553 results match your criteria Single-Fiber EMG


Repetitive ocular vestibular evoked myogenic potentials in myasthenia gravis.

Neurology 2020 Apr 26;94(16):e1693-e1701. Epub 2020 Mar 26.

From the Department of Neurology (R.H.P.d.M., K.R.K., U.A.B, J.J.V., M.R.T.), Leiden University Medical Center, the Netherlands; and Departments of Ophthalmology (M.A.W., K.P.W.) and Neurology (K.P.W.), University Hospital Zurich, University of Zurich, Switzerland.

Objective: To validate the repetitive ocular vestibular evoked myogenic potentials (RoVEMP) test for diagnostic use in myasthenia gravis (MG) and to investigate its value in diagnostically challenging subgroups.

Methods: The RoVEMP test was performed in 92 patients with MG, 22 healthy controls, 33 patients with a neuromuscular disease other than MG (neuromuscular controls), 4 patients with Lambert-Eaton myasthenic syndrome, and 2 patients with congenital myasthenic syndrome.

Results: Mean decrement was significantly higher in patients with MG (28. Read More

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http://dx.doi.org/10.1212/WNL.0000000000009306DOI Listing

Clinical duration of action of different botulinum toxin types in humans.

Toxicon 2020 May 14;179:84-91. Epub 2020 Mar 14.

Neurological Unit 1, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, 20133, Milan, Italy. Electronic address:

The Botulinum NeuroToxin (BoNT) comprises several serotypes with distinct properties, mechanisms of action, sensitivity and duration of effect in different species. The serotype A (BoNT/A) is the prevalent neurotoxin applied in human's disease. In this paper we present an overview of the current knowledge regarding the duration of effect and the neuromuscular sprouting of different BoNT serotypes in humans. Read More

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http://dx.doi.org/10.1016/j.toxicon.2020.02.020DOI Listing

Botulinum toxin injections associated with suspected myasthenia gravis: An underappreciated cause of MG-like clinical presentation.

Clin Neurophysiol Pract 2020 7;5:46-49. Epub 2020 Feb 7.

Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden.

Introduction: The application of botulinum toxin type A (BoNTA) is accelerating, and this includes the uncontrolled cosmetic use of the BoNTA. Diffusion of BoNTA can disturb neuromuscular transmission in several surrounding and distant muscles and result in clinical manifestations similar to myasthenia gravis (MG).

Case Presentations: We report two cases of patients referred for neurophysiological evaluation of suspected MG. Read More

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http://dx.doi.org/10.1016/j.cnp.2020.01.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7044641PMC
February 2020

Objectivation of laryngeal electromyography (LEMG) data: turn number vs. qualitative analysis.

Eur Arch Otorhinolaryngol 2020 May 18;277(5):1409-1415. Epub 2020 Feb 18.

Division of Phoniatrics-Logopedics, Department of Otorhinolaryngology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.

Purpose: This paper describes a first attempt to quantify LEMG data based on turn number calculation. The results obtained for both healthy and ailing thyroarytenoid (TA) muscles of patients with unilateral vocal fold immobility (UVFI) were compared with the respective qualitative evaluation concerning volitional activity to determine whether the two types of analyses deliver similar results.

Methods: LEMG data obtained from 44 adults with UVFI were considered for the study. Read More

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http://dx.doi.org/10.1007/s00405-020-05846-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160217PMC

[Electrophysiological evidence of impaired neuromuscular junction in a case of phosphoglucomutase 1 deficiency manifesting fluctuating muscle weakness].

Rinsho Shinkeigaku 2020 Feb 19;60(2):152-156. Epub 2020 Jan 19.

Division of Neurology, Kobe University Graduate School of Medicine.

A 27 year-old Canadian man suffered from fluctuating muscle weakness in the past several years. The patient had a past history of intestinal bleeding, bifid uvula and hypothyroidism in his childhood. Repetitive nerve stimulation tests showed a decrement pattern in the left deltoid muscle. Read More

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http://dx.doi.org/10.5692/clinicalneurol.cn-001375DOI Listing
February 2020

Neuromuscular junction transmission failure is a late phenotype in aging mice.

Neurobiol Aging 2020 02 5;86:182-190. Epub 2019 Nov 5.

Department of Neurology, Neuromuscular Division, The Ohio State University, Wexner Medical Center, Columbus, OH, USA; Department of Physical Medicine and Rehabilitation, The Ohio State University, Wexner Medical Center, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University, Wexner Medical Center, Columbus, OH, USA. Electronic address:

Neurodegeneration has increasingly been considered an important factor in the pathogenesis of sarcopenia or age-related loss of muscle mass and strength. Experiments were designed to investigate the fidelity of neuromuscular junction (NMJ) transmission across the lifespan in hindlimb muscles of male and female C57BL/6J mice (at 12, 20, 24, 27, and 29 months of age). Single-fiber electromyography recordings demonstrated abrupt onset of NMJ transmission failure at 27 months of age. Read More

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http://dx.doi.org/10.1016/j.neurobiolaging.2019.10.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6995686PMC
February 2020

Cosmetic Injection of Botulinum Toxin Unmasking Subclinical Myasthenia Gravis: A Case Report and Literature Review.

