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Wessel N, Kim JS, Joung BY, Ko YG, Dischl D, Gapelyuk A, Lee YH, Kim KW, Park JW, Landmesser U. Magnetocardiography at rest predicts cardiac death in patients with acute chest pain. Front Cardiovasc Med 2023; 10:1258890. [PMID: 38155993 PMCID: PMC10752986 DOI: 10.3389/fcvm.2023.1258890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/30/2023] [Indexed: 12/30/2023] Open
Abstract
Introduction Sudden cardiac arrest is a major cause of morbidity and mortality worldwide and remains a major public health problem for which better non-invasive prediction tools are needed. Primary preventive therapies, such as implantable cardioverter defibrillators, are not personalized and not predictive. Most of these devices do not deliver life-saving therapy during their lifetime. The individual relationship between fatal arrhythmias and cardiac function abnormalities in predicting cardiac death risk has rarely been explored. Methods We retrospectively analyzed the measurements at rest for 191 patients with acute chest pain (ACP) magnetocardiographically. Our recently introduced analyses are able to detect inhomogeneities of the depolarization and repolarization. Moreover, electrically silent phenomena-intracellular ionic currents as well as vortex currents-can be measured and quantified. All included ACP patients were recruited in 2009 at Yonsei University Hospital and were followed up until 2022. Results During half of the follow-up period (6.5 years), 11 patients died. Out of all the included nine clinical, eight magnetocardiographical, and nine newly introduced magnetoionographical parameters we tested in this study, three parameters revealed themselves to be outstanding at predicting death: heart rate-corrected QT (QTc) prolongation, depression of repolarization current IKr + IKs, and serum creatinine (all significant in Cox regression, p < 0.05). They clearly predicted cardiac death over the 6.5 years duration (sensitivity 90.9%, specificity 85.6%, negative predictive accuracy 99.4%). Cardiac death risk was more than ninefold higher in patients with low repolarization reserve and QTc prolongation in comparison with the remaining patients with ACP (p < 0.001). The non-parametric Kaplan-Meier statistics estimated significantly lower survival functions from their lifetime data (p < 0.001). Discussion To the best of our knowledge, these are the first data linking magnetocardiographical and magnetoionographical parameters and subsequent significant fatal events in people, suggesting structural and functional components to clinical life-threatening ventricular arrhythmogenesis. The findings support investigation of new prevention strategies and herald those new non-invasive techniques as complementary risk stratification tools.
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Affiliation(s)
- N. Wessel
- Department of Human Medicine, MSB Medical School Berlin GmbH, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Physics, Humboldt Universität zu Berlin, Berlin, Germany
| | - J. S. Kim
- Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - B. Y. Joung
- Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Y. G. Ko
- Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - D. Dischl
- Deutsches Herzzentrum der Charité, Department of Cardiology, Angiology and Intensive Care Medicine, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - A. Gapelyuk
- Department of Physics, Humboldt Universität zu Berlin, Berlin, Germany
| | - Y. H. Lee
- Center for Biosignals, KRISS Korea Research Institute of Standards and Science, Daejeon, Republic of Korea
| | - K. W. Kim
- Center for Biosignals, KRISS Korea Research Institute of Standards and Science, Daejeon, Republic of Korea
| | - J. W. Park
- Deutsches Herzzentrum der Charité, Department of Cardiology, Angiology and Intensive Care Medicine, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - U. Landmesser
- Deutsches Herzzentrum der Charité, Department of Cardiology, Angiology and Intensive Care Medicine, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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Wang Y, Zhao ZG, Chai Z, Fang JC, Chen M. Electromagnetic field and cardiovascular diseases: A state-of-the-art review of diagnostic, therapeutic, and predictive values. FASEB J 2023; 37:e23142. [PMID: 37650634 DOI: 10.1096/fj.202300201rr] [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: 02/04/2023] [Revised: 07/20/2023] [Accepted: 08/02/2023] [Indexed: 09/01/2023]
Abstract
Despite encouraging advances in early diagnosis and treatment, cardiovascular diseases (CVDs) remained a leading cause of morbidity and mortality worldwide. Increasing evidence has shown that the electromagnetic field (EMF) influences many biological processes, which has attracted much attention for its potential therapeutic and diagnostic modalities in multiple diseases, such as musculoskeletal disorders and neurodegenerative diseases. Nonionizing EMF has been studied as a therapeutic or diagnostic tool in CVDs. In this review, we summarize the current literature ranging from in vitro to clinical studies focusing on the therapeutic potential (external EMF) and diagnostic potential (internal EMF generated from the heart) of EMF in CVDs. First, we provided an overview of the therapeutic potential of EMF and associated mechanisms in the context of CVDs, including cardiac arrhythmia, myocardial ischemia, atherosclerosis, and hypertension. Furthermore, we investigated the diagnostic and predictive value of magnetocardiography in CVDs. Finally, we discussed the critical steps necessary to translate this promising approach into clinical practice.
