The Experts below are selected from a list of 20571 Experts worldwide ranked by ideXlab platform
Hatice Tankisi - One of the best experts on this subject based on the ideXlab platform.
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Advancing disease monitoring of amyotrophic lateral sclerosis with the compound Muscle Action Potential scan
'Elsevier BV', 2021Co-Authors: Bthm Sleutjes, Hatice Tankisi, Anna Bystrup Jacobsen, Gorkem N. Sirin, Emre A. Oge, Robert D. Henderson, P.a. Van Doorn, Leonard H. Van Den Berg, Ruben P.a. Van EijkAbstract:Objective: To determine which compound Muscle Action Potential (CMAP) scan-derived electrophysiological markers are most sensitive for monitoring disease progression in amyotrophic lateral sclerosis (ALS), and whether they hold value for clinical trials. Methods: We used four independent patient cohorts to assess longitudinal patterns of a comprehensive set of electrophysiological markers including their association with the ALS functional rating scale (ALSFRS-R). Results were translated to trial sample size requirements. Results: In 65 patients, 225 thenar CMAP scan recordings were obtained. Electrophysiological markers showed extensive variation in their longitudinal trajectories. Expressed as standard deviations per month, motor unit number estimation (MUNE) values declined by 0.09 (CI 0.07–0.12), D50, a measure that quantifies CMAP scan discontinuities, declined by 0.09 (CI 0.06–0.13) and maximum CMAP by 0.05 (CI 0.03–0.08). ALSFRS-R declined fastest (0.12, CI 0.08 – 0.15), however the between-patient variability was larger compared to electrophysiological markers, resulting in larger sample sizes. MUNE reduced the sample size by 19.1% (n = 388 vs n = 314) for a 6-month study compared to the ALSFRS-R. Conclusions: CMAP scan-derived markers show promise in monitoring disease progression in ALS patients, where MUNE may be its most suitable derivate. Significance: MUNE may increase clinical trial efficiency compared to clinical endpoints.
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motor unit number index and compound Muscle Action Potential amplitude
Clinical Neurophysiology, 2019Co-Authors: H Bostock, A B Jacobsen, Hatice TankisiAbstract:Abstract Objectives MUNIX (motor unit number index), derived from the compound Muscle Action Potential (CMAP) and surface EMG interference pattern (SIP) has become popular as a substitute for motor unit number estimation (MUNE). This study was undertaken to determine why, in recent recordings from amyotrophic lateral sclerosis (ALS) patients and healthy controls, we found that MUNIX values resembled CMAP amplitudes more closely than MUNE values. Methods The relationship between MUNIX and CMAP and SIP amplitudes was investigated by a theoretical analysis and by reanalysing the data from the previous study. Results Theory indicates that when motor unit Potentials overlap extensively, information about motor unit size and number is lost, and MUNIX depends only on CMAP area and power. Accordingly, MUNIX values were found to be sensitive to changes in CMAP amplitude but insensitive to changes in SIP amplitude. The reproducibility of MUNIX measurements in healthy controls was found to depend almost entirely on correlation with CMAP properties. Conclusions MUNIX gives misleading information about motor unit numbers in healthy controls, and provides little information about loss of motor units in ALS patients beyond that given by simple CMAP amplitude measurements. Significance MUNIX should not be interpreted as a MUNE method.
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correlation between compound Muscle Action Potential amplitude and duration in axonal and demyelinating polyneuropathy
Clinical Neurophysiology, 2012Co-Authors: Hatice Tankisi, Marit Otto, Kirsten Pugdahl, Birger Johnsen, Anders FuglsangfrederiksenAbstract:Abstract Objective To get a better understanding of pathophysiology in polyneuropathies (PNPs) by correlating compound Muscle Action Potential (CMAP) amplitude with duration. Methods A total of 145 motor nerve conduction studies (MNCS) in 53 axonal and 132 MNCS in 45 demyelinating PNPs were analyzed. Peroneal and tibial MNCS were done by surface stimulation while for median and ulnar nerves near nerve or surface stimulations were used. CMAP amplitude and duration were compared in axonal and demyelination PNPs. Relationships between amplitude and duration of distally and proximally evoked CMAP were examined using regression analysis. Results CMAP amplitude was lower and duration was increased in all examined nerves in demyelinating PNPs than in axonal PNPs. In demyelinating PNPs, an inverse linear correlation between amplitude and duration was seen in distally and proximally evoked CMAP in all examined nerves. In axonal PNPs, there was no correlation in any of the nerves neither in distally nor in proximally evoked CMAP. Conclusions Distal CMAP duration and the relationship between CMAP amplitude and duration show supplementary electrodiagnostic Potential in demyelinating PNPs. Significance More knowledge about the relation between amplitude and duration in axonal lesions and demyelination may help to reveal the pathophysiology in PNPs. Significant correlation between amplitude and duration in demyelination may suggest that the severe decrease in amplitude in demyelinating PNPs is probably due to the increase in duration secondary to temporal dispersion.
Ping Zhou - One of the best experts on this subject based on the ideXlab platform.
