (QUT)BrisbaneQueenslandAustralia
| | - Igor Setuain
- Clinical Research DepartmentTDN, Orthopedic Surgery and Advanced Rehabilitation CenterMutilvaSpain
- Department of Health SciencesPublic University of NavarrePamplonaSpain
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Fan DS, Zhang YX, Ma JY, Liu XY, Zhang S, Yu Z. Promising application of a new ulnar nerve compound muscle action potential measurement montage in amyotrophic lateral sclerosis: a prospective cross-sectional study. Neural Regen Res 2023; 18:908-912. [DOI: 10.4103/1673-5374.353499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Rodriguez-Falces J, Etxaleku S, Setuain I, Malanda A, Navallas J. The influence of the reference electrode location on the M-wave characteristics in the quadriceps. J Electromyogr Kinesiol 2022; 66:102681. [PMID: 35868091 DOI: 10.1016/j.jelekin.2022.102681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION In the compound muscle action potential (M wave) recorded using the belly-tendon configuration, the contribution of the tendon electrode is assumed to be negligible compared to the belly electrode. We tested this assumption by placing the reference electrode at a distant (contralateral) site, which allowed separate recording of the belly and tendon contributions. METHODS M waves were recorded at multiple selected sites over the right quadriceps heads and lower leg using two different locations for the reference electrode: the ipsilateral (right) and contralateral (left) patellar tendon. The general parameters of the M wave (amplitude, area, duration, latency, and frequency) were measured. RESULTS (1) The tendon potential had a small amplitude (<30%) compared to the belly potential; (2) Changing the reference electrode from the ipsilateral to the contralateral patella produced moderate changes in the M wave recorded over the innervation zone, these changes affecting significantly the amplitude of the M-wave second phase (p = 0.006); (3) Using the contralateral reference system allowed recording of short-latency components occurring immediately after the stimulus artefact, which had the same latency and amplitude (p = 0.18 and 0.25, respectively) at all recording sites over the leg. CONCLUSIONS The potential recorded at the "tendon" site after femoral nerve stimulation is small (compared to the belly potential), but not negligible, and makes a significant contribution to the second phase of belly-tendon M wave. Adopting a distant (contralateral) reference allowed recording of far-field components that may aid in the understanding of the electrical formation of the M wave.
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Affiliation(s)
- Javier Rodriguez-Falces
- Department of Electrical and Electronical Engineering, Public University of Navarra, Pamplona, Spain.
| | - Saioa Etxaleku
- TDN, Orthopedic Surgery and Advanced Rehabilitation Center, Clinical Research Department, Mutilva, Spain
| | - Igor Setuain
- TDN, Orthopedic Surgery and Advanced Rehabilitation Center, Clinical Research Department, Mutilva, Spain
| | - Armando Malanda
- Department of Electrical and Electronical Engineering, Public University of Navarra, Pamplona, Spain
| | - Javier Navallas
- Department of Electrical and Electronical Engineering, Public University of Navarra, Pamplona, Spain
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Reijntjes RH, Potters WV, Kerkhof FI, van Zwet E, van Rossum IA, Verhamme C, Tannemaat MR. Deriving reference values for nerve conduction studies from existing data using mixture model clustering. Clin Neurophysiol 2021; 132:1820-1829. [PMID: 34130250 DOI: 10.1016/j.clinph.2021.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 03/23/2021] [Accepted: 04/10/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVE to obtain locally valid reference values (RVs) from existing nerve conduction study (NCS) data. METHODS we used age, sex, height and limb temperature-based mixture model clustering (MMC) to identify normal and abnormal measurements on NCS data from two university hospitals. We compared MMC-derived RVs to published data; examined the effect of using different variables; validated MMC-derived RVs using independent data from 26 healthy control subjects and investigated their clinical applicability for the diagnosis of polyneuropathy. RESULTS MMC-derived RVs were similar to published RVs. Clustering can be achieved using only sex and age as variables. MMC is likely to yield reliable results with fewer abnormal than normal measurements and when the total number of measurements is at least 300. Measurements from healthy controls fell within the 95% MMC-derived prediction interval in 97.4% of cases. CONCLUSIONS MMC can be used to obtain RVs from existing data, providing a locally valid, accurate reflection of the (ab)normality of an NCS result. SIGNIFICANCE MMC can be used to generate locally valid RVs for any test for which sufficient data are available.1.
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Affiliation(s)
- R H Reijntjes
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.
| | - W V Potters
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands.
| | - F I Kerkhof
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.
| | - E van Zwet
- Department of Biostatistics, Leiden University Medical Center, Leiden, the Netherlands.
| | - I A van Rossum
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.
| | - C Verhamme
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands.
| | - M R Tannemaat
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.
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Willems J, Mathieu T, Gorissen D. Anterior shin muscles CMAP measurements: Normal limits of symmetry and intra- and interobserver reliability. Clin Neurophysiol Pract 2021; 6:93-96. [PMID: 33748551 PMCID: PMC7966827 DOI: 10.1016/j.cnp.2021.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 01/11/2021] [Accepted: 02/08/2021] [Indexed: 12/02/2022] Open
Abstract
The CMAPshin measurement is a convenient and safe method with good intra-observer reliability. The right-left difference in the CMAPshin amplitude/area is likely pathological where a difference is more then 25%. This method can be used to estimate the axonal loss in lesions involving these muscles.
