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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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Luo X, Wang S, Sanchez B. Modeling and simulation of needle electrical impedance myography in nonhomogeneous isotropic skeletal muscle. IEEE JOURNAL OF ELECTROMAGNETICS, RF AND MICROWAVES IN MEDICINE AND BIOLOGY 2022; 6:103-110. [PMID: 35434441 PMCID: PMC9012450 DOI: 10.1109/jerm.2021.3091515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Objective Needle electrical impedance myography (EIM) is a recently developed technique for neuromuscular evaluation. Despite its preliminary successful clinical application, further understanding is needed to aid interpreting EIM outcomes in nonhomogeneous skeletal muscle measurements. Methods The framework presented models needle EIM measurements in a bidomain isotropic model. Finite element method (FEM) simulations verify the validity of our model predictions studying two cases: a spherical volume surrounded by tissue and a two-layered tissue. Results Our models show that EIM is influenced by the vicinity of tissue with different electrical properties. The apparent resistance, reactance and phase relative errors between our theoretical predictions and FEM simulations in the spherical volume case study are ≤0.2%, ≤1.2% and ≤1.0%, respectively. For the two-layered tissue model case study, the relative errors are ≤2%. Conclusions We propose a bio-physics driven analytical framework describing needle EIM measurements in a nonhomogeneous bidomain tissue model. Clinical impact Our theoretical predictions may lead to new ways for interpreting needle EIM data in neuromuscular diseases that cause compositional changes in muscle content, e.g. connective tissue deposition within the muscle. These changes will manifest themselves by changing the electric properties of the conductor media and will impact impedance values.
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Affiliation(s)
- Xuesong Luo
- Department of Automation Science and Electric Engineering, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100083, China,Sanchez Research Lab, Department of Electrical and Computer Engineering, Sorenson Molecular Biotechnology Building, 36 South Wasatch Drive, University of Utah, Salt Lake City, UT 84112, USA
| | - Shaoping Wang
- Department of Automation Science and Electric Engineering, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100083, China
| | - Benjamin Sanchez
- Sanchez Research Lab, Department of Electrical and Computer Engineering, Sorenson Molecular Biotechnology Building, 36 South Wasatch Drive, University of Utah, Salt Lake City, UT 84112, USA
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Marquardt RJ, Levin KH. Electrodiagnostic Assessment of Radiculopathies. Neurol Clin 2021; 39:983-995. [PMID: 34602222 DOI: 10.1016/j.ncl.2021.06.011] [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: 11/17/2022]
Abstract
This article discusses the electrodiagnostic assessment of radiculopathy. Relevant anatomy initially is reviewed followed by discussion surrounding the approach to nerve conduction studies and needle electrode examination when it comes to radiculopathy evaluation. Pitfalls of the electrodiagnosis versus clinical diagnosis of radiculopathy and the definitions of acute versus chronic, and active versus inactive, are reviewed.
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Affiliation(s)
- Robert J Marquardt
- Neuromuscular Center, Department of Neurology, Cleveland Clinic, 9500 Euclid Avenue, Desk S90, Cleveland, OH 44195, USA
| | - Kerry H Levin
- Neuromuscular Center, Department of Neurology, Cleveland Clinic, 9500 Euclid Avenue, Desk S90, Cleveland, OH 44195, USA.
