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| 2. |
- Barkhaus, Paul E., et al.
(författare)
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Revisiting the compound muscle action potential (CMAP)
- 2024
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Ingår i: Clinical Neurophysiology Practice. - : Elsevier. - 2467-981X. ; 9, s. 176-200
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Tidskriftsartikel (refereegranskat)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. CO 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 3. |
- Dengler, Reinhard, et al.
(författare)
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AANEM - IFCN glossary of terms in neuromuscular electrodiagnostic medicine and ultrasound
- 2020
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Ingår i: Clinical Neurophysiology. - : ELSEVIER IRELAND LTD. - 1388-2457 .- 1872-8952. ; 131:7, s. 1662-1663
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Forskningsöversikt (refereegranskat)abstract
- Modern neuromuscular electrodiagnosis (EDX) and neuromuscular ultrasound (NMUS) require a universal language for effective communication in clinical practice and research and, in particular, for teaching young colleagues. Therefore, the AANEM and the IFCN have decided to publish a joint glossary as they feel the need for an updated terminology to support educational activities in neuromuscular EDX and NMUS in all parts of the world. In addition NMUS has been rapidly progressing over the last years and is now widely used in the diagnosis of disorders of nerve and muscle in conjunction with EDX. This glossary has been developed by experts in the field of neuromuscular EDX and NMUS on behalf of the AANEM and the IFCN and has been agreed upon by electronic communication between January and November 2019. It is based on the glossaries of the AANEM from 2015 and of the IFCN from 1999. The EDX and NMUS terms and the explanatory illustrations have been updated and supplemented where necessary. The result is a comprehensive glossary of terms covering all fields of neuromuscular EDX and NMUS. It serves as a standard reference for clinical practice, education and research worldwide. (C) 2020 the American Association of Neuromuscular & Electrodiagnostic Medicine and the International Federation of Clinical Neurophysiology.
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| 4. |
- Dengler, Reinhard, et al.
(författare)
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AANEM - IFCN Glossary of Terms in Neuromuscular Electrodiagnostic Medicine and Ultrasound
- 2020
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Ingår i: Muscle and Nerve. - : WILEY. - 0148-639X .- 1097-4598. ; 62:1, s. 10-12
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Modern neuromuscular electrodiagnosis (EDX) and neuromuscular ultrasound (NMUS) require a universal language for effective communication in clinical practice and research and, in particular, for teaching young colleagues. Therefore, the AANEM and the IFCN have decided to publish a joint glossary as they feel the need for an updated terminology to support educational activities in neuromuscular EDX and NMUS in all parts of the world. In addition NMUS has been rapidly progressing over the last years and is now widely used in the diagnosis of disorders of nerve and muscle in conjunction with EDX. This glossary has been developed by experts in the field of neuromuscular EDX and NMUS on behalf of the AANEM and the IFCN and has been agreed upon by electronic communication between January and November 2019. It is based on the glossaries of the AANEM from 2015 and of the IFCN from 1999. The EDX and NMUS terms and the explanatory illustrations have been updated and supplemented where necessary. The result is a comprehensive glossary of terms covering all fields of neuromuscular EDX and NMUS. It serves as a standard reference for clinical practice, education and research worldwide.
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| 5. |
- Kouyoumdjian, Joao A., et al.
(författare)
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Concentric needle jitter in stimulated frontalis in 20 healthy subjects
- 2012
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 45:2, s. 276-278
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Tidskriftsartikel (refereegranskat)abstract
- Normative data for jitter parameters using a disposable concentric needle have been presented in a few studies. Jitter, expressed as the mean consecutive difference (MCD), was measured in the frontalis muscle in 20 subjects by percutaneous bar stimulation of the temporal nerve branch. The mean MCD for individual studies (20) and for all potentials (600) were 16.05 +/- 2.73 mu s and 16.05 +/- 5.96 mu s, respectively. The suggested limit for mean MCD is 22 mu s and for outliers is 28 mu s.
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| 6. |
- Kouyoumdjian, Joao Aris, et al.
(författare)
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Concentric needle jitter on stimulated frontalis and extensor digitorum in 20 myasthenia gravis patients
- 2011
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 44:6, s. 912-918
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Our objective was to study jitter parameters using a concentric needle electrode (CNE) in the extensor digitorum (ED) and frontalis (FR) muscles. Methods: Twenty myasthenia gravis (MG) patients, mean age 44.5 years, were studied. Percutaneous (FR) and intramuscular needle (ED) stimulation approaches were used. Jitter was expressed as the mean consecutive difference (MCD). The filter settings were from 1000 HZ to 10 kHZ. Results: Abnormal MCD was found in 85% for both ED and FR and in 90% when combining the two muscles. An abnormal percentage of outliers was found in 90% for ED and 85% for FR. The mean MCD did not show a difference for ED and FR, but the percentage of outliers and blocking were higher in FR. Abnormality was found in 93.7% (generalized) and in 75% (ocular) of MG cases. For ED outliers abnormality was greater than the MCD. Conclusion: CNE jitter is reliable for investigation of MG, although borderline findings should be judged with caution.
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| 7. |
- Kouyoumdjian, Joao Aris, et al.