Objective The normal limits of symmetry for the compound muscle action potential of the shin muscles (CMAPshin) have not been determined yet. The goal of this study is to provide extensive data on the limits of symmetry and the reliability of CMAPshin. Methods The study was conducted in normal healthy males and females. All subjects underwent CMAPshin measurements bilaterally. The median percent differences of right/left amplitude/area, with range of these measurements, were calculated. In addition, the intra- and interobserver reliability was examined in a separate population. Results The study group consisted of 58 healthy individuals. The median percent right/left difference for amplitude and area were respectively 7.2% (range 0–23.6%) and 5.4% (range 0.7–25.6%). Right/left difference of the amplitude/area of the CMAPshin greater than 24%/26% respectively can be considered as pathological. The Pearson correlation coefficients (r) for the intra-observer reliability amplitude/area are 0.905/0.882 and for the inter-observer reliability are 0.968/0.981. Conclusions The results confirm symmetry and good intra- and interobserver reliability in CMAPshin measurements. Significance CMAPshin can be used in practice to estimate axonal loss in case of a foot drop. Data studies examining symmetry of CMAPshin can facilitate in the clinical interpretation of these nerve conduction studies.
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Affiliation(s)
- Jan Willems
- Department of Physical Medicine and Rehabilitation, ZNA Middelheim, Antwerp, Belgium
| | - Thomas Mathieu
- Department of Physical Medicine and Rehabilitation, ZNA Middelheim, Antwerp, Belgium.,Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Dagmar Gorissen
- Department of Physical Medicine and Rehabilitation, ZNA Middelheim, Antwerp, Belgium
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Prukop T, Wernick S, Boussicault L, Ewers D, Jäger K, Adam J, Winter L, Quintes S, Linhoff L, Barrantes-Freer A, Bartl M, Czesnik D, Zschüntzsch J, Schmidt J, Primas G, Laffaire J, Rinaudo P, Brureau A, Nabirotchkin S, Schwab MH, Nave KA, Hajj R, Cohen D, Sereda MW. Synergistic PXT3003 therapy uncouples neuromuscular function from dysmyelination in male Charcot-Marie-Tooth disease type 1A (CMT1A) rats. J Neurosci Res 2020; 98:1933-1952. [PMID: 32588471 DOI: 10.1002/jnr.24679] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/13/2020] [Accepted: 05/31/2020] [Indexed: 12/11/2022]
Abstract
Charcot-Marie-Tooth disease 1 A (CMT1A) is caused by an intrachromosomal duplication of the gene encoding for PMP22 leading to peripheral nerve dysmyelination, axonal loss, and progressive muscle weakness. No therapy is available. PXT3003 is a low-dose combination of baclofen, naltrexone, and sorbitol which has been shown to improve disease symptoms in Pmp22 transgenic rats, a bona fide model of CMT1A disease. However, the superiority of PXT3003 over its single components or dual combinations have not been tested. Here, we show that in a dorsal root ganglion (DRG) co-culture system derived from transgenic rats, PXT3003 induced myelination when compared to its single and dual components. Applying a clinically relevant ("translational") study design in adult male CMT1A rats for 3 months, PXT3003, but not its dual components, resulted in improved performance in behavioral motor and sensory endpoints when compared to placebo. Unexpectedly, we observed only a marginally increased number of myelinated axons in nerves from PXT3003-treated CMT1A rats. However, in electrophysiology, motor latencies correlated with increased grip strength indicating a possible effect of PXT3003 on neuromuscular junctions (NMJs) and muscle fiber pathology. Indeed, PXT3003-treated CMT1A rats displayed an increased perimeter of individual NMJs and a larger number of functional NMJs. Moreover, muscles of PXT3003 CMT1A rats displayed less neurogenic atrophy and a shift toward fast contracting muscle fibers. We suggest that ameliorated motor function in PXT3003-treated CMT1A rats result from restored NMJ function and muscle innervation, independent from myelination.
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Affiliation(s)
- Thomas Prukop
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Institute of Clinical Pharmacology, University Medical Center Göttingen, Göttingen, Germany
| | - Stephanie Wernick
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | | | - David Ewers
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Karoline Jäger
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Julia Adam
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Lorenz Winter
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Susanne Quintes
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Lisa Linhoff
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Michael Bartl
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Dirk Czesnik
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Jana Zschüntzsch
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Jens Schmidt
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | | | | | | | | | | | - Markus H Schwab
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | | | | | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
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Ni Z, Vial F, Avram AV, Leodori G, Pajevic S, Basser PJ, Hallett M. Measuring conduction velocity distributions in peripheral nerves using neurophysiological techniques. Clin Neurophysiol 2020; 131:1581-1588. [PMID: 32417700 DOI: 10.1016/j.clinph.2020.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine how long it takes for neural impulses to travel along peripheral nerve fibers in living humans. METHODS A collision test was performed to measure the conduction velocity distribution of the ulnar nerve. Two stimuli at the distal and proximal sites were used to produce the collision. Compound muscle or nerve action potentials were recorded to perform the measurements on the motor or mixed nerve, respectively. Interstimulus interval was set at 1-5 ms. A quadri-pulse technique was used to measure the refractory period and calibrate the conduction time. RESULTS Compound muscle action potential produced by the proximal stimulation started to emerge at the interstimulus interval of about 1.5 ms and increased with the increment in interstimulus interval. Two groups of motor nerve fibers with different conduction velocities were identified. The mixed nerve showed a wider conduction velocity distribution with identification of more subgroups of nerve fibers than the motor nerve. CONCLUSIONS The conduction velocity distributions in high resolution on a peripheral motor and mixed nerve are different and this can be measured with the collision test. SIGNIFICANCE We provided ground truth data to verify the neuroimaging pipelines for the measurements of latency connectome in the peripheral nervous system.