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Cardoner MMDM, Kwon H, Pulido HVG, Nagy J, Rutkove S, Sanchez B. Modeling and Reproducibility of Twin Concentric Electrical Impedance Myography. IEEE Trans Biomed Eng 2021; 68:3068-3077. [PMID: 33661730 DOI: 10.1109/tbme.2021.3063724] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Electrical impedance myography (EIM) is a recent technology to assess muscle health. As of today, the clinical application of EIM has been applied only to evaluate muscle condition using non-invasive surface electrodes in contact with the skin; however, intermediate tissues at the recording site introduce confounding artifacts which reduce the technique's performance as a biomarker of neuromuscular disorders (NMD). Here, we develop and test in humans a new approach using two concentric needles for intramuscular EIM recordings. METHODS First, we study the recording characteristics of dual concentric needle EIM via analytical models and finite element models (FEMs). Next, the validity of the models is verified by performing experiments on saline and agar phantoms. Finally, 8 subjects with various neuromuscular diseases were studied measuring tibialis anterior, biceps, deltoid, adductor pollicis brevis, first dorsal interosseous and flexor carpi radialis muscles. RESULTS Analytical and FEM simulations are in good agreement with a maximum experimental discrepancy 8% and 9% using gauge needles 26 and 30, respectively. The inter-session reproducibility, as measured by the intraclass correlation coefficients for all muscles studied, was 0.926, which is comparable or exceeds the reproducibility of other well-established electrophysiological tests to assess muscle health. CONCLUSION The reproducibility of the technique support future clinical validation of needle EIM for assessment of disease status, either as part of standard patient care or as biomarker measure in clinical trials. SIGNIFICANCE Needle EIM has the potential of becoming a valuable diagnostic tool to evaluate NMD in adult population.
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Christiansen L, Larsen MN, Madsen MJ, Grey MJ, Nielsen JB, Lundbye-Jensen J. Long-term motor skill training with individually adjusted progressive difficulty enhances learning and promotes corticospinal plasticity. Sci Rep 2020; 10:15588. [PMID: 32973251 PMCID: PMC7518278 DOI: 10.1038/s41598-020-72139-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 08/21/2020] [Indexed: 12/16/2022] Open
Abstract
Motor skill acquisition depends on central nervous plasticity. However, behavioural determinants leading to long lasting corticospinal plasticity and motor expertise remain unexplored. Here we investigate behavioural and electrophysiological effects of individually tailored progressive practice during long-term motor skill training. Two groups of participants practiced a visuomotor task requiring precise control of the right digiti minimi for 6 weeks. One group trained with constant task difficulty, while the other group trained with progressively increasing task difficulty, i.e. continuously adjusted to their individual skill level. Compared to constant practice, progressive practice resulted in a two-fold greater performance at an advanced task level and associated increases in corticospinal excitability. Differences were maintained 8 days later, whereas both groups demonstrated equal retention 14 months later. We demonstrate that progressive practice enhances motor skill learning and promotes corticospinal plasticity. These findings underline the importance of continuously challenging patients and athletes to promote neural plasticity, skilled performance, and recovery.
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Affiliation(s)
- Lasse Christiansen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark. .,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Amager and Hvidovre, Hvidovre, Denmark.
| | - Malte Nejst Larsen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Mads Just Madsen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Amager and Hvidovre, Hvidovre, Denmark
| | - Michael James Grey
- School of Health Sciences, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Jens Bo Nielsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Lundbye-Jensen
- Department of Nutrition Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
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Follow-up in transthyretin familial amyloid polyneuropathy: Useful investigations. J Neurol Sci 2020; 413:116776. [PMID: 32203746 DOI: 10.1016/j.jns.2020.116776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 11/21/2022]
Abstract
Patients with transthyretin amyloid polyneuropathy (TTR-FAP) and asymptomatic mutation-carriers have to be regularly followed-up in order to identify disease progression and the time point for starting or modifying therapy. In this case series we describe the potential suitability of different variables as progression markers. We retrospectively analyzed the follow-up charts of 10 TTR-FAP patients. Clinical examination included the Neuropathy Impairment Score of Lower Limb (NIS-LL), temperature perception thresholds, nerve conduction and autonomic function tests. The NIS-LL had the greatest value for a sensitive and correct follow-up for all TTR-FAP stages. All other examinations provided useful additional information but they were either less suited for advanced TTR-FAP, or had a higher test-retest variability. The results of this study provide preliminary evidence that a good clinical investigation is mandatory in TTR-FAP follow-up. Simple neuropathy scores like the NIS-LL might be as useful as technical investigations for TTR-FAP follow-up.
