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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

Clin Neurophysiol 2018 Dec 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

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

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

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

Muscle Nerve 2018 Nov 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

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

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

Neurol Clin 2018 May;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

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

Am J Phys Med Rehabil 2018 Aug;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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Clin Neurol Neurosurg 2017 May 6;156:1-3. Epub 2017 Mar 6.

Department of Neurology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston Salem, NC 27157, USA. Electronic address:

Background: Botulinum is a potent neurotoxin with increasing indications for neurologic disorders. While clinical benefit manifests primarily due to local actions at the neuromuscular junction, regional and systemic effects do occur. Rarely, systemic symptoms including weakness, dysarthria, dysphagia and other side effects occur as a result of iatrogenic botulinum neurotoxicity. Read More

Conf Proc IEEE Eng Med Biol Soc 2016 08;2016:896-899

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder resulting from skeletal muscle weakness and fatigue. An early common symptom is fatigable weakness of the extrinsic ocular muscles; if symptoms remain confined to the ocular muscles after a few years, this is classified as ocular myasthenia gravis (OMG). Diagnosis of MG when there are mild, isolated ocular symptoms can be difficult, and currently available diagnostic techniques are insensitive, non-specific or technically cumbersome. Read More

Neuromuscul Disord 2017 May 2;27(5):417-418. Epub 2017 Feb 2.

Department of Neurology, The University of North Carolina, Chapel Hill, NC 27514.

Myasthenia gravis (MG) is generally caused by antibodies directed against the neuromuscular junction, including antibodies against the postsynaptic nicotinic acetylcholine receptor (AChR). Pathologic abnormalities of the thymus gland, including thymoma, are associated with MG. We report a 56-year-old woman who presented with double vision. Read More

IEEE Trans Neural Syst Rehabil Eng 2017 07 9;25(7):1018-1025. Epub 2017 Feb 9.

A new measure of neuromuscular transmission instability, motor unit potential (MUP) jitter, is introduced. MUP jitter can be estimated quickly using MUP trains (MUPTs) extracted from electromyographic (EMG) signals acquired using conventional clinical equipment and needle EMG electrodiagnostic protocols. The primary motivation for developing MUP jitter is to avoid the technical demands associated with estimating jitter using conventional single fiber EMG techniques. Read More

Biomed Eng Lett 2017 Feb 9;7(1):45-53. Epub 2017 Jan 9.

Guangdong Provincial Work Injury Rehabilitation Center, Guangzhou, 510000 China.

Simulation models are necessary for testing the performance of newly developed approaches before they can be applied to interpreting experimental data, especially when biomedical signals such as surface electromyogram (SEMG) signals are involved. A new and easily implementable surface EMG simulation model was developed in this study to simulate multi-channel SEMG signals. A single fiber action potential (SFAP) is represented by the sum of three Gaussian functions. Read More

Muscle Nerve 2017 09 23;56(3):445-448. Epub 2017 Mar 23.

Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto General Hospital, 200 Elizabeth Street, Room 5 EB 309, Toronto, Ontario, Canada, M5G 2C4.

Introduction: Electrophysiological studies play an important role in the diagnosis of myasthenia gravis (MG). The objectives of this study was to explore the correlation of jitter and decrement with various clinical symptoms and signs and disease severity.

Methods: We performed a retrospective chart review of 75 MG patients who attended the neuromuscular clinic from April 2013 to May 2014. Read More

Muscle Nerve 2017 08 12;56(2):253-257. Epub 2017 Apr 12.

Department of Neurology, Peking Union Medical College Hospital, No. 1 Shuaifuyuan, Wangfujing, Dongcheng, Beijing, China, 100730.

Introduction: We analyzed jitter recordings made with concentric needle electrode (CNE) single-fiber electromyography (SFEMG) in Lambert-Eaton myasthenia (LEM).