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Affiliation(s)
- Zhen Ni
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States
| | - Felipe Vial
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States; Facultad de Medicina Clinica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Alexandru V Avram
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, United States
| | | | - Sinisa Pajevic
- Mathematical and Statistical Computing Laboratory, Center for Information Technology, National Institutes of Health, United States
| | - Peter J Basser
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States.
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States.
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Yue S, Yue Q, Hale T, Knecht A. Site-dependent thenar compound muscle action potential: Comparison between surface and needle recordings. J Back Musculoskelet Rehabil 2020; 32:841-845. [PMID: 30883332 DOI: 10.3233/bmr-181188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Within the thenar eminence, the median nerve innervates three muscles: abductor pollicis brevis (APB), flexor pollicis brevis (FPB), and opponens pollicis (OP). Of these muscles, APB was often considered as the sole contributor to the thenar compound muscle action potential (CMAP). OBJECTIVE To evaluate subcomponents of the thenar CMAP from the median nerve innervated muscles. METHODS Surface and needle CMAPs were recorded in normal human subjects from three recording sites: proximal (site-I), middle (site-II), and distal (site-III) aspects of the thenar eminence when the median nerve was activated at the wrist. RESULTS In the site-I and -II, both the surface and needle CMAPs shared many similar characteristics although the needle CMAPs were larger (∼ 5 folds) and briefer (∼ 60%, needle/surface duration). In addition, on the surface recording, the CMAP was larger (by ∼ 1.9 mV) when recorded from the site-I comparing to that of the site-II. In the site-III, the surface recordings registered a delayed (by ∼ 3.8 ms) CMAP. The muscle fiber action potential (MFAP) study suggested a predominant FPB contribution in the site-III. CONCLUSION The optimal recording site for APB derived thenar CMAP is the site-I and for FPB is the site-III. The CMAPs registered by the needle recordings are more robust than the surface ones.
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Affiliation(s)
- Sophie Yue
- College of Science, University of Notre Dame, Notre Dame, IN, USA
| | - Qing Yue
- Department of Communication Science and Disorders, Bloomsburg University of Pennsylvania, Bloomsburg, PA, USA
| | - Tyson Hale
- Department of Neurophysiology, Geisinger Health System, Danville, PA, USA
| | - Aaron Knecht
- Department of Neurophysiology, Geisinger Health System, Danville, PA, USA
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Sonoo M. Far-field potentials in the compound muscle action potential. Muscle Nerve 2019; 61:271-279. [PMID: 31650553 DOI: 10.1002/mus.26743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 10/12/2019] [Accepted: 10/18/2019] [Indexed: 11/09/2022]
Abstract
It has long been believed that the compound muscle action potential (CMAP) in motor-nerve conduction studies (MCSs) records the action potential beneath the active electrode over the muscle belly. However, recent studies have revealed the contribution of the reference electrode to the CMAP, most prominent in the tibial nerve, followed by the ulnar nerve. This "reference electrode potential" is recorded when the conventional reference electrode distal to the muscle belly is connected to a proximal reference. It must be a far-field potential (FFP) considering its distribution, although the precise mechanism of its generation has not been clarified. The conventional theory of termination of the action potential at the muscle-tendon junction is insufficient. Regarding the ulnar CMAP, interosseous muscles mostly contribute to the FFPs. New understanding of CMAP based on the FFP theory may provide new insights into the interpretation of MCSs and related techniques, including motor unit number estimation.
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Affiliation(s)
- Masahiro Sonoo
- Department of Neurology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
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12
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Choi A, Kwon NY, Kim K, Kim Y, Oh J, Oh HM, Park JH. Anatomical Localization of Motor Points of the Abductor Hallucis Muscle: A Cadaveric Study. Ann Rehabil Med 2017; 41:589-594. [PMID: 28971043 PMCID: PMC5608666 DOI: 10.5535/arm.2017.41.4.589] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/21/2016] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To identify the anatomical motor points of the abductor hallucis muscle in cadavers. METHODS Motor nerve branches to the abductor hallucis muscles were examined in eight Korean cadaver feet. The motor point was defined as the site where the intramuscular nerve penetrates the muscle belly. The reference line connects the metatarsal base of the hallux (H) to the medial tubercle of the calcaneus (C). The x coordinate was the horizontal distance from the motor point to the point where the perpendicular line from the navicular tuberosity crossed the reference line. The y coordinate was the perpendicular distance from the motor point to the navicular tuberosity. RESULTS Most of the medial plantar nerves to the abductor hallucis muscles divide into multiple branches before entering the muscles. One, two, and three motor branches were observed in 37.5%, 37.5%, and 25% of the feet, respectively. The ratios of the main motor point from the H with respect to the H-C line were: main motor point, 68.79%±5.69%; second motor point, 73.45%±3.25%. The mean x coordinate value from the main motor point was 0.65±0.49 cm. The mean value of the y coordinate was 1.43±0.35 cm. All of the motor points of the abductor hallucis were consistently found inferior and posterior to the navicular tuberosity. CONCLUSION This study identified accurate locations of anatomical motor points of the abductor hallucis muscle by means of cadaveric dissection, which can be helpful for electrophysiological studies in order to correctly diagnose the various neuropathies associated with tibial nerve components.