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Delianides C, Tyler D, Pinault G, Ansari R, Triolo R. Implanted High Density Cuff Electrodes Functionally Activate Human Tibial and Peroneal Motor Units Without Chronic Detriment to Peripheral Nerve Health. Neuromodulation 2020; 23:754-762. [PMID: 32189421 DOI: 10.1111/ner.13110] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Peripheral nerve stimulation via multi-contact nerve cuff electrodes (NCEs) has proved effective in restoring function to individuals with lower-extremity paralysis. This study investigates clinical measures of nerve health over one year post-implantation of a composite flat-interface nerve electrode (C-FINE) on the tibial and peroneal nerves above the knee in a human volunteer. This represents the first deployment of a novel NCE on new neural targets in a uniquely challenging location prone to prolonged externally applied forces, making acute and chronic postoperative observation critical. MATERIALS AND METHODS A 27-year-old man with an incomplete spinal cord injury (AIS C) at the C3 to C4 level received eight-contact C-FINEs bilaterally on the tibial and peroneal nerves, proximal to the knee. Access to four contacts per cuff exhibiting the most desirable responses was externalized via temporary percutaneous leads. Percutaneous leads were later removed, with contacts generating the best dorsiflexion (two of four) and plantar flexion (one of four) reconnected to a permanently implanted pulse generator. For 13 months post-implantation, nerve health and cuff performance were assessed through motor nerve conduction velocity (MNCV) studies, clinical needle electromyography, compound motor action potential (CMAP), sensory nerve action potential (SNAP), stimulation-evoked tetanic moment collection, and lower-limb circumference measurements. RESULTS Tibial and peroneal MNCVs remained stable bilaterally above 40 m/sec, with CMAPs increased or stable after six months. SNAPs remained stable across all measurements. CMAP initial charge thresholds remained below 50 nC, with minimal changes to muscle recruitment order in three of four externalized contacts per cuff. Peak tetanic moments remained stable, with bilateral increases in thigh and calf circumferences of 5% and 14% over one year. CONCLUSIONS Above-knee tibial and peroneal NCEs can restore stimulated ankle-joint function without chronic nerve health detriments. Alongside previous femoral nerve data, this study demonstrates the ability of NCEs to enhance lower-extremity function with limited neuromuscular impact.
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Affiliation(s)
- Christopher Delianides
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Dustin Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Gilles Pinault
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA.,Department of Surgery, Case Western Reserve University, Cleveland, OH, USA
| | - Rahila Ansari
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA.,Department of Neurology, Case Western Reserve University, Cleveland, OH, USA
| | - Ronald Triolo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
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Stålberg E, van Dijk H, Falck B, Kimura J, Neuwirth C, Pitt M, Podnar S, Rubin DI, Rutkove S, Sanders DB, Sonoo M, Tankisi H, Zwarts M. Standards for quantification of EMG and neurography. Clin Neurophysiol 2019; 130:1688-1729. [DOI: 10.1016/j.clinph.2019.05.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/07/2019] [Accepted: 05/09/2019] [Indexed: 12/11/2022]
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Application of electrophysiological measures in spinal cord injury clinical trials: a narrative review. Spinal Cord 2019; 57:909-923. [PMID: 31337870 DOI: 10.1038/s41393-019-0331-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 01/05/2023]
Abstract
STUDY DESIGN Narrative review. OBJECTIVES To discuss how electrophysiology may contribute to future clinical trials in spinal cord injury (SCI) in terms of: (1) improvement of SCI diagnosis, patient stratification and determination of exclusion criteria; (2) the assessment of adverse events; and (3) detection of therapeutic effects following an intervention. METHODS An international expert panel for electrophysiological measures in SCI searched and discussed the literature focused on the topic. RESULTS Electrophysiology represents a valid method to detect, track, and quantify readouts of nerve functions including signal conduction, e.g., evoked potentials testing long spinal tracts, and neural processing, e.g., reflex testing. Furthermore, electrophysiological measures can predict functional outcomes and thereby guide rehabilitation programs and therapeutic interventions for clinical studies. CONCLUSION Objective and quantitative measures of sensory, motor, and autonomic function based on electrophysiological techniques are promising tools to inform and improve future SCI trials. Complementing clinical outcome measures, electrophysiological recordings can improve the SCI diagnosis and patient stratification, as well as the detection of both beneficial and adverse events. Specifically composed electrophysiological measures can be used to characterize the topography and completeness of SCI and reveal neuronal integrity below the lesion, a prerequisite for the success of any interventional trial. Further validation of electrophysiological tools with regard to their validity, reliability, and sensitivity are needed in order to become routinely applied in clinical SCI trials.