Case Rep Neurol 2019 May-Aug;11(2):244-251. Epub 2019 Aug 16.

Department of Neurology, University of Liège, CHU Sart-Tilman, Liège, Belgium.

Cosmetic or therapeutic use of botulinum toxin type A (BoNT-A) is usually safe but can rarely cause iatrogenic botulism. Iatrogenic botulism and myasthenia gravis (MG) share similar clinical features, because both BoNT-A and anti-acetylcholine receptorantibodies impair neuromuscular transmission. We report a patient who underwent cosmetic BoNT-A injection and later developed serious local and systemic adverse reactions. Read More

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http://dx.doi.org/10.1159/000502350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751432PMC
August 2019
5 Reads

Baseline Decrement in Patients with Mild Myasthenia Gravis Predicts Immunomodulation Treatment.

Can J Neurol Sci 2019 11;46(6):762-766

Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.

To explore whether higher degrees of electrophysiological abnormalities are associated with a more frequent exposure to a more aggressive treatment regimen, we performed a retrospective chart review of patients attending the neuromuscular clinic from June 2012 to December 2015 and included 87 patients. We compared treatment regimens during the follow-up period between patients with high and low jitter and decrement. Myasthenia gravis patients with high jitter or decrement at baseline were more frequently treated with intravenous immunoglobulins (IVIG) and/or plasma exchange (PLEX) during the follow-up period. Read More

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http://dx.doi.org/10.1017/cjn.2019.246DOI Listing
November 2019
3 Reads

Inter-rater reliability of seven neurolaryngologists in laryngeal EMG signal interpretation.

Eur Arch Otorhinolaryngol 2019 Oct 16;276(10):2849-2856. Epub 2019 Jul 16.

Division of Phoniatrics-Logopedics, Department of Otorhinolaryngology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.

Purpose: Laryngeal electromyography (LEMG) has been considered as gold standard in diagnostics of vocal fold movement impairment, but is still not commonly implemented in clinical routine. Since the signal interpretation of LEMG signals (LEMGs) is often a subjective and semi-quantitative matter, the goal of this study was to evaluate the inter-rater reliability of neurolaryngologists on LEMGs of volitional muscle activity.

Methods: For this study, 52 representative LEMGs of 371 LEMG datasets were selected from a multicenter registry for a blinded evaluation by 7 experienced members of the neurolaryngology working group of the European Laryngological Society (ELS). Read More

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http://dx.doi.org/10.1007/s00405-019-05553-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757022PMC
October 2019
3 Reads

Clinical neurophysiology of neuromuscular junction disease.

Authors:
Vern C Juel

Handb Clin Neurol 2019 ;161:291-303

Department of Neurology, Duke University School of Medicine, Durham, NC, United States. Electronic address:

The neuromuscular junction (NMJ) is a cholinergic synapse where quantal release of acetylcholine (ACh) from motor nerve terminals generates a local endplate potential (EPP) on the muscle fiber. EPPs that reach threshold depolarize the entire muscle fiber and initiate the process of excitation-contraction coupling. Deficits of neuromuscular transmission result in clinical weakness that is fatigable and may fluctuate. Read More

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http://dx.doi.org/10.1016/B978-0-444-64142-7.00055-2DOI Listing
January 2020
5 Reads

Single-fiber electromyography-based diagnosis of CACNA1A mutation in children: A potential role of the electrodiagnosis in the era of whole exome sequencing.

Brain Dev 2019 Nov 6;41(10):905-909. Epub 2019 Jul 6.

Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Japan.

Introduction: A loss-of-function mutation in CACNA1A, which encodes P/Q-type Ca channels, causes various diseases. As most of the Ca channels at neuromuscular junctions are of the P/Q type, patients with loss-of-function CACNA1A mutations exhibit disturbed neuromuscular transmission. The associated jitters and blocking in such patients can be detected by single-fiber electromyography (SFEMG). Read More

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http://dx.doi.org/10.1016/j.braindev.2019.06.006DOI Listing
November 2019
8 Reads

Single fiber electromyography.

Authors:
Vern C Juel

Handb Clin Neurol 2019 ;160:303-310

Department of Neurology, Duke University School of Medicine, Durham, NC, United States. Electronic address:

Single fiber electromyography (SFEMG) is a highly selective technique that permits assessment of individual muscle fiber action potentials (MFAPs). This selectivity is achieved with a specialized concentric needle electrode with a 25-μm diameter recording surface located in a side port 3mm from the needle tip. Additional selectivity is achieved with 500-Hz low-frequency filtering. Read More

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http://dx.doi.org/10.1016/B978-0-444-64032-1.00019-9DOI Listing
December 2019
3 Reads

Standards for quantification of EMG and neurography.