(författare)
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Concentric needle jitter on stimulated Orbicularis Oculi in 50 healthy subjects
- 2011
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Ingår i: Clinical Neurophysiology. - : Elsevier BV. - 1388-2457 .- 1872-8952. ; 122:3, s. 617-622
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to estimate the jitter parameters in healthy controls in stimulated Orbicularis Oculi (OOc) muscle using concentric needle electrode (CNE). Methods: Fifty healthy subjects, 13 males and 37 females (21-56 years, mean age of 38 +/- 9.2 years) were studied. The zygomatic branch of facial nerve was stimulated with a bar electrode. Jitter was expressed as the mean consecutive difference (MCD). Filter settings 1000 Hz-10 kHz. Results: The mean MCD from individual studies (n = 50, Gaussian distribution) was 21.5 +/- 1.99 mu s (median = 21 mu s), ranging from 17.8 to 26 mu s (upper limit, 97.5%, 25.5 mu s). The mean and median MCD from all potentials (n = 1500, non-Gaussian distribution) were 21.6 and 21 mu s, ranging from 7.1 to 39 mu s (upper limit, 97.5%, 33.4 mu s). Conclusions: Suggested practical limits in the OOc for mean MCD was 26 mu s and for outliers 34 mu s. Significance: Stimulation jitter recordings with CNE could be used in practice but borderline findings should be judged with great caution until larger database obtained with uniform setting available.
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| 8. |
- Kouyoumdjian, Joao A., et al.
(författare)
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Concentric needle jitter on voluntary activated frontalis in 20 healthy subjects
- 2013
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 47:3, s. 440-442
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Normative data for jitter parameters using a disposable concentric needle have been described in a few studies. Methods: Jitter, expressed as the mean consecutive difference (MCD), was measured in the frontalis muscle in 20 subjects by voluntary contraction. Results: Mean MCD for individual studies (20, Gaussian), all potentials (400, non-Gaussian), and 18th highest value (20, Gaussian) were 19.9 +/- 2.9 s, 19.9 +/- 6.6 s, and 26.9 +/- 4.4 s, respectively. Conclusion: The suggested upper normal limit for mean MCD is 26 s and for outliers is 36 s.
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| 9. |
- Kouyoumdjian, Joao Aris, et al.
(författare)
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Concentric needle single fiber electromyography : Comparative jitter on voluntary-activated and stimulated Extensor Digitorum Communis
- 2008
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Ingår i: Clinical Neurophysiology. - : Elsevier BV. - 1388-2457 .- 1872-8952. ; 119:7, s. 1614-1618
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare the jitter values in voluntarily activated (v-CNE) and stimulated (s-CNE) techniques for Extensor Digitorum Communis muscle using a disposable concentric needle electrode (CNE). Quantifying jitter using a CNE in conjunction with a stimulated technique has not been reported previously. Methods: Forty-one normal subjects were studied, 15 male and 26 female with a mean age of 34.1 +/- 10.7 years (19-55). The jitter values were expressed as the mean consecutive difference (MCD) of 20 analyzed potential pairs using v-CNE and 30 isolated potentials using s-CNE. Results: The mean MCD (n = 41) was 23.0 +/- 2.8 mu s for v-CNE and 18.2 +/- 2.2 mu s for s-CNE. The mean jitter of all recorded potentials was 22.9 +/- 6.7 mu s for v-CNE (n = 820) and 18.3 +/- 5.2 mu s for s-CNE (n = 1230). Upper limits for the 18th (v-CNE) and 27th highest (s-CNE) MCD were 38.9 and 30 mu s, respectively (95% confidence limit). The jitter decrease in s-CNE compared to v-CNE was 1:0.79. Conclusions: Our findings of the jitter values using CNE were similar to other published reports using the voluntarily activated technique; however, these are the first described for the stimulated technique using CNE. Significance: The present study confirms that CNE can be used for the stimulated jitter acquisition and measurement, although certain precautions must be taken regarding signal quality, e.g., observing minimal summation.
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| 10. |
- Kouyoumdjian, João Aris, et al.
(författare)
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Reference jitter values for concentric needle electrodes in voluntarily activated extensor digitorum communis and orbicularis oculi muscles.
- 2008
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 37:6, s. 694-699
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to estimate normal jitter in voluntarily activated extensor digitorum communis (EDC) and orbicularis oculi (OOc) muscles using a disposable concentric needle electrode (CNE). The EDC of 67 normal subjects (22 males and 45 females, mean age 35.5 ± 10.2 years) and the OOc of 50 normal subjects (13 males and 37 females, mean age 37.9 ± 9.6 years) were studied. Jitter values were expressed as the mean consecutive difference (MCD) of 20 potential pairs. The mean MCD for EDC was 23.6 ± 3.1 µs (upper 95% confidence limit [CL]: 29.7 µs). The mean MCD of all potential pairs (n = 1340) was 23.5 ± 7.3 µs (95% CL: 38.2 µs). The mean MCD for the 18th highest value was 31.4 ± 4.9 µs (95% CL: 41.2 µs). The mean MCD for OOc was 24.7 ± 3.1 µs (95% CL: 31.0 µs). The mean MCD of all potential pairs (n = 1000) was 24.7 ± 7.1 µs (95% CL: 39.0 µs). The mean MCD for the 18th highest value was 32.7 ± 4.1 µs (95% CL: 40.9 µs). Our reported CNE jitter values obtained during voluntary activation represent the largest series currently available. The suggested practical limit in the EDC for mean MCD was 30 µs and for outliers was 42 µs, and in the OOc for mean MCD was 31 µs and 41 µs for outliers. The present study confirms that CNE can be used to assess jitter values, although certain precautions must be taken.
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