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Kodaira M, Kodama S, Kamijo Y, Kaneko T, Sekijima Y. Muscle training-induced bilateral brachial plexopathy in an adolescent with sporadic hereditary neuropathy with liability to pressure palsies. Brain Behav 2017; 7:e00783. [PMID: 28948078 PMCID: PMC5607547 DOI: 10.1002/brb3.783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/13/2017] [Accepted: 06/26/2017] [Indexed: 01/08/2023] Open
Abstract
There have been few studies regarding physical training-induced peripheral nerve dysfunction in patients with hereditary neuropathy with liability to pressure palsies (HNPP), with the exception of soldiers that trained intensively. Here, we report a 15-year-old boy without family history of HNPP who developed bilateral painless brachial plexopathy following short-term barbell and plank training during a school baseball club activity. Muscle training-induced painless brachial plexopathy could be an initial symptom and may be underdiagnosed in adolescents with sporadic HNPP.
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Affiliation(s)
- Minori Kodaira
- Department of Medicine (Neurology and Rheumatology)Shinshu University School of MedicineMatsumotoJapan
| | - Satoshi Kodama
- Department of Medicine (Neurology and Rheumatology)Shinshu University School of MedicineMatsumotoJapan
| | - Yui Kamijo
- Department of NeurologySaku Central Hospital Advanced Care CenterSakuJapan
| | - Tomoki Kaneko
- Department of RadiologyShinshu University School of MedicineMatsumotoJapan
| | - Yoshiki Sekijima
- Department of Medicine (Neurology and Rheumatology)Shinshu University School of MedicineMatsumotoJapan
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Lanza G, Kosac A, Trajkovic G, Whittaker RG. Nerve Conduction Studies as a Measure of Disease Progression: Objectivity or Illusion? J Neuromuscul Dis 2017; 4:209-215. [PMID: 28869485 DOI: 10.3233/jnd-170243] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Clinical nerve conduction studies (NCS) are often used as a secondary outcome measure in therapeutic trials, but show a high degree of inter-trial variability even when technical factors known to affect the recorded responses are minimised. This raises the intriguing possibility that some of the observed variability may reflect true changes in nerve activity. OBJECTIVES Our aim was determine how much variability these factors might produce, and how this might affect the results of commonly used neuropathy rating scales. METHODS A standardised protocol was repeated over forty consecutive trials by the same operators in two healthy subjects. The protocol included recordings that shared either a stimulating or a recording electrode position, such that changes due to electrode position could be excluded, and hand temperature was closely controlled. RESULTS Despite controlling for inter-operator differences, electrode position, and hand temperature, the variability in sensory nerve action potential (SNAP) amplitude was extremely high (Range 23 μV, CoV = 10.7-18.8). This variability was greater than the change in amplitude needed to move a subject from point 0 to point 4 on the CMT neuropathy rating scale. Neither temperature or electrode position accounted for all of this variability, suggesting that additional as yet unidentified factors are responsible. CONCLUSION Even under closely controlled conditions and sophisticated laboratory methods, test-to-test variability can be significant. The factors responsible for this variability may be difficult to control, limiting the utility of single nerve recordings as a trial outcome measure.