Clin Neurophysiol 2019 09 10;130(9):1688-1729. Epub 2019 Jun 10.

Department of Neurology, Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, Heeze, the Netherlands.

This document is an update and extension of ICCN Standards published in 1999. It is the consensus of experts on the current status of EMG and Neurography methods. A panel of authors from different countries with different approach to routines in neurophysiological methods was chosen based on their particular interest and previous publications. Read More

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http://dx.doi.org/10.1016/j.clinph.2019.05.008DOI Listing
September 2019
18 Reads

Single fiber EMG guidelines: Moving towards a "single" methodological consensus.

Clin Neurophysiol 2019 08 8;130(8):1399-1400. Epub 2019 May 8.

Department of Neurology and Psychiatry, Clínica Alemana de Santiago-Universidad del Desarrollo, Santiago, Chile. Electronic address:

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http://dx.doi.org/10.1016/j.clinph.2019.04.610DOI Listing
August 2019
10 Reads

Guidelines for single fiber EMG.

Clin Neurophysiol 2019 08 27;130(8):1417-1439. Epub 2019 Apr 27.

Department of Clinical Neurophysiology, Uppsala University, Uppsala, Sweden. Electronic address:

This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG) and the measurement of neuromuscular jitter with concentric needle electrodes (CNE - CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S13882457193012
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http://dx.doi.org/10.1016/j.clinph.2019.04.005DOI Listing
August 2019
10 Reads

Incidence, Epidemiology, and Transformation of Ocular Myasthenia Gravis: A Population-Based Study.

Am J Ophthalmol 2019 09 9;205:99-105. Epub 2019 May 9.

Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA; Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA. Electronic address:

Purpose: To establish the incidence of ocular myasthenia gravis (OMG) as well as identify determinants of transformation to generalized myasthenia gravis (GMG) using a population-based record-linkage system.

Design: Population-based, retrospective cohort study.

Methods: All adults (≥18 years) diagnosed with myasthenia gravis (MG) from January 1, 1990, through December 31, 2017, were identified using the Rochester Epidemiology Project. Read More

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http://dx.doi.org/10.1016/j.ajo.2019.04.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6744973PMC
September 2019
5 Reads

Evolution of single fiber potential (SFP) criteria towards improving jitter measurement.

Neurophysiol Clin 2019 06 23;49(3):205-207. Epub 2019 Apr 23.

Department of Neurology, Medical University of Warsaw, Banacha 1A str., 02-097 Warsaw, Poland. Electronic address:

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http://dx.doi.org/10.1016/j.neucli.2019.04.001DOI Listing
June 2019
1 Read

Myasthenia graves-like symptoms associated with rare mitochondrial mutation (m.5728T>C).

Mitochondrion 2019 07 23;47:139-140. Epub 2019 Apr 23.

Depertment of Pediatric Laboratory Medicine, Divison of Clinical Biochemistry, The Hospital for Sick Children, Toronto, Ontario, M5G2L3, Canada.

We report here on a patient who presented with myasthenia gravis type symptoms (fatigable ptosis, increased jitter on single fiber EMG, and a thymic mass) who was subsequently diagnosed with a mitochondrial myopathy. Sequencing of the mitochondrial genome (mtDNA) identified a transition variant in the tRNA asparagine gene (MT-TN) (m.5728T>C) at in 41% of mtDNA molecules in muscle tissue. Read More

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http://dx.doi.org/10.1016/j.mito.2019.04.003DOI Listing
July 2019
21 Reads

Toxic doses of caffeine are needed to increase skeletal muscle contractility.

Am J Physiol Cell Physiol 2019 02 19;316(2):C246-C251. Epub 2018 Dec 19.

Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland.

Discrepant results have been reported regarding an intramuscular mechanism underlying the ergogenic effect of caffeine on neuromuscular function in humans. Here, we reevaluated the effect of caffeine on muscular force production in humans and combined this with measurements of the caffeine dose-response relationship on force and cytosolic free [Ca] ([Ca]) in isolated mouse muscle fibers. Twenty-one healthy and physically active men (29 ± 9 yr, 178 ± 6 cm, 73 ± 10 kg, mean ± SD) took part in the present study. Read More

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http://dx.doi.org/10.1152/ajpcell.00269.2018DOI Listing
February 2019
2 Reads

Motor Unit Properties of the First Dorsal Interosseous in Chronic Stroke Subjects: Concentric Needle and Single Fiber EMG Analysis.

Front Physiol 2018 3;9:1587. Epub 2018 Dec 3.

Department of Physical Medicine & Rehabilitation, The University of Texas Health Science Center at Houston, Houston, TX, United States.