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Affiliation(s)
- Yan Wang
- Laboratory of Heart Valve Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhen-Gang Zhao
- Laboratory of Heart Valve Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zheng Chai
- Laboratory of Heart Valve Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jian-Cheng Fang
- School of Instrumentation Science and Opto-Electronics Engineering, Beihang University, Beijing, China
| | - Mao Chen
- Laboratory of Heart Valve Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Zhang Z, He A, Xu Z, Yang K, Kong X. Neuromuscular Magnetic Field Measurement Based on Superconducting Bio-Sensors. MICROMACHINES 2023; 14:1768. [PMID: 37763931 PMCID: PMC10535156 DOI: 10.3390/mi14091768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/08/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023]
Abstract
These years, disease-causing and disabling diseases have caused great concern. Neurological musculoskeletal disorders are diverse and affect people of a wide range of ages. And the lack of comprehensive diagnostic methods places a huge burden on healthcare systems and social economies. In this paper, the current status of clinical research on neuromuscular diseases is introduced, and the advantages of magnetic field measurement compared with clinical diagnostic methods are illustrated. A comprehensive description of the related technology of superconducting quantum interference devices (SQUIDs), magnetic field detection noise suppression scheme, the development trend of the sensor detection system, and the application and model establishment of the neuromuscular magnetic field is also given in this paper. The current research and development trends worldwide are compared simultaneously, and finally the conclusions and outlook are put forward. Based on the description of the existing literature and the ideas of other researchers, the next development trends and my own research ideas are presented in this paper, that is, starting from the establishment of a neuromuscular model, combining medical and industrial work, designing a sensor system that meets clinical needs, and laying the foundation for the clinical application of a bio-magnetic system. This review promotes a combination between medicine and industry, and guides researchers on considering the challenges of sensor development in terms of clinical needs. In addition, in this paper, the development trends are described, including the establishment of the model, the clinical demand for sensors, and the challenges of system development so as to give certain guidance to researchers.
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Affiliation(s)
- Zhidan Zhang
- The Institute for Future Wireless Research (iFWR), Ningbo University, Ningbo 315211, China; (Z.Z.); (A.H.); (K.Y.)
- The Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
| | - Anran He
- The Institute for Future Wireless Research (iFWR), Ningbo University, Ningbo 315211, China; (Z.Z.); (A.H.); (K.Y.)
- The Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
| | - Zihan Xu
- The Institute for Future Wireless Research (iFWR), Ningbo University, Ningbo 315211, China; (Z.Z.); (A.H.); (K.Y.)
- The Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
| | - Kun Yang
- The Institute for Future Wireless Research (iFWR), Ningbo University, Ningbo 315211, China; (Z.Z.); (A.H.); (K.Y.)
- The Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
| | - Xiangyan Kong
- The Institute for Future Wireless Research (iFWR), Ningbo University, Ningbo 315211, China; (Z.Z.); (A.H.); (K.Y.)