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Affiliation(s)
- Asayeon Choi
- Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Na Yeon Kwon
- Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Kyeongwon Kim
- Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | | | - Jeehae Oh
- Department of Rehabilitation Medicine, Eulji General Hospital, Seoul, Korea
| | - Hyun Mi Oh
- Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Joo Hyun Park
- Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Sanchez B, Pacheck A, Rutkove SB. Guidelines to electrode positioning for human and animal electrical impedance myography research. Sci Rep 2016; 6:32615. [PMID: 27585740 PMCID: PMC5009322 DOI: 10.1038/srep32615] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/10/2016] [Indexed: 12/14/2022] Open
Abstract
The positioning of electrodes in electrical impedance myography (EIM) is critical for accurately assessing disease progression and effectiveness of treatment. In human and animal trials for neuromuscular disorders, inconsistent electrode positioning adds errors to the muscle impedance. Despite its importance, how the reproducibility of resistance and reactance, the two parameters that define EIM, are affected by changes in electrode positioning remains unknown. In this paper, we present a novel approach founded on biophysical principles to study the reproducibility of resistance and reactance to electrode misplacements. The analytical framework presented allows the user to quantify a priori the effect on the muscle resistance and reactance using only one parameter: the uncertainty placing the electrodes. We also provide quantitative data on the precision needed to position the electrodes and the minimum muscle length needed to achieve a pre-specified EIM reproducibility. The results reported here are confirmed with finite element model simulations and measurements on five healthy subjects. Ultimately, our data can serve as normative values to enhance the reliability of EIM as a biomarker and facilitate comparability of future human and animal studies.
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Affiliation(s)
- Benjamin Sanchez
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
| | - Adam Pacheck
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
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Bhatt NK, Park AM, Al-Lozi M, Paniello RC. Compound Motor Action Potential Quantifies Recurrent Laryngeal Nerve Innervation in a Canine Model. Ann Otol Rhinol Laryngol 2016; 125:584-90. [DOI: 10.1177/0003489416637386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective: The compound motor action potential (CMAP) is the summated action potential from multiple muscle fibers activated by a single nerve impulse. The utility of laryngeal muscle CMAP for quantifying innervation following recurrent laryngeal nerve (RLN) injury was investigated. Method: In a series of 21 canine hemi-laryngeal preparations, RLNs were exposed and a stimulating electrode placed. Maximum CMAP amplitudes and area under the curve from the thyroarytenoid (TA) muscles were obtained at baseline and at 6 months following injury to the RLN. Injury mechanisms included crush, stretch, cautery, and complete transection with microsuture repair. Results: Prior to injury, baseline CMAP amplitudes and area under the curve were 15.81 mV and 15.49mVms, respectively. Six months following injury, CMAP amplitude and area under curve were 105.1% and 102.1% of baseline for stretch, 98.7% and 112.7% for crush, 93.3% and 114.3% for cautery. The CMAP amplitude and area under the curve in the transection/repair group had a 54.3% and 69.4% recovery, respectively, which were significantly different than baseline ( P < .01, P < .05). These values were correlated with vocal fold motion. Conclusion: The CMAP is a measure of vocal fold innervation. The technique could be further developed for clinical and experimental applications.
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Affiliation(s)
- Neel K. Bhatt
- Department of Otolaryngology - Head and Neck Surgery, Washington University, Saint Louis, MO, USA
| | - Andrea M. Park
- Department of Otolaryngology - Head and Neck Surgery, Washington University, Saint Louis, MO, USA
| | - Muhammad Al-Lozi
- Department of Neurology, Washington University, Saint Louis, MO, USA
| | - Randal C. Paniello
- Department of Otolaryngology - Head and Neck Surgery, Washington University, Saint Louis, MO, USA
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15
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Schilder JCM, van Dijk JG, Dressler D, Koelman JHTM, Marinus J, van Hilten JJ. Responsiveness to botulinum toxin type A in muscles of complex regional pain patients with tonic dystonia. J Neural Transm (Vienna) 2014; 121:761-7. [PMID: 24532257 DOI: 10.1007/s00702-014-1172-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 02/02/2014] [Indexed: 11/27/2022]
Abstract
Tonic dystonia of the limbs in complex regional pain syndrome (CRPS) is associated with considerable disability. Treatment options are scarce. Botulinum toxin (BoNT) is sometimes used, but the effect is often said to be disappointing. However, this notion stems from case reports and clinicians' opinions but has never been formally studied. We therefore investigated responsiveness to BoNT in CRPS patients with tonic dystonia. We injected the extensor digitorum brevis (EDB) muscle with BoNT-A in 17 patients with CRPS and tonic dystonia to compare the response between affected and unaffected legs. We also investigated the right legs of 17 healthy controls. Responsiveness was defined as a decrease of the amplitude of the compound muscle action potential (CMAP) of >20% from baseline 2 weeks after BoNT-A injection. We controlled for a temperature effect on BoNT efficacy by measuring skin temperature hourly directly above the EDB muscle in the first 2 weeks. CMAP amplitude decreased >20% after injection on the affected side in 16 of 17 CRPS patients, similar to the response in unaffected legs (12/13) or legs of controls (17/17). The degree of CMAP reduction was significantly smaller in patients than in controls (56.0 ± 22.3 vs. 70.6 ± 14.6%; p = 0.031). This may be due to a lower physical activity level and a greater difficulty to localize the EDB muscle properly in affected legs. The decrease in CMAP amplitude was not related to skin temperature. Contrary to the prevailing opinion, BoNT-A has a normal, although perhaps slightly lower efficacy in CRPS patients with dystonia.