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Affiliation(s)
- Giuseppe Lanza
- Department of Neurology I.C., "Oasi" Institute for Research on Mental Retardation and Brain Aging (I.R.C.C.S.), Troina (EN), Italy
| | - Ana Kosac
- Clinic of Neurology and Psychiatry for Children and Youth, Belgrade, Serbia
| | - Goran Trajkovic
- Institute of Medical Statistics and Informatics, School of Medicine, University of Belgrade, Belgrade, Serbia
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Troni W, Melillo F, Bertolotto A, Malucchi S, Capobianco M, Sperli F, Di Sapio A. Normative Values for Intertrial Variability of Motor Responses to Nerve Root and Transcranial Stimulation: A Condition for Follow-Up Studies in Individual Subjects. PLoS One 2016; 11:e0155268. [PMID: 27182973 PMCID: PMC4868303 DOI: 10.1371/journal.pone.0155268] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 04/11/2016] [Indexed: 11/19/2022] Open
Abstract
Objective Intertrial variability (ITV) of motor responses to peripheral (CMAP) and transcranial (MEP) stimulation prevents their use in follow-up studies. Our purpose was to develop strategies to reduce and measure CMAP and MEP ITV to guide long-term monitoring of conduction slowing and conduction failure of peripheral and central motor pathway in the individual patient. Methods Maximal compound muscle action potentials to High Voltage Electrical Stimulation (HVES) of lumbo-sacral nerve roots (r-CMAP) and activated, averaged motor evoked potentials (MEPs) to Transcranial Magnetic Stimulation (TMS) using double cone coil were recorded from 10 proximal and distal muscle districts of lower limbs. The procedure was repeated twice, 1–2 days apart, in 30 subjects, including healthy volunteers and clinically stable multiple sclerosis patients, using constant stimulating and recording sites and adopting a standardized procedure of voluntary activation. ITV for latency and area indexes and for the ratio between MEP and r-CMAP areas (a-Ratio) was expressed as Relative Intertrial Variation (RIV, 5th-95th percentile). As an inverse correlation between the size of area and ITV was found, raw ITV values were normalized as a function of area to make them comparable with one another. Results All RIV values for latencies were significantly below the optimum threshold of ± 10%, with the exception of r-CMAP latencies recorded from Vastus Lateralis muscle. RIVs for a-Ratio, the most important index of central conduction failure, ranged from a maximum of -25.3% to +32.2% (Vastus Medialis) to a minimum of -15.0% to + 17.4% (Flexor Hallucis Brevis). Conclusions The described procedure represents an effort to lower as much as possible variability of motor responses in serial recording; the reported ITV normative values are the necessary premise to detect significant changes of motor conduction slowing and failure in the individual patient in follow-up studies.
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Affiliation(s)
- Walter Troni
- Service of Neurology and Clinical Neurophysiology, Clinica Fornaca di Sessant, Turin, Italy
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
- * E-mail:
| | - Federica Melillo
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
| | - Antonio Bertolotto
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
| | - Simona Malucchi
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
| | - Marco Capobianco
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
| | - Francesca Sperli
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
| | - Alessia Di Sapio
- 2nd Department of Neurology, Multiple Sclerosis Regional Centre, San Luigi Gonzaga Hospital, Orbassano, Italy
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Schuhfried O, Herceg M, Pieber K, Paternostro-Sluga T. Interrater Repeatability of Motor Nerve Conduction Velocity of the Ulnar Nerve. Am J Phys Med Rehabil 2016; 96:45-49. [PMID: 27149598 DOI: 10.1097/phm.0000000000000530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The purpose of this study was to obtain data on interrater repeatability of the motor nerve conduction velocity (NCV) of the ulnar nerve of different segments, ulnar distal motor latency (DML), and compound muscle action potential (CMAP) amplitudes. DESIGN Twenty-four healthy volunteers were examined in consecutive order. Ulnar motor NCV of different segments, ulnar DML, and CMAP amplitudes were determined. Based on a randomization list of various combinations and sequences, 1 of 3 examiners performed the first measurement. A second examiner repeated the evaluation within half an hour. RESULTS There were no significant differences between the first and second measurements for all parameters. For the ulnar motor NCV of the different segments, the intraclass correlation coefficient (ICC) ranged from 0.38 to 0.51, and the coefficient of repeatability (CR) ranged from 8.0 to 11.6 m/s. For the ulnar DML, the ICC was 0.44, and the CR was 0.49 millisecond. For the CMAP amplitudes at the different stimulation sites, the ICC ranged from 0.53 to 0.76, and the CR ranged from 1.5 to 2.3 mV. CONCLUSIONS A moderate amount of interrater variability of the ulnar motor NCV must be taken into account. Compared with the CMAP amplitudes, the interrater repeatability of the ulnar motor NCV is poorer.