- The Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
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Semeia L, Middelmann T, Baek S, Sometti D, Chen H, Grimm A, Lerche H, Martin P, Kronlage C, Braun C, Broser P, Siegel M, Breu MS, Marquetand J. Optically pumped magnetometers detect altered maximal muscle activity in neuromuscular disease. Front Neurosci 2022; 16:1010242. [DOI: 10.3389/fnins.2022.1010242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/21/2022] [Indexed: 11/30/2022] Open
Abstract
Optically pumped magnetometers (OPM) are quantum sensors that enable the contactless, non-invasive measurement of biomagnetic muscle signals, i.e., magnetomyography (MMG). Due to the contactless recording, OPM-MMG might be preferable to standard electromyography (EMG) for patients with neuromuscular diseases, particularly when repetitive recordings for diagnostic and therapeutic monitoring are mandatory. OPM-MMG studies have focused on recording physiological muscle activity in healthy individuals, whereas research on neuromuscular patients with pathological altered muscle activity is non-existent. Here, we report a proof-of-principle study on the application of OPM-MMG in patients with neuromuscular diseases. Specifically, we compare the muscular activity during maximal isometric contraction of the left rectus femoris muscle in three neuromuscular patients with severe (Transthyretin Amyloidosis in combination with Pompe’s disease), mild (Charcot-Marie-Tooth disease, type 2), and without neurogenic, but myogenic, damage (Myotonia Congenita). Seven healthy young participants served as the control group. As expected, and confirmed by using simultaneous surface electromyography (sEMG), a time-series analysis revealed a dispersed interference pattern during maximal contraction with high amplitudes. Furthermore, both patients with neurogenic damage (ATTR and CMT2) showed a reduced variability of the MMG signal, quantified as the signal standard deviation of the main component of the frequency spectrum, highlighting the reduced possibility of motor unit recruitment due to the loss of motor neurons. Our results show that recording pathologically altered voluntary muscle activity with OPM-MMG is possible, paving the way for the potential use of OPM-MMG in larger studies to explore the potential benefits in clinical neurophysiology.
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Llinás RR, Rykunov S, Walton KD, Boyko A, Ustinin M. Splitting of the magnetic encephalogram into «brain» and «non-brain» physiological signals based on the joint analysis of frequency-pattern functional tomograms and magnetic resonance images. Front Neural Circuits 2022; 16:834434. [PMID: 36092277 PMCID: PMC9458866 DOI: 10.3389/fncir.2022.834434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
The article considers the problem of dividing the encephalography data into two time series, that generated by the brain and that generated by other electrical sources located in the human head. The magnetic encephalograms and magnetic resonance images of the head were recorded in the Center for Neuromagnetism at NYU Grossman School of Medicine. Data obtained at McGill University and Montreal University were also used. Recordings were made in a magnetically shielded room and the gradiometers were designed to suppress external noise, making it possible to eliminate them from the data analysis. Magnetic encephalograms were analyzed by the method of functional tomography, based on the Fourier transform and on the solution of inverse problem for all frequencies. In this method, one spatial position is assigned to each frequency component. Magnetic resonance images of the head were evaluated to annotate the space to be included in the analysis. The included space was divided into two parts: «brain» and «non-brain». The frequency components were classified by the feature of their inclusion in one or the other part. The set of frequencies, designated as «brain», represented the partial spectrum of the brain signal, while the set of frequencies designated as «non-brain», represented the partial spectrum of the physiological noise produced by the head. Both partial spectra shared the same frequency band. From the partial spectra, a time series of the «brain» area signal and «non-brain» area head noise were reconstructed. Summary spectral power of the signal was found to be ten times greater than the noise. The proposed method makes it possible to analyze in detail both the signal and the noise components of the encephalogram and to filter the magnetic encephalogram.