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Affiliation(s)
- Johanna C M Schilder
- Department of Neurology and Clinical Neurophysiology, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands,
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Compound Motor Action Potential Interexaminer Variability in Photoguided Placement of the Recording Electrodes. J Clin Neurophysiol 2012; 29:256-9. [DOI: 10.1097/wnp.0b013e3182570f6e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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17
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Sonoo M, Kurokawa K, Higashihara M, Kurono H, Hokkoku K, Hatanaka Y, Shimizu T. Origin of far-field potentials in the ulnar compound muscle action potential. Muscle Nerve 2011; 43:671-8. [PMID: 21484826 DOI: 10.1002/mus.21931] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
INTRODUCTION The compound muscle action potential (CMAP) following ulnar nerve stimulation receives a considerable contribution from far-field potentials (FFPs), although their origin is not entirely clear. We investigated this issue using voluntary contractions. METHODS In 7 control subjects, we placed multiple recording electrodes over the motor points of ulnar-innervated muscles. We asked the subjects to perform a weak movement corresponding to the action of each muscle, and identified the single motor unit potentials (MUPs) from that muscle. We summed the MUPs from each individual muscle and reconstructed the CMAPs. RESULTS The reconstructed CMAPs coincided well with the actual ones. The N1, P1, and early N2 components of the FFPs were generated primarily by palmar, but also by dorsal, interosseous muscles. The abductor digiti minimi muscle usually generated positive-negative biphasic FFPs, and the negative FFP generated the late N2 component. CONCLUSIONS These results should prompt a revision of the theory of FFP generation.
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Affiliation(s)
- Masahiro Sonoo
- Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo 1738605, Japan.
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Keenan KG, Collins JD, Massey WV, Walters TJ, Gruszka HD. Coherence between surface electromyograms is influenced by electrode placement in hand muscles. J Neurosci Methods 2010; 195:10-4. [PMID: 21074555 DOI: 10.1016/j.jneumeth.2010.10.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/18/2010] [Accepted: 10/19/2010] [Indexed: 11/19/2022]
Abstract
We used multi-channel surface electromyograms (EMGs) to examine if electrode location influences coherence measures derived from pairs of EMGs recorded from two hand muscles during a pinch task. A linear probe of 16 electrodes was used to estimate the location of the innervation zone in first dorsal interosseous (FDI) and abductor pollicis brevis (APB). Four electrodes were then placed on the skin overlying each muscle and three bipolar electrode configurations were constructed with their center points directly over the innervation zone, and 15mm distal and proximal to the innervation zone. Ten subjects performed two force-matching tasks for 120s at 2N and 3.5N by pressing a force sensor held between the thumb and index finger. Coherence spectra were calculated from pairs of EMGs recorded from the two muscles. Maximal coherence from 1 to 15Hz and 16 to 32Hz was calculated at both force levels from the EMGs with electrodes centered over the innervation zones of FDI and APB. These values were compared to the maximal coherence from all other EMG comparisons across muscles recorded with electrodes that avoided the innervation zones. ANOVA revealed significant main effects only for electrode location, with a 58.1% increase (p=0.001) in maximal coherence for EMGs detected from pairs of electrodes that avoided the innervation zone (from 0.11±0.02 to 0.18±0.03; mean±95% confidence interval). These results indicate that electrode location relative to the innervation zone influences EMG-EMG coherence and should be carefully considered when placing EMG electrodes on hand muscles.
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Affiliation(s)
- Kevin G Keenan
- Neuromechanics Lab, Dept. of Human Movement Sciences,College of Health Sciences, University of Wisconsin-Milwaukee, 1600 E. Hartford Ave, Milwaukee, WI 53201, USA.