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motor unit number estimation of human abductor hallucis from a compound Muscle Action Potential scan
Muscle & Nerve, 2018Co-Authors: Ya Zong, Cliff S Klein, Ping ZhouAbstract:INTRODUCTION This study performed motor unit number estimation (MUNE) of the abductor hallucis (AH) Muscle from 16 healthy control participants on the basis of the compound Muscle Action Potential (CMAP) scan. METHODS Muscle responses to electrical stimuli ranging from subthreshold to supramaximal intensity were recorded, and MUNE was determined from a model of the responses (MScanFit program). RESULTS The average CMAP amplitude and MUNE of the AH for the right and left sides combined were 19.6 ± 0.75 mV and 127 ± 5 (mean ± SE), respectively. DISCUSSION Findings of the study provide useful information about the motor unit number of the AH. Muscle Nerve 58: 735-737, 2018.
Erik Stalberg - One of the best experts on this subject based on the ideXlab platform.
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motor unit number index munix and compound Muscle Action Potential amplitude a reappraisal
Clinical Neurophysiology, 2019Co-Authors: Sanjeev D. Nandedkar, Paul E. Barkhaus, Erik StalbergAbstract:Motor unit number index (MUNIX) and compound Muscle Action Potential amplitude : A reappraisal
Sanjeev D. Nandedkar - One of the best experts on this subject based on the ideXlab platform.
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motor unit number index munix and compound Muscle Action Potential amplitude a reappraisal
Clinical Neurophysiology, 2019Co-Authors: Sanjeev D. Nandedkar, Paul E. Barkhaus, Erik StalbergAbstract:Motor unit number index (MUNIX) and compound Muscle Action Potential amplitude : A reappraisal
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Contribution of reference electrode to the compound Muscle Action Potential
Muscle & Nerve, 2007Co-Authors: Sanjeev D. Nandedkar, Paul E. BarkhausAbstract: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. Muscle Nerve, 2007
Guillaume Nicolas - One of the best experts on this subject based on the ideXlab platform.
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a european multicentre reappraisal of distal compound Muscle Action Potential duration in chronic inflammatory demyelinating polyneuropathy
European Journal of Neurology, 2012Co-Authors: Yusuf A Rajabally, J Lagarde, Julien Cassereau, Karine Viala, E Fournier, Guillaume NicolasAbstract:Background: The electrodiagnostic value of distal compound Muscle Action Potential duration (DCMAPD) has been studied rarely in chronic inflammatory demyelinating polyneuropathy (CIDP). Cut-offs proposed have not been widely evaluated. The influence of low-cut EMG filter settings ≤ 10 Hz as used in Europe is uncertain. Methods: We retrospectively reviewed records of 110 patients with typical, treatment-responsive CIDP, from Leicester, U.K., Paris and Angers, France. All fulfilled revised European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) clinical and electrodiagnostic criteria for typical CIDP (2010), before consideration of DCMAPD prolongation. Results were compared with those of 110 controls with chronic sensory/sensory-motor axonal neuropathy. We constructed receiver operating characteristic (ROC) curves for each nerve and derived cut-offs for DCMAPD prolongation, offering specificity of ≥ 98% vs. controls. Results: DCMAPD was significantly greater in all nerves for CIDP patients, compared with controls (P < 0.001). ROC curves allowed derivation of cut-offs of sensitivities ranging from 27.1% (ulnar nerve) to 60% (tibial nerve). Using these cut-offs to define DCMAPD prolongation in any studied motor nerve offered a sensitivity of 69.1% for CIDP and specificity of 97.3% vs. controls. Conclusion: Cut-offs for DCMAPD are dependent on EMG filter settings. DCMAPD prolongation in any motor nerve, using our derived cut-offs, represents a sensitive and specific marker of CIDP in patients studied with EMG equipment with low-cut filter settings ≤ 10 Hz. Appropriate use of this parameter appears an essential criterion to consider in assessing suspected CIDP, which may be helpful in limiting extensiveness and duration of electrophysiological testing, thereby reducing patient discomfort.
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value of distal compound Muscle Action Potential duration prolongation in acute inflammatory demyelinating polyneuropathy a european perspective
Muscle & Nerve, 2011Co-Authors: Yusuf A Rajabally, Guillaume NicolasAbstract:Introduction: The value of distal compound Muscle Action Potential duration (DCMAPD) has not been widely studied in acute inflammatory demyelinating polyneuropathy (AIDP) with electromyography (EMG) equipment at low-cut filter settings <10 Hz, as used in Europe. Methods: We retrospectively reviewed the records of 40 patients with AIDP and 40 controls with axonal neuropathy, from Leicester, UK, and Angers, France. Results: The best combination of sensitivity/specificity for AIDP using DCMAPD prolongation in any one nerve was offered by cut-offs from two other studies (sensitivity: 90% and 87.5%, respectively; specificity: 92.5% for both). Independent DCMAPD prolongation in any one nerve was better than, or equivalent to, other criteria. Conclusions: DCMAPD prolongation in any one nerve, at cut-offs suggested by prior studies, represents a sensitive and specific marker to aid/simplify electrodiagnosis of AIDP in patients studied with EMG equipment with low-cut filter settings of <10 Hz. Muscle Nerve, 2011