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Affiliation(s)
- Othmar Schuhfried
- From the Department of Physical Medicine and Rehabilitation, Medical University of Vienna General Hospital of Vienna (OS, MH, KP); and Institute of Physical Medicine and Rehabilitation, Donauspital (TP-S), Vienna, Austria
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Dale AM, Evanoff B, Al-Lozi M. Reply: To PMID 25463687. PM R 2015; 7:551. [PMID: 25983198 DOI: 10.1016/j.pmrj.2015.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/13/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Ann Marie Dale
- Division of General Medical Sciences, Washington University School of Medicine, St Louis, MO(∗)(†)
| | - Bradley Evanoff
- Division of General Medical Sciences, Washington University School of Medicine, St Louis, MO(∗)(†)
| | - Muhammad Al-Lozi
- Department of Neurology, Washington University School of Medicine, St Louis, MO(‡)
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Dale AM, Agboola F, Yun A, Zeringue A, Al-Lozi MT, Evanoff B. Comparison of automated versus traditional nerve conduction study methods for median nerve testing in a general worker population. PM R 2015; 7:276-82. [PMID: 25463687 PMCID: PMC4372480 DOI: 10.1016/j.pmrj.2014.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/10/2014] [Accepted: 10/06/2014] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the validity of automated nerve conduction studies compared to traditional electrodiagnostic studies (EDS) for testing median nerve abnormalities in a working population. DESIGN Agreement study and sensitivity investigation from 2 devices. SETTING Field research testing laboratory. PARTICIPANTS Active workers from several industries participating in a longitudinal study of carpal tunnel syndrome. METHODS Sixty-two subjects received bilateral median and ulnar nerve conduction testing across the wrist with a traditional device and the NC-stat automated device. We compared the intermethod agreement of analogous measurements. MAIN OUTCOME MEASUREMENT Nerve conduction study parameters. RESULTS Median motor and sensory latency comparisons showed excellent agreement (intraclass correlation coefficients 0.85 and 0.80, respectively). Areas under the receiver operating characteristic curves were 0.97 and 0.96, respectively, using the optimal thresholds of 4.4-millisecond median motor latency (sensitivity 100%, specificity 86%) and 3.9-millisecond median sensory latency (sensitivity 100%, specificity 87%). Ulnar nerve testing results were less favorable. CONCLUSION The automated NC-stat device showed excellent agreement with traditional EDS for detecting median nerve conduction abnormalities in a general population of workers, suggesting that this automated nerve conduction device can be used to ascertain research case definitions of carpal tunnel syndrome in population health studies. Further study is needed to determine optimal thresholds for defining median conduction abnormalities in populations that are not seeking clinical care.