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Affiliation(s)
- Rodolfo R. Llinás
- Department of Neuroscience, Center for Neuromagnetism, New York University Grossman School of Medicine, New York, NY, United States
| | - Stanislav Rykunov
- Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, Russia
- *Correspondence: Stanislav Rykunov,
| | - Kerry D. Walton
- Department of Neuroscience, Center for Neuromagnetism, New York University Grossman School of Medicine, New York, NY, United States
| | - Anna Boyko
- Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail Ustinin
- Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, Russia
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Klotz T, Gizzi L, Röhrle O. Investigating the spatial resolution of EMG and MMG based on a systemic multi-scale model. Biomech Model Mechanobiol 2022; 21:983-997. [PMID: 35441905 PMCID: PMC9132853 DOI: 10.1007/s10237-022-01572-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 03/07/2022] [Indexed: 11/25/2022]
Abstract
While electromyography (EMG) and magnetomyography (MMG) are both methods to measure the electrical activity of skeletal muscles, no systematic comparison between both signals exists. Within this work, we propose a novel in silico model for EMG and MMG and test the hypothesis that MMG surpasses EMG in terms of spatial selectivity, i.e. the ability to distinguish spatially shifted sources. The results show that MMG provides a slightly better spatial selectivity than EMG when recorded directly on the muscle surface. However, there is a remarkable difference in spatial selectivity for non-invasive surface measurements. The spatial selectivity of the MMG components aligned with the muscle fibres and normal to the body surface outperforms the spatial selectivity of surface EMG. Particularly, for the MMG’s normal-to-the-surface component the influence of subcutaneous fat is minimal. Further, for the first time, we analyse the contribution of different structural components, i.e. muscle fibres from different motor units and the extracellular space, to the measurable biomagnetic field. Notably, the simulations show that for the normal-to-the-surface MMG component, the contribution from volume currents in the extracellular space and in surrounding inactive tissues, is negligible. Further, our model predicts a surprisingly high contribution of the passive muscle fibres to the observable magnetic field.
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Affiliation(s)
- Thomas Klotz
- Institute for Modelling and Simulation of Biomechanical Systems, Pfaffenwaldring 5a, 70569 Stuttgart, Germany
- Stuttgart Centre for Simulation Science (SimTech), Pfaffenwaldring 5a, 70569 Stuttgart, Germany
| | - Leonardo Gizzi
- Institute for Modelling and Simulation of Biomechanical Systems, Pfaffenwaldring 5a, 70569 Stuttgart, Germany
- Stuttgart Centre for Simulation Science (SimTech), Pfaffenwaldring 5a, 70569 Stuttgart, Germany
| | - Oliver Röhrle
- Institute for Modelling and Simulation of Biomechanical Systems, Pfaffenwaldring 5a, 70569 Stuttgart, Germany
- Stuttgart Centre for Simulation Science (SimTech), Pfaffenwaldring 5a, 70569 Stuttgart, Germany
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Sometti D, Semeia L, Baek S, Chen H, Righetti G, Dax J, Kronlage C, Kirchgässner M, Romano A, Heilos J, Staber D, Oppold J, Middelmann T, Braun C, Broser P, Marquetand J. Muscle Fatigue Revisited – Insights From Optically Pumped Magnetometers. Front Physiol 2021; 12:724755. [PMID: 34975515 PMCID: PMC8718712 DOI: 10.3389/fphys.2021.724755] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/25/2021] [Indexed: 11/13/2022] Open
Abstract
So far, surface electromyography (sEMG) has been the method of choice to detect and evaluate muscle fatigue. However, recent advancements in non-cryogenic quantum sensors, such as optically pumped magnetometers (OPMs), enable interesting possibilities to flexibly record biomagnetic signals. Yet, a magnetomyographic investigation of muscular fatigue is still missing. Here, we simultaneously used sEMG (4 surface electrode) and OPM-based magnetomyography (OPM-MMG, 4 sensors) to detect muscle fatigue during a 3 × 1-min isometric contractions of the left rectus femoris muscle in 7 healthy participants. Both signals exhibited the characteristic spectral compression distinctive for muscle fatigue. OPM-MMG and sEMG slope values, used to quantify the spectral compression of the signals, were positively correlated, displaying similarity between the techniques. Additionally, the analysis of the different components of the magnetic field vector enabled speculations regarding the propagation of the muscle action potentials (MAPs). Altogether these results show the feasibility of the magnetomyographic approach with OPMs and propose a potential alternative to sEMG for the study of muscle fatigue.