Methods: Fifteen subjects diagnosed with LEM were studied using CNE-SFEMG in the extensor digitorum (ED) and tibialis anterior (TA) muscles. CNE-SFEMG in the ED and TA was also used to evaluate 12 and 10 healthy controls (HCs), respectively. Read More

Muscle Nerve 2017 07 15;56(1):45-50. Epub 2017 Feb 15.

Neuromuscular Section, Department of Neurology, Box 3403, Duke University Medical Center, Durham, North Carolina, 27710, USA.

Introduction: The objective of this study was to determine if single-fiber electromyography (SFEMG) jitter accurately reflects change in severity in myasthenia gravis (MG).

Methods: We reviewed jitter and outcome data from all MG patients in our clinic who had at least 2 jitter measurements in the extensor digitorum or frontalis muscle.

Results: Change in all parameters of jitter measured with SFEMG electrodes predicted clinical change with acceptable accuracy. Read More

Muscle Nerve 2017 01 18;55(1):51-54. Epub 2016 Oct 18.

Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.

Introduction: The diagnosis of myasthenia gravis in very young infants is a challenging one. In young infants, stimulated single-fiber electromyography (StimSFEMG) is the most appropriate technique, but it has serious limitations due to the absence of reference values in this subpopulation. Here we present our efforts to derive a reference range of jitter in a patient cohort of infants <3 years of age using the extrapolated norms, or e-norms, technique. Read More

J Clin Neurophysiol 2016 Oct;33(5):469-474

*Neuromuscular Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A.; and †Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH.

Introduction: The literature lacks data on accuracy of single fiber electromyography (SFEMG) for myasthenia gravis (MG) patients followed longitudinally.

Methods: We included patients with a clinical suspicion of MG who received SFEMG and follow-up at our institution between 2003 and 2013. Data collected included demographics, symptom details, clinical deficits, other diagnostic testing results, MG medication regimen, duration on treatment, response to therapy, and ultimate diagnosis after follow-up. Read More

Clin Neurol Neurosurg 2016 Nov 29;150:84-88. Epub 2016 Aug 29.

Neuromuscular and Neurological Rare Diseases Centre, Neurology and Neurophysiology Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy. Electronic address:

Objectives: Weakness and fatigue are frequent symptoms in myotonic dystrophy type 1 (DM1), mainly as a result of muscle impairment. However, neuromuscular junction (NMJ) abnormalities could play an additional role in determining these manifestations. We aimed to document the possible NMJ involvement in DM1. Read More

Clin Neurophysiol 2016 Oct 12;127(10):3294-7. Epub 2016 Aug 12.

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

Objectives: To explore the increased diagnostic yield of repetitive nerve stimulation (RNS) following activation for myasthenia gravis (MG) diagnosis, and compare with testing an additional muscle at rest only.

Methods: We performed a retrospective chart review of patients diagnosed with MG attending the neuromuscular clinic from 2013 to 2015 and extracted data on electrophysiological studies, including frequency of decrement of 10% or above, with facial RNS at rest, and following activation.

Results: The total cohort included 102 patients with MG, 65 with generalized, and 37 with ocular MG. Read More

Muscle Nerve 2017 06 1;55(6):894-901. Epub 2017 Apr 1.

Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, 21205, USA.

Introduction: Age-associated muscle strength decline is a major contributing factor to increased late-life functional decline and comorbidity, and is strongly associated with early mortality. Although all parts of the neuromuscular system seem to be affected by aging, dying-back of motor axons likely plays a major role.

Methods: We compared the degeneration in ventral roots and neuromuscular junction denervation in young and aged mice and correlated the findings with strength and electrophysiological measures. Read More

Muscle Nerve 2017 02 16;55(2):166-170. Epub 2016 Nov 16.

Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, Toronto General Hospital 200 Elizabeth Street, Room 5 EB 309, Toronto, Ontario, Canada, M5G 2C4.

Introduction: Repetitive nerve stimulation (RNS) showing ≥ 10% decrement is considered the cutoff for myasthenia gravis (MG), but this has never been validated. The objective of this study was to find an optimal validated cutoff value for decrement on RNS.