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Higashihara M, Sonoo M, Imafuku I, Ugawa Y, Tsuji S. Origin of ulnar compound muscle action potential investigated in patients with ulnar neuropathy at the wrist. Muscle Nerve 2010; 41:704-6. [DOI: 10.1002/mus.21620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kong X, Lesser EA, Gozani SN. Repeatability of nerve conduction measurements derived entirely by computer methods. Biomed Eng Online 2009; 8:33. [PMID: 19895683 PMCID: PMC2777171 DOI: 10.1186/1475-925x-8-33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 11/06/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nerve conduction studies are an objective, quantitative, and reproducible measure of peripheral nerve function and are widely used in the diagnosis of neuropathies. The purpose of this study is to determine the reliability of nerve conduction parameters derived entirely from computer based data acquisition and waveform cursor assignments and to quantify the relative contributions of test variability sources. METHODS Thirty volunteers, some with symptoms suggestive of neuropathies; of these, 29 completed the study. The median, ulnar, deep peroneal, posterior tibial, and sural nerves were evaluated bilaterally at two test sessions 3-7 days apart. Within each session, nerves were tested twice within 10 minutes. The analyzed nerve conduction parameters include motor latencies, motor conduction velocity (CV), compound muscle action potential (CMAP) amplitude, F-wave latencies (minimum, mean and maximum), sensory peak latency (DSL), sensory CV, and sensory nerve action potential (SNAP) amplitude. The primary outcome measure is variance component analysis and the corresponding coefficient of variation (CoV). The between-session-test variance is the sum of within-session variance and between-session variance, quantifying the total variation between test sessions. Additional statistical measures include the intraclass correlation coefficient (ICC) and relative interval variation (RIV). RESULTS Motor and sensory latencies, CV and F-wave latency parameters have low between-session-test CoVs, ranging from 4.2% to 9.8%. Amplitude parameters have a higher between-session-test CoVs in the range of 15.6--19.8%. Between-test CoVs are about 30--80% lower than between-session CoVs with the exception of F-wave latency parameters. Between-test ICC values are 0.96 or above for all parameters. Between-session ICC ranges from 0.98 for F-wave latency to 0.77 for sural sensory CV. All latency-related between-session ICCs have a value 0.83 or above. The RIVs are the tightest for F-wave latency parameters and widest for CMAP amplitude parameters. Repeatability in a sub-group of subjects with more severe symptom grades follows the same trend as the overall study population without substantial quantitative differences. CONCLUSION The study demonstrates the high repeatability of nerve conduction parameters acquired by modern electrodiagnostic instruments using computer based waveform cursor assignment. The reliability is comparable to benchmark studies in which the nerve conduction measurements were performed manually in controlled multi-center clinical trials. Furthermore, the ranking of reliability, whereby F-wave latencies have the best reproducibility and amplitudes the worst, is also consistent with the benchmark studies.
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Affiliation(s)
- Xuan Kong
- NeuroMetrix, Inc 62 Fourth Avenue, Waltham, MA, USA.
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Evidence of Potential Averaging over the Finite Surface of a Bioelectric Surface Electrode. Ann Biomed Eng 2009; 37:1141-51. [PMID: 19319681 DOI: 10.1007/s10439-009-9680-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 03/16/2009] [Indexed: 10/21/2022]
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22
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Botter A, Merletti R, Minetto MA. Pulse charge and not waveform affects M-wave properties during progressive motor unit activation. J Electromyogr Kinesiol 2008; 19:564-73. [PMID: 18455437 DOI: 10.1016/j.jelekin.2008.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 03/21/2008] [Accepted: 03/21/2008] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to investigate changes in experimentally recorded M-waves with progressive motor unit (MU) activation induced by transcutaneous electrical stimulation with different pulse waveforms. In 10 subjects, surface electromyographic signals were detected with a linear electrode array during electrically elicited contractions of the biceps brachii muscle. Three different monophasic waveforms of 304-micros duration were applied to the stimulation electrode on the main muscle motor point: triangular, square, and sinusoidal. For each waveform, increasing stimulation current intensities were applied in 10 s (frequency: 20 Hz). It was found that: (a) the degree of MU activation, as indicated by M-wave average rectified value, was a function of the injected charge and not of the stimulation waveform, and (b) MUs tended to be recruited in order of increasing conduction velocity with increasing charge of transcutaneous stimulation. Moreover, the subjects reported lower discomfort during the contractions elicited by the triangular waveform with respect to the others. Since subject tolerance to the stimulation protocol must be considered as important as MU recruitment in determining the effectiveness of neuromuscular electrical stimulation (NMES), we suggest that both charge and waveform of the stimulation pulses should be considered relevant parameters for optimizing NMES protocols.
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Affiliation(s)
- A Botter
- Laboratory for Engineering of the Neuromuscular System (LISiN), Department of Electronics, Polytechnic of Turin, Turin, Italy
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Latronico N, Bertolini G, Guarneri B, Botteri M, Peli E, Andreoletti S, Bera P, Luciani D, Nardella A, Vittorielli E, Simini B, Candiani A. Simplified electrophysiological evaluation of peripheral nerves in critically ill patients: the Italian multi-centre CRIMYNE study. Crit Care 2007; 11:R11. [PMID: 17254336 PMCID: PMC2151880 DOI: 10.1186/cc5671] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 12/17/2006] [Accepted: 01/25/2007] [Indexed: 11/27/2022] Open
Abstract
Introduction Critical illness myopathy and/or neuropathy (CRIMYNE) is frequent in intensive care unit (ICU) patients. Although complete electrophysiological tests of peripheral nerves and muscles are essential to diagnose it, they are time-consuming, precluding extensive use in daily ICU practice. We evaluated whether a simplified electrophysiological investigation of only two nerves could be used as an alternative to complete electrophysiological tests. Methods In this prospective, multi-centre study, 92 ICU patients were subjected to unilateral daily measurements of the action potential amplitude of the sural and peroneal nerves (compound muscle action potential [CMAP]). After the first ten days, complete electrophysiological investigations were carried out weekly until ICU discharge or death. At hospital discharge, complete neurological and electrophysiological investigations were performed. Results Electrophysiological signs of CRIMYNE occurred in 28 patients (30.4%, 95% confidence interval [CI] 21.9% to 40.4%). A unilateral peroneal CMAP reduction of more than two standard deviations of normal value showed the best combination of sensitivity (100%) and specificity (67%) in diagnosing CRIMYNE. All patients developed the electrophysiological signs of CRIMYNE within 13 days of ICU admission. Median time from ICU admission to CRIMYNE was six days (95% CI five to nine days). In 10 patients, the amplitude of the nerve action potential dropped progressively over a median of 3.0 days, and in 18 patients it dropped abruptly within 24 hours. Multi-organ failure occurred in 21 patients (22.8%, 95% CI 15.4% to 32.4%) and was strongly associated with CRIMYNE (odds ratio 4.58, 95% CI 1.64 to 12.81). Six patients with CRIMYNE died: three in the ICU and three after ICU discharge. Hospital mortality was similar in patients with and without CRIMYNE (21.4% and 17.2%; p = 0.771). At ICU discharge, electrophysiological signs of CRIMYNE persisted in 18 (64.3%) of 28 patients. At hospital discharge, diagnoses in the 15 survivors were critical illness myopathy (CIM) in six cases, critical illness polyneuropathy (CIP) in four, combined CIP and CIM in three, and undetermined in two. Conclusion A peroneal CMAP reduction below two standard deviations of normal value accurately identifies patients with CRIMYNE. These should have full neurological and neurophysiological evaluations before discharge from the acute hospital.