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Affiliation(s)
- Davide Sometti
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tübingen, Tübingen, Germany
- Center for Pediatric Clinical Studies, University of Tübingen, Tübingen, Germany
| | - Lorenzo Semeia
- Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), IDM/fMEG Center of the Helmholtz Center Munich at the University of Tübingen, University of Tübingen, Tübingen, Germany
| | - Sangyeob Baek
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
| | - Hui Chen
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
| | - Giulia Righetti
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tübingen, Tübingen, Germany
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Juergen Dax
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
| | - Cornelius Kronlage
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Milena Kirchgässner
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Alyssa Romano
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Johanna Heilos
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Deborah Staber
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Julia Oppold
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Thomas Middelmann
- Department of Biosignals, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Christoph Braun
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
- Department of Psychology and Cognitive Science (DiPsCo), University of Trento, Rovereto, Italy
| | - Philip Broser
- Children’s Hospital of Eastern Switzerland, Sankt Gallen, Switzerland
| | - Justus Marquetand
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- MEG-Center, University of Tübingen, Tübingen, Germany
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- *Correspondence: Justus Marquetand,
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Marquetand J, Middelmann T, Dax J, Baek S, Sometti D, Grimm A, Lerche H, Martin P, Kronlage C, Siegel M, Braun C, Broser P. Optically pumped magnetometers reveal fasciculations non-invasively. Clin Neurophysiol 2021; 132:2681-2684. [PMID: 34274216 DOI: 10.1016/j.clinph.2021.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE This proof-of-principle-study evaluated the extent to which spontaneous activity (SA) of the muscle can be detected via non-invasive magnetomyography (MMG) with optically pumped magnetometers (OPM). METHODS Five patients, who together exhibited all forms of SA (fibrillations, positive sharp waves, fasciculations, myotonic discharges, complex-repetitive discharges) with conventional needle electromyography (EMG), were studied by OPM-MMG and simultaneous surface EMG (sEMG) while at rest, during light muscle activation, and when a muscle stretch reflex was elicited. Three healthy subjects were measured as controls. SA was considered apparent in the OPM-MMG if a signal could be visually detected that corresponded in shape and frequency to the SA in the respective needle EMG. RESULTS SA in the context of fasciculations could be detected in 2 of 5 patients by simultaneous OPM-MMG/sEMG. Other forms of SA could not be detected at rest, during light muscle activation, or after provocation of a muscle stretch reflex. CONCLUSIONS Results show that fasciculations could be detected non-invasively via a new method (OPM). SIGNIFICANCE We show that other forms of SA are not detectable with current OPM and propose necessary technical solutions to overcome this circumstance. Our results motivate to pursue OPM-MMG as a new clinical neurophysiological diagnostic.
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Affiliation(s)
- Justus Marquetand
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany.
| | - Thomas Middelmann
- Department of Biosignals, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Juergen Dax
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany
| | - Sangyeob Baek
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany
| | - Davide Sometti
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany
| | - Alexander Grimm
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Holger Lerche
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Pascal Martin
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Cornelius Kronlage
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Markus Siegel
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany; Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Christoph Braun
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; MEG-Center, University of Tübingen, Tübingen, Germany; CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy; DiPsCo, Department of Psychology and Cognitive Science, University of Trento, Rovereto, Italy
| | - Philip Broser
- Children's Hospital of Eastern Switzerland, Sankt Gallen, Switzerland
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