The purpose of this study was to better understand changes in motor unit electrophysiological properties in people with chronic stroke based on concentric needle electromyography (EMG) and single fiber EMG recordings. The first dorsal interosseous (FDI) muscle was studied bilaterally in eleven hemiparetic stroke subjects. A significant increase in mean fiber density (FD) was found in the paretic muscle compared with the contralateral side based on single fiber EMG (1. Read More

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http://dx.doi.org/10.3389/fphys.2018.01587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6287192PMC
December 2018
7 Reads

Concentric or monopolar electrode for jitter determination in orbicularis oculi.

Clin Neurophysiol 2018 12 26;129(12):2552-2556. Epub 2018 Oct 26.

Institute of Physiology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Portugal; Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Portugal. Electronic address:

Objectives: To investigate if monopolar (MN) and concentric (CN) electrodes are equivalent for volitional contraction jitter estimation in orbicularis oculi (OO), and to study the effect of selecting a specific high-pass filter.

Methods: We studied neuromuscular jitter in OO on both sides in 100 consecutive patients with a clinical diagnosis of ocular myasthenia gravis (MG). We used either MN (50 patients) or CN (50 patients) electrodes in individual patients, according to a randomised protocol, with a 1kH high pass filter on one side and a 3kH filter on the other. Read More

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http://dx.doi.org/10.1016/j.clinph.2018.09.024DOI Listing
December 2018
41 Reads

Glioneuronal brainstem tumor - It's all in the eyes.

J Clin Neurosci 2019 Feb 23;60:151-153. Epub 2018 Oct 23.

Alfred Hospital, Department of Neurology, Melbourne, Australia. Electronic address:

A previously well man presented with several months' history of neurological symptoms including diplopia and balance difficulties. Examination revealed fluctuating neurological deficits, fatigable weakness and slowed saccades. Extensive testing revealed mildly elevated cerebrospinal fluid protein, strongly positive single fiber electromyography and a dorsal pontine lesion at the floor of the 4th ventricle. Read More

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http://dx.doi.org/10.1016/j.jocn.2018.10.084DOI Listing
February 2019
41 Reads

Identification of components from distant fibers in a recorded single muscle fiber potential (SFP) - a new approach to the SFP criteria.

Neurophysiol Clin 2019 Feb 14;49(1):69-80. Epub 2018 Oct 14.

Department of Neurology, Medical University of Warsaw, Banacha 1A str., 02-097 Warsaw, Poland. Electronic address:

Objectives: The aim of our study was to verify the effectiveness of single fiber potential (SFP) criteria in cases when the potential recorded using single fiber electrode (SFE) or concentric needle electrode (CNE) is contaminated by distant fibers.

Methods: Morphological counterparts of SFP were studied using computer simulations. In this study, we examined triphasic potentials using a model of a linear source of SFP. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S09877053183005
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http://dx.doi.org/10.1016/j.neucli.2018.09.003DOI Listing
February 2019
12 Reads

Stimulated single-fiber electromyography (sSFEMG) in Lambert-Eaton syndrome.

Clin Neurophysiol Pract 2018 13;3:148-150. Epub 2018 Aug 13.

I Division of Neurology and Neurophysiopathology, University of Campania "Luigi Vanvitelli", Naples, Italy.

Objective: To report the clinical features and the neurophysiological approach of a patient with Lambert-Eaton myasthenic syndrome (LEMS), highlighting the diagnostic role of the stimulated single fiber electromyography (sSFEMG).

Case Report: A 60-year-old woman presenting with the LEMS triad (proximal and axial weakness, autonomic dysfunction and areflexia) was evaluated by neurophysiological tests (electroneuromyography, repetitive stimulation test (TSR), voluntary and stimulated SFEMG). We reported: ) increase of compound muscle action potential (CMAP) amplitude (>60%) following brief isometric exercise compared to the rest (baseline); ) decremental/incremental response of CMAP amplitude at low- (3 Hz) and high-frequency (30 Hz) repetitive stimulation test (RST), respectively; ) increased neuromuscular jitter and blocking at voluntary single-fiber electromyography (vSFEMG); ) stimulation rate-dependent reduction of the neuromuscular jitter and blocking at sSFEMG. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S2467981X183002
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http://dx.doi.org/10.1016/j.cnp.2018.07.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6134173PMC
August 2018
44 Reads

Serial Stimulated Jitter Analysis In Juvenile Myasthenia Gravis.

Muscle Nerve 2018 11 2;58(5):729-732. Epub 2018 Oct 2.

Division of Pediatric Neurology, Department of Pediatrics, Emory University School of Medicine, Atlanta, 1605 Chantilly Drive NE, Suite 300, Atlanta, Georgia, 30324, USA.

Introduction: Clinical and electrophysiological studies to measures disease activity in juvenile myasthenia gravis (JMG) are limited.

Methods: Retrospective review of the clinical profile, Myasthenia Gravis Foundation of America (MGFA) scores, serial stimulated jitter analysis (Stim-JA) of the orbicularis oculi muscle, grip strength, and spirometry of patients with JMG who were followed in a multidisciplinary clinic was performed.