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Affiliation(s)
- Nicola Latronico
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
- GiViTI, Gruppo Italiano per la Valutazione degli Interventi in Terapia Intensiva Steering Committee, Aldo e Cele Daccò Clinical Research Centre Mario Negri Institute, Villa Camozzi – 24020 Ranica (BG), Italy
| | - Guido Bertolini
- Laboratory of Clinical Epidemiology, Aldo e Cele Daccò Clinical Research Centre Mario Negri Institute, Villa Camozzi – 24020 Ranica (BG), Italy
- GiViTI, Gruppo Italiano per la Valutazione degli Interventi in Terapia Intensiva Steering Committee, Villa Camozzi – 24020 Ranica (BG), Italy
| | - Bruno Guarneri
- Department of Clinical Neurophysiology, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Marco Botteri
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Elena Peli
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Serena Andreoletti
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Paola Bera
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Davide Luciani
- Laboratory of Clinical Epidemiology, Aldo e Cele Daccò Clinical Research Centre Mario Negri Institute, Villa Camozzi – 24020 Ranica (BG), Italy
| | - Anna Nardella
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Elena Vittorielli
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
| | - Bruno Simini
- GiViTI, Gruppo Italiano per la Valutazione degli Interventi in Terapia Intensiva Steering Committee, Villa Camozzi – 24020 Ranica (BG), Italy
| | - Andrea Candiani
- Department of Anesthesiology-Intensive Care, University of Brescia, Spedali Civili, Piazzale Ospedali Civili, 1 – 25123 Brescia, Italy
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Nandedkar SD, Barkhaus PE. Contribution of reference electrode to the compound muscle action potential. Muscle Nerve 2007; 36:87-92. [PMID: 17455266 DOI: 10.1002/mus.20798] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In compound muscle action potential (CMAP) recording, the contribution by the reference electrode is considered to be much smaller than that of the active electrode. We tested this assumption by making quantitative measurements of the signals recorded individually by the active and reference electrodes. In the thenar (median nerve) and extensor digitorum brevis (peroneal nerve) muscles, the reference electrode did contribute less. In the hypothenar muscle (ulnar nerve), however, the signals recorded by active and reference electrodes were of similar amplitude. In tibial nerve conduction studies (NCS), the CMAP from the abductor hallucis (AH) muscle was recorded mainly by the reference electrode; the large-amplitude signal recorded by the reference electrode is attributed to volume-conducted activity from other muscles stimulated during the study. The onset latency of the potential recorded by the active and reference electrodes was similar despite significantly different distances from the stimulating site. Hence, the merits of using anatomic landmarks for defining the distal stimulation site are assessed. When the reference electrode makes a large contribution, the CMAP amplitude may not decrease commensurate with any wasting of the muscle under the active recording electrode, and the need to use another muscle for recording the CMAP for that nerve should be considered.
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Jabre JF, Salzsieder BT, Gnemi KE. Criterion validity of the NC-stat automated nerve conduction measurement instrument. Physiol Meas 2006; 28:95-104. [PMID: 17151423 DOI: 10.1088/0967-3334/28/1/009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose of this study is to assess the criterion validity of peroneal and posterior tibial nerve conduction measurements obtained with the NC-stat system. Sixty patients referred to the Boston VA EMG laboratory were enrolled. Each subject had a full study of the lower extremity performed using traditional EMG equipment prior to obtaining the NC-stat measurements. These included peroneal and posterior tibial distal motor latency (DML), amplitude (AMP) and F-wave latency (FLAT) measurements. Excellent criterion validity was demonstrated for the peroneal and posterior tibial FLATs and the peroneal AMP. Acceptable criterion validity was identified in the peroneal DML and the posterior tibial AMP. The validity of the posterior tibial DML could not be demonstrated. With the exception of the peroneal DML, criterion validity was maintained in a sub-group analysis of the 50% most abnormal parameter values. The comparability of NCS performed with the NC-stat and in traditional settings has been demonstrated for motor studies of the median and ulnar nerves in previous studies. This study shows that the technology used by the NC-stat for studying the peroneal and posterior tibial nerves compares favorably as well with that obtained with traditional EMG equipment used under neurologist supervision.