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Affiliation(s)
- Ann Marie Dale
- Divisions of General Medical Sciences and Neurology, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8005, St. Louis, MO 63110(∗).
| | - Folasade Agboola
- Divisions of General Medical Sciences and Neurology, Washington University School of Medicine, St. Louis, MO; and Saint Louis University School of Public Health, St Louis, MO(†)
| | - Amber Yun
- Saint Louis University School of Public Health, St Louis, MO; and Washington State Hospital Association, Seattle, WA(‡)
| | - Angelique Zeringue
- Divisions of General Medical Sciences and Neurology, Washington University School of Medicine, St. Louis, MO; and Saint Louis University School of Public Health, St Louis, MO(§)
| | - Muhammed T Al-Lozi
- Divisions of General Medical Sciences and Neurology, Washington University School of Medicine, St. Louis, MO(‖)
| | - Bradley Evanoff
- Divisions of General Medical Sciences and Neurology, Washington University School of Medicine, St. Louis, MO(¶)
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Spontaneous Temporal Changes and Variability of Peripheral Nerve Conduction Analyzed Using a Random Effects Model. J Clin Neurophysiol 2014; 31:387-91. [DOI: 10.1097/wnp.0000000000000088] [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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Pan H, Lin J, Chen N, Jian F, Zhang Z, Ding Z, Wang Y, Nobrega JAM, Kohara N, Cui L, Kimura J. Normative data of F-wave measures in China. Clin Neurophysiol 2013; 124:183-9. [DOI: 10.1016/j.clinph.2012.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 06/07/2012] [Accepted: 06/08/2012] [Indexed: 11/24/2022]
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Wang FC, Massart N, Kaux JF, Bouquiaux O. [F-waves]. Rev Neurol (Paris) 2011; 167:938-44. [PMID: 22100326 DOI: 10.1016/j.neurol.2011.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 06/02/2011] [Accepted: 06/17/2011] [Indexed: 11/26/2022]
Abstract
F-waves result from the discharge of the motoneurons following their antidromic activation. The F-wave appears, as an indirect (the F-wave latency decreases when the stimulation site moves away from the muscular detection) and late response (occurring after the M response). In practice, the most useful parameter is the F-wave minimal latency, provided that at least seven distinct F-waves are evoked. When the analysis is relative either to the controlateral side, or to a former examination, this parameter is one of most sensitive in electroneuromyography. F-wave evocation implies conduction along the entire peripheral nervous system, and particularly its proximal part, which is not investigated by nervous trunks conduction velocity studies. Thus, F wave study is the most useful in plexopathies and polyradiculonevritis. In the early phase of Guillain-Barré syndrome, their absence may be the unique sign indicative of proximal conduction blocks.
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Affiliation(s)
- F C Wang
- Service de médecine physique et de l'appareil locomoteur, CHU Sart Tilman, B35, 4000 Liège, Belgique.
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Reproducibility of the CMAP scan. J Electromyogr Kinesiol 2010; 21:433-7. [PMID: 21134767 DOI: 10.1016/j.jelekin.2010.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/19/2010] [Accepted: 11/12/2010] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION The CMAP scan is a surface EMG method based on the successive activation of motor units. It provides information about reinnervation processes, the number of functional motor units and nerve excitability. The CMAP scan has potential value as a follow-up tool in monitoring disease progression, recovery or aging of the peripheral nerves. In this study, we assessed its interobserver and different-day reproducibility. METHODS Two investigators recorded CMAP scans in ten healthy subjects, each on two different days. Intraclass correlation coefficients (ICCs) and coefficients of variation (CoVs) were calculated for the parameters extracted from the CMAP scan. RESULTS All CMAP scan parameters had a good different day (ICCs >0.8 and CoVs <15%) and interobserver reproducibility (ICCs >0.7 and CoVs ≤ 15%). Different-day reproducibility was better than interobserver reproducibility. CONCLUSION CMAP scan test-retest variability is small, suggesting that as a follow-up tool it may be sensitive to fairly small (patho)physiological changes in the studied variables.
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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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Rajabally YA, Beri S, Bankart J. Electrophysiological markers of large fibre sensory neuropathy: a study of sensory and motor conduction parameters. Eur J Neurol 2009; 16:1053-9. [DOI: 10.1111/j.1468-1331.2009.02651.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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