Results: Thirteen patients with JMG (9 females) with mean age of 13. Read More

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http://doi.wiley.com/10.1002/mus.26319
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http://dx.doi.org/10.1002/mus.26319DOI Listing
November 2018
64 Reads

Electromyography in Pediatric Population.

Noro Psikiyatr Ars 2018 Mar 19;55(1):36-39. Epub 2018 Mar 19.

Department of Neurology, Istanbul University Faculty of Medicine, İstanbul, Turkey.

Introduction: Electrodiagnostic evaluation provides an important extension to the neurological examination for the evaluation of pediatric neuromuscular disease. Many pediatric neuromuscular diseases are analogous to those seen in the adult. However, the relative frequency of these illnesses varies greatly when different age populations are compared. Read More

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http://dx.doi.org/10.5152/npa.17023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6045805PMC
March 2018
52 Reads

Single-fiber F waves compared with conventional surface F waves, and their utility in detecting early diabetic neuropathy.

Muscle Nerve 2018 11 19;58(5):665-670. Epub 2018 Sep 19.

Department of Neurology & Neurological Research, St. Vincent's Hospital Melbourne, P.O. Box 2900, Fitzroy, 3065, Melbourne, Australia.

Introduction: The single-fiber F-wave (SFF-wave) technique assesses the entire length of single motor fibers using a concentric needle. Herein we investigated the utility of this approach in the detection of early diabetes-related neuropathy, and compared it with the use of conventional surface F waves (CF waves).

Methods: Sixteen patients with diabetes and either no neuropathy or mild neuropathy were assessed and compared with 16 age- and height-matched control participants. Read More

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http://doi.wiley.com/10.1002/mus.26290
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http://dx.doi.org/10.1002/mus.26290DOI Listing
November 2018
38 Reads

Role of concentric needle Single Fiber Electromyography in detection of subclinical motor involvement in carpal tunnel syndrome.

Egypt J Neurol Psychiatr Neurosurg 2018 25;54(1). Epub 2018 Apr 25.

1Clinical Neurophysiology Unit, Kasr Alainy Hospital, Faculty of Medicine, Cairo University, Cairo, Egypt.

Background: Conventional motor nerve conduction studies are usually normal in early and mild carpal tunnel syndrome (CTS). Single-fiber electromyography (SFEMG) measures the mean consecutive difference (MCD) as an expression of the variability in impulse transmission over the motor endplates and along the nerve fibers distally to the last branching point and along the muscle fibers.Application of concentric needle SFEMG in a group of CTS patients who showed pure sensory abnormalities in nerve conduction studies to examine for subclinical motor involvement. Read More

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http://dx.doi.org/10.1186/s41983-018-0004-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5954771PMC
April 2018
4 Reads

Diagnosis of Myasthenia Gravis.

Neurol Clin 2018 05;36(2):261-274

Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA.

Myasthenia gravis (MG) diagnosis is primarily clinically based. By the end of the clinical evaluation, clinicians have a sense as to whether presenting symptoms and elicited signs are weakly or strongly supportive of MG. Diagnostic tests can reaffirm the clinicians' impression. Read More

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http://dx.doi.org/10.1016/j.ncl.2018.01.010DOI Listing
May 2018
44 Reads

Needle electromyography practice patterns in patients taking novel oral anticoagulants: A survey-based study.

Muscle Nerve 2018 Aug 25;58(2):307-309. Epub 2018 Mar 25.

Department of Neurology and Rehabilitation Medicine, University of Cincinnati, 260 Stetson Street Suite 2300, ML 0525, Cincinnati, Ohio, USA.

Introduction: This study sought to evaluate needle electromyography (EMG) practice patterns among electromyographers with patients taking novel oral anticoagulants (NOAC).

Methods: A survey questionnaire was sent to members of the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) via email web link. Anonymous survey responses were collected through an online website. Read More

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http://dx.doi.org/10.1002/mus.26119DOI Listing
August 2018
29 Reads

Increased Single-Fiber Jitter Level Is Associated With Reduction in Motor Function With Aging.

Am J Phys Med Rehabil 2018 08;97(8):551-556

From the Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, Maryland (TC, YT); Department of Medicine, Division of Geriatric Medicine and Gerontology, Johns Hopkins School of Medicine, Baltimore, Maryland (JW); and Department of Neurology, Neuromuscular Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland (TC, AH).

Objective: Age-associated skeletal muscle weakness is a major contributing factor to an increased late life mortality and morbidity, but its neurobiology is poorly understood. Previously, we provided histological evidence of dying-back axonal degeneration of motor neurons and denervation of neuromuscular junctions in age-associated muscle weakness. Given this, we aimed to evaluate the relation between impaired neuromuscular transmission and various aspects of age-associated muscle weakness. Read More

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http://dx.doi.org/10.1097/PHM.0000000000000915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6051904PMC
August 2018
9 Reads

Repetitive nerve stimulation and jitter measurement with disposable concentric needle electrode in newly diagnosed myasthenia gravis patients.