Methods: We performed retrospective chart review of patients who had electrophysiological assessment for possible MG from 2013 to 2015. Read More

Clin J Pain 2016 07;32(7):636-42

*Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway †Department of Clinical Neurophysiology, Uppsala University, Uppsala ‡Department of Surgery, Unit of Orthopedics, Perioperative Sciences, Umeå University Hospital, Umeå, Sweden §Department of Physiology and Experimental Pathophysiology, University of Erlangen, Erlangen ∥Department of Anaesthesiology and Operative Intensive Care, Heidelberg University, Mannheim, Germany.

Objectives: Nerve growth factor (NGF) is a protein important for growth and survival, but also for modulation of sensitivity of nociceptors and sympathetic neurons. The purpose of the present study was to investigate the effects of reduced NGF signaling in patients with hereditary sensory and autonomic neuropathies type V, congenital insensitivity to pain, caused by a mutation of the NGFβ gene, including a characterization of single nociceptive fibers using microneurography (MNG).

Materials And Methods: One homozygote and 2 heterozygote patients with this mutation were examined with electromyography/neurography, thermal testing, quantitative sudomotor axon reflex test, and electrically induced axon reflex erythema in addition to MNG. Read More

J Clin Neuromuscul Dis 2016 Jun;17(4):227-38

*Department of Neurology, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, SUNY, Buffalo, NY; †Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT; Departments of ‡Neurology and §Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA.

One of the first questions asked by patients and family members when a diagnosis of amyotrophic lateral sclerosis is made is "what about stem cells?" The term "stem cells" has attractiveness to it, with the assumption that stem cell treatment (stem nerve cells) can replace lost nerve cells. There are perhaps 2 types of stem cell trials, those that are vetted by the Food and Drug Administration and those that have no official oversight and whose results are infrequently published. The issue of the latter was discussed in the last edition of this column. Read More

Muscle Nerve 2016 08 26;54(2):317-9. Epub 2016 May 26.

Department of Clinical Neurophysiology, Great Ormond Street Hospital For Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, UK.

Introduction: Our objective was to compare the effect of different low-frequency filters on jitter parameters when stimulating the orbicularis oculi.

Methods: Ten healthy volunteers were studied. Jitter was expressed as the mean consecutive difference (MCD). Read More

Muscle Nerve 2016 12 11;54(6):1034-1040. Epub 2016 Oct 11.

University Medical Centre Ljubljana, Department of Neurology, Zaloška cesta 2,1000, Ljubljana, Slovenia.

Introduction: Single fiber electromyography (SFEMG) is the most sensitive diagnostic tool for diagnosis of myasthenia gravis (MG). Its prognostic value is not known.

Methods: We retrospectively analyzed the clinical course of 232 MG patients who presented with only mild symptoms and had SFEMG of the orbicularis oculi muscle. Read More

eNeurologicalSci 2016 Sep 25;4:30-33. Epub 2016 Apr 25.

Neuro-ophthalmology Unit of the Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.

Ocular myasthenia gravis (OMG) is sometimes difficult to diagnose and is probably both under-diagnosed and misdiagnosed. We studied the epidemiological parameters, relevant serology, electromyographic (EMG) findings, and the relationship between OMG and thymoma, thymus hyperplasia and other autoimmune disorders compared to generalized MG (GMG) in a case control study of 133 patients with MG (32 patients with OMG and 101 patients with GMG). The proportion of OMG among all MG patients was relatively high (24. Read More

Chin Med J (Engl) 2016 May;129(9):1036-40

Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.

Background: Single-fiber electromyography (SFEMG) has been suggested as a quantitative method for supporting chronic partial denervation in amyotrophic lateral sclerosis (ALS) by the revised EI Escorial criteria. Although concentric needle (CN) electrodes have been used to assess jitter in myasthenia gravis patients and healthy controls, there are few reports using CN electrodes to assess motor unit instability and denervation in neurogenic diseases. The aim of this study was to determine whether quantitative changes in jitter and spike number using CN electrodes could be used for ALS studies. Read More