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Affiliation(s)
- Joe F Jabre
- Neurology Service, Boston VA Healthcare System, Boston, MA, USA.
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26
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Chapter 13 Neurography – motor and sensory nerve conduction studies. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1567-4231(09)70123-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Ruys-Van Oeyen AEWM, van Dijk JG. Repetitive nerve stimulation of the nasalis muscle: technique and normal values. Muscle Nerve 2002; 26:279-82. [PMID: 12210394 DOI: 10.1002/mus.10201] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A technique of repetitive nerve stimulation of the facial nerve with recording from the nasalis and orbicularis oculi muscles was developed and tested in 15 healthy subjects. Quality criteria were that the stimulus artifact should return to baseline before the onset of the compound muscle action potential (CMAP), and that the CMAP should begin with a negative phase, be biphasic in shape, and have an amplitude of over 1 mV. Repetitive nerve stimulation was only performed if all four criteria were met, which was the case in all 15 subjects for the nasalis muscle, but in only 5 subjects for the orbicularis oculi muscle. The largest observed decrement was 9% in area. Reptitive nerve stimulation of the nasalis muscle is thus feasible, but its diagnostic utility remains to be established in patients with disorders of neuromuscular transmission.
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Affiliation(s)
- Astrid E W M Ruys-Van Oeyen
- Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, The Netherlands
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Phongsamart G, Wertsch JJ, Ferdjallah M, King JC, Foster DT. Effect of reference electrode position on the compound muscle action potential (CMAP) onset latency. Muscle Nerve 2002; 25:816-21. [PMID: 12115969 DOI: 10.1002/mus.10119] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Compound muscle action potential (CMAP) onset latency is interpreted to reflect the arrival time at the muscle of impulses in the fastest-conducting motor nerve fiber. However, we have observed that the position of the reference or indifferent electrode (E2) affects CMAP onset latency. Motor nerve conduction studies (NCS) of the median, ulnar, and deep ulnar motor (DUM) nerves on 20 normal hands were performed using both traditional bipolar and experimental monopolar (referenced to the contralateral hand) montages. As the position of E2 was altered, the CMAP onset latency varied 0.1-0.5 ms for the median NCS, 0.1-0.3 ms for the ulnar NCS, and 0.1-1.5 ms for the DUM NCS. This study demonstrates that E2 recorded potentials are significant and vary with positioning, affecting motor onset latency. This has implications both for reference values and the physiologic interpretation of the CMAP waveform.
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Affiliation(s)
- Gulapar Phongsamart
- Medical College of Wisconsin, Zablocki VA Medical Center, Department of Physical Medicine and Rehabilitation, 5000 W. National Avenue, Milwaukee, Wisconsin 53295, USA
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Bromberg MB, Fries TJ, Forshew DA, Tandan R. Electrophysiologic endpoint measures in a multicenter ALS drug trial. J Neurol Sci 2001; 184:51-5. [PMID: 11231032 DOI: 10.1016/s0022-510x(00)00489-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We report the analysis of a battery of secondary electrophysiologic measurements to assess the progression of amyotrophic lateral sclerosis (ALS) in a two center, six month, double-blind, three arm trial comparing branched chain amino acids to L-threonine with pyridoxal 5-phosphate to placebo. The endpoint measurements were chosen to separately assess the effects of lower motor neuron loss and collateral reinnervation. For tests of inter-center reliability, we found no differences that could not be readily explained by variations in electrophysiologic testing techniques. Since the drug study was negative for the primary endpoint measure (muscle strength), we combined data from both centers and the three treatment arms. For measures of progression, all measures changed in the expected direction during the 6 months of the trial. We conclude that a battery of electrophysiologic measures can be used in a multicenter ALS drug trial to provide information on changes in lower motor neuron numbers and the effects of collateral reinnervation.
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Affiliation(s)
- M B Bromberg
- Department of Neurology, The University of Utah, Salt Lake City, UT, USA.
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van Dijk JG, van der Hoeven BJ, van der Hoeven H. Repetitive nerve stimulation: effects of recording site and the nature of 'pseudofacilitation'. Clin Neurophysiol 2000; 111:1411-9. [PMID: 10904222 DOI: 10.1016/s1388-2457(00)00331-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To describe changes in the waveform of the compound muscle action potential (CMAP) during repetitive nerve stimulation for various recording sites. METHODS Responses to trains of 10 stimuli given at 0.1, 1, 3, 5, 10 and 30 Hz to the ulnar nerve were recorded simultaneously from 8 hand sites in 15 healthy subjects. Percentile changes of amplitude, duration and area of both negative and positive phases were analyzed. RESULTS Duration consistently decreased during the trains. At 30 Hz, the mean amplitude of the negative phase increased on 5 sites but decreased on 3. Area consistently decreased, but least for hypothenar sites. Repeated stimulation causes an alteration in the waveform of the CMAP that consists of 4 elements: (1) shorter duration; (2) changed amplitude of the negative phase (up or down); (3) merging of bifid peaks; (4) changes were more pronounced for positive than negative phases. CONCLUSIONS As the term 'pseudofacilitation' implies an increase in amplitude, it is often not appropriate. Increased muscle fiber conduction velocity can explain most of the waveform alterations. Movement and shortening of muscles may play additional roles. Consequences for diagnostic yield await a comparison with disease groups.
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Affiliation(s)
- J G van Dijk
- Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, The, Leiden, Netherlands.
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