Neurophysiol Clin 2018 Oct 25;48(5):261-267. Epub 2018 Feb 25.

Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey.

Introduction: The aim of this study was to define the diagnostic accuracy of concentric needle (CN)-jitter in newly diagnosed myasthenia gravis (MG) patients and to compare CN-jitter with repetitive nerve stimulation.

Methods: In 30 MG patients, repetitive nerve stimulation in 4 muscles (orbicularis oculi, nasalis, trapezius and abductor digiti minimi) and CN-jitter of extensor digitorum (ED) and frontalis muscles were evaluated.

Results: Twenty-eight of 30 patients (93%) had high jitter in at least one muscle. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S09877053173027
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http://dx.doi.org/10.1016/j.neucli.2018.01.003DOI Listing
October 2018
30 Reads

Presynaptic congenital myasthenic syndrome with altered synaptic vesicle homeostasis linked to compound heterozygous sequence variants in RPH3A.

Mol Genet Genomic Med 2018 05 14;6(3):434-440. Epub 2018 Feb 14.

Department of Anesthesiology and Pain Medicine, University of California Davis, Sacramento, CA, USA.

Background: Monogenic defects of synaptic vesicle (SV) homeostasis have been implicated in many neurologic diseases, including autism, epilepsy, and movement disorders. In addition, abnormal vesicle exocytosis has been associated with several endocrine dysfunctions.

Methods: We report an 11 year old girl with learning disabilities, tremors, ataxia, transient hyperglycemia, and muscle fatigability responsive to albuterol sulfate. Read More

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http://dx.doi.org/10.1002/mgg3.370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6014458PMC
May 2018
28 Reads

Coexisting myasthenia gravis, myositis, and polyneuropathy induced by ipilimumab and nivolumab in a patient with non-small-cell lung cancer: A case report and literature review.

Medicine (Baltimore) 2017 Dec;96(50):e9262

Department of Neurology.

Rationale: Immune checkpoint inhibitors have led to the development of new approaches for cancer treatment with positive outcomes. However, checkpoint blockade is associated with a unique spectrum of immune-related adverse events (irAEs), which may cause irreversible neurological deficits and even death.

Patient Concerns: We presented a case of a 57-year-old man with non-small-cell lung cancer. Read More

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http://dx.doi.org/10.1097/MD.0000000000009262DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5815782PMC
December 2017
31 Reads

Clinical and CN-SFEMG evaluation of neostigmine test in myasthenia gravis.

Neurol Sci 2018 Feb 12;39(2):341-345. Epub 2018 Jan 12.

Department "G. F. Ingrassia", Section of Neurosciences, University of Catania, Via Santa Sofia 78, 95123, Catania, Italy.

Neostigmine test (NT) is a pharmacological test, demonstrating a clinical improvement in patients affected by myasthenia gravis (MG). We aim to compare clinical evaluation and neurophysiological recordings by concentric-needle single-fiber electromyography (CN-SFEMG) in response to acute administration of neostigmine in ocular and generalized MG patients. Twenty-three MG patients (10 with ocular MG and 13 with generalized MG) were evaluated before and after 90 min neostigmine 0. Read More

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http://link.springer.com/10.1007/s10072-017-3194-0
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http://dx.doi.org/10.1007/s10072-017-3194-0DOI Listing
February 2018
33 Reads

Extending knowledge of the clinical picture of Balkan adder (Vipera berus bosniensis) envenoming: The first photographically-documented neurotoxic case from South-Western Hungary.

Toxicon 2018 Mar 2;143:29-35. Epub 2018 Jan 2.

"Moritz Kaposi" General Hospital, Department of Surgery, Tallián Gyula u. 20-32, H-7400 Kaposvár, Hungary.

We report a severe envenoming associated with minimal local symptoms following a Balkan adder (Vipera berus bosniensis) bite in South-Western Hungary. A 63-year-old male with a history of hypertension and sinus bradycardia (45/min) was bitten by a sub-adult specimen of V. b. Read More

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http://dx.doi.org/10.1016/j.toxicon.2017.12.053DOI Listing
March 2018
28 Reads

Correlating motor unit morphology with bioelectrical activity - A simulation study.

Clin Neurophysiol 2018 01 16;129(1):271-279. Epub 2017 Nov 16.

Neuromuscular Unit, Mossakowski Medical Research Center, Polish Academy of Sciences, 02-106 Warsaw, Pawinskiego 5, Poland.

Objectives: The aim was to determine motor unit morphology underpinning the various MUP waveforms using MUP analysis.

Method: The simulation method is based on the decomposition of MUP into single fiber potentials. Number of fibers, fiber diameters and fiber to electrode distances were determined. Read More

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http://dx.doi.org/10.1016/j.clinph.2017.11.003DOI Listing
January 2018
14 Reads

Confirmed Ceylon krait (Bungarus ceylonicus) envenoming in Sri Lanka resulting in neuromuscular paralysis: a case report.

J Med Case Rep 2017 Nov 24;11(1):330. Epub 2017 Nov 24.

Department of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.

Background: Ceylon krait (Bungarus ceylonicus) is a venomous elapid snake endemic to Sri Lanka. It inhabits shaded home gardens and forests in the wet zone of Sri Lanka and might creep into houses in the night. Despite frequent encounters with humans, reports of envenoming are very rare. Read More

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https://jmedicalcasereports.biomedcentral.com/articles/10.11
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http://dx.doi.org/10.1186/s13256-017-1503-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701456PMC
November 2017
31 Reads

Deriving muscle fiber diameter from recorded single fiber potential.

Authors:
Ewa Zalewska

Neurophysiol Clin 2017 Dec 20;47(5-6):413-417. Epub 2017 Nov 20.

Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 str., 02-109 Warsaw, Poland. Electronic address:

Objective: The aim of the study was to estimate muscle fiber diameters through analysis of single muscle fiber potentials (SFPs) recorded in the frontalis muscle of a healthy subject.

Methods: Our previously developed analytical and graphic method to derive fiber diameter from the analysis of the negative peak duration and the amplitude of SFP, was applied to a sample of ten SFPs recorded in vivo.

Results: Muscle fiber diameters derived from the simulation method for the sample of frontalis muscle SFPs are consistent with anatomical data for this muscle. Read More

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http://dx.doi.org/10.1016/j.neucli.2017.10.058DOI Listing
December 2017
7 Reads

Mechanism hypotheses for the electrophysiological manifestations of two cases of endplate acetylcholinesterase deficiency related congenital myasthenic syndrome.

J Clin Neurosci 2018 Feb 14;48:229-232. Epub 2017 Nov 14.

Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China; Neuroscience Center, Chinese Academy of Medical Sciences, Beijing 100730, China. Electronic address:

Objective: To summarize the electrophysiological characteristics of two cases of endplate acetylcholinesterase deficiency (EAD) related congenital myasthenic syndrome (CMS) caused by COLQ mutation and to discuss the possible mechanism of these electrophysiological phenomena.

Methods: Electrophysiological examinations were conducted including nerve conduction studies, routine electromyography (EMG), repetitive nerve stimulation (RNS) and single fiber EMG (SFEMG). The ulnar nerve was also stimulated at 50 Hz followed by 0. Read More

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http://dx.doi.org/10.1016/j.jocn.2017.10.084DOI Listing
February 2018
20 Reads

Congenital Myasthenic Syndrome due to mutations in a family from Chile.

Eur J Transl Myol 2017 06 20;27(3):6832. Epub 2017 Sep 20.

Department of Neurology, University of California Davis, Davis CA, USA

Congenital myasthenic syndromes (CMS) are neuromuscular transmission disorders caused by mutations in genes encoding neuromuscular junction proteins. A 61-year-old female and her older sister showed bilateral ptosis, facial and proximal limb weakness, and scoliosis since childhood. Another female sibling had milder signs, while other family members were asymptomatic. Read More

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http://www.pagepressjournals.org/index.php/bam/article/view/
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http://dx.doi.org/10.4081/ejtm.2017.6832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5658635PMC
June 2017
26 Reads

Pitfalls and errors in measuring jitter.

Clin Neurophysiol 2017 11 21;128(11):2233-2241. Epub 2017 Sep 21.

Faculdade Medicina Sao Jose do Rio Preto, Investigation Neuromuscular Laboratory, 15090-000 Sao Jose do Rio Preto, SP, Brazil. Electronic address:

The safety factor of neuromuscular transmission can be assessed by measuring the neuromuscular jitter, which reflects the time variability of processes in the motor end-plate. Jitter is increased in any condition with disturbed end-plate function, such as myasthenic conditions and ongoing reinnervation. Jitter is increasingly being measured with concentric needle (CN) electrodes, which are more prone to artefacts than single fiber EMG recordings. Read More

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http://dx.doi.org/10.1016/j.clinph.2017.09.001DOI Listing
November 2017
17 Reads

Single-fiber electromyography in the orbicularis oculi muscle in patients with ocular myasthenia gravis symptoms: does abnormal jitter predict response to treatment?

BMC Neurol 2017 Jun 7;17(1):108. Epub 2017 Jun 7.

EMG Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.

Background: Seronegative ocular myasthenia gravis (OMG) is diagnosed by ocular symptoms with supporting SFEMG, typically of frontalis or extensor digitorum muscles. We aimed to determine the sensitivity and specificity of orbicularis oculi SFEMG to diagnose and exclude myasthenia gravis and predict response to therapy.

Methods: Orbicularis oculi SFEMG studies were conducted in 142 consecutive patients with symptoms and/or findings of OMG and negative AChR antibody during the period of 5 years. Read More

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http://dx.doi.org/10.1186/s12883-017-0891-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5463377PMC
June 2017
57 Reads

Selective or predominant triceps muscle weakness in African-American patients with myasthenia gravis.

Neuromuscul Disord 2017 Jul 21;27(7):646-649. Epub 2017 Apr 21.

Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada.

Myasthenia gravis (MG) can lead to weakness in different patterns of muscle groups. Limb muscle weakness is most typically seen in a limb girdle pattern, although variants exist. In the current study, we aimed to describe a unique MG phenotype consisting of selective or predominant triceps muscle weakness. Read More

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http://dx.doi.org/10.1016/j.nmd.2017.04.009DOI Listing
July 2017
25 Reads

Use of stimulated electromyography in the analysis of the neuromuscular junction in children.

Authors:
Matthew C Pitt

Muscle Nerve 2017 Nov 22;56(5):841-847. Epub 2017 May 22.

Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, United Kingdom.

A screening test is required to diagnose disorders of the neuromuscular junction (NMJ) in children. This Review describes the development of stimulation potential analysis with concentric needle electrodes (SPACE). This nomenclature was chosen to distinguish the technique from single-fiber methodology because of the difficulties in identifying single-fiber potentials in most studies, particularly those with the most severe abnormalities of the NMJ. Read More

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http://dx.doi.org/10.1002/mus.25685DOI Listing
November 2017
11 Reads

A reappraisal of diagnostic tests for myasthenia gravis in a large Asian cohort.

J Neurol Sci 2017 May 14;376:153-158. Epub 2017 Mar 14.

Duke-NUS Graduate Medical School, Singapore; Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore.

Background: Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease characterized by weakness of bodily skeletal muscles. Office-based diagnostic tests such as repetitive nerve stimulation (RNS), single fiber electromyography (SFEMG), and the ice test, are used to refine the differential clinical diagnosis of this disease. Evaluating the clinical sensitivity and specificity of these tests, however, may be confounded by lack of a gold standard, non-blinding, incorporation bias, use of non-representative populations and retrospective data. Read More

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http://dx.doi.org/10.1016/j.jns.2017.03.016DOI Listing
May 2017
33 Reads

Hinge-deleted IgG4 blocker therapy for acetylcholine receptor myasthenia gravis in rhesus monkeys.

Sci Rep 2017 04 20;7(1):992. Epub 2017 Apr 20.

Genmab, Utrecht, The Netherlands.

Autoantibodies against ion channels are the cause of numerous neurologic autoimmune disorders. Frequently, such pathogenic autoantibodies have a restricted epitope-specificity. In such cases, competing antibody formats devoid of pathogenic effector functions (blocker antibodies) have the potential to treat disease by displacing autoantibodies from their target. Read More

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http://dx.doi.org/10.1038/s41598-017-01019-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5430546PMC
April 2017
25 Reads

Jitter Values on Voluntary Active Periocular Muscles of Healthy Subjects with Conventional (37 mm) Concentric Needle Electrode.

Noro Psikiyatr Ars 2016 Jun 1;53(2):126-129. Epub 2016 Jun 1.

Department of Neurology and Clinical Neurophysiology, İstanbul University İstanbul School of Medicine, İstanbul, Turkey.

Introduction: The aim of this study was to re-evaluate jitter values of healthy subjects in whom pairs of single-fiber-like potentials were recorded from voluntary activated periocular muscles using a disposable 37-mm concentric needle electrode (CNE) with 2-kHz low-cut filtering.

Methods: We reviewed the recordings of 129 subjects (85 women; 44 men; mean age, 43.8±15. Read More

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http://dx.doi.org/10.5152/npa.2015.12390DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353016PMC
June 2016
42 Reads

Low-Density Lipoprotein Receptor-Related Protein 4-Positive Myasthenia Gravis in a Double-Seronegative, Electromyography-Negative Patient.

J Neuroophthalmol 2017 09;37(3):285-286

Department of Ophthalmology (JMK), Hadassah Medical Center, Kiryat Hadassah, Jerusalem, Israel; Neuroimmunology and Cell Therapy Unit (DK, PP), Neurology Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; and Department of Neurobiology (PZ), Hellenic Pasteur Institute, Greece and Tzartos NeuroDiagnostics, Athens, Greece.

We describe a patient with ocular myasthenia gravis, where single-fiber electromyography and testing for acetylcholine receptor and muscle-specific kinase antibodies were negative. However, antibodies to low-density lipoprotein receptor-related protein 4 (LRP4) were positive, and this prompted appropriate management. We recommend that testing for LRP4 antibodies be considered when the clinical suspicion for myasthenia gravis is high despite negative conventional diagnostic tests. Read More

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http://dx.doi.org/10.1097/WNO.0000000000000499DOI Listing
September 2017
19 Reads